JP7656352B2 - Foaming skin care product - Google Patents

Description

The present invention relates to a foaming skin preparation for topical use.

Traditionally, topical skin preparations containing synthetic or natural extracts that promote blood circulation in the skin have been used.

Since the effects of these extracts are insufficient when used in small amounts and are too irritating to the skin when used in large amounts, external skin preparations containing carbon dioxide gas to promote blood circulation have been proposed. Most of these generate carbon dioxide gas by reacting an acidic substance with a carbon dioxide gas generating substance. Carbon dioxide gas-foaming external skin preparations have traditionally contained plant extracts such as pine bark extracts that are considered to be effective (see Patent Document 1).
On the other hand, it has long been known that carbon dioxide gas has the effect of promoting blood circulation, and for example, a pack cosmetic product that has a warming sensation and contains a heat-generating substance is known (see Patent Document 2).

JP 2014-88345 A Japanese Patent Application Publication No. 08-268828

However, there are cases where the effects of plant extracts such as pine bark extract are low, and there has been a demand for the development of a carbon dioxide gas foaming skin preparation that is more effective in improving skin conditions, such as by whitening the skin color, increasing the skin's moisture content, reducing the amount of water loss, and improving skin elasticity.
Furthermore, although the foaming properties, foam duration, physical irritation, and the like of conventionally known pack agents containing carbon dioxide gas have been studied, there has not yet been sufficient study of the effect of carbon dioxide gas in improving skin conditions, nor has there been sufficient study of the usability and stability of the products, or the feel after rinsing.

In the present invention, therefore, by blending a new ingredient into a carbon dioxide gas foaming skin preparation for external use, various studies were conducted to find an active ingredient that improves the skin condition, is excellent in usability, safety and stability, has a good feel after rinsing, and can further enhance the effects of carbon dioxide gas.
As a result, the inventors have found that the effects of carbon dioxide gas can be enhanced and the above-mentioned problems can be solved by incorporating a specific active ingredient into various carbon dioxide gas foaming skin preparations for external use, thus completing the present invention.

The present invention is a carbon dioxide gas foaming skin preparation for external use, which contains, in the same preparation or in two or more preparations, an acidic substance, a carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas, and a thickener, and further contains ascorbic acid glucoside, allantoin, estradiol, dipotassium glycyrrhizinate, monoammonium glycyrrhizinate, β-glycyrrhizinic acid, stearyl glycyrrhetinate, tranexamic acid, d-camphor, dl-α-tocopherol acetate, dl-α-tocopherol nicotinate, D-pantothenyl alcohol, pantothenyl ethyl ether, ethinyl estradiol, salicylic acid, biotin, rezole, The present invention provides a carbon dioxide gas foaming skin preparation for external use that contains at least one selected from rusine, trichlorocarbanilide, triclosan, benzethonium chloride, sulfur, photosensitizer No. 201, phenol, pyridoxine hydrochloride, pyridoxine, zinc oxide, arbutin, magnesium L-ascorbyl phosphate, ascorbyl dipalmitate, placenta, retinol, and retinol palmitate (however, when the carbon dioxide gas foaming skin preparation for external use is made up of one agent, it is to be mixed with a water-containing substance at the time of use, and when it is made up of two or more agents, one of the agents is to contain water) (hereinafter also referred to simply as "skin preparation for external use").

The present invention also provides a carbon dioxide gas foaming skin preparation for external use (hereinafter simply referred to as a "kit for a skin preparation for external use" or "kit") which is a two-agent kit of any of the following (1) to (3). In each of the following kits, the first agent and the second agent are mixed when used.
(1) a first agent which is an acid-containing composition containing an acidic substance and water;
and a second agent which is a base-containing composition containing a carbon dioxide gas generating substance which reacts with the acidic substance to generate carbon dioxide gas, wherein the first agent and/or the second agent contain a thickener, and further wherein the first agent and/or the second agent contain ascorbic acid glucoside, allantoin, estradiol, dipotassium glycyrrhizinate, monoammonium glycyrrhizinate, β-glycyrrhizinic acid, stearyl glycyrrhetinate, tranexamic acid, d-camphor, dl-α-tocopherol acetate, dl-α-tocopherol nicotinate, The composition contains at least one selected from the group consisting of ferrol, D-pantothenyl alcohol, pantothenyl ethyl ether, ethinyl estradiol, salicylic acid, biotin, resorcinol, trichlorocarbanilide, triclosan, benzethonium chloride, sulfur, photosensitizer No. 201, phenol, pyridoxine hydrochloride, pyridoxine, zinc oxide, arbutin, magnesium L-ascorbyl phosphate, ascorbyl dipalmitate, placenta, retinol, and retinol palmitate.
(2) a first agent which is an acid-containing composition containing an acidic substance;
and a second agent which is a base-containing composition containing water and a carbon dioxide gas generating substance which reacts with the acidic substance to generate carbon dioxide gas, wherein the first agent and/or the second agent contain a thickener, and further wherein the first agent and/or the second agent contain ascorbic acid glucoside, allantoin, estradiol, dipotassium glycyrrhizinate, monoammonium glycyrrhizinate, β-glycyrrhizinic acid, stearyl glycyrrhetinate, tranexamic acid, d-camphor, dl-α-tocopherol acetate, dl-α-tocopherol nicotinate, The composition contains at least one selected from the group consisting of copherol, D-pantothenyl alcohol, pantothenyl ethyl ether, ethinyl estradiol, salicylic acid, biotin, resorcinol, trichlorocarbanilide, triclosan, benzethonium chloride, sulfur, photosensitizer No. 201, phenol, pyridoxine hydrochloride, pyridoxine, zinc oxide, arbutin, magnesium L-ascorbyl phosphate, ascorbyl dipalmitate, placenta, retinol, and retinol palmitate.
(3) a first agent which is an acid- and base-containing composition containing an acidic substance and a carbon dioxide gas generating substance which reacts with the acidic substance to generate carbon dioxide gas;
and a second agent which is a composition containing water, wherein the first agent and/or the second agent contains a thickener, and further wherein the first agent and/or the second agent contains ascorbic acid glucoside, allantoin, estradiol, dipotassium glycyrrhizinate, monoammonium glycyrrhizinate, β-glycyrrhizinic acid, stearyl glycyrrhetinate, tranexamic acid, d-camphor, dl-α-tocopherol acetate, dl-α-tocopherol nicotinate, D-pantothenyl arsenate, glycyrrhizinic acid ... It contains at least one member selected from the group consisting of chol, pantothenyl ethyl ether, ethinyl estradiol, salicylic acid, biotin, resorcin, trichlorocarbanilide, triclosan, benzethonium chloride, sulfur, photosensitizer No. 201, phenol, pyridoxine hydrochloride, pyridoxine, zinc oxide, arbutin, magnesium L-ascorbyl phosphate, ascorbyl dipalmitate, placenta, retinol, and retinol palmitate.

