RU2811160C1 - Method for manufacturing aerosol-generating element - Google Patents

Abstract

FIELD: aerosol-generating systems.

SUBSTANCE: group of inventions relates to a method for manufacturing an aerosol-generating element and an aerosol-generating element. A method for manufacturing an aerosol-generating element for an aerosol-generating article or system includes the steps of: obtaining a solution of a matrix polymer containing a matrix-forming polymer in water; adding a plurality of components of an aerosol-generating composition to a matrix polymer solution to form an aerosol-generating solution, wherein the components of the aerosol-generating composition comprise a polyhydric alcohol and at least one alkaloid or cannabinoid; obtaining a discrete portion of the aerosol-generating solution; adding a discrete portion of the aerosol generating solution to the solution of multivalent cross-linking cations to cross-link the matrix-forming polymer; and removing the aerosol generating element from the solution to cross-link and dry the aerosol-generating element.

EFFECT: improved encapsulated substrate characterized by increased stability and minimal leakage of the aerosol generating composition.

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Description

The present invention relates to a method for making an aerosol generating element for use in an aerosol generating device or an aerosol generating system. The present invention further relates to an aerosol generating element manufactured by the above method.

Aerosol-generating articles in which an aerosol-generating substrate, such as a nicotine-containing substrate or a tobacco-containing substrate, is heated but not burned are known in the art. Typically, in these heated smoking articles, the aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating substrate or material that may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate as a result of heat transfer from the heat source and are entrained in the air flow passing through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

A number of prior art documents describe aerosol generating devices for the use of aerosol generating articles as consumables. These devices include, for example, electrically heated aerosol generating devices, in which an aerosol is generated by transferring heat from one or more electrical heating elements of the aerosol generating device to an aerosol generating substrate in a heated aerosol generating article.

In the past, substrates for heated aerosol-generating products were often made using randomly oriented pieces, threads or strips of tobacco material. Alternatively, for example, international patent application WO-A-2012/164009 describes rods for heated aerosol-generating articles made from collected sheets of tobacco material.

International patent application WO-A-2011/101164 describes alternative rods for heated aerosol generating articles made from filaments of homogenized tobacco material, which can be made by casting, rolling, calendering or extruding a mixture containing particulate tobacco and at least one generating aerosol substance, forming a sheet of homogenized tobacco material. In alternative embodiments, the rods of WO-A-2011/101164 may be made from strands of homogenized tobacco material obtained by extruding a mixture containing particulate tobacco and at least one aerosol generating substance to form continuous samples of homogenized tobacco material.

Alternative forms of nicotine-containing substrates have also been described. For example, liquid nicotine compositions, often referred to as e-liquids, have been proposed. Said liquid compositions may be heated, for example, by a coiled electrically conductive resistive filament in an aerosol generating device. Substrates of this type may require special care in the manufacture of containers in which the liquid composition is stored to prevent unwanted leakage.

It has previously been proposed to provide an encapsulated nicotine formulation for use as an aerosol generating substrate. However, encapsulating nicotine formulations has been found to be challenging. One reason is that nicotine formulations favor hydrophilic aerosol generating agents such as glycerin and propylene glycol, making it difficult to encapsulate the formulation using commonly used hydrophilic encapsulation materials. In general, it has been found that existing encapsulation methods require a very large amount of hydrophilic encapsulation material to obtain a stable product. This, in turn, means that insufficient nicotine formulation is provided per unit volume, resulting in ineffective aerosol delivery from the encapsulated substrate.

Although hydrophobic encapsulation materials are available, these materials often require processing at relatively high temperatures, which poses the risk of deteriorating the nicotine formulation during preparation. During application, the temperatures required to produce an aerosol from the nicotine formulation may be high enough to cause degradation of the hydrophobic encapsulation material. This may result in the release of undesirable compounds into the resulting aerosol, which may undesirably affect the organoleptic properties of the aerosol.

It would be desirable to provide a new method for producing an encapsulated aerosol-generating composition, such as a nicotine-containing composition, that provides an improved encapsulated substrate characterized by increased stability and minimal leakage of the aerosol-generating composition. In particular, it would be desirable to provide a process that results in an encapsulated substrate having a maximum useful amount of aerosol-generating composition with a minimum amount of encapsulating material, thereby providing efficient aerosol delivery. In addition, it would be desirable to provide a process that results in an encapsulated substrate that provides controlled delivery of an aerosol when heated. In addition, it would be desirable to provide a method that results in the encapsulated substrate in a form that can be readily incorporated into an aerosol generating article or device and readily heated to generate an aerosol.

According to the present invention, there is provided a method for manufacturing an aerosol generating element, comprising the steps of: obtaining a solution of a matrix polymer containing a matrix-forming polymer in water; adding a plurality of components of an aerosol-generating composition to a matrix polymer solution to form an aerosol-generating solution, wherein the components of the aerosol-generating composition comprise a polyhydric alcohol and at least one alkaloid or cannabinoid; obtaining a discrete portion of the aerosol-generating solution; adding a discrete portion of the aerosol-generating solution to a solution of multivalent cross-linking cations to cross-link the matrix-forming polymer and thereby making an aerosol-generating element containing a continuous polymer matrix and an aerosol-generating composition containing components of the aerosol-generating composition dispersed in the continuous polymer matrix; and removing the aerosol generating element from the solution to cross-link and dry the aerosol generating element.

The method as defined makes it possible to produce an aerosol generating element comprising a continuous polymer matrix and an aerosol generating composition containing components of the aerosol generating composition dispersed in the continuous polymer matrix.

The present invention further provides an aerosol generating element manufactured in accordance with the method of the present invention as defined above, containing at least 60 weight percent polyhydric alcohol, at least 0.5 weight percent nicotine, and at least 0. 5 percent by weight acid.

As used herein, the term “aerosol-generating article” refers to an aerosol-generating article containing an aerosol-generating substrate that is designed to be heated, but not burned, to release volatile compounds that can form an aerosol.

As used herein, the term “aerosol generating element” refers to a discrete aerosol generating substrate in solid form containing an aerosol generating composition dispersed and encapsulated in a cross-linked polymer matrix. The structure and composition of the aerosol generating element are described in more detail below.

The aerosol generating element according to the present invention can be used as an aerosol generating substrate in an aerosol generating article.

As used herein, the term “aerosol-generating substrate” refers to a substrate that, upon heating, can release volatile compounds that can form an aerosol. In the present invention, the aerosol-generating substrate is in the form of an aerosol-generating element in which an aerosol-generating composition comprising at least one alkaloid or cannabinoid and a polyhydric alcohol is encapsulated. An aerosol produced from an aerosol-generating composition included in the aerosol-generating elements described herein is a dispersion of solid particles or liquid droplets (or a combination of solid particles and liquid droplets) in a gas. An aerosol may be visible or invisible and may include vapors of substances that are normally liquid or solid at room temperature, as well as solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

A traditional cigarette is lit when the user brings the combustion source to one end of the cigarette and draws air through the other end. The localized heat provided by the flame and the oxygen in the air drawn through the cigarette cause combustion at one end of the cigarette, and the resulting combustion results in inhaled smoke. In contrast, in heated aerosol-generating articles, aerosol is generated by heating a flavor-generating substrate, such as a tobacco-based substrate or a substrate containing an aerosol-generating substance and a flavoring agent. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is produced by transferring heat from a combustible fuel element or heat source to a physically separated aerosol-generating material.

For example, the aerosol generating articles of the invention may find particular application in aerosol generating systems comprising an electrically heated aerosol generating device having an internal heater that is configured to apply heat to one or more discrete elements of the aerosol generating substrate. As used herein, when describing the present invention, the term “aerosol generating device” is used to describe a device comprising a heating element that interacts with one or more aerosol generating elements according to the invention to generate an aerosol. During use, volatile compounds are released from the aerosol generating element or elements as a result of thermal transfer and are entrained in air drawn through the aerosol generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the consumer.

Substrates for heated aerosol-generating articles typically contain an “aerosol-generating substance,” that is, a compound or mixture of compounds that, when used, promotes the formation of an aerosol and, preferably, is substantially persistent (s) to thermal decomposition at the operating temperature of the aerosol-generating product. Examples of suitable aerosol-generating substances include: polyhydric alcohols such as propylene glycol, triethylene glycol, 1,3-butanediol and glycerol; polyhydric alcohol esters such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

The polyhydric alcohol in the aerosol-generating composition in the aerosol-generating element manufactured according to the invention is also an aerosol-generating substance within the meaning given above.

As used herein, the term “aerosol-generating composition” refers to a composition containing a plurality of components of an aerosol-generating composition that, when the aerosol-generating element is heated, evaporates to form an aerosol. The “aerosol-generating solution” obtained during the method of the present invention refers to a solution of the components of the aerosol-generating composition and the matrix-forming polymer in a suitable solvent.

As used herein, the term “matrix-forming polymer” refers to an encapsulating material in the form of a polymer that can form a three-dimensional polymer matrix by cross-linking when the matrix-forming polymer is brought into contact with a solution of multivalent cations for cross-linking. The resulting polymer matrix can trap and retain the aerosol-generating composition within its cross-linked structure. The nature of the cross-linked polymer matrix is discussed in more detail below.

