Cosmetic composition

Abstract

To provide a composition that contains cholesterol in a stable manner, even when it contains an active ingredient having a carboxyl group. [Solution] (a) cholesterol, (b) a surfactant having a sterol skeleton, (c) water, and (d) an active ingredient, The cholesterol content of (a) is 0.001 to 0.1% by mass relative to the total amount of the composition. (b) The mass ratio of the surfactant having a sterol skeleton to (a) cholesterol ((b) surfactant having a sterol skeleton / (a) cholesterol is 5 or more, The surfactant having the sterol skeleton described in (b) above has a polyoxyethylene structure, and the number of moles of ethylene oxide added to the polyoxyethylene structure is 13 to 23. The cosmetic composition is provided in which the (d) active ingredient is at least one selected from the group consisting of compounds having a carboxyl group and salts or esters thereof.

Description

Technical Field

[0001] The present invention relates to a cosmetic composition containing cholesterol.

Background Art

[0002] Cholesterol is one of the components that form a lamellar structure in the stratum corneum of the epidermis, and plays an important role in maintaining the barrier function. It is believed that when the cholesterol synthesis capacity in the epidermis decreases, the barrier function is lowered and the resilience from rough skin is reduced. Therefore, with the expectation of the effects of maintaining the barrier function and improving rough skin and the like, cholesterol is widely blended in cosmetics, quasi-drugs, pharmaceuticals and the like. However, cholesterol is a solid oil-soluble substance at normal temperature, and has a problem of low solubility in cosmetic bases (particularly, aqueous cosmetic bases), making it difficult to stably incorporate the same.

[0003] Solubilization is known as a method for stably dispersing an oily component in an aqueous medium. Solubilization refers to thermodynamically stably incorporating a sparingly soluble or insoluble substance in water such as an oily component into an aqueous solvent using a solubilizing agent such as a surfactant to form a transparent or translucent liquid. Various oily materials have been attempted to be solubilized so far, but highly crystalline oily materials such as cholesterol are generally difficult to solubilize, and various studies on blending of alcohols, fatty acid esters and the like have been conducted. For example, Patent Document 1 discloses a solubilized composition characterized by blending a nonionic surfactant having an HLB in the range of 11 to 16, diglyceryl monoisostearate and / or diglyceryl monooleate, an anionic surfactant, cholesterol and / or phytosterol, and ethanol. Patent Document 2 discloses a transparent aqueous composition in which cholesterol is blended with a surfactant having a sterol skeleton at a specific ratio. As another method for stably dispersing an oily component in an aqueous medium, there is an emulsification method. However, the stable blending of cholesterol by the emulsification method has problems in use feel and stability.

Prior Art Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-227293 [Patent Document 2] International Publication No. WO2023 / 157851 [Overview of the project] [Problems that the invention aims to solve]

[0005] Our investigations have revealed that when the active ingredient of a cosmetic composition has a carboxyl group, even when cholesterol is combined with a surfactant having a sterol skeleton as described in Patent Document 2, precipitation and turbidity occur, making it difficult to obtain a stable composition. One embodiment of the present invention provides a composition containing cholesterol in a stable manner, even when it contains an active ingredient having a carboxyl group. [Means for solving the problem]

[0006] The present invention includes the following embodiments. [1] (a) cholesterol, (b) a surfactant having a sterol skeleton, (c) water, and (d) an active ingredient, The cholesterol content of (a) is 0.001 to 0.1% by mass relative to the total amount of the composition. (b) The mass ratio of the surfactant having a sterol skeleton to (a) cholesterol ((b) surfactant having a sterol skeleton / (a) cholesterol is 5 or more, The surfactant having the sterol skeleton described in (b) above has a polyoxyethylene structure, and the number of moles of ethylene oxide added to the polyoxyethylene structure is 13 to 23. The cosmetic composition wherein the (d) active ingredient is at least one selected from the group consisting of compounds having a carboxyl group and salts or esters thereof. [1-1] The cosmetic composition according to [1], wherein the (d) active ingredient is at least one selected from the group consisting of compounds having a carboxyl group and salts thereof. [2] The composition according to [1], wherein the (d) active ingredient comprises at least one selected from the group consisting of tranexamic acid, glycyrrhizic acid, glycyrrhetinic acid, and salts or esters thereof. [2-1] The cosmetic composition according to [1-1], wherein the (d) active ingredient comprises at least one selected from the group consisting of tranexamic acid, glycyrrhizic acid, and salts thereof. [3] The composition according to [1], [2], [1-1] or [1-2], further comprising (e) a polyol. [4] The composition according to any one of [1] to [3], [1-1], or [1-2], wherein the mass ratio of the (b) surfactant having a sterol skeleton to (a) cholesterol ((b) surfactant having a sterol skeleton / (a) cholesterol) is 6 to 10. [5] The composition according to any one of [1] to [4], wherein the content of the (d) active ingredient is 0.05 to 5% by mass with respect to the total amount of the composition. [6] The composition is a transparent composition, as described in any of [1] to [5], [1-1], or [1-2]. [7] The composition is an emulsified composition, as described in any of [1] to [5], [1-1], or [1-2]. [8] The composition described above is the composition according to any one of [1] to [7], [1-1], or [1-2], which does not contain phospholipids. [9] (a) The composition according to any one of [1] to [8], [1-1], or [1-2], wherein the cholesterol content is 0.01 to 0.08% by mass relative to the total amount of the composition.

[10] (b) The composition according to any one of [1] to [9], [1-1], or [1-2], wherein the content of the surfactant having a sterol skeleton is 0.005 to 1% by mass with respect to the total amount of the composition. [Effects of the Invention]

[0007] According to one embodiment of the present invention, a cosmetic composition (e.g., a transparent aqueous composition, a transparent oily composition, and an emulsified composition) is provided that can stably incorporate cholesterol even when it is included with an active ingredient having a carboxyl group. The transparent composition can be suitably used as a cosmetic, quasi-drug, pharmaceutical, etc. (e.g., a cosmetic or topical skin preparation). [Modes for carrying out the invention]

[0008] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and can be modified and implemented as appropriate without departing from its essence. The upper and lower limits of the numerical ranges described herein can be combined in any way. For example, if "X~Y" and "Z~W" are described, the ranges "X~W" and "Z~Y" are also included in the scope of the present invention as numerical ranges. Furthermore, unless otherwise specified, the numerical ranges "lower limit ~ upper limit" described herein mean that they are greater than or equal to the lower limit and less than or equal to the upper limit.

[0009] <<Cosmetic Composition>> A cosmetic composition according to one embodiment of the present invention (hereinafter also simply referred to as "cosmetic composition") comprises (a) cholesterol, (b) a surfactant having a sterol skeleton, (c) water, and (d) an active ingredient. In this embodiment, the content of (a) cholesterol is 0.001 to 0.1% by mass relative to the total amount of the composition, the mass ratio of (b) surfactant having a sterol skeleton to (a) cholesterol ((b) surfactant having a sterol skeleton / (a) cholesterol) (hereinafter also simply referred to as "(b) / (a) ratio") is 5 or more, the (b) surfactant having a sterol skeleton has a polyoxyethylene structure, the number of moles of ethylene oxide added to the polyoxyethylene structure is 13 to 23, and the (d) active ingredient is at least one selected from the group consisting of compounds having a carboxyl group and their salts or esters.

[0010] Through our research, we have found that when (d) compounds having a carboxyl group and their salts or esters are combined with (a) cholesterol as an active ingredient, precipitation and sedimentation tend to occur, making it difficult to obtain a composition with stable composition. According to the cosmetic composition of the embodiment, by using a specific (b) surfactant having a sterol skeleton and further setting the (b) / (a) ratio to 5 or higher, cholesterol can be stably incorporated even when a compound having a carboxyl group or its salt or ester is included as an active ingredient. If the (b) / (a) ratio is less than 5, cholesterol precipitation occurs, and stability decreases. From the viewpoint of reducing or suppressing cholesterol precipitate and sedimentation, the (b) / (a) ratio is preferably 6 or higher, more preferably 7 or higher. There is no particular upper limit to the (b) / (a) ratio, but from the viewpoint of usability, 10 or less is preferred, 9 or less is more preferred, and 8 or less is even more preferred. In some embodiments, the (b) / (a) ratio is preferably 5 to 10, more preferably 6 to 10, and even more preferably 6 to 9. In some embodiments, the (b) / (a) ratio may be 5 to 9, or 5 to 8, or 6 to 8. The reason why the cosmetic composition according to the embodiment has the above-described properties is not clear, but it is speculated as follows: Cholesterol has a tendency to orient itself at the water-oil interface of micelles (solubilization systems) and emulsions (emulsification systems), but (d) compounds and salts having a carboxyl group as an active ingredient are amphiphilic, and by acting on the water-oil interface, the interfacial equilibrium is disrupted, making it difficult to form a stable composition. By incorporating a specific amount of a specific (b) surfactant, the interface is stabilized, and (d) the active ingredient and (a) cholesterol are stably combined. However, the present invention is not limited to this mechanism. The components, physical properties, and uses of the cosmetic composition according to the embodiment will be described in detail below.

