WO2023126494A1

WO2023126494A1 - Aerosol-generating article comprising a solid aerosol-generating substrate and a susceptor

Info

Publication number: WO2023126494A1
Application number: PCT/EP2022/088034
Authority: WO
Inventors: Chiara FASCIANI; Céline GAMBS; Jean-Yves VOLLMER
Original assignee: Philip Morris Products S.A.
Priority date: 2021-12-31
Filing date: 2022-12-29
Publication date: 2023-07-06

Abstract

An aerosol-generating article (10) for use in an aerosol-generating system, the aerosol- generating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that: (i) do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; or (ii) have a pKa at 25°C in water of less than or equal to 3.5; or (iii) do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor (44) in direct contact with the solid aerosol- generating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a total aerosol former content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight. An aerosol-generating system comprising: the aerosol-generating article; and an electrically- operated aerosol-generating device comprising an inductor configured to heat the solid aerosol- generating substrate of the aerosol-generating article.

Description

AEROSOL-GENERATING ARTICLE COMPRISING A SOLID AEROSOL-GENERATING SUBSTRATE AND A SUSCEPTOR

The invention relates to an aerosol-generating article comprising a solid aerosolgenerating substrate and a susceptor. The invention also relates to an aerosol-generating system comprising the aerosol-generating article and an electrically-operated aerosol-generating device configured to heat the aerosol-generating article.

Aerosol-generating articles in which an aerosol-generating substrate, such as a tobaccocontaining material, is heated in order to form an aerosol rather than combusted to form smoke, are known in the art. An aim of such ‘heated’ aerosol-generating articles is to reduce known harmful smoke constituents of the type produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes.

Typically in heated aerosol-generating articles, an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate. In use, volatile compounds are released from the aerosol-generating substrate by heat transfer to the aerosolgenerating substrate from the heat source and entrained in air drawn through the aerosolgenerating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

A number of handheld aerosol-generating devices configured to heat aerosol-generating substrates of heated aerosol-generating articles are known in the art. These include electrically- operated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heating elements of the aerosol-generating device to the aerosolgenerating substrate of the heated aerosol-generating article. Known handheld electrically operated aerosol-generating devices typically comprise a battery, control electronics and one or more electrical heating elements for heating the aerosol-generating substrate of a heated aerosolgenerating article designed specifically for use with the aerosol-generating device.

Some known electrically-operated aerosol-generating devices comprise an internal heating element that is configured to be inserted into the aerosol-generating substrate of a heated aerosol-generating article. For example, WO 2013/098410 A2 discloses an aerosol-generating system comprising an aerosol-generating article and an electrically-operated aerosol-generating device comprising a heating element in the form of a blade that is inserted into the aerosolgenerating substrate of the aerosol-generating article.

Other known electrically-operated aerosol-generating devices comprise one or more external heating elements. For example, WO 2020/115151 A1 discloses an aerosol-generating system comprising an aerosol-generating article and an electrically-operated aerosol-generating D/P -17A VO01

WO 2023/126494 PCT/EP2022/088034

- 2 - device comprising an external heating element that circumscribes the outer periphery of the aerosol-generating article.

Electrically-operated aerosol-generating devices comprising an inductor configured to inductively heat aerosol-generating substrates of heated aerosol-generating articles are also known in the art. For example, WO 2015/176898 A1 discloses an aerosol-generating system comprising an aerosol-generating article comprising an elongate susceptor in thermal contact with the aerosol-generating substrate and an electrically-operated aerosol-generating device having an inductor for heating the aerosol-generating substrate. In use, the fluctuating or alternating electromagnetic field produced by the inductor induces eddy currents in the susceptor, causing the susceptor to heat up as a result of one or both of resistive losses (Joule heating) and, where the susceptor is magnetic, hysteresis losses. Heat generated in the susceptor is transferred to the aerosol-generating substrate by conduction.

Solid aerosol-generating substrates for use in heated aerosol-generating articles typically comprise one or more aerosol formers, such as glycerine and propylene glycol. It is known to include flavourants in solid aerosol-generating substrates for use in heated aerosol-generating articles. It is also known to include acids in solid aerosol-generating substrates for use in heated aerosol-generating articles.

Inclusion of an acid in a solid aerosol-generating substrate for use in a heated aerosolgenerating article may advantageously enable generation of an inhalable aerosol having improved sensory properties. Inclusion of an acid in a solid aerosol-generating substrate comprising nicotine for use in a heated aerosol-generating article may advantageously enable generation of an inhalable aerosol providing improved nicotine satisfaction to a user.

However, inclusion of an acid in a solid aerosol-generating substrate for use in a heated aerosol-generating article may detrimentally affect the stability of the solid aerosol-generating substrate during storage of the heated aerosol-generating article. For example, inclusion of an acid in a solid aerosol-generating substrate comprising one or more flavourants for use in a heated aerosol-generating article may disadvantageously reduce the flavour stability of the solid aerosol-generating substrate during storage of the heated aerosol-generating article.

Inclusion of an acid in a solid aerosol-generating substrate for use in a heated aerosolgenerating article may disadvantageously lead to corrosion of components of an aerosolgenerating system comprising the heated aerosol-generating article. For example, inclusion of an acid in a solid aerosol-generating substrate for use in a heated aerosol-generating article may disadvantageously lead to corrosion of metal components of an aerosol-generating system comprising the heated aerosol-generating article. In particular, inclusion of an acid in a solid aerosol-generating substrate for use in a heated aerosol-generating article may disadvantageously lead to corrosion of non-precious metal components, such as, for example, chromium containing components, copper containing components, nickel containing components, tin containing components and zinc containing components, of an aerosolgenerating system comprising the heated aerosol-generating article.

Inclusion of an acid in a solid aerosol-generating substrate for use in a heated aerosolgenerating article may disadvantageously lead to corrosion of components of the heated aerosolgenerating article. For example, where a heated aerosol-generating article for use in an aerosolgenerating system comprises a solid aerosol-generating substrate and a susceptor, inclusion of an acid in the solid aerosol-generating substrate may disadvantageously lead to corrosion of the susceptor. In particular, where a heated aerosol-generating article for use in an aerosolgenerating system comprises a solid aerosol-generating substrate and a susceptor in direct contact with the solid aerosol-generating substrate, inclusion of an acid in the solid aerosolgenerating substrate may disadvantageously lead to corrosion of the susceptor.

Aerosol formers such as glycerine and propylene glycol are hygroscopic. Inclusion of a high aerosol former content in a solid aerosol-generating substrate for use in a heated aerosolgenerating article may disadvantageously exacerbate corrosion of components of an aerosolgenerating system comprising the heated aerosol-generating article.

Cellulose based agents are hydrophilic. Inclusion of a high cellulose based agent content in a solid aerosol-generating substrate for use in a heated aerosol-generating article may disadvantageously exacerbate corrosion of components of an aerosol-generating system comprising the heated aerosol-generating article.

It would be desirable to an aerosol-generating article comprising a solid aerosolgenerating substrate that exhibits improved stability compared to known aerosol-generating articles.

In particular, it would be desirable to provide an aerosol-generating article comprising a solid aerosol-generating substrate and a susceptor that exhibits improved stability compared to known aerosol-generating articles.

The invention relates to an aerosol-generating article for use in an aerosol-generating system. The aerosol-generating article may comprise a solid aerosol-generating substrate. The aerosol-generating article may comprise a susceptor. The susceptor may be in direct contact with the solid aerosol-generating substrate. The solid aerosol-generating substrate may comprise nicotine. The solid aerosol-generating substrate may comprise one or more aerosol formers. The solid aerosol-generating substrate may comprise one or more cellulose based agents. The solid aerosol-generating substrate may comprise one or more carboxylic acids. The one or more carboxylic acids may not contain any non-carboxyl alkyl hydroxyl groups. The one or more carboxylic acids may not contain any ketone groups. . The one or more carboxylic acids may have a pKa at 25°C in water of less than or equal to 3.5. The solid aerosol-generating substrate may have a total aerosol former content of greater than or equal to 45 percent by weight. The solid aerosol-generating substrate may have a total cellulose based agent content of greater than or equal to 35 percent by weight. The solid aerosol-generating substrate may have a total carboxylic acid content of greater than or equal to 0.5 percent by weight. The solid aerosolgenerating substrate may not comprise iota-carrageenan or kappa-carrageenan. The solid aerosol-generating substrate may remain solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius.

The invention also relates to an aerosol-generating system. The aerosol-generating system may comprise an aerosol-generating article. The aerosol-generating article may comprise a solid aerosol-generating substrate. The aerosol-generating article may comprise a susceptor. The susceptor may be in direct contact with the solid aerosol-generating substrate. The solid aerosol-generating substrate may comprise nicotine. The solid aerosol-generating substrate may comprise one or more aerosol formers. The solid aerosol-generating substrate may comprise one or more cellulose based agents. The solid aerosol-generating substrate may comprise one or more carboxylic acids. The one or more carboxylic acids may not contain any non-carboxyl alkyl hydroxyl groups. The one or more carboxylic acids may not contain any ketone groups. The one or more carboxylic acids may have a pKa at 25°C in water of less than or equal to 3.5. The solid aerosol-generating substrate may have a total aerosol former content of greater than or equal to 45 percent by weight. The solid aerosol-generating substrate may have a total cellulose based agent content of greater than or equal to 35 percent by weight. The solid aerosolgenerating substrate may have a total carboxylic acid content of greater than or equal to 0.5 percent by weight. The solid aerosol-generating substrate may not comprise iota-carrageenan or kappa-carrageenan. The solid aerosol-generating substrate may remain solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius. The aerosol-generating system may comprise an electrically-operated aerosol-generating device. The electrically- operated aerosol-generating device may comprise an inductor. The inductor may be configured to heat the solid aerosol-generating substrate of the aerosol-generating article.

According to a first aspect of the invention there is provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that: (i) do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; or (ii) have a pKa at 25°C in water of less than or equal to 3.5; or (iii) do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosolgenerating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

According to the first aspect of the invention there is provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

According to the first aspect of the invention there is provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

According to the first aspect of the invention there is provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, undecanoic acid, and C1-C10 saturated alkyl mono-carboxylic acids; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, maleic acid, and malic acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, and maleic acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids selected from fumaric acid and maleic acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In particular, according to the first aspect of the invention there is provided an aerosolgenerating article for use in an aerosol-generating system, the aerosol-generating article comprising: a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and fumaric acid; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight, a total cellulose based agent content of at least 35 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

According to the first aspect of the invention there is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate does not comprise iota-carrageenan or kappa-carrageenan.

According to the first aspect of the invention there is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate does not comprise iota-carrageenan or kappa-carrageenan.

According to the first aspect of the invention there is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate does not comprise iota-carrageenan or kappa-carrageenan.

According to the first aspect of the invention there is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius.

According to the first aspect of the invention there is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius.

According to the first aspect of the invention there is also provided an aerosol-generating article for use in an aerosol-generating system, the aerosol-generating article comprising a solid aerosol-generating substrate, the solid aerosol-generating substrate comprising nicotine, one or more aerosol formers, one or more cellulose based agents, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius.

According to a second aspect of the invention there is provided an aerosol-generating system comprising: an aerosol-generating article according to the first aspect of the invention; and an electrically-operated aerosol-generating device comprising an inductor configured to heat the solid aerosol-generating substrate of the aerosol-generating article.

It has been surprisingly found that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously improve the stability of the solid aerosol-generating substrate during storage of aerosol-generating articles according to the first aspect of the invention. In particular, it has been surprisingly found that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously improve the stability of nicotine in the solid aerosol-generating substrate during storage of aerosol-generating articles according to the first aspect of the invention.

It has surprisingly been found that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously inhibit corrosion of components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention. In particular, it has surprisingly been found that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate of aerosolgenerating articles according to the first aspect of the invention may advantageously inhibit corrosion of metal components of aerosol-generating articles according to the first aspect of the invention and metal components of aerosol-generating systems according to the second aspect of the invention.

It has been found that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosolgenerating substrate of aerosol-generating articles according to the first aspect of the invention may particularly advantageously inhibit corrosion of the susceptor of aerosol-generating articles according to the first aspect of the invention. In particular, it has been found that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may particularly advantageously inhibit corrosion of the susceptor of aerosol-generating articles according to the first aspect of the invention during storage of aerosol-generating articles according to the first aspect of the invention.

It has been surprisingly found that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosolgenerating articles according to the first aspect of the invention may advantageously improve the stability of the solid aerosol-generating substrate during storage of aerosol-generating articles according to the first aspect of the invention. In particular, it has been surprisingly found that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously improve the stability of nicotine in the solid aerosolgenerating substrate during storage of aerosol-generating articles according to the first aspect of the invention.

It has surprisingly been found that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosolgenerating articles according to the first aspect of the invention may advantageously inhibit corrosion of components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention. In particular, it has surprisingly been found that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously inhibit corrosion of metal components of aerosol-generating articles according to the first aspect of the invention and metal components of aerosol-generating systems according to the second aspect of the invention.

It has been found that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may particularly advantageously inhibit corrosion of the susceptor of aerosol-generating articles according to the first aspect of the invention. In particular, it has been found that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may particularly advantageously inhibit corrosion of the susceptor of aerosol-generating articles according to the first aspect of the invention during storage of aerosol-generating articles according to the first aspect of the invention.

Without wishing to be bound by theory, it is believed that, when included in the solid aerosol-generating substrate, carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups are less prone to oxidise other components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention than carboxylic acids that do contain non-carboxyl alkyl hydroxyl groups. Without wishing to be bound by theory, it is believed that, when included in the solid aerosol-generating substrate, carboxylic acids that do not contain any ketone groups are less prone to oxidise other components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention than carboxylic acids that do contain ketone groups. It is believed that inclusion of one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate thereby inhibits corrosion of components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention.

Without wishing to be bound by theory, it is believed that, when included in the solid aerosol-generating substrate, carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 are less prone to oxidise other components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention than carboxylic acids having a pKa at 25°C in water of greater than 3.5. It is believed that inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate thereby inhibits corrosion of components of aerosol-generating articles according to the first aspect of the invention and components of aerosol-generating systems according to the second aspect of the invention.

As used herein with reference to the invention, the term “aerosol-generating article” is used to describe an article comprising an aerosol-generating substrate that is heated to generate an inhalable aerosol for delivery to a user.

As used herein with reference to the invention, the term “aerosol” is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. The aerosol may be visible or invisible. The aerosol may include vapours of substances that are ordinarily liquid or solid at room temperature as well as solid particles, or liquid droplets, or a combination of solid particles and liquid droplets. As used herein with reference to the invention, the term “aerosol-generating substrate” is used to describe a substrate comprising aerosol-generating material that is capable of releasing upon heating volatile compounds that can generate an aerosol.

As used herein with reference to the invention, the term “solid” is used to describe an aerosol-generating substrate that has a stable size and shape and does not flow at 23°C.

As used herein with reference to the invention, the term “aerosol-generating device” is used to describe a device that interacts with the aerosol generating substrate of an aerosol generating article to generate an aerosol.

Unless stated otherwise, percentages by weight of components of the solid aerosolgenerating substrate recited herein are based on the dry weight of the solid aerosol-generating substrate.

The aerosol-generating article has a proximal end through which, in use, an aerosol exits the aerosol-generating article for delivery to a user. The proximal end of the aerosol-generating article may also be referred to as the mouth end of the aerosol-generating article. In use, a user draws on the proximal end of the aerosol-generating article in order to inhale an aerosol generated by the aerosol-generating article.

The aerosol-generating article has a distal end. The distal end is opposite the proximal end.

Components of the aerosol-generating article may be described as being upstream or downstream of one another based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article.

As used herein with reference to the invention, the term “longitudinal” is used to describe the direction between the proximal end and the distal end of the aerosol-generating article.

As used herein with reference to the invention, the term “transverse” is used to describe the direction perpendicular to the longitudinal direction. That is, the direction perpendicular to the direction between the proximal end and the distal end of the aerosol-generating article.

As used herein with reference to the invention, the term “length” is used to describe the maximum dimension of the aerosol-generating article and components of the aerosol-generating article in the longitudinal direction. That is, the maximum dimension of the aerosol-generating article and components of the aerosol-generating article in the direction between the proximal end and the distal end of the aerosol-generating article.

As used herein with reference to the invention, the term “width” is used to describe the maximum dimension of the aerosol-generating article and components of the aerosol-generating article in the transverse direction. That is, the maximum dimension of the aerosol-generating article and components of the aerosol-generating article in the direction perpendicular to the direction between the proximal end and the distal end of the aerosol-generating article. The solid aerosol-generating substrate may remain solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius. As described further below, this may advantageously reduce or eliminate crusting in aerosol-generating articles according to the first aspect of the invention.

For example, the solid aerosol-generating substrate may remain solid when heated to a temperature of between 200 degrees Celsius and 320 degrees Celsius, between 220 degrees Celsius and 300 degrees Celsius, or between 240 degrees Celsius and 280 degrees Celsius.

The solid aerosol-generating substrate may be a solid aerosol-generating film.

