Patent Application
20250204579
The invention relates to substrates comprising an aerosol-generating material surrounded by a support, methods of manufacturing the substrates and uses thereof.
Aerosol-generating materials for use in a combustible or a non-combustible aerosol provision system may include a variety of different active substances and/or flavours. Factors such as the concentration of volatile active and/or flavour components in the aerosol generating materials and the stability of the aerosol-generating materials will influence the properties of the aerosol generated.
According to a first aspect of the present invention, there is provided a substrate comprising an aerosol-generating material surrounded by a support, the aerosol-generating material comprising a dried precursor material comprising an extract from a flavour- and/or active-containing plant material.
In some embodiments, the support comprises a sheet and the aerosol generating material is sandwiched between one or more of the sheets.
In some embodiments, the sheet comprises one or more selected from the group consisting of: paper; card; paperboard; cardboard; reconstituted material; a plastics material; a ceramic material; activated carbon; glass; a sintered material; a composite material; a plant-derived material; a fabric or fleece; a fibrous tow; a metal; and a metal alloy.
In some embodiments, the substrate has a rolled configuration.
In some embodiments, the aerosol generating material is distributed within the support.
In some embodiments, the support is a porous material with the aerosol-generating material distributed within the pores. In some embodiments, the support is a fibrous material. In some embodiments, the fibrous material is selected from the group consisting of: a fibrous tow; a non-woven sheet; a porous paper; and a fabric or fleece.
In some embodiments, the support comprises an agglomerated material. In some embodiments, the substrate is an extruded mixture of the support and the aerosol-generating material. In some embodiments, the support comprises tobacco material.
In some embodiments, the support comprises a heating material.
In some embodiments, the substrate does not include a binder applied to adhere the aerosol-generating material to the support.
In some embodiments, a binder is included to adhere the aerosol-generating material to the support, in an amount of from about 0.1 wt % to about 5 wt %, based on the entire weight of the aerosol-generating material. In some embodiments, the binder is selected from the group consisting of: thermoreversible gelling agents; starches; polysaccharides; pectins; celluloses; cellulose derivatives; and alginates.
In some embodiments, the aerosol-generating material further comprises an aerosol-former material.
In some embodiments, the precursor material comprises from about 10 to about 95% by weight extract from a flavour- or active-containing plant material.
In some embodiments, the precursor material comprises from about 1 to about 36 wt % aerosol-former material.
In some embodiments, the precursor material comprises from 0 to about 40% by weight of an excipient.
In some embodiments, the aerosol-generating material comprises from about 45 to about 99% by weight dried extract from the flavour- or active-containing plant material.
In some embodiments, the aerosol-generating material comprises from about 1 to about 34% by weight aerosol-former material.
In some embodiments, the aerosol-generating material comprises from 0 to about 25% by weight of an excipient.
In some embodiments, the plant material is selected from the group consisting of tobacco, eucalyptus, star anise, cocoa and hemp.
In some embodiments, the extract from a flavour- or active-containing plant material is an aqueous extract.
In some embodiments, the extract from a flavour- or active-containing plant material is an aqueous tobacco extract.
In some embodiments, the aerosol-generating material has a water content of no more than about 5% (calculated on a wet weight basis).
In some embodiments, the substrate comprises a moisture impermeable coating surrounding the aerosol-generating material.
In some embodiments, the substrate comprises a sorbent material.
In some embodiments, the substrate is for use in an aerosol provision system.
According to a second aspect of the present invention, there is provided an article comprising an aerosol-generating material surrounded by a support, the aerosol-generating material comprising a dried precursor material comprising an extract from a flavour- and/or active-containing plant material.
In some embodiments, the article comprises the substrate according to the first aspect.
In some embodiments, the article comprises a means to prevent or reduce the absorption of moisture by the dried aerosol-generating material.
In some embodiments, the means is provided separately from the aerosol-generating material and/or substrate.
In some embodiments, the means comprises a film or wrapper comprising a moisture impermeable coating or a sorbent or desiccant material.
According to a third aspect of the present invention, there is provided a non-combustible aerosol-provision system comprising a substrate according to the first aspect.
According to a fourth aspect of the present invention, there is provided a method for providing a substrate comprising: drying a precursor material comprising an extract from a flavour- and/or active-containing plant material and an aerosol-former material to form an aerosol-generating material; and trapping the aerosol-generating material within a support.
In some embodiments, the aerosol-generating material is sandwiched between two layers of support material.
In some embodiments, the aerosol-generating material sandwiched between two layers of support material is rolled.
In some embodiments, the aerosol-generating material is sandwiched between two layers of support material is rolled into the form of a hollow cylinder.
In some embodiments, a binder is added to one or more of the aerosol-generating material and the support before the aerosol-generating material is sandwiched between the layers of support material.
In some embodiments, the aerosol-generating material is distributed within a fibrous support material.
In some embodiments, the method comprises extruding a mixture of the aerosol-generating material and the support material.
In some embodiments, the precursor material is dried by spray-drying or freeze-drying.
Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:
An aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way.
Conventional aerosol-generating materials which comprise tobacco material or a tobacco extract may be used in combustible and non-combustible aerosol-generating devices, including hybrid devices and tobacco heating products, to provide the user with an aerosol with an authentic tobacco taste and texture. One issue encountered with such materials is that the content of the flavour, other volatile compound(s) and nicotine decreases with storage of the aerosol-generating material, dropping off particularly towards the end of the life of the material. This is because the more volatile components, including nicotine and many flavours and aromas, are readily released from the material. Additionally, as the moisture content of the aerosol-generating material increases through moisture absorption, the release of substances such as nicotine and flavours is negatively impacted. Aerosol-generating materials that are produced using conventional methods and procedures commonly need to be used within one to three days of production. There is therefore a need to improve the shelf life of the aerosol generating material.
A further issue associated with conventional aerosol-generating materials comprising tobacco material or a tobacco extract is that the concentration of the desired components such as nicotine and flavours is relatively low. This limits the concentration of these desired components in the aerosol generated. Additionally, this means that a relatively large amount of the aerosol-generating material is needed and, accordingly, high amounts of energy are required to heat the aerosol-generating material in order to release the desired components.
The present invention relates to compositions comprising a dried or dehydrated aerosol generating material formed from an extract from a flavour- and/or active-containing plant material. In some embodiments, the extract is a liquid solution or suspension and it may be dried or dehydrated using a process such as spray-drying or freeze-drying. The dried or dehydrated aerosol generating material may be formed from a precursor material comprising the extract from a flavour- and/or active-containing plant material and an aerosol-former material.
The aerosol-generating material comprising the dried extract from a flavour- and/or active-containing plant material comprises a high concentration of the flavour and/or active, with little or no material that does not contribute to the aerosol generated from the dried aerosol-generating material. As such, small amounts of the aerosol-generating material are sufficient to generate aerosol with desired active and flavour content. Further, the aerosol may be generated with the input of relatively low levels of energy.
An additional benefit of the aerosol-generating material being used as a solid substrate is that the low water content reduces issues associated with “hot puff”, which are known in the art.
In some embodiments, the dried aerosol-generating material has a moisture content of from 0 to about 10%, or from 0 to about 5% (calculated on a wet weight basis), as measured by gas chromatography-thermal conductivity detector (GC-TCD) or Karl Fischer titration. In some embodiments, the moisture content of the dried aerosol-generating material is less than about 3 wt %, for example from about 0 to about 3 wt %, or from about 0.5 to about 2.5 wt %.
