Modified aerosol-generating elements for use in aerosol-generating articles or systems

Abstract

An aerosol-generating element for use in an aerosol-generating article or system is provided. The aerosol-generating element includes a solid continuous matrix structure and an aerosol-generating formulation dispersed within the solid continuous matrix structure. The aerosol-generating formulation is entrapped within the solid continuous matrix structure and is releasable from the solid continuous matrix structure upon heating of the aerosol-generating element. The solid continuous matrix structure is a polymer matrix including one or more matrix-forming polymers. The aerosol-generating formulation dispersed within the solid continuous matrix structure includes at least one alkaloid or cannabinoid compound and a polyhydric alcohol. Furthermore, the aerosol-generating formulation dispersed within the solid continuous matrix structure accounts for at least 80 weight percent of the total weight of the aerosol-generating element.

Description

[Technical field]

[0001] The present invention relates to an aerosol-generating element that finds particular application in an aerosol-generating article or system. The present invention further relates to an aerosol-generating article or system that includes such an aerosol-generating element. [Background technology]

[0002] Aerosol-generating articles in which an aerosol-generating substrate, such as a tobacco-containing substrate, is heated rather than combusted are known in the art. Typically, in such articles, an aerosol is generated by transferring heat from a heat source to a physically separate aerosol-generating substrate or material, which may be located in contact with, within, around, or downstream of the heat source. During use of the aerosol-generating article, volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol.

[0003] Numerous prior art documents disclose aerosol generating devices for consuming aerosol-generating articles, including, for example, electrically heated aerosol generating devices in which the aerosol is generated by heat transfer from one or more electric heater elements of the aerosol generating device to an aerosol-generating substrate of a heated aerosol-generating article.

[0004] Substrates for heated aerosol generating articles have often been produced using randomly oriented pieces, strands, or strips of tobacco material. Alternatively, rods for heated aerosol generating articles formed from an assembly of sheets of tobacco material are disclosed, by way of example, in WO2012 / 164009.

[0005] WO2011 / 101164 discloses an alternative rod for a heated aerosol generating article formed from a strand of homogenized tobacco material, which may be formed by casting, rolling, calendaring or extrusion of a mixture comprising particulate tobacco and at least one aerosol former to form a sheet of homogenized tobacco material. In an alternative embodiment, the rod of WO2011 / 101164 may be formed from a strand of homogenized tobacco material obtained by extruding a mixture comprising particulate tobacco and at least one aerosol former to form a continuous length of homogenized tobacco material.

[0006] Substrates for heated aerosol-generating articles typically further comprise an aerosol former, i.e., a compound or mixture of compounds that facilitates the formation of an aerosol during use and that is preferably substantially resistant to thermal decomposition at the use temperature of the aerosol-generating article. Examples of suitable aerosol formers include, but are not limited to, polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0007] Alternative forms of nicotine-containing substrates have also been disclosed. As an example, liquid nicotine compositions, often referred to as e-liquids, have been proposed. These liquid compositions can be heated, for example, by a coiled, electrically resistive filament in an aerosol generating device.

[0008] Substrates of this type may require special care in the manufacture of the container that holds the liquid composition to prevent unwanted leakage.

[0009] It has been proposed before to provide encapsulated nicotine formulations for use as aerosol generating substrates. However, encapsulation of nicotine formulations has proven difficult. One reason for this is that hydrophilic aerosol formers such as glycerin and propylene glycol in nicotine formulations are preferred, which makes it difficult to use many commonly used encapsulation materials that are also hydrophilic. It is generally found that existing encapsulation techniques require such high levels of hydrophilic encapsulation materials to produce stable products that provide insufficient payloads of nicotine formulations.

[0010] While hydrophobic encapsulation materials are available, such materials often need to be processed at relatively high temperatures, which poses the risk of decomposition of the nicotine formulation during manufacture. During use, the temperature required to generate an aerosol from a nicotine formulation may be high enough to cause decomposition of the hydrophobic encapsulation material. This may result in the release of undesirable compounds into the resulting aerosol, which may adversely affect the sensory profile of the aerosol.

[0011] It has also been proposed to provide a gel composition comprising nicotine adapted to generate a nicotine-containing aerosol upon heating. As an example, WO2018 / 019543 discloses a thermoreversible gel composition, i.e., a gel that becomes fluid when heated to a melting temperature and solidifies again into a gel at a gelling temperature. WO2018 / 019543 discloses providing such a gel in a cartridge housing. The cartridge may be disposed of and replaced when the gel is consumed. In order for the gel composition to generate a satisfactory amount of aerosol during use, it is desirable for the gel composition to include a significant amount of an aerosol former, such as glycerol. However, due to the plasticizing properties of glycerol, it may be difficult to provide a gel composition that can provide good aerosol delivery during use and at the same time is geometrically stable, i.e., does not undergo significant volume loss as the gel composition solidifies and settles into a film form.

[0012] It is therefore desirable to provide alternative, novel encapsulated aerosol-generating formulations, e.g., aerosol-generating elements that encapsulate nicotine-containing formulations, which provide improved encapsulating substrates with enhanced stability and minimal leakage of the aerosol-generating formulation.

[0013] It is also desirable to provide such aerosol-generating elements that are easy to handle, such as to facilitate the manufacture and packaging of aerosol-generating articles that include one or more of the aerosol-generating elements.It is also desirable to provide such encapsulated aerosol-generating formulations that have minimal encapsulation structure to provide efficient aerosol delivery, especially when heated to temperatures in the range of about 150 degrees Celsius to about 350 degrees Celsius. Summary of the Invention

[0014] The present disclosure relates to an aerosol-generating element for use in an aerosol-generating article or system. The aerosol-generating element may include a solid continuous matrix structure and an aerosol-generating formulation dispersed within the solid continuous matrix structure. The aerosol-generating formulation may be entrapped within the solid continuous matrix structure and releasable from the solid continuous matrix structure upon heating of the aerosol-generating element. The solid continuous matrix structure may be a polymer matrix including one or more matrix-forming polymers. The aerosol-generating formulation dispersed within the solid continuous matrix structure may include at least one alkaloid or cannabinoid compound. The aerosol-generating formulation dispersed within the solid continuous matrix structure may include a polyhydric alcohol. The aerosol-generating formulation dispersed within the solid continuous matrix structure may account for at least about 80 weight percent of the total weight of the aerosol-generating element.

[0015] The present disclosure further relates to an aerosol generating article comprising one or more aerosol generating elements as described above.The present disclosure further relates to an aerosol generating system comprising one or more aerosol generating elements or articles as described above, and an electrically operated aerosol generating device comprising a heating element and a heating chamber configured to receive the aerosol generating element or article such that the aerosol generating element is heated in the heating chamber by the heating element.

[0016] According to the present invention there is provided an aerosol-generating element for use in an aerosol-generating article or system comprising a solid continuous matrix structure and an aerosol-generating formulation dispersed within the solid continuous matrix structure, wherein the aerosol-generating formulation is entrapped within the solid continuous matrix structure and releasable from the solid continuous matrix structure upon heating of the aerosol-generating element, wherein the solid continuous matrix structure is a polymeric matrix comprising one or more matrix-forming polymers, wherein the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least one alkaloid or cannabinoid compound, and a polyhydric alcohol, and wherein the aerosol-generating formulation dispersed within the solid continuous matrix structure accounts for at least about 80 weight percent of the total weight of the aerosol-generating element.

[0017] The term "aerosol-generating article" is used herein with respect to the present invention to describe an article in which an aerosol-generating substrate is heated to generate an aerosol for delivery to a consumer. As used herein, the term "aerosol-generating substrate" refers to a substrate that has the ability to release volatile compounds upon heating to generate an aerosol.

[0018] The term "aerosol-generating element" is used herein with reference to the present invention to describe a separate, free-standing aerosol-generating substrate element capable of releasing a volatile compound when heated to generate an aerosol. An aerosol-generating element according to the present invention may find use as an aerosol-generating substrate in an aerosol-generating article.

[0019] The aerosol generated from the aerosol-generating formulation of the aerosol-generating element described herein is a dispersion of solid particles or liquid droplets (or a combination of solid particles and liquid droplets) in a gas. The aerosol may be visible or invisible and may include vapors of substances that are normally liquid or solid at room temperature, as well as solid particles or liquid droplets or a combination of solid particles and liquid droplets.

[0020] A conventional cigarette is lit when a user applies an ignition source to one end of the cigarette and draws air through the other end. Localized heat provided by the flame and oxygen in the air drawn through the cigarette ignites the end of the cigarette, and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol-generating articles, the aerosol is generated by heating a flavor-generating substrate, such as, for example, a tobacco-derived substrate or a substrate containing an aerosol former and a flavoring agent. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which the aerosol is generated by heat transfer from a combustible fuel element or heat source to a physically separated aerosol-forming material.

[0021] For example, the aerosol-generating article according to the present invention may find particular application in an aerosol-generating system comprising an electrically heated aerosol-generating device having an internal heater adapted to supply heat to one or more individual aerosol-generating substrate elements. As used herein with respect to the present invention, the term "aerosol-generating device" is used to describe a device comprising a heater element that interacts with one or more aerosol-generating elements according to the present invention to generate an aerosol. During use, volatile compounds are released from the aerosol-generating element(s) by heat transfer and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol, which is inhaled by the consumer.

[0022] Substrates for heated aerosol-generating articles typically comprise an "aerosol former", i.e., a compound or mixture of compounds that facilitates the formation of an aerosol during use and that is preferably substantially resistant to thermal decomposition at the use temperature of the aerosol-generating article. Examples of suitable aerosol formers include polyhydric alcohols (such as propylene glycol, triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate or triacetate), and aliphatic esters of mono-, di- or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.). The polyhydric alcohols in the aerosol-generating articles of the present invention are also aerosol formers within the meaning given above.

[0023] As used herein in connection with the present invention, the term "aerosol-generating formulation" refers to a formulation that includes multiple aerosol-generating formulation components, which upon heating of an aerosol-generating element becomes volatile to generate an aerosol.