As described above, the present invention provides a new method for manufacturing an aerosol generating element in which the aerosol generating composition is encapsulated in a continuous polymer matrix structure. The aerosol generating element manufactured in accordance with the invention provides a stable structure in which the aerosol generating composition can be effectively contained with minimal loss of components of the aerosol generating composition during manufacture or storage of the aerosol generating element.

Preferably, the method according to the invention allows for effective encapsulation of the aerosol generating composition while providing a significantly lower amount of encapsulating material (corresponding to the matrix-forming polymer) compared to what could previously be achieved. This allows the aerosol generating composition components, such as alkaloid or cannabinoid and polyhydric alcohol, to be maximized in the aerosol generating element. In addition, reducing the relative content of the required encapsulating material allows for more efficient aerosol production when heated, since heating of the encapsulating material occurs to a lesser extent.

The polymer matrix in the aerosol generating element provides an inert encapsulating structure for containing and immobilizing the aerosol generating composition, which is stable when heated during use of the aerosol generating element. The inventors have discovered that when heated to temperatures ranging from 150 degrees Celsius to 350 degrees Celsius, aerosol generating elements manufactured in accordance with the present invention release aerosol because they undergo a significant reduction in mass. This reduction in mass, however, is not accompanied by an equally significant reduction in volume. Without wishing to be bound by theory, it is believed that upon heating, the components of the aerosol generating composition that are initially dispersed and trapped within the continuous polymer matrix structure are substantially vaporized and released. On the other hand, the components in the structure of the continuous polymer matrix remain essentially unchanged, and the continuous polymer matrix is only partially compressed while essentially maintaining its 3D structure. Thus, encapsulating the aerosol-generating composition in a polymer-based matrix preferably provides minimal, if any, undesirable effects on the organoleptic properties of the heated aerosol.

It has been found that the aerosol generating element produced by the method of the present invention preferably provides controlled delivery of the aerosol. In addition, the aerosol delivery profile can be easily adjusted by controlling various parameters of the production method. For example, the aerosol delivery profile can be adjusted by changing the method to control parameters of the aerosol generating element, such as the size, shape, structure and composition of the aerosol generating element.

The aerosol generating element is in the form of a discrete discrete solid object that is substantially stable and rigid so that it can be easily processed and incorporated into an aerosol generating article using existing methods and techniques.

As defined above, in the method of manufacturing an aerosol generating element, an aerosol generating solution is first prepared from a matrix polymer solution and components of the aerosol generating composition. A discrete portion of the aerosol generating solution is then added to the cross-linking solution to cross-link the matrix-forming polymer and form a polymer matrix. The resulting aerosol generating element is removed from the cross-linking solution and dried. Each of the steps of the method is described in more detail below.

In the first step of the method according to the present invention, a matrix polymer solution is prepared, which is a solution of the matrix-forming polymer in water. Preferably, the matrix polymer solution contains at least about 35 weight percent water, more preferably at least about 40 weight percent water. The specified amount of water ensures proper dissolution of the matrix-forming polymer, resulting in a homogeneous solution.

Preferably, the matrix polymer solution contains at least about 40 weight percent matrix polymer, more preferably at least about 45 weight percent matrix polymer. It has been found that the specified amount of matrix-forming polymer provides a more stable aerosol-generating solution.

The matrix-forming polymer may be a single polymer or a combination of two or more polymers, where one or more polymers may form a cross-linked matrix through an ionotropic gelation mechanism in a solution of multivalent cross-linking cations. Cross-linking of the matrix-forming polymer is achieved by the interaction of the polymer with multivalent cations in the cross-linking solution, which results in the formation of salt bridges for cross-linking of the polymer molecules.

Suitable matrix-forming polymers are known to those skilled in the art. Preferably, the matrix-forming polymer contains one or more polysaccharides, such as alginate or pectin, or a combination thereof. Particularly preferably, the matrix-forming polymer is an alginate. Polysaccharides are particularly suitable for use in the present invention because they can be made water insoluble and thermally stable due to cross-linking and have no taste. Thus, there is no undesirable effect on the organoleptic properties of the aerosol obtained from the aerosol generating element.

Alternative matrix-forming polymers suitable for use in the methods of the invention include, but are not limited to, chitosan, fibrin, collagen, gelatin, hyaluronic acid, dextran, and combinations thereof.

Alternative matrix-forming polymers suitable for use in the methods of the invention may be formed from one or more of the following monomers and polymers: hydroxyethyl methacrylate (HEMA), N-(2-hydroxypropyl) methacrylate (HPMA), N-vinyl-2-pyrrolidone (NVP ), N-isopropylacrylamide (NIPAMM), vinyl acetate (VAc), acrylic acid (AA), methacrylic acid (MAA), polyethylene glycol acrylate/methacrylate (PEGA/PEGMA) and polyethylene glycol diacrylate/dimethacrylate (PEGDA/PEGDMA).

After preparing a matrix polymer solution such as described above, a plurality of components of an aerosol-generating composition are added to the matrix polymer solution to form an aerosol-generating solution. The components of the aerosol-generating composition contain at least one alkaloid or cannabinoid and a polyhydric alcohol. Preferably, the components of the aerosol generating composition further comprise an acid. These components are discussed in more detail below. The aerosol-generating solution is thus a solution containing a matrix-forming polymer as well as components of the aerosol-generating composition.

Preferably, the aerosol generating solution contains at least about 1 weight percent matrix polymer from the matrix polymer solution, more preferably at least about 1.5 weight percent matrix polymer, and more preferably at least about 2 weight percent matrix polymer.

Preferably, the aerosol generating solution contains less than about 6 weight percent matrix polymer from the matrix polymer solution, more preferably less than about 5 weight percent matrix polymer, and more preferably less than about 4 weight percent matrix polymer.

For example, the aerosol generating solution may contain from about 1 weight percent to about 6 weight percent matrix-forming polymer, or from about 1.5 weight percent to about 5 weight percent matrix-forming polymer, or from about 2 weight percent to about 4 weight percent. by weight of the matrix-forming polymer.

For example, in preferred embodiments, the aerosol generating solution may contain from about 1 weight percent to about 6 weight percent alginate, or from about 1.5 weight percent to about 5 weight percent alginate, or from about 2 weight percent to about 4 percent by weight alginate.

The components of the aerosol generating composition can be added to the matrix polymer solution individually and sequentially. In some cases, it may be desirable to control the order or sequence in which components are added to the matrix polymer solution to control the viscosity of the aerosol generating solution, as discussed in more detail below.

Alternatively, two or more components of the aerosol generating composition may be combined with each other before adding to the matrix polymer solution, wherein the combination of components of the aerosol generating composition is then added to the matrix polymer solution. All components of the aerosol generating composition may be combined before adding to the matrix polymer solution, or only some components of the aerosol generating composition may be combined with each other while others are added separately and separately to the matrix polymer solution. In this latter case, the order of addition of the components of the aerosol generating composition can still be controlled, as discussed herein.

In one preferred embodiment of the invention, the aerosol generating solution is prepared by adding a liquid nicotine formulation to a matrix polymer solution, wherein the liquid nicotine formulation contains nicotine and a polyhydric alcohol. Optionally, the liquid nicotine formulation additionally contains acid. The liquid nicotine formulation may be present in the form of a formulation such as e-liquid. If the liquid nicotine formulation is added to the matrix polymer solution, then additional nicotine or acid, or both nicotine and acid, can subsequently be added to the matrix polymer solution to produce an aerosol generating solution. In this case, the order of addition of the liquid nicotine formulation and additional nicotine and acid can be controlled as discussed above. For example, if additional acid is added to the matrix polymer solution, the acid is preferably added after the liquid nicotine formulation and any additional nicotine. Preferably, this embodiment may provide a method of introducing tobacco extract into a matrix polymer solution such that it is incorporated into the aerosol generating element.

In certain embodiments of the invention, it may be desirable to control the viscosity of the aerosol generating solution. This aspect may include controlling the viscosity of the matrix polymer solution after adding the components of the aerosol generating composition. For example, depending on the method used to produce a discrete portion of the aerosol generating solution in the next step of the method, providing the aerosol generating solution having a viscosity within a particular range may be preferred. Solutions of different viscosities are likely to require different processes and thus appropriate viscosities should be determined depending on the method used.

In those embodiments in which a discrete portion of the aerosol generating solution is produced by the gravity flow method described below, the viscosity of the solution is preferably maintained at less than about 5000 mPa.s. This ensures that the aerosol generating solution droplets form under the influence of gravity and also allows the granules to acquire a stable shape in the cross-linking solution before the solution is cross-linked to form the final shape of the aerosol generating element.

In the gravity flow method, the viscosity of the aerosol generating solution is preferably from about 100 mPas to about 4000 mPas, more preferably from about 2500 mPas to about 3000 mPas. For purposes of the present invention, the viscosity of the aerosol generating solution can be measured using a torsion rotational viscometer, such as the Fungilab Viscolead ADV(L), using the following parameters: liquid volume 10 ml, temperature 25 degrees Celsius, rotation speed 10-15 rpm. A suitable test method for measuring viscosity is described in ASTM D2983-19, “Standard Test Method for Low Temperature Viscosity of Automatic Transmission Fluids, Hydraulic Fluids and Lubricants using a Rotational Viscometer.”