As used herein with reference to the invention, the term “film” is used to describe a solid aerosol-generating substrate having a thickness that is substantially less than the width or length thereof.

As used herein with reference to the invention, the term “thickness” is used to describe the minimum dimension between opposite, substantially parallel surfaces of a solid aerosolgenerating film.

The solid aerosol-generating film may have a thickness of greater than or equal to 0.05 millimetres, greater than or equal to 0.1 millimetres, greater than or equal to 0.2 millimetres, or greater than or equal to 0.3 millimetres.

The solid aerosol-generating film may have a thickness of less than or equal to

1.2 millimetres, less than or equal to 1 millimetre, less than or equal to 0.8 millimetres, less than or equal to 0.6 millimetres, or less than or equal to 0.4 millimetres.

The solid aerosol-generating film may have a thickness of between 0.05 millimetres and

1.2 millimetres, between 0.05 millimetres and 1 millimetre, between 0.05 millimetres and 0.8 millimetres, between 0.05 millimetres and 0.6 millimetres, or between 0.05 millimetres and 0.4 millimetres.

The solid aerosol-generating film may have a thickness of between 0.1 millimetres and

1.2 millimetres, between 0.1 millimetres and 1 millimetre, between 0.1 millimetres and 0.8 millimetres, between 0.1 millimetres and 0.6 millimetres, or between 0.1 millimetres and 0.4 millimetres.

The solid aerosol-generating film may have a thickness of between 0.2 millimetres and

1.2 millimetres, between 0.2 millimetres and 1 millimetre, between 0.2 millimetres and 0.8 millimetres, between 0.2 millimetres and 0.6 millimetres, or between 0.2 millimetres and 0.4 millimetres.

The solid aerosol-generating film may have a thickness of between 0.3 millimetres and

1.2 millimetres, between 0.3 millimetres and 1 millimetre, between 0.3 millimetres and 0.8 millimetres, between 0.3 millimetres and 0.6 millimetres, or between 0.3 millimetres and 0.4 millimetres. The solid aerosol-generating film may have a basis weight of greater than or equal to 85 grams per square metre, greater than or equal to 100 grams per square metre, greater than or equal to 120 grams per square metre, or greater than or equal to 140 grams per square metre.

The solid aerosol-generating film may have a basis weight of less than or equal to 300 grams per square metre, less than or equal to 280 grams per square metre, or less than or equal to 260 grams per square metre.

The solid aerosol-generating film may have a basis weight of between 85 grams per square metre and 300 grams per square metre, between 85 grams per square metre and 280 grams per square metre, or between 85 grams per square metre and 260 grams per square metre.

The solid aerosol-generating film may have a basis weight of between 100 grams per square metre and 300 grams per square metre, between 100 grams per square metre and 280 grams per square metre, or between 100 grams per square metre and 260 grams per square metre.

The solid aerosol-generating film may have a basis weight of between 120 grams per square metre and 300 grams per square metre, between 120 grams per square metre and 280 grams per square metre, or between 120 grams per square metre and 260 grams per square metre.

The solid aerosol-generating film may have a basis weight of between 140 grams per square metre and 300 grams per square metre, between 140 grams per square metre and 280 grams per square metre, or between 140 grams per square metre and 260 grams per square metre.

The solid aerosol-generating film may be formed by any suitable method. For example, the solid aerosol-generating film may be formed by batch casting, continuous casting or extrusion.

The solid aerosol-generating film may be self-supporting. In other words, the properties of the solid aerosol-generating film may be such that, even if the solid aerosol-generating film is formed by casting a slurry onto a support surface, the solid aerosol-generating film can be separated from the support surface.

The solid aerosol-generating film may be disposed on a support or the solid aerosolgenerating film may be sandwiched between other materials. This may enhance the mechanical stability of the solid aerosol-generating film. For example, the solid aerosol-generating film may be disposed on a laminar support.

The solid aerosol-generating film may be cut or otherwise divided into a plurality of strips or shreds that may be wrapped to form an aerosol-generating rod for inclusion in an aerosolgenerating article according to the first aspect of the invention. The solid aerosol-generating film may be gathered to form an aerosol-generating rod for inclusion in an aerosol-generating article according to the first aspect of the invention.

The solid aerosol-generating film may be textured. This may facilitate gathering of the solid aerosol-generating film to form an aerosol-generating rod for inclusion in an aerosolgenerating article according to the first aspect of the invention.

As used herein with reference to the invention, the term “textured” is used to describe a solid aerosol-generating film that has been crimped, embossed, debossed, perforated or otherwise deformed. Textured solid aerosol-generating film may comprise a plurality of spacedapart indentations, protrusions, perforations or a combination thereof.

The solid aerosol-generating film may be crimped.

As used herein with reference to the invention, the term “crimped” is intended to be synonymous with the term “creped” and is used to describe a solid aerosol-generating film having a plurality of substantially parallel ridges or corrugations.

The crimped solid aerosol-generating film may have a plurality of ridges or corrugations substantially parallel to the cylindrical axis of the aerosol-generating rod. This may advantageously facilitate gathering of the crimped solid aerosol-generating film to form the aerosol-generating rod.

The solid aerosol-generating film may be textured using suitable known machinery for texturing filter tow, paper and other materials.

The solid aerosol-generating film may be crimped using a crimping unit of the type described in CH-A-691156, which comprises a pair of rotatable crimping rollers. However, it will be appreciated that the solid aerosol-generating film may be textured using other suitable machinery and processes that deform or perforate the solid aerosol-generating film.

The solid aerosol-generating film may be incorporated directly into an aerosol-generating rod for inclusion in an aerosol-generating article according to the first aspect of the invention.

The solid aerosol-generating film may be applied to a laminar support before being incorporated into an aerosol-generating rod for inclusion in an aerosol-generating article according to the first aspect of the invention. For example, the solid aerosol-generating film may be applied to the surface of a sheet material. Suitable sheet materials for use as the laminar support include, but are not limited, to: paper; cardboard; and homogenised plant material. For example, the solid aerosol-generating film may be applied to a paper sheet, an aluminium coated paper sheet, or a polyethylene coated paper sheet.

The laminar support with the solid aerosol-generating film applied thereto may be cut or otherwise divided into a plurality of strips or shreds as described above.

The laminar support with the solid aerosol-generating film applied thereto may be gathered as described above. The laminar support with the solid aerosol-generating film applied thereto may be textured as described above.

The solid aerosol-generating film may be applied to a tubular support before being incorporated into an aerosol-generating rod for inclusion in an aerosol-generating article according to the first aspect of the invention. For example, the solid aerosol-generating film may be applied to the inner surface of a hollow tubular support.

The solid aerosol-generating substrate comprises nicotine.

As used herein with reference to the invention, the term “nicotine” is used to describe nicotine, a nicotine base or a nicotine salt. In embodiments in which the solid aerosol-generating substrate comprises a nicotine base or a nicotine salt, the amounts of nicotine recited herein are the amount of free base nicotine or amount of protonated nicotine, respectively.

The solid aerosol-generating substrate may comprise natural nicotine, or synthetic nicotine, or a combination of natural nicotine and synthetic nicotine.

The solid aerosol-generating substrate may have a nicotine content of greater than or equal to 0.5 percent by weight, greater than or equal to 1 percent by weight, greater than or equal to 1.5 percent by weight, or greater than or equal to 2 percent by weight.

The solid aerosol-generating substrate may have a nicotine content of less than or equal to 10 percent by weight, less than or equal to 8 percent by weight, less than or equal to 6 percent by weight, or less than or equal to 4 percent by weight.

The solid aerosol-generating substrate may have a nicotine content of between 0.5 percent by weight and 10 percent by weight, between 0.5 percent by weight and 8 percent by weight, between 0.5 percent by weight and 6 percent by weight, or between 0.5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a nicotine content of between 1 percent by weight and 10 percent by weight, between 1 percent by weight and 8 percent by weight, between 1 percent by weight and 6 percent by weight, or between 1 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a nicotine content of between 1 .5 percent by weight and 10 percent by weight, between 1 .5 percent by weight and 8 percent by weight, between 1.5 percent by weight and 6 percent by weight, or between 1 .5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a nicotine content of between 2 percent by weight and 10 percent by weight, between 2 percent by weight and 8 percent by weight, between 2 percent by weight and 6 percent by weight, or between 2 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate comprises one or more aerosol formers. As used herein with reference to the invention, the term “aerosol former” is used to describe a compound that, in use, facilitates formation of the aerosol, and that preferably is substantially resistant to thermal degradation at the operating temperature of an aerosolgenerating article or aerosol-generating system comprising the solid aerosol-generating substrate.

Examples of suitable aerosol formers include: polyhydric alcohols, such as 1 ,3-butanediol, glycerine, 1 ,3-propanediol, propylene glycol, and triethylene glycol; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

The solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 45 percent by weight.

As used herein with reference to the invention, the term “total aerosol former content” is used to describe the combined content of all aerosol formers in the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total aerosol former content of greater than or equal to 46 percent by weight, greater than or equal to 48 percent by weight, greater than or equal to 50 percent by weight, or greater than or equal to 52 percent by weight.

The solid aerosol-generating substrate may have a total aerosol former content of less than or equal to 62 percent by weight, less than or equal to 60 percent by weight, less than or equal to 58 percent by weight, less than or equal to 56 percent by weight, or less than or equal to 54 percent by weight.

The solid aerosol-generating substrate may have a total aerosol former content of between 45 percent by weight and 62 percent by weight, between 45 percent by weight and 60 percent by weight, between 45 percent by weight and 58 percent by weight, between

45 percent by weight and 56 percent by weight, or between 45 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total aerosol former content of between 42 percent by weight and 62 percent by weight, between 46 percent by weight and 60 percent by weight, between 46 percent by weight and 58 percent by weight, between

46 percent by weight and 56 percent by weight, or between 46 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total aerosol former content of between 48 percent by weight and 62 percent by weight, between 48 percent by weight and 60 percent by weight, between 48 percent by weight and 58 percent by weight, between 48 percent by weight and 56 percent by weight, or between 48 percent by weight and 54 percent by weight. The solid aerosol-generating substrate may have a total aerosol former content of between 50 percent by weight and 62 percent by weight, between 50 percent by weight and 60 percent by weight, between 50 percent by weight and 58 percent by weight, between 50 percent by weight and 56 percent by weight, or between 50 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total aerosol former content of between 52 percent by weight and 62 percent by weight, between 52 percent by weight and 60 percent by weight, between 52 percent by weight and 58 percent by weight, between 52 percent by weight and 56 percent by weight, or between 52 percent by weight and 54 percent by weight.

Preferably, the solid aerosol-generating substrate comprises one or more polyhydric alcohols.

The solid aerosol-generating substrate may have a total polyhydric alcohol content of greater than or equal to 45 percent by weight, greater than or equal to 46 percent by weight, greater than or equal to 48 percent by weight, greater than or equal to 50 percent by weight, or greater than or equal to 52 percent by weight.

As used herein with reference to the invention, the term “total polyhydric alcohol content” is used to describe the combined content of all polyhydric alcohols in the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total polyhydric alcohol content of less than or equal to 62 percent by weight, less than or equal to 60 percent by weight, less than or equal to 58 percent by weight, less than or equal to 56 percent by weight, or less than or equal to 54 percent by weight.

The solid aerosol-generating substrate may have a total polyhydric alcohol content of between 45 percent by weight and 62 percent by weight, between 45 percent by weight and 60 percent by weight, between 45 percent by weight and 58 percent by weight, between

The solid aerosol-generating substrate may have a total polyhydric alcohol content of between 46 percent by weight and 62 percent by weight, between 46 percent by weight and 60 percent by weight, between 46 percent by weight and 58 percent by weight, between

The solid aerosol-generating substrate may have a total polyhydric alcohol content of between 48 percent by weight and 62 percent by weight, between 48 percent by weight and 60 percent by weight, between 48 percent by weight and 58 percent by weight, between 48 percent by weight and 56 percent by weight, or between 48 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total polyhydric alcohol content of between 50 percent by weight and 62 percent by weight, between 50 percent by weight and 60 percent by weight, between 50 percent by weight and 58 percent by weight, between 50 percent by weight and 56 percent by weight, or between 50 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total polyhydric alcohol content of between 52 percent by weight and 62 percent by weight, between 52 percent by weight and 60 percent by weight, between 52 percent by weight and 58 percent by weight, between 52 percent by weight and 56 percent by weight, or between 52 percent by weight and 54 percent by weight.

In certain preferred embodiments, aerosol-generating articles according to the first aspect of the invention may comprise: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more polyhydric alcohols, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a total polyhydric alcohol content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In certain preferred embodiments, aerosol-generating articles according to the first aspect of the invention may comprise: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more polyhydric alcohols, and one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a total polyhydric alcohol content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In certain preferred embodiments, aerosol-generating articles according to the first aspect of the invention may comprise: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more polyhydric alcohols, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a total polyhydric alcohol content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

Preferably, the solid aerosol-generating substrate comprises one or more polyhydric alcohols selected from 1 ,3-butanediol, glycerine, 1 ,3-propanediol, propylene glycol, and triethylene glycol.

More preferably, the solid aerosol-generating substrate comprises one or more polyhydric alcohols selected from glycerine and propylene glycol.

Most preferably, the solid aerosol-generating substrate comprises glycerine.

The solid aerosol-generating substrate may have a glycerine content of greater than or equal to 35 percent by weight, greater than or equal to 40 percent by weight, greater than or equal to 45 percent by weight, greater than or equal to 46 percent by weight, greater than or equal to 48 percent by weight, greater than or equal to 50 percent by weight, or greater than or equal to 52 percent by weight.

The solid aerosol-generating substrate may have a glycerine content of less than or equal to 62 percent by weight, less than or equal to 60 percent by weight, less than or equal to 58 percent by weight, less than or equal to 56 percent by weight, or less than or equal to 54 percent by weight.

The solid aerosol-generating substrate may have a glycerine content of between 35 percent by weight and 62 percent by weight, between 35 percent by weight and 60 percent by weight, between 35 percent by weight and 58 percent by weight, between 35 percent by weight and 56 percent by weight, or between 35 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total glycerine content of between 40 percent by weight and 62 percent by weight, between 40 percent by weight and 60 percent by weight, between 40 percent by weight and 58 percent by weight, between 40 percent by weight and 56 percent by weight, or between 40 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a glycerine content of between

45 percent by weight and 62 percent by weight, between 45 percent by weight and 60 percent by weight, between 45 percent by weight and 58 percent by weight, between 45 percent by weight and 56 percent by weight, or between 45 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a glycerine content of between

46 percent by weight and 62 percent by weight, between 46 percent by weight and 60 percent by weight, between 46 percent by weight and 58 percent by weight, between 46 percent by weight and 56 percent by weight, or between 46 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a glycerine content of between 48 percent by weight and 62 percent by weight, between 48 percent by weight and 60 percent by weight, between 48 percent by weight and 58 percent by weight, between 48 percent by weight and 56 percent by weight, or between 48 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total glycerine content of between 50 percent by weight and 62 percent by weight, between 50 percent by weight and 60 percent by weight, between 50 percent by weight and 58 percent by weight, between 50 percent by weight and 56 percent by weight, or between 50 percent by weight and 54 percent by weight.

The solid aerosol-generating substrate may have a total glycerine content of between 52 percent by weight and 62 percent by weight, between 52 percent by weight and 60 percent by weight, between 52 percent by weight and 58 percent by weight, between 52 percent by weight and 56 percent by weight, or between 52 percent by weight and 54 percent by weight.

In certain preferred embodiments, aerosol-generating articles according to the first aspect of the invention may comprise: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, glycerine, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a glycerine content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In certain preferred embodiments, aerosol-generating articles according to the first aspect of the invention may comprise: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, glycerine, and one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosolgenerating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a glycerine content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

In certain preferred embodiments, aerosol-generating articles according to the first aspect of the invention may comprise: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, glycerine, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosolgenerating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a glycerine content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

The solid aerosol-generating substrate comprises one or more carboxylic acids.

The solid aerosol-generating substrate may comprise a plurality of carboxylic acids. That is, the solid aerosol-generating substrate may comprise two or more carboxylic acids. For example, the solid aerosol-generating substrate may comprise two carboxylic acids, three carboxylic acids, four carboxylic acids, or five carboxylic acids.

The solid aerosol-generating substrate may comprise one or more carboxylic acids that do not contain any non-carboxyl alky hydroxyl groups and do not contain any ketone groups.

As used herein with reference to the invention, the term “non-carboxyl alkyl hydroxyl groups” is used to describe alkyl hydroxyl groups that do not form part of a carboxyl group.

For example, the solid aerosol-generating substrate may comprise one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, fumaric acid, maleic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

The solid aerosol-generating substrate may comprise a plurality of carboxylic acids that do not contain any non-carboxyl alky hydroxyl groups and do not contain any ketone groups. For example, the solid aerosol-generating substrate may comprise benzoic acid and succinic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5.

As used herein with reference to the invention, the term “carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5” is used to describe monoprotic carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 and polyprotic carboxylic acids having a pKai at 25°C in water of less than or equal to 3.5.

