METHOD FOR PRODUCING AN AEROSOL GENERATING ELEMENT

Abstract

A method for producing an aerosol-generating element for an aerosol-generating article or system comprises the steps of: preparing a matrix polymer solution comprising a matrix-forming polymer in water; adding a plurality of aerosol-generating formulation components to the matrix polymer solution to form an aerosol-generating solution, wherein the aerosol-generating formulation components comprise a polyhydric alcohol and at least one alkaloid or cannabinoid; forming a discrete portion of the aerosol-generating solution; adding the discrete portion of the aerosol-generating solution to a multivalent cation crosslinking solution to crosslink the matrix-forming polymer; and removing the aerosol-generating element from the crosslinking solution and drying the aerosol-generating element.

Description

METHOD FOR PRODUCING AN AEROSOL GENERATING ELEMENT The present invention relates to a method for producing an aerosol generating element for use in an aerosol generating article or aerosol generating system. The present invention further relates to an aerosol generating element produced by said method. Aerosol-generating articles in which an aerosol-generating substrate, such as a nicotine-containing or tobacco-containing substrate, is heated rather than burned, are known in the art. Typically, in such heated smoking articles, an aerosol is generated by the transfer of heat from a heat source to a physically separate aerosol-generating material or substrate, 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 the heat transfer from the heat source and are carried in the air drawn through the article. As the released compounds cool, they condense to form an aerosol. A number of prior art documents describe aerosol-generating devices for the consumption of aerosol-generating articles. Such devices include, for example, electrically heated aerosol-generating devices in which an aerosol is generated by the transfer of heat from one or more electrical heating elements of the aerosol-generating device to the aerosol-generating substrate of a heated aerosol-generating article. In the past, substrates for heated aerosol-generating articles have often been produced using randomly oriented fragments, strands, or strips of tobacco material. Alternatively, bars for heated aerosol-generating articles formed from crinkled sheets of tobacco material have been described, by way of example, in International Patent Application WO-A-2012 / 164009. International patent application WO-A-2011 / 101164 describes alternative bars for heated aerosol-generating articles formed from strands of homogenized tobacco material. These bars can be formed by melting, rolling, calendering, or extruding a mixture comprising particulate tobacco and at least one aerosol former to form a sheet of homogenized tobacco material. In alternative embodiments, the bars of WO-A-2011 / 101164 can be formed from strands of homogenized tobacco material obtained by extruding a mixture comprising particulate tobacco. Qfrncnn / zznz / E / YiAi and at least one aerosol former to form continuous lengths of homogenized tobacco material. Alternative forms of nicotine-comprising substrates have also been described. For example, liquid nicotine compositions, often referred to as e-liquids, have been proposed. These liquid compositions can be heated, for instance, by means of an electrically resistive coil of an aerosol-generating device. Substrates of this type may require particular care in the manufacture of the containers holding the liquid composition to prevent inconvenient leaks. It has been previously proposed to provide an encapsulated nicotine formulation for use as an aerosol-generating substrate. However, encapsulating nicotine formulations has proven challenging. One reason for this is the preference for hydrophilic aerosol formers, such as glycerin and propylene glycol, in the nicotine formulation, making it difficult to encapsulate the formulation with commonly used hydrophilic encapsulation materials. With existing encapsulation techniques, a very high level of the hydrophilic encapsulation material is generally found to be required to produce a stable product. This, in turn, means that an insufficient amount of the nicotine formulation is delivered per unit volume, resulting in inefficient aerosol delivery from the encapsulated substrate. While hydrophobic encapsulation materials are available, they often require processing at relatively high temperatures, which risks degradation of the nicotine formulation during manufacturing. During use, the temperatures required to generate an aerosol from the nicotine formulation can be high enough to cause degradation of the hydrophobic encapsulation material. This can result in the release of unwanted compounds in the resulting aerosol, which may adversely impact its sensory profile. It would be advantageous to provide a novel method for producing an encapsulated aerosol-generating formulation, such as a nicotine-containing formulation, that provides an improved encapsulated substrate with greater stability and minimal leakage of the aerosol-generating formulation. It would be particularly advantageous to provide a method for producing an encapsulated substrate that holds a maximum aerosol-generating formulation with minimal encapsulation material, thus providing efficient aerosol delivery. Additionally, it would be advantageous to provide a method for producing an encapsulated substrate Qfrncnn / zznz / E / YiAi that provides a controlled supply of aerosol when heated. It would also be convenient to provide a method for producing an encapsulated substrate in a form that can be readily incorporated into an aerosol-generating article or device and easily heated to generate an aerosol. According to the present invention, a method is provided for producing an aerosol generating element comprising the steps of: preparing a matrix polymer solution comprising a matrix-forming polymer in water; adding a plurality of aerosol generating formulation components to the matrix polymer solution to form an aerosol generating solution, wherein the aerosol generating formulation components comprise a polyhydric alcohol and at least one alkaloid or cannabinoid; forming a discrete portion of the aerosol generating solution;adding the discrete portion of the aerosol-generating solution to a multivalent cation crosslinking solution to crosslink the matrix-forming polymer, thereby forming an aerosol-generating element having a continuous polymer matrix and an aerosol-generating formulation comprising the aerosol-generating formulation components dispersed within the continuous polymer matrix; and removing the aerosol-generating element from the crosslinking solution and drying the aerosol-generating element. The method as defined forms an aerosol generating element having a continuous polymer matrix and an aerosol generating formulation comprising the aerosol generating formulation components dispersed within the continuous polymer matrix. In accordance with the present invention, an aerosol generating element produced according to the method of the present invention, as defined above, is further provided, the aerosol generating element comprising at least 60 percent by weight of polyhydric alcohol, at least 0.5 percent by weight of nicotine and at least 0.5 percent by weight of acid. As used in the present description, the term “aerosol generating article” refers to an aerosol generating article for producing an aerosol comprising an aerosol generating substrate that is intended to be heated rather than burned in order to release volatile compounds that can form an aerosol. As used herein, the term “aerosol generating element” refers to a discrete, solid aerosol generating substrate comprising the aerosol generating formulation dispersed and encapsulated within a crosslinked polymer matrix. The structure and composition of the aerosol generating element Qfrncnn / zznz / E / YiAi will be described in more detail below. An aerosol generating element according to the present invention can be used as an aerosol generating substrate of an aerosol generating article. As used herein, the term “aerosol-generating substrate” refers to a substrate capable of releasing volatile compounds upon heating, which can then form an aerosol. In the present invention, the aerosol-generating substrate takes the form of an aerosol-generating element that encapsulates an aerosol-generating formulation comprising at least one alkaloid or cannabinoid and a polyhydric alcohol. The aerosol generated from the aerosol-generating formulation of aerosol-generating elements 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. A conventional cigarette is lit when a user applies an ignition source to one end of the cigarette and draws air through the other. The localized heat from the flame and the oxygen in the air drawn through the cigarette causes the end of the cigarette to ignite, and the resulting combustion produces inhalable smoke. In contrast, in heated aerosol-generating articles, an aerosol is generated by heating a flavor-generating substrate, such as a tobacco-based substrate or a substrate containing an aerosol former and a flavoring. Known heated aerosol-generating articles include, for example, electrically heated aerosol-generating articles and aerosol-generating articles in which an aerosol is generated by transferring heat from a fuel element or heat source to a physically separate aerosol-forming material. For example, aerosol-generating articles according to the invention may find particular application in aerosol-generating systems comprising an electrically heated aerosol-generating device having an internal heater adapted to supply heat to one or more discrete aerosol-generating substrate elements. As used herein with reference to the invention, the term “aerosol-generating device” is used to describe a device comprising a heating element that interacts with one or more aerosol-generating elements according to the invention to produce an aerosol. During use, volatile compounds are released from the element. Qfrncnn / zznz / E / YiAi or aerosol-generating elements by heat transfer and are carried in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the consumer. Substrates for heated aerosol-generating articles typically comprise an “aerosol former,” that is, a compound or mixture of compounds that, during use, facilitates aerosol formation and is preferably essentially resistant to thermal degradation at the operating temperature of the aerosol-generating article. Examples of suitable aerosol formers include: polyhydric alcohols, such as propylene glycol, 1,3-butanediol, and glycerin; esters of polyhydric alcohols, such as glycerol monoacetate, dicetate, or triacetate; and aliphatic esters of monocarboxylic, dicarboxylic, or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. The polyhydric alcohol in the aerosol-generating formulation of the aerosol-generating element produced according to the invention is also an aerosol former within the meaning set out above. As used herein, the term “aerosol generating formulation” refers to a formulation comprising a plurality of aerosol generating formulation components, which, upon heating from the aerosol generating element, will volatilize to produce an aerosol. The “aerosol generating solution” produced during the method of the present invention refers to a solution of the aerosol generating formulation components and the matrix-forming polymer in a suitable solvent. As used in this description, the term “matrix-forming polymer” refers to an encapsulation material in the form of a polymer that is capable of producing a three-dimensional polymer matrix as a result of crosslinking when the matrix-forming polymer comes into contact with a multivalent cation crosslinking solution. The resulting polymer matrix is ​​able to trap and retain the aerosol-generating formulation within its crosslinked structure. The nature of the crosslinked polymer matrix will be described in more detail below. As described above, the present invention provides a novel method for producing an aerosol generating element, wherein an aerosol generating formulation is encapsulated within a continuous polymer matrix structure. The aerosol generating element produced according to the invention provides a stable structure in which the aerosol generating formulation can be effectively retained, with minimal loss of the Qfrncnn / zznz / E / YiAi aerosol generating formulation components during the manufacture or storage of the aerosol generating element. Advantageously, the method according to the invention allows for efficient encapsulation of the aerosol-generating formulation using a significantly lower level of encapsulation material (corresponding to the matrix-forming polymer) than previously possible. This allows the levels of aerosol-generating formulation components, such as the alkaloid or cannabinoid and the polyhydric alcohol, to be maximized within the aerosol-generating element. Furthermore, the reduced proportion of encapsulation material allows the aerosol to be generated more efficiently upon heating, as less heating of the encapsulation material occurs. The polymer matrix of the aerosol-generating element provides an inert encapsulation structure to retain and immobilize the aerosol-generating formulation, which