The present invention also provides a carbon dioxide gas foamable skin preparation for topical use (hereinafter also simply referred to as "composition for topical skin preparation" or "composition"), which is a one-part composition having the following composition to be mixed with a water-containing substance at the time of use.
Composition: Contains an acidic substance, a carbonate, and a thickener, and further contains at least one selected from ascorbic acid glucoside, allantoin, estradiol, dipotassium glycyrrhizinate, monoammonium glycyrrhizinate, β-glycyrrhizinic acid, stearyl glycyrrhetinate, tranexamic acid, d-camphor, dl-α-tocopherol acetate, dl-α-tocopherol nicotinate, D-pantothenyl alcohol, pantothenyl ethyl ether, ethinyl estradiol, salicylic acid, biotin, resorcinol, trichlorocarbanilide, triclosan, benzethonium chloride, sulfur, photosensitizer No. 201, phenol, pyridoxine hydrochloride, pyridoxine, zinc oxide, arbutin, magnesium L-ascorbyl phosphate, ascorbyl dipalmitate, placenta, retinol, and retinol palmitate.

According to the present invention, by blending a specific active ingredient, the effect of carbon dioxide gas is enhanced, and the effect of whitening the skin, increasing the moisture content of the skin, reducing the amount of moisture evaporation, improving skin elasticity, etc. is achieved, thereby improving the skin condition, and the effect of carbon dioxide gas can be further enhanced by providing excellent usability such as ease of mixing and application, safety, and stability, and a good feeling of use after rinsing. Furthermore, it is possible to provide a carbon dioxide gas foaming topical skin preparation that improves the condition of stratum corneum cells or/and promotes skin turnover, as well as having excellent skin cell activation effects and new effects such as reducing the size of skin pores and improving skin texture, and a kit and composition from which the topical skin preparation can be obtained.

FIG. 1A shows the results of skin condition measurements for Comparative Examples 1 to 3 and Examples 1-1 to 1-10, where (a) shows the results for color difference and (b) shows the results for water evaporation. FIG. 1B shows the results of skin condition measurements in Comparative Examples 1 to 3 and Examples 1-1 to 1-10, (c) showing the results for stratum corneum moisture content, and (d) showing the results for elasticity. FIG. 2A shows the results of skin condition measurements in Examples 1-11 to 1-20, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 2B shows the results of skin condition measurements in Examples 1-11 to 1-20, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 3A shows the results of skin condition measurements in Examples 1-21 to 1-30, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 3B shows the results of skin condition measurements in Examples 1-21 to 1-30, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 4A shows the results of skin condition measurements in Examples 1-31 to 1-35, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 4B shows the results of skin condition measurements in Examples 1-31 to 1-35, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 5A shows the results of skin condition measurements in Examples 2-1 to 2-5, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 5B shows the results of skin condition measurements in Examples 2-1 to 2-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 6A shows the results of skin condition measurements in Examples 3-1 to 3-5, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 6B shows the results of skin condition measurements in Examples 3-1 to 3-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 7A shows the results of skin condition measurements in Examples 4-1 to 4-5, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 7B shows the results of skin condition measurements in Examples 4-1 to 4-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 8A shows the results of skin condition measurements in Examples 5-1 to 5-5, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 8B shows the results of skin condition measurements in Examples 5-1 to 5-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 10A shows the results of skin condition measurements in Examples 6-1 to 6-5, where (a) shows the results of color difference and (b) shows the results of water evaporation. FIG. 10B shows the results of skin condition measurements in Examples 6-1 to 6-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 10A shows the results of skin condition measurements for Comparative Example 4 and Examples 7-1 to 7-5, where (a) shows the results for color difference and (b) shows the results for water evaporation. FIG. 10B shows the results of skin condition measurements in Comparative Example 4 and Examples 7-1 to 7-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 11A shows the results of skin condition measurements for Comparative Example 5 and Examples 8-1 to 8-5, where (a) shows the results for color difference and (b) shows the results for water evaporation. FIG. 11B shows the results of skin condition measurements in Comparative Example 5 and Examples 8-1 to 8-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 12A shows the results of skin condition measurements for Comparative Example 6 and Examples 9-1 to 9-5, where (a) shows the results for color difference and (b) shows the results for water evaporation. FIG. 12B shows the results of skin condition measurements in Comparative Example 6 and Examples 9-1 to 9-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 13A shows the results of skin condition measurements for Comparative Example 7 and Examples 10-1 to 10-5, where (a) shows the results for color difference and (b) shows the results for water evaporation. FIG. 13B shows the results of skin condition measurements in Comparative Example 7 and Examples 10-1 to 10-5, where (c) shows the results for stratum corneum moisture content and (d) shows the results for elasticity. FIG. 14 shows the results of the turnover test for Comparative Examples 1 to 3 and Examples 1-1 to 1-10. FIG. 15 shows the results of the turnover test for Examples 1-11 to 1-20. FIG. 16 shows the results of the turnover test for Examples 1-21 to 1-30. FIG. 17 shows the results of the turnover test for Examples 1-31 to 1-35. FIG. 18 shows the results of the turnover test for Examples 2-1 to 2-5. FIG. 19 shows the results of the turnover test for Examples 3-1 to 3-5. FIG. 20 shows the results of the turnover test for Examples 4-1 to 4-5. FIG. 21 shows the results of the turnover test for Examples 5-1 to 5-5. FIG. 22 shows the results of the turnover test for Examples 6-1 to 6-5. FIG. 23 shows the results of the turnover test for Comparative Example 4 and Examples 7-1 to 7-5. FIG. 24 shows the results of the turnover test for Comparative Example 5 and Examples 8-1 to 8-5. FIG. 25 shows the results of the turnover test for Comparative Example 6 and Examples 9-1 to 9-5. FIG. 26 shows the results of the turnover test for Comparative Example 7 and Examples 10-1 to 10-5. FIG. 27 shows images of stratum corneum cells observed before and after the use of the foaming skin topical preparations of Comparative Example 1, Examples 1-19, Examples 2-3, and Examples 4-3. FIG. 28 shows the evaluation results of cell activation activity in Comparative Examples 8 to 10 and Examples 11 to 13.

