Two-layer external component

Abstract

This invention provides a novel topical composition containing azelaic acid. [Solution] A two-layer topical composition containing (A) azelaic acid and (B) a surfactant.

Description

Technical Field

[0001] The present invention relates to a two-layer external composition.

Background Art

[0002] Azelaic acid is a compound that has been used as an active ingredient of acne treatment agents. Patent Document 1 describes a cream or emulsion containing azelaic acid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since azelaic acid is a component that is poorly soluble in water, it is difficult to formulate it into a formulation with a high water content such as lotion. In addition, when azelaic acid is dissolved, precipitation over time or under severe temperature conditions is a concern. Therefore, in conventional azelaic acid-containing formulations, the main formulation means is to disperse azelaic acid into a high-viscosity emulsion without dissolving it. On the other hand, users of cosmetics containing azelaic acid tend to seek a refreshing and moist feeling of use. However, it has been difficult to obtain the feeling of use required by users with conventional cosmetics obtained by the method of dispersing azelaic acid into a high-viscosity emulsion.

[0005] Therefore, an object of the present invention is to provide a novel external composition containing azelaic acid.

Means for Solving the Problems

[0006] The inventors conceived the idea of ​​including azelaic acid in a powder form within the topical composition, rather than dissolving it, in order to obtain a topical composition with a refreshing and moisturizing feel. As a result of their diligent research, the inventors discovered that by combining azelaic acid and a surfactant and including them in an aqueous component, a two-layer topical composition having a powder layer containing azelaic acid can be obtained.

[0007] The present invention provides, for example, the following [1] to

[13] . [1] A two-layer topical composition containing (A) azelaic acid and (B) a surfactant. [2] (C) The two-layer topical composition according to [1], further containing a metal salt. [3] The two-layer topical composition according to [2], wherein component (C) is one or more selected from aluminum salts, magnesium salts, calcium salts, potassium salts, and sodium salts. [4] The two-layer external composition according to [2] or [3], comprising two or more metal salts for component (C). [5] A two-layer topical composition according to any one of [2] to [4], comprising component (C) aluminum chlorohydrate. [6] (D) A two-layer external composition according to any one of [1] to [5], further containing a water-soluble polymer. [7] The two-layer topical composition according to [6], wherein component (D) is one or more selected from anionic polymers, cationic polymers, cellulose derivatives, and pullulan. [8] The two-layer topical composition according to [6] or [7], comprising component (D) hydroxyethylcellulose. [9] A two-layer topical composition according to any one of [1] to [8], wherein the pH of the two-layer topical composition is 2.0 to 6.0.

[10] A two-layer topical composition according to any one of [1] to [9], wherein the HLB value of component (B) is 8 to 19.

[11] A two-layer topical composition according to any one of [1] to

[10] , wherein component (B) is a component having a polyoxyethylene chain.

[12] A two-layer topical composition according to any one of [1] to

[11] , further containing (E) water, wherein the content of component (E) is 60% by mass or more based on the total amount of the two-layer topical composition.

[13] A two-layer topical composition according to any one of [1] to

[12] , further containing (F) a polyhydric alcohol, wherein the content of component (F) is 30% by mass or less based on the total amount of the two-layer topical composition. [Effects of the Invention]

[0008] According to the present invention, a novel topical composition containing azelaic acid can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a photograph showing the results in Test Example 1. [Figure 2] Figure 2 is a photograph showing the results in Test Example 3. [Modes for carrying out the invention]

[0010] The embodiments for carrying out the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[0011] In the numerical ranges described herein in stages, the upper or lower limit of one stage of the numerical range may be arbitrarily combined with the upper or lower limit of another stage of the numerical range. In the numerical ranges described herein, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. Unless otherwise specified, the components or materials exemplified herein may be used individually or in combination of two or more.

[0012] The two-layer external composition of this embodiment is a composition that, when left standing, has two visually distinct layers, and the interface between the two layers can be visually confirmed. The two-layer external composition of this embodiment has an upper layer and a lower layer, more specifically, an upper layer (also called the liquid layer) mainly containing a liquid component, and a lower layer (also called the powder layer) formed by the precipitation of powder components in the liquid component. Preferably, the two-layer external composition of this embodiment is a composition in which, when the brightness (L* value) of the liquid layer and the powder layer is measured (the measurement method will be described later), the difference (ΔL) between the L* value of the liquid layer and the L* value of the powder layer is 10 or more when left standing (for example, after 24 hours).

[0013] The two-layer topical composition of this embodiment is a novel topical composition that differs from conventional compositions in that it contains azelaic acid in powder form. Because this two-layer topical composition can be formulated with a high water content, it can provide a refreshing and moisturizing feel that could not be obtained with conventional topical compositions containing azelaic acid. Furthermore, this two-layer topical composition has an excellent appearance due to the clearly formed interface between the liquid layer and the powder layer, the high height of the powder layer resulting in a fluffy appearance, and the low likelihood of powder caking. In addition, because the azelaic acid disperses quickly when shaken, this two-layer topical composition has good azelaic acid redispersibility and is easy to handle during use.