Karl Fischer titration is a classic method of chemical analysis for reliably determining the amount of water in a sample, and even just trace amounts. The method can be readily carried out using an automated Karl Fischer titrator. Similarly, the use of GC-TCD is also a well-established method for reliably determining the water content in a sample.
Unless stated otherwise, references to moisture content herein are references to the moisture content as measured by Karl Fischer titration.
The dried aerosol-generating material may be hygroscopic and so measures may need to be taken to ensure that the aerosol-generating material does not absorb moisture during processing, incorporation into a final product and storage in that final product prior to use.
In the present disclosure, the aerosol-generating material is surrounded by a support or support material. The combination of the aerosol-generating material and the support is referred to herein as a substrate. The substrate may be used in an aerosol-provision system to generate an aerosol. The support carries and protects the aerosol-generating material and presents it in a manner suitable for use in an aerosol-provision system. This is a particularly beneficial way to provide the aerosol-generating material as this material is highly concentrated so that only very small amounts are required compared to the conventional aerosol-generating materials.
Further, as the aerosol-generating material is at least partially surrounded by the support, it is at least partially protected from the moisture in the environment. This means that absorption of moisture by the aerosol-generating material is limited and managed.
Thus, a substrate is provided comprising a support surrounding an aerosol-generating material comprising a dried precursor material comprising an extract from a flavour- and/or active-containing plant material.
In some embodiments, the hygroscopic aerosol-generating material has a moisture content of no greater than about 10% or no greater than about 5% (calculated on a wet weight basis), as measured by gas chromatography-thermal conductivity detector (GC-TCD) or Karl Fischer titration. This moisture content of the aerosol-generating material is stable, meaning that the moisture content of the aerosol-generating material is within this range not only when it is first prepared, but also after incorporation into a substrate and following transport and storage. This stable moisture content is observed despite the fact that the hygroscopic aerosol-generating material would rapidly absorb moisture if exposed to the environment, even under “normal” humidity conditions. Indeed, when the aerosol-generating material is described as hygroscopic, this means that it will rapidly absorb water from the surrounding environment to significantly increase its water content. For example, upon exposure of the aerosol-generating material to the environment (for example, upon storage in an open container or the like), the moisture content rapidly increases to above 20% or above 25% (calculated on a wet weight basis), as measured by gas chromatography-thermal conductivity detector (GC-TCD) or Karl Fischer titration.
The supports or support materials used herein surround the aerosol-generating material. This can be achieved using a variety of different support materials and support configurations.
In some embodiments, the support comprises a sheet or is in the form of one or more sheets. To form a substrate, the aerosol generating material is sandwiched between one or more of the sheets. For example, a support sheet may be folded and the aerosol-generating material located between the two or more layers of the folded sheet, so that it is sandwiched between layers of the sheet material. In such a configuration, the aerosol-generating material may be present as a continuous or discontinuous layer, or as portions or units of aerosol-generating material. Further, a significant portion of the aerosol-generating material will be shielded from the environment by the layers of support material and from moisture.
In another possible configuration, the support comprises one or more rolled sheets, with the aerosol-generating material located between layers of the sheet(s). Two such configurations are shown in
In
In
In another embodiment, the support is a crimped and/or gathered sheet material, such as paper. The aerosol-generating material may be included in the form of particles, wherein the particles may or may not be agglomerated. In such embodiments, it may not be necessary for the aerosol-generating material to be glued or adhered to the support, even if it is provided in a particulate form. Rather, in this configuration, particles of aerosol-generating material can be held in place by friction, assisted by the crimped and/or gathered shape of the sheet material which forms gaps and cavities within which the particles may be captured and held. The capturing of the particles will be increased in some embodiments where the crimped and/or gathered sheet is formed into a rod, for example for incorporation into a consumable.
The support sheets used in these embodiments may be flexible or rigid.
In some embodiments, the sheet material may be or may comprise one or more selected from the group consisting of: paper, card, paperboard, cardboard, reconstituted material, a plastics or polymeric material, a ceramic material, a composite material, a plant-derived material, a fabric or fleece, a metal, or a metal alloy.
The sheet used as a support may have a surface that is smooth, or a surface that is rough or porous. A rough or porous surface may be advantageous where the aerosol-generating material is not adhered to the sheet using a binder, or is not provided as a layer bound to the surface of the sheet.
In some embodiments, the aerosol generating material is distributed within the support.
In some embodiments, the support is a porous material and the aerosol-generating material is distributed within the pores. For example, the support may be a fibrous material. Such a fibrous material may be selected from the group consisting of: a fibrous tow, such as a cellulose acetate tow; a non-woven sheet, such as air-laid material such as air-laid paper or other porous paper; and a fabric or fleece.
For example, the support or part thereof may be formed from a rough or porous paper material, such as tipping paper, porous plug wrap, cigarette paper or tea bag paper. The paper may be a porous paper. When an aerosol-generating material is applied to the surface of such a support, the particles may nestle into the pores of the porous paper to provide good adhesion between the solid surfaces of the particles and the paper. In some embodiments, the support surface comprises a paper material, the paper optionally having a weight of from about 20 gsm to about 100 gsm.
In some embodiments, the support is or comprises an air-laid paper. This has a highly porous surface structure and in some embodiments, the aerosol-generating material is applied to the surface of the air-laid paper. In other embodiments, the aerosol-generating material may be added during the manufacture of the air-laid paper, the manufacturing process being a dry process.
In some embodiments, the aerosol-generating material distributed within the support is in particulate form. In other embodiments, the aerosol-generating material is in the form of a single mass located within the support. In some embodiments, the aerosol-generating material is in the form of a coating within the support.
In some embodiments, the aerosol-generating material is added to the porous support as the support material is formed or incorporated into the substrate. For example, where the support is a fibrous tow, this material may be gathered and formed into the desired shape, such as a cylindrical plug. As the tow is gathered, the aerosol-generating material may be added, so that it is embedded in and distributed throughout the support material of the substrate.
In some embodiments, the aerosol-generating material is added to the porous support as the support material is manufactured. For example, where the support material is a non-woven sheet, such as a paper, fabric or reconstituted material (such as a sheet of reconstituted tobacco), the aerosol-generating material may be incorporated into the sheet as it is formed. This may again lead to the aerosol-generating material being embedded in and distributed throughout the support material of the substrate.
In some embodiments, the support comprises an agglomerated material. This means that it is possible to distribute or embed the aerosol-generating material within the agglomerated support material.
In some embodiments, the aerosol-generating material is added to the agglomerated support material as it is manufactured. For example, the support material to be agglomerated is mixed with the aerosol-generating material prior to the agglomeration step. The agglomeration step will then incorporate the aerosol-generating material within the agglomerated support. At least some of the aerosol-generating material will be surrounded by the agglomerated support material, thus being protected from the moisture in the surrounding environment.
In some embodiments, the mixture is agglomerated by extrusion.
In some embodiments, the agglomeration process is dry, i.e. the components to be agglomerated are dry and there is no addition of a liquid component. One such dry agglomeration process is dry extrusion, where the components to be extruded are combined without any additional liquid component. In dry extrusion, the shear forces applied to the extruded composition can be sufficient to cause fusion or binding to form a stable agglomerate.
In other embodiments, a liquid may be added to lubricate the mixture being agglomerated. In some embodiments, water may be added as a processing aid. For example, the presence of water may help to dissolve components of the composition to be agglomerate, and/or it may assist with binding or improve agglomeration. In some embodiments, the liquid may comprise an aerosol-former material. The aerosol-former material may be one of the aerosol-former materials discussed elsewhere herein. Another liquid that may be included to assist agglomeration is a liquid extract from a flavour- and/or active-containing plant material. These liquids may be used in addition to or instead of conventional liquid agglomeration aids.