Hereinafter, the skin topical preparation, the kit for the skin topical preparation, and the composition for the skin topical preparation of the present invention will be described based on their preferred embodiments. The kit for the skin topical preparation and the composition for the skin topical preparation of the present invention are each a form of the foaming skin topical preparation of the present invention. The foaming skin topical preparation of the present invention may contain the acidic substance, the carbon dioxide gas generating substance, the thickener, and the specific components described below all in the same preparation, or may contain them separately in multiple preparations. When divided into multiple preparations, the four components may be divided in any manner. However, the acidic substance, the carbon dioxide gas generating substance, and the amount of water necessary to generate carbon dioxide gas are not included in the same preparation. The water content of the same preparation containing the acidic substance and the carbon dioxide gas generating substance is preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 8% by mass or less.

The carbon dioxide gas foaming skin topical agent according to the present invention can be used in any form, be it a cosmetic, a quasi-drug, or a pharmaceutical product. From the standpoint of effectiveness and ease of use, however, it is preferably used as a cosmetic or a quasi-drug product (medicated cosmetics), and is particularly preferably used as a quasi-drug product (medicated cosmetics).

The carbon dioxide gas foaming skin preparation for external use according to the present invention can be applied externally to the skin, including the scalp and hair, and can be used in various forms, such as pack products, hair growth products, facial cleansers, cleansing products, lotions, milky lotions, beauty gels, shampoos, and conditioners. When washed off, it is preferably used in pack products, facial cleansers, and cleansing products.

First, the main components used in the topical skin preparation, the kit for topical skin preparation, and the composition for topical skin preparation of the present invention will be described. Hereinafter, the term "topical skin preparation" may refer to the topical skin preparation (e.g., the kit for topical skin preparation, the composition for topical skin preparation) in which the carbon dioxide gas generating substance, the acidic substance, and water come into contact with each other and the three are not yet mixed, or may refer to the carbon dioxide gas-containing topical skin preparation after they are mixed (e.g., one obtained by mixing the two agents in the kit, or one obtained by mixing the composition for topical skin preparation with a water-containing substance). Which one is referred to will be determined according to the context. Below, the components contained in the topical skin preparation, the kit, and the composition of the present invention will be described together.

<Acidic Substances>
The acidic substance used in the present invention may be either an inorganic acid or an organic acid, and one or more of these may be used.

Inorganic acids include phosphoric acid, potassium dihydrogen phosphate, sodium dihydrogen phosphate, sodium sulfite, potassium sulfite, sodium pyrosulfite, potassium pyrosulfite, sodium acid hexametaphosphate, potassium acid hexametaphosphate, sodium acid pyrophosphate, potassium acid pyrophosphate, sulfamic acid, etc.

Examples of organic acids include linear fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid, or salts thereof; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, fumaric acid, maleic acid, phthalic acid, isophthalic acid, and terephthalic acid, or salts thereof; acidic amino acids such as glutamic acid and aspartic acid, or salts thereof; oxyacids such as glycolic acid, malic acid, tartaric acid, citric acid, lactic acid, hydroxyacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, salicylic acid, gallic acid, tropic acid, ascorbic acid, and gluconic acid, or salts thereof; and inorganic acids such as phosphoric acid, sulfurous acid, and salts thereof, and one or more of these can be used.

Among these, citric acid, ascorbic acid, malic acid and succinic acid are preferred from the standpoint of safety and solubility in water.

From the viewpoint of efficiently exerting a cosmetic effect, the content of the acidic substance in the skin topical preparation of the present invention is preferably 0.01 to 30 parts by mass, more preferably 0.05 to 20 parts by mass, relative to 100 parts by mass of the skin topical preparation. Similarly, the content of the acidic substance in the acid-containing composition of the kits (1) and (2) and the content of the acidic substance in the acid- and base-containing composition of the kit (3) are preferably 0.01 to 30 parts by mass, more preferably 0.05 to 20 parts by mass, relative to 100 parts by mass of the total amount of the two agents in the corresponding kit. In the present specification, the amount of the skin topical preparation may be the total amount of each agent in the kit at the start of mixing the components of each kit when the skin topical preparation of the present invention is a kit of two or more agents, and when the skin topical preparation is obtained by mixing a one-agent skin topical preparation composition and a water-containing substance, it may be the total amount of the composition and the water-containing substance at the start of mixing.

Furthermore, the content of the acidic substance in the acid-containing composition (acid-containing aqueous composition) in the kit (1) of the present invention is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less, in the acid-containing composition (acid-containing aqueous composition).
The content of the acidic substance in the acid-containing composition in the kit (2) of the present invention is preferably 0.1 mass % or more and 90 mass % or less, and more preferably 0.5 mass % or more and 80 mass % or less, of the solid content of the acid-containing composition.
The content of the acidic substance in the acid- and base-containing composition in the kit (3) of the present invention is preferably 0.01% by mass or more and 50% by mass or less, and more preferably 0.05% by mass or more and 40% by mass or less, of the solid content of the acid- and base-containing composition.
The content of the acidic substance in the composition for topical skin preparations of the present invention is preferably 0.01% by mass or more and 40% by mass or less, and more preferably 0.05% by mass or more and 30% by mass or less, of the solid content of the composition for topical skin preparations.

<Carbon dioxide generating substances>
The carbon dioxide gas generating substance used in the present invention which reacts with the acidic substance to generate carbon dioxide gas may be any substance which reacts with the acidic substance to generate carbon dioxide gas.

