US20240130416A1

US20240130416A1 - Method for adjusting the nicotine content in an e-cigarette aerosol

Info

Publication number: US20240130416A1
Application number: US18/257,735
Authority: US
Inventors: Alp Ohri
Original assignee: Koerber Technologies GmbH
Current assignee: Koerber Technologies GmbH
Priority date: 2020-12-16
Filing date: 2021-12-01
Publication date: 2024-04-25

Abstract

A method for adjusting nicotine content of aerosol in an inhaler comprises: a feeding step in which at least one liquid having a first nicotine content is fed from a vaporizer tank to an electric vaporizer; a vaporizing step in which the at least one liquid is vaporized producing an aerosol; and a dispensing step in which a final aerosol consisting of a combination of all aerosols formed in the inhaler from the at least one liquid is dispensed from the inhaler to a user, wherein: at least one of the at least one liquid comprises a precursor substance capable of being converted into nicotine by a chemical reaction; and the method further comprises a nicotine generation step in which said precursor substance is converted into nicotine by the chemical reaction so that the final aerosol comprises a second nicotine content higher than the first nicotine content.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage of PCT/EP2021/083732 filed on Dec. 1, 2021, which claims priority to German Patent Application 102020133733.7 filed on Dec. 16, 2020, the entire content of both are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a method for adjusting the nicotine content of an aerosol in an inhaler, comprising the following steps:

- a feeding step in which at least one liquid having a first nicotine content is fed from a vaporizer tank to an electric vaporizer,
- a vaporizing step in which the at least one liquid is vaporized to produce an aerosol,
- a dispensing step in which a final aerosol consisting of the combination of all aerosols formed in the inhaler from the at least one liquid is dispensed from the inhaler to a user.

BACKGROUND OF THE INVENTION

Inhalers, particularly in the form of electronic cigarettes (hereinafter referred to as e-cigarettes) are used in the medical field and especially in the stimulants industry. E-cigarettes are enjoying great popularity and are increasingly replacing the use of conventional tobacco products. Unlike conventional tobacco products, in which the consumer inhales the smoke of burning plant parts, especially tobacco, no combustion of plant parts takes place in the e-cigarette. Instead, a fluid, usually referred to as liquid, is vaporized in a vaporizer unit and mixed with air in a flow channel, creating an aerosol, mist, or aerosol-vapor mixture that is inhaled by the consumer.
The liquid is stocked on or in the vaporizer cartridge. Various mixtures with different components of the same or different vapor densities are used as the liquid. A typical mixture for use in an e-cigarette has, for example, components of glycerin and propylene glycol, enriched by nicotine, optionally additionally with almost any flavoring.
As with conventional cigarettes the nicotine content for the cigarette has a maximum value, there are maximum values of nicotine in the liquid for the content of nicotine of an e-cigarette, which must not be exceeded. In the EU, for example, the nicotine content of e-cigarette liquids is limited to a concentration of 20 mg/ml. According to 2014/40/EU, this limit only applies to liquids. The nicotine concentration of the aerosols produced during vaporization is not limited.
The maximum permissible nicotine concentration in e-cigarette liquids in the EU is comparatively low. In the USA, on the other hand, e-cigarette cartridges are sold that are filled with liquids containing 5% nicotine. The popularity and the tobacco cigarette-like experience that e-cigarette smokers find pleasant are due not only to the nicotine salts in the liquids sold in the U.S., but also to the high concentration, because this can achieve a rapid increase in blood nicotine concentration comparable to that of tobacco cigarettes. It is desirable to achieve a similar blood nicotine concentration also with e-cigarette liquids complying with the regulations in the EU.

