Manufacturing method for non-aqueous composition

Abstract

A method of preparing a non-aqueous composition comprising the sequential steps of i) heating an organic polyol and a structuring agent in a mixture to a temperature of 69 DEG C or higher, ii) adding an abrasive and other non-flavoring ingredients to the mixture; iii) rapidly cooling the resulting mixture at a cooling rate of 5 DEG C / min or higher to form a paste or gel.

Description

Technical Field

[0001] The present invention relates to a method for producing a non-aqueous composition. Background Art

[0002] Non-aqueous paste compositions prove difficult to manufacture due to the difficulty in controlling the rheology of the paste. The stability of non-aqueous pastes may also be problematic.

[0003] The problem with non-aqueous formulations such as those disclosed in WO96 / 03108 is that their rheological behavior is not like that of typical aqueous dentifrices. This problem is observed both during manufacturing and during consumer use. This leads to manufacturing difficulties and reduced acceptance among consumers. The viscosity profile and flow properties are key factors controlling the processing ease, product performance and consumer perception of dentifrices.

[0004] EP2089040 describes an oral care composition which remineralizes eroded teeth and / or whitens teeth. The composition may be a two-phase composition comprising a calcium ion source, a phosphate ion source. For such a system, it is preferred that the water content in the composition is low.

[0005] There remains a need for non-aqueous pastes, particularly oral care toothpastes, that have excellent rheological properties such as viscosity, that are stable, and that preferably include high levels of materials that can remineralize tooth enamel. Summary of the invention

[0006] The present invention provides a method for making a non-aqueous composition comprising the following sequential steps:

[0007] i) heating the organic polyol and the structuring agent in the mixture to a temperature of 69° C. or higher,

[0008] ii) adding grinding agent and other non-flavour ingredients to the mixture,

[0009] iii) rapidly cooling the resulting mixture at a cooling rate of 5° C. / min or more to form a paste or gel. DETAILED DESCRIPTION OF THE INVENTION

[0011] Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or reaction conditions, physical properties of materials and / or use may be understood as being optionally modified by the word "about".

[0012] Unless otherwise indicated, all amounts are by weight of the composition.

[0013] It should be noted that in specifying any range of numerical values, any higher numerical value can be correlated with any particular lower numerical value.

[0014] Where features are disclosed with respect to a particular aspect of the invention (eg, the compositions of the invention), such disclosure is also considered to apply mutatis mutandis to any other aspect of the invention (eg, the methods of the invention).

[0015] Any ingredients referred to as natural or of natural origin in this application are of European origin.

[0016] The compositions of the present invention are preferably used for cleaning oral surfaces and are referred to as oral care compositions. Thus, preferred product forms of the compositions of the present invention are those suitable for brushing and / or rinsing oral surfaces.

[0017] The compositions of the present invention are most preferably in the form of a dentifrice. The term "dentifrice" refers to an oral composition used to clean the surfaces of the oral cavity. Such compositions are not intended to be swallowed for the purpose of systemic administration of the therapeutic agent, but are applied to the oral cavity, used to treat the oral cavity, and then expectorated. Typically such compositions are used in conjunction with a cleaning implement such as a toothbrush, typically by applying it to the bristles of the toothbrush and then brushing the accessible surfaces of the oral cavity.

[0018] Preferably, the dentifrice / toothpaste is in an extrudable semi-solid form such as a paste, paste or gel (or mixtures thereof).

[0019] Compositions according to the invention (eg dentifrices / toothpastes) will typically contain additional ingredients in addition to those listed above to enhance performance and / or consumer acceptability.

[0020] The rheological behavior of the compositions prepared by this process can be well controlled to achieve the desired sensory effects.Another particular advantage of the compositions of the invention is their storage stability.

[0021] The compositions of the present invention are non-aqueous. "Non-aqueous" generally means that water is not intentionally added to the composition in any significant amount. However, the term "non-aqueous" does not mean that small amounts of water cannot be present, for example due to its association with hygroscopic raw materials. Therefore, for the purposes of the present invention, the term "non-aqueous" generally means that water is present in an amount of no more than about 5 weight percent, more preferably no more than about 3 weight percent, based on the total weight of the composition.

[0022] Polyols

[0023] Compositions of the present invention comprise organic polyols. Polyols for use in the present invention include glycerol and / or other polyols that may be present, such as xylitol, mannitol, lactitol, maltitol, erythritol and hydrogenated partially hydrolyzed polysaccharides. Mixtures of any of the above materials may also be used.