Carbon dioxide gas generating substances include carbonates such as sodium carbonate, calcium carbonate, potassium carbonate, magnesium carbonate, and sodium sesquicarbonate, and bicarbonates such as ammonium bicarbonate, potassium bicarbonate, sodium bicarbonate, lithium bicarbonate, cesium bicarbonate, magnesium bicarbonate, and calcium bicarbonate, and one or more of these may be used. Among these, bicarbonates are preferably used, and sodium bicarbonate is more preferred in that it can achieve a suitable foaming power.

The content of the carbon dioxide gas generating substance in the topical skin preparation of the present invention is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less, relative to 100 parts by mass of the topical skin preparation. Similarly, the content of the carbon dioxide gas generating substance in the base-containing composition of the kits (1) and (2) and the content of the carbon dioxide gas generating substance in the acid- and base-containing composition of the kit (3) are preferably 0.01 parts by mass or more and 30 parts by mass or less, and more preferably 0.05 parts by mass or more and 20 parts by mass or less, relative to 100 parts by mass of the total amount of the two agents in the corresponding kit.

The content of the carbon dioxide gas generating substance in the base-containing composition in the kit (1) of the present invention is preferably 0.1 mass % or more and 90 mass % or less, and more preferably 0.5 mass % or more and 80 mass % or less, of the solid content of the base-containing composition.
The content of the carbon dioxide gas generating substance in the base-containing composition (water-containing composition) in the kit (2) of the present invention is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less, in the base-containing composition.
The content of the carbon dioxide gas generating substance in the acid- and base-containing composition in the kit (3) of the present invention is preferably 0.01% by mass or more and 50% by mass or less, and more preferably 0.05% by mass or more and 40% by mass or less, of the solid content of the acid- and base-containing composition.
The content of the carbon dioxide gas generating substance in the composition for topical skin preparation of the present invention is preferably 0.01 mass% or more and 40 mass% or less, and more preferably 0.05 mass% or more and 30 mass% or less, of the solid content of the composition for topical skin preparation.

<Thickener>
Examples of thickeners used in the present invention include various types of thickeners that can be used in the fields of cosmetics and pharmaceuticals. Examples of thickeners that can be used include synthetic polymers, semi-synthetic polymers, natural polymers, clay minerals, etc. Specifically, synthetic polymers include hydrophilic synthetic polymers such as carboxyvinyl polymers, polyvinyl alcohol, acrylic acid/alkyl methacrylate copolymers, acrylates/alkyl acrylate crosspolymers, polyacrylic acid, polyacrylamide, polyalkylacrylamide/polyacrylamide copolymers, carboxymethylcellulose, cationized cellulose, and (PEG-240/decyltetradeceth-20/HDI) copolymers, and semi-synthetic polymers include cellulose derivatives such as carboxymethylcellulose or its salts, methylcellulose, ethylcellulose, propylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, and sulfonated cellulose derivatives. Other semi-synthetic polymers include propylene glycol alginate, ethylene glycol alginate, dextrin fatty acid esters, gelatin fatty acid esters, and gelatin fatty acid amides. Examples of natural polymers include polysaccharides and derivatives thereof, such as xanthan gum, succinoglycan, carrageenan, guar gum, locust bean gum, celluloses, galactan, gum arabic, tragacanth gum, tamarind gum, agar, agarose, mannan, curdlan, alginic acid or its salts, gum arabic, pectin, quince seed, starch, algae colloid, chondroitin sulfate or its salts, chitosan and its derivatives, nucleic acid or its salts, ribonucleic acid or its salts, water-soluble proteins such as casein, collagen, gelatin, albumin, fibroin, elastin, keratin, and sericin, mucopolysaccharides such as hyaluronic acid or its salts, and chondroitin sulfate, etc. Examples of clay minerals include laponite, bentonite, smectite kaolinite, and montmorillonite.
Preferred examples of the above salts include alkali metal salts, such as sodium salts and potassium salts.

In the present invention, one or more of the above thickeners can be used, but among the above thickeners, it is preferable to use one that is highly soluble or dispersible in water, since this can reduce the rough feeling on the skin caused by undissolved or undispersed components during use. Here, the solubility in water can be determined by whether the product has sufficient viscosity by instantly dissolving or dispersing in water when water at about room temperature is added and stirred, and whether lumps are not formed during dissolution or dispersion.

In terms of the above-mentioned solubility and dispersibility in water, preferred thickeners include, for example, carboxyvinyl polymer, carboxymethylcellulose or its salts, polyvinyl alcohol, PEG-240/decyltetradeceth-20/HDI) copolymer, sodium polyacrylate, acrylic acid/alkyl methacrylate copolymer, xanthan gum, succinoglycan, carrageenan, guar gum, locust bean gum, cellulose derivatives (celluloses), galactan, gum arabic, tragacanth gum, tamarind gum, agar, mannan, curdlan, alginic acid or its salts, collagen, gelatin, albumin, etc., and particularly preferred thickeners include alginic acid or its salts, hydroxyethyl ether, carboxymethylcellulose or its salts, xanthan gum, carrageenan, tamarind gum, and albumin.

The amount of the thickener contained in the skin topical preparation of the present invention is preferably 0.01 to 40 parts by mass, more preferably 0.1 to 30 parts by mass, relative to 100 parts by mass of the skin topical preparation. Similarly, the content of the thickener in the acid-containing composition and/or base-containing composition in the kits (1) and (2) and the content of the thickener in the acid- and base-containing composition and/or water-containing composition in the kit (3) are preferably 0.01 to 40 parts by mass, more preferably 0.1 to 30 parts by mass, relative to 100 parts by mass of the total amount of the two agents in the corresponding kit. The amount of the thickener in the acid-containing composition and/or base-containing composition referred to here is the amount of the thickener if one of them contains a thickener, and the total amount if both contain a thickener, and the same applies to the amount of the thickener in the base-containing composition and/or water-containing composition.

The content of the thickener in the composition for topical skin preparation of the present invention is preferably 0.1% by mass or more and 40% by mass or less, and more preferably 0.5% by mass or more and 30% by mass or less, based on the solid content of the composition for topical skin preparation.

<Water>
The water that can be used in the present invention may be water that can be used in cosmetics, external medicines, quasi-drugs, etc., but purified water, distilled water, membrane-filtered water, and ion-exchanged water are preferred.

