Aerosol-generating material for use in an aerosol delivery system

Abstract

The present disclosure relates to an aerosol-generating material for use in an aerosol delivery system, comprising one or more aerosolisable components bound in a matrix, and one or more aerosolisable components that are not bound in said matrix. The present disclosure also relates to articles for use in non-combustible aerosol provision devices, comprising the aerosol-generating material, methods of manufacturing such materials and articles, and systems for providing an aerosol.

Description

[0001] Aerosol-generating material for use in an aerosol delivery system

[0002] Field

[0003] The present disclosure relates to an aerosol-generating material for use in an aerosol provision system, comprising one or more aerosolisable components bound in a matrix, and one or more aerosolisable components that are not bound in said matrix. The present disclosure also relates to articles for use in non-combustible aerosol provision devices, comprising the aerosol-generating material, methods of manufacturing such materials and articles, and systems for providing an aerosol.

[0004] Background

[0005] Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Alternative smoking articles produce an inhalable aerosol or vapour by releasing compounds from a substrate material without burning. These articles may be referred to as non-combustible smoking articles or aerosol provision systems. Such articles commonly include a portion comprising aerosol generating composition.

[0006] Summary

[0007] In accordance with embodiments described herein, in a first aspect there is provided an aerosol-generating material for use in an aerosol provision system, comprising : one or more aerosolisable components having a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C bound in a matrix comprising one or more binders, wherein the one or more binders are selected to release the bound aerosolisable components upon heating to a target temperature; and one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C that are not bound in said matrix.

[0008] In some embodiments, the one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C are not bound in any matrix.

[0009] In some embodiments, the one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C are bound in a second matrix which releases the bound aerosolisable components upon heating to a temperature above about 50°C. In some embodiments, the second matrix is in the form of one or more selected from the group consisting of: beads, tablets, granules, powder or coating.

[0010] In some embodiments, the one or more binders are selected to release the bound aerosolisable components upon heating to a target temperature range from about 180 to about 300°C.

[0011] In some embodiments, the binder comprises sodium alginate or calcium alginate.

[0012] In some embodiments, the aerosol-generating material further comprises tobacco material or a tobacco extract.

[0013] In some embodiments, the aerosolisable components are flavour components selected to complement and / or enhance the tobacco flavour of the aerosol generated from the aerosol-generating material.

[0014] In some embodiments, the aerosolisable components are flavour components that do not provide the aerosol with a distinctive non-tobacco flavour.

[0015] In some embodiments, the aerosolisable components do not include menthol.

[0016] In some embodiments, the matrix comprising one or more binders selected to release the bound aerosolisable components upon heating to a target temperature range from about 180 to about 300°C is in the form of substantially spherical beads.

[0017] In some embodiments, the beads have a mean diameter of from about 2 to about 5 mm.

[0018] In some embodiments, the binder is cross-linked.

[0019] In some embodiments, the aerosol-generating material further comprises an aerosolformer material.

[0020] In some embodiments, the aerosol-generating material comprises from about 0.1 to about 60 wt% aerosol-former material.

[0021] In some embodiments, the aerosol-former material comprises glycerol and / or propylene glycol. In some embodiments, the matrix comprises substantially no aerosol former material.

[0022] In some embodiment, the aerosol-generating material comprises less than about 10 wt% or less than about 7 wt% water.

[0023] According to a second aspect of the present invention, there is provided an article for use in an aerosol provision system, a portion of the article comprising the aerosolgenerating material according to the first aspect.

[0024] According to a third aspect of the present invention, there is provided a noncombustible aerosol-provision system comprising the aerosol-generating material according to the first aspect or an article according to the second aspect.

[0025] In some embodiments, the system is configured to heat the aerosol-generating material to form a vapour and / or aerosol.

[0026] According to a fourth aspect of the present invention, there is provided a method for preparing an aerosol-generating material according to the first aspect, comprising : forming a slurry comprising one or more aerosolisable components having a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C and one or more binders; solidifying the slurry; and freeze drying the solidified slurry to form a matrix; combining the matrix with one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C.

[0027] In some embodiments, the slurry is solidified to form a solid or semi-solid by crosslinking droplets or a jet of the slurry.

[0028] In some embodiments, the droplets or jet are cross-linked by being dispensed into a bath comprising a cross-linking agent.

[0029] In some embodiments, the slurry is solidified by rapidly freezing droplets or a jet of the slurry.

[0030] In some embodiments, the droplets or jet are frozen by being dispensed into liquid nitrogen. In some embodiments, the solidified slurry is freeze-dried at a temperature of from about -35 to about -50°C at from about 30 to about 40 pbar.

[0031] In some embodiments, the solidified slurry is freeze-dried for a period of from about 12 or about 24 hours to about 100 hours.

[0032] In some embodiments, the method comprises a secondary drying step.

[0033] In some embodiments, the secondary drying step involves increasing the temperature of the freeze-dried solidified slurry to a secondary drying temperature to from about + 15°C to about +25°C.

[0034] In some embodiments, the freeze-dried solidified slurry is held at the secondary drying temperature for a period of from about 10 hours to about 25 hours.

[0035] In some embodiments, the solidified slurry is in the form of one or more beads and / or one or more strands.

[0036] In some embodiments, the solidified slurry is in the form of one or more strands and the one or more strands are cut to form particles or segments before or after freeze- drying.

[0037] According to a fifth aspect of the present invention, there is provided use of the aerosol-generating material according to the first aspect to provide sustained release of flavour into an aerosol.

[0038] Brief Description of the Drawings

[0039] Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:

[0040] Figure 1 is a side-on cross-sectional view of a first embodiment of a consumable comprising an aerosol-generating material according to the invention.

[0041] Figure 2 is a perspective illustration of a non-combustible aerosol provision device for generating a flavoured aerosol from the aerosol-generating material of the consumable shown in Figure 1.

[0042] Figures 3A to 3G are chromatograms acquired by TDU-MS (thermal desorption unitmass spectrometry) showing the temperature-dependent release of selected compounds from control compositions and samples of a matrix material comprising aerosolisable flavour components.

[0043] Figures 4A to 4E are chromatograms showing the temperature-dependent release of multiple compounds from each of the control compositions and samples of a matrix material comprising aerosolisable flavour components.

[0044] Figure 5 is a graph showing the puff-by-puff flavour release of ethyl butyrate from a sample containing a liquid flavour composition and from samples containing the solid flavour-generating material according to the invention in a consumable when heated by a two-zone heating device.

[0045] Figures 6A and 6B are graphs showing the puff-by-puff flavour release of a range of flavour compounds from samples of the solid flavour-generating material according to the invention in a consumable when heated by a two-zone heating device.

[0046] Detailed Description

[0047] The present invention seeks to provide an aerosol-generating material for use in an aerosol provision system. The aerosol-generating material may be provided in an article or consumable for use in the aerosol provision system.

[0048] The provision of a flavour in a matrix as an aerosol-generating material for use in an aerosol provision system is known. However, conventional aerosol-generating materials frequently suffer from the problem that it is difficult to control the release of the flavour at a predetermined temperature. The flavours tend to be volatile compounds and so their release is dependent upon the properties of the matrix in which they are provided.

[0049] A further difficulty is the provision of an aerosol-generating material that includes the flavour in a concentration that is high enough to provide an intense flavour when heated.

