An Aerosol-Generating Substrate for Vaping Comprising Semi-Solid Substrate

Abstract

An aerosol-generating substrate for vaping includes a semi-solid substrate, wherein up to about 1.0% of the total weight percentage of the aerosol-generating substrate is comprised of one or more carboxylic acids dissolved in an alcohol solution. A method of manufacturing the aerosol-generating substrate and a use thereof in an aerosol-generating substrate for vaping are also provided.

Claims

1. An aerosol-generating substrate for vaping, comprising a semi-solid substrates, wherein up to about 1.0 wt. % of a total weight percentage of the aerosol-generating substrate is comprised of a carboxylic acid-containing alcohol solution, wherein one or more carboxylic acids are dissolved in the carboxylic acid-containing alcohol solution, wherein the semi-solid substrate is provided in the form of a foam.

2. The aerosol-generating substrate according to claim 1, wherein the aerosol-generating substrate comprises between 0.2 wt. % and 1 wt. % of the carboxylic acid-containing alcohol solution in the total weight percentage of the aerosol-generating substrate.

3. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution has a concentration of between about 0.05 v/v % and about 0.2 v/v %.

4. The aerosol-generating substrate according to claim 1, wherein the one or more carboxylic acids has a hydrocarbon chain length between 9 and 30 carbons.

5. The aerosol-generating substrate according to claim 1, wherein the one or more carboxylic acids is at least one of Benzoic acid, Levulinic acid, D/L-Tartaric acid, Capric acid, Pyruvic acid, Citric acid, Fumaric acid, D/L-Lactic acid, D/L-Malic acid, Sorbic acid, Adipic acid, L-Aspartic acid, L-Glutamic acid, Succinic acid, Gluconic acid, Linoleic acid, Saccharic acid, 3,7 dimethyl-6-octenoic acid, 2-methyl pentanoic acid, trans-2-Hexenoic acid, Caprylic acid, Lauric acid, Stearic acid, Butyric acid, Linolenic acid, Malonic acid, Myristic acid, Oleic acid, Palmitic acid, Phenylacetic acid, Propionic acid, Valeric acid, Decanoic acid, Hexanoic acid or Octanoic acid.

6. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution comprises only saturated fatty acid.

7. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution comprises only stearic acid and decanoic acid.

8. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution comprises only stearic acid or decanoic acid.

9. The aerosol-generating substrate according to claim 1, wherein the aerosol-generating substrate further comprises at least one of propylene glycol, 1, 3 propanediol, glycerol, water, gum, flavourant, additives, nicotine, or binder.

10. (canceled)

11. An aerosol-generating article comprises the aerosol-generating substrate according to claim 1.

12. A method of preparing an aerosol-generating substrate for vaping, comprising a semi-solid substrate in the form of a foam, comprising the steps of: a. providing an aerosol-generating substrate comprising at least one of propylene glycol 1, 3-Propanediol, glycerol or water; b. providing one or more carboxylic acids to an alcohol solution, followed by incorporating the one or more carboxylic acids-containing alcohol solution to the aerosol-generating substrate to form a mixture, such that up to about 1 wt. % of a total weight percentage of the aerosol-generating substrate is comprised of the one or more carboxylic acids-containing alcohol solution; and c. constantly mixing the mixture for a certain amount of time, and heating the mixture above room temperature, creating the semi-solid substrate in the form of a foam.

13. The method according to claim 12, wherein the one or more carboxylic acids-containing alcohol solution has a concentration of between about 0.05 v/v % and about 0.2 v/v %.

14. The method according to claim 12, wherein the mixture is heated at approximately 45° C. and/or aerated or mixed for approximately 5 minutes.

15. An aerosol-generating substrate obtainable by the method according to claim 12.

16. The method according to claim 12, further comprising, after step b, adding at least one of gum, nicotine, flavourant or binder into the mixture.

17. The aerosol-generating substrate according to claim 1, wherein the aerosol-generating substrate comprises about 0.2 wt. % of the carboxylic acid-containing alcohol solution in the total weight percentage of the aerosol-generating substrate.

18. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution has a concentration of between about between 0.08 v/v % and 0.15 v/v %.

19. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution has a concentration of 0.1 v/v %.

20. The aerosol-generating substrate according to claim 1, wherein the one or more carboxylic acids has a hydrocarbon chain length between 10 and 20 carbons.

21. The aerosol-generating substrate according to claim 1, wherein the carboxylic acid-containing alcohol solution comprises only stearic acid and decanoic acid in a ratio of 10/90 of stearic acid/decanoic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0052] Present invention relates to an improved aerosol-generating substrate and a method of producing the aerosol-generating substrate thereof. It has been found out that when the aerosol-generating (tobacco-containing) substrate of the present invention comprises up to 1.0 wt. % carboxylic acid (which is dissolved in a alcohol solution) of the total weight percentage of the aerosol-generating substrate, the carboxylic acid-containing aerosol-generating substrate surprisingly reduces throat irritation or coughing fit.

[0053] Vaper's cough is a condition not uncommon among vapers especially those who are new in e-vaping. Inhaling the vapour sometimes triggers a nasty coughing fit i.e. irritation causing coughing urge upon inhalation of an aerosol generated by heating of the substrate. There could be multiple factors for triggering such a coughing fit. For instance, some vapers are affected by the unadulterated nicotine in e-cigarettes, or the coughing may be triggered by inhaling too deeply, or too quickly, or the vaporizer's advanced settings are not fine-tuned accordingly.

[0054] While a certain throat irritation is welcome for a tobacco-based aerosol (as it is closer to the so-called “throat kick” sought after by cigarette smokers but not observed with e-cigarette aerosols), it is however necessary to control the irritation sensation caused by the aerosol to avoid actual coughing urge during consumption of a e-vaping material such as a tobacco mousse substrate.

[0055] In the present case, the inventors have investigated the possible alternative formulas of an aerosol-generating substrate which are particularly aimed at reducing coughing fit. The inventors found out that when up to about 1.0% of the total weight percentage of the aerosol-generating substrates are comprised of the one or more carboxylic acid in an alcoholic solution, the surprising effect of coughing fit reduction (or reduction of throat irritation) has been observed.

[0056] It is furthermore disclosed herein that the reduction of the coughing fit was particularly obvious when the aerosol-generating substrate comprises semi-solid substrate e.g. that the aerosol-generating substrate is provided in form of semi-solid substrate such as foam or mousse form or gel form. It is believed that the aerosol-generating substrate comprising carboxylic acid (especially for instance comprising stearic acid and/or decanoic acid), when in semi-solid state i.e. foam or gel, the higher surface to volume ratio allows the carboxylic acid to be vaporised or released more efficiently compared to when the aerosol-generating substrate is provided in a liquid or solid form.

[0057] In the present invention, the foam-stabilizing agent may be additionally introduced into the aerosol-generating substrate. The foam-stabilizing agent is not particularly limited as long as it can stabilize the foam to some extent after formation. According to certain embodiments, the foam stabilizing agent of the present foam is selected from the group consisting of cellulose gum, hydroxyalkylated carbohydrates, and mixtures thereof. Both of the cellulose gum and the hydroxyalkylated carbohydrates are not particularly restricted. According to certain, preferred, embodiments, the foam-stabilizing agent is a cellulose gum, particularly a carboxymethylcellulose, or a derivative thereof. An exemplary, preferred, cellulose gum which may be used in the present invention is CEKOL® 2000 and/or Ceroga 4550C (C.E. Roeper GmbH), a purified sodium carboxymethylcellulose each. Another class of suitable foam stabilizing agents are hydroxyalkylated carbohydrates, and more preferably cellulose ethers and derivatives thereof. A cellulose ether or derivative thereof that can be used can have at least one substituent selected from the group consisting of methyl, ethyl, hydroxyethyl and hydroxypropyl groups. It can further be substituted with a linear or branched substituted or unsubstituted alkyl radicals having 1-20 carbon atoms or an aralkyl radical having 7 to 20 carbon atoms. Such radical is preferably attached by an ether linkage. Suitable substituents can e.g. a hydroxy group, a carboxy group with 1 to 4 carbon atoms, etc. According to certain embodiments the cellulose ether is selected from hydroxyethylcellulose, methylcellulose, methylhydroxyethylcellulose, ethylhydroxyethylcellulose, and mixtures thereof. Furthermore, mixtures of different cellulose gums, different hydroxyalkylated carbohydrates, and mixtures of one or more cellulose gum with one or more hydroxyalkylated carbohydrate, as well as derivatives of one or either thereof, can be used. Also included as derivatives are salts of these cellulose ethers, preferably alkali metal salts thereof, e.g. sodium and/or potassium salts thereof.