The amount of water in the topical skin preparation of the present invention (or the amount of water used in the topical skin preparation) is preferably 20 parts by mass or more and 95 parts by mass or less, and more preferably 30 parts by mass or more and 90 parts by mass or less, relative to 100 parts by mass of the topical skin preparation, from the viewpoint of fully achieving the cosmetic effect of the present invention. In the case of a composition for topical skin preparations, the amount of water referred to here is the ratio of water to the total amount of water and the amount of composition. Similarly, the content of water in the kits (1) to (3) is preferably 20 parts by mass or more and 95 parts by mass or less, and more preferably 30 parts by mass or more and 90 parts by mass or less, relative to 100 parts by mass of the total amount of the two agents in the corresponding kit. The amount of water in the kit referred to here is the total amount of water in the two agents, and is the amount of water in the agent when only one of the two agents contains water.

<Polyhydric alcohol>
In the present invention, it is preferable that the skin external preparation contains a polyhydric alcohol, since it can exert a high moisturizing effect by combining with a specific component described later. Examples of polyhydric alcohols include polyglycerols such as glycerin, diglycerin, triglycerin, and tetraglycerin, ethylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, 1,3-propanediol, 1,2-pentanediol, sorbitol, polyglycerol derivatives, reducing sugars such as glucose, fructose, glyceraldehyde, lactose, arabinose, and maltose, and sugar alcohols such as erythritol, maltitol, sorbitol, and xylitol, and one or more of these may be used in combination. Among them, those having 2 or more carbon atoms are preferable from the viewpoint of a high moisturizing effect, and those having a valency of 2 or more are preferable.

The amount of polyhydric alcohol contained in the skin topical preparation of the present invention is preferably 1 part by mass or more and 80 parts by mass or less, more preferably 5 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the skin topical preparation, from the viewpoint of fully exerting the cosmetic effect by combination with the above-mentioned specific component. Similarly, the content of polyhydric alcohol in the acid-containing composition and/or base-containing composition in the kits (1) and (2) and the content of polyhydric alcohol in the acid- and base-containing composition and/or water-containing composition in the kit (3) are preferably 1 part by mass or more and 80 parts by mass or less, more preferably 5 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the total amount of the two agents in the corresponding kit. The amount of polyhydric alcohol in the acid-containing composition and/or base-containing composition referred to here is the amount of polyhydric alcohol when one of them contains a polyhydric alcohol, and the total amount when both contain a polyhydric alcohol, and the same applies to the amount of polyhydric alcohol in the base-containing composition and/or water-containing composition.

One of the features of the topical skin preparation of the present invention is that it contains a specific active ingredient (hereinafter also referred to as a specific ingredient). Such an ingredient is described in detail below.

<Ascorbic acid glucoside>
Examples of ascorbic acid glucoside include 2-O-α-D-glucopyranosyl-L-ascorbic acid (also called AA-2G, ascorbic acid-2-glucoside, L-ascorbic acid 2-glucoside, etc.). Ascorbic acid glucoside may be isolated from nature or biochemically synthesized. Ascorbic acid glucoside is said to have an inhibitory effect on melanin production and is used in cosmetics and quasi-drugs for whitening. The present inventors have found that the effect of this ascorbic acid glucoside is efficiently exerted in a carbon dioxide gas-forming external skin preparation obtained by mixing it with an acidic substance, a carbon dioxide gas-generating substance, a thickener, and water. Ascorbic acid glucoside may be contained in any of the kits (1) to (3), or may be contained in a one-agent type composition for an external skin preparation. When ascorbic acid glucoside is included in a two-drug kit, it may be used in any of the following forms: one of the two drugs is in gel form and the other is in solid form, one of the two drugs is in gel form and the other is in liquid form, both drugs are in gel form, one of the two drugs is in liquid form and the other is in solid form, or both drugs are in liquid form. The drugs containing the various specific ingredients described below, including ascorbic acid glucoside, may be in solid, liquid, or gel form.

In the present invention, the amount of ascorbic acid glucoside in the skin topical preparation is preferably 0.01% by mass or more and 20% by mass or less, from the viewpoint of efficiently exerting the advantageous effects of ascorbic acid glucoside. From this viewpoint, the amount of ascorbic acid glucoside in the skin topical preparation is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.05% by mass or more and 10% by mass or less, and particularly preferably 0.1 parts by mass or more and 5 parts by mass or less. Similarly, the content of ascorbic acid glucoside in the acid-containing composition and/or base-containing composition in the kits (1) and (2) and the content of ascorbic acid glucoside in the acid- and base-containing composition and/or water-containing composition in the kit (3) are preferably 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.05 parts by mass or more and 10 parts by mass or less, and particularly preferably 0.1 parts by mass or more and 5 parts by mass or less, relative to the total amount of the two agents in the corresponding kit (100 parts by mass). The amount of ascorbic acid glucoside in the acid-containing composition and/or base-containing composition referred to here means the amount of ascorbic acid glucoside when one of them contains ascorbic acid glucoside, and means the total amount when both contain ascorbic acid glucoside. The same applies to the amount of ascorbic acid glucoside in the acid- and base-containing composition and/or water-containing composition.

When ascorbic acid glucoside is included in the kit (1), it may be included in either the acid-containing composition (water-containing composition) or the base-containing composition. When ascorbic acid glucoside is included in the acid-containing composition of the kit (1), from the viewpoint of efficiently exerting the advantageous effects of ascorbic acid glucoside, its content in the acid-containing composition is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less. When ascorbic acid glucoside is included in the base-containing composition of the kit (1), its content in the solid content of the base-containing composition is preferably 0.1% by mass or more and 90% by mass or less, and more preferably 0.5% by mass or more and 80% by mass or less.

When ascorbic acid glucoside is included in the kit (2), it is preferable that it is included in the acid-containing composition, since the effect of ascorbic acid glucoside can be efficiently exerted in the skin topical preparation. On the other hand, when it is included in the base-containing composition, it is difficult for it to exist stably in the kit. When ascorbic acid glucoside is included in the acid-containing composition of the kit (2), its content is preferably 90% by mass or less of the solid content of the acid-containing composition, and more preferably 0.1% by mass or more and 80% by mass or less.