In some embodiments, the agglomeration process exposes the material to be agglomerated to conditions under which the precursor material may be dried. One such agglomeration process is extrusion, during which the mixture is exposed to heat and high shear forces that can have a drying effect. In such embodiments, the support material to be agglomerated may be mixed with either the (already dried) aerosol-generating material, or with the precursor material, or with a combination of both. The subsequent agglomeration step will dry any precursor material present in the mixture to form the aerosol-generating material.
In some embodiments, the agglomerated support material comprises tobacco material, for example, tobacco material in the form of particles.
The tobacco particles have a size small enough to ensure that multiple such particles can be agglomerated to form a substrate having desired dimensions based upon their intended use. Smaller tobacco particles have a greater surface area to volume ratio and they may therefore exhibit enhanced release of tobacco constituents compared to particles of larger sizes.
In addition, the size of the tobacco particles (and of other particles in the composition to be agglomerated) will have an effect on the porosity and density of the agglomerated structures and the substrates formed therefrom. Thus, in some embodiments, the size of the tobacco particles may be selected to produce an agglomerated structure with the desired porosity, which will have an impact on the release of the tobacco constituents from the tobacco support material as well as the aerosol from the aerosol-generating material which is surrounded by the support.
The extrusion processes used to form the agglomerated structures can be sensitive to the size of the particles within the composition being extruded. Therefore, it may be desirable for the particles in the composition to be extruded, for example including tobacco particles as the support material, to have an average particle size of no greater than about 0.5 mm, or to have an average particle size of no greater than about 0.3 mm, when measured by sieving. In some embodiments, it may be desirable for the particles in the composition to be extruded to have an average particle size of no greater than about 0.5 mm, or to have an average particle size of no greater than about 0.3 mm, when measured by sieving. In some embodiments, the average particle size is within the range of about 0.1 to about 0.4 mm, or in the range of about 0.2 to about 0.3 mm. In some embodiments, at least about 90% of the particles of the composition to be extruded will have a particle size within the range of 0.1 to 0.5 mm. In some embodiments, at least about 90% of the particles of the composition to be extruded will have a particle size within the range of 0.1 to 0.5 mm. In some embodiments, none of the particles in the composition have a particle size greater than 1 mm.
The tobacco material used to form the particles of support material may be any type of tobacco and any part of the tobacco plant, including tobacco lamina, stem, stalk, ribs, scraps and shorts or mixtures of two or more thereof. Suitable tobacco materials include the following types: Virginia or flue-cured tobacco, Burley tobacco, Oriental tobacco, or blends of tobacco materials, optionally including those listed here. The tobacco may be expanded, such as dry-ice expanded tobacco (DIET), or processed by any other means. In some embodiments, the tobacco material may be reconstituted tobacco material. The tobacco may be pre-processed or unprocessed, and may be, for instance, solid stems (SS); shredded dried stems (SDS); steam treated stems (STS); or any combination thereof. The tobacco material may be fermented, cured, uncured, toasted, or otherwise pre-treated.
In some embodiments, the agglomerated support may have an increased surface area by including in the composition to be agglomerated particles of an inert filler material. Suitable inert fillers may be porous or non-porous.
In some embodiments, the composition to be agglomerated does not include a binder or binding additive. In other embodiments, the composition to be agglomerated comprises a binder or binding additive. The binding additive may be selected to assist in the formation of an agglomerated structure by helping to adhere the components in the composition to one another. Suitable binding additives include, for example, starches, polysaccharides, pectins, celluloses, cellulose derivatives such as carboxymethylcellulose, and alginates. Other suitable binders are those discussed elsewhere herein.
In some embodiments, the support consists of or comprises a heating material that comprises one or more materials selected from the group consisting of: an electrically-conductive material, a magnetic material, and a magnetic electrically-conductive material. In some embodiments, the heating material may comprise a metal or a metal alloy. In some embodiments, the heating material may comprise one or more materials selected from the group consisting of: aluminium, gold, iron, nickel, cobalt, conductive carbon, graphite, plain-carbon steel, stainless steel, ferritic stainless steel, copper, and bronze.
In some embodiments, the heating material may be heated by induction heating. Induction heating is a process in which an electrically-conductive object is heated by penetrating the object with a varying magnetic field. In some embodiments, the heating material may be heated by resistive heating. In such embodiments, the heating material is connected to a power supply. Alternatively, the heating may be microwave heating or infrared heating.
In some embodiments, the heating material is a strip or ribbon embedded in the support. In some embodiments, the heating material a rough surface, or holes, for example in the form of a mesh or a perforated sheet. In some embodiments, the heating material is in particulate form.
In some embodiments, the heating material is in the form of a coating applied to one or more other components of the support.
A key consideration in this invention is balancing the trapping of the aerosol-generating material within the support material, whilst still providing the aerosol-generating material in a form that can volatilise during heating to generate the desired aerosol and/or vapour. This requires space for the aerosol-generating material, and so the support needs to be sufficiently porous to provide this space. This porosity is also required to ensure that the aerosol and/or vapour generated by heating the aerosol-generating material can be released from the substrate. It is therefore important for the substrate to have pores and channels to permit the aerosol and/or vapour generation and release. The support materials and the support or substrate configurations described herein all provide these,
In the embodiments in which the support is a sheet material, the surface roughness of the sheet will contribute to the required porosity of the substrate.
Surface roughness is a component of surface texture and it is generally quantified by the deviations in the direction of the normal vector of a real surface from its ideal form. The profile roughness parameters are included in BS EN ISO 4287:2000 British standard, which is identical to the ISO 4287:1997 standard. One test of surface smoothness (or roughness) is the Bekk smoothness which is measured by an air leak method in which a test surface is clamped between a flat glass plate and a circular metal head and air is drawn across the surface of the test piece under a partial vacuum. The rate of airflow is measured in ml/minute between the paper and the applicable standards are ISO 5627, Tappi T479 and DIN 53107.
In some embodiments, high “loft” materials may be particularly suitable for ensuring good aerosolisation. Folding, creping or embossing of the various sheet materials disclosed herein may provide these materials with additional loft to benefit aerosol generation and release from the substrates formed using such support materials.
The aerosol-generating material comprises a dried extract from a flavour- and/or active-containing plant material. In some embodiments, the aerosol-generating material further comprises an aerosol-former material.
In some embodiments, the aerosol-generating material is formed by drying a precursor material comprising an extract from a flavour- and/or active-containing plant material. The drying process is selected to retain the desired components of the precursor material and, therefore, the aerosol-generating material may comprise one or more active substances and/or flavours.
In some embodiments, the precursor material further comprises one or more aerosol-former material. Additionally or alternatively, one or more aerosol-former materials may be added to the dried precursor material to provide an aerosol-generating material with the desired aerosol-former material content.
In some embodiments, the extract from a flavour- or active-substance containing plant material is an extract derived by contacting the plant material with a suitable solvent, such as an aqueous solvent or an alcohol such as ethanol. The liquid portion comprising the solvent and any dissolved plant components may then be separated or partially separated from the remaining solid plant material to provide the extract to be included in the precursor composition and dried.
Therefore, the aerosol-generating material may comprise one or more active substances and/or flavours, and optionally one or more aerosol-former materials. The precursor material and/or the dried aerosol-generating material may also optionally include one or more other functional materials.
