Crystallization inhibitors for ceramides and ceramide analogues

Abstract

To provide a crystallization inhibitor for inhibiting ceramide deposition at low and high temperatures in a topical skin preparation.SOLUTION: A crystallization inhibitor comprises (A) a polyglycerol fatty acid ester comprising a polyglycerol with an average degree of polymerization of 6-20 and a C8-22 branched fatty acid and (B) a polyglycerol fatty acid ester comprising a polyglycerol with an average degree of polymerization of 6-20 and a C8-14 linear fatty acid, with the mass ratio being (A) / (B)=50 / 50-100 / 0.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a crystallization inhibitor for ceramide or ceramide analogues, and an external skin preparation containing the same. [Background technology]

[0002] Ceramides are substances present in the intercellular lipids that form the stratum corneum of the skin, and approximately 50% of these intercellular lipids are composed of ceramides. Ceramides prevent water evaporation by forming a lipid barrier necessary for moisture retention, enhancing the skin's ability to retain moisture. However, a decrease in ceramide content is known to reduce the barrier function and moisturizing function. Therefore, attempts have been made to prepare cosmetics containing ceramides with the aim of replenishing ceramides in the stratum corneum and enhancing the skin's ability to retain moisture. However, ceramides are highly crystalline and have low solubility in cosmetic bases (especially water). It is important for cosmetics to maintain their appearance over time, and ensuring stability over time has been difficult for cosmetics containing ceramides, which crystallize at low or high temperatures.

[0003] For example, Patent Document 1 discloses a method using a specific polyoxyalkylene glyceryl monoalkyl ester to transparently disperse ceramides in water. While the stability of the transparent dispersion produced by this method is described at room temperature, there is no mention of its stability at low temperatures, where ceramides are more likely to precipitate. Furthermore, Patent Document 2 discloses a lotion formulated with a nonionic surfactant for the purpose of stably solubilizing ceramides. While there is a description of the stability of this lotion at 40°C, like Patent Document 1, there is no mention of its stability at low temperatures. Because topical preparations such as cosmetics and pharmaceuticals require stability at both high and low temperatures, there has been a need for a method to inhibit ceramide crystallization at both high and low temperatures. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-139796 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-148473 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a crystallization inhibitor that inhibits the precipitation of ceramides at low and high temperatures in external skin preparations. [Means for solving the problem]

[0006] As a result of intensive research to solve the above problems, the present inventors discovered that the use of a specific polyglycerol fatty acid ester can suppress the crystallization of ceramide at low and high temperatures, and thus completed the present invention.

[0007] That is, the present invention provides a crystallization inhibitor for ceramides, in which the mass ratio of (A) a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization of 6 to 20 and a branched fatty acid having 8 to 22 carbon atoms and (B) a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization of 6 to 20 and a linear fatty acid having 8 to 14 carbon atoms is (A) / (B) = 50 / 50 to 100 / 0. [Effects of the Invention]

[0008] The present invention can provide a crystallization inhibitor that can inhibit the crystallization of ceramides at high and low temperatures by using a specific polyglycerol fatty acid ester. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. The scope of the present invention is not limited to the embodiments, and the present invention also includes modifications made within the scope of the present invention. Note that the range "to" includes the upper and lower limits.

[0010] The present invention comprises (A) a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization of 6 to 20 and a branched fatty acid having 8 to 22 carbon atoms, and (B) a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization of 6 to 20 and a linear fatty acid having 8 to 14 carbon atoms.

[0011] The method for producing polyglycerol, which is the raw material for polyglycerol fatty acid esters, is not particularly limited, but examples thereof include a conventional method for producing polyglycerol, in which glycerol is heated in the presence of an alkali catalyst under normal or reduced pressure.