[0014] The two-layer topical composition of this embodiment contains (A) azelaic acid (hereinafter also referred to as "component (A)") and (B) a surfactant (hereinafter also referred to as "component (B)").

[0015] Most of the azelaic acid, which is component (A), exists as a powder layer in the lower layer of the two-layer topical composition without dissolving in the liquid layer. The content of component (A) may be 0.1% by mass or more, 0.3% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total amount of the two-layer topical composition, and may be 15% by mass or less, 10% by mass or less, 8% by mass or less, or 5% by mass or less. In particular, from the viewpoint of achieving the effects of the present invention, 0.1% by mass or more and 8% by mass or less is preferred, and 0.3% by mass or more and 5% by mass or less is more preferred. The content of component (A) as referred to here means the total amount of azelaic acid present in the powder layer and, if applicable, the amount of azelaic acid dissolved in the liquid layer.

[0016] The surfactant component (B) may be a nonionic surfactant, a cationic surfactant, an anionic surfactant, or an amphoteric surfactant, but from the viewpoint of further enhancing the effects of the present invention, a nonionic surfactant is preferred. Component (B) may also be a component having a polyoxyethylene chain from the viewpoint of further enhancing the effects of the present invention.

[0017] Nonionic surfactants are not particularly limited, but include polyoxyalkylene alkyl ethers such as POE-2-decyltetradecyl alcohol, POE-POP tetradecyl ether, polyoxyethylene oleyl ether, polyoxyethylene cetyl ether, and polyoxyethylene lauryl alcohol ether; sorbitan fatty acid esters such as sorbitan monostearate, sorbitan sesquistearate, sorbitan tristearate, and sorbitan monooleate; and POE(20) sorbitan monoisostearate. POE-sorbitan fatty acid esters such as POE(20) sorbitan nolaurate, POE(20) sorbitan monooleate, POE(20) sorbitan monostearate, POE(20) sorbitan monococonut oil fatty acid, and POE(80) sorbitan laurate; glycerin fatty acid esters such as glyceryl monostearate and glyceryl oleate; POE-glycerin fatty acid esters such as glyceryl polyoxyethylene stearate and glyceryl polyoxyethylene trioleate; POE-dihydrocholesterol esters POE-hydrogenated castor oils such as polyoxyethylene hydrogenated castor oil 40 (HCO-40), polyoxyethylene hydrogenated castor oil 50 (HCO-50), polyoxyethylene hydrogenated castor oil 60 (HCO-60), polyoxyethylene hydrogenated castor oil 80 (HCO-80); POE-castor oils such as POE(3) castor oil and POE(20) castor oil; POE-hydrogenated castor oil fatty acid esters such as POE-hydrogenated castor oil isostearate; POE-alkylaryl ethers; POE fatty acid esters such as polyoxyl stearate; POE(2 0) POE sterols and hydrogenated sterols such as phytosterol, POE(30) phytosterol, POE(25) phytostanol, POE(30) cholestanol; sucrose fatty acid esters such as sucrose palmitate, sucrose stearate, sucrose oleate, sucrose isostearate, sucrose linoleate, sucrose linolenic acid; polyethylene glycol fatty acid esters such as polyoxyethylene glycol monostearate and polyethylene glycol dioleate;Polymeric glycerol fatty acid esters such as alkyl polyglycoside, diglyceryl monostearate, diglyceryl monoisostearate, decaglyceryl monostearate, polyglyceryl monolaurate, decaglyceryl monooleate, decaglyceryl pentaoleate, hexaglyceryl polylinoleate; alkyl-modified silicone, emulsified silicone elastomer, etc. Among these, as the nonionic surfactant, a nonionic surfactant having a polyoxyethylene chain is preferred, and POE-hydrogenated castor oil or POE-sorbitan fatty acid ester is more preferred.;

[0018] (B) The HLB value of the component may be 8 or more, 9 or more, or 10 or more, and may be 19 or less, 18 or less, or 17.6 or less. (B) The HLB value of the component may be 10 to 18. In this specification, the HLB value of the (B) component means a value measured based on the Griffin method.

[0019] (B) The content of the component may be 0.001% by mass or more, 0.01% by mass or more, or 0.03% by mass or more, and may be 5% by mass or less, 3% by mass or less, or 1% by mass or less based on the total amount of the two-layer external composition.

[0020] (B) The mass ratio of the content of the component to the content of the (A) component (surfactant content / azelaic acid content) is preferably 0.005 or more, 0.007 or more, or 0.01 or more, and preferably 0.5 or less, 0.3 or less, or 0.1 or less from the viewpoint of further enhancing the effects of the present invention.

