JP7798320B2 - Translucent or transparent topical skin preparation - Google Patents

Description

The present invention relates to a translucent or transparent topical skin preparation, and in particular, to a topical skin preparation with improved stability that combines a solid or semi-solid oil agent with a transparent or translucent solubilizing system.

Transparent or semi-solid topical skin preparations moisturize the stratum corneum by dissolving various moisturizers in water for the purpose of rehydrating and retaining moisture. However, preventing moisture evaporation is essential to improving skin texture. However, moisture applied to the stratum corneum evaporates over time, making it difficult to expect texture improvement. For this reason, formulations such as diluted water-in-oil (O/W) emulsions have been used, but these are thermodynamically unstable and have drawbacks in terms of usability, such as a sticky feel and lack of refreshing sensation.

To solve this problem, it is desirable to use a highly occlusive oil, specifically a solid or semi-solid oil. For example, Patent Document 1 discloses an oil-in-water microemulsion aimed at moisturizing the stratum corneum and improving its barrier function, which contains a polyglycerol fatty acid monoester with a degree of polymerization of 3-7 and 10-22 carbon atoms, a diester of a fatty acid diglycerol and a saturated dibasic acid, squalane, beeswax (solid wax), and jojoba oil. Furthermore, Patent Document 2 discloses a composition containing a branched fatty acid phytosteryl, a fatty acid triglyceride with 10-22 carbon atoms, squalane, beeswax (solid wax), and jojoba oil.

Furthermore, Patent Document 3 discloses a method for producing a thermodynamically unstable water-in-oil (O/W) emulsion, which produces a cloudy oil-in-water (O/W) emulsion containing an oil agent that is liquid at room temperature, a nonionic surfactant that is a hydrogenated phospholipid (HLB: 9-16), a divalent glycol, and water.

Japanese Patent Application Laid-Open No. 2008-056586 JP 2009-234920 A Japanese Patent Application Laid-Open No. 2007-254405

However, the technologies described in Patent Documents 1 and 2 were unable to achieve a refreshing feel due to the stickiness of the emulsion, which is a surfactant. Furthermore, because it is an emulsion, the oil droplets inevitably coalesce over time, and the oil droplets are not sufficiently stable over time.

Patent Document 3 also discloses a method for producing a milky white oil-in-water (O/W) type lotion and emulsion in one product that is stable even at low viscosity in order to provide a refreshing feel when used. However, because it requires the incorporation of an oil that is liquid at room temperature, it does not have the same skin-improving effect as Patent Documents 1 and 2, and improvements in this area have been desired.

The object of the present invention is to solve the problems of the prior art and to provide an external skin preparation with improved stability that combines a solid or semi-solid oil agent with a transparent or translucent solubilizing system.

As a result of extensive research into resolving the above-mentioned problems, the inventors discovered that the above-mentioned objective could be achieved by combining a solid or semi-solid oil agent with a specific surfactant, leading to the completion of the present invention.

That is, the translucent or transparent external preparation for skin of the present invention is
(A) a solid or semi-solid oil solution;
(B) a hydrocarbon oil agent that is liquid at room temperature;
(C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24);
(D) a higher alcohol having 18 to 22 carbon atoms;
(E) a polyhydric alcohol;
and (F) water, wherein (1-40 E.O.) means that the number of moles of oxyethylene added is 1 to 40, (1-30 P.O.) means that the number of moles of oxypropylene added is 1 to 30, and (C16-C24) means that the alkyl group has 16 to 24 carbon atoms.

Furthermore, the translucent or transparent topical skin preparation of the present invention preferably contains (G) polyoxyethylene hydrogenated castor oil, and the (G) polyoxyethylene hydrogenated castor oil is preferably one or more selected from the group consisting of PEG-5 hydrogenated castor oil, PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil.

Furthermore, in the translucent or transparent topical skin preparation of the present invention, the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24) is preferably one or more selected from the group consisting of PPG-6 decyltetradeceth-30, PPG-6 decyltetradeceth-12, PPG-13 decyltetradeceth-24, PPG-6 decyltetradeceth-20, PPG-4 ceteth-1, PPG-8 ceteth-1, PPG-4 ceteth-10, PPG-4 ceteth-20, PPG-5 ceteth-20, PPG-8 ceteth-20, and PPG-23 steareth-34.