For example, the solid aerosol-generating substrate may comprise one or more carboxylic acids selected from citric acid, fumaric acid, maleic acid, malic acid, oxalic acid, and salicylic acid.

The solid aerosol-generating substrate may comprise a plurality of carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5. For example, the solid aerosol-generating substrate may comprise citric acid and malic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids that do not contain any non-carboxyl alky hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5. For example, the solid aerosol-generating substrate may comprise one or more carboxylic acids selected from fumaric acid, maleic acid, oxalic acid, and salicylic acid.

The solid aerosol-generating substrate may comprise a plurality of carboxylic acids that do not contain any non-carboxyl alky hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5. For example, the solid aerosol-generating substrate may comprise fumaric acid and maleic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids having a pKa at 25°C in water of greater than or equal to 3.6.

As used herein with reference to the invention, the term “carboxylic acids having a pKa at 25°C in water of greater than or equal to 3.6” is used to describe monoprotic carboxylic acids having a pKa at 25°C in water of greater than or equal to 3.6 and polyprotic carboxylic acids having a pKai at 25°C in water of greater than or equal to 3.6.

The solid aerosol-generating substrate may comprise one or more carboxylic acids that do not contain any non-carboxyl alky hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of greater than or equal to 3.6. For example, the solid aerosolgenerating substrate may comprise one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, and succinic acid.

The solid aerosol-generating substrate may comprise a plurality of carboxylic acids that do not contain any non-carboxyl alky hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of greater than or equal to 3.6. For example, the solid aerosolgenerating substrate may comprise acetic acid and benzoic acid.

The solid aerosol-generating substrate may further comprise one or more carboxylic acids that contain a non-carboxyl alky hydroxyl group and have a pKa at 25°C in water of greater than or equal to 3.6. For example, the solid aerosol-generating substrate may further comprise lactic acid.

The solid aerosol-generating substrate may further comprise one or more carboxylic acids that contain a ketone group and have a pKa at 25°C in water of greater than or equal to 3.6. For example, the solid aerosol-generating substrate may further comprise levulinic acid.

The solid aerosol-generating substrate may comprise a plurality of carboxylic acids having a pKa at 25°C in water of greater than or equal to 3.6. For example, the solid aerosol-generating substrate may comprise benzoic acid and lactic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 and one or more carboxylic acids having a pKa at 25°C in water of greater than or equal to 3.6.

For example, the solid aerosol-generating substrate may comprise one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid and one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid, and levulinic acid.

For example, the solid aerosol-generating substrate may comprise fumaric acid and one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid, and levulinic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, undecanoic acid, and C1- C10 saturated alkyl mono-carboxylic acids.

The solid aerosol-generating substrate may comprise one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid. The solid aerosol-generating substrate may comprise one or more carboxylic acids selected from the solid aerosol-generating substrate comprises one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, maleic acid, and malic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, and maleic acid.

The solid aerosol-generating substrate may comprise one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid.

Preferably, the solid aerosol-generating substrate comprises one or more carboxylic acids selected from fumaric acid and maleic acid.

More preferably, the solid aerosol-generating substrate comprises fumaric acid.

The solid aerosol-generating substrate may further comprise one or more carboxylic acids selected from lactic acid and levulinic acid.

The solid aerosol-generating substrate has a total carboxylic acid content of greater than or equal to 0.5 percent by weight.

As used herein with reference to the invention, the term “total carboxylic acid content” is used to describe the combined content of all carboxylic acids in the solid aerosol-generating substrate. For example, where the solid aerosol-generating substrate comprises a plurality of carboxylic acids consisting of benzoic acid and fumaric acid, the term “total carboxylic acid content” describes the combined benzoic acid content and fumaric acid content of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total carboxylic acid content of greater than or equal to 1 percent by weight, greater than or equal to 1 .5 percent by weight, or greater than or equal to 2 percent by weight.

The solid aerosol-generating substrate may have a total carboxylic acid content of less than or equal to 8 percent by weight, less than or equal to 6 percent by weight, or less than or equal to 4 percent by weight.

The solid aerosol-generating substrate may have a total carboxylic acid content of between 0.5 percent by weight and 8 percent by weight, between 0.5 percent by weight and 6 percent by weight, or between 0.5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a total carboxylic acid content of between 1 percent by weight and 8 percent by weight, between 1 percent by weight and 6 percent by weight, or between 1 percent by weight and 4 percent by weight. The solid aerosol-generating substrate may have a total carboxylic acid content of between 1.5 percent by weight and 8 percent by weight, between 1.5 percent by weight and 6 percent by weight, or between 1.5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a total carboxylic acid content of between 2 percent by weight and 8 percent by weight, between 2 percent by weight and 6 percent by weight, or between 2 percent by weight and 4 percent by weight.

The molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate may be greater than or equal to 0.5:1 , greater than or equal to 1 :1 , greater than or equal to 1.5:1 , or greater than or equal to 2: 1.

The molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate may be less than or equal to 5: 1 , less than or equal to 4.5: 1 , less than or equal to 4: 1 , or less than or equal to 3.5:1.

The molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate may be between 0.5:1 and 5:1 , between 0.5:1 and 4.5:1 , between 0.5:1 and 4:1 , or between 0.5:1 and 3.5:1.

The molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate may be between 1 :1 and 5:1 , between 1 :1 and 4.5:1 , between 1 :1 and 4:1 , or between 1 :1 and 3.5:1.

The molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate may be between 1.5:1 and 5:1 , between 1.5:1 and 4.5:1 , between 1.5:1 and 4:1 , or between 1.5:1 and 3.5:1.

The molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate may be between 2:1 and 5:1 , between 2:1 and 4.5:1 , between 2:1 and 4:1 , or between 2:1 and 3.5:1.

The solid aerosol-generating substrate may have a fumaric acid content of greater than or equal to 0.5 percent by weight, greater than or equal to 1 percent by weight, greater than or equal to 1.5 percent by weight, or greater than or equal to 2 percent by weight.

The solid aerosol-generating substrate may have a fumaric acid content of less than or equal to 8 percent by weight, less than or equal to 6 percent by weight, or less than or equal to 4 percent by weight.

The solid aerosol-generating substrate may have a fumaric acid content of between 0.5 percent by weight and 8 percent by weight, between 0.5 percent by weight and 6 percent by weight, or between 0.5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a fumaric acid content of between 1 percent by weight and 8 percent by weight, between 1 percent by weight and 6 percent by weight, or between 1 percent by weight and 4 percent by weight. The solid aerosol-generating substrate may have a fumaric acid content of between 1 .5 percent by weight and 8 percent by weight, between 1 .5 percent by weight and 6 percent by weight, or between 1.5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a fumaric acid content of between 2 percent by weight and 8 percent by weight, between 2 percent by weight and 6 percent by weight, or between 2 percent by weight and 4 percent by weight.

The molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate may be greater than or equal to 0.5:1 , greater than or equal to 1 :1 , greater than or equal to 1.5:1 , or greater than or equal to 2: 1 .

The molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate may be less than or equal to 4:1 , or less than or equal to 3.5:1 , less than or equal to 3:1 , or less than or equal to 2.5:1.

The molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate may be between 0.5:1 and 4:1 , between 0.5:1 and 3.5:1 , between 0.5:1 and 3:1 , or between 0.5:1 and 2.5:1.

The molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate may be between 1 :1 and 4:1 , between 1 :1 and 3.5:1 , between 1 :1 and 3:1 , or between 1 :1 and 2.5:1.

The molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate may be between 1.5:1 and 4:1 , between 1.5:1 and 3.5:1 , between 1.5:1 and 3:1 , or between 1.5:1 and 2.5:1.

The molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate may be between 2:1 and 4: 1 , between 2:1 and 3.5:1 , between 2:1 and 3:1 , or between 2:1 and 2.5:1.

The solid aerosol-generating substrate comprises one or more cellulose based agents.

As used herein with reference to the invention, the term “cellulose based agent” is used to describe a cellulosic substance. Examples of cellulose based agents include cellulose based film-forming agents, cellulose based strengthening agents and cellulose based binding agents.

The solid aerosol-generating substrate may comprise a plurality of cellulose based agents. That is, the solid aerosol-generating substrate may comprise two or more cellulose based agents. For example, the solid aerosol-generating substrate may comprise two cellulose based agents, three cellulose based agents, four cellulose based agents, or five cellulose based agents.

The solid aerosol-generating substrate may have a total cellulose based agent content of greater than or equal to 25 percent by weight, or greater than or equal to 30 percent by weight.

As used herein with reference to the invention, the term “total cellulose based agent” is used to describe the combined content of all cellulose based agents in the solid aerosolgenerating substrate. For example, where the solid aerosol-generating substrate comprises a plurality of cellulose based agents consisting of a cellulose based film-forming agent, a cellulose based strengthening agent, and a cellulose based binding agent, the term “total cellulose based agent content” describes the combined cellulose based film-forming agent content, cellulose based strengthening agent content, and cellulose based binding agent content of the solid aerosol-generating substrate.

Preferably, the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 35 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based agent content of greater than or equal to 36 percent by weight, greater than or equal to 38 percent by weight, or greater than or equal to 40 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based agent content of less than or equal to 52 percent by weight, less than or equal to 50 percent by weight, less than or equal to 48 percent by weight, less than or equal to 46 percent by weight, or less than or equal to 44 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based agent content of between 35 percent by weight and 52 percent by weight, between 35 percent by weight and 50 percent by weight, between 35 percent by weight and 48 percent by weight, between

35 percent by weight and 46 percent by weight, or between 35 percent by weight and 44 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based agent content of between 36 percent by weight and 52 percent by weight, between 36 percent by weight and 50 percent by weight, between 36 percent by weight and 48 percent by weight, between

36 percent by weight and 46 percent by weight, or between 36 percent by weight and 44 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based agent content of between 38 percent by weight and 52 percent by weight, between 38 percent by weight and 50 percent by weight, between 38 percent by weight and 48 percent by weight, between 38 percent by weight and 46 percent by weight, or between 38 percent by weight and 44 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based agent content of between 40 percent by weight and 52 percent by weight, between 40 percent by weight and 50 percent by weight, between 40 percent by weight and 48 percent by weight, between 40 percent by weight and 46 percent by weight, or between 40 percent by weight and 44 percent by weight.

The solid aerosol-generating substrate may comprise one or more cellulose based filmforming agents. As used herein with reference to the invention, the term “cellulose based film-forming agent” is used to describe a cellulosic polymer capable, by itself or in the presence of an auxiliary thickening agent, of forming a continuous film.

Advantageously, the solid aerosol-generating substrate may comprise one or more cellulose based film-forming agents selected from carboxymethyl cellulose (CMC), ethylcellulose (EC), hydroxyethyl cellulose (HEC), hydroxyethyl methylcellulose (HEMC), hydroxypropyl cellulose (HPC), hydroxypropyl methylcellulose (HPMC), and methylcellulose (MC).

More advantageously, the solid aerosol-generating substrate may comprise one or more cellulose based film-forming agents selected from carboxymethyl cellulose (CMC), ethylcellulose (EC), methylcellulose (MC), and hydroxypropyl methylcellulose (HPMC).

Most advantageously, the solid aerosol-generating substrate comprises one or more cellulose based film-forming agents selected from carboxymethyl cellulose (CMC) and hydroxypropyl methylcellulose (HPMC).

Preferably, the solid aerosol-generating substrate comprises carboxymethyl cellulose (CMC) and hydroxypropyl methylcellulose (HPMC).

The one or more cellulose based film-forming agents may act as a binding agent for the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total cellulose based film-forming agent content of greater than or equal to 15 percent by weight, greater than or equal to 20 percent by weight, or greater than or equal to 25 percent by weight.

As used herein with reference to the invention, the term “total cellulose based film-forming agent content” is used to describe the combined content of all cellulose based film-forming agents in the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total cellulose based film-forming agent content of less than or equal to 40 percent by weight, less than or equal to 35 percent by weight, or less than or equal to 30 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based film-forming agent content of between 15 percent by weight and 40 percent by weight, between 15 percent by weight and 35 percent by weight, or between 15 percent by weight and 30 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based film-forming agent content of between 20 percent by weight and 40 percent by weight, between 20 percent by weight and 35 percent by weight, or between 20 percent by weight and 30 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based film-forming agent content of between 25 percent by weight and 40 percent by weight, between 25 percent by weight and 35 percent by weight, or between 25 percent by weight and 30 percent by weight. Inclusion of hydroxypropyl methyl cellulose in the solid aerosol-generating substrate may advantageously facilitate manufacturing of the solid aerosol-generating substrate. For example, hydroxypropylmethyl cellulose may advantageously reduce the overall viscosity of a slurry of components of the solid aerosol-generating substrate produced during manufacturing of the solid aerosol- generating substrate. A lower viscosity slurry may flow more easily and be easier to mix, transfer and handle during the manufacturing process

Hydroxypropylmethyl cellulose may advantageously act as a binding agent for the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a hydroxypropylmethyl cellulose content of greater than or equal to 14 percent by weight, greater than or equal to 16 percent by weight, greater than or equal to 18 percent by weight, or greater than or equal to 20 percent by weight.

The solid aerosol-generating substrate may have a hydroxypropylmethyl cellulose content of less than or equal to 40 percent by weight, less than or equal to 35 percent by weight, less than or equal to 30 percent by weight, or less than or equal to 25 percent by weight.

The solid aerosol-generating substrate may have a hydroxypropylmethyl cellulose content of between 14 percent by weight and 40 percent by weight, between 14 percent by weight and 35 percent by weight, between 14 percent by weight and 30 percent by weight, or between 14 percent by weight and 25 percent by weight.

The solid aerosol-generating substrate may have a hydroxypropylmethyl cellulose content of between 16 percent by weight and 40 percent by weight, between 16 percent by weight and 35 percent by weight, between 16 percent by weight and 30 percent by weight, or between 16 percent by weight and 25 percent by weight.

The solid aerosol-generating substrate may have a hydroxypropylmethyl cellulose content of between 18 percent by weight and 40 percent by weight, between 18 percent by weight and 35 percent by weight, between 18 percent by weight and 30 percent by weight, or between 18 percent by weight and 25 percent by weight.

The solid aerosol-generating substrate may have a hydroxypropylmethyl cellulose content of between 20 percent by weight and 40 percent by weight, between 20 percent by weight and 35 percent by weight, between 20 percent by weight and 30 percent by weight, or between 20 percent by weight and 25 percent by weight.

Inclusion of carboxymethyl cellulose in the solid aerosol-generating substrate may advantageously reduce or eliminate crusting in aerosol-generating articles according to the first aspect of the invention.

As used herein with reference to the invention, the term “crusting” is used to describe the formation of a solid layer on a component of the aerosol-generating article. Crusting may occur due to a component of the solid aerosol-generating substrate melting and then re-solidify around a component of the aerosol-generating article during use thereof. Crusting may be a particular problem in aerosol-generating articles according to the first aspect of the invention, which contain a susceptor in direct contact with the solid aerosol-forming substrate. If a crust is formed on the susceptor, the crusted susceptor may become less effective at heating the solid aerosol-generating substrate. This may disadvantageously lead to one or both of reduced delivery of nicotine to a user and reduced formation of aerosol from the solid aerosol-generating substrate.

The solid aerosol-generating substrate may comprise sodium carboxymethyl cellulose.

The solid aerosol-generating substrate may have a carboxymethyl cellulose content of greater than or equal to 2 percent by weight, greater than or equal to 3 percent by weight, greater than or equal to 4 percent by weight, or greater than or equal to 5 percent by weight.

The solid aerosol-generating substrate may have a carboxymethyl cellulose content of less than or equal to 12 percent by weight, less than or equal to 10 percent by weight, less than or equal to 8 percent by weight, or less than or equal to 6 percent by weight.

The solid aerosol-generating substrate may have a carboxymethyl cellulose content of between 2 percent by weight and 12 percent by weight, between 2 percent by weight and 10 percent by weight, between 2 percent by weight and 8 percent by weight, or between 2 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may have a carboxymethyl cellulose content of between 3 percent by weight and 12 percent by weight, between 3 percent by weight and 10 percent by weight, between 3 percent by weight and 8 percent by weight, or between 3 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may have a carboxymethyl cellulose content of between 4 percent by weight and 12 percent by weight, between 4 percent by weight and 10 percent by weight, between 4 percent by weight and 8 percent by weight, or between 4 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may have a carboxymethyl cellulose content of between 5 percent by weight and 12 percent by weight, between 5 percent by weight and 10 percent by weight, between 5 percent by weight and 8 percent by weight, or between 5 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may comprise one or more cellulose based strengthening agents.

Inclusion of one or more cellulose based strengthening agents in the solid aerosolgenerating substrate may advantageously increase the tensile strength of the solid aerosolgenerating substrate. In particular, where the solid aerosol-generating substrate is a solid aerosol-generating film, inclusion of one or more cellulose based strengthening agents in the solid aerosol-generating substrate may advantageously increase the tensile strength of the solid aerosol-generating film. A solid aerosol-generating substrate having a higher tensile strength may advantageously be less likely to deteriorate or break during manufacture and storage.