[0024] As used herein in connection with the present invention, the term "matrix-forming polymer" refers to an encapsulating material in the form of a polymer that can generate a three-dimensional polymer matrix as a result of crosslinking when the matrix-forming polymer is contacted with a crosslinking solution of a multivalent cation. The resulting polymer matrix is ​​capable of entrapping and retaining the aerosol-generating formulation within its crosslinked structure. The properties of the crosslinked polymer matrix are discussed in more detail below.

[0025] As briefly mentioned above, in contrast to existing aerosol-generating elements, the aerosol-generating element according to the present invention comprises a solid continuous matrix structure and an aerosol-generating formulation dispersed within the solid continuous matrix structure. More specifically, the aerosol-generating formulation is entrapped within the solid continuous matrix structure and can be released from the solid continuous matrix structure upon heating the aerosol-generating element to a predetermined temperature.

[0026] Without intending to be bound by theory, it is understood that in the aerosol-generating elements according to the present invention, a three-dimensional polymer matrix structure is formed by crosslinking and the aerosol-generating formulation is held within the polymer matrix structure, particularly in contrast to existing core / shell structures, where the contents of the core are released upon rupture of the shell.

[0027] In the aerosol-generating element according to the invention, the solid continuous matrix structure is a polymeric matrix comprising one or more matrix-forming polymers, and further, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 80 weight percent of the total weight of the aerosol-generating element.

[0028] Advantageously, the present invention provides an encapsulated form of an aerosol-generating formulation with a significantly lower content of encapsulating material (corresponding to one or more matrix-forming polymers of a solid continuous matrix structure) compared to previously available substrates.In this way, the level of aerosol-generating formulation components, such as alkaloids or cannabinoids and polyhydric alcohols, can be advantageously maximized within the aerosol-generating element.Furthermore, the reduction in the proportion of encapsulating material required allows for more efficient generation of aerosols upon heating, since less heat provided to the aerosol-generating element is used to increase the temperature of the encapsulating material.

[0029] The polymer-derived solid continuous matrix of the aerosol-generating article according to the invention provides an inert encapsulation structure for holding and immobilizing the aerosol-generating formulation, which is stable upon heating of the aerosol-generating element during use. The inventors have discovered that upon heating to temperatures between 150 degrees Celsius and 350 degrees Celsius, the aerosol-generating element according to the invention releases the aerosol while undergoing significant weight loss. However, this weight loss is not accompanied by an equally significant volume loss. Without intending to be bound by theory, upon heating, the components of the aerosol-generating formulation originally dispersed and trapped within the solid continuous matrix structure are substantially evaporated and released. Meanwhile, the components of the solid continuous matrix are substantially unaffected, and the solid continuous matrix only partially shrinks while essentially retaining its 3D structure. Thus, the encapsulation of the aerosol-generating formulation within the polymer-derived matrix advantageously results in minimal or no adverse effects on the sensory profile of the aerosol generated upon heating.

[0030] The aerosol generating elements of the present invention have been found to advantageously provide controlled delivery of an aerosol. Moreover, the aerosol delivery profile can be easily adjusted by adjusting the parameters of the aerosol generating elements, such as the size, shape, structure, and formulation of the aerosol generating elements.

[0031] The present invention advantageously provides aerosol-generating elements in the form of individual, free-standing solid objects that are sufficiently stable and robust to be easily handled and incorporated into aerosol-generating articles using existing methods and techniques.

[0032] Furthermore, the aerosol-generating elements according to the invention may be prepared by a cost-effective method that can be carried out on existing equipment, as will become apparent from the following description. Furthermore, the aerosol-generating elements according to the invention may be prepared by a method that can be easily integrated into existing manufacturing lines for the manufacture of aerosol-generating articles.

[0033] The aerosol-generating element according to the present invention can be prepared from a matrix precursor solution and the components of an aerosol-generating formulation. As an example, in a method for producing an aerosol-generating element according to the present invention, a matrix precursor solution can be provided that includes a matrix-forming polymer in water. It is preferred that the matrix polymer solution includes at least about 35 weight percent water, more preferably at least about 40 weight percent water. This level of water ensures that the matrix-forming polymer is sufficiently dissolved to provide a homogeneous solution.

[0034] The matrix-forming polymer may be a single polymer or a combination of two or more polymers, where one or more polymers can form a crosslinked matrix via an ionotropic gelation mechanism in a crosslinking solution of a multivalent cation. Crosslinking of the matrix-forming polymer is achieved by reacting the polymer with a multivalent cation in the crosslinking solution, which forms salt bridges to crosslink the polymer molecules. Suitable matrix-forming polymers are known to those skilled in the art and include, but are not limited to, alginate, pectin, hydroxyethyl methacrylate (HEMA), N-(2-hydroxypropyl) methacrylate (HPMA), N-vinyl-2-pyrrolidone (NVP), N-isopropylacrylamide (NIPAMM), vinyl acetate (VAc), acrylic acid (AA), methacrylic acid (MAA), polyethylene glycol acrylate / methacrylate (PEGA / PEGMA), and polyethylene glycol diacrylate / dimethacrylate, (PEGDA / PEGDMA).

[0035] The matrix-forming polymer preferably comprises one or more polysaccharides, such as alginate or pectin, or a combination thereof. Polysaccharides are particularly suitable for use in the present invention, since they can be cross-linked to make them insoluble in water, heat stable, and tasteless. Thus, they do not adversely affect the sensory properties of the aerosol generated from the aerosol generating element. Alternative matrix-forming polymers suitable for use in the method according to the present invention include, but are not limited to, chitosan, fibrin, collagen, gelatin, hyaluronic acid, dextran, and combinations thereof.

[0036] In a preferred embodiment, the matrix-forming polymer is a single polysaccharide. It is even more preferred that the matrix-forming polymer is an alginate. In other words, in this particularly preferred embodiment, the solid continuous matrix structure is an alginate polymer matrix. In the first step, a plurality of aerosol-generating formulation components may be added to a matrix precursor solution to form an aerosol-generating solution, where the aerosol-generating formulation components include at least one alkaloid or cannabinoid compound and a polyhydric alcohol. When used herein in describing the method of preparing an aerosol-generating element according to the present invention, the term "aerosol-generating solution" refers to a solution of aerosol-generating formulation components and matrix precursor in a suitable solvent.

[0037] Suitable polyhydric alcohols for use in the aerosol generating elements include, but are not limited to, propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin. In the aerosol generating elements produced according to the present invention, the polyhydric alcohol is preferably selected from the group consisting of glycerin, propylene glycol, and combinations thereof. In a particularly preferred embodiment, the polyhydric alcohol is glycerin. The alkaloid is preferably selected from the group consisting of nicotine, anatabine, and combinations thereof.

[0038] It may be desirable to control the viscosity of the aerosol-generating solution. This may include controlling the viscosity of the matrix polymer solution when the aerosol-generating formulation components are added. For example, depending on the technique used to generate the individual portions of the aerosol-generating solution in successive steps of the method, it may be preferable to provide the aerosol-generating solution with a viscosity within a certain range. Different techniques are likely to be facilitated by different viscosity solutions, so the appropriate viscosity should be determined depending on the technique used. As an example, if the individual portions of the aerosol-generating solution are generated by a gravity drop process, the viscosity of the solution is preferably kept below about 5000 mPa.s. (milli-Pascal seconds). This allows the droplets of the aerosol-generating solution to form under gravity and also allows the beads to reach a stable shape in the crosslinking solution before the crosslinking hardens the solution and fixes the final shape of the aerosol-generating element.

[0039] In certain cases, it may be preferable to control the pH of the matrix polymer solution while the aerosol-generating formulation components are being added in order to control the viscosity of the aerosol-generating solution. This is because pH can affect the viscosity of some matrix polymer solutions. For example, in embodiments of the present invention in which the matrix-forming polymer comprises alginate, it is preferable to keep the pH of the solution above pH 4. This is intended to avoid gelling of alginate, which may occur at a pH below pH 4, for example due to hydrogen bonding. Such gelling at low pH causes an undesirable increase in the viscosity of the aerosol-generating solution, which makes it difficult to use certain techniques, such as gravity dripping, to form the aerosol-generating element.

[0040] Alternatively, or additionally, the viscosity of the aerosol-generating solution may be controlled by adjusting the concentration of the solution. For example, the percentage of water in the aerosol-generating solution may be adjusted to adjust the viscosity. The aerosol-generating solution preferably contains at least about 35 percent water by weight to maintain a suitable viscosity. It is particularly preferred that the aerosol-generating solution contains about 35 percent to about 65 percent water by weight. In a second step, separate portions of the aerosol-generating solution may be formed. In a third step, the formed separate portions of the aerosol-generating solution may be added to a cross-linking solution of a multivalent cation to cross-link the matrix-forming polymer, thereby forming an aerosol-generating element having a continuous polymer matrix structure, and an aerosol-generating formulation including the aerosol-generating component dispersed within the continuous polymer matrix. Preferred multivalent cations include calcium, iron, aluminum, manganese, copper, zinc or lanthanum. A particularly preferred salt is calcium chloride.

[0041] In certain preferred embodiments of the invention in which the aerosol-generating solution comprises an acid, the calcium salt provided in the cross-linking solution may advantageously be a salt of the same acid, for example in embodiments in which the aerosol-generating solution comprises lactic acid, the cross-linking solution may advantageously comprise calcium lactate.

[0042] When the aerosol-generating solution contains nicotine, the acid in the aerosol-generating solution forms a nicotine salt with the nicotine. Thus, the use of a calcium salt corresponding to the acid in the aerosol-generating solution provides the cross-linking solution with the same salt as that in the aerosol-generating solution. This in turn advantageously limits the diffusion of the nicotine salt from the aerosol-generating solution to the cross-linking solution during the cross-linking step. Thus, a higher concentration of the nicotine salt can be retained within the aerosol-generating element. Furthermore, any potential waste of nicotine and acid during the production of the aerosol-generating element can be reduced.

[0043] The cross-linking solution preferably further comprises a polyhydric alcohol identical to the polyhydric alcohol selected as an aerosol-generating formulation component. It has been found that the inclusion of the polyhydric alcohol in the cross-linking solution limits the diffusion of the polyhydric alcohol from the aerosol-generating solution to the cross-linking solution during the cross-linking step. This advantageously allows a higher concentration of the polyhydric alcohol to be maintained within the aerosol-generating element than previously possible.