The present invention makes it possible to provide an external skin preparation with improved stability, which combines a solid or semi-solid oil agent with a transparent or translucent solubilizing system.

The translucent or transparent external skin preparation of the present invention will be specifically described below.
The translucent or transparent topical skin preparation of the present invention is characterized by comprising (A) a solid or semi-solid oil, (B) a hydrocarbon oil that is liquid at room temperature, (C) a polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24), (D) a higher alcohol having 18 to 22 carbon atoms, (E) a polyhydric alcohol, and (F) water. The topical skin preparation is a solubilized system that exhibits a transparent or translucent appearance, has a skin texture improving effect, and is non-sticky and refreshing to use. Furthermore, by incorporating an oil that is solid or semi-solid at room temperature and has a high occlusive effect in a thermodynamically stable solubility range, the topical skin preparation has improved skin-improving effects and a non-sticky and refreshing feel. In the present invention, "semi-transparent" or "transparent" refers not only to visual observation, but also to a state in which transparency (L value in the L ^* a ^* b ^* color system) is 99.0 or higher, more preferably 99.4 or higher, and "semi-transparent" refers to a state in which it is 1 to 99. Furthermore, lightness is one of the attributes of color, and the degree of brightness of the color is expressed on a scale of 0.0 to 100.0, with an increase in the L value indicating greater transparency. Measurement can be performed using a spectrophotometer or the like, but is not particularly limited as long as it is a method capable of measuring other ordinary lightnesses. For example, measurement can be performed using a spectrophotometer, with the transparency measured when 5 mL of purified water is placed in a glass cell and light is transmitted through it being 100, and the transparency measured when light is completely blocked and no light is transmitted being 0.

In the present invention, the term "solid or semi-solid oil agent (A)" refers to an oil having a melting point above room temperature (approximately 20-25°C). It is not particularly limited as long as it can be used in ordinary topical skin preparations and can achieve the effects of the present invention. Examples of such solid or semi-solid oil agents (A) include highly occlusive ozokerite, ceresin, microcrystalline wax, petrolatum, candelilla wax hydrocarbons, beeswax, mango butter, coconut oil, palm oil, palm kernel oil, cocoa butter, shea butter, hydrogenated coconut oil, beef tallow, milk fat, horse tallow, spermaceti, lanolin, reduced lanolin, adsorbed and refined lanolin, acetated lanolin, lanolin fatty acids, hard lanolin fatty acids, lanolin alcohol, lecithin (30°C, room temperature paste), phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, and sphingolipids such as sphingomyelin. Protein, phospholipids such as lysolecithin, hydrogenated soybean phospholipid, partially hydrogenated soybean phospholipid, hydrogenated egg yolk phospholipid, cholesterol, dihydrocholesterol, phytosterol, sterols such as cholic acid, sapogenins, saponins, cholesteryl stearate, cholesteryl isostearate, cholesteryl oleate, N-lauroyl-L-glutamic acid di(cholesteryl/behenyl/octyldodecyl), N-lauroyl-L-glutamic acid di(phytosteryl/behenyl/2-octyldodecyl), cholesteryl hydroxystearate, macadamia nut oil fatty acid cholesteryl, macadamia nut oil fatty acid phytosteryl Steryl, Cholesteryl Lanolinate (Soft Fatty Acid), Cholesteryl Lanolinate (Hard Fatty Acid), Cholesteryl Long-Chain Branched Fatty Acid, Cholesteryl Nonanoate, Cholesteryl Lanolinate (Soft Fatty Acid), Cholesteryl Lanolinate (Hard Fatty Acid), Cholesteryl Long-Chain Branched Fatty Acid, Octyldodecyl Lanolinate, Cetyl Palmitate, Hydrogenated Castor Oil Isostearate, Isopropyl Lanolinate, Cetyl Lactate, Hydrogenated Castor Oil Isostearate Paste, Glyceryl Trihydrogenated Rosinate, Glyceryl Behenate/Eicosadioate, Dipentaerythrityl Hexahydroxystearate/Hexastearate/Hexarosinate, Glycol Distearate (Distearic Acid) Examples of suitable hydroxystearic acids include ethylene glycol dimer dilinoleate (phytosteryl/isostearyl/cetyl/stearyl/behenyl dimer dilinoleate), dimer dilinoleyl dimer dilinoleate, dimer dilinoleyl hydrogenated rosin condensate, hydrogenated castor oil dimer dilinoleate, derivatives of dimer acids or dimer diols such as hydroxyalkyl (C16-18) hydroxydimer dilinoleyl ether, cetanol, myristyl alcohol, lauryl alcohol, cetostearyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, chimyl alcohol, batyl alcohol, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, coconut oil fatty acid monoethanolamide (cocamide MEA), lauric acid monoisopropanolamide (lauramide MIPA), palmitic acid monoethanolamide (palutamide MEA), and the like.