[0024] The content of organic polyol depends on the specific type selected, but is generally about 20-90 weight % based on the gross weight of composition.Based on the gross weight of composition, the amount of organic polyol is suitably in the scope of 35 to 75 weight %, more preferably 45 to 70 weight % organic polyol.In the context of the present invention, term " organic polyol " refers to that composition is not oil-based or water-based, but organic polyol (as defined above) is the main component in composition." main component " refers to that organic polyol (as defined above) all constitutes the higher part of composition weight when together than any other compound.Ideally, composition of the present invention is based on glycerol (that is, glycerol all constitutes the higher part of composition weight than any other compound), and contains 45 to 70 weight % glycerol based on gross weight of composition.

[0025] Structuring agent

[0026] The composition of the present invention comprises a structuring agent. A preferred structuring agent is one or more crystals of solid polyethylene glycol having a melting point of 25°C or higher. Preferably, the melting point is 35-65°C, more preferably 55-60°C.

[0027] Polyethylene glycol has the general formula H(OCH2CH2) n OH, wherein n is the number of repeating oxyethylene units. Commercially available polyethylene glycols are generally not homogeneous compounds, but consist of a distribution of similar polymer members of a homologous polyethylene glycol series, defined by an average value of n and a molecular weight. The melting point generally increases with increasing average values ​​of n and molecular weight. Suitable solid polyethylene glycols have an average value of n of about 20-220, preferably about 40-150, more preferably about 32-90, and most preferably about 60-75 in the above general formula. The average molecular weight is suitably about 950-11,250, preferably about 1800-6600, more preferably about 1400-4400, and most preferably about 2700-3700 g / mol. Suitable commercially available materials include, for example 3000 (from Clariant). Mixtures of any of the above materials may also be used.

[0028] The amount of solid polyethylene glycol (as defined above) in the composition of the invention is suitably 0.1-5%, preferably 0.5-3%, more preferably 1-2.5%, based on the total weight of the composition.

[0029] Another structurant includes xanthan gum. Xanthan gum is a fermentation product prepared by the action of bacteria of the genus Xanthomonas on carbohydrates. Four species of Xanthomonas, namely X. campestris, X. phaseoli, X. malvocearum and X. carotae, are reported in the literature as being the most effective producers of xanthan gum.

[0030] Xanthan gum can generally be characterized as an anionic heteropolysaccharide having a main structure consisting of repeating pentasaccharide units formed by two glucose units, two mannose units and glucuronic acid units. These repeating pentasaccharide units give xanthan gum its characteristic backbone, which consists of (1→4) β-D-glucopyranosyl units substituted by charged trisaccharide side chains at C-3 on every other glucose residue. The trisaccharide side chains consist of D-glucuronic acid units between 2D-mannose units. Slightly less than half (about 40%) of the terminal D-mannose residues contain pyruvic acid residues connected to positions four and six by keto groups, and the D-mannose connected to the main chain contains mainly acetyl groups at positions O-6. Some side chains may be missing. Acetate and pyruvate content is variable on the side chains and depends on the bacterial strain and fermentation conditions used to produce the gum.

[0031] Xanthan gum generally has a molecular weight of 1 to 50 million. Its viscosity is generally 850 to 1,700 mPa.s (when measured at 25°C using a 1% solution of the gum in 1% KCl on a Brookfield LV type viscometer, using a No. 3 spindle at 60 rpm).

[0032] Xanthan gum is available from several commercial suppliers such as RT Vanderbilt Company and CP Kelco. An example of a suitable xanthan gum is and

[0033] The amount of xanthan gum in the composition of the present invention is preferably 0.05-1.5 wt%, more preferably 0.1-0.9 wt% (based on the total weight of the oral care composition).

[0034] Another embodiment of the present invention includes carrageenan as a structuring agent. Preferably, the carrageenan is present in a weight ratio of iota carrageenan to kappa carrageenan of 1:2 to 2:1.

[0035] The carrageenan present in the composition of the invention preferably consists of a total content of 33% to 66% by weight of iota carrageenan and 33% to 66% by weight of kappa carrageenan.

[0036] The total content of carrageenan is 0.05-1 wt %, more preferably 0.08-0.5 wt %, most preferably 0.05-0.25 wt % of the total composition.

[0037] Mixtures of structurants may be used.

[0038] Remineralizing Agents

[0039] In one embodiment, a preferred class of oral care actives for inclusion in the compositions of the present invention comprises agents for tooth remineralization.In the context of the present invention, the term "remineralization" refers to the in situ generation of hydroxyapatite on teeth.

