Claims:WE CLAIM:

1. A method for producing an aerosol generating substrate characterized by a reduced level of at least one aerosol constituents comprising the steps of:
(a) soaking a substrate in a non-aqueous solvent system to obtain a mixture;
(b) heating the mixture of step (a) at temperature in the range of 40°C to 65°C;
(c) cooling the mixture of step (b) at ambient temperature;
(d) decanting the solvent from the mixture of step (c) to obtain said aerosol generating substrate;
wherein said non-aqueous solvent system comprises at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent, wherein said aerosol generating substrate comprising at least one aerosol constituent in a range from about 0.1mg to about 10mg per gram of said aerosol generating substrate.

2. The method as claimed in claim 1, wherein said aerosol constituents are selected from a group consists of compounds such as nicotine, tobacco-specific nitrosamines (TSNA) including nitrosamine ketone (NNK) and N-nitrosonornicotine (NNN), Poly aromatic hydrocarbons such as benzo[a]pyrene B(a)P, nitrogen oxides (NOx), pyridines, CO or combinations thereof.

3. The method as claimed in claim 1, wherein said non-polar solvents are selected from the group consisting of alkyl and aryl hydrocarbons such as hexane, benzene, pentane, toluene and combinations thereof.

4. The method as claimed in claim 1, wherein said polar solvents are selected from the group consisting of alcohols such as methanol, ethanol, isopropyl alcohol, polyethylene glycol and combinations thereof.

5. The method as claimed in claim 1, wherein said pH modifying agents are derived from alkali, alkaline earth metals, carbonates, phosphates, preferably alkali hydroxides such as potassium hydroxide, sodium hydroxide, calcium hydroxide and combinations thereof.

6. The method as claimed in claim 1, wherein said non-aqueous solvent system comprises at least one non-polar solvent and at least one polar solvent in a v/v ratio of 9:1.

7. The method as claimed in claim 1, wherein the concentration of said pH modifying agent in said non-aqueous solvent system is in a range from about 0.1N to about 1N.

8. An aerosol generating substrate characterized by a reduced level of atleast one aerosol constituent, in a range from about 0.1mg to about 10mg per gram wherein said aerosol generating substrate is obtained by a method comprising the steps of:
(a) soaking a substrate in a non-aqueous solvent system to obtain a mixture;
(b) heating said mixture of step (a) at temperature in the range of 40°C to 65°C;
(c) cooling said mixture of step (b) at ambient temperature;
(d) decanting the solvent from the mixture of step (c) to obtain said aerosol generating substrate;
wherein said non-aqueous solvent system comprises of at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent.

9. The substrate as claimed in claim 8, wherein said aerosol constituents are selected from a group consists of compounds such as nicotine, tobacco-specific nitrosamines (TSNA) including nitrosamine ketone (NNK) and N-nitrosonornicotine (NNN), Poly aromatic hydrocarbons such as benzo[a]pyrene B(a)P, nitrogen oxides (NOx), pyridines, CO or combinations thereof.

10. The substrate as claimed in claim 8, wherein said non-aqueous solvent system comprises at least one non-polar solvent and at least one polar solvent in a v/v ratio of 9:1.

11. The substrate as claimed in claim 8, wherein concentration of said pH modifying agent in said non-aqueous solvent system is in a range from about 0.1N to about 1N.

12. The substrate as claimed in claim 8, wherein said non-polar solvents are selected from the group consisting of alkyl and aryl hydrocarbons such as hexane, benzene, pentane, toluene and combinations thereof.

13. The substrate as claimed in claim 8, wherein said polar solvents are selected from the group consisting of alcohols such as methanol, ethanol, isopropyl alcohol, polyethylene glycol and combinations thereof.

14. The substrate as claimed in claim 8, wherein said pH modifying agents are derived from alkali, alkaline earth metals, hydroxides, carbonates, phosphates, salts of weak acid - strong base and combinations thereof, preferably alkali hydroxides such as potassium hydroxide, sodium hydroxide, calcium hydroxide and combinations thereof.

15. A low odour aerosol generating article comprising an aerosol generating substrate of claim 1, wherein said aerosol generating substrate is characterized by a reduced level of at least one aerosol constituent.
, Description:Field of invention
The present invention generally relates to an aerosol generating substrate characterized by a reduced level of aerosol constituents resulting in low odour characteristics in said aerosol generating substrate.

MAIN APPLICATION DETAILS:
This application is a patent of addition to Indian Application No. 201731008522 filed on March 10, 2017, the contents of which are incorporated herein in their entirety by reference.