[0021] The two-layer external composition may further contain (C) a metal salt (hereinafter also referred to as the “(C) component”). By the two-layer external composition containing the (C) component, the height of the powder layer can be further increased, and the interface between the liquid layer and the powder layer can be made visually clearer, and the appearance can be made even more excellent.

[0022] (C) Component may include alkali metal salts such as sodium salts and potassium salts; alkaline earth metal salts such as calcium salts and magnesium salts; aluminum salts; zinc salts; iron salts, etc. From the viewpoint of further enhancing the effects of the present invention, (C) component is preferably one or more selected from aluminum salts, magnesium salts, calcium salts, potassium salts, and sodium salts.

[0023] (C) Component (C) is more preferably composed of two or more metal salts, from the viewpoint of further enhancing the effects of the present invention, and in this case, it is more preferably two or more selected from aluminum salts, magnesium salts, calcium salts, potassium salts, and sodium salts.

[0024] More specifically, component (C) includes aluminum salts such as chlorohydroxyaluminum; sodium salts such as sodium benzoate, sodium pyrosulfite, and sodium ethylenediaminetetraacetate; potassium salts such as potassium chloride, dipotassium glycyrrhizinate, and potassium ethylenediaminetetraacetate; magnesium salts such as magnesium L-ascorbyl phosphate; and zinc salts such as zinc paraphenolsulfonate. From the viewpoint of further enhancing the effects of the present invention, it is preferable that component (C) contains an aluminum salt, and more preferably that it contains chlorohydroxyaluminum. Even when component (C) contains two or more metal salts, it is preferable that one of them is an aluminum salt, and more preferably that it contains chlorohydroxyaluminum.

[0025] When component (C) contains two or more metal salts, possible combinations include aluminum salt and sodium salt, aluminum salt and magnesium salt, aluminum salt and potassium salt, aluminum salt and calcium salt, etc. More specifically, when component (C) contains two or more metal salts, it is preferable that it contains aluminum chlorohydrate and sodium benzoate, aluminum chlorohydrate and magnesium L-ascorbyl phosphate, aluminum chlorohydrate and potassium chloride, aluminum chlorohydrate and calcium chloride, or aluminum chlorohydrate and dipotassium glycyrrhizinate.

[0026] (C) The content of component (total amount if two or more metal salts are included) may be 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more, and may be 1% by mass or less, 0.7% by mass or less, or 0.5% by mass or less, based on the total amount of the two-layer external composition.

[0027] The mass ratio of the content of component (C) to the content of component (A) (content of metal salt / content of azelaic acid) is preferably 0 or more, 0.005 or more, or 0.01 or more, and also preferably 0.5 or less, 0.3 or less, or 0.2 or less, from the viewpoint of further enhancing the effects of the present invention.

[0028] The two-layer topical composition may further contain (D) a water-soluble polymer (hereinafter also referred to as "component (D)"). By containing component (D) in the two-layer topical composition, aggregation of azelaic acid in the composition can be suppressed, and the appearance can be further improved. Component (D) may be, for example, a water-soluble polymer that functions as a thickening agent to impart a thickening effect.

[0029] (D) Examples of component include anionic polymers, cationic polymers, and polysaccharides.

[0030] Examples of anionic polymers include carboxyvinyl polymers, acrylates / C10-30 alkyl acrylate crosspolymers, polyacrylamides, (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymers, (ammonium acryloyldimethyltaurate / vinylpyrrolidone) copolymers, ammonium polyacryloyldimethyltaurate, and sodium polyacryloyldimethyltaurate.

[0031] Examples of cationic polymers include xanthan hydroxypropyltrimonium chloride, cationized hyaluronic acid, polyquaternium-67, cationized starch, and other cationized polysaccharides; and dimethyldiallylammonium chloride / acrylamide copolymer (polyquaternium-7). Among these, from the viewpoint of further enhancing the effects of the present invention, cationized polysaccharides are preferred, cationized xanthan gum is more preferred, and xanthan hydroxypropyltrimonium chloride is even more preferred.

[0032] Examples of polysaccharides include cellulose derivatives such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, carboxyethylcellulose, nitrocellulose, or salts thereof; pullulan; guar gum; pectin; gelatin; locust bean gum; carrageenan; agar; and gellan gum.

[0033] Component (D) preferably comprises one or more selected from anionic polymers, cationic polymers, cellulose derivatives, and pullulan, from the viewpoint of further enhancing the effects of the present invention. Component (D) more preferably comprises cationized xanthan gum and / or hydroxyethylcellulose, and even more preferably comprises hydroxyethylcellulose, from the viewpoint of further enhancing the effects of the present invention.

[0034] The content of component (D) may be 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more, and may be 0.5% by mass or less, 0.4% by mass or less, or 0.3% by mass or less, based on the total amount of the two-layer topical composition.

[0035] The two-layer topical composition may further contain (E) water (hereinafter also referred to as "(E) component"). Examples of (E) component include distilled water, purified water, hot spring water, deep sea water, etc.