Advantageously, the solid aerosol-generating substrate may comprise one or more cellulose based strengthening agents selected from cellulose fibres, cellulose powder, and microcrystalline cellulose (MCC).

Preferably, the solid aerosol-generating substrate comprises cellulose fibres. Cellulose fibres may be particularly effective at increasing the tensile strength of the solid aerosolgenerating substrate.

The solid aerosol-generating substrate may have a total cellulose based strengthening agent content of greater than or equal to 5 percent by weight, greater than or equal to 10 percent by weight, or greater than or equal to 15 percent by weight.

As used herein with reference to the invention, the term “total cellulose based strengthening agent content” is used to describe the combined content of all cellulose based strengthening agents in the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total cellulose based strengthening agent content of less than or equal to 30 percent by weight, less than or equal to 25 percent by weight, or less than or equal to 20 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based strengthening agent content of between 5 percent by weight and 30 percent by weight, between 5 percent by weight and 25 percent by weight, or between 5 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based strengthening agent content of between 10 percent by weight and 30 percent by weight, between 10 percent by weight and 25 percent by weight, or between 10 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a total cellulose based strengthening agent content of between 15 percent by weight and 30 percent by weight, between 15 percent by weight and 25 percent by weight, or between 15 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may comprise cellulose fibres having a length of greater than or equal to 0.2 millimetres, greater than or equal to 0.5 millimetres, greater than or equal to 0.7 millimetres, or greater than or equal to 0.9 millimetres.

The solid aerosol-generating substrate may comprise cellulose fibres having a length of less than or equal to 2 millimetres, less than or equal to 1.8 millimetres, less than or equal to 1 .6 millimetres, or less than or equal to 1 .4 millimetres. The solid aerosol-generating substrate may comprise cellulose fibres having a length of between 0.2 millimetres and 2.0 millimetres, between 0.2 millimetres and 1 .8 millimetres, between 0.2 millimetres and 1.6 millimetres, or between 0.2 millimetres and 1.4 millimetres.

The solid aerosol-generating substrate may comprise cellulose fibres having a length of between 0.5 millimetres and 2.0 millimetres, between 0.5 millimetres and 1 .8 millimetres, between 0.5 millimetres and 1.6 millimetres, or between 0.5 millimetres and 1.4 millimetres.

The solid aerosol-generating substrate may comprise cellulose fibres having a length of between 0.7 millimetres and 2.0 millimetres, between 0.7 millimetres and 1 .8 millimetres, between 0.7 millimetres and 1.6 millimetres, or between 0.7 millimetres and 1.4 millimetres.

The solid aerosol-generating substrate may comprise cellulose fibres having a length of between 0.9 millimetres and 2.0 millimetres, between 0.9 millimetres and 1 .8 millimetres, between 0.9 millimetres and 1.6 millimetres, or between 0.9 millimetres and 1.4 millimetres.

The solid aerosol-generating substrate may have a cellulose fibre content of greater than or equal to 2 percent by weight, greater than or equal to 5 percent by weight, greater than or equal to 10 percent by weight, or greater than or equal to 15 percent by weight.

The solid aerosol-generating substrate may have a cellulose fibre content of less than or equal to 30 percent by weight, less than or equal to 25 percent by weight, or less than or equal to 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose fibre content of between 2 percent by weight and 30 percent by weight, between 2 percent by weight and 25 percent by weight, or between 2 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose fibre content of between 5 percent by weight and 30 percent by weight, between 5 percent by weight and 25 percent by weight, or between 5 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose fibre content of between 10 percent by weight and 30 percent by weight, between 10 percent by weight and 25 percent by weight, or between 10 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose fibre content of between 15 percent by weight and 30 percent by weight, between 15 percent by weight and 25 percent by weight, or between 15 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may comprise microcrystalline cellulose having a D50 size of greater than or equal to 5 micrometres, greater than or equal to 10 micrometres, or greater than or equal to 15 micrometres. As used herein with reference to the invention, the term “D50 size” describes the median particle size of a particulate material. The D50 size is the particle size which splits the distribution in half, where half of the particles are larger than the D50 size and half of the particles are smaller than the D50 size. The particle size distribution may be determined by laser diffraction. For example, the particle size distribution may be determined by laser diffraction using a Malvern Mastersizer 3000 laser diffraction particle size analyser in accordance with the manufacturer’s instructions.

The solid aerosol-generating substrate may comprise microcrystalline cellulose having a D50 size of less than or equal to 100 micrometres, less than or equal to 90 micrometres, or less than or equal to 80 micrometres.

The solid aerosol-generating substrate may comprise microcrystalline cellulose having a D50 size of between 5 micrometres and 100 micrometres, between 5 micrometres and 90 micrometres, or between 5 micrometres and 80 micrometres.

The solid aerosol-generating substrate may comprise microcrystalline cellulose having a D50 size of between 10 micrometres and 100 micrometres, between 10 micrometres and 90 micrometres, or between 10 micrometres and 80 micrometres.

The solid aerosol-generating substrate may comprise microcrystalline cellulose having a D50 size of between 15 micrometres and 100 micrometres, between 15 micrometres and 90 micrometres, or between 150 micrometres and 80 micrometres.

The solid aerosol-generating substrate may have a microcrystalline cellulose content of greater than or equal to 2 percent by weight, greater than or equal to 5 percent by weight, greater than or equal to 10 percent by weight, or greater than or equal to 15 percent by weight.

The solid aerosol-generating substrate may have a microcrystalline cellulose content of less than or equal to 30 percent by weight, less than or equal to 25 percent by weight, or less than or equal to 20 percent by weight.

The solid aerosol-generating substrate may have a microcrystalline cellulose content of between 2 percent by weight and 30 percent by weight, between 2 percent by weight and 25 percent by weight, or between 2 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a microcrystalline cellulose content of between 5 percent by weight and 30 percent by weight, between 5 percent by weight and 25 percent by weight, or between 5 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a microcrystalline cellulose content of between 10 percent by weight and 30 percent by weight, between 10 percent by weight and 25 percent by weight, or between 10 percent by weight and 20 percent by weight. The solid aerosol-generating substrate may have a microcrystalline cellulose content of between 15 percent by weight and 30 percent by weight, between 15 percent by weight and 25 percent by weight, or between 15 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may comprise cellulose powder having a D50 size of greater than or equal to 25 micrometres, greater than or equal to 30 micrometres, or greater than or equal to 35 micrometres.

The solid aerosol-generating substrate may comprise cellulose powder having a D50 size of less than or equal to 250 micrometres, less than or equal to 225 micrometres, or less than or equal to 200 micrometres.

The solid aerosol-generating substrate may comprise cellulose powder having a D50 size of between 25 micrometres and 250 micrometres, between 25 micrometres and 225 micrometres, or between 25 micrometres and 200 micrometres.

The solid aerosol-generating substrate may comprise cellulose powder having a D50 size of between 30 micrometres and 250 micrometres, between 30 micrometres and 225 micrometres, or between 30 micrometres and 200 micrometres.

The solid aerosol-generating substrate may comprise cellulose powder having a D50 size of between 35 micrometres and 250 micrometres, between 35 micrometres and 225 micrometres, or between 35 micrometres and 200 micrometres.

The solid aerosol-generating substrate may have a cellulose powder content of greater than or equal to 2 percent by weight, greater than or equal to 5 percent by weight, greater than or equal to 10 percent by weight, or greater than or equal to 15 percent by weight.

The solid aerosol-generating substrate may have a cellulose powder content of less than or equal to 30 percent by weight, less than or equal to 25 percent by weight, or less than or equal to 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose powder content of between 2 percent by weight and 30 percent by weight, between 2 percent by weight and 25 percent by weight, or between 2 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose powder content of between 5 percent by weight and 30 percent by weight, between 5 percent by weight and 25 percent by weight, or between 5 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose powder content of between 10 percent by weight and 30 percent by weight, between 10 percent by weight and 25 percent by weight, or between 10 percent by weight and 20 percent by weight.

The solid aerosol-generating substrate may have a cellulose powder content of between 15 percent by weight and 30 percent by weight, between 15 percent by weight and 25 percent by weight, or between 15 percent by weight and 20 percent by weight. The solid aerosol-generating substrate may comprise water.

The solid aerosol-generating substrate may have a water content of greater than or equal to 5 percent by weight, greater than or equal to 10 percent by weight, greater than or equal to 15 percent by weight, or greater than or equal to 17 percent by weight based on the total weight of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a water content of less than or equal to 35 percent by weight, less than or equal to 30 percent by weight, or less than or equal to 25 percent by weight based on the total weight of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a water content of between 5 percent by weight and 35 percent by weight, between 5 percent by weight and 30 percent by weight, or between 5 percent by weight and 25 percent by weight based on the total weight of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a water content of between 10 percent by weight and 35 percent by weight, between 10 percent by weight and 30 percent by weight, or between 10 percent by weight and 25 percent by weight based on the total weight of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a water content of between 15 percent by weight and 35 percent by weight, between 15 percent by weight and 30 percent by weight, or between 15 percent by weight and 25 percent by weight based on the total weight of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a water content of between 17 percent by weight and 35 percent by weight, between 17 percent by weight and 30 percent by weight, or between 17 percent by weight and 25 percent by weight based on the total weight of the solid aerosol-generating substrate.

The solid aerosol-generating substrate may comprise one or more non-cellulose based thickening agents.

As used herein with reference to the invention, the term “non-cellulose based thickening agent” is used to describe a non-cellulosic substance that, when added to an aqueous or nonaqueous liquid composition, increases the viscosity of the liquid composition without substantially modifying its other properties. The one or more non-cellulose based thickening agents may increase stability, and improve suspension of components in the liquid composition. A thickening agent may also be referred to as a “thickener” or a “rheology modifier” or “viscosifying agent”.

The solid aerosol-generating substrate may comprise one or more non-cellulose based thickening agents selected from alginates, gellan gum, guar gum, gum arabic, locust bean gum, pectins, starches, and xanthan gum. The solid aerosol-generating substrate may not comprise iota-carrageenan or kappa- carrageenan. Solid aerosol-generating substrates that do not comprise iota-carrageenan or kappa-carrageenan may advantageously remain solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius. This may advantageously reduce or eliminate crusting in aerosol-generating articles according to the first aspect of the invention.

The solid aerosol-generating substrate may not comprise agar. Solid aerosol-generating substrates that do not agar may advantageously remain solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius. This may advantageously reduce or eliminate crusting in aerosol-generating articles according to the first aspect of the invention.

The solid aerosol-generating substrate may have a total non-cellulose based thickening agent content of greater than or equal to 1 percent by weight, greater than or equal to 2 percent by weight, or greater than or equal to 3 percent by weight.

As used herein with reference to the invention, the term “total non-cellulose based thickening agent content” is used to describe the combined content of all non-cellulose based thickening agents in the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total non-cellulose based thickening agent content of less than or equal to 10 percent by weight, less than or equal to 8 percent by weight, or less than or equal to 6 percent by weight.

The solid aerosol-generating substrate may have a total non-cellulose based thickening agent content of between 1 percent by weight and 10 percent by weight, between 1 percent by weight and 8 percent by weight, or between 1 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may have a total non-cellulose based thickening agent content of between 2 percent by weight and 10 percent by weight, between 2 percent by weight and 8 percent by weight, or between 2 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may have a total non-cellulose based thickening agent content of between 3 percent by weight and 10 percent by weight, between 3 percent by weight and 8 percent by weight, or between 3 percent by weight and 6 percent by weight.

The solid aerosol-generating substrate may comprise one or more flavourants.

Suitable flavourants are known in the art and include, but are not limited to, menthol.

As used herein with reference to the invention, the term “menthol” is used to describe the compound 2-isopropyl-5-methylcyclohexanol in any of its isomeric forms.

As used herein with reference to the invention, the term “total flavourant content” is used to describe the combined content of all flavourants in the solid aerosol-generating substrate.

The solid aerosol-generating substrate may have a total flavourant content of greater than or equal to 0.5 percent by weight, greater than or equal to 1 percent by weight, greater than or equal to 2 percent by weight, or greater than or equal to 3 percent by weight. The solid aerosol-generating substrate may have a total flavourant content of less than or equal to 6 percent by weight, less than or equal to 5 percent by weight, or less than or equal to 4 percent by weight.

The solid aerosol-generating substrate may have a total flavourant content of between 0.5 percent by weight and 6 percent by weight, between 0.5 percent by weight and 5 percent by weight, or between 0.5 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may have a total flavourant content of between

1 percent by weight and 6 percent by weight, between 1 percent by weight and 5 percent by weight, or between 1 percent by weight and 4 percent by weight.

2 percent by weight and 6 percent by weight, between 2 percent by weight and 5 percent by weight, or between 2 percent by weight and 4 percent by weight.

3 percent by weight and 6 percent by weight, between 3 percent by weight and 5 percent by weight, or between 3 percent by weight and 4 percent by weight.

The solid aerosol-generating substrate may be a substantially tobacco-free solid aerosolgenerating substrate.

As used herein with reference to the invention, the term “substantially tobacco-free solid aerosol-generating substrate” is used to describe a solid aerosol-generating substrate having a tobacco content of less than 1 percent by weight. For example, the solid aerosol-generating substrate may have a tobacco content of less than 0.75 percent by weight, less than 0.5 percent by weight, or less than 0.25 percent by weight.

The solid aerosol-generating substrate may be a tobacco-free aerosol-generating film.

As used herein with reference to the invention, the term “tobacco-free solid aerosolgenerating substrate” is used to describe a solid aerosol-generating substrate having a tobacco content of 0 percent by weight.

The aerosol-generating article may have any desired shape. For example, the aerosolgenerating article may be substantially cylindrical.

The aerosol-generating article may have any desired transverse cross-section. For example, the aerosol-generating article may have a substantially circular, oval or elliptical transverse cross-section.

The aerosol-generating article may have any desired length. For example, the aerosolgenerating article may have a length of between 30 millimetres and 70 millimetres, between 35 millimetres and 65 millimetres, or between 40 millimetres and 60 millimetres. The aerosol-generating article may have any desired width. For example, the aerosolgenerating article may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres.

The aerosol-generating article may comprise an aerosol-generating rod comprising the solid aerosol-generating substrate.

The aerosol-generating article comprises a susceptor in direct contact with the solid aerosol-generating substrate.

Inclusion of one or more carboxylic acids that do not include any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously reduce or prevent corrosion of the susceptor.

Inclusion of one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously reduce or prevent corrosion of the susceptor.

Inclusion of one or more carboxylic acids that do not include any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5 in the solid aerosol-generating substrate of aerosol-generating articles according to the first aspect of the invention may advantageously reduce or prevent corrosion of the susceptor.

The susceptor may be located within an aerosol-generating rod comprising the solid aerosol-generating substrate.

The susceptor may be located within the solid aerosol-generating substrate.

The solid aerosol-generating substrate may at least partially surround the susceptor.

The solid aerosol-generating substrate may be disposed on the susceptor. For example, where the solid aerosol-generating substrate is a solid aerosol-generating film, the susceptor may be at least partially coated with the solid aerosol-generating film.

The susceptor may be at least partially embedded in the solid aerosol-generating substrate. For example, where the solid aerosol-generating substrate is a solid aerosolgenerating gel, the susceptor may be at least partially embedded in the solid aerosol-generating gel.

The susceptor may be an elongate susceptor.

As used herein with reference to the invention, the term “elongate” is used to describe a susceptor having a length that is greater than the width thereof. For example, the length of the susceptor may be at least twice the width thereof. The susceptor may have any desired length. For example, the susceptor may have a length of between 6 millimetres and 18 millimetres, between 8 millimetres and 16 millimetres, or between 10 millimetres and 14 millimetres.

The susceptor may have a length that is substantially the same as the length of the solid aerosol-generating substrate or substantially the same as the length of an aerosol-generating rod comprising the solid aerosol-generating substrate.

The susceptor may extend along a longitudinal axis of the aerosol-generating article.

The susceptor may have any desired width. For example, the susceptor may have a width of between 2 millimetres and 8 millimetres, between 3 millimetres and 7 millimetres, or between 4 millimetres and 6 millimetres.

The susceptor may have any desired thickness. For example, the susceptor may have a thickness of between 30 micrometres and 90 micrometres, between 40 micrometres and 80 micrometres, or between 50 micrometres and 70 micrometres.

The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the solid aerosol-generating substrate.

Preferably, the susceptor comprises a metal, an alloy or carbon.

The susceptor may comprise or consist of a ferromagnetic material, for example a ferromagnetic alloy, ferritic iron, or a ferromagnetic steel or stainless steel. A suitable susceptor may comprise or consist of aluminium.

The susceptor may be formed from 400 series stainless steels, for example grade 410 stainless steel, or grade 420 stainless steel, or grade 430 stainless steel. Different materials will dissipate different amounts of energy when positioned within electromagnetic fields having similar values of frequency and field strength.

The susceptor may comprise a non-metallic core with a metal layer disposed on the non- metallic core, for example metallic tracks formed on a surface of a ceramic core.