[0040] A specific example of a suitable agent for tooth remineralization is a mixture of a calcium source and a phosphate source which, when delivered to the teeth, results in the in situ formation of hydroxyapatite on the teeth.

[0041] Illustrative examples of the types of calcium sources that can be used herein (hereinafter referred to as "remineralizing calcium sources") include, for example, calcium phosphate, calcium gluconate, calcium oxide, calcium lactate, calcium glycerophosphate, calcium carbonate, calcium hydroxide, calcium sulfate, calcium carboxymethylcellulose, calcium alginate, calcium salts of citric acid, calcium silicate, and mixtures thereof. Preferably, the remineralizing calcium source is calcium silicate.

[0042] The amount of remineralizing calcium source (eg calcium silicate) in the composition of the present invention is typically 1-30%, preferably 5-20%, based on the total weight of the oral care composition.

[0043] Illustrative examples of types of phosphate sources that can be used herein (hereinafter referred to as "remineralized phosphate sources") include, for example, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium pyrophosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, potassium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, and mixtures thereof. Preferably, the remineralized phosphate source is a mixture of trisodium phosphate and sodium dihydrogen phosphate.

[0044] The amount of remineralizing phosphate source (eg, trisodium phosphate and monosodium phosphate) in the composition of the present invention is typically 2-15%, preferably 4-10% of the total amount of remineralizing phosphate source, based on the total weight of the oral care composition.

[0045] Mixtures of any of the above materials may also be used.

[0046] Additional Ingredients

[0047] Compositions according to the invention, in particular toothpastes, preferably contain particulate abrasive materials, such as silica, alumina, calcium carbonate, dicalcium phosphate, calcium pyrophosphate, hydroxyapatite, trimetaphosphate, insoluble hexametaphosphate and the like, including agglomerated particulate abrasive materials, typically in an amount of 3% to 60% by weight of the oral care composition.

[0048] Preferably, the composition, in particular the toothpaste, comprises a silica-based abrasive. The preferred abrasive silica for use in the present invention is a silica with a low refractive index. It can be used as the only abrasive silica, or in combination with low levels of other abrasive silicas, such as those according to EP236070. The low refractive index silica used as an abrasive in the present invention is preferably a silica with an apparent refractive index (RI) in the range of 1.41-1.47, preferably in the range of 1.435-1.445, preferably with a weight average particle size of 5-15 mm, 10-100 m 2 / g BET (nitrogen) surface area, and about 70-150 cm 3 The oil absorption of 1 / 100 g is preferably 0.1%, but ground silicas with a lower apparent refractive index may also be used. Typical examples of suitable low refractive index ground silicas (e.g. with an RI between 1.435 and 1.445) are Tixosil 63 and 73 from Rhone Poulenc; Sident 10 from Degussa; Zeodent 113 from Zeofinn; Zeodent 124 from Evonik, Sorbosil AC 77 from PQ Corporation (with an RI of about 1.440). The amount of these silicas in the composition is typically 5-60% by weight, typically 5-20% by weight.

[0049] The composition, particularly if it is a toothpaste, preferably contains an inorganic or natural or synthetic thickener or gelling agent in a proportion of about 0.10 to about 15% by weight, depending on the material selected. These proportions of thickener in the dentifrice composition of the present invention form an extrudable, shape-retaining product that can be extruded from a tube onto a toothbrush and does not fall between the bristles of the toothbrush, but can substantially retain its shape thereon. Suitable thickeners or gelling agents that can be used in the practice of the present invention include inorganic thickening silica, such as amorphous silica available from Huber Corporation under the trade name Zeodent 165, Irish moss, iota-carrageenan, tragacanth gum, and polyvinylpyrrolidone.

[0050] The composition according to the invention preferably comprises a polymeric deposition aid. Preferably, the composition comprises an anhydride polymer, particularly preferably a copolymer of maleic anhydride and methyl vinyl ether, wherein the anhydride portion may be in a partially or completely hydrolyzed or alcoholyzed form. Preferred copolymers include Gantrez(R) polymers, for example:

[0051] Gantrez S-95: molecular weight 216,000; free acid form;

[0052] Gantrez S-96: molecular weight 700,000; free acid form;

[0053] Gantrez S-97: molecular weight 1,500,000; free acid form; and

[0054] Gantrez MS-955: molecular weight 1,060,000; in the form of calcium / sodium salt.