[0011] 1.Transparent composition In some embodiments, the cosmetic composition is a transparent aqueous composition. The transparent aqueous composition comprises (a) cholesterol, (b) a surfactant having a sterol skeleton, (c) water, and (d) an active ingredient. The transparent aqueous composition may optionally further comprise (e) a polyol and (f) other components ((f1) other oily components, (f2) other surfactants, (f3) other aqueous components).

[0012] In some embodiments, the cosmetic composition is a transparent oily composition. The transparent oily composition comprises (a) cholesterol, (b) a surfactant having a sterol skeleton, (c) water, (d) an active ingredient, (f1) other oily components, and (f2) other surfactants. The transparent oily composition may optionally further comprise (e) a polyol and (f) other components ((f3) other aqueous components).

[0013] As used herein, "transparent" means that no cloudiness or precipitate is visually observed. The transparent composition of the embodiment preferably has a light transmittance of 20% or more (preferably 40% or more, more preferably 60% or more, even more preferably 80% or more, particularly preferably 95% or more) at a wavelength of 700 nm. As used herein, the light transmittance at a wavelength of 700 nm can be measured with an ultraviolet-visible spectrophotometer. A "transparent" composition includes not only a completely transparent composition but also a "translucent" composition having a transmittance within the above range. As used herein, an "aqueous" composition refers to a composition in which the outer phase of the composition is an aqueous component. As used herein, an "oily" composition refers to a composition in which the outer phase of the composition is an oily component.

[0014] (a) Cholesterol Cholesterol is preferably from 0.001 to 0.1 mass% relative to the total amount (100 mass%) of the composition. When the cholesterol content is 0.001 mass% or more, the effects brought by incorporating cholesterol (for example, skin care effects such as enhanced moisturizing power) can be exhibited. In general, as the cholesterol concentration increases, sedimentation and clouding of cholesterol tend to occur more easily. When the content is 0.1 mass% or less, sedimentation and clouding of cholesterol can be prevented, enabling stable incorporation. From the viewpoint of stability (reduction and inhibition of cholesterol sediment and clouding), the content is more preferably 0.01 to 0.08 mass%, even more preferably 0.02 to 0.08 mass%, and particularly preferably 0.03 to 0.08 mass%.

[0015] (b) Surfactant having a sterol skeleton The cosmetic composition contains a surfactant having a sterol skeleton. By including the surfactant having a sterol skeleton together with cholesterol, cholesterol can be stably dispersed in water, whereby a composition with excellent transparency and reduced or inhibited cholesterol sedimentation and clouding can be obtained.

[0016] The surfactant having a sterol skeleton in the present invention is a surfactant having a sterol skeleton in the lipophilic group (hydrophobic portion). The sterol skeleton is an alcohol in which a hydroxy group is bonded to the 3-position of the cyclopentanohydrophenanthrene ring represented by the following formula, and the surfactant having a sterol skeleton is a compound in which a hydrophilic group is bonded to this sterol skeleton. The symbols A to D in the following formula represent the respective rings constituting the cyclopentanohydrophenanthrene ring, and the numbers represent the position numbers of the carbon atoms constituting the cyclopentanohydrophenanthrene ring. The sterol skeleton of the lipophilic group may have a double bond on the cyclopentanohydrophenanthrene ring.

[0017] [Chemical Formula]

[0018] Among these, sterols having a double bond in the B ring, or stanols composed of a saturated ring, are preferred. Specifically, examples include phytosterols such as β-sitosterol, campesterol, stigmasterol, and brassicasterol, or their stanols, cholesterol, cholestanol, lanosterol, and ergosterol, with phytosterols, phytostanols, cholesterol, and cholestanol being preferred, and phytosterols or cholesterol being more preferred.

[0019] The hydrophilic group is not particularly limited, but examples include nonionic hydrophilic groups such as polyoxyalkylene chains (e.g., polyoxyethylene (POE) chains, polyoxypropylene (POP) chains, etc.), polyglycerin, polyglucoside, sorbitan, and sucrose; anionic hydrophilic groups such as carboxylates, sulfonates, sulfates, and phosphates; and cationic hydrophilic groups such as aliphatic amine salts and quaternary ammonium salts. The alkylene in the polyoxyalkylene chain preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and even more preferably ethylene. In particular, the hydrophilic group is preferably a nonionic hydrophilic group, more preferably a polyoxyalkylene chain, and even more preferably a polyoxyethylene (POE) chain, and in particular, (b) surfactants having a sterol skeleton preferably have a polyoxyethylene structure. The number of moles of ethylene oxide (EO) added to the polyoxyethylene (POE) structure is not particularly limited, but is 13 or more, preferably 15 or more, more preferably 18 or more, and especially preferably 19 or more. Also, the number of moles of ethylene oxide (EO) added is 23 or less, preferably 22 or less, and even more preferably 21 or less. In some embodiments, the number of moles of ethylene oxide (EO) added is 13 to 23, preferably 15 to 22, more preferably 18 to 21, and especially preferably 19 to 21.

[0020] Surfactants having a sterol skeleton include, for example, those in which a polyoxyalkylene is ether-bonded to the sterol skeleton. More specifically, examples include, but are not limited to, polyoxyalkylene cholesteryl ethers (e.g., POE cholesteryl ether, POP cholesteryl ether), polyoxyalkylene phytosteryl ethers (e.g., POE phytosteryl ether, POP phytosteryl ether), polyoxyalkylene cholestanols (e.g., POE cholestanol, POP cholestanol), and polyoxyalkylene phytostanols (e.g., POE phytostanol, POP phytostanol). Among these, at least one of polyoxyethylene cholesteryl ether and polyoxyethylene phytosteryl ether is preferred as a surfactant having a sterol skeleton from the viewpoint of transparency and stability. Furthermore, POE(12-25, more preferably 15-24, even more preferably 18-22, particularly preferably 19-21) cholesterol and POE(12-25, more preferably 15-24, even more preferably 18-22, particularly preferably 19-21) phytosteryl ethers are preferred.

[0021] The HLB (Hydrophilic-Lipophilic Balance) of surfactants having a sterol skeleton is not particularly limited, but is preferably 11 or higher, and more preferably 12 or higher, in terms of improving transparency. Furthermore, the HLB of surfactants having a sterol skeleton is not particularly limited, but is preferably 16 or lower, and more preferably 15 or lower. The HLB of surfactants having a sterol skeleton is preferably in the range of 11 to 16, and more preferably in the range of 12 to 15. In this specification, unless otherwise specified, the HLB value is determined experimentally by comparing the emulsifying power with that of a standard sample.

[0022] Any surfactant having a sterol skeleton with the above-mentioned properties may be used, and commercially available products may also be used. Examples of commercially available products include, but are not limited to, the EMALEX CS series (EMALEX CS-15, EMALEX CS-20, EMALEX CS-24, etc.) manufactured by Nippon Emulsion Co., Ltd., and the NIKKOL BPS series (NIKKOL BPS-20, etc.) manufactured by Nikko Chemicals Co., Ltd.

[0023] These surfactants having a sterol skeleton can be used individually or in combination of two or more types.

[0024] The content of (b) surfactant having a sterol skeleton in the cosmetic composition is not particularly limited, but in terms of feel, it is preferably 0.005 to 1% by mass, more preferably 0.1 to 0.8% by mass, and even more preferably 0.15 to 0.5% by mass, relative to the total amount of the composition.