[0050] Where the flavour to be incorporated into the aerosol comprises a combination of flavour components with different volatilities, that is, different vapour pressures or boiling points, control of release of the flavour can be even more difficult. Whilst highly volatile flavour components need to be incorporated into a matrix to prevent migration and loss before use, it can actually be disadvantageous to incorporate the less volatile flavour components in the same matrix. This is because the release of such less volatile flavour components from a matrix can be relatively poor, with only a relatively small proportion of the entrapped less volatile components being released when the matrix disintegrates upon heating. Therefore, according to the present invention, one or more aerosolisable components having a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C bound in a matrix comprising one or more binders, wherein the one or more binders are selected to release the bound aerosolisable components upon heating to a target temperature; and one or more aerosolisable components having a vapour pressure of less than about 8 Pa and / or a boiling point of above about 180°C that are not bound in said matrix.

[0051] Herein, the aerosolisable components, which will include flavour components, are described as being "highly volatile" where they have a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C. Aerosolisable components are described as being "less volatile" where they have a vapour pressure of less than about 8 Pa and / or a boiling point of above about 180°C.

[0052] In the present invention, the matrix used to bind or entrap the highly volatile aerosolisable components serves multiple purposes. Firstly, the matrix traps the flavour and prevents its migration and release during storage. Secondly, the matrix stably binds and holds flavour in high concentrations. Thirdly, upon heating, the matrix breaks down chemically and / or physically, to allow the flavour to be released. The temperature of this breakdown of the matrix (also referred to herein as the "release temperature") will depend upon the materials used to form the matrix. Fourthly, the shape or form of the matrix will influence the rate at which the flavour is released once the release temperature is reached and / or exceeded.

[0053] Thus, providing the highly volatile aerosolisable components in a matrix prevents loss of the components before use and ensures that their release is provided in a controlled and predetermined manner upon heating the aerosol-generating material to a target temperature. Providing the less volatile aerosolisable components in the aerosolisable material but separate from this matrix means that these components can also be efficiently and effectively released in a temperature-dependent manner, without undue loss or wastage.

[0054] Matrix comprising one or more highly volatile aerosolisable components

[0055] There is provided an aerosol-generating material for use in an aerosol provision system, comprising one or more highly volatile aerosolisable components bound in a matrix comprising one or more binders, wherein the one or more binders are selected to release the flavour upon heating to a target temperature range. These aerosolisable components may be flavour components.

[0056] In some embodiments, at least about 90% of the total aerosolisable component(s) entrapped in the matrix is released from the matrix and / or aerosol-generating material whilst the matrix is at a temperature within the target temperature range.

[0057] The release of the highly volatile aerosolisable component(s) may be controlled, not just in terms of the temperature at which it occurs, but optionally also in terms of the rate at which the highly volatile components are released once the release temperature is reached.

[0058] Many aerosol provision systems, including non-combustible systems, heat aerosolgenerating material to a predetermined operating temperature which is generally between about 180°C and about 300°C.

[0059] Therefore, in some embodiments, the target temperature range within which the highly volatile components are released is from about 90 to about 300°C.

[0060] Upon heating the aerosol-generating material, the binder and / or the matrix thermally decomposes or degrades, thereby releasing the bound or entrapped highly volatile component(s). The temperature at which the decomposition or degradation occurs will depend on the nature of the binder used. The rate at which this decomposition or degradation occurs will depend upon the shape and density of the matrix and / or the aerosol-generating material. Thus, the binder and the shape and / or density of the matrix may be selected to control the release of the bound highly volatile component(s).

[0061] For example, a matrix in the form of a sheet or thin film will release bound or entrapped components faster than a bead once the matrix begins to decompose or degrade having been heated to the target temperature range. It is hypothesised that the bound or entrapped components have further to migrate from within the bead than from within the sheet or film. In such a scenario, the thin film might, for example, have a thickness of from about 100 to about 150 pm, whilst the beads would have a diameter in the millimetre range.

[0062] In some embodiments, the aerosol-generating material or matrix has a density in the range of from about 0.05 to about 1.5 g / cm3. In some embodiments, the aerosol-generating material or matrix has a mean density of at least about 0.05 g / cm3, at least about 0.1 g / cm3, at least about 0.2 g / cm3, at least about 0.3 g / cm3, at least about 0.4 g / cm3, at least about 0.5 g / cm3, at least about 0.6 g / cm3, at least about 0.7 g / cm3, and / or a mean density of no greater than about 1.5 g / cm3, no greater than about 1.4 g / cm3, no greater than about 1.3 g / cm3, no greater than about 1.2 g / cm3, no greater than about 1.1 g / cm3, no greater than about 1 g / cm3no greater than about 0.9 g / cm3, no greater than about 0.8 g / cm3, no greater than about 0.7 g / cm3, no greater than about 0.6 g / cm3, no greater than about 0.5 g / cm3, no greater than about 0.4 g / cm3, no greater than about 0.3 g / cm3, no greater than about 0.2 g / cm3, or no greater than about 0.1 g / cm3.

[0063] It is hypothesised that the bound or entrapped highly volatile component or components will take longer to migrate from within a higher density matrix than from a lower density matrix.

[0064] When the aerosol-generating material is used to generate an aerosol, the matrix must be broken down in order to release the bound or trapped highly volatile component(s). When no longer bound or entrapped within the matrix, the highly volatile component is able to migrate and volatilise. The density and the porosity of the matrix will affect the rate at which the highly volatile component is able to migrate and thus, its rate of release. Thus, for example, the highly volatile component is released more quickly from a porous, less dense matrix, because there is a great surface area to volume ratio and because the distance to the surface of the matrix will generally be reduced by the pores and channels in the matrix. Where the matrix comprises a cross-linked material, the porosity of the matrix may be controlled by the degree of cross-linking. High degrees of cross-linking may result in water being expelled by syneresis as the matrix is formed, reducing the porosity of the resultant matrix. The degree of crosslinking may also affect the rate of degradation or decomposition of the matrix when the matrix is heated to the target temperature range, with greater cross-linking resulting in slower degradation or decomposition of the matrix.

[0065] By the same principle, the shape of matrix will also affect the rate of the highly volatile component release, as the dimensions will determine how far the component has to migrate to reach the surface of the matrix. Thus, for example, the highly volatile component is released more quickly from a thin sheet of matrix with a thickness of 1 mm than from beads of matrix having a diameter of 3 mm. In view of this, it is clearly desirable to be able to produce an aerosol-generating material comprising a matrix with the desired density and / or porosity, and to also to control the size and geometry of the matrix.

[0066] In some embodiments, the matrix is provided in the form of shaped particles. The term "shaped" as used herein means that the particles have a controlled and predetermined shape. These particles are not, for example, formed by creating a larger dried mass which is then broken up into particles. Such a process would not provide particles of a controlled and predetermined shape. Instead, shaped particles are formed by drying a precursor composition, such as a slurry, which has been preformed into the desired shape. As discussed below, there are different ways to achieve this.

[0067] Matrix provided in the form of shaped particles has a number of beneficial properties. Firstly, the composition of each shaped particle may be accurately controlled.

[0068] Secondly, the size and the geometry or form of each particle may be accurately controlled. Thirdly, in some embodiments, the shaped particles can be free-flowing and easy to handle, store and process.

[0069] Significantly, the ability to manufacture shaped particles with a predictable composition, size and geometry means that the particles may be used to provide an accurate, controlled and predictable delivery of the highly volatile component upon use. Further, a population of particles comprising a mixture of different particles (i.e., a mixture of particles with different properties) may be used to provide desired delivery profiles over a period of time.

[0070] Binder in the matrix comprising the highly volatile component(s)

[0071] One of the key factors influencing the temperature-dependent release of the highly volatile component(s) from the aerosol-generating material is the one or more binder used to form the matrix and bind or entrap the one or more highly volatile components.