Background of the invention

Various parts of tobacco plant such as tobacco leaves, cut tobacco, midribs, stems and roots, which are consumed, contain different chemical constituents along with major component nicotine. These constituents are responsible for texture, flavour and other organoleptic properties of tobacco and its products. However, compounds like tobacco specific nitrosamine (TSNAs), polynucleararomatic hydrocarbons (PAHs) such as benzo (a) pyrene (BaP), carbonyls, phenol, and catechol are undesirable and toxic components of tobacco. Further the odour that emanates from the cigarette smoke may linger on fingers of a smoker while or post smoking. So there arises a need to develop an article with reduced lingering on hands of smoker post smoking.

US Patent no 1949012 describes a method of preparing tobacco free from nicotine. The method involves tobacco treatment with an organic solvent for substantial extraction of nicotine. Further, removing the nicotine from the extract by treating it with an acid aqueous washing liquid, steam distilling the washing liquid, shaking the distillate with the original extraction solvent, and combining any aromatic substances thus obtained and the other nicotine free extracts with the treated tobacco.

US Patent no 4068671 describes a tobacco treatment method for selective removal of nicotine without substantially removing soluble-constituents other than nicotine. The method involves the steps of: forming an aqueous dispersion of tobacco (pH around 8.5) and rapid air convection drying of said dispersion at 85 an elevated temperature and air flow rates, further rewetting the dried tobacco product with water, and repeating the dispersion and rapid drying steps to further reduce the nicotine content.

IN201731008522 provides a non-aqueous solvent system to reduce nicotine in tobacco however, the reduced levels range between 30 to 60% only, which appears not to solve the requisite industrial needs.

There is need for a simple and economical method to provide an aerosol generating substrate like tobacco characterized by a reduced level of aerosol constituents without significantly losing the tobacco integrity, or without necessitating costly and time-consuming extractive procedures, or is devoid of high throughput machines or technical complexities. There remains a particular need for a method to provide an aerosol generating substrate like tobacco characterized by a reduced level of nicotine.

Object of the Invention
It is an object of the present invention to overcome the drawbacks of the prior arts.

It is an object of the present invention to use energy efficient, simple method for effective removal of aerosol constituents with minimal impact on tobacco structural integrity.

It is yet another object of the present invention to provide an aerosol generating substrate characterized by a reduced level of atleast one aerosol constituents.

It is another object of the present invention to provide a method for producing an aerosol generating substrate with reduced level of atleast one aerosol constituents.

It is an object of the invention to provide an aerosol generating substrate characterized by a reduced level of atleast one aerosol constituents by using a novel solvent system.

It is a further object of the present invention to provide a low odour, aerosol generating product.

Summary of the invention
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention.

In yet another aspect of the present invention there is provided a method for producing an aerosol generating substrate characterized by a reduced level of aerosol constituents comprising the steps of: (a) soaking a substrate in a non-aqueous solvent system to obtain a mixture; (b) heating the mixture of step (a) at temperature in the range of 40°C to 65°C; (c) cooling the mixture of step (b) at ambient temperature; (d) decanting the solvent from the mixture of step (c) to obtain said aerosol generating substrate, wherein said non-aqueous solvent system comprises at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent, wherein said aerosol generating substrate comprising at least one aerosol constituent in a range from about 0.1mg to about 10mg per gram of said aerosol generating substrate.

In an aspect of the present invention there is provided an aerosol generating substrate characterized by a reduced level of at least one aerosol constituent comprising at least one aerosol constituent, preferably nicotine in a range from about 0.1mg to about 10mg per gram wherein said aerosol generating substrate is obtained by a method comprising the steps of: (a) soaking a substrate in a non-aqueous solvent system to obtain a mixture; (b) heating said mixture of step (a) at temperature in the range of 40°C to 65°C; c) cooling said mixture of step (b) at ambient temperature; (d) decanting the solvent from the mixture of step (c) to obtain said aerosol generating substrate, wherein said non-aqueous solvent system comprises of at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent.

In an another aspect of the present invention there is provided a low odour aerosol generating article comprising an aerosol generating substrate as described herein, wherein said aerosol generating substrate is characterized by a reduced level of at least one aerosol constituents.

In an embodiment, the aerosol constituents are selected from a group consists of compounds such as nicotine, tobacco-specific nitrosamines (TSNA) including nicotine-derived nitrosamine ketone (NNK) and N-nitrosonornicotine (NNN), poly aromatic hydrocarbons such as benzo[a]pyrene B(a)P, nitrogen oxides (NOx), pyridines, CO or combinations thereof. In a preferred embodiment, the aerosol constituent is nicotine.

Other aspects, advantages and salient features of the invention will become apparent to those skilled in the art from the detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

Brief description of accompanying Drawings

The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:
Figure 1 illustrates the flow diagram of the process of removal of aerosol constituents from aerosol generating substrate.