[0025] (c) water The type of water used is not particularly limited, as long as it is the type commonly used in cosmetics. For example, tap water, deionized water, distilled water, purified water, etc., can be used.

[0026] The water content is not particularly limited, but in the case of a transparent aqueous composition, from the viewpoint of transparency, it is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on the total amount of the composition. There is also no particular upper limit, but for example, it is 99.5% by mass or less, or 99% by mass or less. In some embodiments, the water content in the transparent aqueous composition is preferably 60 to 99.5% by mass, more preferably 70 to 99% by mass, and even more preferably 80 to 99% by mass, based on the total amount of the composition. The transparent aqueous composition may contain other aqueous components in addition to water. In terms of transparency, the proportion of (c) water in the aqueous component is preferably 60% by mass or more, more preferably 70% by mass, and even more preferably 80% by mass or more.

[0027] In some embodiments, the main component of the transparent aqueous composition is water, and it is a liquid.

[0028] In the case of a transparent oily composition, the water content is preferably 10% by mass or less, preferably 8% by mass or less, and preferably 5% by mass or less, relative to the total amount of the composition, from the viewpoint of transparency. Furthermore, the water content is 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and particularly preferably 3% by mass or more. In some embodiments, the water content in the transparent oily composition is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass, and even more preferably 3 to 5% by mass, based on the total amount of the composition. The transparent oily composition may contain other aqueous components in addition to water. In terms of transparency, the proportion of (c) water in the aqueous component is preferably 60% by mass or more, more preferably 70% by mass, and even more preferably 80% by mass or more.

[0029] (d) Active ingredients The cosmetic composition contains (d) at least one selected from the group consisting of compounds having a carboxyl group and salts or esters thereof as an active ingredient. In some embodiments, the cosmetic composition contains (d) at least one selected from compounds having a carboxyl group and salts thereof as an active ingredient. In this specification, "active ingredient" refers to an ingredient that can be listed as an active ingredient in a quasi-drug. Among compounds having a carboxyl group, for example, fatty acids are not included as active ingredients in this specification. Fatty acids refer to monocarboxylic acids and their derivatives having a chain-like hydrocarbon group (for example, an aliphatic hydrocarbon group having 2 or more carbon atoms). Examples of active ingredients include tranexamic acid, glycyrrhizic acid, glycyrrhetinic acid, salicylic acid, or their salts or esters, and tocopherol acetate. The salts are not limited as long as they are pharmaceutically or cosmetically acceptable, but examples include inorganic salts such as hydrochloride, nitrate, and sulfate; organic salts such as acetate, lactate, maleate, fumarate, tartrate, citrate, and methanesulfonate; organic amine salts such as monoethanolamine salt, diethanolamine salt, and triethanolamine salt; ammonium salts; alkali metal salts such as sodium salt and potassium salt; and alkaline earth metal salts such as magnesium salt. The ester is not particularly limited, but examples include esters of alcohols having 1 to 20 carbon atoms and compounds having a carboxyl group. The active ingredients may be used individually or in combination of two or more.

[0030] In some embodiments, (d) the active ingredient comprises at least one selected from the group consisting of tranexamic acid, glycyrrhizic acid, and salts or esters thereof. (d) By incorporating tranexamic acid, glycyrrhizic acid, glycyrrhetinic acid, or their salts or esters as active ingredients, the range of formulations can be broadened (making it possible to classify it as a quasi-drug and to enhance the effectiveness of the active ingredients), among other advantages. In some embodiments, (d) the active ingredient comprises tranexamic acid or a salt or ester thereof. Tranexamic acid is a known agent that is known to have anti-inflammatory and anti-allergic effects. Examples of tranexamic acid salts include, but are not limited to, sodium salts, potassium salts, ammonium salts, or salts with organic amines such as triethanolamine, arginine, or lysine. Examples of tranexamic acid esters include, but are not limited to, those in which the carboxyl group has been esterified, such as aliphatic alkyl esters such as methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, cetyl, or stearyl esters, and benzyl esters. In some embodiments, (d) the active ingredient comprises glycyrrhizic acid, glycyrrhetinic acid, or a salt or ester thereof. Glycyrrhizic acid is a known agent known to have anti-inflammatory and anti-allergic effects. Examples of salts or esters of glycyrrhizic acid include, but are not limited to, dipotassium glycyrrhizinate. Glycyrrhetinic acid is a known agent known to have anti-inflammatory and anti-allergic effects. Examples of salts or esters of glycyrrhetinic acid include, but are not limited to, stearyl glycyrrhetinate.

[0031] (d) The amount of active ingredient is adjusted according to the type of active ingredient so that (d) the amount of the active ingredient exerts its effect. (d) The amount of the active ingredient is preferably 0.05 to 5% by mass, more preferably 0.1 to 4% by mass, and even more preferably 0.15 to 3% by mass, based on the total amount of the composition. For example, (d) when the active ingredient is tranexamic acid or a salt or ester thereof, the amount of tranexamic acid or a salt or ester thereof is preferably 0.5 to 5% by mass, more preferably 0.7 to 4% by mass, and even more preferably 1 to 3% by mass. For example, (d) when the active ingredient is glycyrrhizic acid, glycyrrhetinic acid, or a salt or ester thereof, the amount of glycyrrhizic acid, glycyrrhetinic acid, or a salt or ester thereof is preferably 0.05 to 2% by mass, more preferably 0.1 to 1.5% by mass, and even more preferably 0.15 to 1% by mass.

[0032] (e) polyol The cosmetic composition may contain a polyol. Polyols are amphiphilic, and the inclusion of a polyol improves the dispersibility of cholesterol in water. When a cosmetic composition is a transparent aqueous composition or a transparent oil-based composition, the transparency of the composition may be improved by incorporating a polyol. The polyol is not particularly limited as long as it is commonly used in cosmetics. Examples include propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butylene glycol, isopentyl diol, pentylene glycol, hexanediol, caprylyl glycol, glycerin, diglycerin, polyglycerin, polyethylene glycol, and polyoxyethylene methyl glucoside. Among these, dihydric alcohols such as propylene glycol, 1,3-propanediol, 1,3-butylene glycol, pentylene glycol, and hexanediol are preferred from the viewpoint of improving dispersion stability and, in the case of transparent compositions, improving transparency. Polyols may be used individually or in combination of two or more types.

[0033] The polyol content in the transparent aqueous composition or transparent oily composition is not particularly limited, but from the viewpoint of improving the dispersibility of cholesterol and enhancing stability, it is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, based on the total amount of the composition. There is also no particular upper limit, but for example, it is preferably 1% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less.

[0034] (f) Other components (f1) Oily components other than cholesterol The transparent aqueous composition may contain oily components other than cholesterol. In this specification, "oil-based component" means a component commonly used as an oil-based component in the field of cosmetics. For example, it refers to a component whose solubility in water at 25°C is less than 0.1% by mass (less than 1 g / L). In this specification, oil-based components do not include surfactants (surfactants having a sterol skeleton as described above (b) or other surfactants as described below (f2)).

[0035] In some embodiments, the transparent aqueous composition contains phospholipids, preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0% by mass, based on the total amount of the composition; in other words, it does not contain phospholipids. In this specification, "phospholipid" means a compound (lipid) having a hydrocarbon chain containing one or more phosphate groups. The compositions of the present invention can stably incorporate cholesterol even without the inclusion of phospholipids. Examples of phospholipids include lecithin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, cardiolipin, phosphatidylinositol, phosphatidylglycerol, phosphatidylarachidonic acid, and phosphatidyleicosapentaenoic acid.

[0036] In the case of a transparent aqueous composition, a large amount of oily components other than cholesterol may adversely affect transparency, stability, etc. Therefore, in some embodiments, cholesterol is preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably substantially 100% by mass, of the total mass of oily components in the transparent aqueous composition. In some embodiments, the transparent aqueous composition is substantially free of oily components other than cholesterol (such as water-insoluble solvents). In some embodiments, the transparent aqueous composition is free of oily components other than cholesterol. By using a composition with a small amount or no oily components other than cholesterol, transparency and stability can be improved.

[0037] Other oily components besides cholesterol are not particularly limited, but examples include higher monoalcohols, hydrocarbons, ester oils, fats and oils, fatty acids, waxes, and silicone oils. These may be used individually or in combination of two or more.