[0044] In a fourth step, the aerosol-generating component may be removed from the crosslinking solution and dried.As briefly discussed above, in the aerosol-generating components according to the present invention, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 80 weight percent of the total weight of the aerosol-generating component.

[0045] More preferably, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 82 weight percent of the total weight of the aerosol-generating component. Even more preferably, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 84 weight percent of the total weight of the aerosol-generating component.

[0046] In particularly preferred embodiments, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 86 weight percent of the total weight of the aerosol-generating element. More preferably, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 88 weight percent of the total weight of the aerosol-generating element. Even more preferably, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 90 weight percent of the total weight of the aerosol-generating element.

[0047] Most preferably, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least about 92 percent by weight of the total weight of the aerosol-generating components, or at least about 93 percent by weight of the total weight of the aerosol-generating components, or at least about 94 percent by weight of the total weight of the aerosol-generating components, or at least about 95 percent by weight of the total weight of the aerosol-generating components.

[0048] When the aerosol-generating formulation in an aerosol-generating element occupies a percentage of the total weight of the aerosol-generating element within the above-mentioned ranges, it is advantageously possible to minimize the portion of the heat supplied to the aerosol-generating element during use that is consumed to raise the temperature of the encapsulating material, thus allowing more efficient use of the heat supplied to the aerosol-generating element, so that a large portion of that heat is effectively used to release the aerosol-forming components from the solid continuous matrix structure and generate an aerosol.

[0049] As mentioned above, in the aerosol-generating elements according to the invention, the solid continuous matrix structure is a polymer matrix comprising one or more matrix-forming polymers. Suitable matrix-forming polymers will be known to those skilled in the art.

[0050] Preferably, the one or more matrix-forming polymers comprise one or more polysaccharides. More preferably, the one or more matrix-forming polymers comprise at least one of alginate and pectin. Polysaccharides are particularly suitable for use in the present invention because they can be cross-linked to make them insoluble in water and heat stable, and are also tasteless. Therefore, they do not adversely affect the sensory properties of the aerosol generated from the aerosol generating element.

[0051] In a preferred embodiment, the matrix-forming polymer is a single polysaccharide. Even more preferably, the matrix-forming polymer is an alginate. In other words, in this particularly preferred embodiment, the solid continuous matrix structure is an alginate polymer matrix.

[0052] It is preferred to use alginate as the only matrix-forming polymer because alginate has the ability to promote the rapid formation of insoluble solid aerosol-generating elements. More specifically, the inventors have found that the use of alginate as the only matrix-forming polymer, particularly in the amounts described below, advantageously provides aerosol-generating elements that are stable and self-supporting and capable of retaining high concentrations of polyhydric alcohol within the polymer matrix. Furthermore, compared to other formulations, the use of alginate as the only matrix-forming polymer, particularly in the amounts described below, has been found to allow the formation of larger aerosol-generating elements, for example in the form of spherical or quasi-spherical beads with larger diameters.

[0053] In an aerosol-generating element according to the invention, the solid continuous matrix structure is an alginate polymer matrix, and preferably the aerosol-generating element comprises at least about 1 weight percent alginate, more preferably the aerosol-generating element comprises at least about 1.5 weight percent alginate, and even more preferably the aerosol-generating element comprises at least about 2 weight percent alginate.

[0054] In a particularly preferred embodiment, the aerosol-generating component comprises at least about 3 weight percent alginate.

[0055] In the aerosol-generating element according to the invention, the solid continuous matrix structure is an alginate polymer matrix, and preferably the aerosol-generating element comprises no more than about 10 weight percent alginate, more preferably the aerosol-generating element comprises no more than about 8 weight percent alginate, and even more preferably the aerosol-generating element comprises no more than about 6 weight percent alginate.

[0056] In a particularly preferred embodiment, the aerosol-generating component comprises up to about 5 weight percent alginate.

[0057] In some embodiments, the solid continuous matrix structure is an alginate polymer matrix and the aerosol-generating component comprises from about 1 weight percent to about 10 weight percent alginate. The aerosol-generating component preferably comprises from about 1.5 weight percent to about 10 weight percent alginate, more preferably from about 2 weight percent to about 10 weight percent alginate, and even more preferably from about 3 weight percent to about 10 weight percent alginate.

[0058] In another embodiment, the solid continuous matrix structure is an alginate polymer matrix and the aerosol-generating component comprises from about 1 weight percent to about 8 weight percent alginate. The aerosol-generating component preferably comprises from about 1.5 weight percent to about 8 weight percent alginate, more preferably from about 2 weight percent to about 18 weight percent alginate, and even more preferably from about 3 weight percent to about 8 weight percent alginate.

[0059] In a further embodiment, the solid continuous matrix structure is an alginate polymer matrix and the aerosol-generating component comprises from about 1 weight percent to about 6 weight percent alginate. The aerosol-generating component preferably comprises from about 1.5 weight percent to about 6 weight percent alginate, more preferably from about 2 weight percent to about 6 weight percent alginate, and even more preferably from about 3 weight percent to about 6 weight percent alginate.

[0060] Alternative matrix-forming polymers suitable for use in the aerosol-generating elements according to the present invention include, but are not limited to, chitosan, fibrin, collagen, gelatin, hyaluronic acid, dextran, and combinations thereof.

[0061] Further alternative matrix-forming polymers suitable for use in the aerosol-generating elements according to the present invention may be constructed from one or more of the following monomers and polymers: hydroxyethyl methacrylate (HEMA), N-(2-hydroxypropyl) methacrylate (HPMA), N-vinyl-2-pyrrolidone (NVP), N-isopropylacrylamide (NIPAMM), vinyl acetate (VAc), acrylic acid (AA), methacrylic acid (MAA), polyethylene glycol acrylate / methacrylate (PEGA / PEGMA), and polyethylene glycol diacrylate / dimethacrylate, (PEGDA / PEGDMA).

[0062] As defined above, the aerosol-generating element according to the present invention comprises a polyhydric alcohol as a component of the aerosol-generating formulation dispersed within a solid continuous matrix structure.

[0063] The polyhydric alcohol acts as an aerosol-forming agent in the aerosol-generating element. Suitable polyhydric alcohols for use in the aerosol-generating element include, but are not limited to, propylene glycol, triethylene glycol, 1,3-butanediol, and glycerin. In the aerosol-generating element according to the present invention, the polyhydric alcohol is preferably selected from the group consisting of glycerin, propylene glycol, and combinations thereof. In a particularly preferred embodiment, the polyhydric alcohol is glycerin.

[0064] The polyhydric alcohol content in the aerosol-generating formulation is preferably at least 30 percent by weight based on the total weight of the aerosol-generating components. Thus, one such aerosol-generating component contains at least about 30 percent by weight of polyhydric alcohol.

[0065] In some embodiments, the polyhydric alcohol content in the aerosol-generating formulation is preferably at least about 35 weight percent based on the total weight of the aerosol-generating components. Thus, the aerosol-generating components according to the present invention contain at least about 35 weight percent polyhydric alcohol. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is at least 40 weight percent based on the total weight of the aerosol-generating components.

[0066] In particularly preferred embodiments, the polyhydric alcohol content in the aerosol-generating formulation is at least about 45 weight percent based on the total weight of the aerosol-generating components. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is at least about 50 weight percent based on the total weight of the aerosol-generating components. Even more preferably, the polyhydric alcohol content in the aerosol-generating formulation is at least about 55 weight percent based on the total weight of the aerosol-generating components. Most preferably, the polyhydric alcohol content in the aerosol-generating formulation is at least about 60 weight percent, or at least about 65 weight percent, or at least about 70 weight percent based on the total weight of the aerosol-generating components.

[0067] Typically, in aerosol-generating elements according to the present invention, the polyhydric alcohol content in the aerosol-generating formulation comprises no more than about 95 weight percent, based on the total weight of the aerosol-generating element.

[0068] In the aerosol-generating element according to the present invention, the polyhydric alcohol content in the aerosol-generating formulation is preferably about 90 weight percent or less based on the total weight of the aerosol-generating element. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 85 weight percent or less based on the total weight of the aerosol-generating element. Even more preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 80 weight percent or less based on the total weight of the aerosol-generating element.

[0069] In a preferred embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 30 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements. The polyhydric alcohol content in the aerosol-generating formulation is preferably about 35 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 40 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements. Even more preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 45 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements. In a particularly preferred embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 50 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements, more preferably about 55 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements, and even more preferably about 60 weight percent to about 95 weight percent based on the total weight of the aerosol-generating elements. Most preferably, the polyhydric alcohol content in the aerosol-generating formulation is from about 65 weight percent to about 95 weight percent, based on the total weight of the aerosol-generating components, or even from about 70 weight percent to about 95 weight percent, based on the total weight of the aerosol-generating components.

[0070] In these embodiments, the aerosol-generating element may comprise from about 30 percent to about 95 percent by weight of polyhydric alcohol. More preferably, the aerosol-generating element comprises from about 35 percent to about 95 percent by weight of polyhydric alcohol. Even more preferably, the aerosol-generating element comprises from about 40 percent to about 95 percent by weight of polyhydric alcohol. Most preferably, the aerosol-generating element comprises from about 45 percent to about 95 percent by weight of polyhydric alcohol. In particularly preferred embodiments, the aerosol-generating element comprises from about 50 percent to about 95 percent by weight of polyhydric alcohol, preferably from about 55 percent to about 95 percent by weight of polyhydric alcohol, more preferably from about 60 percent to about 95 percent by weight of polyhydric alcohol, even more preferably from about 65 percent to about 95 percent by weight of polyhydric alcohol, and most preferably from about 70 percent to about 95 percent by weight of polyhydric alcohol.

[0071] In other embodiments, the polyhydric alcohol content in the aerosol-generating formulation is about 30 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements. The polyhydric alcohol content in the aerosol-generating formulation is preferably about 35 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 40 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements. Even more preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 45 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements. In a particularly preferred embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 50 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements, more preferably about 55 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements, and even more preferably about 60 weight percent to about 90 weight percent based on the total weight of the aerosol-generating elements. In the most preferred embodiments, the polyhydric alcohol content in the aerosol-generating formulation comprises from about 65 weight percent to about 90 weight percent, or even from about 70 weight percent to about 90 weight percent, based on the total weight of the aerosol-generating components.