The invention enjoys the advantage of an aerosol-generating material that is formulated to have an increased shelf life and so it may be easily transported and stored. Without wishing to be bound by any particular theory, it is hypothesised that the low water content of the dried aerosol-generating material reduces evaporation over time of other solvents, and reduces degradation of nicotine and/or other volatile compounds. A low water content also inhibits microbial growth.
The compositions comprising the dried aerosol-generating materials described herein are stable at a range of temperatures and humidities and have an increased shelf-life, and are therefore easy to store and transport. In some embodiments, the compositions may be stored at temperatures in the range of 0-35° C. In some embodiments, the compositions may be stored at a relative humidity of up to about 30%, or even as high as 50%, prior to use.
The aerosol-generating materials also have the advantage of having a high concentration of the desired components. This means that relatively small amounts of the aerosol-generating material are required and less energy is required to heat and release the desired components. Significantly, the aerosols generated from these materials also provide an authentic tobacco taste of reasonable strength.
A further advantage of the aerosol-generating materials is that they may be used as a solid aerosol-generating substrate in Hybrid systems or Tobacco Heating Products (THPs). This makes the invention versatile enough to be used in a range of products without the need for further processing.
In some embodiments, the extract from a flavour- or active-substance containing plant material is an extract derived from tobacco material.
The tobacco extract or material may be from or may be any type of tobacco and any part of the tobacco plant, including tobacco lamina, stem, stalk, ribs, scraps and shorts or mixtures of two or more thereof. Suitable tobacco extracts or materials include the following types: Virginia or flue-cured tobacco, Burley tobacco, Oriental tobacco, or blends of tobacco materials, optionally including those listed here. The tobacco may be expanded, such as dry-ice expanded tobacco (DIET), or processed by any other means. In some embodiments, the tobacco material may be reconstituted tobacco material. The tobacco may be pre-processed or unprocessed, and may be, for instance, solid stems (SS); shredded dried stems (SDS); steam treated stems (STS); or any combination thereof. The tobacco material may be fermented, cured, uncured, toasted, or otherwise pre-treated. The tobacco material may be provided in the form of cut rag tobacco. The cut rag tobacco can have a cut width of at least 15 cuts per inch (about 5.9 cuts per cm, equivalent to a cut width of about 1.7 mm) for example. The cut rag tobacco can be formed from a mixture of forms of tobacco material, for instance a mixture of one or more of paper reconstituted tobacco, leaf tobacco, extruded tobacco and bandcast tobacco.
The precursor material which is dried to form the aerosol-generating material may comprise 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 % tobacco solids (calculated on a wet weight basis). Additionally or alternatively, the precursor material may comprise up to about 60 wt %, up to about 55 wt %, up to about 50 wt %, up to about 45 wt %, or up to about 40 wt % tobacco solids (calculated on a wet weight basis). In some embodiments, the precursor material comprises from about 20 wt % to about 40 wt % tobacco solids (calculated on a wet weight basis).
In some embodiments, the precursor material comprises at least about 10 wt %, about 20 wt %, at least about 30 wt %, at least about 40 wt %, at least about 50 wt %, at least about 60 wt %, at least about 70 wt %, at least about 80 wt %, or at least about 90 wt % extract from a tobacco or other flavour- or active-substance containing plant material (calculated on a wet weight basis). Alternatively or additionally, precursor material may comprise up to about 99 wt %, up to about 90 wt %, up to about 80 wt %, up to about 70 wt % or up to about 60 wt % extract from tobacco or other flavour- or active-substance containing plant material (calculated on a wet weight basis). In some embodiments, the precursor material comprises around 50 wt % tobacco extract (calculated on a wet weight basis).
In some embodiments, the aerosol-generating material may comprise at least about 45 wt %, at least about 50 wt %, at least about 60 wt %, at least about 70 wt %, at least about 80 wt %, at least about 90 wt %, or at least about 95 wt % tobacco material or tobacco extract, or flavour- or active-substance containing plant material extract (calculated on a dry weight basis). In some embodiments, the aerosol-generating material may comprise about 60 to about 80 wt % tobacco extract (calculated on a dry weight basis).
In some embodiments, the dried aerosol-generating material may comprise from about 2 wt % to about 10 wt % nicotine, or from about 3 to about 6 wt % of nicotine (calculated on a dry weight basis).
In some embodiments, the precursor material comprises around 50 v/v % tobacco extract. Where the precursor material comprises around 50 v/v % tobacco extract and the tobacco extract has a tobacco solid content of between about 55 and about 60 v/v %, the overall tobacco solid content of the precursor material is from about 27.5 to about 30 v/v %.
In some embodiments, the tobacco extract has a solids content of between about 40 and about 65 wt %, between about 45 and about 65 wt %, or between about 40 and about 60 wt % (calculated on a wet weight basis). In some embodiments, the water content of the tobacco extract is between about 35 wt % and about 65 wt %, or between about 35 and about 55 wt % (calculated on a wet weight basis). In some embodiments, the nicotine content of the tobacco extract is between about 1 wt % and about 5 wt % (calculated on a wet weight basis).
In some embodiments, the dried aerosol-generating material may comprise at least about 45 wt %, at least about 50 wt %, at least about 60 wt %, at least about 70 wt %, at least about 80 wt %, at least about 90 wt %, or at least about 95 wt % tobacco solids (calculated on a dry weight basis). Additionally or alternatively, the aerosol-generating material may comprise up to about 99 wt %, up to about 98 wt %, up to about 95 wt %, up to about 90 wt % or up to about 80 wt %. In some embodiments, the dried aerosol-generating material may comprise about 60 to about 80 wt % tobacco solids (calculated on a dry weight basis).
In some embodiments, the tobacco extract is an aqueous tobacco extract. In some embodiments, the tobacco extract may be concentrated and subsequently diluted before being added to the precursor material and dried. In other embodiments, the tobacco extract is not concentrated and may be used directly in the precursor material.
The precursor material may be in the form of a slurry, a suspension, a gel, a liquid or a solid, but in some embodiments which may be preferred, it is in the form of a suspension or liquid. In some embodiments, particles of solid material may be removed from the extract and/or from the precursor material by filtration and/or centrifugation.
In some embodiments, it may be desirable for any particles in the precursor composition to have an average particle size of no greater than about 3 mm, of no greater than 1 mm, of no greater than about 0.5 mm, or to have an average particle size of no greater than about 0.3 mm, when measured by sieving or by observing the size of the particles by SEM.
The water content of the precursor material may be at least about 20 wt %, at least about 30 wt %, at least about 40 wt %, at least about 50 wt %, at least about 60 wt %, at least about 70 wt %, at least about 80 wt %, or at least about 90 wt % on a wet weight basis. Alternatively or additionally, the water content of the precursor material may be up to about 95 wt %, up to about 90 wt %, up to about 85 wt %, up to about 80 wt %, up to about 75 wt %, up to about 70 wt %, up to about 65 wt %, up to about 60 wt %, up to about 55 wt % or up to about 50 wt % on a wet weight basis. In some embodiments, the water content of the precursor material is between about 40 and about 50 wt % on a wet weight basis (50% and 60 v/v %). When the precursor material has a lower water content, the spray/freeze-drying process is quicker, as there is less water to remove.
In some embodiments, the dried aerosol-generating material and/or the precursor material comprises one or more active substance. This may be derived from the extract or it may be added. In some embodiments, the extract from a flavour- or active-substance containing plant material comprises an active substance.