[0038] The higher monoalcohol is not particularly limited, but linear forms are preferred, and more preferably linear higher monoalcohols having 12 to 22 carbon atoms (more preferably 14 to 22 carbon atoms, and even more preferably 16 to 22 carbon atoms). Specifically, examples include cetyl alcohol, stearyl alcohol, cetostearyl alcohol, behenyl alcohol, and the like. The hydrocarbons are not particularly limited, and examples include liquid paraffin, squalane, α-olefin oligomers, petrolatum, microcrystalline wax, and hydrogenated polyisobutene. The ester oils are not particularly limited and include, for example, cetyl 2-ethylhexanoate, ethylhexyl palmitate, 2-hexyldecyl 2-ethylhexanoate, octyldodecyl myristate, 2-hexyldecyl myristate, isononyl isononanoate, ethylhexyl isononanoate, isodecyl pivalate, isostearyl pivalate, 2-hexyldecyl stearate, isostearyl isostearate, isopropyl isostearate, pentaerythritol tetraisostearate, glyceryl tri-2-ethylhexanoate, caprylic / capric triglyceride, myristyl myristate, cetyl palmitate, and the like. There are no particular restrictions on the type of oil or fat used; examples include olive oil, shea butter, and grape seed oil. The wax used is not particularly limited; examples include jojoba oil, beeswax, and candelilla wax. The fatty acids used are not particularly limited; examples include myristic acid, palmitic acid, and stearic acid.

[0039] In some embodiments, the clear aqueous composition does not contain higher monoalcohols. In some embodiments, the clear aqueous composition does not contain hydrocarbons. In some embodiments, the clear aqueous composition does not contain ester oils. In some embodiments, the clear aqueous composition does not contain oils or fats. In some embodiments, the clear aqueous composition does not contain fatty acids. In some embodiments, the clear aqueous composition does not contain waxes. In some embodiments, the clear aqueous composition does not contain silicone oils.

[0040] The transparent oily composition contains oily components other than cholesterol.

[0041] In some embodiments, the transparent oily composition contains phospholipids preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0% by mass, based on the total amount of the composition, i.e., it does not contain phospholipids.

[0042] In the case of a transparent oily composition, a relatively large amount of oily components other than cholesterol is required from the viewpoint of stably dispersing cholesterol. In some embodiments, in the case of cleansing cosmetics such as cleansing compositions, a relatively large amount of oily components other than cholesterol, such as hydrocarbons and ester oils, is required from the viewpoint of enhancing cleansing power. In such forms, the content of oily components other than cholesterol (at least one selected from the group consisting particularly of hydrocarbons and ester oils) is preferably 10 to 70% by mass, more preferably 30 to 65% by mass, and even more preferably 50 to 65% by mass, based on the total amount of the composition. In some embodiments, when the composition is in the form of a transparent oily composition (for example, a cleansing cosmetic composition), the composition contains 0 to 60% by mass (preferably 5 to 40% by mass, more preferably 10 to 35% by mass) of hydrocarbons and 0 to 60% by mass (preferably 5 to 40% by mass, more preferably 10 to 35% by mass) of ester oils as oily components other than (f1) cholesterol, with the total amount of hydrocarbons and ester oils being 20 to 75% by mass (preferably 30 to 70% by mass, more preferably 40 to 65% by mass).

[0043] (f2) Other surfactants The transparent aqueous composition may optionally contain surfactants other than (b) surfactants having a sterol skeleton (other surfactants). Furthermore, the transparent oily composition contains (b) surfactants other than surfactants having a sterol skeleton (other surfactants). Other surfactants are not particularly limited, but may include alkyl ether surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene polyoxypropylene alkyl ethers; polyoxyethylene fatty acid esters; sorbitan fatty acid esters such as polyoxyethylene sorbitan fatty acid esters, sorbitan monopalmitate, and sorbitan oleate; polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene hydrogenated castor oil isostearate, polyoxyethylene sorbitol tetra fatty acid esters, polyoxyethylene phytosterols, lipophilic glyceryl monostearate and tetraglyceryl monostearate, glyceryl laurate, glycerin fatty acid esters such as polyglycerin fatty acid esters, sucrose fatty acid esters, polyethylene glycol distearate, etc., which may be used individually or in combination of two or more. Among these, it is preferable to use at least one of sorbitan monopalmitate, lipophilic glyceryl monostearate, and tetraglyceryl monostearate.

[0044] The content of other surfactants in the transparent aqueous composition is not particularly limited, but from the viewpoint of transparency and stability, 0 to 3% by mass and more preferably 0 to 1% by mass are preferred based on the total amount of the composition. In one embodiment, the transparent aqueous composition does not contain other surfactants. In particular, when the amount of oily components other than cholesterol is small (for example, less than 5% by mass of the total mass of oily components), such a small amount or no surfactant is preferred.

[0045] In transparent oily compositions (for example, cleansing cosmetics such as the cleansing compositions described above), if (f1) a large amount of hydrocarbons or ester oils are included as oily components other than cholesterol, the content of other surfactants is preferably 1 to 50% by mass (preferably 10 to 45% by mass, more preferably 20 to 40% by mass) of the total amount of the composition. Furthermore, the mass ratio of (f2) other surfactants to the total content of oily components other than cholesterol ((f2) / (f1)) is preferably 0.1 to 1.5, more preferably 0.3 to 1.0, and even more preferably 0.4 to 0.8.

[0046] (f3) Aqueous components other than water The transparent aqueous composition may contain aqueous components other than (c) water and (d) polyol. The aqueous components form the outer phase of the composition. Furthermore, the transparent oily composition may also contain aqueous components other than (c) water and (d) polyol. In this specification, “aqueous component” means a component commonly used as an aqueous component in the field of cosmetics. Aqueous components do not include surfactants (the above (b) surfactants having a sterol skeleton and (e2) other surfactants).

[0047] As aqueous components, for example, humectants, natural polymers, synthetic polymers, preservatives, and lower monoalcohols can be used. These may be used individually or in combination of two or more.

[0048] The humectant is not particularly limited, but examples include sugars such as sorbitol, mannitol, glucose, xylitol, maltitol, and trehalose; amino acids such as arginine, proline, serine, lysine HCl, threonine, valine, leucine, histidine, alanine, glycine, and carnosine; sodium pyrrolidone carboxylate, betaine, urea, sodium lactate, plant extracts, seaweed extracts, etc.

[0049] In addition, as aqueous components, although not particularly limited, natural polymers such as guar gum, carrageenan, xanthan gum, sodium hyaluronate, pullulan, agar, and alginate, as well as synthetic polymers such as hydroxyethylcellulose, hydroxymethylcellulose, carboxyvinyl polymer, polyacrylate, polyvinyl alcohol, and acrylic acid / alkyl methacrylate copolymer, and preservatives may be used.

[0050] The aqueous component may include a lower monoalcohol. Examples of lower monoalcohols include primary alcohols having 1 to 5 carbon atoms, and ethanol is preferred. For safety reasons, the lower monoalcohol content of the aqueous component should be low. The lower monoalcohol content is preferably 0 to 5% by mass, more preferably 0 to 3% by mass, and even more preferably 0 to 1% by mass, based on the total amount of the composition. In one embodiment, the transparent aqueous composition does not contain lower monoalcohol. Furthermore, when a lower monoalcohol is included, the mass ratio of the lower monoalcohol to (c) water (lower monoalcohol / water) is preferably 0.3 or less. More preferably, the mass ratio (lower monoalcohol / water) is 0.2 or less, and even more preferably 0.1 or less.

[0051] In addition, transparent aqueous compositions may be prepared by selecting raw materials as needed. In addition to the above components, the transparent aqueous composition may contain any other components commonly found in cosmetics, quasi-drugs, or pharmaceuticals. For example, humectants, antioxidants, UV absorbers, thickeners, pH adjusters, powder components, chelating agents, colorants, various skin nutrients and pharmaceuticals may be included as needed. Furthermore, in transparent oily compositions, raw materials can be selected and blended as needed. In addition to the above components, the transparent oily composition may contain any other components commonly found in cosmetics, quasi-drugs, or pharmaceuticals. For example, humectants, antioxidants, UV absorbers, thickeners, pH adjusters, powder components, chelating agents, colorants, various skin nutrients and pharmaceuticals may be included as needed.