In addition, in the present invention, the hydrocarbon oil (B) that is liquid at room temperature is not particularly limited as long as it can be used in ordinary topical skin preparations and can achieve the effects of the present invention. Examples of such hydrocarbon oil (B) that is liquid at room temperature include liquid paraffin (mineral oil), heavy liquid isoparaffin, light liquid isoparaffin, α-olefin oligomer, polyisobutene, hydrogenated polyisobutene, polybutene, squalane, olive-derived squalane, and squalene. In the present invention, "room temperature" refers to the temperature in a typical room (room temperature), for example, a temperature range of 20 to 25°C.

Furthermore, in the present invention, liquid oils other than (B) hydrocarbon oils that are liquid at room temperature can be blended together, provided that the effects of the present invention can be achieved. Examples of such oils other than (B) hydrocarbon oils that are liquid at room temperature include safflower oil, olive oil, castor oil, avocado oil, sesame oil, tea oil, evening primrose oil, wheat germ oil, macadamia nut oil, hazelnut oil, kukui nut oil, rosehip oil, meadowfoam oil, persic oil, tea tree oil, peppermint oil, corn oil, rapeseed oil, sunflower oil, wheat germ oil, linseed oil, cottonseed oil, soybean oil, peanut oil, rice bran oil, and hydrogenated Vegetable oils and fats such as castor oil, jojoba oil, hydrogenated jojoba oil, etc., animal oils and fats such as egg yolk oil, mink oil, turtle oil, etc., orange roughy oil, liquid lanolin, acetated liquid lanolin, N-lauroyl-L-glutamic acid di(cholesteryl/octyldodecyl), N-lauroyl-L-glutamic acid di(phytosteryl/octyldodecyl), acyl sarcosine alkyl esters such as N-lauroyl sarcosine isopropyl, isostearic acid Phytosteryl, octyldodecyl myristate, 2-hexyldecyl myristate, octyldodecyl isostearate, cetyl 2-ethylhexanoate, hexyldecyl ethylhexanoate, isotridecyl isononanoate, isononyl isononanoate, octyl isononanoate, isotridecyl isononanoate, isodecyl neopentanoate, isostearyl neopentanoate, oleyl oleate, octyldodecyl oleate, ricinoleate Octyldodecyl leate, octyldodecyl erucate, ethyl oleate, avocado oil fatty acid ethyl ester, isopropyl myristate, isopropyl palmitate, octyl palmitate, isopropyl isostearate, methylheptyl laurate, methylheptyl myristate, methylheptyl palmitate, methylheptyl isostearate, diethyl sebacate, diisopropyl sebacate, dioctyl sebacate, adipate Monoalcohol carboxylic acid esters such as diisopropyl phosphate, dibutyloctyl sebacate, diisobutyl adipate, dioctyl succinate, and triethyl citrate, diisostearyl malate, glyceryl trioctanoate, glyceryl trioleate, glyceryl triisostearate, glyceryl diisostearate, caprylic/capric triglyceride, caprylic/capric/myristic/stearic triglyceride, trimethylolpropane triethylhexanoate, trimethylolpropane triisostearate, neopentyl glycol diethylhexanoate, neopentyl glycol dicaprate, propylene glycol dioleate, pentaerythrityl tetraethylhexanoate, ditrimethylolpropane isostearate/sebacic acid oligoester, diglyceryl diisostearate, and tetraisostearin. Examples of suitable oleic acid surfactants include polyglyceryl-2 dimer dilinoleate, polyglyceryl-10 nonaisostearate, methylpentanediol dineopentanoate, diisostearyl dimer dilinoleate, di(isostearyl/phytosteryl) dimer dilinoleate, dimer dilinoleyl diisostearate, oleyl alcohol, jojoba alcohol, glyceryl oleate, hexyldecanol, isostearyl alcohol, 2-octyldodecanol, and dimer diol; aralkyl alcohols and derivatives such as benzyl alcohol; isostearic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, isohexadecanoic acid; and fatty acid alkanolamides such as coconut oil fatty acid diethanolamide (cocamide DEA), lauric acid diethanolamide (lauramide DEA), and coconut oil fatty acid methylethanolamide (cocamide methyl MEA).