is stable when the aerosol-generating element is heated during use. The inventors have found that, when heated to temperatures in the range of 150°C to 350°C, aerosol-generating elements produced according to the present invention release an aerosol as they undergo a significant weight loss. However, this weight loss is not accompanied by an equally significant volume loss. Without wishing to be limited to theory, it is understood that, upon heating, the components of the aerosol-generating formulation originally dispersed and trapped within the continuous polymer matrix structure essentially vaporize and are released.On the other hand, the components of the continuous polymer matrix structure are essentially unaffected, and the continuous polymer matrix only shrinks partially while essentially retaining its 3D structure. As such, encapsulating the aerosol-generating formulation within the polymer-based matrix advantageously provides minimal or no adverse effects on the sensory profile of the aerosol generated upon heating. It has been found that the aerosol-generating element produced by the method of the present invention advantageously provides a controlled aerosol delivery. Furthermore, the aerosol delivery profile can be easily adjusted by controlling different parameters of the production method. For example, the aerosol delivery profile can be adjusted by altering the method to control parameters of the aerosol-generating element such as its size, shape, structure, and formulation. The aerosol generating element is in the form of a solid, independent object and Qfrncnn / zznz / E / YiAi discrete that is sufficiently stable and robust to be easily processed and introduced into an aerosol generating article using existing methods and techniques. As previously defined, in the method for producing an aerosol-generating element, an aerosol-generating solution is first prepared from a matrix polymer solution and the aerosol-generating formulation components. A discrete portion of the aerosol-generating solution is then added to a crosslinking solution to carry out crosslinking of the matrix polymer and the formation of the polymer matrix. The resulting aerosol-generating element is removed from the crosslinking solution and dried. Each of the steps of the method will now be described in greater detail. In a first step of the method of the present invention, a matrix polymer solution is formed, which is a solution of the matrix-forming polymer in water. Preferably, the matrix polymer solution comprises at least approximately 35 percent by weight of water, more preferably at least approximately 40 percent by weight of water. This water level ensures that the matrix-forming polymer dissolves sufficiently to provide a homogeneous solution. Preferably, the matrix polymer solution comprises at least approximately 40 percent by weight of the matrix-forming polymer, more preferably at least approximately 45 percent by weight of the matrix-forming polymer. This level of matrix-forming polymer has been found to provide a more stable aerosol-generating solution. The matrix-forming polymer can be a single polymer or a combination of two or more polymers, where one or more polymers are capable of forming a crosslinked matrix through an ionotropic gelation mechanism in a multivalent cation crosslinking solution. The crosslinking of the matrix-forming polymer is achieved by the reaction of the polymer with multivalent cations in the crosslinking solution, which form salt bridges to crosslink the polymer molecules. Suitable matrix-forming polymers would be known to the person skilled in the art. Preferably, the matrix-forming polymer comprises one or more polysaccharides, such as alginate or pectin, or a combination thereof. Particularly preferably, the matrix-forming polymer is alginate. Polysaccharides are particularly suitable for use in the present invention since they can be made water-insoluble and thermoset through crosslinking and are tasteless. Therefore, there is no adverse impact on the sensory properties of the aerosol generated from the aerosol-generating element. Qfrncnn / zznz / E / YiAi Alternative matrix-forming polymers suitable for use in methods according to the invention include, but are not limited to, chitosan, fibrin, collagen, gelatin, hyaluronic acid, dextran, and combinations thereof. Alternative matrix-forming polymers suitable for use in methods according to the 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). After the formation of the matrix polymer solution as described above, the plurality of aerosol-generating formulation components is added to the matrix polymer solution to form an aerosol-generating solution. The aerosol-generating formulation components comprise at least one alkaloid or cannabinoid and a polyhydric alcohol. Preferably, the aerosol-generating formulation components further comprise an acid. These components are described in more detail below. The aerosol-generating solution is therefore a solution containing the matrix polymer as well as the aerosol-generating formulation components. Preferably, the aerosol generating solution comprises at least approximately 1 percent by weight of the matrix forming polymer from the matrix polymer solution, more preferably at least approximately 1.5 percent by weight of the matrix forming polymer and more preferably at least approximately 2 percent by weight of the matrix forming polymer. Preferably, the aerosol generating solution comprises less than approximately 6 percent by weight of the matrix forming polymer from the matrix polymer solution, more preferably less than approximately 5 percent by weight of the matrix forming polymer and more preferably less than approximately 4 percent by weight of the matrix forming polymer. For example, the aerosol generating solution may comprise from approximately 1 percent by weight to approximately 6 percent by weight of the matrix forming polymer, or from approximately 1.5 percent by weight to approximately 5 percent by weight of the matrix forming polymer, or from approximately 2 percent by weight to approximately 4 percent by weight of the matrix forming polymer. Qfrncnn / zznz / E / YiAi For example, in preferred embodiments, the aerosol-generating solution may comprise between approximately 1 percent by weight and approximately 6 percent by weight of alginate, or between approximately 1.5 percent by weight and approximately 5 percent by weight of alginate, or between approximately 2 percent by weight and approximately 4 percent by weight of alginate. The aerosol-generating formulation components can be added individually and sequentially to the matrix polymer solution. In some cases, it may be desirable to control the order or sequence in which the components are added to the matrix polymer solution to control the viscosity of the aerosol-generating solution, as described in more detail below. Alternatively, two or more of the aerosol-generating formulation components may be combined before being added to the matrix polymer solution, wherein the combination of aerosol-generating formulation components is subsequently added to the matrix polymer solution. All components of the aerosol-generating formulation may be combined before being added to the matrix polymer solution, or only some of the components may be combined, with others being added to the matrix polymer solution individually and separately. In the latter case, the order of addition of the aerosol-generating formulation components may still be controlled as described herein. In a preferred embodiment of the invention, the aerosol-generating solution is formed by adding a liquid nicotine formulation to the matrix polymer solution, wherein the liquid nicotine formulation comprises nicotine and a polyhydric alcohol. Optionally, the liquid nicotine formulation further comprises an acid. The liquid nicotine formulation may be in the form of an electronic cigarette liquid formulation, for example. When a liquid nicotine formulation is added to the matrix polymer solution, an additional amount of nicotine, or acid, or both nicotine and acid, may subsequently be added to the matrix polymer solution to produce the aerosol-generating solution. In this case, the order of addition of the liquid nicotine formulation and the additional nicotine and acid may be controlled as described above.For example, when an additional amount of an acid is added to the matrix polymer solution, the acid is preferably added after the formulation of the liquid nicotine and any additional nicotine. Advantageously, this modality can provide a method for incorporating a tobacco extract into the matrix polymer solution so that it becomes incorporated into the generating element. Aerosol Qfrncnn / zznz / E / YiAi. In certain embodiments of the invention, it may be desirable to control the viscosity of the aerosol-generating solution. This may include controlling the viscosity of the matrix polymer solution as the aerosol-generating formulation components are added. For example, depending on the technique used to produce the discrete portion of the aerosol-generating solution in the later stage of the method, it may be preferable to provide the aerosol-generating solution with a viscosity within a specific range. Different techniques are likely to be facilitated by different viscosity solutions, and therefore, a suitable viscosity should be determined based on the technique used. In embodiments where the discrete portion of the aerosol-generating solution is produced by a gravity-drop process, as described below, the viscosity of the solution is preferably kept below approximately 5,000 mPa·s. This allows the aerosol-generating solution droplets to form under gravity and also allows the beads to achieve a stable shape in the crosslinking solution before crosslinking hardens the solution and fixes the final shape of the aerosol-generating element. For a gravity immersion method, the viscosity of the aerosol-generating solution is preferably between approximately 100 mPa·s and approximately 4,000 mPa·s, with greater preference between approximately 2,500 mPa·s and approximately 3,000 mPa·s. For the purposes of the present invention, the viscosity of the aerosol-generating solution can be measured using a rotational viscometer such as the Fungilab Viscolead ADV(L) with the following parameters: liquid volume 10 mL, temperature 25 degrees Celsius, and rotation speed 10–15 rpm. A suitable test method for viscosity measurement is described in ASTM D2983-19, “Standard Test Method for Low Temperature Viscosity of Automatic Transmission Fluids, Hydraulic Fluids, and Lubricants using a Rotational Viscometer.” In certain embodiments, controlling the viscosity of the aerosol-generating solution may preferably involve controlling the pH of the matrix polymer solution while adding the aerosol-generating formulation components. This is because, for some matrix polymer solutions, pH can affect viscosity. For example, in embodiments of the invention where the matrix-forming polymer comprises alginate, it is preferable to maintain the pFI of the solution above pH 4. This is intended to prevent any gelation of the alginate, which can occur at pH levels below pH 4, for example, due to hydrogen bonding. Qfrncnn / zznz / E / YiAi Gelation at a low pH would cause an unwanted increase in the viscosity of the aerosol generating solution, making it difficult to use certain techniques such as gravity drop, to form the aerosol generating element. In such embodiments where it is preferable to control the pH of the matrix polymer solution as the aerosol-generating formulation components are added, the aerosol-generating formulation components are preferably added sequentially to maintain the pH above a specific pH value. For example, when the matrix polymer comprises alginate, the aerosol-generating formulation components are preferably added sequentially to maintain the pH of the matrix polymer solution above pH 4, as discussed previously. When the aerosol-generating formulation components comprise an acid, the acid is preferably added last to maintain the pH of the matrix polymer solution at a relatively high level.Preferably, when the aerosol-generating formulation components comprise nicotine, the nicotine is added first to obtain a basic pH of the matrix polymer solution before the other aerosol-generating formulation is added. Alternatively or additionally, the viscosity of the aerosol-generating solution can be controlled by adjusting the solution's concentration. For example, the proportion of water in the aerosol-generating solution can be adjusted to regulate the viscosity. Preferably, the aerosol-generating solution comprises at least approximately 35 percent water by weight to maintain a suitable viscosity. Particularly preferably, the aerosol-generating solution comprises between approximately 35 percent and approximately 65 percent water by weight. According to a preferred embodiment of the present invention, a method is provided for producing an aerosol-generating element comprising the steps of: preparing a matrix polymer solution comprising a matrix-forming polymer in water; adding a plurality of aerosol-generating formulation components to the matrix polymer solution to form an aerosol-generating solution, wherein the aerosol-generating formulation components comprise a polyhydric alcohol, at least one alkaloid or