In certain embodiments, to control the viscosity of the aerosol generating solution, it is preferable to control the pH of the matrix polymer solution during the addition of the components of the aerosol generating composition. This is because pH can affect the viscosity of some matrix polymer solutions. For example, in those embodiments in which the matrix-forming polymer contains alginate, it is preferable to maintain the pH of the solution greater than pH 4. This aspect is intended to prevent gelation of the alginate, which can occur at a pH less than pH 4, for example, as a result of hydrogen bonding. This gelation at low pH may cause an undesirable increase in the viscosity of the aerosol generating solution, which may make it difficult to use certain methods, such as gravity flow, to make the aerosol generating element.

In these embodiments, in which the pH of the matrix polymer solution is preferably controlled while adding components of the aerosol generating composition, the components of the aerosol generating composition are preferably added sequentially to maintain the pH above a specific pH value. For example, if the matrix-forming polymer contains alginate, the components of the aerosol-generating composition are preferably added sequentially to maintain the pH of the matrix polymer solution above pH 4, as discussed above. If the components of the aerosol generating composition contain an acid, the acid is preferably added last to maintain the pH of the matrix polymer solution at a relatively high level. Preferably, if the components of the aerosol-generating composition contain nicotine, nicotine is first added to obtain a basic pH of the matrix polymer solution, after which the remaining components of the aerosol-generating composition are added.

Alternatively or in addition, the viscosity of the aerosol generating solution can be controlled by adjusting the concentration of the solution. For example, the relative water content of the aerosol generating solution can be adjusted to control the viscosity. Preferably, the aerosol generating solution contains at least about 35 percent by weight water to maintain a suitable viscosity. Particularly preferably, the aerosol generating solution contains from about 35 weight percent to about 65 weight percent water.

According to a preferred embodiment of the present invention, there is provided a method for manufacturing an aerosol generating element, comprising the steps of: providing a solution of a matrix polymer containing the matrix-forming polymer in water; adding a plurality of components of an aerosol-generating composition to a matrix polymer solution to form an aerosol-generating solution, wherein the components of the aerosol-generating composition comprise a polyhydric alcohol, at least one alkaloid or cannabinoid, and an acid, and wherein the components of the aerosol-generating composition are added sequentially to the matrix polymer solution thereby that the acid is added after other aerosol-generating components; obtaining one or more drops of an aerosol generating solution; dripping one or more drops of the aerosol-generating solution into a solution of multivalent cations for cross-linking to cross-link the matrix-forming polymer and thereby producing an aerosol-generating element containing a continuous polymer matrix and an aerosol-generating composition containing components of the aerosol-generating composition dispersed in the continuous polymer matrix; and removing the aerosol generating element from the solution to cross-link and dry the aerosol generating element.

The method as defined makes it possible to produce an aerosol generating element comprising a continuous polymer matrix and an aerosol generating composition containing components of the aerosol generating composition dispersed in the continuous polymer matrix.

As defined above, the aerosol generating solution contains a polyhydric alcohol as one of the components of the aerosol generating composition. The polyhydric alcohol acts as an aerosol generating agent in the aerosol generating element.

Polyhydric alcohols suitable for use in the aerosol generating element include, but are not limited to, propylene glycol, triethylene glycol, 1,3-butanediol and glycerol. Preferably, in the aerosol generating element manufactured in accordance with the invention, the polyhydric alcohol is selected from the group consisting of glycerol, propylene glycol and combinations thereof. In particularly preferred embodiments, the polyhydric alcohol is glycerol.

The concentration of polyhydric alcohol in the aerosol generating solution is selected such that the level of polyhydric alcohol in the final aerosol generating element is high enough to produce an acceptable aerosol. Preferably, the aerosol generating solution contains at least about 20 weight percent polyhydric alcohol, more preferably at least about 25 weight percent polyhydric alcohol, more preferably at least about 30 weight percent polyhydric alcohol, more preferably at least about 35 percent by weight of polyhydric alcohol.

Preferably, the aerosol generating solution contains less than about 60 weight percent polyhydric alcohol, more preferably less than about 55 weight percent polyhydric alcohol, more preferably less than about 50 weight percent polyhydric alcohol, more preferably less than about 45 weight percent polyhydric alcohol alcohol

For example, the aerosol generating solution may contain from about 20 weight percent to about 60 weight percent polyhydric alcohol, or from about 25 weight percent to about 55 weight percent polyhydric alcohol, or from about 30 weight percent to about 50 weight percent polyhydric alcohol, or from about 35 percent by weight to about 45 percent by weight polyhydric alcohol.

As defined above, the aerosol-generating solution further contains at least one alkaloid or cannabinoid compound as one of the components of the aerosol-generating composition.

As used herein, when describing the invention, the term “alkaloid compound” describes any of a class of naturally occurring organic compounds that contain one or more basic nitrogen atoms. In general, the alkaloid contains at least one nitrogen atom in an amine-type structure. This or another nitrogen atom in an alkaloid compound molecule may be active as a base in acid-base reactions. Most alkaloid compounds contain one or more nitrogen atoms as part of a cyclic system, such as a heterocyclic ring. In nature, alkaloid compounds are found primarily in plants and, in particular, they are particularly abundant in certain families of flowering plants. However, some alkaloid compounds are present in some animal and fungal species. In the context of the present invention, the term "alkaloid compounds" is used to describe both naturally occurring alkaloid compounds and synthetically produced alkaloid compounds.

Preferably, the alkaloid is selected from the group consisting of nicotine, anatabine, and combinations thereof.

As used herein, when describing the invention, the term “cannabinoid compound” describes any of a class of naturally occurring compounds that are present in parts of the cannabis plant—namely, the species Cannabis sativa , Cannabis indica , and Cannabis ruderalis . Cannabinoid compounds are present in particularly high concentrations in the female flower heads. Cannabinoid compounds found naturally in the cannabis plant include tetrahydrocannabinol (THC) and cannabidiol (CBD). In the context of the present invention, the term “cannabinoid compounds” is used to describe both naturally occurring cannabinoid compounds and synthetically produced cannabinoid compounds.

Preferably, the components of the aerosol-generating composition contain a cannabinoid compound selected from the group consisting of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), simple cannabigerol monomethyl ether (MCBG), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT) ) and their combinations.

In general, the content of the alkaloid compound or cannabinoid compound in the aerosol generating solution can be selected such that the aerosol generating element contains up to about 10 percent by weight of the alkaloid compound or cannabinoid compound, or both. The content of the alkaloid compound or cannabinoid compound, or both, in the aerosol generating element may be increased or adjusted to optimize delivery of the alkaloid compound or cannabinoid compound, or both, in aerosol form to the consumer. Compared to existing aerosol-generating substrates that are based on the use of plant material, this aspect may advantageously allow the content of an alkaloid compound or a cannabinoid compound, or both, to be increased per unit volume of substrate or per unit mass of substrate, which may be desirable from the point of view production.

Preferably, the aerosol-generating solution contains at least about 0.5 percent by weight of an alkaloid compound, a cannabinoid compound, or both. Thus, the aerosol generating solution preferably contains at least about 0.5 percent by weight of an alkaloid compound, or at least 0.5 percent by weight of a cannabinoid compound, or at least about 0.5 percent by weight of a combination of an alkaloid compound and a cannabinoid compound .

More preferably, the aerosol generating solution contains at least about 1 percent by weight of an alkaloid compound or a cannabinoid compound, or both, more preferably at least about 2 percent by weight of an alkaloid compound or a cannabinoid compound, or both. The aerosol generating solution preferably contains less than about 10 percent by weight of an alkaloid compound or a cannabinoid compound, or both, more preferably less than about 8 percent by weight of an alkaloid compound or a cannabinoid compound, or both, more preferably less than about 6 percent by weight of the alkaloid compound or cannabinoid compound, or both.

For example, the aerosol-generating solution may contain from about 0.5 percent by weight to about 10 percent by weight of an alkaloid compound or a cannabinoid compound, or both, or from about 1 percent by weight to about 8 percent by weight of an alkaloid compound or a cannabinoid compound , or both, or from about 2 percent by weight to about 6 percent by weight of an alkaloid compound or a cannabinoid compound, or both.

In some embodiments, the components of the aerosol-generating composition comprise one or more of a cannabinoid and an alkaloid compound containing nicotine or anatabine. In some preferred embodiments, the aerosol generating solution contains nicotine.

As used herein, when describing the invention, the term “nicotine” is used to describe nicotine, nicotine base or nicotine salt. In those embodiments in which the components of the aerosol-generating composition contain nicotine base or nicotine salt, the amounts of nicotine provided herein correspond to the amount of nicotine free base or the amount of protonated nicotine, respectively.

The components of the aerosol-generating composition may contain natural nicotine or synthetic nicotine.

The components of the aerosol-generating composition may contain one or more monobasic nicotine salts.

As used herein in describing the invention, the term “nicotine monobasic salt” is used to describe a salt of nicotine and a monobasic acid.