When ascorbic acid glucoside is included in the kit (3), it may be included in either the acid- and carbonate-containing composition or the water-containing composition. When ascorbic acid glucoside is included in the acid- and carbonate-containing composition of the kit (3), its content is preferably 0.1% by mass to 50% by mass, and more preferably 0.5% by mass to 40% by mass, of the solid content of the acid- and carbonate-containing composition. When ascorbic acid glucoside is included in the water-containing composition of the kit (3), its content is preferably 0.01% by mass to 20% by mass, and more preferably 0.05% by mass to 10% by mass, of the water-containing composition.

The content of ascorbic acid glucoside in the composition for topical skin preparation of the present invention is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 0.5% by mass or more and 20% by mass or less, based on the solid content of the composition for topical skin preparation.

<Other specific ingredients>
The skin topical preparation, the kit for skin topical preparation, and the composition for skin topical preparation of the present invention can exhibit beauty effects and the like due to the inclusion of specific active ingredients other than ascorbic acid glucoside. Such ingredients are listed below. The preferred ratio of the specific ingredient contained in the kit for skin topical preparation of the present invention to the total amount of the two agents is the same as the preferred amount of the specific ingredient in the skin topical preparation shown below. The preferred content of the specific ingredient in the composition for skin topical preparation is the same as the preferred amount of the specific ingredient in the solid content of the skin topical preparation shown below.

Allantoin is a compound having the composition C ₄ H ₆ N ₄ O ₃ , and is a diureide of glyoxylic acid. It is also known as 5-ureidohydantoin or glyoxydiureide, and is known as an anti-inflammatory agent. When the topical skin preparation contains allantoin, the amount of allantoin in the topical skin preparation is preferably 0.001% by mass or more and 20% by mass or less, and more preferably 0.01% by mass or more and 10% by mass or less. The amount of allantoin is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less, in the solid content of the topical skin preparation.

When allantoin is contained in the acid-containing composition of the kit (1), its content in the acid-containing composition is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less. When allantoin is contained in the base-containing composition of the kit (1), its content in the solid content of the base-containing composition is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less.

When allantoin is contained in the acid-containing composition of the kit (2), its content is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less, based on the solid content of the acid-containing composition. When allantoin is contained in the base-containing composition of the kit (2), its content is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less, based on the solid content of the acid-containing composition.

When allantoin is contained in the acid- and carbonate-containing composition of the kit (3), its content is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.05% by mass or more and 20% by mass or less, based on the solid content of the acid- and carbonate-containing composition. When allantoin is contained in the aqueous composition of the kit (3), its content is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less, based on the solid content of the acid- and carbonate-containing composition.

Tranexamic acid, also known as trans-4-(aminomethyl)cyclohexanecarboxylic acid, is known as an anti-inflammatory agent and a skin whitening agent. When a topical skin preparation contains tranexamic acid, the amount of tranexamic acid in the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less. The amount of tranexamic acid in the solid content of the topical skin preparation is preferably 0.1% by mass or more and 80% by mass or less, and more preferably 1% by mass or more and 70% by mass or less.

When tranexamic acid is contained in the acid-containing composition of the kit (1), its content in the acid-containing composition is preferably 0.1% by mass or more and 60% by mass or less, and more preferably 1% by mass or more and 50% by mass or less. When tranexamic acid is contained in the base-containing composition of the kit (1), its content in the solid content of the base-containing composition is preferably 1% by mass or more and 90% by mass or less, and more preferably 5% by mass or more and 80% by mass or less.

When tranexamic acid is contained in the acid-containing composition of the kit (2), its content is preferably 1% by mass or more and 90% by mass or less, and more preferably 5% by mass or more and 80% by mass or less, based on the solid content of the acid-containing composition. When tranexamic acid is contained in the base-containing composition of the kit (2), its content is preferably 0.1% by mass or more and 60% by mass or less, and more preferably 1% by mass or more and 50% by mass or less, based on the solid content of the acid-containing composition.

When tranexamic acid is contained in the acid- and carbonate-containing composition of the kit (3), its content is preferably 0.1% by mass or more and 80% by mass or less, and more preferably 1% by mass or more and 75% by mass or less, based on the solid content of the acid- and carbonate-containing composition. When tranexamic acid is contained in the aqueous composition of the kit (3), its content is preferably 0.01% by mass or more and 30% by mass or less, and more preferably 0.1% by mass or more and 20% by mass or less, based on the solid content of the acid- and carbonate-containing composition.

The chemical name of d-camphor is (1R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one. It is a bicyclic monoterpene ketone found in camphor trees and the like, and is obtained by steam distillation of wood pieces. When a skin topical preparation contains d-camphor, the amount of d-camphor in the skin topical preparation is preferably 0.001% to 10% by mass. The amount of d-camphor in the solid content of the skin topical preparation is preferably 0.01% to 10% by mass.

Salicylic acid is a compound of _the chemical formula _C7H6O3 . When the topical skin preparation contains salicylic acid, the amount of salicylic acid in the topical skin preparation is preferably 0.0001% by mass or more and 10% by mass _or less. The amount of salicylic acid in the solid content of the topical skin preparation is preferably 0.001% by mass or more and 10% by mass or less.

Biotin is called D-[(+)-cis-hexahydro-2-oxo-1H-thieno-(3,4)-imidazole-4-valeric acid] and is a water-soluble vitamin classified as a B vitamin. When a skin topical preparation contains biotin, the amount of biotin in the skin topical preparation is preferably 0.0001% by mass or more and 1% by mass or less. The amount of biotin is preferably 0.0001% by mass or more and 10% by mass or less of the solid content of the skin topical preparation.

Resorcin is a compound represented by the chemical formula C ₆ H ₄ (OH) ₂ and corresponds to 1,3-dihydroxybenzene. When the topical skin preparation contains resorcin, the amount of resorcin in the topical skin preparation is preferably 0.001% by mass or more and 10% by mass or less. The amount of resorcin is preferably 0.01% by mass or more and 20% by mass or less of the solid content of the topical skin preparation.

Trichlorocarbanilide is also called triclocarban or 3,4,4'-trichlorocarbanilide. When a topical skin preparation contains trichlorocarbanilide, the amount of trichlorocarbanilide in the topical skin preparation is preferably 0.001% by mass or more and 10% by mass or less. In addition, the amount of trichlorocarbanilide in the solid content of the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less.