cannabinoid, and an acid, and wherein the aerosol-generating formulation components are added sequentially to the matrix polymer solution such that the acid is added after the other aerosol-generating components; forming one or more drops of the aerosol-generating solution; and dropping one or more drops of the aerosol-generating solution into a solution of Qfrncnn / zznz / E / YiAi crosslinking of multivalent cations to crosslink the matrix-forming polymer, thereby forming an aerosol-generating element having a continuous polymer matrix and an aerosol-generating formulation comprising the aerosol-generating formulation components dispersed within the continuous polymer matrix; and removing the aerosol-generating element from the crosslinking solution and drying the aerosol-generating element. The method as defined forms an aerosol generating element having a continuous polymer matrix and an aerosol generating formulation comprising aerosol generating formulation components dispersed within the continuous polymer matrix. As defined above, the aerosol-generating solution comprises a polyhydric alcohol as one of the aerosol-generating formulation components. The polyhydric alcohol acts as the aerosol former of 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. Preferably, in an aerosol generating element produced according to the invention, the polyhydric alcohol is selected from the group consisting of glycerin, propylene glycol, and combinations thereof. In particularly preferred embodiments, the polyhydric alcohol is glycerin. The concentration of the polyhydric alcohol in the aerosol-generating solution is selected so that the level of polyhydric alcohol in the final aerosol-generating element is sufficiently high to produce an acceptable aerosol. Preferably, the aerosol-generating solution comprises at least approximately 20 percent by weight of a polyhydric alcohol, more preferably at least approximately 25 percent by weight of a polyhydric alcohol, more preferably at least approximately 30 percent by weight of a polyhydric alcohol, and more preferably at least approximately 35 percent by weight of a polyhydric alcohol. Preferably, the aerosol generating solution comprises less than approximately 60 percent by weight of a polyhydric alcohol, more preferably less than approximately 55 percent by weight of a polyhydric alcohol, more preferably less than approximately 50 percent by weight of a polyhydric alcohol, more preferably less than approximately 45 percent by weight of a polyhydric alcohol. For example, the aerosol-generating solution may comprise between approximately 20 percent by weight and approximately 60 percent by weight of a polyhydric alcohol, or between approximately 25 percent by weight and approximately 55 percent by weight of a polyhydric alcohol, or between approximately 30 percent by weight and approximately 50 percent by weight of a polyhydric alcohol. Qfrncnn / zznz / E / YiAi percent by weight of a polyhydric alcohol, or between approximately 35 percent by weight and approximately 45 percent by weight of a polyhydric alcohol. As defined above, the aerosol generating solution further comprises at least one alkaloid or cannabinoid compound as one of the aerosol generating formulation components. As used herein with reference to the invention, the term “alkaloid compound” describes any of a class of naturally occurring organic compounds containing one or more basic nitrogen atoms. Generally, an alkaloid contains at least one nitrogen atom in an amine-type structure. This or another nitrogen atom in the alkaloid compound molecule may be active as a base in acid-base reactions. Most alkaloid compounds have one or more of their nitrogen atoms as part of a cyclic system, such as a heterocyclic ring. In nature, alkaloid compounds are found primarily in plants and are especially 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 compounds” is used to describe both naturally occurring alkaloid compounds and synthetically manufactured alkaloid compounds. Preferably, the alkaloid is selected from the group consisting of: nicotine, anatabine and their combinations. As used herein with reference to the invention, the term “cannabinoid compound” describes any of a class of naturally occurring compounds found in parts of the cannabis plant—specifically, the species Cannabis sativa, Cannabis indica, and Cannabis ruderalis. Cannabinoid compounds are particularly concentrated in the flower heads of the female plants. Cannabinoid compounds found naturally in the cannabis plant include tetrahydrocannabinol (THC) and cannabidiol (CBD). In the context of the present invention, the term “cannabinoid compounds” is used to describe both naturally occurring and synthetically produced cannabinoid compounds. Preferably, the components of the aerosol-generating formulation comprise a cannabinoid compound selected from the group consisting of: tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), cannabinol (CBN), cannabigerol (CBG), cannabigerol monomethyl ether (CBGM), cannabivarin (CBV), Qfrncnn / zznz / E / YiAi cannabidivarin (CBDV), tetrahydrocannabivarin (THCV), cannabichromene (CBC), cannabicyclol (CBL), cannabichromevarin (CBCV), cannabigerovarin (CBGV), cannabielsoin (CBE), cannabicitran (TCC) and their combinations. In general, the level of the alkaloid or cannabinoid compound in the aerosol-generating solution can be selected so that the aerosol-generating element comprises up to approximately 10 percent by weight of an alkaloid or cannabinoid compound, or both. The content of the alkaloid or cannabinoid compound, or both, in the aerosol-generating element can be increased and adjusted to optimize the delivery of the alkaloid or cannabinoid compound, or both, to the consumer in aerosol form. Compared to existing aerosol-generating substrates based on the use of plant material, this can advantageously allow for higher contents of the alkaloid or cannabinoid compound, or both, per volume or weight of substrate, which can be convenient from a manufacturing perspective. Preferably, the aerosol-generating solution comprises at least approximately 0.5 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Therefore, the aerosol-generating solution preferably comprises at least approximately 0.5 percent by weight of an alkaloid compound, or at least 0.5 percent by weight of a cannabinoid compound, or at least approximately 0.5 percent by weight of a combination of an alkaloid compound and a cannabinoid compound. More preferably, the aerosol-generating solution comprises at least approximately 1 percent by weight of an alkaloid compound or a cannabinoid compound, or both; more preferably, at least approximately 2 percent by weight of an alkaloid compound or a cannabinoid compound, or both. The aerosol-generating solution preferably comprises less than approximately 10 percent by weight of an alkaloid compound or a cannabinoid compound, or both; more preferably, less than approximately 8 percent by weight of an alkaloid compound or a cannabinoid compound, or both; more preferably, less than approximately 6 percent by weight of an alkaloid compound or a cannabinoid compound, or both. For example, the aerosol-generating solution may comprise from approximately 0.5 percent by weight to approximately 10 percent by weight of an alkaloid compound or a cannabinoid compound or both, or from approximately 1 percent by weight to approximately 8 percent by weight of an alkaloid compound or a cannabinoid compound or both, or of Qfrncnn / zznz / E / YiAi approximately 2 percent by weight to approximately 6 percent by weight of an alkaloid compound or a cannabinoid compound or both. In some embodiments, the aerosol-generating formulation comprises one or more cannabinoids and an alkaloid compound comprising nicotine or anatabine. In some preferred embodiments, the aerosol-generating solution comprises nicotine. As used herein with reference to the invention, the term “nicotine” is used to describe nicotine, a nicotine base, or a nicotine salt. In embodiments in which the aerosol-generating formulation components comprise a nicotine base or a nicotine salt, the amounts of nicotine listed herein are the amount of freebase nicotine or the amount of protonated nicotine, respectively. The components of the aerosol-generating formulation may include natural nicotine or synthetic nicotine. The components of the aerosol-generating formulation may comprise one or more monoprotic nicotine salts. As used in the present description, with reference to the invention, the term “monoprotic nicotine salt” is used to describe a nicotine salt of a monoprotic acid. Preferably, the aerosol generating solution comprises at least approximately 0.5 percent by weight of nicotine. More preferably, the aerosol generating solution comprises at least approximately 1 percent by weight of nicotine. Even more preferably, the aerosol generating solution comprises at least approximately 2 percent by weight of nicotine. Additionally or alternatively, the aerosol generating solution preferably comprises less than approximately 10 percent by weight of nicotine. More preferably, the aerosol generating solution comprises less than approximately 8 percent by weight of nicotine. Even more preferably, the aerosol generating solution comprises less than approximately 6 percent by weight of nicotine. For example, the aerosol generating solution may comprise between approximately 0.5 percent by weight and approximately 10 percent by weight of nicotine, or between approximately 1 percent by weight and approximately 8 percent by weight of nicotine, or between approximately 2 percent by weight and approximately 6 percent by weight of nicotine. Preferably, the amount of nicotine in the aerosol generating solution is adjusted to provide an aerosol generating element comprising at least approximately 0.5 Qfrncnn / zznz / E / YiAi milligrams of nicotine, with greater preference at least approximately 1 milligram of nicotine, with greater preference at least approximately 1.5 milligrams of nicotine, with greater preference at least approximately 2 milligrams of nicotine, and with the highest preference at least approximately 2.5 milligrams of nicotine. The aerosol generating element can comprise up to approximately 6 milligrams Qfrncnn / zznz / E / YiAi of nicotine. Preferably, the amount of nicotine in the aerosol generating solution is therefore adjusted to provide an aerosol generating element comprising less than or equal to approximately milligrams of nicotine, more preferably less than or equal to approximately milligrams of nicotine, more preferably less than or equal to approximately milligrams of nicotine, more preferably less than or equal to approximately 3.5 milligrams of nicotine, and most preferably less than or equal to approximately 3 milligrams. In some preferred embodiments, the aerosol-generating formulation components comprise a cannabinoid compound. Preferably, the cannabinoid compound is selected from CBD and THC. Most preferably, the cannabinoid compound is CBD. The aerosol-generating solution may comprise up to approximately 10 percent by weight of CBD. Preferably, the aerosol-generating solution comprises at least approximately 0.5 percent by weight of CBD, more preferably at least approximately 1 percent by weight of CBD, and more preferably at least approximately 2 percent by weight of CBD. Preferably, the aerosol-generating solution comprises less than approximately 8 percent by weight of CBD, more preferably less than approximately 6 percent by weight of CBD. For example, the aerosol generating solution may comprise from approximately 0.5 percent by weight to approximately 10 percent by weight of CBD, with a greater preference for approximately 1 percent by weight to approximately 8 percent by weight of CBD, and still with a greater preference for approximately 2 percent by weight to approximately 6 percent by weight of CBD. As described above, in preferred embodiments of the invention, the aerosol-generating formulation components further comprise an acid. More preferably, the components of the aerosol-generating formulation comprise one or more organic acids. Even more preferably, the components of the aerosol-generating formulation comprise one or more carboxylic acids. Carboxylic acids suitable for use in the aerosol-generating formulation of aerosol-generating elements according to the present invention include, but are not limited to: 2-Ethylbutyric acid, acetic acid, adipic acid, benzoic acid, butyric acid, cinnamic acid, cycloheptanecarboxylic acid, fumaric acid, glycolic acid, hexanoic acid, lactic acid, levulinic acid, malic acid, myristic acid, octanoic acid, oxalic acid, propanoic acid, succinic acid, and sucanodeccyinic acid. In particularly preferred embodiments, the acid is lactic acid, levulinic acid, benzoic acid, fumaric acid, or acetic acid. Most preferably, the acid is lactic acid. The inclusion of an acid is especially preferred in embodiments where the aerosol-generating formulation components comprise nicotine, as it has been observed that the presence of an acid can stabilize species dissolved in the aerosol-generating solution, such as nicotine and other plant extracts. Without wishing to be limited to theory, it is understood that the acid can interact with the nicotine molecule, thereby stabilizing the protonated nicotine. Since protonated nicotine is non-volatile, it is