[0052] (Method for producing a transparent aqueous composition) Transparent aqueous compositions can be manufactured according to standard methods. For example, (a) cholesterol and, if necessary, (e) polyols and (f1) other oily components, (b) a surfactant having a sterol skeleton and, if necessary, (f2) other surfactants, (c) water and, if necessary, (f3) other aqueous components, and (d) an active ingredient may be mixed by stirring in an appropriate order, and heated as necessary to homogenize.

[0053] For example, as will be explained in the following examples, it is preferable to first prepare a concentrated solution containing a high concentration of cholesterol (hereinafter also referred to as "concentrate") (concentrate preparation step), and then dilute the concentrate and add the active ingredient (dilution and active ingredient addition step). Preparing a concentrated solution containing a high concentration of cholesterol in advance and then diluting and adding the active ingredient is preferable because it allows for stable formulation while maintaining the activity of the active ingredient, and also suppresses cholesterol sedimentation and turbidity, resulting in a composition. Specifically, it is manufactured using the following method:

[0054] (i) Manufacturing process of concentrated liquid A concentrated solution is prepared by mixing (a) an oily component containing cholesterol and, if necessary, (d) a polyol and (e1) other oily components, and (b) a surfactant having a sterol skeleton and, if necessary, (e2) other surfactants, with an aqueous component containing (c1) water and, if necessary, (e3) other aqueous components, heating them to dissolve them uniformly. The cholesterol content in the concentrate is, for example, 3 to 10% by mass (more preferably 3 to 7% by mass, and even more preferably 3 to 5% by mass) relative to the total volume (total mass) of the concentrate. In some embodiments, the mass ratio of (c1) water to (a) cholesterol [(c1) / (a)] is 3 to 11. In these embodiments, the (c1) / (a) ratio is preferably 3 to 10, more preferably 4 to 9, and even more preferably 5 to 8.

[0055] The concentrate is preferably prepared by mixing an oily component containing (a) cholesterol and (b) a surfactant having a sterol skeleton in a non-aqueous system to dissolve (a) cholesterol in the oily component containing (b) the surfactant having a sterol skeleton, and then adding and mixing (c1) water and, if necessary, (e3) an aqueous component containing other aqueous components. By mixing (a) cholesterol and (b) the surfactant having a sterol skeleton in a non-aqueous system beforehand, a highly stable concentrate is obtained in which the oil phase component (oil droplets) containing cholesterol is stably dispersed in the aqueous phase component.

[0056] (ii) Dilution and addition of active ingredients Next, (c2) water and (d) the active ingredient are mixed with the concentrated liquid obtained above to obtain a cosmetic composition. The order and method of mixing (c2) water and (d) the active ingredient are not particularly limited. (c2) water and (d) the active ingredient may be added to the concentrate and mixed simultaneously, or one of (c2) water and (d) the active ingredient may be added to the concentrate first and mixed, and then the other may be added and mixed. Alternatively, (c2) water and (d) the active ingredient may be mixed beforehand and then mixed with the concentrate. In some embodiments, (c2) water is added first to obtain a diluent, and then (d) the active ingredient is added. (c2) The amount of water added should be adjusted to obtain the desired cholesterol concentration. The mixing temperature is not particularly limited. Typically, mixing takes place at a temperature of 10 to 40°C (more preferably 15 to 35°C, even more preferably 20 to 30°C, e.g., room temperature). The mixing means are also not particularly limited.

[0057] By the above manufacturing method, a transparent aqueous composition is obtained in which (a) cholesterol and (d) the active ingredient are stably dispersed in an aqueous medium containing water by adding a small amount of (b) a surfactant.

[0058] (Method for producing transparent oily compositions) Transparent oily compositions can be manufactured according to standard methods. For example, (a) cholesterol and, if necessary, (e) polyols and (f1) other oily components, (b) a surfactant having a sterol skeleton and, if necessary, (f2) other surfactants, (c) water and, if necessary, (f3) other aqueous components, and (d) an active ingredient may be mixed by stirring in an appropriate order, and heated as necessary to homogenize.

[0059] In some embodiments, the product can be manufactured by preparing a concentrated solution containing a high concentration of cholesterol (concentrate preparation step), diluting the concentrate, and adding an active ingredient (dilution and active ingredient addition step). (i) Manufacturing process of concentrated liquid The concentrate is preferably prepared by mixing an oily component containing (a) cholesterol and (b) a surfactant having a sterol skeleton in a non-aqueous system, similar to the case of the transparent aqueous composition described above, to dissolve (a) cholesterol in the oily component containing (b) the surfactant having a sterol skeleton, and then adding and mixing (c1) water and, if necessary, (e3) other aqueous components. By mixing (a) cholesterol and (b) the surfactant having a sterol skeleton in a non-aqueous system beforehand, a highly stable concentrate is obtained in which the oil phase component (oil droplets) containing cholesterol is stably dispersed in the aqueous phase component. The cholesterol content in the concentrate is, for example, 3 to 10% by mass (more preferably 3 to 7% by mass, and even more preferably 3 to 5% by mass) relative to the total volume (total mass) of the concentrate. In some embodiments, the mass ratio of (c1) water to (a) cholesterol [(c1) / (a)] is 3 to 11. In these embodiments, the (c1) / (a) ratio is preferably 3 to 10, more preferably 4 to 9, and even more preferably 5 to 8.

[0060] (ii) Dilution and addition of active ingredients Next, the concentrated liquid obtained above is mixed with (f1) an oily component containing other oily components, (f2) a surfactant containing other surfactants, (e) a polyol, (c2) water, and (d) an active ingredient in an appropriate order by stirring, and heated as necessary to homogenize it.

[0061] By the above manufacturing method, a transparent oily composition is obtained in which (a) cholesterol and (d) the active ingredient are combined with (b) a surfactant and (f2) a surfactant containing other surfactants, thereby stably dispersed in an oily component containing (f1) other oily components.

[0062] (Dosage form / use) The transparent composition of the present invention (a transparent aqueous composition or a transparent oily composition) can be in various dosage forms. Specifically, examples include, but are not limited to, mist, spray, lotion, etc.

[0063] The cosmetic composition of the present invention can be used as a cosmetic. Examples include skincare cosmetics such as lotions, emulsions, creams, serums, massage creams, face masks, hand creams, body lotions, body creams, sunscreens, cleansers (paste, liquid, foam), and cleansing agents (oil, milk, cream, gel, balm); finishing cosmetics such as foundations, eyeshadows, eyeliners, mascaras, eyebrow products, concealers, lipsticks, and lip balms; and hair cosmetics such as hair mists, treatments, hair creams, hair shampoos, and hair rinses. Methods of use include application by hand, fingers, or cotton, or by impregnation into nonwoven fabrics, etc.

[0064] The transparent composition of the present invention (a transparent aqueous composition or a transparent oily composition) is suitably used in quasi-drugs, pharmaceuticals, and the like. For example, if the cosmetic composition is a transparent aqueous composition or a transparent oily composition, it can also be used as a topical skin preparation. Examples include topical liquids, topical gels, creams, ointments, liniments, lotions, poultices, plasters, sprays, aerosols, etc. The methods of use can be the same as those for the cosmetic described above.

[0065] (characteristic) The transparent composition (transparent aqueous composition or transparent oil-based composition) of the present invention exhibits excellent transparency. The transparent aqueous composition or transparent oil-based composition has a light transmittance of 20% or more at a wavelength of 700 nm (preferably 40% or more, more preferably 60% or more, even more preferably 80% or more, and particularly preferably 95% or more). In some embodiments, the transparent composition (transparent aqueous composition or transparent oily composition) is free from turbidity and sedimentation. In some embodiments, the transparent composition (transparent aqueous composition or transparent oily composition) is solubilized.

[0066] The transparent aqueous composition of the present invention exhibits excellent stability. In one embodiment, the transparent aqueous composition shows no turbidity or precipitate after being left standing for one month at room temperature (e.g., 20-30°C, particularly 25°C) after preparation. In another embodiment, the transparent aqueous composition shows no turbidity or precipitate after being left standing for at least two weeks at high temperatures (e.g., 50-60°C, e.g., 50°C or 60°C) after preparation. The transparent oily composition of the present invention exhibits excellent stability. In one embodiment, the transparent oily composition shows no turbidity or sedimentation after being left to stand for at least one month (particularly at least three months) after preparation at room temperature (e.g., 20-30°C, particularly 25°C). In another embodiment, the transparent oily composition shows no turbidity or sedimentation after being left to stand for at least two weeks (particularly at least one month) after preparation at high temperatures (e.g., 50-60°C, for example 50°C or 60°C).