The susceptor may have a protective outer layer, for example a protective outer ceramic layer or protective outer glass layer.

The susceptor may comprise a protective outer coating formed by a glass, a ceramic, or an inert metal.

The aerosol-generating article may include one or more other components,

The one or more other components may include one or more of an upstream element, a support element, an aerosol-cooling element and a mouthpiece element.

The aerosol-generating article may comprise an upstream element located at the distal end of the aerosol-generating article.

The upstream element may be located immediately upstream of the solid aerosolgenerating substrate. The upstream element may advantageously prevent direct contact with the solid aerosolgenerating substrate. This may advantageously help to prevent displacement or deformation of the susceptor during transport and handling of the aerosol-generating article.

The upstream element may comprise a plug of porous material. For example, the upstream element may comprise a cellulose acetate plug.

The upstream element may have any desired shape. For example, the upstream element may be substantially cylindrical.

The upstream element may have any desired transverse cross-section. For example, the support element may have a substantially circular, oval or elliptical transverse cross-section.

The upstream element may have any desired length. For example, the upstream element may have a length of between 1 mm and 10 mm, between 1 mm and 8 mm, or between 1 mm and 6 mm. For example, the upstream element may have a length of between 3 mm and 10 mm, between 3 mm and 8 mm, or between 3 mm and 6 mm.

The upstream element may have any desired width. For example, the upstream element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The upstream element may have a width that is substantially the same as the width of the aerosol-generating article.

The aerosol-generating article may comprise a support element located between the solid aerosol-generating substrate and the proximal end of the aerosol-generating article.

The support element may be located immediately downstream of the solid aerosolgenerating substrate.

The support element may comprise a hollow tubular segment. For example, the support element may comprise a hollow cellulose acetate tube.

The hollow tubular segment may define a longitudinal cavity providing an unrestricted flow channel.

The support element may have any desired shape. For example, the support element may be substantially cylindrical.

The support element may have any desired transverse cross-section. For example, the support element may have a substantially circular, oval or elliptical transverse cross-section.

The support element may have any desired length. For example, the support element may have a length of between 5 mm and 15 mm, between 5 mm and 12 mm, or between 5 mm and 10 mm. For example, the support element may have a length of between 7 mm and 15 mm, between 7 mm and 12 mm, or between 7 mm and 10 mm.

The support element may have any desired width. For example, the support element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The support element may have a width that is substantially the same as the width of the aerosol-generating article.

The aerosol-generating article may comprise a mouthpiece element located at the proximal end of the aerosol-generating article.

The mouthpiece element may comprise a plug of porous material. For example, the mouthpiece element may comprise a cellulose acetate plug.

The mouthpiece element may comprise a mouth end cavity.

The mouth end cavity may be defined by a hollow tubular element provided at the proximal end of the mouthpiece element.

The mouth end cavity may be defined by a wrapper.

The mouthpiece element may have any desired shape. For example, the mouthpiece element may be substantially cylindrical.

The mouthpiece element may have any desired transverse cross-section. For example, the mouthpiece element may have a substantially circular, oval or elliptical transverse crosssection.

The mouthpiece may have any desired length. For example, the mouthpiece element may have a length of between 5 mm and 20 mm, between 5 mm and 15 mm, or between 5 mm and 10 mm. For example, the mouthpiece element may have a length of between 6 mm and 20 mm, between 6 mm and 15 mm, or between 6 mm and 10 mm. For example, the mouthpiece element may have a length of between 7 mm and 20 mm, between 7 mm and 15 mm, or between 7 mm and 10 mm.

The mouthpiece element may have any desired width. For example, the mouthpiece element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The mouthpiece element may have a width that is substantially the same as the width of the aerosol-generating article.

The aerosol-generating article may comprise an aerosol-cooling element located between the solid aerosol-generating substrate and the proximal end of the aerosol-generating article.

Where the aerosol-generating article comprises a mouthpiece element, the aerosolcooling element may be located immediately upstream of the mouthpiece element.

Where the aerosol-generating article comprises a support element, the aerosol-cooling element may be located immediately downstream of the support element.

The aerosol-cooling element may comprise a hollow tubular segment. For example, the aerosol-cooling element may comprise a hollow cellulose acetate tube.

The hollow tubular segment may define a longitudinal cavity providing an unrestricted flow channel. The aerosol-cooling element may have any desired shape. For example, the mouthpiece element may be substantially cylindrical.

The aerosol-cooling element may have any desired transverse cross-section. For example, the aerosol-cooling element may have a substantially circular, oval or elliptical transverse cross-section.

The aerosol-cooling element may have any desired length. For example, the aerosolcooling element may have a length of between 5 mm and 20 mm or between 5 mm and 15 mm. For example, the aerosol-cooling element may have a length of between 6 mm and 20 mm or between 6 mm and 15 mm. For example, the aerosol-cooling element may have a length of between 7 mm and 20 mm or between 7 mm and 15 mm.

The aerosol-cooling element may have any desired width. For example, the aerosolcooling element may have a width of between 5 millimetres and 10 millimetres, between 6 millimetres and 9 millimetres, or between 7 millimetres and 8 millimetres. The aerosol-cooling element may have a width that is substantially the same as the width of the aerosol-generating article.

The solid aerosol-generating substrate, susceptor and one or more other components of the aerosol-generating article may be assembled within one or more wrappers to form the aerosolgenerating article. For example, the solid aerosol-generating substrate, susceptor and other components of the aerosol-generating article may be assembled within one or more wrappers to form an elongate rod.

Suitable wrappers for use in aerosol-generating articles according to the first aspect of the invention are known in the art and include, but are not limited to: cigarette papers; filter plug wraps; tipping papers; metallised papers; metal foils; and metal foil-paper laminates.

The aerosol-generating article may comprise a ventilation zone located between the solid aerosol-generating substrate and the proximal end of the aerosol-generating article.

Where the aerosol-generating article comprises an aerosol-cooling element, the ventilation zone may be provided at a location along the aerosol-cooling element.

The aerosol-generating article may have a ventilation level of greater than or equal to 10 percent, greater than or equal to 15 percent, greater than or equal to 20 percent, or greater than or equal to 25 percent.

The aerosol-generating article may have a ventilation level of less than or equal to 50 percent, less than or equal to 45 percent, or less than or equal to 40 percent.

The aerosol-generating article may have a ventilation level of between 10 percent and 50 percent, between 10 percent and 45 percent, or between 10 percent and 40 percent.

The aerosol-generating article may have a ventilation level of between 15 percent and 50 percent, between 15 percent and 45 percent, or between 15 percent and 40 percent. The aerosol-generating article may have a ventilation level of between 20 percent and 50 percent, between 20 percent and 45 percent, or between 20 percent and 40 percent.

The aerosol-generating article may have a ventilation level of between 25 percent and 50 percent, between 25 percent and 45 percent, or between 25 percent and 40 percent.

The aerosol-generating article may have a ventilation level of between 30 percent and 50 percent, between 30 percent and 45 percent, or between 30 percent and 40 percent.

Aerosol-generating articles according to the first aspect of the invention may resemble conventional lit-end cigarettes.

Aerosol-generating articles according to the first aspect of the invention may be assembled using known methods and machinery.

According to the second aspect of the invention there is provided an aerosol-generating system comprising: an aerosol-generating article according to the first aspect of the invention; and an electrically-operated aerosol-generating device comprising an inductor configured to heat the solid aerosol-generating substrate of the aerosol-generating article.

The aerosol-generating system may comprise: a consumable aerosol-generating article according to the first aspect of the invention; and a reusable electrically-operated aerosolgenerating device configured to heat the solid aerosol-generating substrate of the aerosolgenerating article.

The electrically-operated aerosol-generating device may comprise a housing defining a device cavity configured to receive at least a portion of the aerosol-generating article.

The electrically-operated aerosol-generating device may comprise a housing defining a device cavity configured to receive at least a distal portion of the aerosol-generating article.

The electrically-operated aerosol-generating device may be a handheld electrically- operated aerosol-generating device.

The electrically-operated aerosol-generating device may comprise a power supply and control electronics.

The electrically-operated aerosol-generating device may comprise a battery and control electronics.

The electrically-operated aerosol-generating device may comprise an inductor comprising one or more induction coils.

Below, there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

EX1 : An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups.

EX2: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups.

EX3: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl hydroxyl groups.

EX4: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl hydroxyl groups and do not contain any ketone groups.

EX5: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids having a pKa at 25°C in water of less than or equal to 3.5.

EX6: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and have a pKa at 25°C in water of less than or equal to 3.5.

EX7: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups and have a pKa at 25°C in water of less than or equal to 3.5.

EX8: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl hydroxyl groups and have a pKa at 25°C in water of less than or equal to 3.5.

EX9: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that do not contain any non-carboxyl hydroxyl groups and do not contain any ketone groups and have a pKa at 25°C in water of less than or equal to 3.5.

EX10: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, undecanoic acid, and C1- C10 saturated alkyl mono-carboxylic acids.

EX11 : An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

EX12: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

EX13: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, maleic acid, and malic acid.

EX14: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, and maleic acid.

EX15: An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid.

EX16: An aerosol-generating article according to any one of EX1 to EX53 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids selected from fumaric acid and maleic acid.

EX17: An aerosol-generating article according to any one of EX1 to EX54 wherein the solid aerosol-generating substrate comprises fumaric acid. EX18: An aerosol-generating article according to any one of EX1 to EX17 wherein the solid aerosol-generating substrate does not comprise iota-carrageenan or kappa-carrageenan.

EX19: An aerosol-generating article according to any one of EX1 to EX18 wherein the solid aerosol-generating substrate does not comprise agar.

EX20: An aerosol-generating article according at any one of EX1 to EX19 wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius.

EX21 : An aerosol-generating article according to any one of EX1 to EX19 wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 200 degrees Celsius and 320 degrees Celsius.

EX22: An aerosol-generating article according to any one of EX1 to EX19 wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 220 degrees Celsius and 300 degrees Celsius.

EX23: An aerosol-generating article according to any one of EX1 to EX19 wherein the solid aerosol-generating substrate remains solid when heated to a temperature of between 240 degrees Celsius and 280 degrees Celsius.

EX24: An aerosol-generating article according to any one of EX1 to EX23 wherein the solid aerosol-generating substrate has a nicotine content of greater than or equal to 0.5 percent by weight.

EX25: An aerosol-generating article according to any one of EX1 to EX124 wherein the solid aerosol-generating substrate has a nicotine content of greater than or equal to 1 percent by weight.

EX26: An aerosol-generating article according to any one of EX1 to EX125 wherein the solid aerosol-generating substrate has a nicotine content of greater than or equal to 1 .5 percent by weight.

EX27: An aerosol-generating article according to any one of EX1 to EX26 wherein the solid aerosol-generating substrate has a nicotine content of greater than or equal to 2 percent by weight.

EX28: An aerosol-generating article according to any one of EX1 to EX27 wherein the solid aerosol-generating substrate has a nicotine content of less than or equal to 10 percent by weight.

EX29: An aerosol-generating article according to any one of EX1 to EX28 wherein the solid aerosol-generating substrate has a nicotine content of less than or equal to 8 percent by weight. EX30: An aerosol-generating article according to any one of EX1 to EX29 wherein the solid aerosol-generating substrate has a nicotine content of less than or equal to 6 percent by weight.

EX31 : An aerosol-generating article according to any one of EX1 to EX30 wherein the solid aerosol-generating substrate has a nicotine content of less than or equal to 4 percent by weight.

EX32: An aerosol-generating article according to any one of EX1 to EX31 wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to

45 percent by weight.

EX33: An aerosol-generating article according to any one of EX1 to EX32 wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to

46 percent by weight.

EX34: An aerosol-generating article according to any one of EX1 to EX33 wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 48 percent by weight.

EX35: An aerosol-generating article according to any one of EX1 to EX34 wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 50 percent by weight.

EX36: An aerosol-generating article according to any one of EX1 to EX35 wherein the solid aerosol-generating substrate has a total aerosol former content of greater than or equal to 52 percent by weight.

EX37: An aerosol-generating article according to any one of EX1 to EX36 wherein the solid aerosol-generating substrate has a total aerosol former content of less than or equal to 62 percent by weight.

EX38: An aerosol-generating article according to any one of EX1 to EX37 wherein the solid aerosol-generating substrate has a total aerosol former content of less than or equal to 60 percent by weight.

EX39: An aerosol-generating article according to any one of EX1 to EX38 wherein the solid aerosol-generating substrate has a total aerosol former content of less than or equal to 58 percent by weight.

EX40: An aerosol-generating article according to any one of EX1 to EX39 wherein the solid aerosol-generating substrate has a total aerosol former content of less than or equal to 56 percent by weight.

EX41 : An aerosol-generating article according to any one of EX1 to EX40 wherein the solid aerosol-generating substrate has a total aerosol former content of less than or equal to 54 percent by weight. EX42: An aerosol-generating article according to any one of EX1 to EX41 wherein the solid aerosol-generating substrate comprises one or more polyhydric alcohols.

EX43: An aerosol-generating article according to EX42 wherein the solid aerosolgenerating substrate has a total polyhydric alcohol content of greater than or equal to 45 percent by weight.

EX44: An aerosol-generating article according to EX42 or EX43 wherein the solid aerosolgenerating substrate has a total polyhydric alcohol content of greater than or equal to 46 percent by weight.

EX45: An aerosol-generating article according to any one of EX42 to EX44 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of greater than or equal to 48 percent by weight.

EX46: An aerosol-generating article according to any one of EX42 to EX45 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of greater than or equal to 50 percent by weight.

EX47: An aerosol-generating article according to any one of EX42 to EX46 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of greater than or equal to 52 percent by weight.

EX48: An aerosol-generating article according to any one of EX42 to EX47 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of less than or equal to 62 percent by weight.

EX49: An aerosol-generating article according to any one of EX42 to EX48 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of less than or equal to 60 percent by weight.

EX50: An aerosol-generating article according to any one of EX42 to EX49 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of less than or equal to 58 percent by weight.

EX51 : An aerosol-generating article according to any one of EX42 to EX50 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of less than or equal to 56 percent by weight.

EX52: An aerosol-generating article according to any one of EX42 to EX51 wherein the solid aerosol-generating substrate has a total polyhydric alcohol content of less than or equal to 54 percent by weight.

EX53: An aerosol-generating article according to any one of EX42 to EX52 wherein the solid aerosol-generating substrate comprises one or more polyhydric alcohols selected from 1 ,3- butanediol, glycerine, 1 ,3-propanediol, propylene glycol, and triethylene glycol. EX54: An aerosol-generating article according to any one of EX42 to EX53 wherein the solid aerosol-generating substrate comprises one or more polyhydric alcohols selected from glycerine and propylene glycol.

EX55: An aerosol-generating article according to any one of EX42 to EX54 wherein the solid aerosol-generating substrate comprises glycerine.

EX56: An aerosol-generating article according to EX55 wherein the solid aerosolgenerating substrate has a glycerine content of greater than or equal to 35 percent by weight.

EX57: An aerosol-generating article according to EX55 or EX56 wherein the solid aerosolgenerating substrate has a glycerine content of greater than or equal to 40 percent by weight.

EX58: An aerosol-generating article according any one of EX55 to EX57 wherein the solid aerosol-generating substrate has a glycerine content of greater than or equal to 45 percent by weight.

EX59: An aerosol-generating article according to any one of EX55 to EX58 wherein the solid aerosol-generating substrate has a glycerine content of greater than or equal to 46 percent by weight.

EX60: An aerosol-generating article according to any one of EX55 to EX59 wherein the solid aerosol-generating substrate has a glycerine content of greater than or equal to 48 percent by weight.

EX61 : An aerosol-generating article according to any one of EX55 to EX60 wherein the solid aerosol-generating substrate has a glycerine content of greater than or equal to 50 percent by weight.

EX62: An aerosol-generating article according to any one of EX55 to EX61 wherein the solid aerosol-generating substrate has a glycerine content of greater than or equal to 52 percent by weight.

EX63: An aerosol-generating article according to any one of EX55 to EX62 wherein the solid aerosol-generating substrate has a glycerine content of less than or equal to 62 percent by weight.

EX64: An aerosol-generating article according to any one of EX55 to EX63 wherein the solid aerosol-generating substrate has a glycerine content of less than or equal to 60 percent by weight.

EX65: An aerosol-generating article according to any one of EX55 to EX64 wherein the solid aerosol-generating substrate has a glycerine content of less than or equal to 58 percent by weight.

EX66: An aerosol-generating article according to any one of EX55 to EX65 wherein the solid aerosol-generating substrate has a glycerine content of less than or equal to 56 percent by weight. EX67: An aerosol-generating article according to any one of EX55 to EX66 wherein the solid aerosol-generating substrate has a glycerine content of less than or equal to 54 percent by weight.

EX68: An aerosol-generating article according to any one of EX1 to EX67 wherein the solid aerosol-generating substrate comprises a plurality of carboxylic acids.

EX69: An aerosol-generating article according to any one of EX1 to EX68 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids containing a noncarboxyl hydroxyl group.