In addition, in the present invention, the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24) is not particularly limited as long as it can be used in ordinary topical skin preparations and the effects of the present invention can be obtained, but it is preferable that it is one or more types selected from the group consisting of PPG-6 decyltetradeceth-30, PPG-6 decyltetradeceth-12, PPG-13 decyltetradeceth-24, PPG-6 decyltetradeceth-20, PPG-4 ceteth-1, PPG-8 ceteth-1, PPG-4 ceteth-10, PPG-4 ceteth-20, PPG-5 ceteth-20, PPG-8 ceteth-20, and PPG-23 steareth-34. Specific examples include NIKKOL SG-DTD630 (trade name), NIKKOL PEN-4612 (trade name), NIKKOL SG-DTD620 (trade name), NIKKOL PBC-31 (trade name), NIKKOL PBC-33 (trade name), NIKKOL SG-C420 (trade name), and NIKKOL PBC-44 (trade name), all manufactured by Nikko Chemicals Co., Ltd.

Furthermore, in the present invention, the (D) higher alcohol having 18 to 22 carbon atoms can improve the solubilization of the (A) solid or semi-solid oil agent and the (B) hydrocarbon oil agent that is liquid at room temperature. Such (D) higher alcohol having 18 to 22 carbon atoms is not particularly limited as long as it can be used in ordinary topical skin preparations and can achieve the effects of the present invention, but examples include stearyl alcohol, cetostearyl alcohol, oleyl alcohol, behenyl alcohol, isostearyl alcohol, hexyldecanol, octyldodecanol, decyltetradecanol, arachyl alcohol, arachidyl alcohol, and behenyl alcohol. These higher alcohols may be used alone or in combination.

Furthermore, in the present invention, the (E) polyhydric alcohol improves the solubility of the surfactant, and dihydric polyhydric alcohols in particular can improve the moisturizing effect of the stratum corneum. Such (E) polyhydric alcohols are not particularly limited as long as they can be used in ordinary topical skin preparations and achieve the effects of the present invention, but examples include glycerin, 1,3-butylene glycol, propylene glycol, isopentyldiol, diglycerin, sorbitol, hexylene glycol, pentylene glycol, and polyethylene glycol. These (E) polyhydric alcohols may be used alone or in combination.

In addition, in the present invention, the (F) water is essential for the skin-improving effect of hydrating and retaining moisture in the skin. Such (F) water is not particularly limited as long as it can be used in ordinary topical skin preparations and can achieve the effects of the present invention, but purified water, etc., can be used.

Furthermore, the translucent or transparent topical skin preparation of the present invention preferably contains (G) polyoxyethylene hydrogenated castor oil, and the (G) polyoxyethylene hydrogenated castor oil is preferably one or more selected from the group consisting of PEG-5 hydrogenated castor oil, PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil. (G) The polyoxyethylene hydrogenated castor oil is not particularly limited as long as it can be used in ordinary topical skin preparations and can achieve the effects of the present invention. Examples include NIKKOL HCO-5 (trade name), NIKKOL HCO-10 (trade name), NIKKOL HCO-20 (trade name), NIKKOL HCO-30 (trade name), NIKKOL HCO-40 (trade name), NIKKOL HCO-50 (trade name), NIKKOL HCO-60 (trade name), NIKKOL HCO-80 (trade name), and NIKKOL HCO-100 (trade name), all manufactured by Nikko Chemicals Co., Ltd.