The active substance may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics and psychoactives. The active substance may comprise, for example, nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.
In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.
In some embodiments, the precursor material may comprise an extract from other botanical source(s) along with or instead of the tobacco extract.
As noted herein, the extract may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term “botanical” includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. The extract may comprise or be derived from botanicals in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like. Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, Ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v., Mentha spicata crispa, Mentha cardifolia, Mentha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens
In some embodiments, the extract comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof selected from eucalyptus, star anise, cocoa and hemp.
In some embodiments, the extract comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof selected from rooibos and fennel.
In some embodiments, the aerosol-generating material and/or the precursor material comprises one or more cannabinoid compounds selected from the group consisting of: cannabidiol (CBD), tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabichromene (CBC), cannabicyclol (CBL), cannabivarin (CBV), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabigerol monomethyl ether (CBGM) and cannabielsoin (CBE), cannabicitran (CBT).
The aerosol-generating material and/or the precursor material may comprise one or more cannabinoid compounds selected from the group consisting of cannabidiol (CBD) and THC (tetrahydrocannabinol).
The aerosol-generating material and/or the precursor material may comprise cannabidiol (CBD).
The aerosol-generating material and/or the precursor material may comprise nicotine and cannabidiol (CBD).
The aerosol-generating material and/or the precursor material may comprise nicotine, cannabidiol (CBD), and THC (tetrahydrocannabinol).
The aerosol-generating material further comprises an aerosol-former material. In some embodiments, this aerosol-former material is included in the precursor material.
The aerosol-former material may comprise one or more constituents capable of forming an aerosol. The aerosol-former may be, for instance, a polyol aerosol generator or a non-polyol 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.
In some embodiments, the aerosol former 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. Glycerol provides a visible aerosol when the aerosol-generation device is used. It is common that consumers like the aerosol generating device to provide a visible aerosol, as this enables the consumer to visualise the product and what they are consuming. This makes glycerol a desirable choice for aerosol former material. Propylene glycol has the benefit that it is a better flavour carrier than glycerol.
A combination of two or more aerosol forming agents may be used, in equal or differing proportions.
In some embodiments, the precursor material comprises at least about 1 wt %, at least about 5 wt %, at least about 10 wt %, or at least about 20 wt %, aerosol-former material (calculated on a wet weight basis). Additionally or alternatively, the precursor material may comprise up to about 40 wt %, up to about 35, up to about 30 wt %, up to about 25 wt %, up to about 20 wt %, or up to about 10 wt % aerosol-former material (calculated on a wet weight basis).
In embodiments of the invention in which the aerosol-former material is glycerol, the precursor material may comprise at most 36 wt % of glycerol. The inventors have demonstrated that dry weight inclusion levels up to 36 wt % (calculated on a dry weight basis) of aerosol-former material are possible.
The amount of glycerol in the precursor material, and therefore the dried aerosol material, is important because it is both an aerosol-forming material and also a plasticizer. If the concentration of glycerol it too high, it may be detrimental to a critical temperature of the product during the freeze-drying process and may result in collapse of the product if the critical temperature of the formulation is exceeded. On the other hand, sufficient glycerol should be included to provide the consumer with an adequate and pleasing aerosol.
As glycerol and some other aerosol-former materials are considered to have anti-freeze properties, it is particularly surprising that it is possible to freeze-dry a precursor material comprising such materials. Nevertheless, the inventors have discovered that precursor materials comprising glycerol may be freeze dried to form a highly useful aerosol-generating material.
In some embodiments, the dried aerosol-generating material may comprise at least about 1 wt %, at least about 5 wt %, at least about 10 wt %, at least about 20 wt %, at least about 30 wt %, or at least about 40 wt % aerosol-former material (calculated on a dry weight basis).
In some embodiments, the dried aerosol-generating material may comprise from about 1 to about 34 wt %, or from about 17 to about 34 wt % aerosol-former material (calculated on a dry weight basis). In some embodiments in which the aerosol-former material is glycerol, the dried aerosol-generating material may comprise from about 13 to about 34 wt % glycerol (calculated on a dry weight basis).
In embodiments in which Burley tobacco is used, the aerosol-generating material may comprise from about 17 to about 36 wt % of glycerol. The amount of glycerol in the aerosol material is important because it is both an aerosol-forming material and a plasticizer. If the concentration of glycerol is too high, it may be detrimental to the critical temperature of the product during the freeze-drying process and may result in collapse of the product if a critical temperature of the formulation is exceeded. On the other hand, sufficient glycerol should be included to provide the consumer with an adequate and pleasing aerosol.
In some embodiments, the aerosol-generating material and/or the precursor material further comprises one or more excipients. In some embodiments, the excipient stabilises and preserves the precursor material and the inventors have found the inclusion of an excipient especially important for stability when the precursor material comprised glycerol as the aerosol-forming material. The excipient may also act as a bulking agent or a filler material. In some embodiments, the inclusion of an excipient may also improve the handleability of the dried aerosol-generating material, helping it to retain its granular form by helping to reduce moisture uptake and the resulting increase in tackiness of the material. The presence of an excipient may also have an effect on the speed of (freeze) drying.
Suitable excipients include mannitol, sucrose, trehalose, lactose, sorbitol, raffinose, maltose, dextrans such as Dextran 10, Dextran 70, Dextran 90, maltodextrin, gelatin, agar, cyclodextrins, and polyethylene glycols such as PEG 2000-6000, and polyvinylpyrrolidone (PVP 10).
In some embodiments, the aerosol-generating material and/or the precursor material comprises one or more excipients in an amount of from 0 to about 40 wt % on a wet weight basis. In some embodiments, the precursor material may comprise at least about 1 wt %, at least about 10 wt %, at least about 20 wt %, at least about 30 wt %, and/or up to about 40 wt %, up to about 30%, up to about 20 wt %, or up to about 10 wt % excipient on a wet weight basis.
In some embodiments, the aerosol-generating material may comprise at least about 0.1 wt %, at least about 10 wt %, at least about 20 wt %, or at least about 25 wt % excipient (calculated on a dry weight basis). In some embodiments, the aerosol-generating material may comprise up to about 25%, up to about 20 wt %, up to about 15 wt %, or up to about 10 wt % excipient (calculated on a dry weight basis).
In an exemplary embodiment, the aerosol-generating material comprises about 36 wt % glycerol, about 45 wt % tobacco extract, and about 19 wt % excipient on a dry weight basis.
In another exemplary embodiment, the aerosol-generating material comprises from about 17 to about 39 wt % glycerol, from about 41 to about 76 wt % tobacco extract, and from 0 to about 28 wt % excipient on a dry weight basis.
In embodiments in which the excipient is agar, the precursor material may comprise about 0 wt %, about 5 wt %, or about 10 wt % agar. The inventors have found that agar makes the precursor material more viscous and that the freeze-drying process is easier when the precursor material comprises a lower concentration of the agar excipient.
In some embodiments, the precursor material comprises about 50 wt % tobacco extract, from 0 to about 36 wt % aerosol forming agent (for example, from 0 to about 15 v/v %) and from 0 to about 40 wt % (for example, about 37.5 v/v %) excipient. The tobacco extract may comprise about 55 wt % tobacco solids and the overall tobacco solids content of the precursor material is about 27.5 wt %.