EX70: An aerosol-generating article according to any one of EX1 to EX69 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids containing a noncarboxyl alkyl hydroxyl group.

EX71 : An aerosol-generating article according to any one of EX1 to EX70 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids containing a ketone group.

EX72: An aerosol-generating article according to any one of EX1 to EX71 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids having a pKa at 25°C in water of greater than or equal to 3.6.

EX73: An aerosol-generating article according to any one of EX1 to EX72 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids selected from acetic acid, benzoic acid, lactic acid, and levulinic acid.

EX74: An aerosol-generating article according to any one of EX1 to EX73 wherein the solid aerosol-generating substrate has a total carboxylic acid content of greater than or equal to 0.5 percent by weight.

EX75: An aerosol-generating article according to any one of EX1 to EX74 wherein the solid aerosol-generating substrate has a total carboxylic acid content of greater than or equal to

1 percent by weight.

EX76: An aerosol-generating article according to any one of EX1 to EX75 wherein the solid aerosol-generating substrate has a total carboxylic acid content of greater than or equal to 1 .5 percent by weight.

EX77: An aerosol-generating article according to any one of EX1 to EX76 wherein the solid aerosol-generating substrate has a total carboxylic acid content of greater than or equal to

2 percent by weight.

EX78: An aerosol-generating article according to any one of EX1 to EX77 wherein the solid aerosol-generating substrate has a total carboxylic acid content of less than or equal to 8 percent by weight. EX79: An aerosol-generating article according to any one of EX1 to EX78 wherein the solid aerosol-generating substrate has a total carboxylic acid content of less than or equal to 6 percent by weight.

EX80: An aerosol-generating article according to any one of EX1 to EX79 wherein the solid aerosol-generating substrate has a total carboxylic acid content of less than or equal to 4 percent by weight.

EX81 : An aerosol-generating article according to any one of EX1 to EX80 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 0.5:1.

EX82: An aerosol-generating article according to any one of EX1 to EX81 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 1 :1.

EX83: An aerosol-generating article according to any one of EX1 to EX82 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 1.5:1.

EX84: An aerosol-generating article according to any one of EX1 to EX83 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 2:1.

EX85: An aerosol-generating article according to any one of EX1 to EX84 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is less than or equal to 5:1.

EX86: An aerosol-generating article according to any one of EX1 to EX85 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is less than or equal to 4.5:1.

EX87: An aerosol-generating article according to any one of EX1 to EX86 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is less than or equal to 4:1.

EX88: An aerosol-generating article according to any one of EX1 to EX87 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is less than or equal to 3.5:1.

EX89: An aerosol-generating article according to any one of EX1 to EX88 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of greater than or equal to 0.5 percent by weight.

EX90: An aerosol-generating article according to any one of EX1 to EX89 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of greater than or equal to 1 percent by weight. EX91 : An aerosol-generating article according to any one of EX1 to EX90 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of greater than or equal to 1.5 percent by weight.

EX92: An aerosol-generating article according to any one of EX1 to EX91 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of greater than or equal to 2 percent by weight.

EX93: An aerosol-generating article according to any one of EX1 to EX92 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of less than or equal to 8 percent by weight.

EX94: An aerosol-generating article according to any one of EX1 to EX93 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of less than or equal to 6 percent by weight.

EX95: An aerosol-generating article according to any one of EX1 to EX94 wherein the solid aerosol-generating substrate comprises fumaric acid and the solid aerosol-generating substrate has a fumaric acid content of less than or equal to 4 percent by weight.

EX96: An aerosol-generating article according to any one of EX1 to EX95 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 0.5:1.

EX97: An aerosol-generating article according to any one of EX1 to EX96 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 1 :1.

EX98: An aerosol-generating article according to any one of EX1 to EX97 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 1.5:1.

EX99: An aerosol-generating article according to any one of EX1 to EX98 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is greater than or equal to 2:1.

EX100: An aerosol-generating article according to any one of EX1 to EX99 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is less than or equal to 4:1.

EX101: An aerosol-generating article according to any one of EX1 to EX100 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is less than or equal to 3.5:1.

EX102: An aerosol-generating article according to any one of EX1 to EX101 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is less than or equal to 3:1. EX103: An aerosol-generating article according to any one of EX1 to EX102 wherein the solid aerosol-generating substrate comprises fumaric acid and the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is less than or equal to 2.5:1.

EX104: An aerosol-generating article according to any one of EX1 to EX103 wherein the solid aerosol-generating substrate comprises a plurality of cellulose based agents.

EX105: An aerosol-generating article according to any one of EX1 to EX104 wherein the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 25 percent by weight.

EX106: An aerosol-generating article according to any one of EX1 to EX105 wherein the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 30 percent by weight.

EX107: An aerosol-generating article according to any one of EX1 to EX106 wherein the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 35 percent by weight.

EX108: An aerosol-generating article according to any one of EX1 to EX107 wherein the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 36 percent by weight.

EX109: An aerosol-generating article according to any one of EX1 to EX108 wherein the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 38 percent by weight.

EX110: An aerosol-generating article according to any one of EX1 to EX109 wherein the solid aerosol-generating substrate has a total cellulose based agent content of greater than or equal to 40 percent by weight.

EX111 : An aerosol-generating article according to any one of EX1 to EX110 wherein the solid aerosol-generating substrate has a total cellulose based agent content of less than or equal to 52 percent by weight.

EX112: An aerosol-generating article according to any one of EX1 to EX111 wherein the solid aerosol-generating substrate has a total cellulose based agent content of less than or equal to 50 percent by weight.

EX113: An aerosol-generating article according to any one of EX1 to EX112 wherein the solid aerosol-generating substrate has a total cellulose based agent content of less than or equal to 48 percent by weight.

EX114: An aerosol-generating article according to any one of EX1 to EX113 wherein the solid aerosol-generating substrate has a total cellulose based agent content of less than or equal to 46 percent by weight. EX115: An aerosol-generating article according to any one of EX1 to EX114 wherein the solid aerosol-generating substrate has a total cellulose based agent content of less than or equal to 44 percent by weight.

EX116: An aerosol-generating article according to any one of EX1 to EX115 wherein the solid aerosol-generating substrate comprises one or more cellulose based film-forming agents.

EX117: An aerosol-generating article according to EX116 wherein the solid aerosolgenerating substrate comprises one or more cellulose based film-forming agents selected from carboxymethyl cellulose (CMC), ethylcellulose (EC), hydroxyethyl cellulose (HEC), hydroxyethyl methylcellulose (HEMC), hydroxypropyl cellulose (HPC), hydroxypropyl methylcellulose (HPMC), and methylcellulose (MC).

EX118: An aerosol-generating article according to EX116 or EX117 wherein the solid aerosol-generating substrate comprises one or more cellulose based film-forming agents selected from carboxymethyl cellulose (CMC), ethylcellulose (EC), methylcellulose (MC), and hydroxypropyl methylcellulose (HPMC).

EX119: An aerosol-generating article according to any one of EX116 to EX118 wherein the solid aerosol-generating substrate comprises one or more cellulose based film-forming agents selected from carboxymethyl cellulose (CMC) and hydroxypropyl methylcellulose (HPMC).

EX120: An aerosol-generating article according to any one of EX116 to EX119 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose (CMC) and hydroxypropyl methylcellulose (HPMC).

EX121 : An aerosol-generating article according to any one of EX116 to EX120 wherein the one or more cellulose based film-forming agents act as a binding agent for the solid aerosolgenerating substrate.

EX122: An aerosol-generating article according to any one of EX116 to EX121 wherein the solid aerosol-generating substrate has a total cellulose based film-forming agent content of greater than or equal to 15 percent by weight.

EX123: An aerosol-generating article according to any one of EX116 to EX122 wherein the solid aerosol-generating substrate has a total cellulose based film-forming agent content of greater than or equal to 20 percent by weight.

EX124: An aerosol-generating article according to any one of EX116 to EX123 wherein the solid aerosol-generating substrate has a total cellulose based film-forming agent content of greater than or equal to 25 percent by weight.

EX125: An aerosol-generating article according to any one of EX116 to EX124 wherein the solid aerosol-generating substrate has a total cellulose based film-forming agent content of less than or equal to 40 percent by weight. EX126: An aerosol-generating article according to any one of EX116 to EX125 wherein the solid aerosol-generating substrate has a total cellulose based film-forming agent content of less than or equal to 35 percent by weight.

EX127: An aerosol-generating article according to any one of EX116 to EX126 wherein the solid aerosol-generating substrate has a total cellulose based film-forming agent content of less than or equal to 30 percent by weight.

EX128: An aerosol-generating article according to any one of EX116 to EX127 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropylmethyl cellulose content of greater than or equal to 14 percent by weight.

EX129: An aerosol-generating article according to any one of EX116 to EX128 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropylmethyl cellulose content of greater than or equal to 16 percent by weight.

EX130: An aerosol-generating article according to any one of EX116 to EX129 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropylmethyl cellulose content of greater than or equal to 18 percent by weight.

EX131: An aerosol-generating article according to any one of EX116 to EX130 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropylmethyl cellulose content of greater than or equal to 20 percent by weight.

EX132: An aerosol-generating article according to any one of EX116 to EX131 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropyl methyl cellulose content of less than or equal to 40 percent by weight.

EX133: An aerosol-generating article according to any one of EX116 to EX132 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropyl methyl cellulose content of less than or equal to 35 percent by weight.

EX134: An aerosol-generating article according to any one of EX116 to EX133 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropyl methyl cellulose content of less than or equal to 30 percent by weight.

EX135: An aerosol-generating article according to any one of EX116 to EX134 wherein the solid aerosol-generating substrate comprises hydroxypropylmethyl cellulose and the solid aerosol-generating substrate has a hydroxypropylmethyl cellulose content of less than or equal to 25 percent by weight.

EX136: An aerosol-generating article according to any one of EX116 to EX135 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of greater than or equal to 2 percent by weight.

EX137: An aerosol-generating article according to any one of EX116 to EX136 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of greater than or equal to 3 percent by weight.

EX138: An aerosol-generating article according to any one of EX116 to EX137 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of greater than or equal to 4 percent by weight.

EX139: An aerosol-generating article according to any one of EX116 to EX138 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of greater than or equal to 5 percent by weight.

EX140: An aerosol-generating article according to any one of EX116 to EX139 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of less than or equal to 12 percent by weight.

EX141: An aerosol-generating article according to any one of EX116 to EX140 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of less than or equal to 10 percent by weight.

EX142: An aerosol-generating article according to any one of EX116 to EX141 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of less than or equal to 8 percent by weight.

EX143: An aerosol-generating article according to any one of EX116 to EX142 wherein the solid aerosol-generating substrate comprises carboxymethyl cellulose and the solid aerosolgenerating substrate has a carboxymethyl cellulose content of less than or equal to 6 percent by weight.

EX144: An aerosol-generating article according to any one of EX116 to EX143 wherein the solid aerosol-generating substrate comprises sodium carboxymethyl cellulose. EX145: An aerosol-generating article according to any one of EX1 to EX144 wherein the solid aerosol-generating substrate comprises one or more cellulose based binding agents.

EX146: An aerosol-generating article according to any one of EX1 to EX145 wherein the solid aerosol-generating substrate comprises one or more cellulose based strengthening agents.

EX147: An aerosol-generating article according to EX146 wherein the solid aerosolgenerating substrate has a total cellulose based strengthening agent content of greater than or equal to 5 percent by weight.

EX148: An aerosol-generating article according to EX146 or EX147 wherein the solid aerosol-generating substrate has a total cellulose based strengthening agent content of greater than or equal to 10 percent by weight.

EX149: An aerosol-generating article according to any one of EX146 to EX148 wherein the solid aerosol-generating substrate has a total cellulose based strengthening agent content of greater than or equal to 15 percent by weight.

EX150: An aerosol-generating article according to any one of EX146 to EX149 wherein the solid aerosol-generating substrate has a total cellulose based strengthening agent content of less than or equal to 30 percent by weight.

EX151 : An aerosol-generating article according to any one of EX146 to EX150 wherein the solid aerosol-generating substrate has a total cellulose based strengthening agent content of less than or equal to 25 percent by weight.

EX152: An aerosol-generating article according to any one of EX146 to EX151 wherein the solid aerosol-generating substrate has a total cellulose based strengthening agent content of less than or equal to 20 percent by weight.

EX153: An aerosol-generating article according to any one of EX146 to EX152 wherein the solid aerosol-generating substrate comprises one or more cellulose based strengthening agents selected from cellulose fibres, cellulose powder, and microcrystalline cellulose (MCC).

EX154: An aerosol-generating article according to any one of EX146 to EX153 wherein the solid aerosol-generating substrate comprises cellulose fibres.

EX155: An aerosol-generating article according to EX154 wherein the solid aerosolgenerating substrate comprises cellulose fibres having a length of greater than or equal to 0.2 millimetres.

EX156: An aerosol-generating article according to EX154 or EX155 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of greater than or equal to 0.5 millimetres.

EX157: An aerosol-generating article according to any one of EX154 to EX156 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of greater than or equal to 0.7 millimetres. EX158: An aerosol-generating article according to any one of EX154 to EX157 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of greater than or equal to 0.9 millimetres.

EX159: An aerosol-generating article according to any one of EX154 to EX158 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of less than or equal to 2 millimetres.

EX160: An aerosol-generating article according to any one of EX154 to EX159 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of less than or equal to 1.8 millimetres.

EX161: An aerosol-generating article according to any one of EX154 to EX160 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of less than or equal to 1.6 millimetres.

EX162: An aerosol-generating article according to any one of EX154 to EX161 wherein the solid aerosol-generating substrate comprises cellulose fibres having a length of less than or equal to 1.4 millimetres.

EX163: An aerosol-generating article according to any one of EX154 to EX162 wherein the solid aerosol-generating substrate has a cellulose fibre content of greater than or equal to 2 percent by weight.

EX164: An aerosol-generating article according to any one of EX154 to EX163 wherein the solid aerosol-generating substrate has a cellulose fibre content of greater than or equal to 5 percent by weight.

EX165: An aerosol-generating article according to any one of EX154 to EX164 wherein the solid aerosol-generating substrate has a cellulose fibre content of greater than or equal to 10 percent by weight.

EX166: An aerosol-generating article according to any one of EX154 to EX165 wherein the solid aerosol-generating substrate has a cellulose fibre content of greater than or equal to 15 percent by weight.

EX167: An aerosol-generating article according to any one of EX154 to EX166 wherein the solid aerosol-generating substrate has a cellulose fibre content of less than or equal to 30 percent by weight.

EX168: An aerosol-generating article according to any one of EX154 to EX167 wherein the solid aerosol-generating substrate has a cellulose fibre content of less than or equal to 25 percent by weight.

EX169: An aerosol-generating article according to any one of EX154 to EX168 wherein the solid aerosol-generating substrate has a cellulose fibre content of less than or equal to 20 percent by weight. EX170: An aerosol-generating article according to any one of EX146 to EX169 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose.

EX171: An aerosol-generating article according to EX170 wherein the solid aerosolgenerating substrate comprises microcrystalline cellulose having a D50 size of greater than or equal to 5 micrometres.

EX172: An aerosol-generating article according to EX170 or EX171 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of greater than or equal to 10 micrometres.

EX173: An aerosol-generating article according to any one of EX170 to EX172 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of greater than or equal to 15 micrometres.

EX174: An aerosol-generating article according to any one of EX170 to EX173 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of less than or equal to 100 micrometres.

EX175: An aerosol-generating article according to any one of EX170 to EX174 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of less than or equal to 90 micrometres.

EX176: An aerosol-generating article according to any one of EX170 to EX175 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of less than or equal to 80 micrometres.

EX177: An aerosol-generating article according to any one of EX170 to EX176 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of greater than or equal to 2 percent by weight.

EX178: An aerosol-generating article according to any one of EX170 to EX177 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of greater than or equal to 5 percent by weight.

EX179: An aerosol-generating article according to any one of EX170 to EX178 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of greater than or equal to 10 percent by weight.

EX180: An aerosol-generating article according to any one of EX170 to EX179 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of greater than or equal to 15 percent by weight.

EX181: An aerosol-generating article according to any one of EX170 to EX180 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of less than or equal to 30 percent by weight. EX182: An aerosol-generating article according to any one of EX170 to EX181 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of less than or equal to 25 percent by weight.

EX183: An aerosol-generating article according to any one of EX170 to EX182 wherein the solid aerosol-generating substrate has a microcrystalline cellulose content of less than or equal to 20 percent by weight.

EX184: An aerosol-generating article according to any one of EX146 to EX183 wherein the solid aerosol-generating substrate comprises cellulose powder.

EX185: An aerosol-generating article according to EX184 wherein the solid aerosolgenerating substrate comprises cellulose powder having a D50 size of greater than or equal to 25 micrometres.

EX186: An aerosol-generating article according to EX184 or EX185 wherein the solid aerosol-generating substrate comprises cellulose powder having a D50 size of greater than or equal to 30 micrometres.

EX187: An aerosol-generating article according to any one of EX184 to EX186 wherein the solid aerosol-generating substrate comprises cellulose powder having a D50 size of greater than or equal to 35 micrometres.