Furthermore, the translucent or transparent topical skin preparation of the present invention preferably contains a pH adjuster. Such pH adjusters are not particularly limited as long as they can be used in ordinary topical skin preparations and can achieve the effects of the present invention. Examples include citric acid, malic acid, tartaric acid, lactic acid, glycolic acid, glutamic acid, aspartic acid, malonic acid, succinic acid, adipic acid, and 2-amino-2-methyl-1-propanol.

The translucent or transparent topical skin preparation of the present invention preferably contains a stabilizer. Such stabilizers improve the stability of the topical skin preparation by using sequestering agents, antioxidants, preservatives, etc. The stabilizer is not particularly limited as long as it can be used in ordinary topical skin preparations and achieves the effects of the present invention. Examples of the stabilizer include sequestering agents such as hydroxyethanediphosphonic acid, edetic acid and its salts, antioxidants such as dibutylhydroxytoluene, butylhydroxyanisole, sorbic acid, sodium sulfite, erythorbic acid, and L-cysteine hydrochloride, and preservatives such as methylparaben, ethylparaben, benzoic acid, benzoates, salicylic acid, salicylates, phenoxyethanol, water-soluble cationic antibacterial agents, ethylhexylglycerin, bisabolol, and poly-ε-lysine.

Furthermore, the translucent or transparent topical skin preparation of the present invention can contain surfactants other than the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24) and (G) polyoxyethylene hydrogenated castor oil, as long as the effects of the present invention can be achieved. Examples of such surfactants include propylene glycol fatty acid esters, glycerin fatty acid esters, polyglycerin and fatty acid esters, polyoxyethylene glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene lanolin/lanolin alcohol/beeswax derivatives, polyoxyethylene sterol/hydrogenated sterol, polyethylene glycol fatty acid esters, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamine/fatty acid amides, polyoxyethylene alkylphenyl formaldehyde condensates, and polyoxyethylene alkyl ether phosphoric acid/phosphate salts.

Furthermore, it is preferable that the translucent or transparent topical skin preparation of the present invention has a content of (A) solid or semi-solid oil of 1 to 5% by mass, a content of (B) hydrocarbon oil that is liquid at room temperature of 0.5 to 8% by mass, a content of (C) polyoxyethylenated (1 to 40 E.O.) and polyoxypropylenated (1 to 30 P.O.) alkyl (C16 to C24) of 1 to 8% by mass, a content of (D) higher alcohol having 18 to 22 carbon atoms of 0.5 to 2.0% by mass, a content of (E) polyhydric alcohol of 1 to 20% by mass, and (F) water adjusted to 100% by mass. By using these amounts, it is possible to obtain a topical skin preparation that has a refreshing feel when used and has a skin texture improving effect, and in particular, the moisture evaporation inhibitory effect of the solid or semi-solid oil (A) is improved, and the hydrocarbon oil (B) that is liquid at room temperature can be used both to inhibit moisture evaporation and as a solvent for the solid or semi-solid oil (A).

Furthermore, it is more preferable that the content of the (A) solid or semi-solid oil is 1 to 3 mass %, the content of the (B) hydrocarbon oil that is liquid at room temperature is 1 to 5 mass %, the content of the (C) polyoxyethylenated (1 to 40 E.O.) and polyoxypropylenated (1 to 30 P.O.) alkyl (C16 to C24) is 1 to 3 mass %, the content of the (D) higher alcohol having 18 to 22 carbon atoms is 0.5 to 1.0 mass %, the content of the (E) polyhydric alcohol is 5 to 12 mass %, and the content of the (F) water is adjusted to 100 mass %. By using these blending amounts, it is possible to obtain an external skin preparation that has a refreshing feel when used and has a texture-improving effect. In particular, the texture-improving effect of the (A) solid or semi-solid oil is further improved, the (B) hydrocarbon oil that is liquid at room temperature is used as an emollient and a solvent for the (A) solid or semi-solid oil, and the (D) higher alcohol having 18 to 22 carbon atoms is dissolved in the (C) polyoxyethylenated (1 to 40 E.O.) and polyoxypropylenated (1 to 30 P.O.) alkyl (C16 to C24) palisade layer, thereby increasing the number of micelles and further reducing the stickiness of the (E) polyhydric alcohol.