[0055] A particularly preferred copolymer of maleic acid and methyl vinyl ether has a molecular weight of 1,000,000 or greater, with a particularly preferred material being Gantrez S-97.

[0056] The composition according to the invention may comprise a tooth whitening agent. The whitening agent preferably comprises a green and / or blue pigment. In the context of the present invention, a pigment is generally understood to be a hue / material which is insoluble in the relevant medium at the relevant temperature. This is in contrast to a soluble dye. In the context of the present invention, the "relevant medium" is human saliva, i.e. the liquid medium in which the composition is used during brushing at oral temperature, i.e. at most 37°C. As a reasonable approximation, the relevant medium can be considered to be water, and the relevant temperature is 25°C.

[0057] Preferably the blue pigment is Pigment Blue 15, more preferably Pigment Blue 15:1, 15:2, 15:3, 15:4, 15:5 or 15:6, most preferably 15: 1. A preferred pigment is Phthalocyanine Blue Pigment CI 74160 Blue Covarine.

[0058] A preferred green pigment is phthalocyanine green, preferably phthalocyanine green CI-74260.

[0059] Preferably, the total content of pigments in the composition is 0.01 wt% to 3 wt%, more preferably 0.02 to 2 wt%.

[0060] If the composition is a toothpaste, it may be a dual phase paste, with the whitening pigment being present in one phase.

[0061] The composition according to the invention may contain a water-soluble or slightly water-soluble metal salt source, preferably zinc ions such as zinc chloride, zinc acetate, zinc gluconate, zinc sulfate, zinc fluoride, zinc citrate, zinc lactate, zinc oxide, zinc monoglyceride, zinc tartrate, zinc pyrophosphate and zinc maleate; also preferably stannous ions such as stannous fluoride and stannous chloride.

[0062] The composition according to the invention may comprise an oral care enzyme system, such as an enzyme system generating hydrogen peroxide (e.g. the oxidoreductase glucose oxidase), amyloglucosidase, glucanase and / or mutagenase (optionally in the presence of a compound providing zinc ions and / or an 8-hydroxyquinoline derivative), lactoperoxidase, lactoferrin, lysozyme and mixtures thereof.

[0063] The compositions of the present invention may include a fluoride source such as sodium fluoride, stannous fluoride, sodium monofluorophosphate, ammonium zinc fluoride, ammonium stannous fluoride, calcium fluoride, ammonium cobalt fluoride, and mixtures thereof;

[0064] The composition according to the present invention may contain other ingredients commonly used in the art, such as:

[0065] Antimicrobial agents such as chlorhexidine, sanguinarine extract, metronidazole, quaternary ammonium compounds such as cetylpyridinium chloride; cetylpyridinium chloride clay complex biguanides such as chlorhexidine digluconate, hexetidine, octenidine, alexidine; and halogenated bisphenol compounds such as 2,2'methylenebis-(4-chloro-6-bromophenol);

[0066] Anti-inflammatory agents such as ibuprofen, flurbiprofen, aspirin, indomethacin, etc.;

[0067] anticaries such as sodium and stannous fluoride, amine fluorides, sodium monofluorophosphate, sodium trimetaphosphate, and casein;

[0068] plaque buffers, such as urea, calcium lactate, calcium glycerophosphate, and strontium polyacrylate;

[0069] Vitamins, such as vitamins A, C, and E;

[0070] Plant extracts;

[0071] Plant-derived antioxidants such as flavonoids, catechins, polyphenols and tannic acid compounds and mixtures thereof;

[0072] desensitizing agents, such as potassium citrate, potassium chloride, potassium tartrate, potassium bicarbonate, potassium oxalate, potassium nitrate, and strontium salts;

[0073] anticalculus agents, such as alkali metal pyrophosphates, hypophosphite-containing polymers, organic phosphonates, and phosphocitrates;

[0074] Biomolecules, such as bacteriocins, antibodies, enzymes, etc.;

[0075] flavorings, such as peppermint and spearmint oils;

[0076] Protein materials, such as collagen;

[0077] preservative;

[0078] sunscreen;

[0079] Hyaluronic acid;

[0080] Amino acids such as arginine;

[0081] Colorants;

[0082] pH adjusters;

[0083] Sweeteners;

[0084] Pharmaceutically acceptable carriers, such as starch, sucrose, water or water / alcohol system;

[0085] Surfactants, such as anionic, nonionic, cationic and zwitterionic or amphoteric surfactants;

[0086] Wetting agents, such as glycerin, sorbitol, propylene glycol, xylitol, lactitol, etc.;

[0087] Binders and thickeners, such as sodium carboxymethylcellulose, hydroxyethylcellulose xanthan gum, gum arabic, etc., and synthetic polymers such as polyacrylates and carboxyvinyl polymers, e.g.