Some sample formulations of dried aerosol-generating materials formed from aqueous tobacco extracts are summarised in Table 1 below, with the amounts provided on a dry weight basis. These are theoretical values (before drying and inherent losses). Typically from about 80 to 89% of the glycerol is retained following the drying. Glycerol may be used as an aerosol-former material, but can be replaced or partially replaced with one or more other aerosol-former material such as those disclosed herein. The excipient used may be a dextran such as Dextran 70. Again, this may be replaced or partially replaced with alternative excipients, such as those disclosed herein.
The percentage content of nicotine in the formulation will depend on the type of tobacco used, and the presence of other components, i.e. the aerosol-former and the excipient.
In some embodiments, the aerosol-generating material comprises one or more binders. In some embodiments the one or more binder is selected from the group consisting of: thermoreversible gelling agents, such as gelatin; starches; polysaccharides; pectins; celluloses; cellulose derivatives, such as carboxymethylcellulose; and alginates.
In some embodiments, the amount of binder used to adhere the aerosol-generating material to the support is from about 1 to about 30% by weight based on the weight of the aerosol-generating material. In some embodiments, the amount of binder used is up to about 20%, up to about 15%, up to about 10% by weight of the aerosol-generating material. Additionally or alternatively, the amount of binder when used may be at least about 1%, at least about 2%, at least about 5% or at least about 8% by weight of the aerosol-generating material
In some embodiments, the aerosol-generating material and/or the precursor material comprises one or more flavour-modifier, flavour or flavourant. This may be derived from the extract or it may be added. 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, or gas.
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.
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 eucolyptol, WS-3.
In some embodiments, the aerosol-generating material and/or the precursor material comprises one or more other functional materials, which may comprise one or more of pH regulators, colouring agents, preservatives, fillers, stabilizers, and/or antioxidants.
In some embodiments, the aerosol-generating material and/or the precursor material contains a filler component. The filler component is generally a non-tobacco component, that is, a component that does not include ingredients originating from tobacco. In some embodiments, the precursor material comprises less than 60 wt % of a filler, such as from 1 wt % to 60 wt %, or 5 wt % to 50 wt %, or 5 wt % to 30 wt %, or 10 wt % to 20 wt % on a wet weight basis.
The filler, if present, may comprise one or more inorganic filler materials such as calcium carbonate, perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesium sulphate, magnesium carbonate, and suitable inorganic sorbents, such as molecular sieves. The filler may comprise one or more organic filler materials such as wood pulp, hemp fibre, cellulose and cellulose derivatives.
In some embodiments, the dried aerosol-generating material is in the form of a gel. A gelling agent may be added to the aerosol-generating material, the precursor material or may be optionally omitted. The gelling agent may comprise one or more compounds selected from cellulosic gelling agents, non-cellulosic gelling agents, guar gum, acacia gum and mixtures thereof.
In some embodiments, the cellulosic gelling agent is selected from the group consisting of: hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylcellulose (CMC), hydroxypropyl methylcellulose (HPMC), methyl cellulose, ethyl cellulose, cellulose acetate (CA), cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP) and combinations thereof.
In some embodiments, the gelling agent comprises (or is) one or more of hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose (HPMC), carboxymethylcellulose, guar gum, or acacia gum.
In some embodiments, the gelling agent comprises (or is) one or more non-cellulosic gelling agents, including, but not limited to, agar, xanthan gum, gum Arabic, guar gum, locust bean gum, pectin, carrageenan, starch, alginate, and combinations thereof. In preferred embodiments, the non-cellulose based gelling agent is alginate or agar.
The aerosol-generating material and/or the precursor material may comprise an acid. The acid may be an organic acid. In some of these embodiments, the acid may be at least one of a monoprotic acid, a diprotic acid and a triprotic acid. In some such embodiments, the acid may contain at least one carboxyl functional group. In some such embodiments, the acid may be at least one of an alpha-hydroxy acid, carboxylic acid, dicarboxylic acid, tricarboxylic acid and keto acid. In some such embodiments, the acid may be an alpha-keto acid.
In some such embodiments, the acid may be at least one of succinic acid, lactic acid, benzoic acid, citric acid, tartaric acid, fumaric acid, levulinic acid, acetic acid, malic acid, formic acid, sorbic acid, benzoic acid, propanoic and pyruvic acid. In some embodiments, the acid is selected from one of lactic acid, benzoic acid and levulinic acid.
In other embodiments the acid may be an inorganic acid. In some of these embodiments the acid may be a mineral acid. In some such embodiments, the acid may be at least one of sulphuric acid, hydrochloric acid, boric acid and phosphoric acid.
The inclusion of an acid may be beneficial in embodiments in which the aerosol-generating material and/or the precursor material comprises nicotine. In such embodiments, the presence of an acid may stabilise dissolved species in the slurry from which the aerosol-generating material is formed. The presence of the acid may reduce or substantially prevent evaporation of nicotine during drying of the slurry, thereby reducing loss of nicotine during manufacturing.
In certain embodiments, the aerosol-generating material comprises a gelling agent comprising a cellulosic gelling agent and/or a non-cellulosic gelling agent, an active substance and an acid.
The dried aerosol-generating material may be in any solid form. For example, the aerosol-generating material may be in the form of particles, granules or powder. The aerosol-generating material may be in the form of a monolithic form, tablet, agglomerate or “cake”. In some embodiments, the aerosol-generating material formed by freeze- or spray-drying and is then processed with other suitable steps as required and known to the person skilled in the art to provide the dried material in the desired form, for example in the form of particles of the desired size(s).
In some embodiments, the aerosol-generating material is in the form of particles or granules. The granules may be of any size, cross-sectional shape or mass. The aerosol-generating material in the form of granules is advantageous due to the high surface area to volume ratio, which positively impacts the release of volatiles from the material. This form also facilitates incorporation of the material into an aerosol provision system.
Smaller granule particles have a greater surface area to volume ratio and they may therefore exhibit enhanced release of tobacco constituents compared to particles of larger sizes. They will also have a greater tendency to adhere to surfaces, such as the rough surface of the support.
In some embodiments, it may be desirable for the particles in the precursor composition, to have an average particle size of no greater than about 3 mm, no greater than 1 mm, no greater than 500 μm, no greater than about 200 μm, no greater than 100 μm, no greater than about 50 μm, no greater than 40 μm, no greater than about 30 μm, no greater than 20 μm, no greater than about 10 μm, no greater than about 5 μm or to have an average particle size of no greater than about 1 μm, when measured by sieving.
In some embodiments, the average particle size is within the range of from about 0.1 μm to about 1 mm, from about 0.1 μm to about 500 μm, from about 10 μm to about 200 μm, from about 10 μm to about 100 μm, or in the range of from about 10 μm to about 50 μm. In some embodiments, at least about 90% of the particles of the precursor composition will have a particle size within the range of from about 1 μm to about 1 mm, or from about 10 to about 500 μm, or from about 50 to about 200 μm. In some embodiments, at least about 90% of the tobacco particles of the precursor composition will have a particle size within the range of from about 1 μm to about 1 mm, or from about 10 to about 500 μm, or from about 50 to about 200 μm. In some embodiments, none of the particles in the precursor composition have a particle size greater than 1 mm, greater than 0.5 mm, greater than 0.2 mm, greater than 0.15 mm, or greater than about 0.1 mm. In some embodiments, the average particle size is less than 50 μm.
When preparing the precursor compositions to be dried, the particle size of any solid material present may be reduced by grinding, shredding, cutting or crushing tobacco material. Suitable machinery to create such plant particles includes, for example, shredders, cutters, or mills, such as hammer mills, roller mills or other types of commercially available milling machinery. The size of the plant particles is selected to provide particles which can be readily prepared from a variety of different types of plant material, having the properties described herein, and which provide a source of plant constituents that are readily released.