Furthermore, the translucent or transparent topical skin preparation of the present invention preferably contains 1 to 5% by mass of the polyoxyethylene hydrogenated castor oil (G), and more preferably 2.5 to 3.5% by mass. By incorporating this amount, the stability of the translucent or transparent topical skin preparation of the present invention can be further improved.

In the present invention, topical skin preparations are those that can be used on the human body, etc., and belong to the classification of ordinary cosmetics, and do not exclude uses such as quasi-drugs and pharmaceuticals. Furthermore, the topical skin preparations also include uses such as basic cosmetics, makeup cosmetics, and hair cosmetics.

Furthermore, in the present invention, other ingredients can be added as appropriate, provided that the effects of the present invention are not impaired. Any ingredients other than those listed above can be blended within the qualitative and quantitative ranges, including ingredients typically blended in topical skin preparations, such as moisturizers, fragrances, various vitamins, UV absorbers, powders and colorants, medicinal ingredients, inorganic salts, plant extracts, and other useful ingredients.

Extract components include, for example, chamomile extract, parsley extract, honeysuckle extract, rice extract, rice bran extract, hop extract, Phellodendron bark extract, Job's tears extract, Swertia japonica extract, Melilot extract, birch extract, licorice extract, peony extract, soapwort extract, loofah extract, chili pepper extract, lemon extract, gentian extract, perilla extract, aloe extract, rosemary extract, sage extract, thyme extract, eucalyptus extract, tea extract, seaweed extract, cucumber extract, clove extract, carrot extract, horse chestnut extract, witch hazel extract, mulberry extract, tangerine peel extract, pecan nut extract, grapefruit extract, Shikuwasa extract, passion fruit extract, loquat extract, grape extract, rose fruit extract, Sophora flavescens extract, and peppermint extract.

Moisturizing ingredients include, for example, xylitol, maltitol, sodium chondroitin sulfate, elastin, glucosamine, hyaluronic acid, cyclodextrin, collagen, bile salts, etc.

Examples of active ingredients include vitamins such as vitamin A, vitamin B, vitamin C, vitamin D, and vitamin E and their derivatives, glycyrrhizinic acid and its derivatives, various salts such as urea, creatinine, CoQ10, astaxanthin, polyphenols, and ceramides.

In addition, in the present invention, translucent or transparent topical skin preparations can be produced using conventional methods for producing topical skin preparations, and a method of heating oil phase components and aqueous phase components can be used.

In the present invention, one example of a method for producing a translucent or transparent topical skin preparation is a method in which the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24) is dissolved in the (E) polyhydric alcohol, and an oil phase prepared by dissolving the (A) solid or semi-solid oil, the (B) hydrocarbon oil that is liquid at room temperature, and the (D) higher alcohol having 18 to 22 carbon atoms is added and mixed.

Another example of a method for producing a translucent or transparent topical skin preparation is to dissolve the (E) polyhydric alcohol in the (F) water to form an aqueous phase, dissolve the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24), dissolve the (A) solid or semi-solid oil, the (B) hydrocarbon oil that is liquid at room temperature, and the (D) higher alcohol having 18 to 22 carbon atoms in the aqueous phase to form an oil phase, and mix the oil phase with the aqueous phase to solubilize it.

Another example of a method for producing a translucent or transparent topical skin preparation involves dissolving the (E) polyhydric alcohol in the (F) water to form an aqueous phase, dissolving the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24), dissolving the (A) solid or semi-solid oil, the (B) hydrocarbon oil that is liquid at room temperature, and the (D) higher alcohol having 18 to 22 carbon atoms to form an oil phase, mixing the oil phase with the aqueous phase, and, after solubilization, mixing in the pH adjuster and/or stabilizer.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples. Furthermore, the numerical values in the formulations below indicate mass %.