Preferably, the aerosol generating solution contains at least about 0.5 percent by weight nicotine. More preferably, the aerosol generating solution contains at least about 1 percent by weight nicotine. Even more preferably, the aerosol generating solution contains at least about 2 percent by weight nicotine. In addition or alternatively, the aerosol generating solution preferably contains less than about 10 percent by weight nicotine. More preferably, the aerosol generating solution contains less than about 8 percent by weight nicotine. Even more preferably, the aerosol generating solution contains less than about 6 percent by weight nicotine. For example, the aerosol generating solution may contain from about 0.5 weight percent to about 10 weight percent nicotine, or from about 1 weight percent to about 8 weight percent nicotine, or from about 2 weight percent to about 6 weight percent nicotine

Preferably, the amount of nicotine in the aerosol generating solution is adjusted to provide an aerosol generating element that contains at least about 0.5 milligrams of nicotine, more preferably at least about 1 milligram of nicotine, more preferably at least 1.5 milligrams of nicotine, more preferably at least about 2 milligrams of nicotine, and most preferably at least about 2.5 milligrams of nicotine.

The aerosol generating element may contain up to about 6 milligrams of nicotine. Preferably, the amount of nicotine in the aerosol generating solution is thus adjusted to provide an aerosol generating element containing about 6 milligrams of nicotine or less, more preferably about 5 milligrams of nicotine or less, more preferably about 4 milligrams of nicotine or less, more preferably about 3. 5 milligrams of nicotine or less, and most preferably about 3 milligrams of nicotine or less.

In some preferred embodiments, the components of the aerosol-generating composition contain a cannabinoid compound. Preferably, the cannabinoid compound is selected from CBD and THC. More preferably, the cannabinoid compound is CBD.

The aerosol generating solution may contain up to about 10 percent by weight CBD. Preferably, the aerosol generating solution contains at least about 0.5 weight percent CBD, more preferably at least about 1 weight percent CBD, more preferably at least about 2 weight percent CBD. Preferably, the aerosol generating solution contains less than about 8 percent by weight CBD, more preferably less than about 6 percent by weight CBD.

For example, the aerosol generating solution may contain from about 0.5 weight percent to about 10 weight percent CBD, more preferably from about 1 weight percent to about 8 weight percent CBD, even more preferably from about 2 weight percent to about 6 percent by weight CBD.

As described above, in preferred embodiments of the invention, the components of the aerosol generating composition further comprise an acid.

More preferably, the components of the aerosol generating composition contain one or more organic acids. Even more preferably, the components of the aerosol generating composition contain one or more carboxylic acids.

Carboxylic acids suitable for use in the aerosol generating composition in the aerosol generating elements in accordance with the present invention include, but are not limited to: 2-ethylbutyric acid, acetic acid, adipic acid, benzoic acid, butyric acid, cinnamic acid, cycloheptanecarboxylic acid, fumaric acid, glycolic acid, hexanoic acid, lactic acid, levulinic acid, malic acid, myristic acid, octanoic acid, oxalic acid, propanoic acid, grape acid, succinic acid and undecanoic acid.

In especially preferred embodiments, the acid is lactic acid or levulinic acid or benzoic acid or levulinic acid or fumaric acid or acetic acid. Most preferably, the acid is lactic acid. The inclusion of acid is particularly preferred in those embodiments in which components of the aerosol-generating composition contain nicotine, since it has been found that in the presence of acid, dissolved particles can be stabilized in the aerosol-generating solution, as is the case for nicotine and other plant extracts. Without wishing to be bound by theory, it is believed that the acid may react with the nicotine molecule, causing the protonated nicotine to be stabilized. Since protonated nicotine is non-volatile, it passes more easily into the liquid or dispersed phase than into the vapor phase of the aerosol produced by heating the aerosol generating element. In this way, nicotine losses during production of the aerosol generating element can be minimized, and increased amounts of nicotine can be preferably delivered to the consumer in a more easily controlled manner.

Preferably, the aerosol generating solution contains at least about 0.5 percent by weight acid. More preferably, the aerosol generating solution contains at least about 1 percent by weight acid. Even more preferably, the aerosol generating solution contains at least about 2 percent by weight acid. In addition or alternatively, the aerosol generating solution preferably contains less than about 10 percent by weight acid. More preferably, the aerosol generating solution contains less than about 8 percent by weight acid. Even more preferably, the aerosol generating solution contains less than about 6 percent by weight acid.

For example, the aerosol generating solution may contain from about 0.5 weight percent to about 10 weight percent acid, or from about 1 weight percent to about 8 weight percent acid, or from about 2 weight percent to about 6 weight percent acids.

Preferably, if the aerosol generating solution contains nicotine, the acid to nicotine molar ratio is from about 0.5:1 to about 2:1, more preferably from about 0.75:1 to about 1.5:1, most preferably about 1 :1.

If a polybasic acid, such as a polycarboxylic acid, is used, it may be preferable to provide a molar ratio of acid groups to nicotine of from about 0.5:1 to about 2:1, more preferably from about 0.75:1 to about 1.5: 1, most preferably about 1:1. The use of a polybasic acid thus allows the use of a smaller mass amount of acid and at the same time provide the same level of nicotine protonation.

The aerosol-generating composition components included in the aerosol-generating solution may optionally further contain a flavoring agent. The flavoring agent may be present in liquid form or in solid form. Optionally, the flavor may be provided in microencapsulated form from which the flavor is released upon heating. Preferably, the amount of flavor in the aerosol generating solution is adjusted to provide the desired amount of flavor in the aerosol generating element. Preferably, the flavor content of the aerosol generating element is from about 0.05 weight percent to about 1 weight percent, more preferably from about 0.1 weight percent to about 0.5 weight percent.

Flavoring agents suitable for use as components of the aerosol generating composition of the present invention include, but are not limited to, tobacco, menthol, mint such as peppermint or spearmint, cocoa, licorice, fruits (such as citrus fruits), gamma octalactone, vanillin, spices (such as cinnamon), methyl salicylate, linalool, eugenol, eucalyptol, bergamot oil, eugenol oil, geranium oil, lemon oil, ginger oil and tobacco flavoring.

Optionally, the aerosol generating solution may further comprise a plurality of electroabsorbing particles. Electroabsorbing particles are conductive particles that have the ability to convert electromagnetic radiation energy into heat. When electroabsorbing particles are placed in an alternating electromagnetic field, eddy currents are induced in them and hysteresis losses occur, which leads to heating of the electroabsorbing particles. Since the electroabsorbing particles are in thermal contact or in close proximity to provide thermal contact with the aerosol generating composition in the aerosol generating element, the aerosol generating composition is heated by the electroabsorbing particles, resulting in an aerosol.

Incorporation of electroabsorbing particles into the aerosol-generating solution thus provides an aerosol-generating element that is amenable to induction heating. If the aerosol generating element is used in a device comprising an induction heater, the varying electromagnetic fields generated by one or more induction coils of the induction heating device heat the electroabsorbing particles, which then transfer heat to the surrounding aerosol generating composition in the aerosol generating element, mainly through a mechanism thermal conductivity.

The electroabsorbing particles can be made from any material that can be heated by an induction source to a temperature sufficient to produce an aerosol from the aerosol-generating composition. Preferred electroabsorbent particles contain metal or carbon. Preferred electroabsorbing particles may comprise or be composed of a ferromagnetic material, for example a ferromagnetic alloy, ferritic iron or ferromagnetic steel or stainless steel. Suitable electroabsorbent particles may be, or contain, aluminum. Preferred electroabsorbing particles can be heated to temperatures greater than 250 degrees Celsius. Suitable electroabsorbent particles may comprise a non-metallic core with a metal layer located on top of the non-metallic core, for example, with metal tracks formed on the surface of the ceramic core. The electroabsorbent particles may have a protective outer layer, such as a protective ceramic layer or a protective glass layer, in which the electroabsorbent particle is encapsulated. The electroabsorbent particles may comprise a protective coating made of glass, ceramic, or inert metal deposited over a core of electroabsorbent material.

The electroabsorbing particles can have an average size of up to about 60 micrometers. For example, the electroabsorbent particles may have an average size of about 50 micrometers or less, or about 40 micrometers or less, or about 35 micrometers or less.

Typically, in the aerosol generating solution for use in the methods of the present invention, the electroabsorbent particles have an average size of at least about 1 micrometer, or at least about 2 micrometers, or at least about 5 micrometers, or at least about 10 micrometers .

For example, the electroabsorbing particles in the aerosol generating solution may have an average size of from about 1 micrometer to about 60 micrometers, or from about 2 micrometers to about 50 micrometers, or from about 5 micrometers to about 40 micrometers, or from about 10 micrometers to about 35 micrometers.

Optionally, a solid filler may be added to the aerosol generating solution. The inclusion of solid filler may advantageously improve the physical properties of the final aerosol generating element. The solid filler can also be used to control the properties of the aerosol generating solution during the process of producing a discrete portion of the aerosol generating solution. Suitable solid fillers will be known to those skilled in the art.

For example, in certain embodiments of the present invention, the aerosol generating solution further comprises particles of plant material obtained by grinding, grinding or grinding the plant material. By way of example, the aerosol-generating solution may further comprise tea particles, coffee particles, hemp particles, clove particles, eucalyptus particles, star anise particles, or ginger particles. In addition or alternatively, the aerosol generating solution may further comprise tobacco particles obtained by grinding, grinding or pulverizing one or more of the tobacco leaf blades and tobacco stems. The inventors of the present invention have discovered that by preferably incorporating said plant particles into the aerosol generating element, it becomes possible to produce an aerosol that provides novel sensory sensations. This aerosol provides a unique taste and can provide an increased level of fullness in the mouth.