more readily found in the liquid phase or as particles rather than in the vapor phase of an aerosol obtained by heating the aerosol-generating element.As such, nicotine loss can be minimized during the manufacture of the aerosol generating element, and a higher and better controlled nicotine delivery to the consumer can be advantageously ensured. Preferably, the aerosol-generating solution comprises at least approximately 0.5 percent by weight of the acid. More preferably, the aerosol-generating solution comprises at least approximately 1 percent by weight of the acid. Even more preferably, the aerosol-generating solution comprises at least approximately 2 percent by weight of the acid. Alternatively, the aerosol-generating solution preferably comprises less than approximately 10 percent by weight of the acid. More preferably, the aerosol-generating solution comprises less than approximately 8 percent by weight of the acid. Even more preferably, the aerosol-generating solution comprises less than approximately 6 percent by weight of the acid. For example, the aerosol generating solution may comprise from approximately 0.5 percent by weight to approximately 10 percent by weight of the acid, or from approximately 1 percent by weight to approximately 8 percent by weight of the acid, or from approximately 2 percent by weight to approximately 6 percent by weight of the acid. Preferably, when the aerosol generating solution comprises nicotine, the ratio The molar ratio of the acid to nicotine is between approximately 0.5:1 and approximately 2:1, with a greater preference between approximately 0.75:1 and approximately 1.5:1, with the maximum preference being approximately 1:1. When using a multivalent acid, such as a multivalent carboxylic acid, it may be preferable to provide a molar ratio of the acid groups to nicotine of between approximately 0.5:1 and approximately 2:1, with greater preference between approximately 0.75:1 and approximately 1.5:1, with the highest preference being approximately 1:1. The use of a multivalent acid thus allows a lower weight of the acid to be used while providing the same level of nicotine protonation. The aerosol-generating formulation components included in the aerosol-generating solution may optionally also include a flavoring. The flavoring may be in liquid or solid form. Optionally, the flavoring may be provided in a microencapsulated form where the flavoring is released upon heating. Preferably, the amount of flavoring in the aerosol-generating solution is adjusted to provide the desired flavoring level within the aerosol-generating element. Preferably, the aerosol-generating element has a flavoring level between approximately 0.05 percent by weight and approximately 1 percent by weight, with the most preference being between approximately 0.1 percent by weight and approximately 0.5 percent by weight. The flavorings suitable for use as components of an aerosol-generating formulation in the present invention include, but are not limited to: tobacco, menthol, mint 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 flavor. Optionally, the aerosol-generating solution may further comprise a plurality of susceptor particles. Susceptor particles are conductive particles capable of converting electromagnetic energy into heat. When placed in an alternating electromagnetic field, eddy currents and hysteresis losses are induced in the susceptor particles, causing them to heat up. Because the susceptor particles are in thermal contact or close thermal proximity to the aerosol-generating formulation of the aerosol-generating element, the aerosol-generating formulation is heated by the susceptor particles, resulting in the formation of an aerosol. The inclusion of susceptor particles in the aerosol-generating solution provides, by Qfrncnn / zznz / E / YiAi Therefore, an aerosol generating element that can be inductively heated. When the aerosol generating element is used in a device comprising an induction heater, changing the electromagnetic fields generated by one or more induction coils of an inductive heating device heats the susceptor particles, which then transfer the heat to the surrounding aerosol generating formulation of the aerosol generating element, mainly by heat conduction. The susceptor particles may be formed from any material that can be induction-heated to a temperature sufficient to generate an aerosol from the aerosol-generating formulation. Preferred susceptor particles comprise a metal or carbon. Preferred susceptor particles may comprise or consist of a ferromagnetic material, for example, a ferromagnetic alloy, ferritic iron, ferromagnetic steel, or stainless steel. Suitable susceptor particles may be, or comprise, aluminum. Preferred susceptor particles may be heated to a temperature above 250 degrees Celsius. Suitable susceptor particles may comprise a non-metallic core with a metallic layer disposed on the non-metallic core, for example, metallic tracks formed on the surface of a ceramic core.Susceptor particles may have an outer protective layer, for example, a ceramic or glass protective layer that encapsulates the susceptor particle. Susceptor particles may comprise a protective coating made of glass, ceramic, or an inert metal, formed on a core of susceptor material. The susceptor particles can have an average particle size of up to approximately 60 micrometers. For example, the susceptor particles can have an average particle size less than or equal to approximately 50 micrometers, or less than or equal to approximately 40 micrometers, or less than or equal to approximately 35 micrometers. Typically, in an aerosol generating solution for use in methods according to the present invention, the susceptor particles have an average particle size of at least approximately 1 micrometer, or at least approximately 2 micrometers, or at least approximately 5 micrometers, or at least approximately 10 micrometers. For example, the susceptor particles in the aerosol-generating solution may have an average particle size of approximately 1 micrometer to approximately 60 micrometers, or from approximately 2 millimeters to approximately 50 micrometers, or from approximately 5 micrometers to approximately 40 micrometers, or from approximately 10 micrometers to Qfrncnn / zznz / E / YiAi approximately 35 micrometers. Optionally, a solid filler may be added to the aerosol-generating solution. The inclusion of a solid filler can advantageously improve the physical properties of the resulting aerosol-generating element. A solid filler may also be used to control the properties of the aerosol-generating solution during the process of forming a discrete portion of the aerosol-generating solution. Suitable solid fillers will be known to those skilled in the art. For example, in certain embodiments of the present invention, the aerosol-generating solution further comprises plant material particles obtained by pulverizing, grinding, or comminuting plant material. By way of example, the aerosol-generating solution may further comprise tea particles, coffee particles, cannabis particles, clove particles, eucalyptus particles, star anise particles, or ginger particles. Alternatively or additionally, the aerosol-generating solution may further comprise tobacco particles obtained by pulverizing, grinding, or comminuting one or more sheets of tobacco leaves and tobacco leaf stems. The inventors of the present invention have discovered that by incorporating such plant particles into the aerosol-generating element, it is advantageously possible to produce an aerosol that provides a novel sensory experience.Such an aerosol provides unique flavors and can provide a greater level of mouth fullness. In embodiments where the aerosol-generating solution comprises plant particles, the amount of plant particles in the aerosol-generating solution is adjusted to provide the desired level of plant particles within the aerosol-generating element and the desired level of flavor within the generated aerosol. The aerosol-generating element may comprise up to approximately 40 percent by weight of plant particles. Preferably, the aerosol-generating element comprises less than or equal to approximately 35 percent by weight of plant particles. More preferably, the aerosol-generating element comprises less than or equal to approximately 30 percent by weight of plant particles. Still more preferably, the aerosol-generating element comprises less than or equal to approximately 25 percent by weight of plant particles. In some embodiments, the aerosol-generating element comprises at least approximately 1 percent by weight of plant particles. Preferably, the aerosol-generating element comprises at least approximately 2 percent by weight of plant particles. More preferably, the aerosol-generating element comprises at least Qfrncnn / zznz / E / YiAi approximately 5 percent by weight of plant particles. Even more preferably, the aerosol generating element comprises at least approximately 10 percent by weight of plant particles. For example, the aerosol-generating substrate may comprise between approximately 1 percent by weight and approximately 40 percent by weight of plant particles, with greater preference between approximately 2 percent by weight and approximately 35 percent by weight of plant particles, with greater preference between approximately 5 percent by weight and approximately 30 percent by weight of plant particles, and with maximum preference between approximately 10 percent by weight and approximately 25 percent by weight of plant particles. Providing a quantity of plant particles within this range ensures that sufficient flavor can be achieved from the plant particles, but without affecting the consistency of the aerosol generating solution so much that the processing of the aerosol generating solution to form the aerosol generating element is negatively affected. In embodiments where the aerosol-generating solution comprises plant particles, the plant particles may have an average particle size of up to approximately 60 micrometers. Preferably, the plant particles have an average particle size less than or equal to approximately 50 micrometers, with a higher preference less than or equal to approximately 40 micrometers, and with a higher preference less than or equal to approximately 35 micrometers. Typically, in an aerosol-generating solution for use in methods according to the present invention, the plant particles have an average particle size of at least approximately 1 micrometer, more preferably at least approximately 2 micrometers, more preferably at least approximately 5 micrometers, and most preferably at least approximately 10 micrometers. For example, the plant particles in the aerosol generating solution may have an average particle size of approximately 1 micrometer to approximately 60 micrometers, with a greater preference of approximately 2 millimeters to approximately 50 micrometers, with a greater preference of approximately 5 micrometers to approximately 40 micrometers, with the maximum preference of approximately 10 micrometers to approximately 35 micrometers. In the next stage of the method according to the invention, after the formation of the aerosol generating solution, a discrete portion of the generating solution is formed Qfrncnn / zznz / E / YiAi aerosol. The “discrete portion” of the solution corresponds to a specific volume of the solution, which is typically processed to provide an aerosol-generating element with a specific shape and size. The discrete portion of the aerosol-generating solution can be formed into a variety of shapes, depending on the desired shape of the aerosol-generating element. For example, the aerosol-generating solution can be shaped into spheres or cylinders to produce droplets, beads, or threads of the material. Alternatively, the aerosol-generating solution can be formed into a sheet, cut into strips or flakes, or drawn into an elongated filament or thread. In particularly preferred embodiments of the invention, the step of forming a discrete portion of the aerosol-generating solution comprises forming a droplet. Preferably, a droplet of the aerosol-generating solution is formed by a dripping process in which the aerosol-generating solution drips from an orifice or extrusion nozzle. The nozzle may optionally be connected to a pump. Particularly preferably, a droplet of the aerosol-generating solution is formed by a gravity-dripping process in which each droplet falls from the extrusion nozzle solely under gravity. Alternatively, the extrusion nozzle may be vibrated to aid in the formation and release of a droplet. In preferred embodiments of the invention, where a droplet is formed by a dripping process, the droplet diameter can be adjusted by adjusting the diameter of the extrusion nozzle or the viscosity of the aerosol-generating solution, or both. Preferably, an extrusion nozzle with an opening diameter between approximately 0.5 mm and approximately 6 mm is preferred, for producing an aerosol-generating element of a suitable size for use in an aerosol-generating article or system. Typically, in such embodiments, once released from the extrusion nozzle, the droplet falls under gravity into the crosslinking solution. Preferably, the droplet forms at a height of at least 0.1 meters above the crosslinking solution. This minimum droplet height is advantageous, for example, when a spherical droplet is