[0012] The average degree of polymerization of polyglycerol is calculated from the hydroxyl value using the following formula (i): The hydroxyl value in formula (i) is measured in accordance with the "Standard Methods for the Analysis of Fats, Oils and Related Materials, 2013 Edition" (established by the Japan Oil Chemists' Society). Average degree of polymerization = (112220 - 18 x hydroxyl value) / (74 x hydroxyl value - 56110) (i)

[0013] The hydroxyl value of the polyglycerol in the present invention may be calculated from the polyglycerol as a raw material, or may be calculated from the polyglycerol obtained by saponifying and decomposing the polyglycerol fatty acid ester of the present invention.

[0014] The esterification rate of the polyglycerol fatty acid ester in the present invention is a value calculated by the following formula (ii) when the average degree of polymerization of the polyglycerol (n) calculated from the hydroxyl value, the number of hydroxyl groups in the polyglycerol (n+2), and the number of moles of fatty acid added to 1 mole of the polyglycerol (M) are used: Esterification rate (%) = (M / (n+2)) × 100 (ii)

[0015] The hydroxyl value of the polyglycerin used in the polyglycerin fatty acid ester of component (A) is preferably 800 to 980, more preferably 800 to 870, from the viewpoint of transparency of the topical skin preparation. The constituent fatty acids are branched fatty acids having 8 to 22 carbon atoms, and specific examples thereof include 2-ethylhexanoic acid, isononanoic acid, isopalmitic acid, isostearic acid, and isobehenic acid. The esterification rate of component (A) is preferably 8 to 20%. Specific examples of component (A) include polyglyceryl-6 isostearate and polyglyceryl-10 isostearate, with polyglyceryl-10 monoisostearate being preferred.

[0016] Commercially available products can also be used as component (A), such as IS-601P, IS-1001P, and 10G-IS manufactured by Sakamoto Pharmaceutical Co., Ltd.

[0017] The hydroxyl value of the polyglycerin used in the polyglycerin fatty acid ester of component (B) is preferably 800 to 980, more preferably 800 to 870, from the viewpoint of the transparency of the topical skin preparation. The constituent fatty acids are straight-chain fatty acids having 8 to 14 carbon atoms, specifically caprylic acid, capric acid, lauric acid, myristic acid, etc., with lauric acid being preferred from the viewpoint of the transparency and low-temperature stability of the topical skin preparation. The esterification rate of component (B) is preferably 8 to 20%. Specific examples of component (B) include polyglyceryl-10 caprylate, polyglyceryl-6 laurate, polyglyceryl-10 laurate, polyglyceryl-6 myristate, and polyglyceryl-10 myristate. Of these, polyglyceryl-10 monolaurate is preferred.

[0018] Commercially available products can also be used as component (B), such as MCA-750, ML-500, ML-750, 10G-L, and M-1001 manufactured by Sakamoto Pharmaceutical Co., Ltd.

[0019] The mass ratio ((A) / (B)) of the component (A) to the component (B) used in the present invention is 50 / 50 to 100 / 0, and preferably 50 / 50 to 70 / 30.

[0020] Component (C) used in the present invention is ceramide or a ceramide analogue, such as ceramide-1, ceramide-2, ceramide-3, di(phytosteryl 2-octyldodecyl) N-lauroyl-L-glutamate, or polyquaternium 51. Of these, ceramide-3 is preferred.

[0021] The component (D) used in the present invention is an alkanediol. Specific examples include propanediol, butanediol, pentanediol, hexanediol, etc. Of these, hexanediol is preferred, and 1,2-hexanediol is more preferred.