[0058] Similarly, foam-forming agent may be additionally added to the mixture of aerosol-generating substrate. Also, the foam-forming agent is not particularly restricted. According to certain embodiments, the foam-forming agent of the present foam is selected from the group consisting of agar, gellan gum, lecithin, polyglycerol esters of fatty acids, glycerol esters of fatty acids, sorbitan esters of fatty acids, and/or mixtures thereof, without being limited thereto. A preferred foam-forming agent is gellan gum. Glycerol esters can be prepared by standard esterification methods. If glycerol esters of fatty acids are used, the foam-forming agent can suitably be a compound such as glycerol monostearate and/or glycerol monooleate. Polyglycerol esters can be prepared by polymerizing glycerin under alkaline conditions suitably followed by reacting them with specific fatty acids. Suitable polyglycerol esters can be hexaglycerol monooleate, octaglycerol monostearate and/or octaglycerol monooleate. Sorbitan esters of fatty acids used in certain embodiments of the present invention can be sorbitan monostearate, sorbitan monooleate and/or sorbitan mono palmitate. Furthermore, any possible combinations of compounds belonging to the above-mentioned classes can be used.

[0059] The present methods can be realized also through by having a step of mixing the aerosol-generating substrate that is aerated after adding of the foam-stabilizing agent and/or after cooling of the mixture. This does not exclude that other aeration steps are also being carried out, and according to certain embodiments, one, two or preferably all of the optional aeration steps are carried out in the present methods. Also, it is not excluded that aeration is carried out already concomitantly with a mixing and/or addition step.

[0060] The method of aeration is not particularly restricted and can involve e.g. an injection of air, a whipping in of air—e.g. a mixing with a sufficiently large paddle/shuffle and/or a sufficient paddle movement and/or at sufficient lower speed so that air can be introduced into the mixture, bubbling air through the mixture, etc. For example, aeration can be carried out using a sufficient mixing machine similar to a mixer for preparing a mousse, e.g. a Krups Prep & Cook HP 5031 mousse whipping shuffle, and or by injection air with an aerator, e.g. like Mondomix aerator. Aeration can be carried out at a suitable temperature, e.g. at room temperature (around 20-24° C.), 30-80° C., e.g. to 35-75° C., preferably between and including 30-60° C. In the present methods it is not excluded that aeration is carried out concomitantly with a mixing and/or in a step of adding an ingredient, e.g. when using whipping.

[0061] To this end, it is emphasized that the aerosol-generating substrate as claimed presently, even without adding additionally foam-forming agent and/or foam-stabilizing agent, with the above-explained method, the mixture of aerosol-generating substrate can be transformed into semi-solid condition i.e. foam, mousse, gel or the like. In other words, the aerosol-generating substrate of the present invention is a semi-solid substrate.

[0062] According to some embodiments of the present invention, ingredients for forming the aerosol-generating foam such as the aerosol-forming agent, the form-foaming agent, the foam-stabilizing agent, the tobacco-containing agent, the inhalable agent, the at least one non-tobacco flavoring agent and the solvent are not particularly restricted. Also, a gas used for aeration is not particularly restricted, and can be e.g. air. Also, further components can be admixed. According to certain embodiments, essentially no further components or no further components are admixed, though.

[0063] The aerosol-forming agent can further comprise water. According to certain embodiments, no water is contained, though, since water in aerosol form can burn the mouth of a user. Water can be contained in an amount of 0-15 wt.-% of the total weight percentage of the foam or the aerosol-generating substrate, e.g. 5-10 wt.-%.