[0072] Each binder included in the matrix will have a temperature at which the binder breaks down. This breakdown of the binder allows the bound or entrapped component(s) to be released from the matrix. The one or more binders included in the matrix are selected to ensure that the matrix disintegrates and releases the bound or entrapped component(s) when heated to a target temperature range. In some embodiments, the binder is one or more compounds selected from: polysaccharide binders, such as alginates, pectins, starches or derivatives thereof, cellulose or derivatives thereof, pullulan, carrageenan, agar and agarose; gelatin; gums, such as xanthan gum, guar gum and acacia gum; silica or silicone compounds, such as PDMS and sodium silicate; clays, such as kaolin; and polyvinyl alcohol.

[0073] In some embodiments, the polysaccharide binder is selected from the group consisting of alginate and a cellulose derivative, and / or wherein the cellulose derivative is selected from hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), methyl cellulose, ethyl cellulose, cellulose acetate (CA), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP).

[0074] In some embodiments, the aerosol-generating material comprises one or more binder in a total amount of from about 10 to about 50 wt% binder calculated on a dry weight basis (DWB). In some embodiments, the total amount of binder in the aerosolgenerating material is from 20 to 40 wt% (DWB).

[0075] Different binders break down at different temperatures. In some embodiments, the breakdown of the binder refers to the melting of the binder. This melting may be thermoreversible (for example, in the case of carrageenan), or thermally irreversible. Where a combination of two or more binders are used, the flavour will be released when the aerosol-generating material and / or matrix is heated to the lowest temperatures at which one of the binders breaks down. Thus, the temperature at which the bound or entrapped component(s) is / are released is dictated by the binder with the lowest temperature of break down. As discussed below, other properties of the matrix can be afforded by the other binders that may be present in the matrix.

[0076] In some embodiments, the matrix comprises a binder with a breakdown temperature within the range of from about 200°C to about 225°C. In some embodiments, this binder is an alginate, such as sodium alginate, optionally cross-linked with calcium ions, such as calcium alginate formed by combining aqueous calcium chloride to aqueous sodium alginate.

[0077] In some embodiments, the matrix comprises one or more binders having a breakdown temperature within the range of from about 200°C to about 225°C in an amount of at least about 20% by weight (on dry weight basis) of the total binder content. This means that up to 80% of the weight of the binder in the matrix may be one or more further binders having a breakdown temperature that is higher than about 225°C. In some embodiments, the further binder is or includes carboxymethyl cellulose, carrageenan or guar gum. In some embodiments, the further binder is cheaper or more readily available than the alginate binder.

[0078] In some embodiments, the binder is crosslinked in the matrix. For example, the binder may comprise a cross-linkable alginate, such as sodium alginate. Cross-linking may be achieved by exposing sodium alginate to calcium ions.

[0079] In some embodiments, the one or more binders form a gel when mixed with water and other liquid components. The gel or slurry formed by combining the one or more binders and flavour with any other components must then be dried to form the matrix of the aerosol-generating material.

[0080] Any water present in the aerosol-generating material, including in the matrix comprising the highly volatile components, will be released as the material is heated. Indeed, the initial release of steam upon heating aerosol-generating material is referred to as "hot puff" and is a phenomenon that it is desirable to reduce or avoid. As a result, it may be desirable to ensure that the aerosol-generating material does not include significant amounts of water. The water content can also have an adverse effect on the stability of the aerosol-generating material and / or the matrix, and, in some circumstances, the stability of the flavour or other aerosolisable components thereof. Also, the heating of any water in the aerosol-generating material will require the input of energy and so reducing the water content will also reduce the amount of energy required to release the desirable components, including the flavour.

[0081] In some embodiments, the aerosol-generating material and / or the matrix comprising the highly volatile components has a moisture content of no more than about 10% or no more than about 7% w / w. In some embodiments, the moisture content may be from about 2 to about 7% w / w.

[0082] The water content of the aerosol-generating material and / or the matrix comprising the highly volatile components described herein may vary according to, for example, the temperature, pressure and humidity conditions at which the particles are maintained. The water content can be determined by Karl-Fisher analysis or by gas chromatography-thermal conductivity detector (GC-TCD), as known to those skilled in the art. Inclusion of the one or more less volatile aerosolisable components

[0083] There is provided an aerosol-generating material for use in an aerosol provision system, comprising one or more less volatile aerosolisable components having a vapour pressure of less than about 8 Pa and / or a boiling point of above about 180°C. These less volatile components are not provided in the matrix comprising the highly volatile components discussed above. These less volatile aerosolisable components may be flavour components.

[0084] In some embodiments, the one or more less volatile aerosolisable components having a vapour pressure of less than about 8 Pa and / or a boiling point of above about 180°C are not bound or entrapped in any matrix. Rather, these may be incorporated into or onto the aerosol-generating material in unbound or unentrapped form. In a specific example, these components may be included in a composition that is applied to or mixed with the aerosol-generating material. Such a composition comprising the low volatility components may include a liquid solution or suspension such as a casings composition or a flavour composition that may be applied to or blended with one or more constituents of the aerosol-generating material.

[0085] In some embodiments, the one or more less volatile aerosolisable components having a vapour pressure of less than about 8 Pa and / or a boiling point of above about 180°C is bound or entrapped in a second matrix which has different properties to the matrix comprising the highly volatile components. Because the less volatile components will inherently not tend to be aerosolised at temperatures below about 160°C, the second matrix does not need to prevent the release of the less volatile components before the matrix is heated to a temperature above about 180°C. In some embodiments, rather than preventing the release of the less volatile components until heated to the target temperature range of about 180 to about 300°C, the purpose of the second matrix is simply to prevent migration of the less volatile components before use of the aerosolgenerating material in an aerosol provision system.

[0086] In some embodiments, the second matrix releases the bound or entrapped aerosolisable components upon heating to a temperature above about 50°C. This ensures that all of the less volatile components are free of the second matrix when the aerosol-generating material is heated to temperatures at which the aerosol provision system generates an aerosol, that is above about 180°C. In some embodiments, the second matrix comprises one or more binders that are selected to release the bound aerosolisable components upon heating to a temperature above 50°C and preferably below about 175°C.

[0087] In some embodiments, the second matrix does not comprise sodium alginate or calcium alginate.

[0088] In some embodiments, the second matrix comprises one or more of hydroxyethyl cellulose, carrageenan and guar gum.

[0089] In some embodiments, the second matrix is in the form of one or more selected from the group consisting of: beads, tablets, granules, powder or coating.

[0090] Because the second matrix releases the bound or entrapped less volatile components at a temperature below the aerosol generating temperature of the aerosol provision system, the shape and density of the matrix is not expected to significantly influence the extent or rate of release of the less volatile components.

[0091] In some embodiments, at least about 90% of the total aerosolisable component(s) entrapped in the second matrix is released from the matrix and / or aerosol-generating material whilst the matrix is at a temperature below the target temperature range of from about 180 to about 300°C.

[0092] Flavours

[0093] The aerosolisable components included in the aerosol-generating material for use in an aerosol delivery system may include one or more flavours.

[0094] In some embodiments, the aerosol-generating material comprises one or more flavours in a total amount of from about 10 to about 50 wt% (DWB). In some embodiments, the matrix comprising one or more highly volatile components comprises one or more flavours in a total amount of from about 1 to about 50 wt% (DWB). In some embodiments, the total amount of flavour in the aerosol-generating material and / or the matrix is from 20 to 40 wt% (DWB). In some embodiments, the total amount of flavour in the aerosol-generating material and / or the matrix is at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, or at least about 40 wt% (DWB). Additionally or alternatively, the total amount of flavour in the aerosol-generating material and / or the matrix is no more than about 50 wt%, no more than about 45 wt%, no more than about 40 wt%, no more than about 35 wt%, no more than about 30 wt%, no more than about 25 wt%, no more than about 20 wt%, or no more than about 15 wt% (DWB).