[0022] Furthermore, the composition may contain ingredients commonly used in external preparations within the scope of the present invention, such as hydrocarbons such as liquid paraffin, liquid isoparaffin, petrolatum, squalane, paraffin, pristane, α-olefin oligomer, ceresin, microcrystalline wax, and polyethylene, avocado oil, linseed oil, almond oil, olive oil, cacao butter, carrot oil, cucumber oil, kukui nut oil, grapeseed oil, sesame oil, wheat germ oil, rice bran oil, safflower oil, shea butter, soybean oil, tea oil, evening primrose oil, camellia oil, corn oil, rapeseed oil, persic oil, Job's tears oil, palm oil, palm kernel oil, castor oil, and hydrogenated castor oil. Examples of suitable oils include vegetable oils such as sunflower oil, hazelnut oil, macadamia nut oil, meadowfoam oil, cottonseed oil, Japan wax oil, coconut oil, peanut oil, rosehip oil, camellia oil, sasanqua oil, rapeseed oil, Job's tears oil, jojoba oil, hydrogenated jojoba oil, hardened coconut oil, clove oil, lavender oil, rosemary oil, turpentine, and eucalyptus oil; animal oils such as orange roughy oil, beef tallow, horse oil, turtle oil, mink oil, egg yolk oil, and lanolin; beeswax, whale wax, carnauba wax, candelilla wax, montan wax, rice wax, lanolin wax, and shellac. Examples of hydrocarbon waxes include waxes such as solid paraffin, ceresin, ozokerite, ethylene-propylene copolymer, polyethylene wax, Fischer-Tropsch wax, Ibota wax, and Rhododendron obovata; arachidonic acid, isostearic acid, undecylenic acid, erucic acid, oleic acid, stearic acid, sebacic acid, palmitic acid, behenic acid, myristic acid, lauric acid, lanolin fatty acid, linoleic acid, linolenic acid, capric acid, caprylic acid, hydroxystearic acid, safflower oil fatty acid; Fatty acids such as menka fatty acids, tall oil fatty acids, and coconut fatty acids, isostearyl alcohol, oleyl alcohol, octyldodecanol, octyl alcohol, decyl alcohol, arachyl alcohol, hexyldecanol, chimyl alcohol, β-glucan, cholesterol, sitosterol, dihydrocholesterol, stearyl alcohol, cetyl alcohol, cetanol, cetostearyl alcohol, selachyl alcohol, batyl alcohol, phytosterol, hexyldecanol, behenyl alcohol, lauryl alcohol,Higher alcohols such as lanolin alcohol and myristyl alcohol, avocado oil fatty acid ethyl, dioctyl adipate, diisopropyl adipate, diisobutyl adipate, di-2-hexyldecyl adipate, diheptylundecyl adipate, lanolin acetate, alkyl benzoate, hexyldecyl isostearate, isopropyl isostearate, octyldodecyl isostearate, isocetyl isostearate, isostearyl isostearate, glyceryl isostearate, cholesteryl isostearate, batyl isostearate, isostearate Phytosteryl acrylate, alkyl octanoate, ethylene glycol fatty acid ester, octyldodecyl erucate, pentaerythrityl octanoate, cetyl octanoate, isocetyl octanoate, cetearyl octanoate, stearyl octanoate, isostearyl octanoate, ethyl oleate, oleyl oleate, ethylene glycol dioleate, glyceryl trioleate, octyldodecyl oleate, decyl oleate, cetyl caprate, cetyl caprylate, glyceryl tricaprylate, cetyl ethylhexanoate, octyldodecyl erucate, Cetostearyl tetrhexanoate, propylene glycol dicaprylate, neopentyl glycol dicaprate, neopentyl glycol dioctanoate, ethylene glycol dioctanoate, propylene glycol dicaprate, diglycerin isopalmitate sebacic acid condensate, glycol distearate, dipentaerythrityl (hydroxystearate / isostearate), hexyldecyl neodecanoate, hexyldecyl stearate, cholesteryl stearate, isocetyl stearate, stearyl stearate, batyl stearate, stearate Butyl tearic acid, cetyl isooctanate, diisopropyl sebacate, diethyl sebacate, diisopropyl dimerate, dialkyl carbonate, hydroxy fatty acid cholesteryl, pentaerythrityl isostearate, pentaerythrityl tetraoctanoate, glyceryl triisostearate, diglyceryl diisostearate, diglyceryl triisostearate, diglyceryl tetraisostearate, decaglyceryl nonaisostearate, decaglyceryl decaisostearate, trimethylolpropane triisostearate, trioctanoin,Trimethylolpropane trioctanoate, hexyldecyl dimethyloctanoate, octyldodecyl dimethyloctanoate, isononyl isononanoate, isodecyl isononanoate, tridecyl isononanoate, propylene glycol dipelargonate, octyl pelargonate, octyl isopelargonate, caprylic / capric triglyceride, glyceryl trimyristate, cetyl lactate, myristyl lactate, lauryl lactate, octyldodecyl lactate, isostearyl palmitate, isopropyl palmitate, octyl palmitate, cetyl palmitate , Isocetyl Palmitate, Octyl Isopalmitate, Cholesteryl Hydroxystearate, 2-Ethylhexyl Hydroxystearate, Isotridecyl Myristate, Isocetyl Myristate, Isostearyl Myristate, Isopropyl