Particles of the aerosol-generating material of a smaller size may be advantageous for aerosol generation. Without wishing to be bound by any particular theory, smaller particles may have a greater surface area to volume ratio, which may improve aerosol generation. In some embodiments, the dried aerosol-generating material readily forms particles with an average size of smaller than 1 mm. In some embodiments, the particles may be as small as 10 μm or even as small as 1 μm. The size of the particles may be determined by sieving or by observing the particles by SEM.
In the context of the present invention, smaller particles of the solid aerosol-generating material may be preferred. Particle adhesion between particles and a surface, or between particles involves a variety of different forces, including van der Waals forces, diffusion, mechanical interaction and electrostatic attraction. At least some of these forces are generally stronger the greater the surface energy of the particles and this is related to the size of the particles. Essentially, smaller particles tend to be more “sticky”. Therefore, in some embodiments, the particles of the aerosol-generating material have a particle size of no greater than 50 μm, no greater than 40 μm, no greater than 30 μm, no greater than 20 μm or no greater than to μm. Such small particle sizes also mean that the rough surface of the support does not need to have large pores or irregularities to accommodate particles of such dimensions.
In some embodiments, the freeze dried precursor material is ground into particles and may be sieved to exclude particles that are considered too small or too large to be used as aerosol-generating material.
In some embodiments, aerosol-generating material used in the present invention has a particle size distribution D10 from about 5 to about 25 μm (meaning that 10% of the particles in the tested sample are smaller than the value), a particle size distribution D50 from about 30 to about 200 μm (meaning that 50% of the particles in the tested sample are smaller than the value), and a particle size distribution D90 from about 500 to about 2500 μm (meaning that 90% of the particles in the tested sample are smaller than the value). These values are determined using particle size analyser Microtrac CamSizer® X2. Percentages referred to here are volume percentages.
In some embodiments, the freeze dried material used as the aerosol-generating material according to the present invention has a particle size distribution D10 from about 8 to about 15 μm, a particle size distribution D50 from about 50 to about 150 μm, and a particle size distribution D90 from about 900 to about 1700 μm.
In some embodiments, the D10 mean is from about 10 to about 15 μm, the D50 mean from about 40 to about 140 μm and the D90 mean from about 800 to about 1600 μm.
The drying methods used to dry the precursor material may be any suitable drying process, including freeze-drying or spray-drying processes. The drying process used must be compatible with the precursor material and the desired make-up of the aerosol-generating material. As it may be desirable for the aerosol-generating material to include active and/or flavour substances derived from the extract in the precursor material, it is important to select a drying method that will retain a sufficient amount of these components.
In small scale examples, the precursor material is freeze-dried using freeze-drying microscopy, for example using a Lyostat freeze-drying microscope.
In a spray-drying process, the precursor material is sprayed and rapidly dried using a hot gas. The use of spray drying provides several advantages to the present invention: the dry particle size can be controlled and may be consistent; tobacco or flavour extracts or materials are heat sensitive but can still be spray-dried at relatively high inlet temperatures; a short residence time in the spray-drying equipment is required; and minimal loss of flavour/volatiles. This makes the process adaptable to reduce loss of volatile compounds and maintain the desired flavour of the aerosol generating material.
Freeze-drying, also known as lyophilisation or cryodesiccation, is a process in which the precursor material is frozen, the temperature lowered and the water is removed via sublimation under reduced pressure conditions. Without wishing to be bound by any specific theory, it is believed that the low processing temperatures and rapid water loss via sublimation avoid changes in the aerosol-generating material's structure, appearance and characteristics. This process preserves the structure of the precursor material, and reduces the loss and decomposition of volatile flavour compounds.
The dried aerosol-generating material has a lower water content than the precursor material. The water content of the aerosol-generating material may be at most about 0.5 wt %, about 1 wt %, about 2%, about 5 wt %, about 10 wt %, or about 20 wt % (calculated on a wet weight basis). The water content of the dried aerosol-generating material may be reduced from the precursor material by at least about 50 wt %, about 60 wt %, about 70 wt %, about 80 wt %, about 90 wt %, about 95 wt %, about 98 wt %, or by about 100 wt %. In some embodiments the dried aerosol-generating material has a water content of less than about 5 wt %, less than about 4 wt %, less than about 3 wt %, less than about 2 wt % or less than about 1 wt % (calculated on a wet weight basis), as measured by gas chromatography-thermal conductivity detector (GC-TCD) or Karl Fischer measurement.
In an exemplary embodiment of the invention, the precursor material comprises Burley tobacco extract and a water content of 60 wt %. After the freeze-drying operation described herein, the dried aerosol generating material has a water content of 3 wt %.
A lower water content of the dried aerosol-generating material is associated with longer shelf-life and stability. However, very low water content may be associated be a brittle structure and a smaller particle size, as well as taking longer to process. The material is also very hygroscopic. If the water content of the dried aerosol-generating material is too high on the other hand, the desired increased stability may not be achieved. The dried aerosol-generating material may also not be as easy to handle with higher water content, with the material becoming sticky.
The inventors have found that when the precursor material comprises an excipient, the precursor material may be better suited to being dried via spray-drying (compared to a precursor material without an excipient). Without wishing to be bound by any particular theory, it is speculated that increasing the amount of the excipient in the precursor material raises the glass transition temperature to above 100° C. and this affects the physical properties of the material, making it more suitable for spray drying.
The substrates comprising the aerosol-generating material and support may be used in combustible or non-combustible aerosol provision systems, or in an aerosol-free delivery system.
The present invention also relates to a consumable or article, comprising an aerosol-generating material surrounded by a support.
In some embodiments, the substrate is provided in a consumable. Alternatively, the substrate may be used as a consumable.
A consumable is an article comprising aerosol-generating material, part or all of which is intended to be consumed during use by a user. In this case, the aerosol-generating material, or at least some of the aerosol-generating material, is provided as part of a substrate as disclosed herein, comprising the aerosol-generating material and a support.
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. As mentioned above, at least some of these components of a consumable may also be components of the substrate described herein.
The consumable may be any shape or size that is appropriate to the aerosol-generating device. In some embodiments, the consumable is a rod shape. In other embodiments, it may take the form of a flat strip, a tube, a disc, or a flexible sleeve.
In some embodiments, the substrate comprising an aerosol-generating material and a support is provided in an aerosol-generating device such as a tobacco-heating product (THP) or hybrid e-cigarette product. Advantageously, the substrate may be directly heated without burning to provide an inhalable aerosol. In some embodiments, heating the substrate will first cause the coating to decompose, to breach the barrier it forms around the aerosol-generating material. Then, the aerosolised components of the aerosol-generating material, for example the glycerol, nicotine and/or tobacco flavour will be released.
In some embodiments, the substrate comprising an aerosol-generating material and a support may be incorporated into the consumable in the absence of any other carrier or other material that would need to be heated.
In other embodiments, the substrate comprises multiple layers, for example in the form of a laminate. For example, the substrate may comprise alternating layers of support material and aerosol-generating material. In some embodiments, further layers of different material may be included, such as layers of a further, different aerosol-generating material, or a layer comprising an aerosol-modifying agent, such as a flavour.
In some embodiments, the consumable comprises a moisture impermeable coating that surrounds but which may be separate from the aerosol-generating material. For example, the moisture impermeable coating may surround the substrate (thereby surrounding the aerosol-generating material within the composition). In some embodiments, the moisture impermeable coating may be provided as a film or wrapper, optionally being deposited on a moisture permeable carrier.