[0095] In some embodiments, one or more flavours may be included in the aerosolgenerating material, comprising a mixture of flavour components, some of which are highly volatile with a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C, and some of which are less volatile with a vapour pressure of less than 8 Pa and / or a boiling point of below 180°C.

[0096] As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, Wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and / or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder. In some embodiments, the flavour comprises menthol, spearmint and / or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and / or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis.

[0097] In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucalyptol, WS-3.

[0098] In some embodiments, at least one of the highly volatile aerosolisable components included in the matrix is not menthol.

[0099] In some embodiments, the matrix comprises two or more highly volatile components having different boiling points. The provision of these components in the matrix of the aerosol-generating material means that they are not released according to their boiling points, but instead they are released according to the temperature at which the binder decomposes.

[0100] Where a hydrophobic flavour is included in a matrix, it may be necessary to also include a surfactant or emulsifier to the aqueous slurry to allow the formation of a stable oil-in-water emulsion as a precursor to the dried matrix.

[0101] Aerosol-former material

[0102] In some embodiments, the aerosol-generating material for use in an aerosol delivery system comprises one or more aerosol former materials. The aerosol-former material may comprise one or more constituents capable of forming an aerosol.

[0103] In some embodiments, the aerosol-generating material and / or the matrix comprising the highly volatile components and / or, when present, the matrix comprising the less volatile components comprises one or more aerosol-former materials in a total amount of up to about 60 wt% (DWB). In some embodiments, the total amount of aerosol former in the aerosol-generating material and / or matrix is from about 20 to about 40 wt% (DWB).

[0104] In some embodiments, the aerosol-generating material and / or matrix comprises aerosol-former material in a total amount of at least about 1 wt%, at least about 5 wt%, at least about 10 wt%, at least about 15 wt%, at least about 20 wt%, at least about 25 wt%, at least about 30 wt%, at least about 35 wt%, at least about 40 wt%, at least about 45 wt%, at least about 50 wt%, or at least about 55 wt% on a dry weight basis. Additionally or alternatively, the aerosol-generating material and / or matrix comprises aerosol-former material in an amount of up to about 60 wt%, up to about 55 wt%, up to about 50 wt%, up to about 45 wt%, up to about 40 wt%, up to about 35 wt%, up to about 30 wt%, up to about 25 wt%, or up to about 20 wt% on a dry weight basis. In some embodiments, the aerosol-generating material comprises from about 20 to about 40 wt% aerosol-former material on a dry weight basis.

[0105] The aerosol-former material may be, for instance, a polyol aerosol generator or a nonpolyol aerosol generator. It may be a solid or liquid at room temperature, but preferably is a liquid at room temperature. In some embodiments, the aerosol-former material may comprise one or more of glycerine, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso- Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

[0106] In some embodiments, the aerosol-former material comprises one or more polyhydric alcohols, such as propylene glycol, triethylene glycol, 1,3-butanediol and glycerin; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and / or aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. In some embodiments, the aerosol-former material comprises one or more compounds selected from erythritol, propylene glycol, glycerol, vegetable glycerine (VG), triacetin, sorbitol and xylitol. In some embodiments, the aerosol-former material comprises, consists essentially of, or consists of, glycerol. In a preferred embodiment, the aerosol-former material consists of glycerol.

[0107] A combination of two or more aerosol-former materials may be used, in equal or differing proportions.

[0108] Excipient In some embodiments, the aerosol-generating material and / or the matrix further comprises one or more excipients, also referred to as fillers, diluents or bulking agents.

[0109] Suitable excipients include mannitol, sucrose, trehalose, lactose, sorbitol, raffinose, maltose, Dextran 10, Dextran 70, Dextran 90, maltodextrin, gelatin, agar, cyclodextrin, PEG 2000-6000, (PVP 10k), as well as cellulose and cellulose derivatives, such as ground cellulose and microcrystalline cellulose.

[0110] In some embodiments, the aerosol-generating material comprises one or more excipients in an amount of from about 0 to about 30 wt%, or from about 10 to about 20 wt% on a dry weight basis

[0111] In some embodiments, the aerosol-generating material may comprise at least about 1 wt%, at least about 2 wt%, at least about 5 wt%, at least about 8 wt%, or at least about 10 wt% excipient on a dry weight basis. Alternatively or additionally, the liquid composition may comprise up to about 30 wt%, up to about 25 wt%, up to about 20 wt%, up to about 15 wt%, or up to about 10 wt% excipient on a dry weight basis.

[0112] Manufacturing aerosol-generating material

[0113] In addition to providing the highly volatile components bound in a matrix comprising one or more binders that are selected to release the flavour upon heating to a target temperature range, the process used to prepare said matrix has also been found to have an impact on the extent to which the highly volatile component(s) is / are bound or trapped in the matrix and subsequently released upon heating, i.e. the yield.

[0114] According to an aspect of the invention, a method for preparing an aerosol-generating material is provided, comprising : forming a slurry comprising one or more aerosolisable components having a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C and one or more binders; solidifying the slurry; and freeze drying the solidified slurry to form a matrix; and combining the matrix with one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C.

[0115] Thus, in order to form the matrix comprising one or more highly volatile components of the present invention, a slurry is first formed. In some embodiments, this comprises the one or more binder and the one or more highly volatile components, such as flavour components, as well as any other optional components, such as the aerosol former material or excipient discussed above. In some embodiments, the slurry also includes added water.

[0116] Any water may be included to enhance the homogenous mixing of the slurry components to ensure that portions of the slurry will have a consistent make up. Water is also required to hydrate the binder. However, the addition of more water than is required should be avoided as this water will be removed during the drying step and the greater the water content, the longer the drying step and the more energy it is likely to require. In some embodiments, the slurry has a starting water content of about 40 wt%. In such embodiments, the starting material is more like a dough than a watery slurry. The water content may be as high as 92 wt%. However, where the water content in the starting material is higher, flavour retention in the end product will be lower.

[0117] In some embodiments, the slurry comprises: from about 5 to about 10 wt% binder on a wet weight basis (WWB); from about 10 to about 50 wt% flavour (WWB); and from about 0 to about 90 wt% water. Optionally, the slurry may also comprise from about 10 to about 50 wt% aerosol-former material, and / or from about 1 to about 15 wt% excipient (WWB).

[0118] Next, the slurry is solidified. In some embodiments, a plurality of portions of the slurry are solidified to form solid or semi-solid shaped bodies that are then dried by freeze-drying.

[0119] In some embodiments, the portions of slurry are solidified by rapid pre-freezing (also referred to herein as "snap frozen") by exposure to extreme cold. For example, droplets or a jet (for example, an intermittent jet) of the slurry may be dispensed into liquid nitrogen. The droplets or strands of slurry will freeze very rapidly upon exposure to a temperature in the region of -196°C. This mode of solidifying the slurry may be used for binders that do not cross-link or are difficult to cross-link, such as carboxymethyl cellulose. Pre-freezing may also be used as an alternative to crosslinking, if desired.

[0120] The size of the resultant frozen particles may be adjusted by adjusting the size of the droplets or jets that are dispensed. In other embodiments, the portions of the slurry may be created using a mould. In such embodiments, at least one surface of the shape created will be flat.

[0121] In some embodiments, droplets are formed with a volume of from about 1 to about 50 pl. In some embodiments, the volume of the droplets or the average (mean) volume is at least about 1 pl, at least about 5 pl, at least about 10 pl, at least about 15 pl, at least about 20 pl, at least about 25 pl, at least about 30 pl, at least about 35 pl or at least about 40 pl. Additionally or alternatively, in some embodiments, the volume of the droplets or the average (mean) volume is no greater than about 50 pl, about 45 pl, about 40 pl, about 35 pl, about 30 pl, about 25 pl, about 20 pl, or no greater than about 15 pl.