desired, as it ensures that the droplet falls a sufficient distance to form a spherical shape. Preferably, the droplet forms at a height of less than 0.6 meters above the crosslinking solution to minimize any deformation of the droplet before it enters the crosslinking solution. In certain embodiments, a trickle-cutting process can be combined with a jet-breaking process, which breaks up the droplet or stream of aerosol-generating solution as it exits the nozzle to form smaller droplets. For example, a jet-breaking device, such as a rotating disc, can be provided below the extrusion nozzle to break up the solution. Qfrncnn / zznz / E / YiAi aerosol generator in droplets. This type of process is particularly suitable when aerosol generating elements with a relatively small diameter are desired. Alternatively, an electrostatic extrusion process can be used in which the flow of the aerosol-generating solution from the extrusion nozzle is separated by electrostatic charge. As with the jet cutting process, electrostatic extrusion can be particularly suitable for preparing aerosol-generating elements that have a relatively small diameter. As a further alternative, the aerosol-generating solution can be broken up by vibratory means provided in or near the nozzle. As discussed earlier, the desired viscosity of the aerosol-generating solution depends to some extent on the selected process for forming the discrete portion of the aerosol-generating solution. Suitable viscosity ranges have been indicated for a gravity dripping process. Jet cutting may be suitable for aerosol-generating solutions with a relatively high viscosity, for example, above 200 mPa·s. Conversely, electrostatic extrusion may be more suitable for aerosol-generating solutions with a low viscosity, for example, below 200 mPa·s. Once formed, the discrete portion of the aerosol-generating solution, preferably in the form of a droplet, is added to a multivalent cation crosslinking solution. This causes the matrix-forming polymer to crosslink, thus forming a continuous, solid polymer matrix, as described above. The crosslinking solution preferably comprises a solution of a multivalent metal salt, such as a metal chloride solution. Preferred multivalent cations include calcium, iron, aluminum, manganese, copper, zinc, or lanthanum. A particularly preferred salt is calcium chloride. In certain preferred embodiments of the invention, where the aerosol-generating solution comprises an acid, the calcium salt provided in the crosslinking solution may advantageously be a salt of the same acid. For example, in embodiments where the aerosol-generating solution comprises lactic acid, the crosslinking solution may advantageously comprise calcium lactate. When the aerosol generating solution contains nicotine, the acid in the aerosol generating solution forms a nicotine salt with the nicotine. Using a calcium salt corresponding to the acid in the aerosol generating solution therefore provides the same salt in the crosslinking solution as in the aerosol generating solution. This, in turn, advantageously limits the diffusion of nicotine salts out of the aerosol generating solution into the Qfrncnn / zznz / E / YiAi crosslinking solution during the crosslinking stage. Therefore, a higher concentration of the nicotine salt can be retained within the aerosol generating element. In addition, any potential waste of nicotine and acid during the production of the aerosol generating element can be reduced. Preferably, the crosslinking solution comprises between approximately 0.5 percent by weight and approximately 10 percent by weight of the multivalent metal salt in the crosslinking solution. Preferably, the crosslinking step is carried out without heating, for example, at room temperature (22 degrees Celsius). The duration for which the discrete portion of the aerosol-generating solution is left in the crosslinking solution can be selected depending on the desired degree of crosslinking in the aerosol-generating element. In certain preferred embodiments, the discrete portion of the aerosol-generating solution is left in the crosslinking solution for between approximately 10 minutes and approximately 30 minutes. Preferably, the crosslinking solution further comprises a polyhydric alcohol, which is the same as the polyhydric alcohol selected as the aerosol-generating formulation component. It has been found that the inclusion of the polyhydric alcohol in the crosslinking solution limits the diffusion of the polyhydric alcohol from the aerosol-generating solution into the crosslinking solution during the crosslinking step. This advantageously allows a higher concentration of the polyhydric alcohol to be retained within the aerosol-generating element than was previously possible. Furthermore, the reduced diffusion of the polyhydric alcohol into the crosslinking solution can advantageously help maintain the shape of the aerosol-generating element during the crosslinking process. Preferably, the crosslinking solution comprises between approximately 20 percent by weight and approximately 60 percent by weight of the polyhydric alcohol, more preferably between approximately 30 percent by weight and approximately 50 percent by weight of the polyhydric alcohol. As discussed previously, the polyhydric alcohol in the crosslinking solution is selected to match the polyhydric alcohol in the aerosol-generating solution. In preferred embodiments, the polyhydric alcohol is glycerin. In particularly preferred embodiments of the present invention, the concentration of the polyhydric alcohol within the crosslinking solution is adjusted depending on the concentration Qfrncnn / zznz / E / YiAi of that polyhydric alcohol within the aerosol-generating solution. In particular, it is desirable that the concentration of the polyhydric alcohol within the crosslinking solution be as close as possible to the concentration of the same polyhydric alcohol within the aerosol-generating solution. This has been found to optimize the beneficial effects of including the polyhydric alcohol in the crosslinking solution, as described above. Preferably, the concentration of the polyhydric alcohol in the crosslinking solution is within approximately 20 percent of the concentration of the same polyhydric alcohol in the aerosol-generating solution, more preferably within approximately 15 percent, and even more preferably within approximately 10 percent. In particularly preferred embodiments, the concentration of the polyhydric alcohol in the crosslinking solution is approximately equal to the concentration of the same polyhydric alcohol in the aerosol-generating solution. After crosslinking, the resulting aerosol-generating element is removed from the crosslinking solution, for example, using a sieve or similar apparatus. The aerosol-generating element is preferably rinsed to remove the crosslinking solution from its surface. It is then dried to reduce the water content to the desired level. Preferably, the drying of the aerosol generating element is carried out to reduce its water content to less than approximately 20 percent by weight, with more preferably less than approximately 15 percent by weight. This water level is preferred for the aerosol generating element in order to generate the aerosol efficiently after heating the element during use. Preferably, the drying of the aerosol generating element is carried out to reduce the water activity (aw) of the aerosol generating element to less than approximately 0.7, more preferably less than approximately 0.5. This advantageously reduces the likelihood of bacterial and fungal proliferation in the aerosol generating element. The term “water activity” is used herein with reference to the present invention to denote the ratio of the partial pressure of water vapor in equilibrium with an aerosol generating element to the saturation pressure of water vapor in equilibrium with pure water at the same temperature. As such, water activity is a dimensionless quantity between 0, corresponding to a completely anhydrous substance, and 1, corresponding to pure salt-free water. Methods for measuring the water activity of an aerosol generating element according to Qfrncnn / zznz / E / YiAi with the present invention are described in the 2017 publication of ISO 18787 (Food products - Determination of water activity). Preferably, the dew point measurement principle as described in ISO 18787 is used. The aerosol generating element can be dried using any suitable method, including, for example, a dryer in which the element is heated. The drying time and temperature can be adjusted depending on the equipment used and to achieve the desired moisture level. For example, the aerosol generating element can be dried at 25 degrees Celsius for 12 hours, or at 100 degrees Celsius for 3 hours. Alternatively, drying can be carried out under vacuum. The method according to the present invention may further comprise a step of coating the aerosol generating element to provide an external coating layer on the aerosol generating element. The coating step may take place before or after the drying step. An optional drying step may be incorporated after the coating step. Providing a coating layer over the aerosol generating element can be advantageous for many reasons. For example, a coating layer can significantly limit the permeation of oxygen or water vapor into the aerosol generating element, which can help extend its lifespan. Alternatively or additionally, a coating layer can help protect the structural integrity of the aerosol generating element or provide improved smoothness. In certain embodiments, a relatively fragile coating layer can be added to the aerosol generating element, designed to be broken by the consumer before use. This type of coating layer can thus provide the consumer with tactile and audible indications that the aerosol generating element has been activated.Alternatively or additionally, providing a coating layer over the aerosol generating element can 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. The appropriate types of coating material would be known to the expert. For example, a coating layer of a water-soluble film former, such as HPMC or shellac, can be applied to the aerosol-generating element. Such film formers will adhere strongly to the surface of the aerosol-generating element. In a further example, Qfrncnn / zznz / E / YiAi A coating layer of sodium alginate can be added, which will crosslink with any remaining calcium ions on the surface of the aerosol generating element to form a thin film of calcium alginate. A coating layer can be applied to the external surface of the aerosol-generating element using a variety of coating techniques. The expert would be familiar with the appropriate equipment and techniques. The method of the present invention has been described in relation to the production of a single aerosol generating element. However, it would be clear to someone skilled in the art that the present invention also encompasses methods for producing a plurality of aerosol generating elements. The method as described could easily be adapted by someone skilled in the art to produce a plurality of aerosol generating elements, for example, in a batch process in which a plurality of discrete portions of the aerosol generating solution are simultaneously produced and added to the crosslinking solution, or in a continuous process in which discrete portions of the aerosol generating solution are continuously produced and added to the crosslinking solution. The method of the present invention produces an aerosol generating element having a distinct structure. As defined above, the aerosol generating element comprises a continuous polymer matrix and an aerosol generating formulation dispersed within the continuous polymer matrix, wherein the aerosol generating formulation is trapped within the continuous polymer matrix. Without wishing to limit ourselves to theory, it is understood that, in an aerosol generating element according to the present invention, a three-dimensional polymer matrix structure is formed by crosslinking, and the aerosol generating formulation is retained within the continuous polymer matrix structure. This, in particular, contrasts with existing core / shell structures where the core contents are released upon rupture of the shell. The compounds that can be incorporated into the aerosol generating element and the preferred quantities of these compounds are described above in connection with the method of the present invention. Preferably, the aerosol-generating formulation dispersed within the solid continuous matrix structure represents at least approximately 70 percent by weight of the total weight of the aerosol-generating element, or even at least approximately 75 percent by weight of the total weight of the aerosol-generating element, or at least approximately 80 percent by weight of Qfrncnn / zznz / E / YiAi a total weight of the aerosol generating element. Most preferably, the aerosol-generating formulation dispersed within the solid continuous polymer matrix represents at least approximately 82 percent by weight of the total weight of the aerosol-generating element. Even more preferably, the aerosol-generating formulation dispersed within the continuous polymer matrix represents at least approximately 84 percent by weight of the total weight of the aerosol-generating element. In particularly