[0067] In some embodiments, the transparent aqueous composition is solubilized. In some embodiments, the transparent oily composition is solubilized. In this specification, "solubilization" refers to the state of a microemulsion. In some embodiments, the aqueous composition is in the form of an O / W type microemulsion. Such an aqueous composition can be produced, for example, by the production method described above. In some embodiments, the oily composition is in the form of a W / O type microemulsion. Such an oily composition can be produced, for example, by the production method described above. In some embodiments, the transparent aqueous composition is solubilized. In some embodiments, the transparent oily composition is solubilized. In this specification, solubilization is defined as a light transmittance of 95% or more at a wavelength of 700 nm.

[0068] 2. Emulsified composition In some embodiments, the cosmetic composition is an emulsifying composition. The emulsifying composition comprises (a) cholesterol, (b) a surfactant having a sterol skeleton, (c) water, (d) an active ingredient, (f1) other oily components, and (g) an emulsifier. The emulsifying composition may further optionally contain (e) a polyol and (f) other components ((f2) other surfactants, (f3) other aqueous components).

[0069] In this specification, "emulsified" composition refers to a composition in which oily components and aqueous components are mixed and homogenized by a surfactant or other emulsifying component. In some embodiments of emulsified compositions, an aqueous phase composed of aqueous components and an oily phase composed of oily components are included in a form in which one phase (dispersed phase) is uniformly dispersed as fine droplets in the other phase (continuous phase).

[0070] (a) cholesterol, (b) surfactants having a sterol skeleton, (d) active ingredients, (e) polyols, and (f2) other surfactants The preferred embodiments of (a) cholesterol, (b) surfactants having a sterol skeleton, (d) active ingredients, (e) polyols, and (f2) other surfactants, as well as their types, amounts, and proportions (mass ratios), are as described in the section "1. Transparent Compositions" above. In the case of an emulsified composition, the content of (e) polyol in the cosmetic composition tends to be higher than that in a clear aqueous composition, as it is also added for the purpose of maintaining the properties of the composition (for example, to improve the foaming of a paste-like composition). In some embodiments, when it is an emulsified composition, the content of (e) polyol in the cosmetic composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, based on the total amount of the composition. There is no particular upper limit, but for example, 30% by mass or less is preferred, and 25% by mass or less is more preferred.

[0071] (c) water Water can preferably be the type described in section 1, "Transparent Composition," above. The amount of water is not particularly limited, as long as it is sufficient to form a stable emulsified composition.

[0072] (f1) Other oily components (i) liquid oil The emulsified composition preferably contains liquid oil as another oily component. In this specification, liquid oil is not particularly limited as long as it is liquid at 25°C and is commonly used in cosmetics. Examples of liquid oils include hydrocarbon oils, ester oils, waxes, fats and oils, silicone oils, and ethers, with liquid oils having a viscosity of 50 mPa·s or less at 25°C being preferred. Among these, hydrocarbon oils and ester oils are preferred. Liquid oils can be used individually or in combination of two or more types.

[0073] (Hydrogen oil) As for hydrocarbon oils, any oil that is liquid at 25°C can be used, whether refined from petroleum crude oil or extracted from natural plants and animals. Specifically, examples include light isoparaffins, light liquid isoparaffins, liquid isoparaffins, and liquid paraffins.

[0074] (Ester oil) As ester oils, any ester of an alcohol and a fatty acid that is liquid at 25°C is preferably used. In particular, there are no limitations as long as the viscosity at 25°C is 50 mPa·s or less, and fatty acid esters of lower alcohols, fatty acid esters of higher alcohols, and fatty acid esters of polyhydric alcohols can be used. Among these, fatty acid esters of higher alcohols are preferred, and examples include isodecyl pivalate, isotridecyl isononanoate, 2-hexyldecyl stearate, and isostearyl isostearate.

[0075] (ii) Oily components other than liquid oil The emulsified composition may contain oily components other than liquid oil. Other oily components besides liquid oil are not particularly limited, but examples include higher monoalcohols, hydrocarbons, ester oils, fats and oils, fatty acids, waxes, and silicone oils. These may be used individually or in combination of two or more.

[0076] The higher monoalcohol is not particularly limited, but linear forms are preferred, and more preferably linear higher monoalcohols having 12 to 22 carbon atoms (more preferably 14 to 22 carbon atoms, and even more preferably 16 to 22 carbon atoms). Specifically, examples include cetanol, stearyl alcohol, cetostearyl alcohol, behenyl alcohol, and the like. The hydrocarbons are not particularly limited, and examples include squalane, sugar squalane, α-olefin oligomers, petrolatum, and microcrystalline wax. The ester oil is not particularly limited, and for example, fatty acid esters of lower alcohols, fatty acid esters of higher alcohols, or fatty acid esters of polyhydric alcohols, which have a viscosity of more than 50 mPa·s at 25°C, can be used. There are no particular restrictions on the type of oil or fat used; examples include olive oil, shea butter, and grape seed oil. The wax used is not particularly limited; examples include jojoba oil, beeswax, and candelilla wax. The fatty acids are not particularly limited, and examples include myristic acid, palmitic acid, stearic acid, and lauric acid. Fatty acids may be added to a detergent composition to form a soap base or to adjust the properties of the composition. Emulsified compositions are typically selected for their intended use and dosage form, including (f1) other oily components.

[0077] (Non-cleaning agent form) In some embodiments, when the emulsified composition is in the form of a non-cleansing agent (emulsified lotion, cream, etc.), (f1) the other oily component preferably includes liquid oil, and (f1) the proportion of liquid oil in the other oily component is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. (f1) The content of other oily components is preferably 1 to 50% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 15% by mass, based on the total amount of the composition. In order to form a stable emulsion, it is preferable that (g) emulsifiers such as nonionic surfactants be blended in a manner of preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total amount of the composition. Hydrocarbon oils (liquid paraffin, squalane, etc.) and ester oils (ethylhexyl palmitate, etc.) are preferably used as liquid oils.

[0078] (Detergent form) In some embodiments, when the cosmetic composition is an emulsified composition in the form of a cleansing agent such as a facial cleansing paste, it is preferable that (f1) other oily components include fatty acids that serve as the base for the cleansing components (preferably the proportion of fatty acids in (f1) other oily components is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more). Furthermore, it is preferable that the composition also includes a pH adjusting agent (alkaline agent) for neutralizing the fatty acids. For example, it is preferable that a pH adjusting agent (alkaline agent) such as potassium hydroxide is blended in an amount of preferably 1 to 15% by mass, more preferably 3 to 12% by mass, and even more preferably 5 to 10% by mass of the total amount of the composition. Furthermore, it is preferable that the composition contains (e) polyol in an amount of 5 to 35% by mass, more preferably 10 to 30% by mass, and even more preferably 15 to 25% by mass, based on the total amount of the composition.

[0079] (f3) Other aqueous components Other aqueous components may preferably be those described in section "1. Transparent Composition" above.