SUMMARY OF THE INVENTION

The task of the present invention is therefore to provide a method that enables an increased blood nicotine concentration to be achieved compared with that achievable with conventional liquids, while at the same time complying with the regulations of 2014/40/EU.
This task is solved with a method of the kind mentioned at the beginning in that at least one of the at least one liquid has a precursor substance which can be converted into nicotine by chemical reaction, and the method further comprises a nicotine generation step in which the precursor substance is converted into nicotine by chemical reaction so that the final aerosol has a second nicotine content which is higher than the first nicotine content.
In the context of the present invention, it has been found that it is possible to increase the nicotine content in the generated aerosol by adding to the liquid at least one substance that is transformed into nicotine only in the course of the formation of the aerosol. In this way, the nicotine content of the liquid can be kept within the legally prescribed values, while at the same time the aerosol inhaled by the consumer has a higher nicotine content desired by the consumer. The precursor substance is converted during the process and further on in the process reaches the consumer in the aerosol as nicotine.
The term aerosol as used in the present invention refers to the vapor phase formed by vaporization of the liquid and is also intended to include mist, vapor or mixtures of aerosol, mist and/or vapor, i.e., the gaseous phase may contain solid and/or liquid particles.
As chemical reaction by which the precursor substance is converted into nicotine, any chemical reactions are conceivable, substitutions, additions, eliminations, rearrangements, radical reactions or acid-base reactions. Particularly preferred, the chemical reaction is an oxidation or especially a reduction.
A chemical reduction is the reverse reaction of an oxidation, in which a reducing agent donates electrons to an already oxidized substance (thus “reducing” it).
Preferably, the conversion of the precursor substance to nicotine occurs with the use of a catalyst. The use of a catalyst enables conversions that would not be possible without the catalyst, or would be uneconomical, since, for example, too much energy would have to be supplied to initiate and/or carry out the reaction. The catalyst lowers the required activation energy by means of an intermediate reaction with the precursor substance. Thus, the reaction becomes more economical or even possible in the first place, because without the lowering, competing other reactions would take place that would not allow the actually desired reaction to occur or would do so only with very low yield.
Furthermore, it is particularly preferred if the conversion of the precursor substance into nicotine is carried out using an enzyme. Enzymes are proteins that usually selectively catalyze a specific reaction. Enzymes can also allow the conversion reaction of the precursor substance to nicotine to proceed under mild conditions
Nicotine has the following structural formula:
Various compounds are conceivable as precursor substance. In an advantageous embodiment, nicotine glucuronide or nornicotine can be used as a precursor substance. The former can be converted into nicotine by means of β-glucurodnidase, in particular immobilized on a filter or a column, the latter by reaction with methyltransferase. Enzymes are therefore used here. The precursor substance cotinine or nicotine N′-oxide is particularly preferred. Both compounds can be converted to nicotine in a reduction reaction. Cotinine can be found as an alkaloid in tobacco plants. The structural formulas of cotinine and nicotine N′-oxide are shown below:
Here, the reduction of cotinine or nicotine N′-oxide is preferably carried out by catalytic hydrogenation, using lithium alanate (LiAlH₄) in polar protic solvents or using other zinc hydride complexes. The reduction can thus be accomplished under mild conditions.
The precursor substance is preferably present in an amount such that a nicotine content of at least 30 mg/ml, preferably in particular at least 40 mg/ml and more preferably at least 50 mg/ml is obtained in the aerosol.
With the present invention, it is also possible to use liquids that do not contain any nicotine at all, but only precursor substances, so that the entire nicotine is thus present only in the aerosol.
The reactant may be present as a liquid in the liquid. Alternatively, the reactant can be a solid. It may either be inherently present as a solid or may have been converted to a solid by means of freeze-drying.
In another particularly preferred embodiment, the reactant is provided in a contact element, and in the nicotine production step the precursor substance is brought into contact with the reactant in the contact element. Filters are particularly suitable as such contact elements, as are grid structures. These are inserted into the air duct of an e-cigarette and, due to their large surface area, ensure intensive contact between the aerosol and, in particular, the precursor substance contained therein and the reactant contained in the filter. For solid reactants or reactants solidified by means of lyophilization (freeze-drying), a preferred mode is to apply nanoparticles or microparticles in order to achieve the largest possible surface area.
For liquid reactants, in a preferred embodiment a spraying system is used to load the aerosol with the respective liquid reactant. An alternative preferred embodiment employs a filter and a semi-permeable membrane to ensure egress of the reactant into the aerosol channel while preventing entry of the aerosol into the filter. Further alternatively, a pad impregnated with the liquid reactant can be placed in the air duct. In this case, the aerosol channel can be covered with the pad completely or partially, wherein any geometry can be used for the pad. Alternatively, a screen or grid can be used to absorb the liquid reactant. The sieve or grid is penetrated by the aerosol. In this way, the precursor substance to be reacted is reacted, with the increased surface area enabling particularly intensive contact between the reactant and the aerosol.