[0072] In these embodiments, the aerosol-generating element according to the present invention may comprise from about 30 weight percent to about 90 weight percent polyhydric alcohol. Preferably, the aerosol-generating element comprises from about 35 weight percent to about 90 weight percent polyhydric alcohol. More preferably, the aerosol-generating element comprises from about 40 weight percent to about 90 weight percent polyhydric alcohol. Even more preferably, the aerosol-generating element comprises from about 45 weight percent to about 90 weight percent polyhydric alcohol. In particularly preferred embodiments, the aerosol-generating element comprises from about 50 weight percent to about 90 weight percent polyhydric alcohol, preferably from about 55 weight percent to about 90 weight percent polyhydric alcohol, more preferably from about 60 weight percent to about 90 weight percent polyhydric alcohol, even more preferably from about 65 weight percent to about 90 weight percent polyhydric alcohol, and most preferably from about 70 weight percent to about 90 weight percent polyhydric alcohol.

[0073] In a further embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 30 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements. The polyhydric alcohol content in the aerosol-generating formulation is preferably about 35 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 40 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements. Even more preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 45 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements. In a particularly preferred embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 50 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements, more preferably about 55 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements, and even more preferably about 60 weight percent to about 85 weight percent based on the total weight of the aerosol-generating elements. In the most preferred embodiments, the polyhydric alcohol content in the aerosol-generating formulation comprises from about 65 weight percent to about 85 weight percent, or even from about 70 weight percent to about 85 weight percent, based on the total weight of the aerosol-generating components.

[0074] In these embodiments, the aerosol-generating element according to the present invention may comprise from about 30 weight percent to about 85 weight percent polyhydric alcohol. Preferably, the aerosol-generating element comprises from about 35 weight percent to about 85 weight percent polyhydric alcohol. More preferably, the aerosol-generating element comprises from about 40 weight percent to about 85 weight percent polyhydric alcohol. Even more preferably, the aerosol-generating element comprises from about 45 weight percent to about 85 weight percent polyhydric alcohol. In particularly preferred embodiments, the aerosol-generating element comprises from about 50 weight percent to about 85 weight percent polyhydric alcohol, preferably from about 55 weight percent to about 85 weight percent polyhydric alcohol, more preferably from about 60 weight percent to about 85 weight percent polyhydric alcohol, even more preferably from about 65 weight percent to about 85 weight percent polyhydric alcohol, and most preferably from about 70 weight percent to about 85 weight percent polyhydric alcohol.

[0075] In yet a further embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 30 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements. The polyhydric alcohol content in the aerosol-generating formulation is preferably about 35 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements. More preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 40 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements. Even more preferably, the polyhydric alcohol content in the aerosol-generating formulation is about 45 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements. In a particularly preferred embodiment, the polyhydric alcohol content in the aerosol-generating formulation is about 50 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements, more preferably about 55 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements, and even more preferably about 60 weight percent to about 80 weight percent based on the total weight of the aerosol-generating elements. In the most preferred embodiments, the polyhydric alcohol content in the aerosol-generating formulation comprises from about 65 weight percent to about 80 weight percent, or even from about 70 weight percent to about 80 weight percent, based on the total weight of the aerosol-generating components.

[0076] In such embodiments, the aerosol-generating element according to the present invention may comprise from about 30 weight percent to about 80 weight percent of polyhydric alcohol. Preferably, the aerosol-generating element comprises from about 35 weight percent to about 80 weight percent of polyhydric alcohol. More preferably, the aerosol-generating element comprises from about 40 weight percent to about 80 weight percent of polyhydric alcohol. Even more preferably, the aerosol-generating element comprises from about 45 weight percent to about 80 weight percent of polyhydric alcohol. In particularly preferred embodiments, the polyhydric alcohol content in the aerosol-generating formulation is from about 50 weight percent to about 80 weight percent, preferably from about 55 weight percent to about 80 weight percent, more preferably from about 60 weight percent to about 80 weight percent, even more preferably from about 65 weight percent to about 80 weight percent, and most preferably from about 70 weight percent to about 80 weight percent, based on the total weight of the aerosol-generating element.

[0077] As briefly described above, in an aerosol-generating element according to the invention, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least one alkaloid or cannabinoid compound, hi some embodiments, the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises both an alkaloid compound and a cannabinoid compound.

[0078] As used herein in connection with the present invention, the term "alkaloid compound" is used to describe any one of a class of naturally occurring organic compounds that contain one or more basic nitrogen atoms. Generally, alkaloids contain at least one nitrogen atom in an amine-type structure. This nitrogen atom or another nitrogen atom in the molecule of the alkaloid compound can be active as a base in an acid-base reaction. Most alkaloid compounds have one or more of their nitrogen atoms as part of a ring system, such as a heterocycle. In nature, alkaloid compounds are found primarily in plants and are particularly common in certain families of flowering plants. However, some alkaloid compounds are found in animal species and fungi. In the context of the present invention, the term "alkaloid compound" is used to describe both naturally occurring and synthetically produced alkaloid compounds. Suitable alkaloid compounds for use in the aerosol generating elements according to the present invention include, but are not limited to, nicotine and anatabine.

[0079] As used herein with respect to the present invention, the term "cannabinoid compound" is used to describe any one of a class of naturally occurring compounds found in parts of the cannabis plant, namely Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the female flower heads. Naturally occurring cannabinoid compounds in the cannabis plant include tetrahydrocannabinol (THC) and cannabidiol (CBD). In the context of the present invention, the term "cannabinoid compound" is used to describe both naturally occurring and synthetically produced cannabinoid compounds.

[0080] Cannabinoid compounds suitable for use in the aerosol-generating films according to the present invention include tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (CBT).

[0081] In general, the aerosol-generating element may contain up to about 10 weight percent of alkaloid compounds or cannabinoid compounds, or both. Considering the application of the aerosol-generating element of the present invention as a substrate in an aerosol-generating article, this is advantageous because the content of alkaloid compounds or cannabinoid compounds, or both, in the element can be increased and adjusted to optimize the delivery of alkaloid compounds or cannabinoid compounds, or both, in aerosol form to consumers. Compared to existing aerosol-generating substrates based on the use of plant materials, this may advantageously allow a higher content of alkaloid compounds or cannabinoid compounds, or both, per volume of substrate (element(s)) or per weight of substrate (element(s)), which may be desirable from a manufacturing point of view.

[0082] The content of the at least one alkaloid or cannabinoid compound in the aerosol-generating formulation dispersed within the solid continuous matrix structure preferably accounts for at least 0.5 weight percent of the total weight of the aerosol-generating element.Thus, the aerosol-generating element preferably contains at least about 0.5 weight percent of an alkaloid compound, or at least 0.5 weight percent of a cannabinoid compound, or at least about 0.5 weight percent of a combination of an alkaloid compound and a cannabinoid compound.

[0083] More preferably, the aerosol-generating component contains at least about 1 weight percent of the alkaloid compound or the cannabinoid compound, or both. Even more preferably, the aerosol-generating component contains at least about 2 weight percent of the alkaloid compound or the cannabinoid compound, or both.

[0084] Preferably, the aerosol-generating element contains less than about 8 weight percent alkaloid and / or cannabinoid compounds. More preferably, the aerosol-generating element contains less than about 6 weight percent alkaloid and / or cannabinoid compounds. Even more preferably, the aerosol-generating film contains less than about 5 weight percent alkaloid and / or cannabinoid compounds. Most preferably, the aerosol-generating film contains less than about 4 weight percent alkaloid and / or cannabinoid compounds.

[0085] In some embodiments, the aerosol-generating element contains from about 0.5 percent to about 10 percent by weight of an alkaloid compound or cannabinoid compound, or both, more preferably from about 1 percent to about 10 percent by weight of an alkaloid compound or cannabinoid compound, or both, and even more preferably from about 2 percent to about 10 percent by weight of an alkaloid compound or cannabinoid compound, or both.

[0086] In other embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 8 weight percent of the alkaloid or cannabinoid compound, or both, more preferably from about 1 weight percent to about 8 weight percent of the alkaloid or cannabinoid compound, or both, and even more preferably from about 2 weight percent to about 8 weight percent of the alkaloid or cannabinoid compound, or both.

[0087] In further embodiments, the aerosol-generating element contains from about 0.5 percent to about 6 percent by weight of alkaloid or cannabinoid compounds, or both, more preferably from about 1 percent to about 6 percent by weight of alkaloid or cannabinoid compounds, or both, and even more preferably from about 2 percent to about 6 percent by weight of alkaloid or cannabinoid compounds, or both.

[0088] In still further embodiments, the aerosol-generating element contains from about 0.5 percent to about 5 percent by weight of alkaloid or cannabinoid compounds, or both, more preferably from about 1 percent to about 5 percent by weight of alkaloid or cannabinoid compounds, or both, and even more preferably from about 2 percent to about 5 percent by weight of alkaloid or cannabinoid compounds, or both.

[0089] In particularly preferred embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 4 weight percent of an alkaloid compound or cannabinoid compound, or both, more preferably from about 1 weight percent to about 4 weight percent of an alkaloid compound or cannabinoid compound, or both, and even more preferably from about 2 weight percent to about 4 weight percent of an alkaloid compound or cannabinoid compound, or both.

[0090] In some embodiments, the aerosol-generating element comprises one or more of a cannabinoid and an alkaloid compound, including nicotine or anatabine. In some preferred embodiments, the aerosol-generating element comprises nicotine.

[0091] As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salt. In embodiments in which the aerosol-generating element comprises nicotine base or nicotine salt, the amount of nicotine recited herein is the amount of free base nicotine or the amount of protonated nicotine, respectively.

[0092] The aerosol-generating element may contain natural or synthetic nicotine.

[0093] The aerosol-generating element may include one or more monobasic nicotine salts.

[0094] As used herein with respect to the present invention, the term "monobasic nicotine salt" is used to describe nicotine salts of monobasic acids.