EX188: An aerosol-generating article according to any one of EX184 to EX187 wherein the solid aerosol-generating substrate comprises cellulose powder having a D50 size of less than or equal to 250 micrometres.

EX189: An aerosol-generating article according to any one of EX184 to EX188 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of less than or equal to 225 micrometres.

EX190: An aerosol-generating article according to any one of EX184 to EX189 wherein the solid aerosol-generating substrate comprises microcrystalline cellulose having a D50 size of less than or equal to 200 micrometres.

EX191 : An aerosol-generating article according to any one of EX184 to EX190 wherein the solid aerosol-generating substrate has a cellulose powder content of greater than or equal to 2 percent by weight.

EX192: An aerosol-generating article according to any one of EX184 to EX191 wherein the solid aerosol-generating substrate has a cellulose powder content of greater than or equal to 5 percent by weight.

EX193: An aerosol-generating article according to any one of EX184 to EX192 wherein the solid aerosol-generating substrate has a cellulose powder content of greater than or equal to 10 percent by weight. EX194: An aerosol-generating article according to any one of EX184 to EX193 wherein the solid aerosol-generating substrate has a cellulose powder content of greater than or equal to 15 percent by weight.

EX195: An aerosol-generating article according to any one of EX184 to EX194 wherein the solid aerosol-generating substrate has a cellulose powder content of less than or equal to 30 percent by weight.

EX196: An aerosol-generating article according to any one of EX184 to EX195 wherein the solid aerosol-generating substrate has a cellulose powder content of less than or equal to 25 percent by weight.

EX197: An aerosol-generating article according to any one of EX184 to EX196 wherein the solid aerosol-generating substrate has a cellulose powder content of less than or equal to 20 percent by weight.

EX198: An aerosol-generating article according to any one of EX1 to EX197 wherein the solid aerosol-generating substrate comprises water.

EX199: An aerosol-generating article according to EX198 wherein the solid aerosolgenerating substrate has a water content of greater than or equal to 5 percent by weight based on the total weight of the solid aerosol-generating substrate.

EX200: An aerosol-generating article according to EX198 or EX199 wherein the solid aerosol-generating substrate has a water content of greater than or equal to 10 percent by weight based on the total weight of the solid aerosol-generating substrate.

EX201 : An aerosol-generating article according to any one of EX198 to EX200 wherein the solid aerosol-generating substrate has a water content of greater than or equal to 15 percent by weight based on the total weight of the solid aerosol-generating substrate.

EX202: An aerosol-generating article according to any one of EX198 to EX201 wherein the solid aerosol-generating substrate has a water content of greater than or equal to 17 percent by weight based on the total weight of the solid aerosol-generating substrate.

EX203: An aerosol-generating article according to any one of EX198 to EX202 wherein the solid aerosol-generating substrate has a water content of less than or equal to 35 percent by weight based on the total weight of the solid aerosol-generating substrate.

EX204: An aerosol-generating article according to any one of EX198 to EX203 wherein the solid aerosol-generating substrate has a water content of less than or equal to 30 percent by weight based on the total weight of the solid aerosol-generating substrate.

EX205: An aerosol-generating article according to any one of EX198 to EX204 wherein the solid aerosol-generating substrate has a water content of less than or equal to 25 percent by weight based on the total weight of the solid aerosol-generating substrate. EX206: An aerosol-generating article according to any one of EX1 to EX205 wherein the solid aerosol-generating substrate comprises one or more non-cellulose based thickening agents.

EX207: An aerosol-generating article according to EX206 wherein the solid aerosolgenerating substrate comprises one or more non-cellulose based thickening agents selected from alginates, gellan gum, guar gum, gum arabic, locust bean gum, pectins, starches, and xanthan gum.

EX208: An aerosol-generating article according to EX206 or EX207 wherein the solid aerosol-generating substrate has a total non-cellulose based thickening agent content of greater than or equal to 1 percent by weight.

EX209: An aerosol-generating article according to any one of EX206 to EX208 wherein the solid aerosol-generating substrate has a total non-cellulose based thickening agent content of greater than or equal to 2 percent by weight.

EX210: An aerosol-generating article according to any one of EX206 to EX209 wherein the solid aerosol-generating substrate has a total non-cellulose based thickening agent content of greater than or equal to 3 percent by weight.

EX211 : An aerosol-generating article according to any one of EX206 to EX210 wherein the solid aerosol-generating substrate has a total non-cellulose based thickening agent content of less than or equal to 10 percent by weight.

EX212: An aerosol-generating article according to any one of EX206 to EX211 wherein the solid aerosol-generating substrate has a total non-cellulose based thickening agent content of less than or equal to 8 percent by weight.

EX213: An aerosol-generating article according to any one of EX206 to EX212 wherein the solid aerosol-generating substrate has a total non-cellulose based thickening agent content of less than or equal to 6 percent by weight.

EX214: An aerosol-generating article according to any one of EX1 to EX213 wherein the solid aerosol-generating substrate comprises one or more flavourants.

EX215: An aerosol-generating article according to EX214 wherein the solid aerosolgenerating substrate has a total flavourant content of greater than or equal to 0.5 percent by weight.

EX216: An aerosol-generating article according to EX214 to EX215 wherein the solid aerosol-generating substrate has a total flavourant content of greater than or equal to 1 percent by weight.

EX217: An aerosol-generating article according to any one of EX214 to EX216 wherein the solid aerosol-generating substrate has a total flavourant content of greater than or equal to 2 percent by weight. EX218: An aerosol-generating article according to any one of EX214 to EX217 wherein the solid aerosol-generating substrate has a total flavourant content of greater than or equal to

3 percent by weight.

EX219: An aerosol-generating article according to any one of EX214 to EX218 wherein the solid aerosol-generating substrate has a total flavourant content of less than or equal to 6 percent by weight.

EX220: An aerosol-generating article according to any one of EX214 to EX219 wherein the solid aerosol-generating substrate has a total flavourant content of less than or equal to 5 percent by weight.

EX221 : An aerosol-generating article according to any one of EX214 to EX220 wherein the solid aerosol-generating substrate has a total flavourant content of less than or equal to

4 percent by weight.

EX222: An aerosol-generating article according to any one of EX214 to EX221 wherein the solid aerosol-generating substrate has a tobacco content of less than 1 percent by weight.

EX223: An aerosol-generating article according to any one of EX214 to EX222 wherein the solid aerosol-generating substrate has a tobacco content of less than 0.75 percent by weight.

EX224: An aerosol-generating article according to any one of EX214 to EX223 wherein the solid aerosol-generating substrate has a tobacco content of less than 0.5 percent by weight.

EX225: An aerosol-generating article according to any one of EX214 to EX209 wherein the solid aerosol-generating substrate has a tobacco content of less than 0.25 percent by weight.

EX226: An aerosol-generating article according to any one of EX214 to EX210 wherein the solid aerosol-generating substrate has a tobacco content of 0 percent by weight.

EX227: An aerosol-generating article according to any one of EX1 to EX226 wherein the solid aerosol-generating substrate is a solid aerosol-generating film.

EX228: An aerosol-generating article according to EX227 wherein the solid aerosolgenerating film has a thickness of greater than or equal to 0.05 millimetres.

EX229: An aerosol-generating article according to EX227 or EX228 wherein the solid aerosol-generating film has a thickness of greater than or equal to 0.1 millimetres.

EX230: An aerosol-generating article according to any one of EX227 to EX229 wherein the solid aerosol-generating film has a thickness of greater than or equal to 0.2 millimetres.

EX231 : An aerosol-generating article according to any one of EX227 to EX230 wherein the solid aerosol-generating film has a thickness of greater than or equal to 0.3 millimetres.

EX232: An aerosol-generating article according to any one of EX227 to EX231 wherein the solid aerosol-generating film has a thickness of less than or equal to 1.2 millimetres.

EX233: An aerosol-generating article according to any one of EX227 to EX232 wherein the solid aerosol-generating film has a thickness of less than or equal to 1 millimetre. EX234: An aerosol-generating article according to any one of EX227 to EX233 wherein the solid aerosol-generating film has a thickness of less than or equal to 0.8 millimetres.

EX235: An aerosol-generating article according to any one of EX227 to EX234 wherein the solid aerosol-generating film has a thickness of less than or equal to 0.6 millimetres.

EX236: An aerosol-generating article according to any one of EX227 to EX235 wherein the solid aerosol-generating film has a thickness of less than or equal to 0.4 millimetres.

EX237: An aerosol-generating article according to any one of EX227 to EX236 wherein the solid aerosol-generating film has a basis weight of greater than or equal to 85 grams per square metre.

EX238: An aerosol-generating article according to any one of EX227 to EX237 wherein the solid aerosol-generating film has a basis weight of greater than or equal to 90 grams per square metre.

EX239: An aerosol-generating article according to any one of EX227 to EX238 wherein the solid aerosol-generating film has a basis weight of greater than or equal to 100 grams per square metre.

EX240: An aerosol-generating article according to any one of EX227 to EX239 wherein the solid aerosol-generating film has a basis weight of greater than or equal to 120 grams per square metre.

EX241 : An aerosol-generating article according to any one of EX227 to EX240 wherein the solid aerosol-generating film has a basis weight of greater than or equal to 140 grams per square metre.

EX242: An aerosol-generating article according to any one of EX227 to EX241 wherein the solid aerosol-generating film has a basis weight of less than or equal to 300 grams per square metre.

EX243: An aerosol-generating article according to any one of EX227 to EX242 wherein the solid aerosol-generating film has a basis weight of less than or equal to 280 grams per square metre.

EX244: An aerosol-generating article according to any one of EX227 to EX243 wherein the solid aerosol-generating film has a basis weight of less than or equal to 260 grams per square metre.

EX245: An aerosol-generating article according to any one of EX227 to EX244 wherein the solid aerosol-generating film is self-supporting.

EX246: An aerosol-generating article according to any one of EX227 to EX245 wherein the solid aerosol-generating film is disposed on a support.

EX247: An aerosol-generating article according any one of EX227 to EX244 wherein the solid aerosol-generating film is disposed on a laminar support. EX248: An aerosol-generating article according to any one of EX227 to EX244 wherein the solid aerosol-generating film is disposed on a sheet material.

EX249: An aerosol-generating article according to any one of EX227 to EX244 wherein the solid aerosol-generating film is disposed on a paper sheet, an aluminium coated paper sheet, or a polyethylene coated paper sheet.

EX250: An aerosol-generating article according any one of EX227 to EX244 wherein the solid aerosol-generating film is disposed on a tubular support.

EX251 : An aerosol-generating article according any one of EX227 to EX244 wherein the solid aerosol-generating film is disposed on an inner surface of a hollow tubular support.

EX252: An aerosol-generating article according to any one of EX227 to EX251 wherein the aerosol-generating article comprises an aerosol-generating rod comprising the solid aerosolgenerating film and the solid aerosol-generating film is cut or otherwise divided into a plurality of strips or shreds that are wrapped to form the aerosol-generating rod.

EX253: An aerosol-generating article according to any one of EX227 to EX251 wherein the aerosol-generating article comprises an aerosol-generating rod comprising the solid aerosolgenerating film and the solid aerosol-generating film is gathered to form the aerosol-generating rod.

EX254: An aerosol-generating article according to EX253 wherein the solid aerosolgenerating film is textured.

EX255: An aerosol-generating article according to EX253 wherein the solid aerosolgenerating film is crimped.

EX256: An aerosol-generating article according to any one of EX1 to EX255 wherein the aerosol-generating article comprises an aerosol-generating rod comprising the solid aerosolgenerating substrate.

EX257: An aerosol-generating article according to any one of EX1 to EX256 comprising a susceptor in direct contact with the solid aerosol-generating substrate.

EX258: An aerosol-generating article according to EX257 wherein the aerosol-generating article comprises an aerosol-generating rod comprising the solid aerosol-generating substrate and the susceptor is located within the aerosol-generating rod comprising the solid aerosolgenerating substrate.

EX259: An aerosol-generating article according to EX257 or EX258 wherein the susceptor is located within the solid aerosol-generating substrate.

EX260: An aerosol-generating article according to any one of EX257 to EX259 wherein the solid aerosol-generating substrate at least partially surrounds the susceptor.

EX261 : An aerosol-generating article according to any one of EX257 to EX259 wherein the solid aerosol-generating substrate is disposed on the susceptor. EX262: An aerosol-generating article according to any one of EX257 to EX259 wherein the solid aerosol-generating substrate is a solid aerosol-generating film and the susceptor is at least partially coated with the solid aerosol-generating film.

EX263: An aerosol-generating article according to any one of EX257 to EX259 wherein the solid aerosol-generating substrate is at least partially embedded in the solid aerosolgenerating substrate.

EX264: An aerosol-generating article according to any one of EX257 to EX259 wherein the solid aerosol-generating substrate is a solid aerosol-generating gel and the susceptor is at least partially embedded in the solid aerosol-generating gel.

EX265: An aerosol-generating article according to any one of EX257 to EX264 wherein the susceptor is elongate.

EX266: An aerosol-generating article according to any one of EX257 to EX265 wherein the susceptor extends along a longitudinal axis of the aerosol-generating article.

EX267: An aerosol-generating article according to any one of EX257 to EX266 wherein the susceptor has a length of between 6 millimetres and 18 millimetres.

EX268: An aerosol-generating article according to any one of EX257 to EX267 wherein the susceptor has a length of between 8 millimetres and 16 millimetres.

EX269: An aerosol-generating article according to any one of EX257 to EX268 wherein the susceptor has a length of between 10 millimetres and 14 millimetres.

EX270: An aerosol-generating article according to any one of EX257 to EX269 wherein the susceptor has a width of between 2 millimetres and 8 millimetres.

EX271 : An aerosol-generating article according to any one of EX257 to EX270 wherein the susceptor has a width of between 3 millimetres and 7 millimetres.

EX272: An aerosol-generating article according to any one of EX257 to EX271 wherein the susceptor has a width of between 4 millimetres and 6 millimetres.

EX273: An aerosol-generating article according to any one of EX257 to EX272 wherein the susceptor has a thickness of between 30 micrometres and 90 micrometres.

EX274: An aerosol-generating article according to any one of EX257 to EX273 wherein the susceptor has a thickness of between 40 micrometres and 80 micrometres.

EX275: An aerosol-generating article according to any one of EX257 to EX274 wherein the susceptor has a thickness of between 50 micrometres and 70 micrometres.

EX276: An aerosol-generating article according to any one of EX1 to EX275 wherein the aerosol-generating article comprises an upstream element located at a distal end of the aerosolgenerating article.

EX277: An aerosol-generating article according to EX276 wherein the upstream element is located immediately upstream of the solid aerosol-generating substrate. EX278: An aerosol-generating article according to EX276 or EX277 wherein the upstream element comprises a plug of porous material.

EX279: An aerosol-generating article according to any one of EX276 to EX278 wherein the upstream element comprises a cellulose acetate plug.

EX280: An aerosol-generating article according to any one of EX1 to EX279 wherein the aerosol-generating article comprises a support element located between the solid aerosolgenerating substrate and a proximal end of the aerosol-generating article.

EX281 : An aerosol-generating article according to EX280 wherein the support element is located immediately downstream of the solid aerosol-generating substrate.

EX282: An aerosol-generating article according to EX280 or EX281 wherein the support element comprises a hollow tubular segment.

EX283: An aerosol-generating article according to any one of EX280 to EX282 wherein the hollow tubular segment defines a longitudinal cavity providing an unrestricted flow channel.

EX284: An aerosol-generating article according to any one of EX280 to EX283 wherein the support element comprises a hollow cellulose acetate tube.

EX285: An aerosol-generating article according to any one of EX1 to EX284 wherein the aerosol-generating article comprises a mouthpiece element located at a proximal end of the aerosol-generating article.

EX286: An aerosol-generating article according to EX285 wherein the mouthpiece element comprises a plug of porous material.

EX287: An aerosol-generating article according to EX285 or EX286 wherein the mouthpiece element comprise a cellulose acetate plug.

EX288: An aerosol-generating article according to any one of EX285 to EX287 wherein the mouthpiece element comprises a mouth end cavity.

EX289: An aerosol-generating article according to EX288 wherein the mouth end cavity is defined by a hollow tubular element provided at a proximal end of the mouthpiece element.

EX290: An aerosol-generating article according to EX288 wherein the mouth end cavity is defined by a wrapper.

EX291 : An aerosol-generating article according to any one of EX1 to EX290 wherein the aerosol-generating article comprises an aerosol-cooling element located between the solid aerosol-generating substrate and a proximal end of the aerosol-generating article.

EX292: An aerosol-generating article according to EX291 wherein the aerosol-generating article comprises a mouthpiece element and the aerosol-cooling element is located immediately upstream of the mouthpiece element. EX293: An aerosol-generating article according to EX291 or EX292 wherein the aerosolgenerating article comprises a support element and the aerosol-cooling element is located immediately downstream of the support element.

EX294: An aerosol-generating article according to any one of EX291 to EX293 wherein the aerosol-cooling element comprises a hollow tubular segment.