In those embodiments in which the aerosol generating solution contains plant particles, the amount of plant particles in the aerosol generating solution is adjusted to provide the desired content of plant particles in the aerosol generating element and the desired amount of flavoring agents in the resulting aerosol. The aerosol generating element may contain up to about 40 percent by weight of plant particles. Preferably, the aerosol generating element contains about 35 percent by weight of plant particles or less. More preferably, the aerosol generating element contains about 30 percent by weight of plant particles or less. Even more preferably, the aerosol generating element contains about 25 percent by weight of plant particles or less.

In some embodiments, the aerosol generating element comprises at least about 1 percent by weight of plant particles. Preferably, the aerosol generating element contains at least about 2 percent by weight of plant particles. More preferably, the aerosol generating element contains at least about 5 percent by weight of plant particles. Even more preferably, the aerosol generating element contains at least about 10 percent by weight of plant particles.

For example, the aerosol generating substrate may contain from about 1 weight percent to about 40 weight percent plant particles, more preferably from about 2 weight percent to about 35 weight percent plant particles, more preferably from about 5 weight percent to about 30 percent by weight of the plant particles, and most preferably from about 10 percent by weight to about 25 percent by weight of the plant particles.

Providing the amount of plant particles within the specified range allows for the desired flavor of the plant particles to be achieved without altering the consistency of the aerosol generating solution to such an extent as to adversely affect the processing of the aerosol generating solution to make the aerosol generating element.

In those embodiments in which the aerosol generating solution contains plant particles, the plant particles may have an average diameter of up to about 60 micrometers. Preferably, the plant particles have an average size of about 50 micrometers or less, more preferably about 40 micrometers or less, and most preferably about 35 micrometers or less.

Typically, in the aerosol generating solution for use in the methods of the present invention, the plant particles have an average size of at least about 1 micrometer, more preferably at least about 2 micrometers, more preferably at least about 5 micrometers, and most preferably at least at least about 10 micrometers.

For example, the plant particles in the aerosol generating solution may have an average size of from about 1 micrometer to about 60 micrometers, more preferably from about 2 micrometers to about 50 micrometers, more preferably from about 5 micrometers to about 40 micrometers, most preferably from about 10 micrometers to approximately 35 micrometers.

In the next step of the method according to the invention, after obtaining the aerosol-generating solution, a discrete portion of the aerosol-generating solution is obtained. A "discrete portion" of a solution corresponds to a specific volume of solution that is typically processed to provide an aerosol generating element having a specific geometric shape and size. The discrete portion of the aerosol generating solution can be formed into a variety of geometric shapes depending on the desired shape of the aerosol generating element. For example, the aerosol-generating solution may be shaped into spherical or cylindrical shapes to produce droplets, granules, or threads of material. Alternatively, the aerosol-generating solution can be processed into a sheet, cut into strips or layers, or drawn into elongated threads or yarns.

In particularly preferred embodiments of the invention, the step of producing a discrete portion of the aerosol generating solution includes forming a droplet. Preferably, a droplet of the aerosol-generating solution is produced by a dripping method in which the aerosol-generating solution is dropped dropwise from an extrusion orifice or nozzle. The nozzle may optionally be connected to a pump. Particularly preferably, a droplet of the aerosol generating solution is produced by a gravity flow method, in which each droplet flows from the extrusion nozzle only under the influence of gravity. Alternatively, the extrusion nozzle may vibrate to facilitate drop formation and release.

In preferred embodiments of the invention in which the droplet is produced by a dripping method, the diameter of the droplet can be adjusted by adjusting the diameter of the extrusion nozzle or the viscosity of the aerosol generating solution, or both. Preferably, for producing an aerosol generating element having an appropriate size for use in an aerosol generating article or system, an extrusion nozzle having an orifice with a diameter of from about 0.5 mm to about 6 mm is used.

Typically, in these embodiments, upon release from the extrusion nozzle, the drop falls by gravity into the cross-linking solution. Preferably, the droplet is formed at a height of at least 0.1 meter above the cross-linking solution. This minimum drop height is preferred, for example, if a spherical droplet is desired, since it ensures that the droplet falls over a sufficient distance to produce a spherical shape. Preferably, the droplet is produced at a height of less than 0.6 meters above the cross-linking solution, thereby minimizing any deformation of the droplet before it enters the cross-linking solution.

In certain embodiments, the dripping method may be combined with a jet disruption method, which breaks up the droplet or stream of aerosol-generating solution after it exits the nozzle to produce smaller droplets. For example, a jet cutting device such as a rotating disk may be provided below the extrusion nozzle to break up the flow of the aerosol generating solution to produce droplets. A method of this type is particularly suitable if aerosol generating elements having a relatively small diameter are required.

Alternatively, an electrostatic extrusion process may be used, in which the stream of aerosol-generating solution exiting the extrusion nozzle is disrupted by electrostatic charge. As with the jet cutting method, electrostatic extrusion may be particularly suitable for producing aerosol generating elements having a relatively small diameter. As a further alternative, the flow of the aerosol-generating solution may be disrupted by vibration means provided at or adjacent to the nozzle.

As discussed above, the desired viscosity of the aerosol generating solution depends to a certain extent on the chosen method of producing a discrete portion of the aerosol generating solution. Suitable viscosity ranges for the gravity flow method were specified. Jet cutting may be suitable for aerosol-generating solutions with relatively high viscosity, for example greater than 200 mPa s. In contrast, electrostatic extrusion may be more suitable for aerosol-generating solutions with low viscosity, for example, less than 200 mPa.s.

Once prepared, a discrete portion of the aerosol generating solution, which is preferably in the form of a droplet, is added to the solution of multivalent cations for cross-linking. This results in cross-linking of the matrix-forming polymer, thereby forming a solid continuous polymer matrix such as described above. The cross-linking solution preferably contains a multivalent metal salt solution, such as a metal chloride solution. Preferred multivalent cations include calcium, iron, aluminum, manganese, copper, zinc or lanthanum. A particularly preferred salt is calcium chloride.

In certain preferred embodiments of the invention in which the aerosol generating solution contains an acid, the calcium salt provided in the cross-linking solution may preferably be a salt of the same acid. For example, in those embodiments in which the aerosol generating solution contains lactic acid, the cross-linking solution may preferably contain calcium lactate.

If the aerosol-generating solution contains nicotine, the acid in the aerosol-generating solution combines with the nicotine to form a nicotine salt. The use of a calcium salt corresponding to the acid in the aerosol generating solution thus provides the same salt in the crosslinking solution as in the aerosol generating solution. This in turn preferably limits the diffusion of nicotine salts from the aerosol generating solution into the crosslinking solution during the crosslinking step. Thus, an increased concentration of nicotine salt can be retained in the aerosol generating element. In addition, it is possible to reduce the amount of nicotine and acid that may be waste during the manufacture of the aerosol generating element.

Preferably, the cross-linking solution contains from about 0.5 percent by weight to about 10 percent by weight of the multivalent metal salt in the cross-linking solution.

Preferably, the cross-linking step is carried out without heating, for example at room temperature (22 degrees Celsius). The period of time that the discrete portion of the aerosol generating solution is left in the cross-linking solution can be selected depending on the desired degree of cross-linking in the aerosol generating element. In certain preferred embodiments, a discrete portion of the aerosol generating solution is left in the cross-linking solution for a period of from about 10 minutes to about 30 minutes.

Preferably, the cross-linking solution further contains a polyhydric alcohol that is the same as the polyhydric alcohol selected as a component of the aerosol generating composition. It has been found that the inclusion of a polyhydric alcohol in the cross-linking solution limits the diffusion of the polyhydric alcohol from the aerosol generating solution into the cross-linking solution during the cross-linking step. This advantageously allows a higher concentration of polyhydric alcohol to be maintained in the aerosol generating element than was previously available. In addition, reduced diffusion of the polyhydric alcohol into the cross-linking solution may advantageously help maintain the geometric shape of the aerosol generating element in the cross-linking process.

Preferably, the crosslinking solution contains from about 20 weight percent to about 60 weight percent polyhydric alcohol, more preferably from about 30 weight percent to about 50 weight percent polyhydric alcohol.

As discussed above, the polyhydric alcohol in the cross-linking solution is selected to match the polyhydric alcohol in the aerosol generating solution. In preferred embodiments, the polyhydric alcohol is glycerol.

In particularly preferred embodiments of the present invention, the concentration of the polyhydric alcohol in the cross-linking solution is adjusted depending on the concentration of said polyhydric alcohol in the aerosol generating solution. In particular, it is desirable that the concentration of the polyhydric alcohol in the cross-linking solution be as similar as possible to the concentration of the same polyhydric alcohol in the aerosol generating solution. This aspect has been found to optimize the beneficial effects of including a polyhydric alcohol in the cross-linking solution, such as those described above.

Preferably, the concentration of the polyhydric alcohol in the cross-linking solution differs by no more than about 20 percent from the concentration of the same polyhydric alcohol in the aerosol generating solution, more preferably by no more than about 15 percent, and more preferably by no more than about 10 percent. In particularly preferred embodiments, the concentration of the polyhydric alcohol in the cross-linking solution is approximately equal to the concentration of the same polyhydric alcohol in the aerosol generating solution.