[0095] Generally, aerosol-generating element can contain up to about 10 weight percent nicotine.Considering the application of the aerosol-generating element of the present invention as a substrate in an aerosol-generating article, this is advantageous because the content of nicotine in the film can be increased and adjusted to optimize the delivery of nicotine in aerosol form to consumers.Compared to existing aerosol-generating substrates based on the use of tobacco plants, this advantageously allows a higher content of nicotine per volume of substrate (element(s)) or per weight of substrate (element(s)), which may be desirable from the viewpoint of production.

[0096] Preferably, the aerosol-generating element contains at least about 0.5 percent nicotine by weight. More preferably, the aerosol-generating element contains at least about 1 percent nicotine by weight. Even more preferably, the aerosol-generating element contains at least about 2 percent nicotine by weight.

[0097] Preferably, the aerosol-generating element contains about 8 weight percent or less of nicotine. More preferably, the aerosol-generating element contains about 6 weight percent or less of nicotine. Even more preferably, the aerosol-generating element contains about 5 weight percent or less of nicotine. Most preferably, the aerosol-generating element contains about 4 weight percent or less of nicotine.

[0098] In some embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 10 weight percent nicotine, more preferably from about 1 weight percent to about 10 weight percent nicotine, and even more preferably from about 2 weight percent to about 10 weight percent nicotine.

[0099] In other embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 8 weight percent nicotine, more preferably from about 1 weight percent to about 8 weight percent nicotine, and even more preferably from about 2 weight percent to about 8 weight percent nicotine.

[0100] In a further embodiment, the aerosol-generating element contains between about 0.5 percent and about 6 percent by weight of nicotine, more preferably between about 1 percent and about 6 percent by weight of nicotine, and even more preferably between about 2 percent and about 6 percent by weight of nicotine.

[0101] In still further embodiments, the aerosol-generating element contains between about 0.5 percent and about 5 percent by weight of nicotine, more preferably between about 1 percent and about 5 percent by weight of nicotine, and even more preferably between about 2 percent and about 5 percent by weight of nicotine.

[0102] In particularly preferred embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 4 weight percent nicotine, more preferably from about 1 weight percent to about 4 weight percent nicotine, and even more preferably from about 2 weight percent to about 4 weight percent nicotine.

[0103] Preferably, the aerosol-generating element contains at least about 0.5 milligrams of nicotine. More preferably, the aerosol-generating element contains at least about 1 milligram of nicotine. Even more preferably, the aerosol-generating element contains at least about 1.5 milligrams of nicotine. In particularly preferred embodiments, the aerosol-generating element contains at least about 2 milligrams of nicotine, and most preferably at least about 2.5 milligrams of nicotine.

[0104] The aerosol-generating element may contain up to about 6 milligrams of nicotine. Preferably, the aerosol-generating element contains about 5 milligrams or less of nicotine. More preferably, the aerosol-generating element contains about 4.5 milligrams or less of nicotine. Even more preferably, the aerosol-generating element contains about 4 milligrams or less of nicotine. In a particularly preferred embodiment, the aerosol-generating element contains about 3.5 milligrams or less of nicotine, and most preferably, about 3 milligrams or less of nicotine.

[0105] In some preferred embodiments, the aerosol-generating formulation dispersed within the solid continuous matrix structure of the aerosol-generating element comprises a cannabinoid compound.Preferably, the cannabinoid compound is selected from CBD and THC.More preferably, the cannabinoid compound is CBD.

[0106] The aerosol-generating component may contain up to about 10 weight percent CBD. Preferably, the aerosol-generating component contains at least about 0.5 weight percent CBD. More preferably, the aerosol-generating film contains at least about 1 weight percent CBD. Even more preferably, the aerosol-generating film contains at least about 2 weight percent CBD.

[0107] Preferably, the aerosol-generating film comprises no more than about 6 weight percent CBD. More preferably, the aerosol-generating film comprises no more than about 5 weight percent CBD. Even more preferably, the aerosol-generating film comprises no more than about 4 weight percent CBD.

[0108] In some embodiments, the aerosol-generating element contains from about 0.5 percent to about 10 percent by weight CBD, more preferably from about 1 percent to about 10 percent by weight CBD, and even more preferably from about 2 percent to about 10 percent by weight CBD.

[0109] In other embodiments, the aerosol-generating element contains from about 0.5 percent to about 8 percent by weight CBD, more preferably from about 1 percent to about 8 percent by weight CBD, and even more preferably from about 2 percent to about 8 percent by weight CBD.

[0110] In a further embodiment, the aerosol-generating element comprises from about 0.5 percent to about 6 percent by weight CBD, more preferably from about 1 percent to about 6 percent by weight CBD, and even more preferably from about 2 percent to about 6 percent by weight CBD.

[0111] In yet a further embodiment, the aerosol-generating element comprises from about 0.5 percent to about 5 percent by weight CBD, more preferably from about 1 percent to about 5 percent by weight CBD, and even more preferably from about 2 percent to about 5 percent by weight CBD.

[0112] In particularly preferred embodiments, the aerosol-generating element contains from about 0.5 percent to about 4 percent CBD by weight, more preferably from about 1 percent to about 4 percent CBD by weight, and even more preferably from about 2 percent to about 4 percent nicotine by weight.

[0113] An aerosol-generating element according to the present invention may be a substantially tobacco-free aerosol-generating element.

[0114] As used herein in the context of the present invention, the term "substantially tobacco-free aerosol-generating element" describes an aerosol-generating element having a tobacco content of less than 1 percent by weight. For example, the aerosol-generating element may have a tobacco content of less than about 0.75 percent by weight, less than about 0.5 percent by weight, or less than about 0.25 percent by weight.

[0115] The aerosol-generating element may be a tobacco-free aerosol-generating element.

[0116] As used herein in connection with the present invention, the term "tobacco-free aerosol-generating element" describes an aerosol-generating element that has zero percent tobacco content by weight.

[0117] In some embodiments, the aerosol-generating components include tobacco material or non-tobacco plant material or plant extracts. By way of example, the aerosol-generating components may include tobacco particles, such as tobacco lamina particles, and other botanical particles, such as cloves and eucalyptus.

[0118] In some embodiments, the aerosol-generating formulation dispersed within the continuous solid matrix structure further comprises an acid. More preferably, the aerosol-generating formulation dispersed within the continuous solid matrix structure comprises one or more organic acids. Even more preferably, the aerosol-generating formulation dispersed within the continuous solid matrix structure comprises one or more carboxylic acids.

[0119] Carboxylic acids suitable for use in the aerosol-generating formulation of the aerosol-generating element according to the present invention include, but are not limited to, 2-ethylbutyric acid, acetic acid, adipic acid, benzoic acid, butyric acid, cinnamic acid, cycloheptane-carboxylic acid, fumaric acid, glycolic acid, hexanoic acid, lactic acid, levulinic acid, malic acid, myristic acid, octanoic acid, oxalic acid, propanoic acid, pyruvic acid, succinic acid, and undecanoic acid.

[0120] In a particularly preferred embodiment, the acid is lactic acid or levulinic acid or benzoic acid or fumaric acid or acetic acid. Most preferably, the acid is lactic acid.

[0121] The inclusion of an acid is particularly preferred in embodiments of the aerosol-generating element in which the aerosol-generating formulation dispersed within the continuous solid matrix structure includes nicotine, since it has been observed that the presence of an acid may stabilize species dissolved in the aerosol-generating formulation, such as those with nicotine and other plant extracts. Without intending to be bound by theory, it is understood that the acid may interact with the nicotine molecule, resulting in the stabilization of protonated nicotine. Since protonated nicotine is non-volatile, it is more easily found in the liquid or particle phase, rather than in the vapor phase of the aerosol obtained by heating the aerosol-generating element. Thus, the loss of nicotine during the manufacture of the aerosol-generating element can be minimized, advantageously ensuring a higher and better controlled delivery of nicotine to the consumer.

[0122] The aerosol-generating element may contain up to about 10 percent by weight of acid.

[0123] Preferably, the aerosol-generating component contains at least about 0.5 weight percent acid. More preferably, the aerosol-generating component contains at least about 1 weight percent acid. Even more preferably, the aerosol-generating component contains at least about 2 weight percent acid.

[0124] Preferably, the aerosol-generating component contains no more than about 8 weight percent acid. More preferably, the aerosol-generating component contains no more than about 6 weight percent acid. Even more preferably, the aerosol-generating component contains no more than about 5 weight percent acid. Most preferably, the aerosol-generating component contains no more than about 4 weight percent acid.

[0125] In some embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 10 weight percent acid, more preferably from about 1 weight percent to about 10 weight percent acid, and even more preferably from about 2 weight percent to about 10 weight percent acid.

[0126] In other embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 8 weight percent acid, more preferably from about 1 weight percent to about 8 weight percent acid, and even more preferably from about 2 weight percent to about 8 weight percent acid.

[0127] In a further embodiment, the aerosol-generating element contains from about 0.5 weight percent to about 6 weight percent acid, more preferably from about 1 weight percent to about 6 weight percent acid, and even more preferably from about 2 weight percent to about 6 weight percent acid.

[0128] In yet a further embodiment, the aerosol-generating element comprises from about 0.5 weight percent to about 5 weight percent acid, more preferably from about 1 weight percent to about 5 weight percent acid, and even more preferably from about 2 weight percent to about 5 weight percent acid.

[0129] In particularly preferred embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 4 weight percent acid, more preferably from about 1 weight percent to about 4 weight percent acid, and even more preferably from about 2 weight percent to about 4 weight percent acid.

[0130] When the aerosol-generating solution contains nicotine, the molar ratio of acid to nicotine is preferably from about 0.5:1 to about 2:1, more preferably from about 0.75:1 to about 1.5:1, and most preferably about 1:1.

[0131] When a polyacid, such as a polycarboxylic acid, is used, a molar ratio of acid groups to nicotine of preferably about 0.5:1 to about 2:1, more preferably about 0.75:1 to about 1.5:1, and most preferably about 1:1, may be provided. Thus, the use of a polyacid allows for the use of less weight of acid while still providing the same level of protonation of nicotine. In a preferred embodiment, the aerosol-generating component comprises at least about 0.5 weight percent levulinic acid. More preferably, the aerosol-generating component comprises at least about 1 weight percent levulinic acid. Even more preferably, the aerosol-generating component comprises at least about 2 weight percent levulinic acid.