(Examples 1 to 3, Comparative Examples 1 to 5)
The topical skin preparations of Examples 1 to 3 and Comparative Examples 1 to 5 were prepared according to the manufacturing methods described below and using the formulations shown in Tables 1 and 2 below. The obtained topical skin preparations were evaluated using the evaluation methods described below, and the results are shown in Tables 1 and 2 below.

(Manufacturing method)
Polyhydric alcohols (pentylene glycol and BG) were dissolved in purified water to form an aqueous phase. Nonionic surfactants (PPG-4 ceteth-20 and PEG-10 hydrogenated castor oil) were dissolved, and the solid and semi-solid oils, liquid oils, and higher alcohols listed in Tables 1 and 2 below were dissolved therein to form an oil phase. The oil phase was mixed with the aqueous phase to solubilize it, and then phenoxyethanol was mixed and dissolved.

(Evaluation method)
(appearance, stability)
The stability of the obtained external skin preparations was visually observed on the day of preparation and one and three months after preparation, and evaluated according to the following evaluation criteria.
◎: Translucent to transparent 〇: Translucent △: Cloudy ×: Cloudy, separated

(Usability)
A sensory test was conducted on the usability of "stickiness" and "refreshing" by a panel (sensory testers aged 27 to 75, one male and one female). The evaluation was on a 5-point scale, with a positive statement for "stickiness" marked as "yes" (+) and a negative mark marked as "no," with +2 and -2 added to the center (±). Similarly, for "refreshing," a positive mark was marked as "refreshing" and a negative mark as "not refreshing."

The results in Tables 1 and 2 show that the topical skin preparations of Examples 1 to 3 were stable and easy to use. On the other hand, the topical skin preparations of Comparative Examples 1 to 5 were unstable and felt sticky to the touch.

(Examples 4 to 7, Comparative Example 6)
The topical skin preparations of Examples 4 to 7 and Comparative Example 6 were prepared according to the above-mentioned manufacturing method and with the formulations shown in Table 3 below. The stability of the obtained topical skin preparations was evaluated using the above-mentioned evaluation method, and the results are also shown in Table 3 below.

From the results in Table 3, the external skin preparations of Examples 4 to 7 had good stability, while the external skin preparation of Comparative Example 6 had poor stability.

Claims (3)

(A) 1 to 5 mass% of a solid or semi-solid oil solution;
(B) 0.5 to 8 mass% of a hydrocarbon oil agent that is liquid at room temperature;
(C) 1 to 8% by mass of polyoxyethylenated (1 to 40 E.O.) and polyoxypropylenated (1 to 30 P.O.) alkyl (C16 to C24);
(D) 0.5 to 2.0 mass% of a higher alcohol having 18 to 22 carbon atoms;
(E) 1 to 20% by mass of a polyhydric alcohol;
(F) water, and a translucent to transparent solubilized skin external preparation characterized by comprising: (G) polyoxyethylene hydrogenated castor oil,
2. The translucent or transparent solubilized external skin preparation according to claim 1, wherein the polyoxyethylene hydrogenated castor oil (G) is one or more selected from the group consisting of PEG-5 hydrogenated castor oil, PEG-10 hydrogenated castor oil, PEG-20 hydrogenated castor oil, PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-50 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-80 hydrogenated castor oil, and PEG-100 hydrogenated castor oil. The translucent to transparent solubilized topical skin preparation according to claim 1 or 2, wherein the (C) polyoxyethylenated (1-40 E.O.) and polyoxypropylenated (1-30 P.O.) alkyl (C16-C24) is one or more selected from the group consisting of PPG-6 decyltetradeceth-30, PPG-6 decyltetradeceth-12, PPG-13 decyltetradeceth-24, PPG-6 decyltetradeceth-20, PPG-4 ceteth-1, PPG-8 ceteth-1, PPG-4 ceteth-10, PPG-4 ceteth-20, PPG-5 ceteth-20, PPG-8 ceteth-20, and PPG-23 steareth-34.