[0080] (g) Emulsifier The emulsified composition contains (g) an emulsifier. The emulsifier is not particularly limited as long as it is one that is commonly used as an emulsifier in the field of cosmetics. For example, a nonionic surfactant can be used as an emulsifier. Nonionic surfactants include, for example, alkyl ether surfactants such as polyoxyethylene alkyl ether and polyoxyethylene polyoxypropylene alkyl ether; polyoxyethylene fatty acid esters; sorbitan fatty acid esters such as polyoxyethylene sorbitan fatty acid ester, sorbitan monopalmitate, and sorbitan oleate; glycerin fatty acid esters such as polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene hydrogenated castor oil isostearate, polyoxyethylene sorbitol tetra fatty acid ester, polyoxyethylene phytosterol, glyceryl stearate and tetraglyceryl stearate, glyceryl laurate, polyglycerin fatty acid ester, sucrose fatty acid ester, polyethylene glycol distearate, etc., which may be used individually or in combination of two or more. Among these, it is preferable to use at least one of glycerin fatty acid esters such as glyceryl stearate, ethylene oxide (POE) surfactants containing polyoxyethylene chains, and fatty acid monoesters such as sorbitan fatty acid esters. (Method for producing emulsified compositions) The emulsified composition can be manufactured according to standard methods. For example, a cosmetic composition can be obtained by preparing a concentrate (concentrate preparation step) in the same manner as the method for producing the transparent aqueous composition described above, and then adding the concentrate obtained above to a composition obtained by mixing (c2) water, (f3) other oily components, (g) emulsifier, and (d) active ingredient. Alternatively, a method may be used in which (a) cholesterol is dissolved in (d) polyol, (e1) other oily components to form an oil phase component (oil phase portion) containing cholesterol, and then (c2) water, (g) emulsifier, and (d) active ingredient are mixed to emulsify. Alternatively, an emulsion composition may be prepared by mixing an oil phase containing (e1) other oily components (e.g., fatty acids or liquid oils) and (g) an emulsifier with (c) water and, if necessary, (f3) other aqueous components in an aqueous phase, and then adding the separately prepared concentrate to the resulting emulsion composition and mixing. In this case, (d) the active ingredient may be incorporated into the aqueous phase beforehand, but it is preferable to add it to the emulsion composition together with the concentrate.

[0081] (Dosage form / use) The emulsified composition of the present invention can be in various dosage forms. The emulsifying composition of the present invention can be preferably used in the dosage forms and applications described in "1. Transparent Compositions" above. One embodiment of the present invention includes, but is not limited to, emulsified lotions, oils, emulsions, creams, pastes (e.g., facial cleansing pastes), balms, gels, and the like. [Examples]

[0082] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. It is not limited to that. Note that the amounts and content of each component in the table are converted to pure content and are expressed in "mass %" unless otherwise specified. Furthermore, unless otherwise specified, the examples were conducted at room temperature. "Room temperature" typically refers to a range of approximately 10°C to 35°C.

[0083] <Composition ingredients> The components used in the following examples are as follows. In the following, POE refers to a polyoxyethylene chain, and the number in parentheses following it indicates the number of moles added.

[0084] (Surfactants) (b) Surfactants having a sterol skeleton • EMALEX CS-20 (manufactured by Nippon Emulsion Co., Ltd.): Polyoxyethylene (POE20) cholesteryl ether (HLB: 12) • EMALEX CS-24 (manufactured by Nippon Emulsion Co., Ltd.): Polyoxyethylene (POE24) cholesteryl ether (HLB: 13) • EMALEX CS-10 (manufactured by Nippon Emulsion Co., Ltd.): Polyoxyethylene (POE10) cholesteryl ether (HLB:10) 2. Other common surfactants • NIKKOL HCO-60 (manufactured by Nikko Chemicals Co., Ltd.): POE(60) hydrogenated castor oil (HLB: 14.0) • Sunsoft Q-172Y (manufactured by Taiyo Kagaku Co., Ltd.): Polyglyceryl-10 dioleate (HLB: 11.9)

[0085] (d) Active ingredients Tranexamic acid • Dipotassium glycyrrhizinate (GK2) Stearyl glycyrrhetinate

[0086] (e) polyol BG: 1,3-butylene glycol • 1,3-propanediol Glycerin • PEG-8: Polyethylene glycol (POE8)

[0087] (f) Oil phase • Liquid oil: Ester oil or hydrocarbon oil (g) Emulsifier Nonionic surfactant A: Ethylene oxide-based surfactant Nonionic surfactant B: Glycerin fatty acid ester Nonionic surfactant C: Fatty acid monoester

[0088] 1. Preparation of aqueous cosmetic composition Aqueous cosmetic compositions with the compositions shown in Tables 1 to 5 were prepared using the following procedure. (1) Preparation of the concentrate First, the ingredients other than purified water ((a) cholesterol, (b) surfactant, (e) polyol) were mixed and heated to 85°C to dissolve the cholesterol in the solution. Then, (c1) water heated to 85°C was added and stirred with a stirrer to obtain a concentrated solution (concentrate). (2) Dilution and addition of active ingredients At a temperature of 25°C, (c2) purified water and (d) the active ingredient were added to the concentrate and stirred to obtain an aqueous cosmetic composition. The compositions in Tables 3-6 were prepared using the same procedure without adding (d) the active ingredient.

[0089] The compositions of the examples prepared above (A-3 to A-6, B-3 to B-6) and the reference examples (C-2 to C-6) were all transparent. On the other hand, the compositions of the comparative examples (A-1 to A-2, B-1 to B-2) and the reference example (C-1) showed cloudy precipitation or sedimentation. The aqueous cosmetic compositions prepared above were evaluated for stability, and the results are shown in Tables 1 to 6.

[0090] <Stability Evaluation> The cosmetic compositions prepared in the above examples and comparative examples were allowed to stand for two weeks at 60°C. After standing, the cosmetic compositions were visually inspected for the presence of sediment and precipitates, and evaluated according to the following criteria. Note that "sediment" refers to a slight precipitate that can barely be seen after stirring, while "sediment" refers to something that is clearly visible. (Judgment criteria) A: Colorless and clear, without sediment or precipitate. B: The Lord has been found C: Precipitation occurs.

[0091] <Result> [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] [Table 4]

[0095] [Table 5]

[0096] From the results in Tables 1 and 2, it was confirmed that the compositions of the examples in which (a) cholesterol was blended with (b) a surfactant having a sterol skeleton in a ratio of 5 or more (b) / (a) (mass ratio) yielded a transparent aqueous composition with excellent stability (stability rating: B or higher), even when containing the active ingredient (d) (tranexamic acid or GK2), which is a compound having a carboxyl group or a salt thereof. Furthermore, the compositions of the examples in which (b) a surfactant having a sterol skeleton was blended in a ratio of 6 or more (b) / (a) yielded a transparent composition with even higher stability (stability rating: C or higher), with no plaques or precipitates observed. On the other hand, in comparative examples where the (b) / (a) ratio (mass ratio) was 4 or less, cholesterol sediment or precipitate was observed at the bottom.

[0097] Tables 3 to 5 show the evaluation results for compositions that do not contain an active ingredient. As shown in Tables 3 and 4, when the active ingredient was not present, high stability (stability rating: C or higher) was achieved by incorporating (b) surfactants having a sterol skeleton in a (b) / (a) ratio (mass ratio) of 4 or more. As shown in Table 5, when the number of moles of ethylene oxide added (POE) of surfactants having a sterol skeleton (b) falls outside the range of 13-23 (E-3, E-4), or when the (b)' surfactant other than surfactants having a sterol skeleton (E-1, E-2) has a (b)' / (a) ratio (mass ratio) of 5 or more is 5, cholesterol sediment or precipitate was observed at the bottom.

[0098] 2. Preparation of emulsified cosmetic composition Emulsified cosmetic compositions with the compositions shown in Table 6 were prepared using the following procedure. (1) Preparation of the concentrate First, the ingredients other than purified water ((a) cholesterol, (b) surfactant, (e) polyol) were mixed and heated to 85°C to dissolve the cholesterol in the solution. Then, (c1) water heated to 85°C was added and stirred with a stirrer to obtain a concentrated solution (concentrate). (2) Preparation of aqueous component solution At a temperature of 25°C, (c2) purified water and (d) the active ingredient were added to the concentrate and stirred to obtain an aqueous component solution. (3) Preparation of oily component solution The oil phase additive components (oil component (f) and emulsifier (g)) were mixed and heated to 80-90°C to dissolve and prepare an oil component solution. (4) Preparation of emulsified composition Then, the oily component solution was gradually added to the aqueous component solution while stirring, and the mixture was stirred in an emulsifier to obtain an emulsified cosmetic composition.

[0099] <Stability Evaluation> The cosmetic compositions prepared in the above examples were left to stand for one week at 50°C. After standing, the cosmetic compositions were visually inspected for separation and evaluated according to the following criteria. (Judgment criteria) A: No significant changes from the initial characteristics. B: A very slight separation occurs. C: Clear separation occurs.

[0100] [Table 6]

[0101] Table 6 shows that by combining (a) cholesterol with (b) a surfactant having a sterol skeleton in a (b) ratio (mass ratio) of 5 or more (b) / (a), an emulsified composition with excellent stability (stability evaluation: A or higher) can be obtained, even when it contains an active ingredient (d) which is a compound having a carboxyl group or a salt thereof (tranexamic acid or GK2).