Triclosan is also known as 5-chloro-2-(2',4'-dichlorophenoxy)phenol. When a topical skin preparation contains triclosan, the amount of triclosan in the topical skin preparation is preferably 0.0001% by mass or more and 10% by mass or less. The amount of triclosan in the solid content of the topical skin preparation is preferably 0.001% by mass or more and 10% by mass or less.

Benzethonium chloride is represented by the chemical formula _C27H42ClNO2 and is a type _{of cationic} surfactant. When the skin topical preparation contains benzethonium chloride, the amount of benzethonium chloride in the skin topical preparation is preferably 0.0001% by mass or more and 10% by mass or less. The amount of benzethonium chloride in the solid content of the skin topical preparation is preferably 0.001% by mass or more and 10% by mass or less.

Sulfur is an element represented by the chemical formula S. When a topical skin preparation contains sulfur, the amount of sulfur in the topical skin preparation is preferably 0.001% by mass or more and 20% by mass or less. The amount of sulfur in the solid content of the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less.

Photosensitizer No. 201 is also called pionin. When a topical skin preparation contains Photosensitizer No. 201, the amount of photosensitizer No. 201 in the topical skin preparation is preferably 0.0001% by mass or more and 5% by mass or less. The amount of pionin is preferably 0.0005% by mass or more and 10% by mass or less of the solid content of the topical skin preparation.

Pyridoxine is a water-soluble compound known as 4,5-bis(hydroxymethyl)-2-methylpyridin-3-ol, or vitamin B6. When the topical skin preparation contains pyridoxine, the amount of pyridoxine in the topical skin preparation is preferably 0.0001% by mass or more and 5% by mass or less. The amount of pyridoxine in the solid content of the topical skin preparation is preferably 0.0005% by mass or more and 10% by mass or less.

Pyridoxine hydrochloride is pyridoxine converted to hydrochloride and is also called 5-hydroxy-6-methylpyridine-3,4-dimethyl monohydrochloride. When the topical skin preparation contains pyridoxine hydrochloride, the amount of pyridoxine hydrochloride in the topical skin preparation is preferably 0.001% by mass or more and 10% by mass or less. The amount of pyridoxine hydrochloride in the solid content of the topical skin preparation is preferably 0.01% by mass or more and 10% by mass or less.

Zinc oxide is represented by the chemical formula ZnO. When the topical skin preparation contains zinc oxide, the amount of zinc oxide in the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less. Also, the amount of zinc oxide in the solid content of the topical skin preparation is preferably 0.05% by mass or more and 20% by mass or less.

Examples of arbutin include β-arbutin and α-arbutin, with β-arbutin, also known as 4-(β-D-glucopyranosyloxy)phenol, being the most common. When the topical skin preparation contains arbutin, the amount of arbutin in the topical skin preparation is preferably 0.01% to 20% by mass, and more preferably 0.1% to 10% by mass. The amount of arbutin is preferably 0.1% to 50% by mass, and more preferably 1% to 40% by mass, of the solid content of the topical skin preparation.

When arbutin is contained in the acid-containing composition of the kit (1), its content in the acid-containing composition is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 20% by mass or less. When arbutin is contained in the base-containing composition of the kit (1), its content in the solid content of the base-containing composition is preferably 1% by mass or more and 90% by mass or less, and more preferably 5% by mass or more and 85% by mass or less.

When arbutin is contained in the acid-containing composition of the kit (2), its content is preferably 1% by mass or more and 90% by mass or less, and more preferably 5% by mass or more and 85% by mass or less, based on the solid content of the acid-containing composition. When arbutin is contained in the base-containing composition of the kit (2), its content is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 20% by mass or less, based on the solid content of the acid-containing composition.

When arbutin is contained in the acid- and carbonate-containing composition of the kit (3), its content is preferably 1% by mass or more and 80% by mass or less, and more preferably 5% by mass or more and 70% by mass or less, based on the solid content of the acid- and carbonate-containing composition. When arbutin is contained in the aqueous composition of the kit (3), its content is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 20% by mass or less, based on the solid content of the acid- and carbonate-containing composition.

Magnesium L-ascorbyl phosphate is also known as magnesium L-ascorbic acid 2-phosphate. When the topical skin preparation contains magnesium L-ascorbic acid 2-phosphate, the amount of magnesium L-ascorbic acid 2-phosphate in the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less. Also, the amount of magnesium L-ascorbyl phosphate in the topical skin preparation is preferably 0.05% by mass or more and 20% by mass or less of the solid content of the topical skin preparation.

Ascorbyl dipalmitate is also known as L-ascorbic acid 2,6-dipalmitate. When a topical skin preparation contains ascorbyl palmitate, the amount of ascorbyl palmitate in the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less. Also, the amount is preferably 0.05% by mass or more and 20% by mass or less of the solid content of the topical skin preparation.

Examples of glycyrrhizinic acid include β-glycyrrhizinic acid. Examples of glycyrrhizinic acid derivatives include dipotassium glycyrrhizinate (sometimes called dipotassium glycyrrhizinate), monoammonium glycyrrhizinate, and stearyl glycyrrhizinate. Monoammonium glycyrrhizinate may be anhydrous or hydrated. When the skin topical preparation contains these glycyrrhizinic acids and their derivatives, the amount of each of them and the total amount in the skin topical preparation is preferably 0.0001% by mass to 10% by mass, more preferably 0.001% by mass to 1% by mass. The content of glycyrrhizinic acid and its derivatives is preferably 0.001% by mass to 20% by mass, more preferably 0.005% by mass to 10% by mass, in the solid content of the skin topical preparation.

When glycyrrhizinic acid and its derivatives are contained in the acid-containing composition of the kit (1), the content is preferably 0.001% by mass to 10% by mass in the acid-containing composition, and more preferably 0.005% by mass to 5% by mass. When glycyrrhizinic acid and its derivatives are contained in the base-containing composition of the kit (1), the content is preferably 0.01% by mass to 20% by mass in the solid content of the base-containing composition, and more preferably 0.05% by mass to 10% by mass.