After cross-linking, remove the manufactured aerosol generating element from the cross-linking solution, for example, using a sieve or similar device. The aerosol generating element is preferably washed to remove the cross-linking solution from the surface. The aerosol generating element is then dried to reduce the water content to the desired level.

Preferably, drying of the aerosol generating element is carried out to reduce the water content of the aerosol generating element to a level of less than about 20 percent by weight, more preferably less than about 15 percent by weight. The specified water content is preferable for the aerosol generating element and allows the aerosol to be produced in an efficient manner by heating the aerosol generating element during use.

Preferably, drying of the aerosol generating element is carried out to reduce the water activity (a _w ) in the aerosol generating element to a level of less than about 0.7, more preferably less than about 0.5. This advantageously reduces the likelihood of bacterial and fungal proliferation in the aerosol generating element.

As used herein, when describing the present invention, the term “water activity” refers to the ratio of the partial pressure of water vapor at equilibrium above an aerosol generating element to the saturation pressure of water vapor at equilibrium above pure water at the same temperature. Thus, water activity is a dimensionless quantity ranging from 0, which corresponds to a completely anhydrous substance, to 1, which corresponds to pure demineralized water. Methods for measuring water activity in an aerosol generating element in accordance with the present invention are described in 2017 ISO 18787 (Foodstuffs - Determination of water activity). Preferably, a dew point measurement principle such as that described in ISO 18787 is used.

Drying of the aerosol generating element can be accomplished using any suitable means, including, for example, a dryer in which the aerosol generating element is heated. The duration and temperature of the drying stage can be adjusted depending on the apparatus used and to achieve the desired water content. For example, the aerosol generating element can be dried at 25 degrees Celsius for 12 hours or at 100 degrees Celsius for 3 hours. Drying may not necessarily be carried out in a vacuum.

The method of the present invention may further include the step of coating the aerosol generating element to provide an outer coating layer on the aerosol generating element. The coating step can be carried out before the drying step or after the drying step. After the coating step, an optional drying step can be carried out.

Providing a coating layer on the aerosol generating element may be desirable for a variety of different reasons. For example, the coating layer may advantageously limit the penetration of oxygen or water vapor into the aerosol generating element, which may help extend the shelf life of the aerosol generating element. Alternatively or in addition, the coating layer may help protect the structural integrity of the aerosol generating element or provide improved smoothness of the aerosol generating element. In certain embodiments, a relatively frangible coating layer may be added to the aerosol generating element that is designed to be broken by the consumer prior to use. Thus, a coating layer of this type can provide the user with tactile and audible information regarding the activation of the aerosol generating element. Alternatively or in addition, providing a coating layer on the aerosol generating element can be used to control the color of the aerosol generating element, for example, to provide visual information about a property of the aerosol generating element, such as taste or nicotine content.

Suitable types of coating material may be known to one skilled in the art. For example, a coating layer based on a water-soluble film-forming agent, such as HPMC or shellac, can be applied to the aerosol generating element. These film-forming agents can firmly adhere to the surface of the aerosol generating element. In a further example, a sodium alginate coating layer can be added which can cross-link any remaining calcium ions on the surface of the aerosol generating element to form a thin film of calcium alginate.

The coating layer can be applied to the outer surface of the aerosol generating element by a variety of coating methods. Suitable devices and methods may be known to one skilled in the art.

The method of the present invention has been described with respect to the manufacture of a separate aerosol generating element. However, those skilled in the art will appreciate that the present invention also includes methods for making an array of aerosol generating elements. The described method can be easily adapted by one skilled in the art to produce an array of aerosol generating elements, for example, in a batch process in which a collection of discrete portions of an aerosol generating solution are prepared and simultaneously added to the cross-linking solution, or in a continuous process in which the aerosol generating solution is continuously produced. discrete portions of the aerosol generating solution and added to the cross-linking solution.

The method according to the present invention makes it possible to obtain an aerosol generating element having a characteristic structure. As defined above, the aerosol generating element comprises a continuous polymer matrix and an aerosol generating composition dispersed within the continuous polymer matrix, the aerosol generating composition being contained within the continuous polymer matrix.

Without wishing to be bound by theory, it is believed that in the aerosol generating element in accordance with the present invention, a three-dimensional structure of the polymer matrix is formed by cross-linking, and the aerosol generating composition is held in a continuous structure of the polymer matrix. This aspect in particular differs from existing core/shell structures, in which the contents of the core are released when the shell breaks down.

Compounds that can be included in the aerosol generating element and preferred amounts of said compounds are described above with respect to the method of the present invention.

Preferably, the aerosol generating composition dispersed in the solid structure of the continuous matrix constitutes at least about 70 percent by weight of the total mass of the aerosol generating element, or even at least about 75 percent by weight of the total mass of the aerosol generating element, or at least about 80 percent by mass of the total mass of the aerosol generating element.

More preferably, the aerosol generating composition dispersed in the solid continuous polymer matrix constitutes at least 82 percent by weight of the total mass of the aerosol generating element. Even more preferably, the aerosol generating composition dispersed in the continuous polymer matrix constitutes at least about 84 percent by weight of the total mass of the aerosol generating element.

In especially preferred embodiments, the aerosol generating composition dispersed in the continuous polymer matrix constitutes at least about 86 percent by weight of the total mass of the aerosol generating element. More preferably, the aerosol generating composition dispersed in the continuous polymer matrix constitutes at least about 88 percent by weight of the total mass of the aerosol generating element. Even more preferably, the aerosol generating composition dispersed in the continuous polymer matrix constitutes at least about 90 percent by weight of the total mass of the aerosol generating element.

Most preferably, the aerosol generating composition dispersed in the continuous polymer matrix constitutes at least about 92 weight percent of the total mass of the aerosol generating element, or at least about 93 weight percent of the total mass of the aerosol generating element, or at least about 94 percent by weight of the total mass of the aerosol generating element, or at least about 95 percent by weight of the total mass of the aerosol generating element.

In aerosol generating elements in which the aerosol generating composition constitutes a certain proportion of the total mass of the aerosol generating element within the ranges described above, it is preferably possible to minimize the amount of heat supplied to the aerosol generating element during use, which is used to increase the temperature of the encapsulating material. Thus, it becomes possible to more efficiently utilize the heat supplied to the aerosol generating element, with the result that the majority of said heat is effectively used to release the components of the aerosol generating composition from the continuous polymer matrix and produce an aerosol.

As defined above, the aerosol generating element in accordance with the invention contains a polyhydric alcohol as a component of the aerosol generating composition dispersed in a continuous polymer matrix. The aerosol generating element of the present invention preferably contains at least about 30 weight percent polyhydric alcohol, more preferably at least about 40 weight percent polyhydric alcohol, more preferably at least about 50 weight percent polyhydric alcohol, more preferably at least about 60 weight percent polyhydric alcohol, more preferably at least about 70 weight percent polyhydric alcohol, based on the total weight of the aerosol generating element.

Typically, in the aerosol generating element of the invention, the polyhydric alcohol content of the aerosol generating composition is about 95 percent by weight or less, based on the total weight of the aerosol generating element.

As defined above, in the aerosol generating element in accordance with the present invention, a continuous polymer matrix is formed by a matrix-forming polymer after cross-linking it. Preferably, the aerosol generating element contains at least about 2 weight percent matrix polymer, more preferably at least about 2.5 weight percent matrix polymer, and more preferably at least about 3 weight percent matrix polymer. Preferably, the aerosol generating element contains less than about 6 weight percent matrix polymer, more preferably less than about 5 weight percent matrix polymer, more preferably less than about 4.5 weight percent matrix polymer. For example, the aerosol generating element may contain from about 2 weight percent to about 6 weight percent matrix-forming polymer, or from about 2.5 weight percent to about 5 weight percent matrix-forming polymer, or from about 3 weight percent to about 4. 5 percent by weight matrix-forming polymer.

As defined above, in the aerosol generating element in accordance with the present invention, the aerosol generating composition dispersed in a continuous polymer matrix contains at least one alkaloid or cannabinoid compound. In some embodiments, the aerosol-generating composition dispersed in a continuous polymer matrix contains both an alkaloid compound and a cannabinoid compound.

In general, the aerosol generating element may contain up to about 10 percent by weight of an alkaloid compound or a cannabinoid compound, or both. When considering the applications of the aerosol generating element according to the invention as a substrate in an aerosol generating article, they are preferred because the content of the alkaloid compound or cannabinoid compound, or both of these compounds in the element can be increased or adjusted to optimize the delivery of the alkaloid compound or cannabinoid compound, or both of these compounds in the form of an aerosol to the consumer. Compared to existing aerosol-generating substrates that are based on the use of plant material, this aspect may advantageously allow the content of an alkaloid compound or a cannabinoid compound, or both, to be increased per unit volume of the substrate (element or elements) or per unit mass of the substrate (element or elements). elements), which may be desirable from a production point of view.