Myristate, Octyldodecyl Myristate, Myristyl Myristate, Hexyl Laurate, Isostearyl Laurate, Isopropyl Lanolinate, Cholesteryl Lanolinate, Tocopheryl Linoleate, Octyldodecyl Ricinoleate, Diisostearyl Malate, Polypropylene Succinate Ester oils such as pyrene glycol oligoester, di-2-ethylhexyl succinate, stearyl heptanoate, etc., silicone film-forming agents such as methylpolysiloxane, dimethylpolysiloxane, methylphenylpolysiloxane, trimethylsiloxysilicate, crosslinked methylpolysiloxane, aminopropyl dimethicone, alkylmethicone, (dimethicone / vinyl dimethicone) crosspolymer, (stearoxymethicone / dimethicone) copolymer, (dimethylsiloxane / methylcetyloxysiloxane) copolymer, simethicone, stearyl dimethicone, cetearyl Tyl dimethicone silicone, methyl hydrogen polysiloxane, diphenyl dimethicone, phenyl trimethicone, polyether modified organopolysiloxane, polyoxyalkylene alkylmethyl polysiloxane-methyl polysiloxane copolymer, alkoxy modified polysiloxane and other silicone oils, erythritol, glycerin, xylitol, diglycerin, dipropylene glycol, sorbitol, trehalose, polyethylene glycol, polyoxyethylene glycerin, polypropylene, polyoxypropylene glyceryl ether,Polyoxypropylene diglyceryl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene butyl ether, polyoxyethylene methyl glucoside, polyglycerin, maltitol, mannitol and other polyhydric alcohols, fluorine-modified organopolysiloxane, perfluorodecane, perfluorooctane, perfluoropolyether and other fluorine-based oils, dextrin fatty acid ester, sucrose fatty acid ester, starch fatty acid ester, 12-hydroxystearic acid, aluminum isostearate, calcium stearate Oil-based gelling agents such as calcium, ethylhexyl methoxycinnamate, polysilicone-15, octocrellin, ethylhexyl salicylate, homosalate, phenylbenzimidazole sulfonic acid, t-butylmethoxydibenzoylmethane, oxybenzone and other ultraviolet absorbers, fine particle titanium oxide, fine particle zinc oxide, or ultraviolet scattering agents surface-treated with metal soap, silica, silicone, etc., alkyl sulfates, polyoxyethylene alkyl ether sulfates, N-acyl amino acid salts, alkyl ether carboxylates, fatty acid soaps, alkyl phosphates, poly Anionic surfactants such as oxyethylene alkyl ether phosphates and N-acyltaurine salts, betaine acetate type amphoteric surfactants, imidazoline type amphoteric surfactants, alkylamidopropyl betaine type amphoteric surfactants, alkylhydroxysulfobetaine type amphoteric surfactants, alkylcarboxymethylhydroxyethylimidazolinium betaine type amphoteric surfactants, and alkyldimethylamine oxide type amphoteric surfactants, propylene glycol fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene lanolin, polyoxyethylene lanolin alcohol, polyoxyethylene sorbit beeswax, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene sterol, polyoxyethylene hydrogenated sterol, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and polyethylene glycol fatty acid esters.Nonionic surfactants such as alkyl glyceryl ether, alkyl polyglycoside, alkyl alkanolamide, etc.; cationic surfactants such as alkylammonium salts, amidoamine, etc.; lecithin derivatives such as hydrogenated soybean phospholipid, hydroxylated soybean phospholipid, etc.; organic low molecular weight powders such as N-acyl lysine, natural organic powders such as starch, silk powder, cellulose powder, etc.; extender pigments such as talc, kaolin, mica, sericite, calcium carbonate, magnesium carbonate, silicic anhydride, barium sulfate, etc.; inorganic pigments such as red iron oxide, yellow iron oxide, black iron oxide, ultramarine, Prussian blue, chromium oxide, carbon black, etc.; white pigments such as titanium oxide, zinc oxide, etc.; synthetic polymer powders such as nylon powder and polyethylene powder, Red No. 201, Red No. 202 The following may be blended: organic pigment powders such as Red No. 226, Red No. 228, Orange No. 203, Orange No. 204, Blue No. 404, Yellow No. 401, Red No. 3, Red No. 104, Red No. 106, Orange No. 205, Yellow No. 4, Yellow No. 5, Green No. 3, and Blue No. 1; alcohols such as ethanol and isopropyl alcohol; chelating agents such as edetate, hydroxyethanediphosphate, polyphosphate, and gluconic acid; preservatives such as benzoates, photosensitizers, parabens, phenoxyethanol, salicylic acid, sorbic acid, and isopropylmethylphenol; whitening agents such as arbutin, ellagic acid, kojic acid, and ascorbate derivatives; vitamins, amino acids, glycyrrhizinic acid derivatives, plant extracts, fragrances, essential oils, and pH adjusters. [Example]