[0036] (E) The content of component (E) is preferably 60% by mass or more, based on the total amount of the two-layer topical composition, from the viewpoint of easily obtaining a refreshing and moist feeling when using the two-layer topical composition. The content of component (E) may be 65% by mass or more, 70% by mass or more, or 75% by mass or more, and may be 99% by mass or less, 98% by mass or less, or 95% by mass or less, based on the total amount of the two-layer topical composition.

[0037] The two-layer topical composition may further contain (F) polyhydric alcohol (hereinafter also referred to as "(F) component"). Component (F) functions as a moisturizing ingredient in the two-layer topical composition, for example. Examples of (F) component include polyethylene glycol, 1,3-butylene glycol, pentylene glycol, propanediol, glycerin, diglycerin, and trehalose.

[0038] (F) When polyethylene glycol is used as component, the number average molecular weight is preferably 100 to 650, preferably 150 to 600, and more preferably 180 to 420. The number average molecular weight of polyethylene glycol in this specification is a converted value based on the standard polystyrene calibration curve, measured by gel permeation chromatography (GPC).

[0039] (F) The content of component (F) is preferably 30% by mass or less based on the total amount of the two-layer topical composition, from the viewpoint of easily obtaining a refreshing and moist feeling when using the two-layer topical composition. The content of component (F) may be 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less based on the total amount of the two-layer topical composition, and may be 0.5% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more.

[0040] The two-layer topical composition of the present invention may contain a small amount of oil. If the two-layer topical composition contains oil, the amount is preferably 1% by mass or less based on the total amount of the two-layer topical composition. The oil content may be 0.5% by mass or less, or 0.1% by mass or less, based on the total amount of the two-layer topical composition. The two-layer topical composition does not need to contain oil.

[0041] The pH of the two-layer topical composition may be 2.0 or higher, 2.5 or higher, or 3.0 or higher. Furthermore, from the viewpoint of making it difficult to dissolve azelaic acid in the liquid layer, the pH of the two-layer topical composition is preferably 6.0 or lower, 5.8 or lower, 5.2 or lower, or 4.8 or lower. The pH of the two-layer topical composition is preferably 2.0 to 6.0, more preferably 2.5 to 5.2, and even more preferably 3.0 to 4.8.

[0042] In a two-layer topical composition, the lightness (L* value) of the liquid layer is preferably 85 or higher, more preferably 90 or higher, and even more preferably 95 or higher, from the viewpoint of further enhancing the effects of the present invention. There is no particular upper limit to the lightness (L* value) of the liquid layer; it may be 100 or less. The lightness (L* value) in this specification is a value based on the Lab color space specified in JIS Z 8781-4, and is measured using a spectrophotometer (CM-5, Konica Minolta) with purified water as a blank after the two-layer topical composition has been allowed to stand for 24 hours. When purified water is used as the blank, the closer the L* value is to 100, the more transparent it is.

[0043] From the viewpoint of further enhancing the effects of the present invention, the brightness (L* value) of the powder layer in the two-layer external composition is preferably 85 or less, more preferably 82 or less, and even more preferably 78 or less. The lower limit of the brightness (L* value) of the powder layer is not particularly limited, but may be, for example, 30 or more.

[0044] In a two-layer external composition, the difference ΔL (L* value of the liquid layer - L* value of the powder layer) between the L* value of the liquid layer and the L* value of the powder layer is preferably 10 or more, more preferably 15 or more, and even more preferably 20 or more, from the viewpoint of further enhancing the effects of the present invention. The upper limit of ΔL is not particularly limited, but may be, for example, 60 or less.

[0045] From the viewpoint of further enhancing the effects of the present invention, the turbidity of the liquid layer in the two-layer topical composition is preferably 300 degrees or less, more preferably 100 degrees or less, and even more preferably 50 degrees or less. The lower limit of the turbidity of the liquid layer is not particularly limited, but for example, it is 20 degrees or more, or 30 degrees or more. The turbidity of the liquid layer according to this embodiment is measured by taking a sample of the liquid layer after the two-layer topical composition has been allowed to stand for 17 hours, and using a turbidimeter (digital turbidimeter 500G, manufactured by Kyoritsu Chemical Research Institute Co., Ltd.).

[0046] In this embodiment, the two-layer external composition preferably has a large proportion of the height of the powder layer relative to the total height of the composition, from the viewpoint of visually clearly forming the powder layer and the liquid layer. The ratio of the height of the powder layer to the total height of the composition (height of powder layer / total height of composition) is preferably greater than 0.020, more preferably greater than 0.050, even more preferably greater than 0.120, and particularly preferably greater than 0.180. The ratio of the height of the powder layer to the total height of the composition may be, for example, 0.800 or less, or 0.700 or less.

[0047] The two-layer topical composition of this embodiment may be a pharmaceutical, a quasi-drug, or a cosmetic. Preferably, the two-layer topical composition of this embodiment is a two-layer topical skin composition applied to the skin.