[0122] In some embodiments, the droplets or jets are pre-frozen at atmospheric pressure.

[0123] The slurry tends to expand when pre-frozen. The size of the frozen particles may increase by from about 5 to about 10% compared to the liquid form. Some crystallisation may also be observed within the frozen particles.

[0124] Additionally or alternatively, the portions of slurry are solidified or partially solidified by cross-linking one or more binder within the slurry by exposure to a cross-linking agent. For example, droplets or jets of the slurry may be dispensed into a liquid bath comprising the cross-linking agent. The droplets or jets of slurry will solidify rapidly upon exposure to the cross-linking agent, forming gel beads or strands. Alternatively, the cross-linking agent may be applied to the portion of slurry, for example by being sprayed onto a surface of the portion. The portion of slurry may be held in a mould to form a shaped gel particle upon cross-linking. In other embodiments, the slurry may be provided in the form of a layer or film to form a gel sheet or film.

[0125] It is hypothesised that cross-linking the binder and / or controlling the extent to which the binder is cross-linked, may be a means to control the porosity of the gel and the resultant dried matrix.

[0126] The drying methods used to dry the at least partially solidified slurry may be any suitable freeze-drying process using known small or large scale freeze-drying equipment.

[0127] Freeze-drying, also known as lyophilisation or cryodesiccation, is a process in which the slurry is frozen, the temperature lowered and the water is removed via sublimation under reduced pressure conditions. Without wishing to be bound by any particular theory, it is believed that the low processing temperatures and rapid water loss via sublimation avoid changes in the slurry structure, appearance and characteristics. This process preserves the structure of the slurry and reduces the loss and decomposition of the highly volatile components.

[0128] Freeze drying may be conducted at a temperature of from about -35 to about -50°C. The freeze drying may be carried out at a pressure of from about 30 to about 40 pbar.

[0129] The matrix formed by freeze drying has a lower water content than the at least partially solidified portion of slurry. The residual moisture content of the matrix may be reduced to less than about 15% and may be from about 5 to about 14% or from about 7 to about 12%, as measured by gas chromatography-thermal conductivity detector (GC-TCD) or Karl Fischer measurement. A low moisture content helps to avoid or manage the phenomenon referred to as "hot puff" in aerosol-generating products.

[0130] The drying of the slurry to form the matrix may result in a reduction in water content of at least about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, about 90 wt%, about 95 wt%, or at least about 98 wt%.

[0131] In some embodiments, the slurry is freeze-dried for a period of from about 48 hours to about 120 hours. In some embodiments, the freeze drying is carried out for a period of at least about 48, 50, 55, 60, 65, 70, 75, 80, 85, 90 or at least about 95 hours. Additionally or alternatively, the freeze drying is carried out for a period of no longer than about 120, 110, 100, 95, 90, 85, 80, 75, 70, 65 or no longer than about 60 hours. The smaller the diameter of the beads or strands being freeze dried, the shorter the drying period. Therefore, freeze-drying periods of as low as 24 hours or even 12 hours may be possible.

[0132] In some embodiments, the freeze-dried material undergoes a secondary drying step.

[0133] The first drying step, in which the slurry is dried by freeze drying, removes the unbound water in the at least partially solidified portion of slurry. The optional secondary drying step may be carried out to remove the chemically bound water and thereby further reduce the moisture content of the freeze-dried material. In some embodiments, the secondary drying step may comprise gradually increasing the temperature of the freeze-dried material to a temperature of from about +15°C to about +25°C, for example, to a temperature of about +20°C and then holding the material at that temperature for a period of time. The temperature at which the freeze-dried material is held during the secondary drying step must not be higher than room temperature, in order to avoid driving off desirable volatile components of the slurry that have been retained as a result of the solidifying and freeze drying steps.

[0134] In some embodiments, the endpoint of the secondary drying may be determined by vacuum gauge which is used to determine when no more water is being removed (i.e., the water release plateaus). In some embodiments, this may be when the moisture content is less than about 10%, as measured by Karl Fisher analysis.

[0135] In some embodiments, the freeze-dried material may be held at the elevated temperature for a period of from about 10 to about 25 hours.

[0136] Dried

[0137] In some embodiments, the matrix comprising one or more highly volatile components is in the form of shaped particles. The shaped particles formed by at least partially solidifying portions of the slurry prior to freeze-drying have a size, geometry and make up that is readily controlled as a result of the manufacturing process discussed above.

[0138] The geometry of the shaped particles of the matrix may be controlled by the method used to form the shaped portion of slurry that are at least partially solidified. As discussed above, such methods may involve dispensing droplets or jets, or using moulds.

[0139] In addition, the freeze-drying process leads to some slight shrinkage of the shaped portion. The shrinkage observed occurs as a result of the removal of water from the shaped portion and so the greater the water content in the slurry (and the shaped portion), the greater the shrinkage that will be observed following drying. This shrinkage may result in a reduction in size or volume of from about 5 to 10%. The specific extent of the shrinkage will be dependent on the shape and size of the portion.

[0140] Where the shaped portion has been pre-frozen, this step may, as discussed above, result in an initial expansion. The subsequent shrinkage during freeze-drying may result in approximate return to the size before the pre-freezing. In some embodiments, the shaped particles of the matrix are beads that may be generally spheroid in shape. In some embodiments, the beads have the shape of a slightly shrunken sphere, i.e., they may have a slightly uneven surface morphology.

[0141] The diameter of the beads will be influenced by the volume of the droplet formed from the slurry and by the solids content in the slurry. Some shrinkage is observed during drying, relative to the size of the frozen droplets.

[0142] The manufacturing process means that the size of the dried beads can be very consistent. In some embodiments, at least about 90% of the dried beads have a diameter that varies by no more than 5% from the mass median diameter of the population. In some embodiments, at least about 95%, at least about 97%, at least about 98% or at least about 99% of the dried beads have a diameter that varies by no more than 5% from the mass median diameter of the population.

[0143] In some embodiments, the dried beads are free-flowing and non-sticky, and this aids handling of the beads.

[0144] In some embodiments, the dried beads have a diameter in the range of from about 2 mm to about 5 mm. Optionally, the diameter may be at least about 2 mm, at least about 2.5 mm, at least about 3 mm, at least about 3.5 mm, at least about 4 mm or at least about 4.5 mm. Alternatively or additionally, the diameter is no greater than about 5 mm, no greater than about 4.5 mm, no greater than about 4 mm, no greater than about 3.5 mm, no greater than about 3 mm or no greater than about 2.5 mm. In some embodiments, the dried beads have a mean diameter of from about 2.5 to about 3 mm.

[0145] Beads with a smaller diameter have a greater surface area to volume ratio and they may therefore exhibit more rapid release of flavour components compared to beads with a larger diameter.

[0146] In some embodiments, the size and shape of the portions of slurry are selected to provide a desired release profile of the one of more highly volatile components. In general, beads with a smaller diameter or size will release the components more quickly upon use and for a shorter period of time. Beads with a larger diameter or particle size will release the components more gradually and for a longer period. In some embodiments, beads of different sizes may be selected and combined to provide a release profile that starts rapidly upon commencement of use and continues over an extended period of use.

[0147] In some embodiments, it may be desirable for the beads to have an average particle size or diameter of no greater than about 5 mm, of no greater than 4 mm, of no greater than about 3 mm, or of no greater than about 2 mm, when measured by sieving. In some embodiments, the beads have a diameter of from about 2 to about 3 mm. This may be assessed by sieving or by measurement using a QuickScope™ instrument for approximating the diameter of a roughly spherical form.