The above-described attachments in the form of pads, grids or filters are so-called “disposables”, i.e. consumables that would have to be disposed of and replaced after a certain number of cycles because, for example in the case of reducing agents, the redox potential is no longer existent after a certain number of cycles. Preferably, the number of puffs is recorded digitally and integrated into an app for controlling the e-cigarette. In this way, the consumer is reminded or made aware of how many puffs are still available and when it will be necessary to change the filter.
The nicotine generation step can take place before the vaporization step, after the vaporization step, or simultaneously with the vaporization step. Thus, the nicotine precursor can first be converted to nicotine and then transferred to the aerosol phase along with the rest of the liquid. Alternatively, the conversion takes place during the formation of the aerosol. Particularly preferably, the conversion of the precursor substance to nicotine takes place in the aerosol phase.
Furthermore, it is particularly preferred if the process is carried out in an inhaler having a vaporizer tank with at least two vaporizer tank chambers, wherein each vaporizer tank chamber can be assigned its own vaporizer. In this way, it is possible to transfer different liquids with different ingredients separately to the aerosol phase.
With such an embodiment with more than one vaporizer tank chamber, for example, working with several liquids is possible particularly well. Thus, a first liquid may contain nicotine and the precursor substance may be contained either in the first liquid or in a second liquid. Particularly preferably, the precursor substance is contained in a second liquid. In this way, the reaction to convert the precursor substance to nicotine can be carried out separately and there is no risk that the conversion reaction may cause undesirable reactions in the nicotine already present.
Furthermore, it is preferred that at least two liquids are used, wherein a first liquid contains nicotine and another liquid contains a reactant that causes the conversion of the precursor substance into nicotine. The first liquid may contain nicotine and the precursor substance, with the precursor substance reacting with the reaction agent only when the two liquids come together.
In this described variant, the liquid containing nicotine and the precursor substance and the liquid containing the reaction agent are transferred to the aerosol phase separately. The reaction of precursor substance with the reactant to form nicotine then takes place in the aerosol phase when the two aerosols, i.e., the aerosols of the first and the further liquid are combined. The combination allows for the reaction of the precursor substance with the reactant to nicotine to occur. The final aerosol is formed having the second nicotine content, which is higher than the first nicotine content.
Thus, particularly preferably, the second liquid contains both, the precursor substance and the reactant. Alternatively, as described above, the reactant may be provided in the form of a filter in the air duct for the second aerosol and may convert the precursor substance as it passes through the filter in the aerosol.
In the variant described above, the liquid containing nicotine and the liquid containing the precursor substance and possibly the reactant are transferred separately to the aerosol phase. The reaction of precursor substance with reactant to form nicotine thus takes place separately. It is only after conversion of the precursor substance to nicotine that the aerosol containing the newly generated nicotine is combined with the aerosol of the liquid that already contained nicotine at the beginning.
In a preferred embodiment, a three-tank system is used. This allows for the different substances to be stored separately from each other. In such a case, a first tank would contain a conventional liquid with the basic nicotine content. This nicotine content would preferably correspond to the maximum permissible nicotine content. Another tank contains a liquid containing the precursor substance. Finally, a third tank contains a liquid containing the reactant and, if desired and/or required, a carrier substance. In particular, the usual carrier substances such as water, propylene glycol (PG) and/or glycerol, in particular vegetable glycerol (“vegan glycerols”—VG), are suitable as carrier substances.
In a first step, the aerosol formation of the different liquids takes place. In a second step, the precursor substance is first reacted separately with the reaction agent to form nicotine. This avoids uncontrolled reaction of other components of the liquid with the reaction agent. For example, cotinine can first be reduced separately to nicotine, and it is avoided that other components of the liquid, such as flavors, are also reduced in an undesirable side reaction. Preferably, a multi-chamber system also has several separate vaporizers. In a third step, the aerosols are then mixed together to produce the final aerosol with increased nicotine content, which final aerosol is ultimately inhaled by the consumer.
In another preferred embodiment, conversion of the precursor substance into nicotine takes place before a and/or between two e-cigarette sessions. The necessary amount of precursor substance is stored in converted form and/or kept in the aerosol phase by means of supplying heat until the consumer starts the next session. In this way, reactions that require more time and energy to take place and deliver enough nicotine molecules can also be used. If the next session is not started for a longer period of time, the heating is stopped so that no unintended reactions take place due to the advanced time.