[0048] The form of a two-layer topical composition used for pharmaceutical purposes is not particularly limited, and examples include liquids, suspensions, emulsions, creams, ointments, gels, liniments, lotions, and aerosols. These preparations can be manufactured according to the methods described in the General Provisions of the 18th Revised Japanese Pharmacopoeia. Among the forms of two-layer topical compositions used for pharmaceutical purposes, liquids, suspensions, and lotions are preferred.

[0049] When used as a two-layer topical composition for quasi-drugs or cosmetics, it can take the same form as the two-layer topical composition for pharmaceuticals described above. Among the forms of topical preparations used as quasi-drugs or cosmetics, liquids, suspensions, and lotions are preferred.

[0050] When used as a two-layer external composition for quasi-drugs or cosmetics, examples of its uses include basic cosmetics such as lotions, emulsions, gels, creams, serums, sunscreens, hand creams, body lotions, and body creams; and cleansing cosmetics such as facial cleansers, makeup removers, shaving agents, body washes, shampoos, conditioners, and treatments. Among these uses, lotions, serums, and body lotions are particularly preferred when used as a two-layer external composition for quasi-drugs or cosmetics. When used as a cosmetic, the two-layer external composition may also be called "powder cosmetic" or "powder lotion."

[0051] The two-layer topical composition of this embodiment may contain other ingredients that are commonly used in pharmaceuticals, quasi-drugs, or cosmetics, as long as they do not impair the effects of the present invention. Examples of such ingredients include other active ingredients or ingredients equivalent to additives.

[0052] Other active ingredients include, for example, moisturizing ingredients, anti-inflammatory ingredients, antibacterial ingredients, vitamins, peptides or their derivatives, amino acids or their derivatives, cell-activating ingredients, anti-aging ingredients, blood circulation promoting ingredients, keratin softening ingredients, whitening ingredients, astringent ingredients, etc.

[0053] Moisturizing ingredients include high molecular weight compounds such as sodium hyaluronate, heparinoid, sodium chondroitin sulfate, collagen, elastin, keratin, chitin, and chitosan; amino acids such as glycine, aspartic acid, and arginine; natural moisturizing factors such as sodium lactate, urea, and sodium pyrrolidone carboxylate; lipids such as ceramide, cholesterol, and phospholipids; and plant extracts such as chamomile extract, witch hazel extract, tea extract, and perilla extract.

[0054] Examples of anti-inflammatory ingredients include plant-derived components (such as comfrey), allantoin, glycyrrhetinic acid, glycyrrhizic acid or their derivatives, pyridoxine hydrochloride, tocopherol acetate, salicylic acid or its derivatives, and ε-aminocaproic acid.

[0055] Examples of antibacterial or bactericidal ingredients include chlorhexidine, salicylic acid, benzalkonium chloride, acrinol, sulfur, resorcinol, ethanol, benzethonium chloride, adapalene, benzoyl peroxide, clindamycin, cresol, gluconic acid and its derivatives, povidone-iodine, iodine, isopropylmethylphenol, triclocarban, triclosan, photosensitizer 101, photosensitizer 201, parabens, phenoxyethanol, 1,2-pentanediol, alkyldiaminoglycine hydrochloride, and chlorhexidine gluconate.

[0056] Vitamins include retinol derivatives such as retinol, retinyl acetate, and retinyl palmitate; vitamin A derivatives such as retinal, retinoic acid, methyl retinoate, ethyl retinoate, retinyl retinoate, d-δ-tocopheryl retinoate, α-tocopheryl retinoate, and β-tocopheryl retinoate; vitamin E derivatives such as dl-α-tocopherol, dl-α-tocopherol acetate, and dl-α-tocopherol succinate; riboflavin, flavin mononucleotide, flavin adenine dinucleotide, and riboflavin nucleotide. Vitamin B2 compounds such as acid esters, riboflavin tetrabutyrate, and riboflavin tetranicotinate; nicotinic acids such as dl-α-tocopherol nicotinate, benzyl nicotinate, methyl nicotinate, β-butoxyethyl nicotinate, and 1-(4-methylphenyl)ethyl nicotinate; vitamin C compounds such as ascorbigen-A, ascorbic acid stearate, ascorbic acid palmitate, and L-ascorbyl dipalmitate; and vitamins such as methyl hesperidin, ergocalciferol, and cholecalciferol. Vitamin D; Vitamin K compounds such as phylloquinone and farnoquinone, γ-oryzanol, dibenzoylthiamine, dibenzoylthiamine hydrochloride; thiamine hydrochloride, thiamine cetyl hydrochloride, thiamine thiocyanate, thiamine lauryl hydrochloride, thiamine nitrate, thiamine monophosphate, thiamine lysine salt, thiamine triphosphate, thiamine monophosphate phosphate, thiamine monophosphate, thiamine diphosphate, thiamine diphosphate hydrochloride, thiamine triphosphate, thiamine triphosphate monophosphate, and other vitamins. Vitamin B1s; Vitamin B6s such as pyridoxine hydrochloride, pyridoxine acetate, pyridoxal hydrochloride, pyridoxal 5'-phosphate, and pyridoxamine hydrochloride; Vitamin B12s such as cyanocobalamin, hydroxocobalamin, and deoxyadenosylcobalamin; Folic acid derivatives such as folic acid and pteroylglutamic acid; Nicotinic acid derivatives such as nicotinic acid and nicotinamide; Pantothenic acid derivatives such as pantothenic acid, pantothenyl alcohol (panthenol), D-panthesine, D-pantethine, coenzyme A, and pantothenyl ethyl ether; Biotin derivatives such as biotin and biotisine;Examples include vitamin C derivatives such as ascorbic acid, sodium ascorbate, and dehydroascorbic acid; and vitamin-like factors such as carnitine, ferulic acid, alpha-lipoic acid, and orotic acid.