[0088] Polymeric compounds that can enhance the delivery of active ingredients such as antimicrobial agents may also be included;

[0089] Buffering agents and salts to buffer the pH and ionic strength of the oral care composition; and

[0090] Other optional ingredients that may be included are, for example, bleaching agents, such as peroxy compounds, for example potassium peroxydiphosphate; effervescent systems, for example a sodium bicarbonate / citric acid system; color change systems, and the like.

[0091] method

[0092] The method for preparing the non-aqueous composition comprises the following sequential steps:

[0093] i) heating a mixture of a structurant and an organic polyol comprising sorbitol and / or glycerol to a temperature of 69° C. or higher,

[0094] ii) adding grinding agent and other non-flavoring ingredients to the mixture,

[0095] iii) rapidly cooling the resulting mixture at a cooling rate of 5° C. / min or more to form a paste or gel.

[0096] Preferably the process is carried out under vacuum. The vacuum may be achieved by any suitable means, preferably by a standard rotary vacuum pump capable of maintaining a vacuum of at least -800 mbar(g), preferably -950 mbar(g). Suitable examples.

[0097] The rapid cooling rate can be achieved by any suitable means, preferably by liquid nitrogen or carbon dioxide, preferably by using cardice (solid carbon dioxide). At pressures below 5.13 atmospheres and temperatures above -56.4°C, solid CO2 undergoes sublimation, changing state from solid to gas, with no intermediate liquid formed. At atmospheric pressure, sublimation occurs at a temperature of -78.5°C, with the associated enthalpy of sublimation being: ΔH sub = +25.2 kJ mol -1 (+571kJkg -1 ). The highly endothermic nature of this phase change dictates that it must be accompanied by the absorption of a large amount of heat from the surrounding material, allowing solid CO2 to act as an effective coolant.

[0098] The sublimation rate depends on the operating conditions of temperature, pressure and thermal properties of the fluids in contact with it, as well as the surface area of ​​the solid CO2 material. When intimately mixed with the product at an elevated temperature of 70°C in the mixer, sublimation occurs rapidly; up to 32 kg h-1 was measured during pilot plant operation. -1 The sublimation rate can be significantly slowed down with proper storage of the material in an insulated container, resulting in a sublimation rate as low as 0.19 kg h -1 sublimation rate.

[0099] CO2 is the preferred method for rapid cooling because it brings several other properties that make it advantageous for use as a directly added coolant. Gaseous CO2 is non-flammable, colorless and odorless, and is easily recovered from the mixing vessel via vacuum.

[0100] In an alternative embodiment, the coolant may be liquid nitrogen. Nitrogen exists as a colorless, low viscosity liquid at temperatures between 63.1 K and 77.3 K (or -221.8 °C and -195.9 °C) at atmospheric pressure. It can be readily obtained from air by cryogenic distillation or pressure swing adsorption. The associated enthalpy change of vaporization is +5.59 kJ mol -1 (+199.6kJ kg -1 ). It must be stored and transported in insulated vacuum bottles to minimize evaporation losses and maintain low temperature storage conditions.

[0101] Less preferably, the coolant may also be liquid carbon dioxide. Carbon dioxide exists as a liquid only at pressures above 5.13 atmospheres and at temperatures between -56.6°C (triple point temperature of CO2) and 31.1°C (critical temperature of CO2), so it needs to be stored under pressure. The associated enthalpy change of vaporization is +16.7 kJ mol -1 (+379.6kJ kg -1 ).

[0102] Preferably, the process has an initial cooling rate of the liquid ii) of less than 2°C / min (this is achieved by conventional cooling using a jacketed vessel with a coolant temperature in the range of 20°C to -18°C), followed by rapid cooling at a rate of 5°C / min or more (this is achieved by direct addition to a mixing vessel of liquid carbon dioxide or liquid nitrogen, or most preferably cardice).

[0103] Preferably, the mixture is cooled to 50°C to 40°C at an initial cooling rate of less than 2°C / min, preferably followed by the addition of temperature sensitive ingredients such as aromas and flavorings. After the initial slow cooling, the mixture is rapidly cooled to a temperature of 30°C or less at a rate of 5°C / min or more.