Detailed description of present invention

The present invention relates to a method of producing an aerosol generating substrate with reduced levels of aerosol constituents.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof. Also, Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

As used herein, “an aerosol generating substrate” or “a substrate” refers to conventional tobacco used in manufacturing of cigarettes.

As used herein, a “low odour aerosol generating article” or simply “an aerosol generating article” refers to cigarettes. It can also include heat not burn (HNB) aerosol generating smoking substrates which provide similar attributes as that of conventional cigarettes.

The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure.

It is an important embodiment of the present invention, to provide an aerosol generating substrate with reduced level of aerosol constituents.

The method of removing aerosol constituents from tobacco is illustrated in Figure 1.

In first embodiment of the present invention, there is provided an aerosol generating substrate characterized by a reduced level of aerosol constituents, comprising at least one aerosol constituent in a range from about 0.1mg to about 10mg per gram wherein said aerosol generating substrate is obtained by a method comprising the steps of:
(a) soaking a substrate in a non-aqueous solvent system to obtain a mixture;
(b) heating under reflux said mixture of step (a) at temperature in the range of 40°C to 65°C;
(c) cooling said mixture of step (b) at ambient temperature;
(d) decanting the solvent from the mixture of step (c) to obtain said aerosol generating substrate, wherein said non-aqueous solvent system comprises at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent.

In second embodiment of present invention, there is provided a low odour aerosol generating article comprising an aerosol generating substrate characterized by a reduced level of atleast one aerosol constituents resulting in low odour characteristics, wherein said aerosol generating substrate is obtained by a method comprising steps of:

(a) soaking a substrate in a non-aqueous solvent system to obtain a mixture;
(b) heating under reflux said mixture of step (a) at temperature in the range of 40°C to 65°C;
(c) cooling said mixture of step (b) at ambient temperature;
(d) decanting the solvent from the mixture of step (c) to obtain said aerosol generating substrate,
wherein said non-aqueous solvent system comprises of at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent.

The method provides an aerosol generating substrate characterized by a reduced level of aerosol constituents comprising at least one aerosol constituent in a range from about 0.1mg to about 10mg per gram of said aerosol generating substrate, preferably in the range of about 0.1mg to 2 mg per gram of said aerosol generating substrate.

In an embodiment of present invention, there is provided a non-aqueous solvent system wherein said non-aqueous solvent system comprises at least one non-polar solvent and at least one polar solvent in a combination with at least one pH modifying agent.

Saidnon-polar solvents are selected from alkyl and aryl hydrocarbons such as hexane, benzene, pentane, toluene and combinations thereof. In a preferred embodiment the non-polar solvent is hexane.

Said polar solvents are selected from alcohols such as methanol, ethanol, isopropyl alcohol, polyethylene glycol and combinations thereof. In a preferred embodiment the polar solvent chosen is isopropyl alcohol.

The pH modifying agents are derived from inorganic bases more preferably alkali or alkaline earth metals, hydroxides, carbonates, phosphates, salts of weak acid - strong base and combinations thereof. Preferably, the pH modifying agents are selected from alkali hydroxides such as potassium hydroxide, sodium hydroxide, calcium hydroxide and combinations thereof. In a preferred embodiment, the pH modifying agent chosen is potassium hydroxide.

In one embodiment, the non-polar solvent is hexane and the polar solvent is isopropanol and the pH modifying agent is potassium hydroxide. In a preferred embodiment of the invention, the solvent system comprises nine parts of hexane and one part of a 0.6 N solution of potassium hydroxide in isopropanol.

In an embodiment, said substrate is adapted in the manufacturing of an aerosol generating article such that the aerosol generating article is characterized by a reduced level of aerosol constituents contributing to low odour.

The present invention also relates to a low odour aerosol generating article comprising an aerosol generating substrate as described herein, wherein said aerosol generating substrate is characterized by a reduced level of at least one aerosol constituent.

The method for reducing aerosol constituents like nicotinein the aerosol generating substrate brings about reduction of nicotine to levels of = 0.5 mg (of nicotine in blend per gm of tobacco) or 97% reduction in blend nicotine.

In an embodiment, 9 parts of the non-polar solvent is used and 1 part of the polar solvent is used along with the 0.1N to about 1N of suitable pH modifying agents to achieve 0.1 mg to 10 mg/gm of atleast aerosol constituents of a aerosol generating substrate. The non-polar solvent alone or outside the range cannot bring about the required reduction of aerosol constituents and the polar solvent alone or outside the range also reduces the components other than nicotine and also negatively impacts structural integrity of the substrate.