[0023] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the scope of the present invention is not limited to these examples.

[0024] <Synthesis Example 1> 121.8 g of isostearic acid and 317.7 g of polyglycerin (10% hydrate, hydroxyl value 845) were placed in a reaction vessel, and 0.4 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 250°C for 9 hours under a nitrogen stream, and 395.2 g of polyglyceryl isostearate with an esterification rate of 9.7% was obtained.

[0025] <Synthesis Example 2> 125.2 g of isostearic acid and 314.1 g of polyglycerin (10% hydrate, hydroxyl value 890) were placed in a reaction vessel, and 0.2 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 9 hours under a nitrogen stream, and 392.6 g of polyglyceryl isostearate with an esterification rate of 9.8% was obtained.

[0026] <Synthesis Example 3> 187.0 g of isostearic acid and 259.9 g of polyglycerin (10% hydrate, hydroxyl value 970) were placed in a reaction vessel, and 0.2 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 3 hours under a nitrogen stream, and 391.2 g of polyglyceryl isostearate with an esterification rate of 16.3% was obtained.

[0027] <Synthesis Example 4> 235.6 g of isostearic acid and 197.2 g of polyglycerin (10% hydrate, hydroxyl value 1070) were placed in a reaction vessel, and 0.2 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 5 hours under a nitrogen stream, and 394.4 g of polyglyceryl isostearate with an esterification rate of 23.3% was obtained.

[0028] <Synthesis Example 5> 305.5 g of isostearic acid and 123.2 g of polyglycerin (hydroxyl value 1350) were placed in a reaction vessel, and 0.04 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 8 hours under a nitrogen stream, and 395.3 g of polyglyceryl isostearate with an esterification rate of 36.3% was obtained.

[0029] <Synthesis Example 6> 94.3 g of lauric acid and 349.1 g of polyglycerin (10% hydrate, hydroxyl value 845) were placed in a reaction vessel, and 0.4 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 2 hours under a nitrogen stream, and 398.6 g of polyglyceryl laurate with an esterification rate of 9.7% was obtained.

[0030] <Synthesis Example 7> 96.9 g of lauric acid and 311.6 g of polyglycerin (10% hydrate, hydroxyl value 890) were placed in a reaction vessel, and 0.4 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 3 hours under a nitrogen stream, and 389.2 g of polyglyceryl laurate with an esterification rate of 10.8% was obtained.

[0031] <Synthesis Example 8> 110.0 g of myristic acid and 350.0 g of polyglycerin (10% hydrate, hydroxyl value 890) were placed in a reaction vessel, and 0.2 g of sodium hydroxide was added. After that, the reaction was carried out at 200 to 240°C for 6 hours under a nitrogen stream, yielding 390.9 g of polyglyceryl myristate with an esterification rate of 9.7%.