preferred embodiments, the aerosol-generating formulation dispersed within the continuous polymer matrix represents at least approximately 86 percent by weight of the total weight of the aerosol-generating element. More preferably, the aerosol-generating formulation dispersed within the continuous polymer matrix represents at least approximately 88 percent by weight of the total weight of the aerosol-generating element. Still more preferably, the aerosol-generating formulation dispersed within the continuous polymer matrix represents at least approximately 90 percent by weight of the total weight of the aerosol-generating element. With maximum preference, the aerosol-generating formulation dispersed within the continuous polymer matrix represents at least approximately 92 percent by weight of a total weight of the aerosol-generating element, or at least approximately 93 percent by weight of a total weight of the aerosol-generating element, or at least approximately 94 percent by weight of a total weight of the aerosol-generating element, or at least approximately 95 percent by weight of a total weight of the aerosol-generating element. In aerosol generating elements where the aerosol-generating formulation represents a fraction of the total weight of the aerosol generating element within the ranges described above, it is advantageously possible to minimize the portion of heat supplied to the aerosol generating element during use that is consumed in raising the temperature of the encapsulation material. As such, a more efficient use of the heat supplied to the aerosol generating element becomes possible, so that the vast majority of this heat is effectively employed to release the aerosol formulation components from the continuous polymer matrix and generate an aerosol. As defined above, an aerosol-generating element according to the invention comprises a polyhydric alcohol as a component of the aerosol-generating formulation dispersed within the continuous polymer matrix. An aerosol-generating element according to the present invention preferably comprises at least approximately 30 Qfrncnn / zznz / E / YiAi percent by weight of polyhydric alcohol, more preferably at least approximately 40 percent by weight of polyhydric alcohol, more preferably at least approximately 50 percent by weight of polyhydric alcohol, more preferably at least approximately 60 percent by weight of polyhydric alcohol, more preferably at least approximately 70 percent by weight of polyhydric alcohol, based on the total weight of the aerosol generating element. Typically, in an aerosol generating element according to the invention, the polyhydric alcohol content in the aerosol generating formulation represents less than or equal to approximately 95 percent by weight based on the total weight of the aerosol generating element. As defined above, in an aerosol generating element according to the invention, the continuous polymer matrix is ​​formed by a crosslinked matrix-forming polymer. Preferably, the aerosol generating element comprises at least approximately 2 percent by weight of the matrix-forming polymer, more preferably at least approximately 2.5 percent by weight of the matrix-forming polymer, and more preferably at least approximately 3 percent by weight of the matrix-forming polymer. Preferably, the aerosol generating element comprises less than approximately 6 percent by weight of the matrix-forming polymer, more preferably less than approximately 5 percent by weight of the matrix-forming polymer, and more preferably less than approximately 4.5 percent by weight of the matrix-forming polymer.For example, the aerosol generating element may comprise from approximately 2 percent by weight to approximately 6 percent by weight of the matrix forming polymer, or from approximately 2.5 percent by weight to approximately 5 percent by weight of the matrix forming polymer, or from approximately 3 percent by weight to approximately 4.5 percent by weight of the matrix forming polymer. As defined above, in an aerosol-generating element according to the present invention, the aerosol-generating formulation dispersed within the continuous polymer matrix comprises at least one alkaloid or cannabinoid compound. In some embodiments, the aerosol-generating formulation dispersed within the continuous polymer matrix comprises both an alkaloid and a cannabinoid compound. In general, the aerosol-generating element may comprise up to approximately 10 percent by weight of an alkaloid compound or a cannabinoid compound, or both. In view of the applications of the aerosol-generating element of the invention as a substrate in an aerosol-generating article, this is advantageous since the alkaloid or cannabinoid compound content is reduced. The concentration of the cannabinoid compound or both in the element can be increased and adjusted with a view to optimize the delivery of the alkaloid compound or cannabinoid compound or both in aerosol form to a consumer. Compared to existing aerosol-generating substrates based on the use of plant material, this can advantageously allow for higher contents of the alkaloid compound or cannabinoid compound or both per volume of substrate (element or elements) or per weight of substrate (element or elements), which can be convenient from a manufacturing standpoint. Preferably, the content of at least one alkaloid or cannabinoid compound in the aerosol-generating formulation dispersed within the continuous polymer matrix represents at least 0.5 percent by weight of the total weight of the aerosol-generating element. Therefore, the aerosol-generating element preferably comprises at least approximately 0.5 percent by weight of an alkaloid compound, or at least 0.5 percent by weight of a cannabinoid compound, or at least approximately 0.5 percent by weight of a combination of an alkaloid compound and a cannabinoid compound. More preferably, the aerosol-generating element comprises at least approximately 1 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Even more preferably, the aerosol-generating element comprises at least approximately 2 percent by weight of an alkaloid compound or a cannabinoid compound, or both. The aerosol-generating element preferably comprises less than approximately 8 percent by weight of an alkaloid compound or a cannabinoid compound, or both. More preferably, the aerosol-generating element comprises less than approximately 6 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Still more preferably, the aerosol-generating element comprises less than approximately 5 percent by weight of an alkaloid compound or a cannabinoid compound, or both. Most preferably, the aerosol-generating element comprises less than approximately 4 percent by weight of an alkaloid compound or a cannabinoid compound, or both. In some embodiments, the aerosol-generating element comprises from approximately 0.5 percent by weight to approximately 10 percent by weight of an alkaloid compound or a cannabinoid compound or both, more preferably from approximately 1 percent by weight to approximately 10 percent by weight of an alkaloid compound or a cannabinoid compound or both, and even more preferably from approximately 2 percent by weight to approximately Qfrncnn / zznz / E / YiAi percent by weight of an alkaloid compound or a cannabinoid compound or both. As described above in relation to the method of the present invention, in some preferred embodiments, the aerosol generating element comprises nicotine. In general, the aerosol-generating element can comprise up to approximately 10 percent nicotine by weight. Given the applications of the aerosol-generating element of the invention as a substrate in an aerosol-generating article, this is advantageous because the nicotine content in the aerosol-generating element can be increased and adjusted to optimize the delivery of aerosolized nicotine to a consumer. Compared to existing aerosol-generating substrates based on the use of the tobacco plant, this can advantageously allow for higher nicotine contents per volume of substrate (element or elements) or per weight of substrate (element or elements), which can be convenient from a manufacturing standpoint. Preferably, the aerosol-generating element comprises at least approximately 0.5 percent by weight of nicotine. More preferably, the aerosol-generating element comprises at least approximately 1 percent by weight of nicotine. Even more preferably, the aerosol-generating element comprises at least approximately 2 percent by weight of nicotine. The aerosol-generating element preferably comprises less than or equal to approximately 8 percent by weight of nicotine. More preferably, the aerosol-generating element comprises less than or equal to approximately 6 percent by weight of nicotine. Still more preferably, the aerosol-generating element comprises less than or equal to approximately 5 percent by weight of nicotine. Most preferably, the aerosol-generating element comprises less than or equal to approximately 4 percent by weight of nicotine. In some forms, the aerosol generating element comprises from approximately 0.5 percent by weight to approximately 10 percent by weight of nicotine, with a greater preference for approximately 1 percent by weight to approximately 10 percent by weight of nicotine, and even more preferentially approximately 2 percent by weight to approximately 10 percent by weight of nicotine. Preferably, the aerosol-generating element comprises at least approximately 0.5 milligrams of nicotine. More preferably, the aerosol-generating element comprises at least approximately 1 milligram of nicotine. Even more preferably, the element The aerosol generator Qfrncnn / zznz / E / YiAi comprises at least approximately 1.5 milligrams of nicotine. In particularly preferred embodiments, the aerosol generating element comprises at least approximately 2 milligrams of nicotine, and most preferably at least approximately 2.5 milligrams of nicotine. The aerosol-generating element may comprise up to approximately 6 milligrams of nicotine. Preferably, the aerosol-generating element comprises less than or equal to approximately 5 milligrams of nicotine. More preferably, the aerosol-generating element comprises less than or equal to approximately 4.5 milligrams of nicotine. Still more preferably, the aerosol-generating element comprises less than or equal to approximately 4 milligrams of nicotine. In particularly preferred embodiments, the aerosol-generating element comprises less than or equal to approximately 3.5 milligrams of nicotine, and most preferably less than or equal to approximately 3 milligrams of nicotine. In some preferred embodiments, the aerosol-generating formulation dispersed within the continuous polymer matrix 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. The aerosol-generating element may comprise up to approximately 10 percent by weight of CBD. Preferably, the aerosol-generating element comprises at least approximately 0.5 percent by weight of CBD. More preferably, the aerosol-generating element comprises at least approximately 1 percent by weight of CBD. Even more preferably, the aerosol-generating element comprises at least approximately 2 percent by weight of CBD. The aerosol-generating element preferably comprises less than or equal to approximately 6 percent by weight of CBD. More preferably, the aerosol-generating element comprises less than or equal to approximately 5 percent by weight of CBD. Even more preferably, the aerosol-generating element comprises less than or equal to approximately 4 percent by weight of CBD. In some formulations, the aerosol generating element comprises from approximately 0.5 percent by weight to approximately 10 percent by weight of CBD, with a greater preference for approximately 1 percent by weight to approximately 10 percent by weight of CBD, and still with a greater preference for approximately 2 percent by weight to approximately 10 percent by weight of CBD. Qfrncnn / zznz / E / YiAi An aerosol generating element according to the present invention may be an essentially tobacco-free aerosol generating element. As used herein with reference to the invention, the term essentially 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 approximately 0.75 percent by weight, less than approximately 0.5 percent by weight, or less than approximately 0.25 percent by weight. The aerosol generating element can be a tobacco-free aerosol generating element. As used herein with reference to the invention, the term tobacco-free aerosol generating element describes an aerosol generating element having a tobacco content of 0 percent by weight. As described above, in some embodiments, the aerosol-generating formulation dispersed within the continuous polymer matrix further comprises an acid. The aerosol generating element may comprise up to approximately 10 percent by weight of an acid. Preferably, the aerosol-generating element comprises at least approximately 0.5 percent by weight of an acid. More preferably, the aerosol-generating element comprises at least approximately 1 percent by weight of an acid. Even more preferably, the aerosol-generating element comprises at least approximately 2 percent by weight of an acid. The aerosol-generating element preferably comprises less than or equal to approximately 8 percent by weight of an acid. More preferably, the aerosol-generating element comprises less than or equal to approximately 