[0057] Examples of peptides or their derivatives include keratin-degrading peptides, hydrolyzed keratin, collagen, fish-derived collagen, atelocollagen, gelatin, elastin, elastin-degrading peptides, collagen-degrading peptides, hydrolyzed collagen, hydroxypropylammonium chloride hydrolyzed collagen, elastin-degrading peptides, conchiolin-degrading peptides, hydrolyzed conchiolin, silk protein-degrading peptides, hydrolyzed silk, sodium lauroyl hydrolyzed silk, soy protein-degrading peptides, hydrolyzed soy protein, wheat protein, wheat protein-degrading peptides, hydrolyzed wheat protein, casein-degrading peptides, and acylated peptides (such as palmitoyl oligopeptides, palmitoyl pentapeptides, and palmitoyl tetrapeptides).

[0058] Examples of amino acids or their derivatives include betaine (trimethylglycine), proline, hydroxyproline, arginine, lysine, serine, glycine, alanine, phenylalanine, β-alanine, threonine, glutamic acid, glutamine, asparagine, aspartic acid, cysteine, cystine, methionine, leucine, isoleucine, valine, histidine, taurine, γ-aminobutyric acid, γ-amino-β-hydroxybutyric acid, carnitine, carnosine, and creatine.

[0059] Cell-activating components include amino acids such as γ-aminobutyric acid and ε-aminocaproic acid; vitamins such as retinol, thiamine, riboflavin, pyridoxine hydrochloride, and pantothenic acids; α-hydroxy acids such as glycolic acid and lactic acid; and tannins, flavonoids, saponins, allantoin, and photosensitizer 301.

[0060] Anti-aging ingredients include pangamic acid, kinetin, ursolic acid, turmeric extract, sphingosine derivatives, silicon, silicic acid, N-methyl-L-serine, and mevalonolactone.

[0061] Ingredients that promote blood circulation include those derived from plants (such as ginseng, angelica tree, arnica, ginkgo, fennel, watercress, watercress, chamomile, Roman chamomile, carrot, gentian, burdock, rice, hawthorn, shiitake mushroom, European hawthorn, European juniper, cinnamon, gentian, thyme, clove, dried tangerine peel, angelica, peach kernel, spruce, carrot, garlic, butcher's broom, grape, peony, horse chestnut, lemon balm, yuzu, coix seed, rosemary, rosehip, dried tangerine peel, angelica, spruce, peach, apricot, walnut, corn, etc.); glucosyl hesperidin is one example.

[0062] Examples of keratin-softening ingredients include urea, salicylic acid, glycolic acid, fruit acids, phytic acid, and sulfur.

[0063] Examples of skin-whitening ingredients include ascorbic acid and its derivatives, arbutin, and tocopherol.

[0064] Astringent ingredients include menthol and ethanol.

[0065] Additives include, for example, antioxidants, preservatives, pH adjusters, stabilizers, irritation reducers, colorants, fragrances, and pearlescent finish enhancers.

[0066] Examples of antioxidants include dibutylhydroxytoluene, butylhydroxyanisole, sorbic acid, ascorbic acid, ascorbic acid derivatives, tocopherol, tocopherol derivatives, erythorbic acid, and L-cysteine ​​hydrochloride.

[0067] Examples of preservatives include benzoic acid, dehydroacetic acid, sodium dehydroacetate, isobutyl parahydroxybenzoate, isopropyl parahydroxybenzoate, butyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, benzyl parahydroxybenzoate, methyl parahydroxybenzoate, phenoxyethanol, benzyl alcohol, chlorobutanol, sorbic acid and its salts, chlorhexidine gluconate, and alkanediols.

[0068] Examples of pH adjusters include inorganic acids (hydrochloric acid, sulfuric acid, etc.), organic acids (lactic acid, sodium lactate, citric acid, sodium citrate, succinic acid, etc.), and organic bases (triethanolamine, diisopropanolamine, triisopropanolamine, etc.).