[0132] Preferably, the aerosol-generating components contain no more than about 8 percent by weight levulinic acid. More preferably, the aerosol-generating components contain no more than about 6 percent by weight levulinic acid. Even more preferably, the aerosol-generating components contain no more than about 5 percent by weight levulinic acid. Most preferably, the aerosol-generating components contain no more than about 4 percent by weight levulinic acid.

[0133] In some embodiments, the aerosol-generating element comprises from about 0.5 weight percent to about 10 weight percent levulinic acid, more preferably from about 1 weight percent to about 10 weight percent levulinic acid, and even more preferably from about 2 weight percent to about 10 weight percent levulinic acid.

[0134] In other embodiments, the aerosol-generating components include from about 0.5 weight percent to about 8 weight percent levulinic acid, more preferably from about 1 weight percent to about 8 weight percent levulinic acid, and even more preferably from about 2 weight percent to about 8 weight percent levulinic acid.

[0135] In a further embodiment, the aerosol-generating components include from about 0.5 weight percent to about 6 weight percent levulinic acid, more preferably from about 1 weight percent to about 6 weight percent levulinic acid, and even more preferably from about 2 weight percent to about 6 weight percent levulinic acid.

[0136] In still further embodiments, the aerosol-generating components include from about 0.5 weight percent to about 5 weight percent levulinic acid, more preferably from about 1 weight percent to about 5 weight percent levulinic acid, and even more preferably from about 2 weight percent to about 5 weight percent levulinic acid.

[0137] In particularly preferred embodiments, the aerosol-generating components contain from about 0.5 weight percent to about 4 weight percent levulinic acid, more preferably from about 1 weight percent to about 4 weight percent levulinic acid, and even more preferably from about 2 weight percent to about 4 weight percent levulinic acid.

[0138] In other preferred embodiments, the aerosol-generating components contain at least about 0.5 percent by weight lactic acid. More preferably, the aerosol-generating components contain at least about 1 percent by weight lactic acid. Even more preferably, the aerosol-generating components contain at least about 2 percent by weight lactic acid.

[0139] Preferably, the aerosol-generating components contain no more than about 8 percent by weight lactic acid. More preferably, the aerosol-generating components contain no more than about 6 percent by weight lactic acid. Even more preferably, the aerosol-generating components contain no more than about 5 percent by weight lactic acid. Most preferably, the aerosol-generating components contain no more than about 4 percent by weight lactic acid.

[0140] In some embodiments, the aerosol-generating element comprises from about 0.5 weight percent to about 10 weight percent lactic acid, more preferably from about 1 weight percent to about 10 weight percent lactic acid, and even more preferably from about 2 weight percent to about 10 weight percent lactic acid.

[0141] In other embodiments, the aerosol-generating element comprises from about 0.5 weight percent to about 8 weight percent lactic acid, more preferably from about 1 weight percent to about 8 weight percent lactic acid, and even more preferably from about 2 weight percent to about 8 weight percent lactic acid.

[0142] In a further embodiment, the aerosol-generating element comprises from about 0.5 weight percent to about 6 weight percent lactic acid, more preferably from about 1 weight percent to about 6 weight percent lactic acid, and even more preferably from about 2 weight percent to about 6 weight percent lactic acid.

[0143] In yet a further embodiment, the aerosol-generating element comprises from about 0.5 weight percent to about 5 weight percent lactic acid, more preferably from about 1 weight percent to about 5 weight percent lactic acid, and even more preferably from about 2 weight percent to about 5 weight percent lactic acid.

[0144] In particularly preferred embodiments, the aerosol-generating element contains from about 0.5 weight percent to about 4 weight percent lactic acid, more preferably from about 1 weight percent to about 4 weight percent lactic acid, and even more preferably from about 2 weight percent to about 4 weight percent lactic acid.

[0145] Aerosol-generating elements according to the present invention preferably contain no more than about 25 percent by weight water.

[0146] More preferably, the aerosol-generating components contain no more than about 20 percent water by weight. Even more preferably, the aerosol-generating components contain no more than about 15 percent water by weight.

[0147] Aerosol-generating elements according to the invention preferably contain at least about 2.5 percent water by weight. More preferably, aerosol-generating elements according to the invention preferably contain at least about 5 percent water by weight. Even more preferably, aerosol-generating elements according to the invention preferably contain at least about 7.5 percent water by weight. Most preferably, aerosol-generating elements according to the invention preferably contain at least about 10 percent water by weight.

[0148] Generally, it is observed that the presence of some water contributes to imparting desirable stability to the aerosol-generating element. At the same time, a residual water content of 25 weight percent or less is desirable, since it is possible to obtain an aerosol-generating element that is substantially not sticky. Furthermore, when the aerosol-generating element is heated with a low water content, it is possible to provide the consumer with an aerosol enriched with polyhydric alcohols and alkaloids or cannabinoid compounds, such as nicotine.

[0149] In some embodiments, aerosol-generating elements according to the invention contain from about 2.5 percent to about 25 percent water by weight. Preferably, aerosol-generating elements according to the invention contain from about 5 percent to about 25 percent water by weight. More preferably, aerosol-generating elements according to the invention contain from about 7.5 percent to about 25 percent water by weight. Most preferably, aerosol-generating elements according to the invention contain from about 10 percent to about 25 percent water by weight.

[0150] In other embodiments, aerosol-generating elements according to the invention contain from about 2.5 percent to about 20 percent water by weight. Preferably, aerosol-generating elements according to the invention contain from about 5 percent to about 20 percent water by weight. More preferably, aerosol-generating elements according to the invention contain from about 7.5 percent to about 20 percent water by weight. Most preferably, aerosol-generating elements according to the invention contain from about 10 percent to about 20 percent water by weight.

[0151] In further embodiments, aerosol-generating elements according to the invention contain from about 2.5 percent to about 15 percent water by weight. Preferably, aerosol-generating elements according to the invention contain from about 5 percent to about 15 percent water by weight. More preferably, aerosol-generating elements according to the invention contain from about 7.5 percent to about 15 percent water by weight. Most preferably, aerosol-generating elements according to the invention contain from about 10 percent to about 15 percent water by weight.

[0152] In yet a further embodiment, aerosol-generating elements according to the invention contain from about 2.5 percent to about 10 percent water by weight. Preferably, aerosol-generating elements according to the invention contain from about 5 percent to about 10 percent water by weight. More preferably, aerosol-generating elements according to the invention contain from about 7.5 percent to about 10 percent water by weight. Most preferably, aerosol-generating elements according to the invention contain from about 10 percent to about 10 percent water by weight.

[0153] Aerosol-generating elements according to the present invention preferably have a water activity of about 0.7 or less.

[0154] The term "water activity" is used herein with reference to the present invention to indicate the ratio of the partial water vapor pressure at equilibrium with the aerosol-generating element to the water vapor saturation pressure at equilibrium with pure water at the same temperature. Thus, water activity is a dimensionless quantity between 0, which corresponds to a completely anhydrous substance, and 1, which corresponds to pure salt-free water. Methods for measuring the water activity of an aerosol-generating element according to the present invention are described in the 2017 publication of ISO 18787 (Foodstuffs-Determination of water activity).

[0155] The aerosol-generating element according to the present invention may optionally further comprise a flavouring. The flavouring may be in liquid or solid form. Optionally, the flavouring may be provided in a microencapsulated form, where the flavouring is released upon heating.

[0156] The aerosol-generating component preferably contains at least about 0.05 weight percent flavorant, more preferably at least about 0.1 weight percent flavorant, based on the total weight of the aerosol-generating component. The aerosol-generating component preferably contains no more than about 1 weight percent flavorant, more preferably no more than about 0.5 weight percent flavorant, based on the total weight of the aerosol-generating component.

[0157] In some embodiments, the aerosol-generating element contains from about 0.05 weight percent to about 1 weight percent of flavorant, preferably from about 0.05 weight percent to about 0.5 weight percent of flavorant, based on the total weight of the aerosol-generating element. In other embodiments, the aerosol-generating element contains from about 0.1 weight percent to about 1 weight percent of flavorant, preferably from about 0.1 weight percent to about 0.5 weight percent of flavorant, based on the total weight of the aerosol-generating element.

[0158] Suitable flavoring agents for use in the aerosol-generating elements according to the present invention include, but are not limited to, menthol, mints such as peppermint or spearmint, cocoa, licorice, fruits (such as citrus), gamma octalactone, vanillin, spices (such as cinnamon), methyl salicylate, linalool, eugenol, eucalyptol, bergamot oil, eugenol oil, geranium oil, lemon oil, ginger oil, and tobacco tobacco flavors.

[0159] The aerosol generating element according to the present invention may optionally further comprise a plurality of susceptor particles. The susceptor particles are electrically conductive particles capable of converting electromagnetic energy and converting it to heat. When located in an alternating electromagnetic field, eddy currents are induced in the susceptor particles and hysteresis losses occur, causing the susceptor to heat up. The susceptor particles are located in thermal contact or in close thermal proximity with the aerosol-generating formulation of the aerosol-generating element, so that the aerosol-generating formulation is heated by the susceptor particles such that an aerosol is formed.

[0160] Thus, including susceptor particles in the aerosol-generating solution provides an aerosol-generating element that is inductively heatable. When the aerosol-generating element is used in an apparatus that includes an induction heater, altering the electromagnetic field generated by one or more induction coils of the induction heating device heats the susceptor particles, which then are transferred, primarily by thermal conduction, to the aerosol-generating formulation surrounding the aerosol-generating element.

[0161] The susceptor particles may be formed of any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-generating formulation. Preferred susceptor particles include metal or carbon. Preferred susceptor particles may include or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel, or stainless steel. Suitable susceptor particles may be or include aluminum. Preferred susceptor particles may be heated to a temperature of more than 250 degrees Celsius. Suitable susceptor particles may include a non-metallic core, such as a ceramic core with a metal layer disposed thereon, with a metal track formed on the surface. The susceptor particles may have a protective outer layer, such as a protective ceramic layer or a protective glass layer, that encapsulates the susceptor particles. The susceptor particles may include a protective coating formed of glass, ceramic, or an inert metal formed on a core of susceptor material.