EXAMPLES

Example 1

[0064] The present invention will now be described in detail with reference to examples thereof. However, these examples serve merely as illustrative purpose and do not limit the scope of the invention.

TABLE-US-00001 TABLE 1 Tobacco mousse (foam) containing different percentages of carboxylic acid-containing alcohol solution. Tobacco Mousse Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Propylene glycol  24 wt. %  24 wt. %  24 wt. %  24 wt. %  24 wt. % Glycerin (G)  36 wt.-%  36 wt.-%  36 wt.-%  36 wt.-%  36 wt.-% Stearic acid- and  0 wt.- % 0.2 wt. % 0.5 wt. % 0.8 wt. % 1.0 wt. % decanoic acid- containing alcohol solution Purified Water 3.5 wt.-% 3.5 wt.-% 3.5 wt.-% 3.5 wt.-% 3.5 wt.-% Tobacco Powder 21.5 wt. %  21.3 wt. %  21.0 wt. %  20.7 wt. %  20.5 wt. %  Gum 4.0 wt.-% 4.0 wt.-% 4.0 wt.-% 4.0 wt.-% 4.0 wt.-% Binder  11 wt. % 11.0 wt. %  11.0 wt. %  11.0 wt. %  11.0 wt. %  Total weight 100 wt. %.sup.  100 wt. %.sup.  100 wt. %.sup.  100 wt. %.sup.  100 wt. %.sup. 

[0065] Table 1 shows tobacco mousse (foam) comprising different weight percentages of carboxylic acids (i.e. stearic acid and decanoic acid)-containing alcohol solution were investigated. For producing exemplary foams, the ingredients given in the respective column of Table 1 were mixed and combined as follows.

[0066] An equal amount of stearic acid and decanoic acid has been used in all the samples, where these carboxylic acids are dissolved in an alcohol solution. It is believed that due to their chemical similarity, both stearic acid and decanoic acid can be used interchangeably or replaceable. The carboxylic acid-containing alcohol solution has a concentration of 0.1%.

[0067] Firstly, the propylene glycol, the glycerin, carboxylic acid alcohol solution (comprising an equal amount of stearic acid and decanoic acid) and optionally the purified water were whipped and aerated for 5-10 min, preferably at 6 min, at 45° C. using a Krups Prep & Cook HP5031 mousse whipping shuffle. When whipping up the mousse, the speed has to be adjusted so that the volume visibly increases, and small bubbles appear and partly stay in the foam. If whipping is too fast then mixing will take over and the foamy structure is going to collapse, thus back to fluid. As one option, whipping is started slowly and the whipping speed is slowly increased as the foam begins to develop a lighter, more mousse-like texture; the speed is backed-off by about 10% if it is noticed that the mousse seems to be reducing its mousse-like texture and becoming seemingly less aerated. In order to preserve the foamy structure for creating the stable portion, a sudden cooling with ice or cool water is recommendable. Using the above mentioned Krups device, the best results can be obtained with a speed in between 60 and 200 rpm. Adaptation is within the skilled person's knowledge in accordance with the above description.

[0068] In a next step (within 1 minute of the previous step), the gum was added, and the mixture was whipped and aerated for 5-10 minutes, preferably at 6 min, at 45° C. using a Krups Prep & Cook HP5031 mousse whipping shuffle. Afterwards the tobacco powder was added and whipping, and aeration were carried out for 5-10 min, preferably at 6 min, at 45° C. with the same method. Next, the binder was added, and the mixture was again whipped and aerated for 5-10 min, preferably at 6 min, at 45° C. with the same method. Finally, the mixture was placed in an oven at 50° C. for 12 hours before is ready to be packed and be used.

[0069] As no international standard of “sensory evaluation” for a coughing fit is available, the scoring of the “sensory evaluation” for the coughing fit is carried out as described below. Results obtained from the Example 1 were shown in the Table 2.