[0069] Examples of stabilizers include dibutylhydroxytoluene and butylhydroxyanisole. Examples of irritation-reducing agents include licorice extract.

[0070] The method of using the two-layer topical composition of this embodiment varies depending on the skin condition, age, and gender of the user, but it is sufficient to apply an appropriate amount to the skin several times a day. For example, the two-layer topical composition can be shaken immediately before use to disperse the azelaic acid and homogenize the composition before application. Because the two-layer topical composition of this embodiment contains azelaic acid, it can also be used for the prevention or treatment of acne. Therefore, in addition to healthy individuals, people with acne are suitable users. [Examples]

[0071] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0072] In the following test examples, the details of the surfactants used and their HLB values ​​(measured values) are as follows. Polyoxyethylene sorbitan monolaurate (20E.O.): Product name "Nonion LT-20", manufactured by NOF Corporation, HLB 16.7 Polyoxyethylene hydrogenated castor oil 40: Product name "NIKKOL HCO-40", manufactured by Nikko Chemicals Co., Ltd., HLB 12.5 Polyoxyethylene hydrogenated castor oil 60: Product name "NIKKOL HCO-60", manufactured by Nikko Chemicals Co., Ltd., HLB 14.0 Polyoxyethylene hydrogenated castor oil 80: Product name "NIKKOL HCO-80", manufactured by Nikko Chemicals Co., Ltd., HLB 15.0 Polysorbate 60: Product name "NIKKOL TS-10MV", manufactured by Nikko Chemicals Co., Ltd., HLB 15.0 Polysorbate 80: Product name "NIKKOL TO-10MV", manufactured by Nikko Chemicals Co., Ltd., HLB 15.0 Polyoxyethylene sorbitan isostearate (20E.O.): Product name "NIKKOL TI-10V", manufactured by Nikko Chemicals Co., Ltd., HLB 15.0 Polyoxyethylene polyoxypropylene decyltetradecyl ether (PPG-6 decyltetradeceth-30): Product name "Solbure GS-01", manufactured by NOF Corporation, HLB 10.0 Polyethylene glycol monostearate: Product name "NIKKOL MYS-40MV", manufactured by Nikko Chemicals Co., Ltd., HLB 17.5 Polyglyceryl(-10) monolaurate: Product name "Sunsoft Q-12Y-C", manufactured by Taiyo Kagaku Co., Ltd., HLB 17.1 Polyglyceryl monooleate (-10): Product name "Sunsoft Q-17Y-C", manufactured by Taiyo Kagaku Co., Ltd., HLB 15.9 Lauromacrogol: Product name "NIKKOL BL-9EX", manufactured by Nikko Chemicals Co., Ltd., HLB 14.5

[0073] <Test Example 1: Azelaic Acid Precipitation Confirmation Test> All the materials shown in Tables 1 to 3 were placed in 100 mL glass bottles (Vials With Screw Cap / SV-100, manufactured by Nippon Rika Glass Co., Ltd.), and then shaken using a shaker (Iwaki KM type universal shaker V-DX, manufactured by Iwaki Sangyo Co., Ltd.) at a speed of 100 for 1 minute to obtain the formulations (external compositions) for the comparative example and the example. The total volume of each formulation was prepared to be 50 g.

[0074] After allowing the prepared formulation to stand for 17 hours, the presence or absence of a powder layer formation due to azelaic acid sedimentation was visually determined based on the following criteria. ○: A liquid layer is formed as the upper layer, and a powder layer of azelaic acid is formed as the lower layer, and no azelaic acid powder is observed in the liquid layer. ×: Either the liquid layer and powder layer are not formed and the two layers are not separated, or even if the liquid layer and powder layer are formed, azelaic acid powder is suspended in the liquid layer.

[0075] The evaluation results are shown in Tables 1 to 3. Furthermore, Figure 1 shows the appearance after standing for Comparative Example 2 and Example 2. As shown in Tables 1 to 3 and Figure 1, the formulations containing azelaic acid and surfactant formed two layers: a liquid layer and a powder layer. The boundaries between the layers were clearly formed without azelaic acid floating in the liquid layer.

[0076] [Table 1]

[0077] [Table 2]

[0078] [Table 3]

[0079] <Test Example 2: Visual Evaluation Test> Using the materials shown in Tables 4 to 6, formulations (topical compositions) according to the examples were obtained in the same manner as in Test Example 1. After allowing the prepared formulations to stand for 17 hours, two layers, a powder layer and a liquid layer, were formed in all examples 12, 13, and 21-34. The height of the formed powder layer and the height of the entire formulation were measured with a ruler, and (height of powder layer) / (height of entire formulation) was calculated and used as the evaluation value for the height of the powder layer. The larger this evaluation value, the higher the apparent height of the powder, and the more clearly the powder layer and liquid layer are formed, which is considered more preferable in terms of appearance.