BRIEF DESCRIPTION OF THE DRAWINGS

Further useful and/or advantageous features and embodiments of the method for adjusting the nicotine content of an aerosol in an inhaler are apparent from the description. Particularly preferred embodiments will be explained in more detail with reference to the accompanying drawing. In the drawing:

FIG. 1 is a schematic representation illustrating the steps of a first embodiment of the method according to the invention;

FIG. 2 is a schematic representation illustrating the steps of a second embodiment of the method according to the invention;

FIGS. 3 a and 3 b are a schematic diagram illustrating the arrangement of a pad with reactant for carrying out the present invention; and

FIGS. 4 a and 4 b are a schematic illustration of the arrangement of a grid for absorbing reactant for carrying out the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a first vaporizer 1 in communication with a first tank 2 a and a second tank 2 b. The first tank 2 a contains a conventional liquid for an e-cigarette with a first nicotine content corresponding to the permissible nicotine content of 20 mg/ml, and with a certain content of cotinine. In the second tank 2 b there is a second liquid containing a reducing agent in addition to a carrier. The two liquids are vaporized forming an aerosol. A first aerosol 3 a with conventional e-liquid and cotinine and a second aerosol 3 b with carrier and reducing agent are formed. Both aerosols 3 a, 3 b are used in contact with each other, whereby the reducing agent reduces the cotinine to nicotine, so that the content of nicotine in the aerosol increases. The final aerosol 4 is formed, which has a second nicotine content that is higher than the first nicotine content.
FIG. 2 shows an embodiment with three different tanks 2 a, 2 b, 2 c, each of which is associated with a vaporizer 1 a, 1 b, 1 c. The first tank 2 a contains a conventional liquid with the basic nicotine content corresponding to the maximum permissible nicotine content of a liquid. A second tank 2 b contains a second liquid containing cotinine. Finally, the third tank 2 c contains a third liquid containing the reducing agent and PG as a carrier substance.
In a first step, the aerosol formation of the different liquids takes place. A first aerosol 3 a containing nicotine and aroma, a second aerosol 3 b containing cotinine, and a third aerosol 3 c containing the reducing agent and PG are formed.
In a second step, second aerosol 3 b and third aerosol 3 c are mixed, and the cotinine contained in the second aerosol 3 b is reduced to nicotine with the reducing agent contained in third aerosol 3 c. During this process, the second and third aerosols 3 b, 3 c are still separated from the first aerosol 3 a. This prevents other components of the liquid, such as flavors, which are contained in the first aerosol 3 a together with the nicotine, from reacting uncontrollably with the reaction agent and also being reduced in an undesirable side reaction.
In a third step, the aerosols are then mixed together to produce the final aerosol 4 with increased nicotine content, which is ultimately inhaled by the consumer.
FIG. 3 a shows an embodiment of an air duct 5 of an inhaler for carrying out the process according to the invention in side view, FIG. 3 b shows the same air duct 5 in top view. A filter 6 containing the nanoparticulate reducing agent is arranged in the air duct 5. The aerosol 3 b containing cotinine passes through the filter 6 and thereby comes into contact with the reducing agent, so that the cotinine contained in the aerosol 3 b is reduced to nicotine.
FIG. 4 a shows a further embodiment of an air duct 5 of an inhaler for carrying out the method according to the invention in side view, FIG. 4 b shows the same air duct 5 in top view. A sieve or grid 7 is arranged in the air duct, in which the liquid reducing agent is accommodated. This sieve 7 is penetrated by the aerosol 3 b, whereby the contained cotinine to be reduced can extensively be reduced due to the increased surface area and, still contained in the aerosol 3 b, reaches the consumer as nicotine.

Claims

1-11. (canceled)

12. A method for adjusting nicotine content of aerosol in an inhaler, the method comprising the following steps:

a feeding step in which at least one liquid having a first nicotine content is fed from a vaporizer tank to an electric vaporizer;

a vaporizing step in which the at least one liquid is vaporized producing an aerosol; and

a dispensing step in which a final aerosol consisting of a combination of all aerosols formed in the inhaler from the at least one liquid is dispensed from the inhaler to a user, wherein:

at least one of the at least one liquid comprises a precursor substance capable of being converted into nicotine by a chemical reaction; and

the method further comprises a nicotine generation step in which said precursor substance is converted into nicotine by the chemical reaction so that the final aerosol comprises a second nicotine content higher than the first nicotine content.

13. The method of claim 12, wherein the chemical reaction is an oxidation reaction.

14. The method of claim 12, wherein the chemical reaction is a reduction reaction.

15. The method of claim 12, wherein the nicotine generation step takes place before the vaporizing step, after the vaporizing step, or simultaneously with the vaporizing step.

16. The method of claim 12, wherein the precursor substance comprises cotinine or nicotine N′-oxide.

17. The method of claim 12, wherein the precursor substance comprises nicotine glucoronide or nornicotine.

18. The method of claim 12, wherein:

the method is carried out in the inhaler;

the inhaler comprises the vaporizer tank with at least two vaporizer tank chambers; and

each vaporizer tank chamber is configured to be assigned to a respective vaporizer.

19. The method of claim 12, wherein a first liquid of the at least one liquids contains nicotine and wherein the precursor substance is contained either in the first liquid or in a second liquid of the at least one liquids.

20. The method of claim 12, wherein at least two liquids are used, the at least two liquids comprising a first liquid containing nicotine and a further liquid containing a reactant, wherein the reactant causes the conversion of the precursor substance into nicotine.

21. The method of claim 20, wherein the reactant is provided in a contact element and wherein, in the nicotine production step, the precursor substance is brought into contact with the reactant in the contact element.

22. The method of claim 12, wherein the conversion of the precursor substance into nicotine is carried out using a catalyst.

23. The method of claim 12, wherein the conversion of the precursor substance into nicotine is carried out using an enzyme.