[0148] In some embodiments, the dried beads have a volume in the range of from about 0.005 to about 0.02 cm3. In some embodiments, the dried beads have a mean volume of at least about 0.008 cm3, at least about 0.009 cm3, at least about 0.01 cm3, and / or a mean volume of no greater than about 0.015 cm3, no greater than about 0.014 cm3, no greater than about 0.013 cm3, or no greater than about 0.012 cm3.

[0149] In some embodiments, the dried shaped particles have flat shapes, such as thin strips or discs. In some embodiments, the flat shapes have a thickness of from about 0.05 mm to about 0.25 mm. In some embodiments, the flat shapes have a length of from about 10 mm to about 40 mm. In some embodiments, the flat shapes have a width of from about 0.5 mm to about 1.5 mm.

[0150] The chemical makeup of the dried shaped particles will be controlled by the chemical makeup of the slurry. The drying process is selected to mitigate or prevent the loss of desirable components from the slurry, including in particular the loss of the highly volatile flavours. In some embodiments, the drying process removes essentially only water from the at least partially solidified slurry. In other embodiments, some water- soluble components are lost in small amounts. Some high volatility components are also vulnerable to loss during the drying process, although the drying parameters are selected to keep such losses to a minimum.

[0151] The inventors have found that the inclusion of an excipient may help to improve the stability of the composition during the drying process, especially when the slurry comprises glycerol as an aerosol-former material. This may be as a result of the excipient increasing the collapse temperature of the formulation. So-called "puffing" or significant expansion of the slurry portions may occur as they are freeze dried, indicating a "boiling" of the slurry composition. This boiling may be reduced or prevented by the addition of an excipient such as dextran (for example, Dextran 70K). In some embodiments, the amount of excipient included may be reduced, or the excipient may be completely omitted. This may be possible without compromising the stability of the composition during drying by including the aerosol former in smaller amounts, and / or by heavily diluting the aerosol former, for example in embodiments where the slurry comprises up to 90% or even up to 92% water.

[0152] It may be desirable to store the aerosol-generating material comprising the dried matrix in a controlled, dry environment, to reduce the likelihood of the material absorbing moisture from its immediate environment. Ideally, the aerosol-generating material will be protected from moisture until it is to be used by a consumer.

[0153] Use of the aerosol-generating material

[0154] The aerosol-generating material disclosed herein may be used in a variety of different delivery systems, in order to deliver flavour to a user.

[0155] As used herein, the term "delivery system" is intended to encompass systems that deliver at least one substance to a user, and includes: combustible aerosol provision systems, such as cigarettes, cigarillos, cigars, and tobacco for pipes or for roll-your-own or for make-your-own cigarettes (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco substitutes or other smokable material); non-combustible aerosol provision systems that release compounds from an aerosol-generating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials; and aerosol-free delivery systems that deliver the at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

[0156] In some embodiments, the aerosol-generating material is used in a delivery system without significant further processing. For example, the particle size may not need to be adjusted or selected.

[0157] Aerosol-generating material The aerosol-generating material of the present invention is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way.

[0158] In some embodiments, the aerosol-generating material is for use in a "noncombustible" aerosol provision system. According to the present disclosure, a "non-combustible" aerosol provision system is one where a constituent aerosolgenerating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

[0159] In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

[0160] In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosolgenerating material is not a requirement.

[0161] In some embodiments, the non-combustible aerosol provision system is an aerosol-generating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating system.

[0162] In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and an aerosol-generating material. The aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.

[0163] Typically, the non-combustible aerosol provision system may comprise a non- combustible aerosol provision device and a consumable for use with the non- combustible aerosol provision device.

[0164] In some embodiments, the disclosure relates to consumables comprising aerosolgenerating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.

[0165] In some embodiments, the non-combustible aerosol provision system, such as a non-combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic power source.

[0166] In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and / or an aerosol-modifying agent.

[0167] In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a wrapper, a filter, a mouthpiece, and / or an aerosol-modifying agent.

[0168] The aerosol-generating material of the present disclosure may be stable at a range of temperatures, so that it may be stored and / or transported for a much longer period without deterioration of the properties of the aerosol. A low water content also inhibits microbial growth.

[0169] In some embodiments, a consumable comprises from about 5 to about 50 mg of the aerosol-generating material, from about 5 to about 25 mg, or from about 10 to about 15 mg of the aerosol-generating material.

[0170] In some embodiments, a consumable comprises from 1 to 20 beads of the matrix comprising highly volatile component(s), or from about 5 to 10 beads of said matrix.

[0171] In some embodiments, a consumable comprises from about 1 mg to about 25 mg of flavour components, including both highly volatile flavour component(s) and less volatile flavour component(s). In some embodiments, the consumable comprises from about 5 to about 20 mg, or from about 5 to about 10 mg of flavour components. In some embodiments, the flavour included in a consumable provides flavour in an amount equivalent to the top flavour applied to a commercially available demi-slim format consumable.

[0172] In some embodiments, the matrix comprising one or more highly volatile components, and the less volatile components, may be combined with one or more other materials to form the aerosol-generating materials of the present invention. For example, the aerosol-generating material may further comprise tobacco material, or other plant or botanical material. The different materials may be provided separately or together, for example as a mixture or blend.

[0173] Incorporation into an aerosol-generating device.

[0174] In some embodiments, the aerosol-generating material is provided in a consumable.

[0175] A consumable is an article comprising aerosol-generating material, part or all of which is intended to be consumed during use by a user. A consumable may comprise one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generation area, a housing, a wrapper, a mouthpiece, a filter and / or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor. The consumable may be any shape or size that is appropriate to the aerosol provision device. In some embodiments, the consumable is a rod shape.

[0176] In some embodiments, the aerosol-generating material is provided in an aerosolgenerating device. Advantageously, the aerosol-generating material may be used directly as a flavoured aerosol source and, in some embodiments, is directly heated without burning to provide an inhalable flavoured aerosol. Heating the aerosolgenerating material may aerosolise components of the material, for example the flavour components and any aerosol-former material. The aerosol-generating material and / or the consumable may be stored in reduced humidity conditions, for example less than about 30% humidity, prior to use. An additional benefit of the aerosol-generating material being used directly as an aerosol source is that the low water content reduces issues associated with "hot puff", which are known in the art.

[0177] Figure 1 is a side-on cross-sectional view of a consumable or article 1 for use in an aerosol delivery system. The article 1 comprises a mouthpiece segment 2, and an aerosol generating segment 3.

[0178] The aerosol generating segment 3 is in the form of a cylindrical rod and comprises an aerosol-generating material 4 comprising a population of shaped particles of matrix as disclosed herein. For example, the shaped particles can be any of the particles or beads discussed herein.

[0179] Although described above in rod form, the aerosol-generating segment 3 can be provided in other forms, for instance a plug, pouch, or packet of material within an article.

[0180] The mouthpiece segment 2, in the illustrated embodiment, includes a body of material 5 such as a fibrous or filamentary tow.

[0181] The rod-shaped consumable 1 further comprises a wrapper 6 circumscribing the mouthpiece segment 2 and aerosol generating segment 3, such as a paper wrapper.

[0182] Figure 2 shows an example of a non-combustible aerosol provision device 100 for generating aerosol from an aerosol-generating medium such as the aerosol-generating material of a consumable 110, as described herein. In broad outline, the device 100 may be used to heat a replaceable article 110 comprising the aerosol-generating medium, for instance an article 1 as illustrated in Figure 1 or as described elsewhere herein, to generate an aerosol or other inhalable medium which is inhaled by a user of the device 100. The device 100 and replaceable article 110 together form a system.