[0162] The susceptor particles can have an average particle size of up to about 60 micrometers. For example, the susceptor particles can have an average particle size of about 50 micrometers or less, or about 40 micrometers or less, or about 35 micrometers or less.

[0163] Typically, in an aerosol-generating solution for use in a method according to the invention, the susceptor particles have an average particle size of at least about 1 micrometer, or at least about 2 micrometers, or at least about 5 micrometers, or at least about 10 micrometers.

[0164] For example, the susceptor particles in the aerosol-generating solution may have an average particle size of from about 1 micrometer to about 60 micrometers, or from about 2 millimeters to about 50 micrometers, or from about 5 micrometers to about 40 micrometers, or from about 10 micrometers to about 35 micrometers.

[0165] Optionally, the aerosol-generating formulation dispersed in the solid continuous matrix structure of the aerosol-generating element according to the present invention may further comprise a solid filler. The inclusion of a solid filler may advantageously improve the physical properties of the aerosol-generating element. Without intending to be bound by theory, it is understood that the inclusion of a solid filler during the manufacture of the aerosol-generating element may facilitate the control of the properties of the aerosol-generating solution during the step of forming the individual portions of the aerosol-generating solution. Suitable solid fillers are known to those skilled in the art.

[0166] For example, the aerosol-generating element according to the present invention may further include particles of plant material obtained by crushing, grinding, or comminuting the plant material. By way of example, the aerosol-generating element may further include tea particles, coffee particles, clove particles, eucalyptus particles, star anise particles, ginger particles. Additionally or alternatively, the aerosol-generating element according to the present invention may further include particles obtained by crushing, grinding, or comminuting one or more of tobacco leaf lamina and tobacco leaf stem. The inventors of the present invention have found that by incorporating such plant particles into the aerosol-generating element, an aerosol that advantageously provides a novel sensory experience can be produced. Such an aerosol may provide a unique flavor and provide an increased level of body.

[0167] In embodiments in which the aerosol-generating element comprises plant particles, the aerosol-generating element may comprise up to about 40 percent by weight of plant particles. Preferably, the aerosol-generating element comprises no more than about 35 percent by weight of plant particles. More preferably, the aerosol-generating element comprises no more than about 30 percent by weight of plant particles. Even more preferably, the aerosol-generating element comprises no more than about 25 percent by weight of plant particles.

[0168] In some embodiments, the aerosol-generating element comprises at least about 1 percent by weight of plant particles. Preferably, the aerosol-generating element comprises at least about 2 percent by weight of plant particles. More preferably, the aerosol-generating element comprises at least about 5 percent by weight of plant particles. Even more preferably, the aerosol-generating element comprises at least about 10 percent by weight of plant particles.

[0169] In some preferred embodiments, the aerosol-generating element comprises between about 1 percent and about 40 percent plant particles by weight. Preferably, the aerosol-generating element comprises between about 2 percent and about 40 percent plant particles by weight. More preferably, the aerosol-generating element comprises between about 5 percent and about 40 percent plant particles by weight. Even more preferably, the aerosol-generating element comprises between about 10 percent and about 40 percent plant particles by weight.

[0170] In other embodiments, the aerosol-generating element comprises between about 1 percent and about 35 percent plant particles by weight. Preferably, the aerosol-generating element comprises between about 2 percent and about 35 percent plant particles by weight. More preferably, the aerosol-generating element comprises between about 5 percent and about 35 percent plant particles by weight. Even more preferably, the aerosol-generating element comprises between about 10 percent and about 35 percent plant particles by weight.

[0171] In further embodiments, the aerosol-generating element comprises between about 1 percent and about 30 percent by weight of plant particles. Preferably, the aerosol-generating element comprises between about 2 percent and about 30 percent by weight of plant particles. More preferably, the aerosol-generating element comprises between about 5 percent and about 30 percent by weight of plant particles. Even more preferably, the aerosol-generating element comprises between about 10 percent and about 30 percent by weight of plant particles.

[0172] In still further embodiments, the aerosol-generating element comprises between about 1 percent and about 25 percent by weight of plant particles. Preferably, the aerosol-generating element comprises between about 2 percent and about 25 percent by weight of plant particles. More preferably, the aerosol-generating element comprises between about 5 percent and about 25 percent by weight of plant particles. Even more preferably, the aerosol-generating element comprises between about 10 percent and about 25 percent by weight of plant particles.

[0173] In embodiments in which the aerosol-generating element comprises plant particles, the plant particles may have an average particle size of up to about 60 micrometers. In aerosol-generating elements according to the invention, the plant particles preferably have an average particle size of about 50 micrometers or less. More preferably, in aerosol-generating elements according to the invention, the plant particles have an average particle size of about 40 micrometers or less. Even more preferably, in aerosol-generating elements according to the invention, the plant particles have an average particle size of about 30 micrometers or less.

[0174] Typically, in an aerosol-generating element according to the invention, the plant particles have an average particle size of at least about 1 micrometer. Preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of at least about 2 micrometers. More preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of at least about 5 micrometers. Even more preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of at least about 10 micrometers.

[0175] In some preferred embodiments, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 1 millimeter to about 60 micrometers. Preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 2 millimeters to about 60 micrometers. More preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 5 millimeters to about 60 micrometers. Even more preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 10 millimeters to about 60 micrometers.

[0176] In another embodiment, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 1 millimeter to about 50 micrometers. In an aerosol-generating element according to the invention, the plant particles preferably have an average particle size of about 2 millimeters to about 50 micrometers. In an aerosol-generating element according to the invention, the plant particles more preferably have an average particle size of about 5 millimeters to about 50 micrometers. In an aerosol-generating element according to the invention, the plant particles even more preferably have an average particle size of about 10 millimeters to about 50 micrometers.

[0177] In a further embodiment, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 1 millimeter to about 40 micrometers. Preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 2 millimeters to about 40 micrometers. More preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 5 millimeters to about 40 micrometers. Even more preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 10 millimeters to about 40 micrometers.

[0178] In yet a further embodiment, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 1 millimeter to about 30 micrometers. Preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 2 millimeters to about 30 micrometers. More preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 5 millimeters to about 30 micrometers. Even more preferably, in an aerosol-generating element according to the invention, the plant particles have an average particle size of about 10 millimeters to about 30 micrometers.

[0179] Aerosol-generating elements according to the present invention may have an equivalent diameter of at least about 0.5 millimeters.

[0180] The term "equivalent diameter of an aerosol-generating element" is used herein to indicate the diameter of a sphere having the same volume as the aerosol-generating element. In general, the aerosol-generating element may have any shape, although a spherical or quasi-spherical shape, such as an ovoid or ellipsoidal shape, is preferred. For an aerosol-generating element having a spherical shape and a circular transverse cross-section, the equivalent diameter is the diameter of the cross-section of the aerosol-generating element.

[0181] Preferably, the aerosol-generating elements have an equivalent diameter of at least about 1 millimeter. More preferably, the aerosol-generating elements have an equivalent diameter of at least about 2 millimeters. Even more preferably, the aerosol-generating elements have an equivalent diameter of at least about 3 millimeters.

[0182] Aerosol-generating elements according to the present invention preferably have an equivalent diameter of about 8 millimeters or less. More preferably, the aerosol-generating elements have an equivalent diameter of about 6 millimeters or less. Even more preferably, the aerosol-generating elements have an equivalent diameter of about 5 millimeters or less.

[0183] In some embodiments, the aerosol generating element has an equivalent diameter of about 0.5 millimeters to about 8 millimeters, preferably about 1 millimeter to about 8 millimeters, more preferably about 2 millimeters to about 8 millimeters, and even more preferably about 3 millimeters to about 8 millimeters.

[0184] In other embodiments, the aerosol-generating elements have an equivalent diameter of from about 0.5 millimeters to about 6 millimeters, preferably from about 1 millimeter to about 6 millimeters, more preferably from about 2 millimeters to about 6 millimeters, and even more preferably from about 3 millimeters to about 6 millimeters.

[0185] In a further embodiment, the aerosol-generating elements have an equivalent diameter of about 0.5 millimeters to about 5 millimeters, preferably about 1 millimeter to about 5 millimeters, more preferably about 2 millimeters to about 5 millimeters, and even more preferably about 3 millimeters to 5 millimeters.

[0186] In particularly preferred embodiments, the aerosol-generating elements have an equivalent diameter of about 4 millimeters or about 4.5 millimeters.

[0187] Aerosol-generating elements according to the present invention may have an ellipticity of up to about 35 percent.

[0188] As used herein with reference to the present invention, the term "ovality" refers to the degree of deviation from a perfect circle. Ovality is expressed as a percentage and has the mathematical definition as follows:

number

number

[0189] To determine the ellipticity of an object, such as an aerosol-generating element, the object is viewed along a direction substantially perpendicular to the cross-section of the aerosol-generating element. As an example, the aerosol-generating element may be positioned on a transparent stage such that an image of the aerosol-generating element is recorded by a suitable imaging device located below the stage. Dimension "a" is taken as the maximum outer diameter of the image of the aerosol-generating element, and dimension "b" is taken as the minimum outer diameter of the image of the aerosol-generating element. The process is repeated for a total of ten aerosol-generating elements having the same composition and prepared by the same process under the same operating conditions. The number average of the ten ellipticity measurements is recorded as the ellipticity of that aerosol-generating element.

[0190] Aerosol-generating elements according to the invention preferably have an ellipse of about 30 percent or less. More preferably, aerosol-generating elements according to the invention have an ellipse of about 25 percent or less. Even more preferably, aerosol-generating elements according to the invention have an ellipse of about 20 percent or less.

[0191] Aerosol-generating elements according to the present invention typically have an ellipticity of at least about 1 percent. Preferably, the aerosol-generating elements have an ellipticity of at least 2 percent. More preferably, the aerosol-generating elements have an ellipticity of at least 3 percent. Even more preferably, the aerosol-generating elements have an ellipticity of at least 4 percent.