[0104] Preferably the rapid cooling rate is 10° C. / min, preferably 15° C. / min, more preferably 20° C. / min. Particularly preferred is a rapid cooling rate between 20° C. / min and 30° C. / min.

[0105] The aroma or flavoring agent is preferably added at a temperature of 45°C or below.

[0106] The invention will now be illustrated by the following non-limiting examples: the process of the invention is illustrated numerically and comparative examples are illustrated alphabetically. DETAILED DESCRIPTION

[0107] Example

[0108] The following examples were prepared using the following method:

[0109] Structuring components, such as various forms of carrageenan, various grades of PEG, xanthan gum or combinations thereof, are premixed, or optionally dissolved or dispersed in a portion of the bulk liquid and then added to a mixing vessel from the top along with the remaining bulk liquid phase. The entire in-vessel manufacturing process is carried out under a vacuum of at least -800 mbar (g) to minimize air entrainment. First, the liquid mixture in the container is heated to an elevated temperature of 60-80° C. and maintained for 30-60 minutes to activate and / or fully swell the structuring components. Next, the temperature may be maintained or reduced to as low as 50° C. before several sequential top additions of other solid active components and powder abrasives. These materials are dispersed and suspended by providing appropriate levels of mixing and shearing from an overhead agitator. After completing all solid addition and mixing steps, the product is cooled from an elevated temperature.

[0110] For Examples 1 and 2 relating to the proposed invention, rapid cooling was achieved by directly adding a mass of cardice equal to 14% to 17% of the total mass of the product. For both examples, flavorings and fragrances were added to the container immediately prior to the addition of the cardice as part of the same overhead addition process. The addition of solid cardice particles to the viscous, elevated temperature product resulted in their immediate and rapid sublimation, resulting in the formation of carbon dioxide gas, and in a rapid decrease in the temperature of the product, at rapid cooling rates between 10°C / min and 40°C / min. After cooling to the desired product fill temperature, the product was subjected to a further mixing stage to facilitate degassing.

[0111] For Comparative Examples A and B, cooling was achieved by circulating cooled silicone oil through a jacket surrounding the vessel. The product was first cooled to an intermediate temperature, preferably 45°C, at a cooling rate of 1.1-1.3°C / min. Flavors and fragrances were then added by final top addition at a conventional cooling rate of 0.6-0.8°C / min before the product was further cooled to the desired product filling temperature (30°C).

[0112]

[0113] After each batch was completed, viscosity measurements were taken at 25°C and 5 RPM for 60 seconds using a Brookfield viscometer model DV-I with a size E T-bar spindle.

Claims

1. A method for preparing a non-aqueous composition comprising the following steps in sequence: i) heating a mixture of a structurant and an organic polyol including sorbitol and / or glycerol to a temperature of 69° C. or higher, ii) adding grinding agent and other non-flavoring ingredients to the mixture, iii) rapidly cooling the resulting mixture at a cooling rate of 5° C. / min or more to form a paste or gel.

2. The method according to claim 1, wherein the method is carried out under vacuum.

3. A process according to claim 1 or claim 2 comprising an initial cooling rate of the mixture ii) of less than 2°C / min, followed by rapid cooling at a rate of 5°C / min or more.

4. The method according to claim 3, wherein the mixture ii) is cooled at a cooling rate of less than 2°C / min to obtain a mixture temperature of 50°C to 40°C, followed by rapid cooling iii) at a rate of 5°C / min or more to obtain a mixture temperature of 30°C or less.

5. The method according to any one of the preceding claims, wherein the rapid cooling rate iii) is 10°C / min or higher, preferably 15°C / min or higher, more preferably 20°C / min or higher.

6. A method according to any one of the preceding claims, wherein the rapid cooling is achieved by solid carbon dioxide.

7. A method according to any one of the preceding claims, wherein the aroma or flavouring is added at a mixture temperature of 45°C or less.

8. The method of any one of the preceding claims, wherein the structuring agent comprises carrageenan, PEG, xanthan gum, or mixtures thereof.

9. The method of claim 8, wherein the structuring agent comprises carrageenan.

10. The method of any one of the preceding claims, wherein the non-aqueous composition further comprises a calcium source and a phosphate source, wherein the calcium source and phosphate source, when delivered to a tooth, result in the in situ formation of hydroxyapatite on the tooth.

11. The method of claim 10, wherein the calcium source comprises calcium silicate and the phosphate source comprises trisodium phosphate, monosodium phosphate, and mixtures thereof.

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