[0032] Examples 1 to 7 and Comparative Examples 1 to 6 Components (A) to (D) shown in Table 1 were mixed uniformly at 80°C, and the mixture was poured into stirred water at 80°C to prepare an aqueous ceramide solution, which was then evaluated for the following items.

[0033] [Crystallization suppression] The aqueous solutions obtained in the examples and comparative examples were visually inspected to evaluate whether or not ceramide crystals were precipitated. The results are shown in Table 1. (standard) ○: No crystal precipitation is observed ×: Crystal precipitation is observed

[0034] [Temporal stability (transmittance)] The aqueous solutions obtained in the examples and comparative examples were left to stand at 0, 25, and 40°C for one week, after which the transmittance was measured and the change in transmittance over time was evaluated. These results are shown in Table 1. (standard) ○: The change in transmittance is less than 3% △: Change in transmittance is 3% or more but less than 10% ×: The change in transmittance is 10% or more

[0035] [Stability over time (crystal precipitation)] The aqueous solutions obtained in the examples and comparative examples were left to stand at 0, 25, and 40°C for one week, and then visually inspected for the presence or absence of ceramide crystal precipitation. The results are shown in Table 1. (standard) ○: No crystal precipitation is observed ×: Crystal precipitation is observed

[0036] [Table 1]

[0037] Examples 1 to 7, which comprise a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization of 6 to 20 and a branched fatty acid having 8 to 22 carbon atoms and having an esterification rate of 8 to 20%, and a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization of 6 to 20 and a straight-chain fatty acid having 8 to 14 carbon atoms and having an esterification rate of 8 to 20%, in a mass ratio of 50 / 50 to 100 / 0, were superior in all respects of crystallization inhibition, transmittance stability over time, and crystal precipitation stability over time, compared to Comparative Example 1, which did not contain component (A), Comparative Examples 2 to 4, in which the mass ratio of component (A) to component (B) was not 50 / 50 to 100 / 0, and Comparative Examples 5 and 6, which used a polyglycerol fatty acid ester composed of a polyglycerol having an average degree of polymerization not of 6 to 20 and a branched fatty acid having 8 to 22 carbon atoms.

Claims

1. A crystallization inhibitor for ceramide or ceramide analogues, wherein the mass ratio of the following components (A) and (B) is (A) / (B)=50 / 50 to 100 / 0, and the hydroxyl value of the polyglycerol constituting at least one polyglycerol fatty acid ester of component (A) or component (B) is 800 to 870: (A) Polyglycerol fatty acid ester composed of polyglycerol having an average degree of polymerization of 6 to 20 and branched fatty acid having 8 to 22 carbon atoms (B) Polyglycerol fatty acid ester composed of polyglycerol having an average degree of polymerization of 6 to 20 and straight-chain fatty acids having 8 to 14 carbon atoms

2. 2. The crystallization inhibitor for ceramide or ceramide analogues according to claim 1, wherein the esterification rate of the component (A) polyglycerol fatty acid ester is 8 to 20%.

3. 3. The crystallization inhibitor for ceramide or ceramide analogues according to claim 1, wherein the esterification rate of the component (B) polyglycerol fatty acid ester is 8 to 20%.

4. A skin external preparation characterized in that the mass ratio of the following components (A) and (B) is (A) / (B) = 50 / 50 to 100 / 0, and the skin external preparation contains the following component (C): (A) Polyglycerol fatty acid ester composed of polyglycerol having an average degree of polymerization of 6 to 20 and branched fatty acid having 8 to 22 carbon atoms (B) Polyglycerol fatty acid ester composed of polyglycerol having an average degree of polymerization of 6 to 20 and straight-chain fatty acids having 8 to 14 carbon atoms (C) one or more substances selected from the group consisting of ceramides and ceramide analogues

5. The topical skin preparation according to claim 4, further comprising (D) an alkanediol.

Images