In some embodiments, the consumable comprises a sorbent or desiccant material. The sorbent or desiccant material may be provided in the substrate as discussed above.
Alternatively, these components may be provided separately in the consumable, but in such a manner that the sorbent still competes with the aerosol-generating material for the moisture in the environment and therefore reduces the amount of moisture absorbed by the aerosol-generating material. In some embodiments, the sorbent may be provided in or on a wrapper that surrounds the aerosol generating material in the consumable. In other embodiments, the sorbent may be incorporated into a separate section of the consumable to the aerosol-generating material. This may have the benefit of reducing the exposure of the sorbent to the high temperatures that the aerosol-generating material is heated to upon use. For example, the sorbent may be located in an adjacent section of the consumable which is not directly heated. This may be downstream or upstream of the aerosol-generating material. In some embodiments, the sorbent is included in one or more sections of the consumable that does not include the aerosol-generating material, such as a cooling element section, or a filter section.
In yet further embodiments, the sorbent may be separated or removed from the aerosol-generating material and/or from the consumable before it is used. For example, the sorbent may be located in the packaging within which the consumable is held prior to use. In some embodiments, this packaging may be a wrapper, a box or other container. The sorbent may be incorporated into the packaging material or part thereof. Alternatively, the sorbent may be provided in a separate article, such as a sachet or sheet, located with the consumable within the packaging.
The delivery systems described herein can be combustible aerosol provision systems, non-combustible aerosol provision systems or an aerosol-free delivery systems.
As used herein, the term “delivery system” is intended to encompass systems that deliver at least one substance to a user, and includes:
According to the present disclosure, a “combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is combusted or burned during use in order to facilitate delivery of at least one substance to a user.
In some embodiments, the delivery system is a combustible aerosol provision system, such as a system selected from the group consisting of a cigarette, a cigarillo and a cigar.
In some embodiments, the disclosure relates to a component for use in a combustible aerosol provision system, such as a filter, a filter rod, a filter segment, a tobacco rod, a spill, an aerosol-modifying agent release component such as a capsule, a thread, or a bead, or a paper such as a plug wrap, a tipping paper or a cigarette paper.
According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating 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.
In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.
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 aerosol-generating material is not a requirement.
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.
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 and may be an aerosol-generating material provided on a support. 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 a solid aerosol-generating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.
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.
In some embodiments, the disclosure relates to consumables comprising a substrate comprising an aerosol-generating material and a support and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.
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 a substrate comprising an aerosol-generating material and a support or to a heat transfer material in proximity to the exothermic power source.
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.
In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise a substrate comprising an aerosol-generating material and a support, 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.
The aerosol generating segment 12 is in the form of a cylindrical rod and comprises a substrate 14. In one embodiment, this substrate comprises an extruded rod formed by extruding a mixture of support material, such as tobacco particles, with particles of aerosol-generating material. In other embodiments, the substrate 14 is a substrate as illustrated in either of
Although described above in rod form, the aerosol-generating segment 12 can be provided in other forms.
The mouthpiece segment 11 in the illustrated embodiment includes a body of material 15 such as a plug of fibrous or filamentary tow. Between the aerosol generating segment 12 and the mouthpiece segment 11, there is positioned a cooling section 13 comprising a hollow tube 16 formed from a suitable material such as cellulose acetate, paper or a heat absorbing material.
The consumable 10 further comprises a wrapper 17, such as a paper wrapper, circumscribing the mouthpiece segment 11, the cooling section 13 and the aerosol generating segment 12.
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
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.
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.
In some embodiments, the substance to be delivered may be the aerosol-generating material of a substrate as described herein, and optionally another aerosol-generating material that may or may not be heated. As appropriate, the substrate and other aerosol-generating material may comprise one or more active constituents, one or more flavours, one or more aerosol-former materials, and/or one or more other functional materials.
The invention enjoys the advantage of longer shelf life than other tobacco extracts.
The nicotine content of the precursor and aerosol-generating material after the freeze drying process has been calculated, providing an indication of the amount of nicotine retained following the processing. Compared to the original tobacco extract, the nicotine recovery of the dried aerosol generating material is at least about 76 wt % on a dry weight basis. The nicotine recovery of the dried aerosol generating material compared to the original tobacco extract may be at least about 60%, at least about 70%, at least about 75%, at least about 80%, or at least about 00% on a dry weight basis.
The glycerol content of the precursor and dried aerosol-generating material after the freeze drying process has been calculated, providing an indication of the amount of glycerol retained following the processing. Compared to the precursor material, the glycerol recovery of the dried aerosol generating material is at least about 85%. The glycerol recovery of the dried aerosol generating material compared to the precursor material may be at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90% at least about 95% on a dry weight basis.
In addition, once surrounded by the moisture impermeable coating, the content of volatile components such as nicotine and flavours, and the content of the aerosol-forming material in the aerosol-generating material will be maintained until the composition is heated to generate an aerosol. This will be even without packaging or other protection from exposure to moisture.
In a first test, the precursor material comprised essentially of aqueous tobacco extract, and glycerol. The aqueous tobacco extract was diluted further with glycerol up to about 24 wt % (calculated on a dry weight basis). The Burley aqueous tobacco extract had a tobacco solid content of about 40 wt %, and a water content of about 60 wt %. The precursor material was dried via freeze drying.
In a further test, the precursor material comprised essentially of aqueous tobacco extract, glycerol and Dextran 70. The glycerol content was about 0 to about 15 v/v %, or up to about 36 wt % calculated on a dry weight basis. The precursor material was dried via freeze drying.
The freeze-dried aerosol-generating material of Example 1 or Example 2 is ground to provide a loose powder with an average size of from about 10 μm to about 50 μm. 50 mg of the powder is then applied to the surface of a support comprising a sheet of paper having a porous surface texture. The particles of the aerosol-generating material readily nestle within the pores of the paper to form a substrate. The support sheet is rolled to form a rod which is incorporated into a consumable. The rolled sheet holds the particles of aerosol-generating material between layers of the support material, so that the aerosol-generating material is surrounded by the support.
A significant proportion of the particles will remain in place even when the substrate is packaged and transported.
The freeze-dried aerosol-generating material of Example 1 or Example 2 is ground to provide a loose powder with an average size of from about 500 μm to about 1000 μm. As a fibrous cellulose acetate tow is gathered and formed into a cylindrical plug, the powdered aerosol generating material is added so that it is embedded in and distributed throughout the support material to form a substrate.
The freeze-dried aerosol-generating material of Example 1 or Example 2 is ground to provide a loose powder with an average size of from about 10 μm to about 50 μm. 200 mg of the powder is then added during the manufacture of a sheet of air-laid paper so that the particles of aerosol-generating material are embedded within the structure of the air-laid sheet. The air-laid paper sheet is then overlaid with an aluminium foil sheet that will act as a susceptor. The two sheet payers are then rolled to form a rod comprising the support material, aerosol-generating material and heating material. The particles of the aerosol-generating material are surrounded by the first support (the air-laid paper) and the second support (the sheet of heating material), which protect it and hold in in place.
The freeze-dried aerosol-generating material of Example 1 or Example 2, particles of tobacco material, and particles of a metal heating material are co-extruded to form a solid mass that is cut to a desired size and used in a consumable as an aerosol-generating substrate.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2204839.1 | Apr 2022 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2023/050863 | 3/31/2023 | WO |