The aerosol generating substrate characterized by a reduced level of aerosol constituents can be directly made in to combustible products using standard procedures known for those skilled in the art. When such combustible products were evaluated for deliveries, proportional reduction of aerosol constituents was observed in the smoke as well.

It is another embodiment of the present invention, there is provided a low odour aerosol generating article comprising an aerosol generating substrate characterized by a reduced level of aerosol constituents.

The low odour aerosol generating article comprising an aerosol generating substrate characterized by a reduced level of aerosol constituents results in low odour characteristics.

In an embodiment, 9 parts of the non-polar solvent is used and 1 part of the polar solvent is used. The non-polar solvent alone or outside the range cannot bring about the required reduction in aerosol constituents and the polar solvent alone or outside the range reduces other components than desired aerosol constituents and also results in altering the structural integrity of the substrate.

In an embodiment, the optimum concentration or preferred range of pH modifying agent to be used in the non-aqueous solvent system of present invention is in a range from about 0.1N to about 1N, a concentration below 0.1N does not result in desired aerosol constituents reduction while concentration above 1N increases alkalinity of the tobacco which affects the lamina/tobacco structure.

Pure hexane shows difficulty in solubilizing the pH modifying agent and does not bring about the required levels of reduction in desired aerosol constituents. On the other hand, pure isopropanol brings reduction of several other constituents in addition to the reduction of desired aerosol constituents.

The present invention provides a method for producing the aerosol generating substrate characterized by a reduced level of atleast one aerosol constituents does not degrade the tobacco and the washed tobacco can be dried and be readily made into a combustible product.

The method of the present invention for producing an aerosol generating substrate characterized by a reduced level of aerosol constituents brings about reduction of aerosol constituents to a level of 0.1 mg to 2 mg per gm of said substrate or 97% reduction in a blend whereby acceptable/processable structural integrity of the substrate is maintained with respect to control and the substrate is obtained in good yield (or minimal operational loss).

Henceforth, embodiments of the present disclosure are explained with one or more examples. However, such examples are provided for the illustration purpose for better understanding of the present disclosure and should not be construed as limitation on scope of the present disclosure.

Examples 1: Production of an aerosol generating substrate with the reduced levels of atleast one aerosol generating constituent such as nicotine.

Substrate with initial levels of nicotine from about 14 mg – 20 mg was soaked in a solution whose volume is 15 times by volume w.r.t. substrate (tobacco) weight. Solution was made up of 9 parts of hexane and one part of potassium hydroxide in isopropyl alcohol, wherein concentration of said potassium hydroxide is in a range from about 0.1- 1.0 N in isopropanol. This mixture termed as stock mixture, was heated at reflux for about 15-24hours. Cooling to ambient temperature for about 1 – 2 hours, decanting of solvent from said mixture and drying of substrate for about 4 -6 hours, said substrate then comprises of nicotine levels of about 2mg -7 mg of nicotine per gm of said substrate.
The substrate with 2mg – 7 mg of nicotine per gram of substrate was again soaked in said solution, the mixture was heated at reflux for about 15-24 hours followed by cooling to ambient temperature for about 1-2 hours decanting of solvent from said mixture and drying said substrate for about 4-6 hours, said substrate then comprises of nicotine level of about 0.7 mg - 1.9 mg of nicotine per gm of said substrate.
Substrate with 0.7mg –1.9 mg mg of nicotine per gm of substrate was further treated with the said solution, the mixture was heated at reflux for about 15-24 hours followed by cooling to ambient temperature for about 1-2 hours, decanting of solvent from said mixture and drying said substrate for about 4-6 hours, said substrate then comprising of nicotine level of about 0.7 mg - 1.9 mg of nicotine per gm of said substrate.
Smoke Analysis at different levels of reduced levels of atleast one aerosol generating constituent in the substrate blend

The nicotine content in the smoke generated from the substrate is low due to the reduction of nicotine in the substrate. The nicotine level before washing (control) is 14.5 mg/gm of substrate. After repeated washing of the substrate the nicotine level in the substrate was reduced. Table 1 shows the nicotine levels in smoke corresponding to nicotine levels in substrate.

Table 1: Smoke Analysis of different levels of reduced nicotine corresponding to the nicotine in the substrate blend
Nicotine levels in substrate blend after washing (mg/gm) Nicotine levels in smoke (mg)
6 (First / initial washing) 0.24
1.4 (Second / subsequent washing) 0.1
0.5 (Third washing which results in 97% reduction in nicotine) 0.1

The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention, in addition to those described herein, will become apparent to those skilled in the art from the foregoing description and accompanying figures. Such modifications are intended to fall within the scope of the appended claims. The invention is, therefore, to be limited only by the terms of the appended claims along with the full scope of equivalents to which the claims are entitled.