[0080] Furthermore, for each composition after standing, 10 mL of the liquid layer was taken from approximately 1 cm above the liquid surface, and the turbidity was measured using a turbidimeter (digital turbidimeter 500G, manufactured by Kyoritsu Chemical Research Institute Co., Ltd.). The lower the turbidity of the liquid layer, the clearer the boundary between the powder layer and the liquid layer is formed, which is considered more preferable in terms of appearance.

[0081] The evaluation values ​​and turbidity of the liquid layer are shown in Tables 4 to 6. Furthermore, the height, turbidity, and overall appearance of the powder layer were evaluated based on the following criteria. [Judgment criteria] Powder layer height / Total formulation height: S: Greater than 0.180, A: Greater than 0.120 and 0.180 or less, B: Greater than 0.050 and 0.120 or less, C: 0.050 or less Turbidity: S: 50 degrees or less, A: greater than 50 degrees and 100 degrees or less, B: greater than 100 degrees and 300 degrees or less, C: greater than 300 degrees Overall evaluation of appearance: S: Excellent, A: Good, B: Fair, C: Average

[0082] The formulations of Examples 12 and 13, which did not contain metal salts, formed two layers, a liquid layer and a powder layer, and had an excellent appearance as a two-layer topical composition. However, the formulations of Examples 21 to 34, which further contained metal salts, had a higher powder layer, resulting in an even better appearance as a two-layer topical composition. In addition, in Examples 21 to 34, the turbidity of the liquid layer was further reduced, and the boundary between the liquid layer and the powder layer was more clearly formed.

[0083] [Table 4]

[0084] [Table 5]

[0085] [Table 6]

[0086] <Test Example 3: Aggregation Confirmation Test> Of the materials shown in Table 7, (B) surfactant, (D) water-soluble polymer, and (E) purified water were placed in a 100 mL glass bottle (Vials With Screw Cap / SV-100, manufactured by Nippon Rika Glass Co., Ltd.) and stirred with a stirrer while heating at 70°C. After heating and stirring, the mixture was cooled to 35°C, the remaining materials were added, and the mixture was shaken using a shaker at a speed of 100 for 1 minute to obtain the formulations (external compositions) according to Examples 35 to 41. The total amount of each formulation was prepared to be 50 g.

[0087] After allowing the prepared formulations to stand for 24 hours, two layers, a powder layer and a liquid layer, were formed in all of Examples 35 to 41. Of these, the L* values ​​of the liquid layer and powder layer were measured for the formulation of Example 36. Specifically, after allowing the formulations to stand, the liquid layer and powder layer were sampled, and the L* values ​​were measured using a colorimetric spectrometer (CM-5, manufactured by Konica Minolta, Inc.) that had been pre-blanked with water. As a result, the L* value of the liquid layer was 97, the L* value of the powder layer was 76.11, and the ΔL (L* value of the liquid layer - L* value of the powder layer) was 20.89.

[0088] Furthermore, for the formulations of Examples 35 to 41, the presence or absence of azelaic acid aggregation in the powder layer after 24 hours of standing was visually confirmed. The results are shown in Table 7. The appearance of Examples 36 to 41 after standing is shown in Figure 2. As shown in Table 7, no aggregation of azelaic acid was observed in any of the examples. Also, as shown in Figure 2, the appearance after standing was excellent in all examples, and in particular, Example 36 had the finest powder particles in appearance, and the boundary between the powder layer and the liquid layer was flat.

[0089] [Table 7]

Claims

1. A two-layer topical composition containing (A) azelaic acid and (B) a surfactant.

2. (C) The two-layer topical composition according to claim 1, further containing a metal salt.

3. The two-layer external composition according to claim 2, wherein the (C) component is one or more selected from aluminum salts, magnesium salts, calcium salts, potassium salts, and sodium salts.

4. The two-layer topical composition according to claim 2 or 3, wherein the (C) component comprises two or more metal salts.

5. The two-layer topical composition according to claim 2 or 3, wherein component (C) contains chlorohydroxyaluminum.

6. (D) A two-layer external composition according to any one of claims 1 to 3, further comprising a water-soluble polymer.

7. The two-layer topical composition according to claim 6, wherein the component (D) is one or more selected from anionic polymers, cationic polymers, cellulose derivatives, and pullulan.

8. The two-layer topical composition according to claim 6, wherein component (D) comprises hydroxyethylcellulose.

9. The two-layer topical composition according to any one of claims 1 to 3, wherein the pH of the two-layer topical composition is 2.0 to 6.

0.

10. The two-layer topical composition according to any one of claims 1 to 3, wherein the HLB value of component (B) is 8 to 19.

11. The two-layer topical composition according to any one of claims 1 to 3, further comprising (E) water, wherein the content of component (E) is 60% by mass or more based on the total amount of the two-layer topical composition.

12. (F) A two-layer topical composition according to any one of claims 1 to 3, further containing a polyhydric alcohol, wherein the content of component (F) is 30% by mass or less based on the total amount of the two-layer topical composition.

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