6 percent by weight of an acid. Even more preferably, the aerosol-generating element comprises less than or equal to approximately 5 percent by weight of an acid. More preferably, the aerosol-generating element comprises less than or equal to approximately 4 percent by weight of an acid. In some embodiments, the aerosol generating element comprises from approximately 0.5 percent by weight to approximately 10 percent by weight of an acid, more preferably from approximately 1 percent by weight to approximately 10 percent by weight of an acid, still more preferably from approximately 2 percent by weight to approximately 10 percent by weight of an acid. Qfrncnn / zznz / E / YiAi An aerosol generating element according to the present invention preferably comprises less than or equal to approximately 25 percent by weight of water. More preferably, the aerosol-generating element comprises less than or equal to approximately 20 percent by weight of water. Even more preferably, the aerosol-generating element comprises less than or equal to approximately 15 percent of water. An aerosol generating element according to the present invention preferably comprises at least approximately 2.5 percent by weight of water. More preferably, the aerosol generating element according to the present invention preferably comprises at least approximately 5 percent by weight of water. Even more preferably, the aerosol generating element according to the present invention preferably comprises at least approximately 7.5 percent by weight of water. Most preferably, the aerosol generating element according to the present invention preferably comprises at least approximately 10 percent by weight of water. In general, the presence of some water has been observed to contribute to the aerosol-generating element's stability. At the same time, a residual water content of 25 percent by weight or less is desirable, as it yields an essentially non-sticky aerosol-generating element. Furthermore, heating an aerosol-generating element with a lower water content can provide the consumer with an aerosol more concentrated in the polyhydric alcohol and the alkaloid or cannabinoid compound, such as nicotine. An aerosol generating element according to the invention may have an equivalent diameter of at least approximately 0.5 millimeters. The term “equivalent diameter of an aerosol generating element” is used herein to denote the diameter of the sphere that has 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 egg or ellipsoid, is preferred. For an aerosol generating element that has a spherical shape and a circular cross-section, the equivalent diameter is the diameter of the cross-section of the aerosol generating element. Preferably, the aerosol-generating element has an equivalent diameter of at least approximately 1 millimeter. More preferably, the aerosol-generating element has an equivalent diameter of at least approximately 2 millimeters. Even more preferably, the aerosol-generating element has an equivalent diameter of at least approximately 3 millimeters. Qfrncnn / zznz / E / YiAi millimeters. An aerosol generating element according to the invention preferably has an equivalent diameter of less than or equal to approximately 8 millimeters. More preferably, the aerosol generating element has an equivalent diameter of less than or equal to approximately 6 millimeters. Even more preferably, the aerosol generating element has an equivalent diameter of less than or equal to approximately 5 millimeters. In some embodiments, the aerosol generating element has an equivalent diameter of approximately 0.5 millimeters to approximately 8 millimeters, preferably from approximately 1 millimeter to approximately 8 millimeters, with greater preference from approximately 2 millimeters to approximately 8 millimeters, and even more preferentially from approximately 3 millimeters to approximately 8 millimeters. In particularly preferred embodiments, the aerosol generating element has an equivalent diameter of approximately 4 millimeters or approximately 4.5 millimeters. The aerosol generating elements according to the present invention can have an ovality of up to approximately 35 percent. The term “ovality” as used herein with reference to the present invention denotes the degree of deviation from a perfect circle. Ovality is expressed as a percentage, and the mathematical definition is given below. Circular shape a - b Oval shape Qfrncnn / zznz / E / YiAir2 (a — b) ovality (%) = ----x 100% a + b To determine the ovality of an object, such as an aerosol-generating element, the object can be viewed along a direction essentially perpendicular to a cross-section of the aerosol-generating element. For example, the aerosol-generating element can be placed on a transparent stage so that an image of the aerosol-generating element is recorded by a suitable imaging device located below the stage. Dimension “a” is considered the largest external diameter of the image of the aerosol-generating element, and dimension “6” is considered the smallest external diameter of the image of the aerosol-generating element. The process is repeated for a total of ten aerosol-generating elements that have the same composition and are prepared by the same process and under the same operating conditions.The numerical average of the ten ovality measurements is recorded as the ovality for that aerosol-generating element. Preferably, an aerosol generating element according to the invention has an ovality of less than or equal to approximately 30 percent. More preferably, an aerosol generating element according to the invention has an ovality of less than or equal to approximately 25 percent. Even more preferably, an aerosol generating element according to the invention has an ovality of less than or equal to approximately 20 percent. An aerosol generating element according to the invention typically has an ovality of at least approximately 1 percent. Preferably, the aerosol generating element has an ovality of at least 2 percent. More preferably, the aerosol generating element has an ovality of at least 3 percent. Even more preferably, the aerosol generating element has an ovality of at least 4 percent. In some modalities, the aerosol generating element has an ovality of approximately 1 percent to approximately 30 percent, with greater preference of approximately 2 percent to approximately 30 percent, with greater preference of approximately 3 percent to approximately 30 percent, still with greater preference of approximately 4 percent to approximately 30 percent. An aerosol generating article according to the present invention may have an exposed surface area to volume ratio of up to 25 cm1. The expression “surface area exposed to volume ratio”, as used in the present description with reference to the present invention, denotes the ratio between the total external surface area of ​​the aerosol generating element, which is exposed and available for heat and mass exchange, and the total volume of the aerosol generating element. Since the aerosol generating elements according to the invention have low ovality and can be approximated as spherical objects, the volume of an aerosol generating element according to the invention can be expressed by the formula 471 (ñeq) volume = -------3 The exposed surface area of ​​an aerosol generating element according to the invention Qfrncnn / zznz / E / YiAi can be estimated using the formula exposed surface area = 4π (Req)2 The Req dimension denotes an equivalent radius of the aerosol generating element. Preferably, the aerosol-generating article has an exposed surface area to volume ratio of at least approximately 0.083 cm². More preferably, the aerosol-generating article has an exposed surface area to volume ratio of at least approximately 0.166 cm². Even more preferably, the aerosol-generating article has an exposed surface area to volume ratio of at least approximately 0.249 cm². The aerosol-generating article preferably has an exposed surface area to volume ratio less than or equal to approximately 24 cm². More preferably, the aerosol-generating article has an exposed surface area to volume ratio less than or equal to approximately 20 cm². Even more preferably, the aerosol-generating article has an exposed surface area to volume ratio less than or equal to approximately 16 cm². In some embodiments, the aerosol generating article has an exposed surface area to volume ratio of approximately 0.083 cm1 to approximately 24 cm1, with greater preference of approximately 0.166 cm1 to approximately 24 cm1, with even greater preference of approximately 0.249 cm1 to approximately 24 cm1. In some embodiments, the aerosol generating elements according to the present invention can be coated, as described above in relation to the method of the present invention. Aerosol-generating elements as described above can be used as an aerosol-generating substrate for aerosol-generating articles of the type where the substrate is heated to release an inhalable aerosol - as opposed to articles where a substrate is burned to produce smoke. Since the aerosol generating elements according to the invention are easy to manufacture and predetermined, discrete quantities of an aerosol generating formulation can therefore be provided in encapsulated form, and because the composition of the aerosol generating formulation, especially with regard to the polyhydric alcohol content and the alkaloid or cannabinoid compound, can be precisely adjusted and controlled, the aerosol generating elements according to the invention are versatile and can be used as substrates in a number of arrangements. Qfrncnn / zznz / E / YiAi By way of 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 external surface of the aerosol-generating elements is exposed within the longitudinal airflow channel defined by the cavity. Upon heating, an aerosol may be generated from the aerosol-generating elements, which is therefore released into the airflow channel and can be inhaled through the tubular element into the consumer's mouth. Therefore, aerosol generating elements as described above can be used in an aerosol generating system comprising one or more aerosol generating elements or an aerosol generating article 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 one or more aerosol generating elements or the article such that one or more aerosol generating elements are heated in the heating chamber by the heating element. Upon heating, the aerosol-generating elements according to the present invention release an aerosol containing the aerosol-generating formulation components, which include, in particular, the polyhydric alcohol and the alkaloid or cannabinoid compound. When an aerosol-generating element according to the present invention is heated to a temperature in the range of approximately 150 degrees Celsius to approximately 350 degrees Celsius, it has been found that the aerosol-generating element loses weight without undergoing significant volume contraction.Furthermore, it has been found that when an aerosol generating element according to the present invention is heated to a temperature in the range of approximately 150 degrees Celsius to approximately 350 degrees Celsius, and heated until no further weight loss is detected, a residual weight of the aerosol generating element is typically less than 120 percent of a weight of the continuous polymer matrix components, preferably less than 115 percent of a weight of the continuous polymer matrix components, more preferably less than 115 percent of a weight of the continuous polymer matrix components, and even more preferably less than 105 percent of a weight of the continuous polymer matrix components. With the highest preference, when an aerosol generating element according to the present invention is heated to a temperature in the range of approximately 150 degrees Celsius to approximately 350 degrees Celsius, and heat is supplied until no further weight loss is detected, a residual weight of the aerosol generating element corresponds Qfrncnn / zznz / E / YiAi essentially to the total weight of the components of the continuous polymer matrix. One embodiment of the invention will now be described further, by way of example only. Example An aerosol-generating solution is formed from a mixture of the following components: Qfrncnn / zznz / E / YiAi Component % by weight Glycerin 43.6 Sodium alginate 2.1 Nicotine 1.2 Levulinic acid 1.4 Water 51.7 In an initial step, sodium alginate is added to water to form a matrix polymer solution. Nicotine is then added, followed by glycerin, and finally, levulinic acid. The resulting aerosol-generating solution is extruded through a 5-millimeter nozzle to form a plurality of droplets, which then fall from a height of 30 centimeters into a crosslinking solution having the following composition at room temperature: Component % by weight Glycerin 42.9 Water 52.1 Calcium chloride 5.0 The droplets are left in the crosslinking solution for 25 minutes before being removed and dried at 25°C for 12 hours in a tray dryer. The resulting dried aerosol-generating elements are in the form of solid, spherical beads approximately 4.6 mm in diameter. Each bead weighs approximately 65 mg, has an aqueous activity of 0.4, and the following composition: Component % by weight Glycerin 76.8 Alginate 3.8 Nicotine 2.4 Levulinic acid 2.1 Water 14.4 Calcium chloride 0.5 Qfrncnn / zznz / E / γΐΛΐ