EX295: An aerosol-generating article according to any one of EX291 to EX294 wherein the hollow tubular segment defines a longitudinal cavity providing an unrestricted flow channel.

EX296: An aerosol-generating article according to any one of EX291 to EX295 wherein the aerosol-cooling element comprises a hollow cellulose acetate tube.

EX297: An aerosol-generating article according to any one of EX1 to EX296 wherein the aerosol-generating article comprises a ventilation zone located between the solid aerosolgenerating substrate and a proximal end of the aerosol-generating article.

EX298: An aerosol-generating article according to EX297 wherein the aerosol-generating article comprises an aerosol-cooling element and the ventilation zone is provided at a location along the aerosol-cooling element.

EX299: An aerosol-generating article according to EX297 or EX298 wherein the aerosolgenerating article has a ventilation level of greater than or equal to 10 percent.

EX300: An aerosol-generating article according to any one of EX297 to EX299 wherein the aerosol-generating article has a ventilation level of greater than or equal to 15 percent.

EX301 : An aerosol-generating article according to any one of EX297 to EX300 wherein the aerosol-generating article has a ventilation level of greater than or equal to 20 percent.

EX302: An aerosol-generating article according to any one of EX297 to EX301 wherein the aerosol-generating article has a ventilation level of greater than or equal to 25 percent.

EX303: An aerosol-generating article according to any one of EX297 to EX302 wherein the aerosol-generating article has a ventilation level of less than or equal to 50 percent.

EX304: An aerosol-generating article according to any one of EX297 to EX303 wherein the aerosol-generating article has a ventilation level of less than or equal to 45 percent.

EX305: An aerosol-generating article according to any one of EX297 to EX304 wherein the aerosol-generating article has a ventilation level of less than or equal to 40 percent.

EX306: An aerosol-generating system comprising: an aerosol-generating article according to any one of EX1 to EX305; and an aerosol-generating device configured to heat the solid aerosol-generating substrate of the aerosol-generating article.

EX307: An aerosol-generating system comprising: an aerosol-generating article according to any one of EX1 to EX305; and an electrically-operated aerosol-generating device configured to heat the solid aerosol-generating substrate of the aerosol-generating article. EX308: An aerosol-generating system comprising: an aerosol-generating article according to any one of EX1 to EX305; and an electrically-operated aerosol-generating device comprising an inductor configured to heat the solid aerosol-generating substrate of the aerosol-generating article.

EX309: An aerosol-generating system according to any one of EX306 to EX308 wherein the aerosol-generating device comprises a housing defining a device cavity configured to receive at least a portion of the aerosol-generating article.

EX310: An aerosol-generating system according to any one of EX306 to EX309 wherein the aerosol-generating device is a handheld aerosol-generating device.

EX311 : An aerosol-generating system according to any one of EX306 to EX310 wherein the aerosol-generating device comprises a power supply and control electronics.

EX312: An aerosol-generating system according to any one of EX306 to EX311 wherein the aerosol-generating device comprises a battery and control electronics.

EX313: An aerosol-generating system according to any one of EX306 to EX311 wherein the aerosol-generating device comprises an inductor comprising one or more induction coils.

The invention will now be further described, by way of example only, with reference to the following examples and accompanying drawings, in which:

Figure 1 is a schematic cross-sectional view of an embodiment of an aerosol-generating article according to the first aspect of the invention comprising a solid aerosol-generating substrate and a susceptor; and

Figure 2 is a schematic cross-sectional view of an embodiment of an aerosol-generating system according to the second aspect of the invention comprising the aerosol-generating article shown in Figure 1 and an electrically-operated aerosol-generating device comprising an inductor.

The aerosol-generating article 10 shown in Figure 1 comprises an aerosol-generating rod 12, a proximal section 14 located downstream of the aerosol-generating rod 12 and a distal section 16 located upstream of the aerosol-generating rod 12. As shown in Figure 1 , the aerosolgenerating article 10 has an upstream or distal end 18 and a downstream or proximal end 20. The aerosol-generating article 10 may have an overall length of 45 millimetres and an external diameter of 7.2 millimetres.

The proximal section 14 of the aerosol-generating article 10 comprises a support element 22 located immediately downstream of the aerosol-generating rod 12, an aerosol-cooling element 24 located immediately downstream of the support element 22, and a mouthpiece element 42 located immediately downstream of the aerosol-cooling element 24. The support element 22 and the aerosol-cooling element 24 together define an intermediate hollow section 50 of the aerosolgenerating article 10. The support element 22 comprises a first hollow tubular segment 26. The first hollow tubular segment 26 is in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular segment 26 defines an internal cavity 28 that extends from an upstream end 30 of the first hollow tubular segment to a downstream end 32 of the first hollow tubular segment 20. The first hollow tubular segment 26 may have a length of 8 millimetres and an external diameter of 6.9 millimetres. The first hollow tubular segment 26 may have an internal diameter of 1.9 millimetres.

The aerosol-cooling element 24 comprises a second hollow tubular segment 34. The second hollow tubular segment 34 is in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular segment 34 defines an internal cavity 36 that extends from an upstream end 38 of the second hollow tubular segment to a downstream end 40 of the second hollow tubular segment 34. The second hollow tubular segment 34 may have a length of 13 millimetres and an external diameter of 6.9 millimetres. The second hollow tubular segment

34 may have an internal diameter of 3.25 millimetres.

As shown by the dashed vertical line in Figure 1 , the aerosol-generating article 10 comprises a ventilation zone 60 provided at a location along the second hollow tubular segment 34. The ventilation zone may be provided 2 millimetres from the upstream end of the second hollow tubular segment 34. A ventilation level of the aerosol-generating article 10 may be

35 percent.

The mouthpiece element 42 is in the form of a cylindrical plug of low-density cellulose acetate. The mouthpiece element 42 may have a length of 7 millimetres and an external diameter of 6.9 millimetres.

The aerosol-generating rod 12 comprises a gathered crimped paper sheet coated with a solid aerosol-generating film having the composition shown in Example A. The aerosolgenerating rod 12 may have a length of 12 millimetres and an external diameter of 6.9 millimetres.

The aerosol-generating article 10 comprises an elongate susceptor 44 located within the aerosol-generating rod 12. As shown in Figure 2, the elongate susceptor 44 is surrounded by the gathered crimped paper sheet coated with the solid aerosol-generating film and extends along the longitudinal axis of the aerosol-generating rod 12 from an upstream end of the aerosolgenerating rod 12 to a downstream end of the aerosol-generating rod 12. The elongate susceptor 44 is in direct contact with the solid aerosol-generating film. The elongate susceptor 44 may be in the form of a strip having a length of 12 millimetres, a width of 5 millimetres and a thickness of 60 micrometres.

The distal section 16 of the aerosol-generating article 10 comprises an upstream element 46 located immediately upstream of the aerosol-generating rod 12. The upstream element 46 is in the form of a cylindrical plug of cellulose acetate circumscribed by a stiff wrapper. The upstream element 46 may have a length of 5 millimetres and an external diameter of 6.9 millimetres.

It will be appreciated that the aerosol-generating article 10 shown Figure 1 is only one example of an embodiment of an aerosol-generating article according to the first aspect of the invention and that other embodiments are possible.

The aerosol-generating system 100 shown in Figure 2 comprises the aerosol-generating article 10 shown in Figure 1 and a handheld electrically operated aerosol-generating device 110.

The aerosol-generating device 110 comprises a housing 112 defining a device cavity 114 configured to receive a distal portion of the aerosol-generating article 10.

The aerosol-generating device 110 comprises an inductor 116 configured to heat the solid aerosol-generating film in the aerosol-generating rod 12 of the aerosol-generating article 10 when the distal portion of the aerosol-generating article 10 is received in the device cavity 114.

The aerosol-generating device also comprises a power supply in the form of a battery (not shown), such as a rechargeable lithium ion battery, and control circuitry (not shown).

The inductor 116 comprises an induction coil. The control circuitry controls the supply of electrical power from the battery to the induction coil.

In use, a fluctuating or alternating electromagnetic field produced by the induction coil of the inductor 116 induces eddy currents in the elongate susceptor 44 in the aerosol-generating rod 12 of the aerosol-generating article 10, causing the elongate susceptor 44 to heat up. Heat generated in the elongate susceptor 44 is transferred to the solid aerosol-generating film in the aerosol-generating rod 12 of the aerosol-generating article 10 by conduction.

The user draws on the mouthpiece element 42 of the aerosol-generating article 10. When a user draws on the mouthpiece 142, air is drawn into the aerosol-generating article 10 through the distal end 18. The drawn air passes through the upstream element 46 to the aerosolgenerating rod 12. Heating of the solid aerosol-generating film releases volatile and semi-volatile compounds, which form an aerosol that is entrained in the drawn air as it flows through the aerosol-generating rod 12. The drawn air and entrained aerosol pass through the intermediate hollow section 50 of the aerosol-generating article 10, where they cool and condense. The cooled aerosol then passes through the mouthpiece element 42 of the aerosol-generating article 10 into the mouth of the user.

Examples

Solid aerosol-generating films - Examples A to G

Solid aerosol-generating films for use in aerosol-generating articles according to the first aspect of the invention are produced having the compositions shown in Examples A to G below. The solid aerosol- generating films of Examples A to G are prepared by:

(1) mixing the components together with water using agitation to form a slurry;

(2) casting a layer of the slurry onto a plane surface to form a film having a thickness of between 600 and 1000 micrometres; (3) leaving the film on the plane surface to solidify; and

(3) drying the film by heating the film to 140 degrees Celsius for 8 minutes to form a solid aerosol-generating film.

The solid aerosol-generating films prepared in Examples A to G are heated to a temperature of between 250 degrees Celsius and 260 degrees Celsius and simulate the conditions of use in an aerosol-generating system according to the second aspect of the invention. The nicotine and glycerine in the solid aerosol-generating films evaporate and condense to form an inhalable aerosol. The solid aerosol-generating films shrink slightly and their volume is reduced. However, the solid aerosol-generating films remain solid.

Aerosol-generating articles - Examples 1-6 and Comparative Examples 7 and 8 Aerosol-generating rods for use in aerosol-generating articles according to the first aspect of the invention having the structure shown in Figure 1 are prepared comprising gathered crimped paper sheets coated with solid aerosol-generating films having the compositions shown in Examples A to C.

Comparative aerosol-generating rods for use in aerosol-generating articles not according to the invention having the structure shown in Figure 1 are prepared comprising gathered crimped paper sheets coated with solid aerosol-generating films having the composition shown in the Comparative Example below.

Each of the aerosol-generating rods and the comparative aerosol-generating rods has a length of 12 millimetres and an external diameter of 6.9 millimetres.

Each of the aerosol-generating rods and the comparative aerosol-generating rods comprises an elongate susceptor in the form of a strip having a length of 12 millimetres, a width of 5 millimetres and a thickness of 60 micrometres extending along the longitudinal axis of the aerosol-generating rod. The elongate susceptor is in direct contact with the solid aerosolgenerating film and consists of a layer of AK Steel 430 having a thickness of 3.5 micrometres, a layer of PHYTHERM 260 (Ni-Fe-Cr alloy) supplied by Aperam having a thickness of 14 micrometres and a layer of AK Steel 430 having a thickness of 42.5 micrometres.

The susceptors in the aerosol-generating rods and the comparative aerosol-generating rods are assessed for signs of corrosion (for example, oxidation or pitting of the surface of the susceptor) immediately after production (To), 7 days after production (Ti) and 7 weeks after production (T2) by a visual inspection, using energy-dispersive X-ray spectroscopy (EDX) and using scanning electron microscopy (SEM) . The results are shown in Table 1 below. The values in columns To, T1 and T2 in Table 1 indicate the number of aerosol-generating rods in which the susceptor shows signs of corrosion and the total number of aerosol-generating rods in which the susceptor is assessed for signs of corrosion for each of the examples and comparative examples. For example, 7/10 means that there are 7 aerosol-generating rods in which the susceptor shows signs of corrosion out of a total of 10 aerosol-generating rods in which the susceptor was assessed for signs of corrosion.

As shown in Table 1 , a large proportion of the susceptors in the aerosol-generating rods of Comparative Examples 7 and 8, which comprise solid aerosol-generating films comprising lactic acid, show signs of corrosion 7 days after production (Ti) and 7 weeks after production (T2).

By contrast, only a small proportion of the susceptors in the aerosol-generating rods of Examples 5 and 6, which comprise malic acid show signs of corrosion 7 days after production (T1), and none of the susceptors in the aerosol-generating rods of Examples 1 and 2, which comprise solid aerosol-generating films comprising fumaric acid, or Examples 3 and 4, which comprise solid aerosol-generating films comprising maleic acid, show signs of corrosion 7 days after production (T1) or 7 weeks after production (T2).

The specific embodiments and examples described above illustrate, but do not limit, the invention. It is to be understood that other embodiments of the invention may be made and the specific embodiments and examples described herein are not exhaustive.

For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". In this context, therefore, a number A is understood as A ± 10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

- 79 - CLAIMS:

1. An aerosol-generating article for use in an aerosol-generating system, the aerosolgenerating article comprising: a solid aerosol-generating substrate comprising nicotine, one or more cellulose based agents, one or more aerosol formers, and one or more carboxylic acids that: (i) do not contain any non-carboxyl alkyl hydroxyl groups and do not contain any ketone groups; or (ii) have a pKa at 25°C in water of less than or equal to 3.5; or (iii) do not contain any non-carboxyl alkyl hydroxyl groups, do not contain any ketone groups, and have a pKa at 25°C in water of less than or equal to 3.5; and a susceptor in direct contact with the solid aerosol-generating substrate, wherein the solid aerosol-generating substrate has a total cellulose based agent content of at least 35 percent by weight, a total aerosol former content of greater than or equal to 45 percent by weight, and a total carboxylic acid content of at least 0.5 percent by weight.

2. An aerosol-generating article according to claim 1 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, malic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

3. An aerosol-generating article according to claim 1 or 2 wherein the solid aerosolgenerating substrate comprises one or more carboxylic acids selected from acetic acid, adipic acid, benzoic acid, citric acid, fumaric acid, maleic acid, myristic acid, oxalic acid, salicylic acid, stearic acid, succinic acid, and undecanoic acid.

4. An aerosol-generating article according to claim 1 or 2 wherein the solid aerosolgenerating substrate comprises one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, maleic acid, and malic acid.

5. An aerosol-generating article according to any one of claims 1 to 4 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids selected from acetic acid, benzoic acid, citric acid, fumaric acid, and maleic acid.

6. An aerosol-generating article according to any one of claims 1 , 2 or 4 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid. - 80 -

7. An aerosol-generating article according to any one of claims 1 to 6 wherein the solid aerosol-generating substrate comprises one or more carboxylic acids selected from fumaric acid and maleic acid.

8. An aerosol-generating article according to any one of claims 1 to 7 wherein the solid aerosol-generating substrate comprises fumaric acid.

9. An aerosol-generating article according to claim 8 wherein the molar ratio of fumaric acid to nicotine in the solid aerosol-generating substrate is between 0.5:1 and 4:1.

10. An aerosol-generating article according to any one of claims 1 to 9 wherein the solid aerosol-generating substrate does not comprise iota-carrageenan or kappa-carrageenan.

11 An aerosol-generating article according to any one of claims 1 to 10 wherein the solid aerosol-generating substrate further comprises one or more carboxylic acids selected from lactic acid and levulinic acid.

12. An aerosol-generating article according to any one of claims 1 to 11 wherein the solid aerosol-generating substrate has a total carboxylic acid content of between 1 percent and 6 percent by weight.

13. An aerosol-generating article according to any one of claims 1 to 12 wherein the molar ratio of total carboxylic acid to nicotine in the solid aerosol-generating substrate is between 0.5:1 and 5:1.

14. An aerosol-generating article according to any one of claims 1 to 13 wherein the solid aerosol-generating substrate has a total cellulose based agent content of between 35 percent by weight and 50 percent by weight.

15. An aerosol-generating article according to any one of claims 1 to 14 wherein the solid aerosol-generating substrate comprises one or more cellulose based film-forming agents selected from carboxymethyl cellulose and hydroxypropyl methylcellulose. - 81 -

16. An aerosol-generating article according to any one of claims 1 to 15 wherein the solid aerosol-generating substrate comprises one or more cellulose based strengthening agents selected from cellulose fibres, microcrystalline cellulose and cellulose powder.

17. An aerosol-generating article according to any one of claims 1 to 16 wherein the solid aerosol-generating substrate at least partially surrounds the susceptor.

18. An aerosol-generating article according to any one of claims 1 to 17 wherein the solid aerosol-generating substrate is a solid aerosol-generating film.

19. An aerosol-generating article according to any one of claims 1 to 18, wherein the solid aerosol-generating film remains solid when heated to a temperature of between 180 degrees Celsius and 350 degrees Celsius.

20. An aerosol-generating system comprising: an aerosol-generating article according to any one of claims 1 to 19; and an electrically-operated aerosol-generating device comprising an inductor configured to heat the solid aerosol-generating substrate of the aerosol-generating article.