[0183] The device 100 comprises a housing 102 (in the form of an outer cover) which surrounds and houses various components of the device 100. The device 100 has an opening 104 in one end, through which the article 110 may be inserted for heating by a heating assembly. In use, the article 110 may be fully or partially inserted into the heating assembly where it may be heated by one or more components of the heater assembly. The device 100 of this example comprises a first end member 106 which comprises a lid 108 which is moveable relative to the first end member 106 to close the opening 104 when no article 110 is in place. In Figure 2, the lid 108 is shown in an open configuration, however the lid 108 may move into a closed configuration. For example, a user may cause the lid 108 to slide in the direction of arrow "B".

[0184] The device 100 may also include a user-operable control element 112, such as a button or switch, which operates the device 100 when pressed. For example, a user may turn on the device 100 by operating the switch 112.

[0185] The device 100 may also comprise an electrical component, such as a socket / port 114, which can receive a cable to charge a battery of the device 100. For example, the socket 114 may be a charging port, such as a USB charging port.

[0186] Examples

[0187] The following are illustrative examples of the compositions and processes described herein.

[0188] Example 1

[0189] Samples of matrix material were prepared from slurries with the following compositions, with the amounts given as percentage by weight on a dry weight basis, and water added to provide the stated solids content:

[0190] These slurries were dispensed as droplets into a bath comprising a 14% aqueous calcium formate solution. The calcium ions present once the calcium formate is dissolved in water act as a cross-linking agent, causing the alginate in the slurry to instantly cross-link to form gel beads. These gel beads were uniform in size and spherical shape. The gel beads were separated from the calcium solution and were rinsed with purified water to remove as much of the calcium formate as possible. Any remaining calcium formate tends to recrystallise on the surface of the beads. The gel beads were then freeze dried. First, the beads were cooled to the freeze- drying temperature of -50°C over a period of 10 minutes. Then, the gel beads were held at -50°C and a pressure of 40 pbar for a period of 1580 minutes.

[0191] Next, the freeze-dried beads underwent a secondary drying step. Over a period of 140 minutes, the temperature of the freeze dried beads was adjusted to 20°C and the pressure adjusted to 100 pbar. Then, the beads were held at this temperature and pressure for a further period of 460 minutes.

[0192] Finally, the beads were stored in stoppered vials filled with nitrogen.

[0193] Post-drying, the beads were white in appearance and uniform in size and generally spherical shape. The beads of sample 3 appeared to have a more variable shape. It appeared that the beads were covered with an outer layer of calcium formate salt. This can be avoided by rinsing the gel beads (multiple times) after they have been removed from the calcium formate bath and before freeze-drying.

[0194] The water content of the dried beads was determined using oven Karl Fischer titration using an oven temperature of 110°C and the results (an average of three readings for each sample) were as follows:

[0195] Mechanical strength analyses showed that Sample 1 was the most robust sample with the highest stress at fracture point. Sample 3 was brittle, with more cracks observed.

[0196] Example 2

[0197] The samples produced in Example 1 were heated and the release of various flavour compounds was monitored.

[0198] Release from the freeze-dried sample beads was compared to release from controls (referred to as "US-Neat" and "UK-Neat") in the form of non-encapsulated "free" flavour prepared in propylene glycol.

[0199] The samples and controls were heated gradually and then held at 300°C in a Thermal Desorption Unit (TDU) linked to a Mass Spectrometer Detector (MS) using deactivated fused silica tubing. TDU-MS analysis was conducted using a multi-mode gas chromatography (GC) inlet using the following parameters: 35°C to 300°C ramped at 5°C / min and then held at 300°C for 30 minutes. The GC oven was held isothermally at 300°C to ensure thermal transfer from the TDU to the MS. This showed how different compounds were released as the temperature increased.

[0200] The results are shown in the chromatograph results of Figures 3A to 4E.

[0201] Figures 3A to 3G each show the release of one compound from each of the controls and samples. In Figure 3A, the compound is ethyl butyrate (compound 1). In Figure 3B, the compound is ethyl-2-methyl butyrate (compound 2). In Figure 3C, the compound is ethyl hexanoate (compound 5). In Figure 3D, the compound is propylene glycol (compound 6). In Figure 3E, the compound is 0-ionone (compound 7). In Figure 3F, the release of two closely related compounds is shown, namely y- undecalactone and y-decalactone (compounds 8 and 9). In Figure 3G, the compound is raspberry ketone (compound 10).

[0202] Figures 4A to 4E each show the release of all of the aforementioned compounds from one of the controls or samples. Figure 4A shows the release from the liquid flavour control referred to as US-Neat. Figure 4B shows the release from the liquid flavour control referred to as UK-Neat. Figure 4C shows the release from Sample 1 of

[0203] Example 1 (referred to as Fl-100%). Figure 4D shows the release from Sample 2 of

[0204] Example 1 (referred to as F2-80%). Figure 4E shows the release from Sample 3 of Example 1 (referred to as F3-50%).

[0205] As can be seen from the results, the peak release of the various compounds from the controls and samples was measured as follows:

[0206] These results clearly show that the provision of the flavour bound in a matrix controls the temperature at which the flavour is released. Regardless of the boiling point of the compound in question, the samples of the matrix material controlled release to generally within the range of about 175 to about 260°C. This is clearly closely related to the break down temperature of the binder.

[0207] In contrast, where the flavour was not bound in a matrix of binder, the release of the flavour occurred at much lower temperatures and was more aligned to the boiling point and vapour pressure of the compound in question.

[0208] The release data demonstrates that those flavour components with a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C do not benefit from being bound or entrapped in the matrix. Further, data shows that a greater proportion of these less volatile components are released when they are not provided in the matrix.

[0209] Example 3

[0210] To assess the performance of matrix-bound flavours in a consumable for use in an aerosol-generating system, samples were created incorporating flavours in liquid or bead form into commercial or handmade consumables corresponding to commercially available consumables sold as Neostiks for use in the dual heating zone gio™ heating devices.

[0211] The gio™ device has two heating zones that activate independently on use. The Neostik consumables have two corresponding zones of aerosol generating material, Zone 1 located 25-34 mm from the distal end of the consumable and Zone 2 located 8 to 17 mm from the distal end. The so-called "Dual Zone" samples were prepared with the flavour beads in both zones of aerosol generating material, with three flavour beads in Zone 1 and three flavour beads in Zone 2. The so-called "Zone 2" samples had all six flavour beads located in Zone 2.

[0212] Samples as set out in the table were prepared, each having a target flavour loading of

[0213] 4.16 mg. Samples 1, 2, and 3 included the Samples 1, 2, and 3 flavour beads prepared according to Example 1.

[0214] The 'hand spike' samples were created by spiking 25 pl of flavour solution directly into the tobacco rod of commercially produced Bright tobacco Neostiks. The bead samples were prepared using the same Bright tobacco material. For each sample, ten prototype sticks were produced (except Sample 3 Zone 2, for which only 6 sticks were produced).

[0215] The samples were heated using a gio™ device. In use, Heating Zone 1 of the device is active for the entirety of the 4-minute session. Heating Zone 2 is only active for the last 2 minutes of the session.

[0216] Aerosol was collected using a Cerulean SM-450 linear smoke machine. The smoke regime used was 55 mL puff volume, 2 second puff duration, 30 second puff interval, and bell-shaped puff profile (55-2-30 Bell). The aerosol collection train used was one 44 mm Cambridge filter pad followed by a single impinger filled with 5 mL IPA w / ISTD (ISTD: ~5 pg / mL d -quinoline). This collection train was determined to capture >90% of all analytes of interest. The timing of starting the smoke run on the smoke machine and starting the gio™ device was done in such a manner that the first puff was taken as soon as the device buzzed it was ready for smoking (after its warm-up period). Taking the first puff as soon as the device was ready, coupled with a 4-minute run time and a 30 second interval between puffs allowed nine individual puffs to be collected for each replicate. For puff-by-puff analysis, nine individual aerosol collection trains were assembled to collect one puff per stick each. One collection puff was collected, followed by one clearing puff for each stick smoked. A total of three sticks were smoked for each replicate, with the same aerosol collection trains being used for each puff. There was a ten-minute device cooldown period between each stick smoked. The gio™ device was fully charged in-between each replicate and sample.