[0102] 3. Preparation of cleansing composition (oil-based cosmetic composition) Cleansing compositions with the compositions shown in Table 7 were prepared using the following procedure. (1) Preparation of Phase A At room temperature, the raw materials for phase A (f1-1), (f1-2), (f2-1) to (f2-4), (d) active ingredient, and (c2) water) from Table 7 were added in that order from top to bottom, mixed, and homogenized to obtain phase A. (2) Preparation of Phase B (concentrate) At room temperature, the raw materials for phase B ((a) cholesterol, (b) surfactant, (e) polyol, (c1) water) listed in Table 7 were added in order, mixed, and homogenized to obtain the concentrated liquid (concentrate) which is phase B. (3) Mixture At room temperature, phase A and phase B (concentrate) were mixed to obtain cleansing compositions (G-1, G-2). In Table 7, (f1-1), (f1-2), and (f2-1) to (f2-4) are the following components, respectively. (f1-1): Hydrocarbons (oil components) (f1-2): Ester oil (oily component) (f2-1): Nonionic surfactant (polyoxyethylene sorbitol tetra fatty acid ester) (f2-2): Nonionic surfactant (sorbitan fatty acid ester) (f2-3): Nonionic surfactant (glycerin fatty acid ester) (f2-4): Nonionic surfactant (sorbitan fatty acid ester)

[0103] The cleansing compositions (G-1, G-2) prepared in the above examples were all transparent compositions. The cleansing compositions (G-1, G-2) prepared as described above were evaluated for stability, and the results are shown in Table 7.

[0104] <Stability Evaluation> The cleansing compositions were left to stand under three conditions: (1) 60°C for 2 weeks (2W), (2) 50°C for 1 month (1M), or (3) 25°C for 3 months (3M). After standing, the compositions were visually inspected for the presence of sediment and precipitates, and evaluated according to the following criteria. Note that "sediment" refers to a slight precipitate that can barely be seen after stirring, while "sediment" refers to something that is clearly visible. (Judgment criteria) A: Colorless and clear, without sediment or precipitate. B: The Lord has been found C: Precipitation occurs.

[0105] <Result> [Table 7]

[0106] The results in Table 7 show that the compositions of the examples in which (a) cholesterol was blended with (b) a surfactant having a sterol skeleton in a (b) / (a) ratio (mass ratio) of 5 or more contained the active ingredient (d) (stearyl glycyrrhetinate), which is an ester of a compound having a carboxyl group. Even when the content of oily components other than cholesterol, such as (f1-1) hydrocarbons and (f1-2) ester oils, was high, no plaques or precipitates were observed, and it was confirmed that a transparent oily composition with excellent stability (stability evaluation: A) was obtained. In particular, the compositions of these examples showed excellent stability at high temperatures (at least 50°C for 1 month, and at least 60°C for 2 months). Furthermore, at room temperature (25°C), they showed excellent stability for at least 3 months.

[0107] 4. Preparation of facial cleansing paste composition (emulsified cosmetic composition) A facial cleansing paste composition with the composition shown in Table 8 was prepared using the following procedure. (1) Preparation of Phase A (oil phase) The raw materials for phase A ((f1-1)~(f1-2), (e)'~(e)'' polyol, (f1-3), (e)''' polyol, (g) emulsifier) ​​listed in Table 8 were added in order, heated to 80°C, mixed, and uniformly dissolved to obtain phase A. (2) Preparation of Phase B (aqueous phase) The raw materials for phase B ((f3-1) to (f3-2), (c2) water) listed in Table 8 were added in order, heated to 80°C, mixed, and uniformly dissolved to obtain phase B. (3) Emulsification Phase B, prepared in (2) above, was gradually added to Phase A, prepared in (1) above, while stirring, and emulsified. (4) Preparation of Phase D (concentrate) At room temperature, the raw materials for phase D ((a) cholesterol, (b) surfactant, (e) polyol, (c1) water) listed in Table 8 were added in order, mixed, and homogenized to obtain the concentrated liquid (concentrate) which is phase D. (5)Mixture (3) The emulsion obtained in (3) was mixed with phase C ((d) active ingredient) and phase D (concentrate), and while stirring, it was cooled to 40°C and homogenized. The stability of the facial cleansing paste compositions (H-1, H-2) prepared as described above was evaluated as follows, and the results are shown in Table 8. Note that in Table 8, (f1-1)~(f1-3), (e)', (e)'', (e)''' 、 (g), (f3-1), and (f3-2) are the following components, respectively. (f1-1)~(f1-3): Fatty acid (oily component) (e)', (e)'', (e)''': polyols (g): Emulsifier: Nonionic surfactant (glycerin fatty acid ester) (f3-1): pH adjuster (alkaline agent) (f3-2): Preservative

[0108] <Stability Evaluation> The facial cleansing paste composition was left to stand under two conditions: (1) 35°C for 3 months (3M) or (2) 25°C for 3 months (3M). After standing, the composition was visually inspected for separation and evaluated according to the following criteria. (Judgment criteria) A: No significant changes from the initial characteristics. B: A very slight separation occurs. C: Clear separation occurs.

[0109] <Result> [Table 8]

[0110] From the results in Table 8, it was confirmed that the example composition, in which (a) cholesterol was blended with (b) a surfactant having a sterol skeleton in a (b) / (a) ratio (mass ratio) of 5 or more, contained the active ingredient (d) (dipotassium glycyrrhizinate; GK2), which is a salt of a compound having a carboxyl group, and even when the content of fatty acids (f1-1) to (f1-3) as oily components other than cholesterol was large, no separation was observed, and an emulsified composition with excellent stability (stability evaluation: A) was obtained. Generally, cleansing compositions containing fatty acid soaps tend to have poor stability due to structural dissolution or precipitation of fatty acids, as well as emulsification breakdown in high-temperature environments. However, the above facial cleansing paste compositions (H-1, H-2) showed excellent stability over a long period (at least 3 months) at around room temperature.

[0111] Although preferred embodiments and examples of the present invention have been described above, the present invention is not limited thereto. Additions, omissions, substitutions, and other modifications to the configuration are possible without departing from the spirit of the present invention. [Industrial applicability]

[0112] The cosmetic composition of the present invention has excellent stability while containing active ingredients and cholesterol, and can be suitably used, for example, as a cosmetic or topical skin preparation.

Claims

1. (a) Cholesterol, (b) a surfactant having a sterol skeleton, (c) water, and (d) an active ingredient, The cholesterol content of (a) is 0.001 to 0.1% by mass relative to the total amount of the composition. (b) The mass ratio of the surfactant having a sterol skeleton to (a) cholesterol ((b) surfactant having a sterol skeleton / (a) cholesterol) is 5 or more. The surfactant having the (b) sterol skeleton has a polyoxyethylene structure, and the number of moles of ethylene oxide added to the polyoxyethylene structure is 13 to 23. The cosmetic composition wherein the (d) active ingredient is at least one selected from the group consisting of compounds having a carboxyl group and salts or esters thereof.

2. The composition according to claim 1, wherein the (d) active ingredient comprises at least one selected from the group consisting of tranexamic acid, glycyrrhizic acid, glycyrrhetinic acid, and salts or esters thereof.

3. The composition according to claim 1 or 2, further comprising (e) a polyol.

4. The composition according to claim 1 or 2, wherein the mass ratio of the surfactant having a sterol skeleton to cholesterol ((b) surfactant having a sterol skeleton / (a) cholesterol) is 6 to 10.

5. The composition according to claim 1 or 2, wherein the content of the active ingredient (d) is 0.05 to 5% by mass with respect to the total amount of the composition.

6. The composition according to claim 1 or 2, wherein the composition is a transparent composition.

7. The composition according to claim 1 or 2, wherein the composition is an emulsified composition.

8. The composition according to claim 1 or 2, wherein the composition does not contain phospholipids.

9. (a) The composition according to claim 1 or 2, wherein the cholesterol content is 0.01 to 0.08% by mass of the total amount of the composition.

10. (b) The composition according to claim 1 or 2, wherein the content of the surfactant having a sterol skeleton is 0.005 to 1% by mass with respect to the total amount of the composition.

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