[0192] In some embodiments, the aerosol-generating element has an ellipticity of from about 1 percent to about 30 percent, more preferably from about 2 percent to about 30 percent, more preferably from about 3 percent to about 30 percent, and even more preferably from about 4 percent to about 30 percent.

[0193] In other embodiments, the aerosol-generating element has an ellipticity of from about 1 percent to about 25 percent, more preferably from about 2 percent to about 25 percent, more preferably from about 3 percent to about 25 percent, and even more preferably from about 4 percent to about 25 percent.

[0194] In further embodiments, the aerosol-generating element has an ellipticity of from about 1 percent to about 20 percent, more preferably from about 2 percent to about 30 percent, more preferably from about 3 percent to about 20 percent, and even more preferably from about 4 percent to about 20 percent.

[0195] The aerosol-generating article according to the present invention has a maximum diameter of 25 cm -1 The exposed surface area to volume ratio may be

[0196] As used herein with reference to the present invention, the phrase "exposed surface area to volume ratio" refers to the ratio between the total external surface area of ​​the aerosol-generating element that is exposed and available for heat and mass exchange, and the total volume of the aerosol-generating element.

[0197] Because the aerosol-generating elements according to the present invention have low ellipticity and can be assimilated to a spherical object, the volume of an aerosol-generating element according to the present invention can be represented by the following formula:

number

[0198] The exposed surface area of ​​an aerosol-generating element according to the present invention may be estimated by the following formula:

number

[0199] Dimension R eq denotes the equivalent radius of the aerosol-generating element.

[0200] The aerosol-generating article has a diameter of at least about 0.083 cm -1Preferably, the aerosol-generating article has an exposed surface area to volume ratio of at least about 0.166 cm -1 More preferably, the aerosol-generating article has an exposed surface area to volume ratio of at least about 0.249 cm -1 It is even more preferred that the exposed surface area to volume ratio is:

[0201] Aerosol-generating items are approximately 24 cm -1 It is preferred that the aerosol-generating article have an exposed surface area to volume ratio of about 20 cm -1 More preferably, the aerosol-generating article has an exposed surface area to volume ratio of about 16 cm -1 It is even more preferred to have the following exposed surface area to volume ratio:

[0202] In some embodiments, the aerosol-generating article has a diameter of about 0.083 cm -1 ~Approx. 24cm -1 , more preferably about 0.166 cm -1 ~Approx. 24cm -1 , and even more preferably, about 0.249 cm -1 ~Approx. 24cm -1 The exposed surface area to volume ratio is

[0203] In another embodiment, the aerosol-generating article has a diameter of about 0.083 cm. -1 ~about 20cm -1 , more preferably about 0.166 cm -1 ~about 20cm -1 , and even more preferably, about 0.249 cm -1 ~about 20cm -1 The exposed surface area to volume ratio is

[0204] In a further embodiment, the aerosol-generating article has a diameter of about 0.083 cm -1 ~Approx. 16cm -1 , more preferably about 0.166 cm -1 ~Approx. 16cm -1 , and even more preferably, about 0.249 cm -1 ~Approx. 16cm -1 The exposed surface area to volume ratio is

[0205] In some embodiments, the aerosol-generating element according to the present invention may be coated. In fact, an outer coating layer may optionally be provided on the aerosol-generating element as described above. This may be achieved by a coating step, which may take place before or after the coating step. An optional coating step may be incorporated after the coating step.

[0206] The provision of a coating layer on an aerosol generating element may be desirable for many different reasons. For example, the coating layer may advantageously limit the transmission of oxygen or water vapor to the aerosol generating element, which may help to extend the shelf life of the aerosol generating element. Alternatively, or in addition, the coating layer may help to protect the structural integrity of the aerosol generating element or provide improved smoothness of the aerosol generating element. In certain embodiments, a relatively frangible coating layer may be added to an aerosol generating element that is adapted to be broken by the consumer prior to use. Thus, this type of coating layer may provide a tactile and audible indication to the consumer that the aerosol generating element has been activated. Alternatively, or in addition, the provision of a coating layer on an aerosol generating element may be used to adjust the color of the aerosol generating element, for example, to provide a visual indication of a property of the aerosol generating element, such as flavor or nicotine content.

[0207] Suitable types of coating materials will be known to those skilled in the art. For example, a coating layer of a water-soluble film former, such as HPMC or shellac, may be added to the aerosol-generating element. Such a film former will adhere strongly to the surface of the aerosol-generating element. In a further example, a coating layer of sodium alginate may be added, which crosslinks with any residual calcium ions on the surface of the aerosol-generating element to form a thin film of calcium alginate.

[0208] The coating layer may be applied to the exterior surface of the aerosol-generating element using a variety of coating techniques. Suitable equipment and techniques will be known to those skilled in the art.

[0209] Aerosol-generating elements as described above may find use as aerosol-generating substrates for aerosol-generating articles of the type in which the substrate is heated to release an inhalable aerosol, as opposed to articles in which the substrate is combusted to produce smoke.

[0210] Because the aerosol-generating elements according to the invention are easy to manufacture and are predetermined, so that individual amounts of the aerosol-generating formulation may be provided in encapsulated form, and because the composition of the aerosol-generating formulation, particularly with regard to the content of polyhydric alcohol, and alkaloid or cannabinoid compound, can be finely tuned and controlled, the aerosol-generating elements according to the invention are versatile and can be used as substrates in many arrangements.

[0211] As an example, a plurality of aerosol generating elements according to the invention may be provided within a cavity defined by a tubular element, such that the outer surfaces of the aerosol generating elements are exposed to the inside of a longitudinal airflow channel defined by the cavity. Upon heating, an aerosol may be generated from the aerosol generating elements, such that the aerosol is released into the airflow channel and may be drawn through the tubular element and into the consumer's mouth.

[0212] Thus, the aerosol generating elements as described above may find use in an aerosol generating system comprising one or more aerosol generating elements or articles as described above, and an electrically operated aerosol generating device. A suitable aerosol generating device comprises a heating element and a heating chamber configured to receive the one or more aerosol generating elements or articles such that the one or more aerosol generating elements are heated in the heating chamber by the heating element.

[0213] Upon heating, the aerosol-generating element according to the invention releases an aerosol containing the aerosol-generating formulation ingredients, including, inter alia, polyhydric alcohols and alkaloid or cannabinoid compounds. It has been found that when the aerosol-generating element according to the invention is heated to a temperature in the range of about 150 degrees Celsius to about 350 degrees Celsius, the aerosol-generating element loses weight without undergoing significant volumetric shrinkage. Furthermore, it has been found that when the aerosol-generating element according to the invention is heated to a temperature in the range of about 150 degrees Celsius to about 350 degrees Celsius and heat is supplied until no further weight loss is detected, the residual weight of the aerosol-generating element is typically less than 120 percent of the weight of the solid continuous matrix structure components, preferably less than 115 percent of the weight of the solid continuous matrix structure components, more preferably less than 115 percent of the weight of the solid continuous matrix structure components, and even more preferably less than 105 percent of the weight of the solid continuous matrix structure components.

[0214] Most preferably, when an aerosol-generating element according to the present invention is heated to a temperature in the range of about 150 degrees Celsius to about 350 degrees Celsius and heat is supplied until no further weight loss is detected, the residual weight of the aerosol-generating element substantially corresponds to the combined weight of the components of the solid continuous matrix structure.

[0215] One embodiment of the present invention will now be further described, by way of example only. EXAMPLES

[0216] An aerosol generating solution was formed from a mixture of the following components: [Table 1]

[0217] In the first step, sodium alginate is added to water to form a matrix polymer solution, then nicotine is added, followed by glycerin and finally levulinic acid.

[0218] The resulting aerosol generating solution is extruded through a 5 millimeter nozzle to form multiple droplets which are then dropped at room temperature from a height of 30 centimeters into a crosslinking solution having the following composition: [Table 2]

[0219] The droplets are left in the crosslinking solution for 25 minutes and then dried in a tray dryer at 25 degrees Celsius for 12 hours. The resulting dried aerosol-generating elements are in the form of solid spherical beads having a diameter of about 4.6 mm. Each bead has an approximate weight of 65 mg, a water activity of 0.4, and the following composition: [Table 3]

Claims

1. 1. An aerosol generating element for use in an aerosol generating article or system, the aerosol generating element comprising: a solid continuous matrix structure; an aerosol-generating formulation dispersed within the solid continuous matrix structure, wherein the aerosol-generating formulation is entrapped within the solid continuous matrix structure and releasable from the solid continuous matrix structure upon heating of the aerosol-generating element; the solid continuous matrix structure is an alginate matrix, and the aerosol-generating formulation dispersed within the solid continuous matrix structure is nicotine in an amount comprising 1 weight percent to 4 weight percent of the total weight of the aerosol-generating element; glycerin in an amount of 60 weight percent to 80 weight percent of the total weight of the aerosol-generating component; a carboxylic acid in an amount of 0.5 weight percent to 4 weight percent of the total weight of the aerosol-generating component; the balance being water, An aerosol-generating element, wherein the aerosol-generating formulation dispersed within the solid continuous matrix structure comprises at least 80 weight percent of the total weight of the aerosol-generating element, and the aerosol-generating element contains less than 15 weight percent water.

2. 2. The aerosol generating element of claim 1, wherein the aerosol generating formulation dispersed within the solid continuous matrix structure comprises at least 90 weight percent of the total weight of the aerosol generating element.

3. 3. The aerosol generating element of claim 1 or 2, wherein the carboxylic acid is lactic acid or levulinic acid.

4. 4. The aerosol-generating element of claim 1, comprising from 2 percent to 6 percent by weight of alginate.

5. An aerosol generating element described in any one of claims 1 to 4, containing less than 10 weight percent water.

6. 6. An aerosol generating element according to any one of claims 1 to 5, having an equivalent diameter of at least 0.5 millimetres.

7. An aerosol generating element described in any one of claims 1 to 6 having an equivalent diameter of 6 millimeters or less.

8. An aerosol generating element described in any one of claims 1 to 7, having an ellipticity of 2 percent to 30 percent.

9. An aerosol generating element as claimed in any one of claims 1 to 8, having an exposed surface area to volume ratio of from 0.083 cm -1 to 24 cm -1 .

Images