Preferably, the content of at least one alkaloid or cannabinoid compound in the aerosol generating composition dispersed in the continuous polymer matrix is at least 0.5 percent by weight of the total mass of the aerosol generating element. Thus, the aerosol generating element preferably contains at least about 0.5 percent by weight of an alkaloid compound, or at least 0.5 percent by weight of a cannabinoid compound, or at least about 0.5 percent by weight of a combination of an alkaloid compound and a cannabinoid compound .

More preferably, the aerosol generating element contains at least about 1 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Even more preferably, the aerosol generating element contains at least about 2 percent by weight of an alkaloid compound or a cannabinoid compound, or both.

The aerosol generating element preferably contains less than about 8 percent by weight of an alkaloid compound or a cannabinoid compound, or both. More preferably, the aerosol generating element contains less than about 6 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Even more preferably, the aerosol generating element contains less than about 5 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Most preferably, the aerosol generating element contains less than about 4 percent by weight of an alkaloid compound or a cannabinoid compound, or both.

In some embodiments, the aerosol generating element contains from about 0.5 weight percent to about 10 weight percent an alkaloid compound or a cannabinoid compound, or both, more preferably from about 1 weight percent to about 10 weight percent an alkaloid compound, or a cannabinoid compound, or both, even more preferably from about 2 percent by weight to about 10 percent by weight of an alkaloid compound or a cannabinoid compound, or both.

As described above with respect to the method of the present invention, in some preferred embodiments, the aerosol generating element contains nicotine.

In general, the aerosol generating element may contain up to about 10 percent by weight nicotine. When considering the use of the aerosol generating element according to the invention as a substrate in an aerosol generating article, they are preferred because the nicotine content of the aerosol generating element can be increased or adjusted to optimize the delivery of nicotine as an aerosol to the consumer. Compared to existing aerosol-generating substrates that are based on the use of plant tobacco, this aspect may advantageously allow for an increase in nicotine content per unit volume of the substrate (element or elements) or per unit mass of the substrate (element or elements), which may be desirable from the point of view of production.

Preferably, the aerosol generating element contains at least about 0.5 percent by weight nicotine. More preferably, the aerosol generating element contains at least about 1 percent by weight nicotine. Even more preferably, the aerosol generating element contains at least about 2 percent by weight nicotine.

The aerosol generating element preferably contains about 8 percent by weight nicotine or less. More preferably, the aerosol generating element contains about 6 percent by weight nicotine or less. Even more preferably, the aerosol generating element contains about 5 percent by weight nicotine or less. Most preferably, the aerosol generating element contains about 4 percent by weight nicotine or less.

In some embodiments, the aerosol generating element contains from about 0.5 weight percent to about 10 weight percent nicotine, more preferably from about 1 weight percent to about 10 weight percent nicotine, even more preferably from about 2 weight percent to approximately 10 percent by weight nicotine.

Preferably, the aerosol generating element contains at least about 0.5 milligrams of nicotine. More preferably, the aerosol generating element contains at least about 1 milligram of nicotine. Even more preferably, the aerosol generating element contains at least about 1.5 milligrams of nicotine. In especially preferred embodiments, the aerosol generating element contains at least about 2 milligrams of nicotine, and most preferably at least about 2.5 milligrams of nicotine.

The aerosol generating element may contain up to about 6 milligrams of nicotine. Preferably, the aerosol generating element contains about 5 milligrams of nicotine or less. More preferably, the aerosol generating element contains about 4.5 milligrams of nicotine or less. Even more preferably, the aerosol generating element contains about 4 milligrams of nicotine or less. In especially preferred embodiments, the aerosol generating element contains about 3.5 milligrams of nicotine or less, and most preferably about 3 milligrams of nicotine or less.

In some preferred embodiments, the aerosol generating composition dispersed in a continuous polymer matrix in the aerosol generating element contains a cannabinoid compound. Preferably, the cannabinoid compound is selected from CBD and THC. More preferably, the cannabinoid compound is CBD.

The aerosol generating element may contain up to about 10 percent by weight CBD. Preferably, the aerosol generating element contains at least about 0.5 percent by weight CBD. More preferably, the aerosol generating element contains at least about 1 percent by weight CBD. Even more preferably, the aerosol generating element contains at least about 2 percent by weight CBD.

The aerosol generating element preferably contains about 6 percent by weight CBD or less. More preferably, the aerosol generating element contains about 5 percent by weight CBD or less. Even more preferably, the aerosol generating element contains about 4 percent by weight CBD or less.

In some embodiments, the aerosol generating element contains from about 0.5 weight percent to about 10 weight percent CBD, more preferably from about 1 weight percent to about 10 weight percent CBD, even more preferably from about 2 weight percent to approximately 10 percent by weight CBD.

The aerosol generating element in accordance with the present invention may be an aerosol generating element substantially free of tobacco.

As used herein, when describing the invention, the term “substantially tobacco-free aerosol generating element” describes an aerosol generating element that contains less than 1 percent tobacco by weight. For example, the tobacco content of the aerosol generating element may be less than about 0.75 weight percent, less than about 0.5 weight percent, or less than about 0.25 weight percent.

The aerosol generating element may be an aerosol generating element that does not contain tobacco.

As used herein, when describing the invention, the term “tobacco-free aerosol generating element” describes an aerosol generating element in which the tobacco content is 0 percent by weight.

As described above, in some embodiments, the aerosol generating composition dispersed in a continuous polymer matrix further comprises an acid.

The aerosol generating element may contain up to about 10 percent by weight acid.

Preferably, the aerosol generating element contains at least about 0.5 percent by weight acid. More preferably, the aerosol generating element contains at least about 1 percent by weight acid. Even more preferably, the aerosol generating element contains at least about 2 percent by weight acid.

The aerosol generating element preferably contains about 8 percent by weight acid or less. More preferably, the aerosol generating element contains about 6 percent by weight acid or less. Even more preferably, the aerosol generating element contains about 5 percent by weight acid or less. Most preferably, the aerosol generating element contains about 4 percent by weight acid or less.

In some embodiments, the aerosol generating element contains from about 0.5 weight percent to about 10 weight percent acid, more preferably from about 1 weight percent to about 10 weight percent acid, even more preferably from about 2 weight percent to approximately 10 percent by weight acid.

The aerosol generating element of the present invention preferably contains about 25 percent by weight water or less.

More preferably, the aerosol generating element contains about 20 percent by weight water or less. Even more preferably, the aerosol generating element contains about 15 percent by weight water or less.

The aerosol generating element of the present invention preferably contains at least about 2.5 percent by weight water. More preferably, the aerosol generating element of the present invention preferably contains at least about 5 percent by weight water. Even more preferably, the aerosol generating element of the present invention preferably contains at least about 7.5 percent by weight water. Most preferably, the aerosol generating element of the present invention preferably contains at least about 10 percent by weight water.

In general, it has been found that the presence of some water is associated with disruption of the desired stability of the aerosol generating element. At the same time, a residual water content of 25 percent by weight or less is desirable so that an aerosol generating element that is substantially non-stick can be manufactured. In addition, by heating a low water content aerosol generating element, an aerosol with an increased concentration of a polyhydric alcohol and an alkaloid or cannabinoid compound, such as nicotine, can be provided to the consumer.

The aerosol generating element according to the invention may have an equivalent diameter of at least about 0.5 millimeters.

The term “equivalent diameter of an aerosol generating element” as used herein means the diameter of a sphere that has the same volume as the aerosol generating element. In general, the aerosol generating element can have any geometric shape, with a spherical or quasi-spherical shape, such as an egg-shaped or ellipsoidal shape, being preferred. In the case of an aerosol generating element having a spherical shape and a circular cross section, the equivalent diameter is the cross-sectional diameter of the aerosol generating element.

Preferably, the aerosol generating element has an equivalent diameter of at least about 1 millimeter. More preferably, the aerosol generating element has an equivalent diameter of at least about 2 millimeters. Even more preferably, the aerosol generating element has an equivalent diameter of at least about 3 millimeters.

The aerosol generating element according to the invention preferably has an equivalent diameter of about 8 millimeters or less. More preferably, the aerosol generating element has an equivalent diameter of about 6 millimeters or less. Even more preferably, the aerosol generating element has an equivalent diameter of about 5 millimeters or less.

In some embodiments, the aerosol generating element has an equivalent diameter of from about 0.5 millimeters to about 8 millimeters, preferably from about 1 millimeter to about 8 millimeters, more preferably from about 2 millimeters to about 8 millimeters, even more preferably from about 3 millimeters to approximately 8 millimeters.

In particularly preferred embodiments, the aerosol generating element has an equivalent diameter of about 4 millimeters or about 4.5 millimeters.

The aerosol generating elements of the present invention may have an ovality of up to about 35 percent.

The term "ovality" as used herein when describing the present invention refers to the degree of deviation from an ideal circle. Ovality is expressed as a percentage and the mathematical definition is given below.

To determine the ovality of an object, such as an aerosol generating element, the object can be viewed in a direction substantially perpendicular to the cross section of the aerosol generating element. As an example, the aerosol generating element may be positioned on a transparent platform such that the aerosol generating element is imaged by a suitable imaging device located below the platform. Dimension “ a ” is taken to be the largest outer diameter in the image of the aerosol-generating element, and dimension “ b ” is taken to be the smallest outer diameter in the image of the aerosol-generating element. The method is repeated for a total of ten aerosol-generating elements having the same composition and manufactured by the same method under the same conditions. The number average of the ten ovality measurements is recorded as the ovality for a given aerosol generating element.