Claims

1. A method for producing an aerosol generating element for an aerosol generating article or system, the method comprising the steps of: preparing a matrix polymer solution comprising a matrix-forming polymer in water; adding a plurality of aerosol generating formulation components to the matrix polymer solution to form an aerosol generating solution, wherein the aerosol generating formulation components comprise a polyhydric alcohol and at least one alkaloid or cannabinoid and wherein the aerosol generating solution comprises at least one 0.5 percent by weight of at least one alkaloid or cannabinoid; form a discrete portion of the aerosol-generating solution; add the discrete portion of the aerosol-generating solution to a multivalent cation crosslinking solution to crosslink the matrix-forming polymer; and remove the aerosol-generating element from the crosslinking solution and dry the aerosol-generating element.

2. A method according to claim 1 wherein the aerosol-generating formulation components further comprise an acid.

3. A method according to claim 1 or 2 wherein the step of forming a discrete portion of the aerosol generating solution comprises forming a droplet of the aerosol generating solution and wherein the droplet falls into the crosslinking solution from a height of at least 10 cm.

4. A method according to any of the preceding claims, wherein the viscosity of the aerosol generating solution is at least 5,000 mPa.s.

5. A method according to any of the preceding claims, wherein the aerosol-generating formulation components are added sequentially to the matrix polymer solution.

6. A method according to any of the preceding claims, wherein the aerosol-generating solution Qfrncnn / zznz / E / YiAi comprises at least 20 percent by weight of the polyhydric alcohol.

7. A method according to any of the preceding claims, wherein the polyhydric alcohol is glycerin, propylene glycol, or a combination of glycerin and propylene glycol.

8. A method according to any of the preceding claims, wherein the aerosol generating solution comprises at least 0.5 percent by weight of nicotine.

9. A method according to any of the preceding claims, wherein the matrix-forming polymer comprises alginate and wherein the matrix polymer solution comprises at least 45 percent by weight of water.

10. A method according to any of the preceding claims, wherein the crosslinking solution comprises at least 20 percent by weight of a polyhydric alcohol, wherein the polyhydric alcohol in the crosslinking solution is the same as the polyhydric alcohol in the aerosol generating solution.

11. A method according to claim 10 wherein the concentration of the polyhydric alcohol in the crosslinking solution is within 20 percent of the concentration of the polyhydric alcohol within the aerosol generating solution.

12. A method according to any of the preceding claims, wherein during the drying stage, the water content of the aerosol generating element is reduced to less than 20 percent by weight.

13. A method according to any of the preceding claims, wherein after drying the aerosol generating element has a polyhydric alcohol content of at least 60 percent by weight.

14. An aerosol generating element produced by the method of any preceding claim, the aerosol generating element comprising at least 60 percent by weight of polyhydric alcohol, at least 0.5 percent by weight of nicotine and at least 0.5 percent by weight of acid.