[0217] The results showed that when the flavour is applied directly onto the tobacco substrate (hand spike samples), the most volatile compounds (vapor pressure > 1 Torr@25°C) are released very early and are essentially depleted by puff 4, while the non-volatile compounds take around 3-4 puffs before they start exiting the stick.

[0218] The graph of Figure 5 shows the puff-by-puff data for the release of the volatile flavour compound ethyl butyrate. The hand spike sample sees the rapid and almost immediate release of ethyl butyrate, with a spike in release on puff 1 and very low levels of release in puffs 4 and after. In contrast, the Sample 1 Dual Zone and Sample 1 Zone 2 results show delayed release of this volatile flavour compound, with release from puff 4 to puff 9 for the Dual Zone sample and a higher level of release but delayed until puff 7 for the Zone 2 sample. Similar patterns of release were observed for all of the volatile flavour compounds.

[0219] The graphs of Figures 6A and 6B show the puff-by-puff data generated by heating Sample 1 Dual Zone and Sample 1 Zone 2, respectively. The solid lines represent different flavour compounds within the flavour composition. The dotted line shows the release of nicotine. The left axis is the amount of analyte (pg) and the right axis is the amount of nicotine (pg).

[0220] The data show that the inclusion of the matrix-bound flavour in bead form delayed the release of the most volatile flavours until puff 4. There was a reduction in the total amount of non-volatile flavours that were delivered. Release of the volatile flavours from the Dual Zone samples occurred during puffs 4 to 9. Release of the volatile flavours from the Zone 2 samples was delayed until puffs 7, 8, and 9. The pattern of flavour release was the same for the Sample 1, 2 and 3 beads.

[0221] Once again, the data showed that the provision of the flavour bound in a matrix controls the temperature at which the flavour is released. Regardless of the boiling point of the compound in question, the samples of the solid flavour-releasing material of the invention controlled release to the target temperature range determined by the temperature art which the binder releases the flavour.

[0222] The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only and are not exhaustive and / or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein are not to be considered limitations on the scope of the invention as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

Claims1. An aerosol-generating material for use in an aerosol provision system, comprising : one or more aerosolisable components having a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C bound in a matrix comprising one or more binders, wherein the one or more binders are selected to release the bound aerosolisable components upon heating to a target temperature; and one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C that are not bound in said matrix.

2. An aerosol-generating material as claimed in claim 1, wherein the one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C are not bound in any matrix.

3. An aerosol-generating material as claimed in claim 1, wherein the one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C are bound in a second matrix which releases the bound aerosolisable components upon heating to a temperature above about 50°C.

4. An aerosol-generating material as claimed in claim 3, wherein the second matrix is in the form of one or more selected from the group consisting of: beads, tablets, granules, powder or coating.

5. An aerosol-generating material as claimed in any one of claims 1 to 4, wherein the one or more binders are selected to release the bound aerosolisable components upon heating to a target temperature range from about 180 to about 300°C.

6. An aerosol-generating material as claimed in any one of claims 1 to 5, wherein the binder comprises sodium alginate or calcium alginate.

7. An aerosol-generating material as claimed in any one of claims 1 to 6, wherein the aerosol-generating material further comprises tobacco material or a tobacco extract.

8. An aerosol-generating material as claimed in any one of claims 1 to 7, wherein the aerosolisable components are flavour components selected to complement and / orenhance the tobacco flavour of the aerosol generated from the aerosol-generating material.

9. An aerosol-generating material as claimed in claim 8, wherein the aerosolisable components are flavour components that do not provide the aerosol with a distinctive non-tobacco flavour.

10. An aerosol-generating material as claimed in claim 9, wherein the aerosolisable components do not include menthol.

11. An aerosol-generating material as claimed in any one of claims 1 to 10, wherein the matrix comprising one or more binders selected to release the bound aerosolisable components upon heating to a target temperature range from about 180 to about 300°C is in the form of substantially spherical beads.

12. An aerosol-generating material as claimed in claim 11, wherein the beads have a mean diameter of from about 2 to about 5 mm.

13. An aerosol-generating material as claimed in any one of claims 1 to 12, wherein the binder is cross-linked.

14. An aerosol-generating material as claimed in any one of claims 1 to 13, further comprising an aerosol-former material.

15. An aerosol-generating material as claimed in claim 14, comprising from about 0.1 to about 60 wt% aerosol-former material.

16. An aerosol-generating material as claimed in claim 14 or claim 15, wherein the aerosol-former material comprises glycerol and / or propylene glycol.

17. An aerosol-generating material as claimed in any one of claims 14 to 16, wherein the matrix comprises substantially no aerosol former material.

18. An aerosol-generating material as claimed in any one of claims 1 to 17, comprising less than about 10 wt% or less than about 7 wt% water.

19. An article for use in an aerosol provision system, a portion of the article comprising the aerosol-generating material as claimed in any one of claims 1 to 18.

20. A non-combustible aerosol-provision system comprising the aerosol-generating material as claimed in any one of claims 1 to 18 or an article as claimed in claim 19.

21. A non-combustible aerosol-provision system as claimed in claim 20, wherein the system is configured to heat the aerosol-generating material to form a vapour and / or aerosol.

22. A method for preparing an aerosol-generating material as claimed in any one of claims 1 to 18, comprising : forming a slurry comprising one or more aerosolisable components having a vapour pressure of greater than 8 Pa and / or a boiling point of below 180°C and one or more binders; solidifying the slurry; and freeze drying the solidified slurry to form a matrix; combining the matrix with one or more aerosolisable components having a vapour pressure of less than 8 Pa and / or a boiling point of above 180°C.

23. A method as claimed in claim 22, wherein the slurry is solidified to form a solid or semi-solid by cross-linking droplets or a jet of the slurry.

24. A method as claimed in claim 23, wherein the droplets or jet are cross-linked by being dispensed into a bath comprising a cross-linking agent.

25. A method as claimed in claim 23, wherein the slurry is solidified by rapidly freezing droplets or a jet of the slurry.

26. A method as claimed in claim 25, wherein the droplets or jet are frozen by being dispensed into liquid nitrogen.

27. A method as claimed in any one of claims 22 to 26, wherein the solidified slurry is freeze-dried at a temperature of from about -35 to about -50°C at from about 30 to about 40 pbar.

28. A method as claimed in any one of claims 22 to 27, wherein the solidified slurry is freeze-dried for a period of from about 12 or about 24 hours to about 100 hours.

29. A method as claimed in any one of claims 22 to 28, comprising a secondary drying step.

30. A method as claimed in claim 29, wherein the secondary drying step involves increasing the temperature of the freeze-dried solidified slurry to a secondary drying temperature to from about +15°C to about +25°C.

31. A method as claimed in claim 30, wherein the freeze-dried solidified slurry is held at the secondary drying temperature for a period of from about 10 hours to about 25 hours.

32. A method as claimed in any one of claims 22 to 31, wherein the solidified slurry is in the form of one or more beads and / or one or more strands.

33. A method as claimed in claim 32, wherein the solidified slurry is in the form of one or more strands and the one or more strands are cut to form particles or segments before or after freeze-drying.

34. Use of the aerosol-generating material as claimed in any one of claims 1 to 18 to provide sustained release of flavour into an aerosol.

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