Preferably, the aerosol generating element in accordance with the invention has an ovality of about 30 percent or less. More preferably, the aerosol generating element in accordance with the invention has an ovality of about 25 percent or less. Even more preferably, the aerosol generating element in accordance with the invention has an ovality of about 20 percent or less.

The aerosol generating element in accordance with the invention typically has an ovality of at least about 1 percent. Preferably, the aerosol generating element has an ovality of at least 2 percent. More preferably, the aerosol generating element has an ovality of at least 3 percent. Even more preferably, the aerosol generating element has an ovality of at least 4 percent.

In some embodiments, the aerosol generating element has an ovality of from about 1 percent to about 30 percent, more preferably from about 2 percent to about 30 percent, more preferably from about 3 percent to about 30 percent, even more preferably from about 4 percent to about 30 percent.

The aerosol generating article in accordance with the present invention may have an exposed surface area to volume ratio of up to 25 cm ^-1 .

The expression "exposed surface area to volume ratio" as used herein in describing the present invention means the ratio of the total area of the outer surface of the aerosol generating element that is open and available for heat and mass transfer to the total volume of the aerosol generating element.

Since the aerosol generating elements in accordance with the invention have a low ovality and can be approximately considered as spherical objects, the volume of the aerosol generating element in accordance with the invention can be expressed by the formula

The exposed surface area of the aerosol generating element in accordance with the invention can be estimated by the formula

The size R _eq denotes the equivalent radius of the aerosol generating element.

Preferably, the aerosol generating article has an exposed surface area to volume ratio of at least about 0.083 cm ^-1 . More preferably, the aerosol generating article has an exposed surface area to volume ratio of at least about 0.166 cm ^-1 . Even more preferably, the aerosol generating article has an open surface area to volume ratio of at least about 0.249 cm ^-1 .

The aerosol generating article preferably has an open surface area to volume ratio of about 24 cm ^-1 or less. More preferably, the aerosol generating article has an exposed surface area to volume ratio of about 20 cm ^-1 or less. Even more preferably, the aerosol generating article has an exposed surface area to volume ratio of about 16 cm ^-1 or less.

In some embodiments, the aerosol generating article has an exposed surface area to volume ratio of from about 0.083 cm ^-1 to about 24 cm ^-1 , more preferably from about 0.166 cm ^-1 to about 24 cm ^-1 , even more preferably from about 0.249 cm ^{-1 1} to about 24 cm ^-1 .

In some embodiments, the aerosol generating elements of the present invention may be coated as described above with respect to the method of the present invention.

Aerosol generating elements such as those described above may find use as an aerosol generating substrate in aerosol generating articles of the type in which the substrate is heated to release an inhalation aerosol as opposed to articles in which the substrate is burned to produce smoke.

Since the aerosol generating elements in accordance with the invention can be easily manufactured and have predetermined characteristics, therefore, discrete quantities of the aerosol generating composition can be provided in encapsulated form, and since the composition of the aerosol generating composition - in particular, in part, Concerning the content of polyhydric alcohol and alkaloid or cannabinoid compound - can be finely tuned and controlled, the aerosol generating elements in accordance with the invention are universal and can be used as substrates in a variety of configurations.

As an example, a plurality of aerosol generating elements in accordance with the invention may be provided within a cavity defined by a tubular element, whereby the outer surface of the aerosol generating elements remains open within a longitudinal air flow channel defined by the cavity. When heated, the aerosol generating elements can generate an aerosol, which is thus released into the air flow channel and can be inhaled through the tubular element into the mouth of the consumer.

Aerosol generating elements such as those described above may therefore find use in an aerosol generating system comprising one or more aerosol generating elements, or in an aerosol generating article such as described above, and in an electronically controlled aerosol generating device. A suitable aerosol generating device includes a heating element and a heating chamber configured to introduce one or more aerosol generating elements or article, causing the one or more aerosol generating elements to be heated in the heating chamber under the action of the heating element.

When heated, the aerosol generating elements in accordance with the present invention release an aerosol containing components of the aerosol generating composition, including, in particular, a polyhydric alcohol and an alkaloid or cannabinoid compound. It has been found that if the aerosol generating element in accordance with the present invention is heated to a temperature ranging from about 150 degrees Celsius to about 350 degrees Celsius, the mass of the aerosol generating element is reduced without the volume being reduced to a significant extent. In addition, it has been found that if the aerosol generating element in accordance with the present invention is heated to a temperature in the range of about 150 degrees Celsius to about 350 degrees Celsius, and heat is applied until no further decrease in mass is detected, then the residual mass of the aerosol generating element as typically less than 120 percent by weight of the continuous polymer matrix components, preferably less than 115 percent by weight of the continuous polymer matrix components, more preferably less than 115 percent by weight of the continuous polymer matrix components, even more preferably less than 105 percent by weight of the continuous polymer matrix components.

Most preferably, if the aerosol generating element in accordance with the present invention is heated to a temperature in the range of from about 150 degrees Celsius to about 350 degrees Celsius, and heat is applied until no further decrease in mass is detected, the residual mass of the aerosol generating element substantially corresponds to the total mass of the components continuous polymer matrix.

One embodiment of the invention will be further described below, by way of example only.

Example

An aerosol-generating solution was prepared from a mixture of the following components:

Component % by weight Glycerol 43.6 Sodium alginate 2.1 Nicotine 1.2 Levulinic acid 1.4 Water 51.7

At the initial stage, sodium alginate was added to water to obtain a matrix polymer solution. Nicotine was then added, followed by glycerin and finally levulinic acid.

The resulting aerosol generating solution was extruded through a 5 mm nozzle to produce a collection of droplets, which were then dropped from a height of 30 centimeters into a cross-linking solution having the following composition at room temperature:

Component % by weight Glycerol 42.9 Water 52.1 Calcium chloride 5.0

The droplets were left in the cross-linking solution for 25 minutes before being removed and dried at 25 degrees Celsius for 12 hours on a shelf dryer. The resulting dried aerosol generating elements were in the form of solid spherical granules with a diameter of approximately 4.6 mm. Each granule had a mass of approximately 65 mg, a water activity of 0.4 and the following composition:

Component % by weight Glycerol 76.8 Alginate 3.8 Nicotine 2.4 Levulinic acid 2.1 Water 14.4 Calcium chloride 0.5

Claims (14)

1. A method of manufacturing an aerosol-generating element for an aerosol-generating article or system, comprising the steps of: obtaining a solution of a matrix polymer containing a matrix-forming polymer in water; adding a plurality of components of an aerosol-generating composition to a matrix polymer solution to form an aerosol-generating solution, wherein the components of the aerosol-generating composition comprise a polyhydric alcohol and at least one alkaloid or cannabinoid, and the aerosol-generating solution contains at least 0.5 percent by weight of at least one alkaloid or cannabinoid; obtaining a discrete portion of the aerosol-generating solution; adding a discrete portion of the aerosol generating solution to the solution of multivalent cross-linking cations to cross-link the matrix-forming polymer; and removing the aerosol generating element from the solution to cross-link and dry the aerosol generating element. 2. The method of claim 1, wherein said components of the aerosol-generating composition further comprise an acid. 3. The method of claim 1 or 2, wherein said step of producing a discrete portion of the aerosol-generating solution includes producing a droplet of the aerosol-generating solution, and wherein the droplet flows into the cross-linking solution from a height of at least 10 cm. 4. A method according to any one of the preceding claims, wherein the viscosity of said aerosol generating solution is at least 5000 mPa⋅s. 5. A method as claimed in any one of the preceding claims, wherein said components of the aerosol generating composition are added sequentially to the matrix polymer solution. 6. The method of any one of the preceding claims, wherein said aerosol generating solution contains at least 20 percent by weight of a polyhydric alcohol. 7. A method as claimed in any one of the preceding claims, wherein said polyhydric alcohol is glycerol, propylene glycol, or a combination of glycerol and propylene glycol. 8. The method of any one of the preceding claims, wherein said aerosol generating solution contains at least 0.5 percent by weight of nicotine. 9. The method of any one of the preceding claims, wherein said matrix-forming polymer comprises alginate, and wherein the matrix polymer solution contains at least 45 percent by weight water. 10. The method of any one of the preceding claims, wherein said cross-linking solution contains at least 20 percent by weight of a polyhydric alcohol, wherein the polyhydric alcohol in the cross-linking solution is the same as the polyhydric alcohol in the aerosol generating solution. 11. The method of claim 10, wherein the concentration of said polyhydric alcohol in the cross-linking solution differs by no more than 20 percent from the concentration of the polyhydric alcohol in the aerosol generating solution. 12. The method of any one of the preceding claims, wherein during the drying step, the water content of said aerosol generating element is reduced to a level of less than 20 percent by weight. 13. The method according to any of the preceding claims, wherein after drying the polyhydric alcohol content of said aerosol generating element is at least 60 percent by weight. 14. An aerosol generating element, manufactured by the method of any of the preceding claims, containing at least 60 percent by weight of a polyhydric alcohol, at least 0.5 percent by weight of nicotine, and at least 0.5 percent by weight of an acid.