TABLE-US-00002 TABLE 2 Mean coughing fit scores rated by test subjects. Tobacco Mousse (TM) substrate Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Mean coughing fit score 71.25 36.25 33 39 37

[0070] In order to establish a mean coughing fit score, the Sample 1 (containing no carboxylic acid in the consumables) were first given to the test subjects to be rated. Each test subject inhaled 10 puffs within 3 minutes and the degrees of the throat irritation were rated (Score of 100 being very irritated; Score of 60 being rather irritated; Score of 30 being slightly irritated; Score of 0 being not irritated). After Sample 1 being rated, Samples 2, 3, 4 and 5 were given in a random order to the test subjects. The procedure was repeated similar as in the control sample (Sample 1). The coughing fit scores were rated by the test subjects based on their sensation to throat irritation. A pause of 60 seconds (or 120 seconds) is given before a new sample is given to the test subject.

[0071] As can be seen in the Table 2, the Samples 2, 3, 4 and 5 which comprised of 0.2 wt.-%, 0.5 wt.-%, 0.8 wt.-% and 1.0 wt.-% of carboxylic acid-containing alcohol solution, respectively, in the total weight percentage mixture of aerosol-generating substrate showed lower mean coughing fit scores compared to the control sample (Sample 1). As an example, the total weight of Sample 1 (0 wt. % Stearic acid and decanoic acid) is 500 g.

[0072] Sample 1 (control sample) which did not comprise any carboxylic acid (fatty acid) registered highest mean coughing fit score (71.25). It was observed that aerosol-generating substrates comprising 0.2 wt. % and 1.0 wt. % of carboxylic acid-containing alcohol solution based on the total weight percentage of the aerosol-generating substrates have significantly low scores i.e. less than 40 compared to the control Sample 1, namely 36.25, 33, 39 and 37 for Samples 2, 3, 4 and 5, respectively. These values represent only slightly throat irritation or coughing fit in the Samples 2 to 5 were observed as reported by various test subjects.

[0073] Furthermore, in addition to the reduced coughing fit as rated by the test subjects, it was also reported that in samples which comprised of up to 1 wt. % of carboxylic acid-containing alcohol based on the total weight percentage of the aerosol-generating substrate, the taste became smoother and without any negative off-taste, as observed in the Sample 1.

[0074] Although the lowest amount of the carboxylic acid-containing alcohol contains in the aerosol-generating substrate performed in the experiment was 0.2 wt. % based on the total weight percentage of the aerosol-generating substrate, it is believe that lower amount such as 0.1 wt. % or 0.05 wt. % based on the total weight percentage of the aerosol-generating substrate would be equally effective in suppressing throat irritation or is has a reduced coughing fit.

[0075] To this end, it is reiterated that this surprising effect of the present invention are observed only in any semi-solid substrate (foam, mousse, gel, mucus) and not applicable in solid or liquid medium.

[0076] The present foams according to the present invention are not smokable, i.e. are applied in a way that they are not heated to such temperature where they are combusted, but only at least parts thereof are evaporated, particularly at least essentially the aerosol-forming agent and further preferably at least a part of the tobacco-containing agent and/or the inhalable agent. In the present foams, at least some parts of the tobacco-containing agent and/or the inhalable agent preferably is adhered to the foam structure and/or absorbed by the foam structure formed essentially by the foam-forming agent and the foam-stabilizing agent, so that it can be easily released together with the aerosol-forming agent upon heating. Also, it is possible that some parts of the tobacco-containing agent and/or the inhalable agent are bound to the foam structure and the tobacco-containing agent and/or the inhalable agent are “extracted” during heating thereof, so that a flavour from the tobacco-containing agent and/or the inhalable agent is released thereof together with the aerosol-forming agent. According to certain embodiments, the tobacco ingredient containing agent and/or the inhalable agent is configured in such a way that it is released upon heating together with the aerosol-forming agent by only being essentially adsorbed to and/or absorbed in the foam structure. In this regard it was shown by the inventors that a mass loss in the foam can be observed that shows that essentially at least the mass of the foam-forming agent and the foam-stabilizing agent remains. It is assumed that the structure of the foam is mainly formed by the foam-forming agent, which forms a “capsulation” for adhering and/or absorbing the aerosol forming agent and the tobacco ingredient containing agent and/or an inhalable agent, whereas the foam-stabilizing agent stabilizes the foam to keep the foam form.