When glycyrrhizinic acid and its derivatives are contained in the acid-containing composition of the kit (2), the content is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less, based on the solid content of the acid-containing composition. Also, when glycyrrhizinic acid and its derivatives are contained in the base-containing composition of the kit (2), the content is preferably 0.001% by mass or more and 10% by mass or less, and more preferably 0.005% by mass or more and 5% by mass or less, based on the solid content of the acid-containing composition.

When glycyrrhizic acid and its derivatives are contained in the acid- and carbonate-containing composition of the kit (3), the content is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less, based on the solid content of the acid- and carbonate-containing composition. Also, when glycyrrhizic acid and its derivatives are contained in the aqueous composition of the kit (3), the content is preferably 0.001% by mass or more and 10% by mass or less, and more preferably 0.050% by mass or more and 5% by mass or less, based on the solid content of the acid- and carbonate-containing composition.

Each of the above preferred amounts of glycyrrhizinic acid and its derivatives may be the amount of one of glycyrrhizinic acid and its derivatives, or the total amount of glycyrrhizinic acid and its derivatives.

Retinol is also known as vitamin A. When a topical skin preparation contains retinol, the amount of retinol in the topical skin preparation is preferably 0.00001% by mass or more and 20% by mass or less. Also, the amount of retinol in the solid content of the topical skin preparation is preferably 0.00005% by mass or more and 10% by mass or less.

Retinol palmitate is also called vitamin A palmitate. When a topical skin preparation contains retinol palmitate, the amount of retinol palmitate in the topical skin preparation is preferably 0.00001% by mass or more and 20% by mass or less. Also, the amount of retinol palmitate in the topical skin preparation is preferably 0.00005% by mass or more and 10% by mass or less of the solid content of the topical skin preparation.

The generic name for estradiol is estra-1,3.5(10)triene-3,17β-diol. The generic name for ethinylestradiol is 17-ethynylestra-1,3,5(10)-triene-3β,17β-diol. When a topical skin preparation contains these estradiols, the amount of each estradiol and the total amount of each estradiol in the topical skin preparation is preferably 0.00001% by mass or more and 5% by mass or less. Also, the amount is preferably 0.00005% by mass or more and 10% by mass or less of the solid content of the topical skin preparation.

Both dl-α tocopherol acetate and dl-α tocopherol nicotinate are known as vitamin E derivatives. When a topical skin preparation contains dl-α tocopherol acetate and/or dl-α tocopherol nicotinate, the amount of each and the total amount of each is preferably 0.0001% by mass or more and 10% by mass or less in the topical skin preparation. It is also preferably 0.001% by mass or more and 10% by mass or less in the solid content of the topical skin preparation.

D-pantothenyl alcohol is also known as (R)-2,4-dihydroxy-N-(3-hydroxypropyl)-3,3-dimethylbutanamide. When the topical skin preparation contains D-pantothenyl alcohol, the amount of D-pantothenyl alcohol in the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less. Also, the amount of D-pantothenyl alcohol in the solid content of the topical skin preparation is preferably 0.05% by mass or more and 20% by mass or less.

Pantothenyl ethyl ether is also known as (2R)-N-(3-ethoxypropyl)-2,4-dihydroxy-3,3-dimethylbutanamide. When a topical skin preparation contains pantothenyl ethyl ether, the amount of pantothenyl ethyl ether in the topical skin preparation is preferably 0.001% by mass or more and 10% by mass or less. Also, the amount of pantothenyl ethyl ether in the solid content of the topical skin preparation is preferably 0.005% by mass or more and 10% by mass or less.

Phenol has the rational formula _C6H5OH and has a structure in which one hydrogen atom of benzene is replaced by _a hydroxyl group. When the skin topical preparation contains phenol, the amount of phenol in the skin topical preparation is preferably 0.001% by mass or more and 10% by mass or less. Also, the amount of phenol in the solid content of the skin topical preparation is preferably 0.005% by mass or more and 10% by mass or less.

Placenta is a general term for growth factors and other nutrients that promote cell division in animal, preferably pig, horse, cow, sheep, and human placentas, nutrients in the ovarian membrane of fish, and nutritional components in plant germs. The placenta used in the present invention is not particularly limited as long as it can be used as a regular cosmetic or quasi-drug. In the present invention, commercially available water-soluble extracts and powders can be used. When the topical skin preparation contains placenta, the amount of placenta in the topical skin preparation is preferably 0.01% by mass or more and 20% by mass or less. In addition, it is preferably 0.05% by mass or more and 20% by mass or less of the solid content of the topical skin preparation.

Of these specific ingredients, allantoin, dipotassium glycyrrhizinate, stearyl glycyrrhizinate, d-camphor, salicylic acid, arbutin and placenta are preferably contained in a two-component skin topical preparation kit in the present invention, and are particularly preferably contained in the kit (1) or (2). Needless to say, the specific ingredients, including these, may be contained in a one-component skin topical preparation composition or a two-component skin topical preparation kit. In particular, it is preferable that the specific ingredients are used in a two-component kit in terms of increasing the moisture content of the keratin after use and exhibiting an excellent turnover effect. In addition, the effect of improving skin condition and the effect of improving the feeling of use of the present invention are not limited by the type of thickener, but the desired effects among these can be further enhanced by the type of thickener combined with the specific ingredients.

Each specific component may be used in any of the following: one of the two agents is in a gel state and the other is in a solid state; one of the two agents is in a gel state and the other is in a liquid state; both agents are in a gel state; one of the two agents is in a liquid state and the other is in a solid state; or both agents are in a liquid state. For dl-α tocopherol acetate, it is preferable to use it in a formulation in which one of the two agents is in a gel state and the other is in a liquid state; both agents are in a gel state; one of the two agents is in a liquid state and the other is in a solid state; or both agents are in a liquid state. Furthermore, for placenta, it is preferable to use it in a formulation in which one of the two agents is in a gel state and the other is in a solid state; one of the two agents is in a gel state and the other is in a liquid state; both agents are in a gel state; or both agents are in a liquid state.

In addition, in the kits (1) to (3), it is preferable that estradiol, ethinyl estradiol, dl-α-tocopherol nicotinate, dl-α-tocopherol nicotinate, D-pantothenyl alcohol, pantothenyl ethyl ether, phenol, and placenta are contained in the aqueous composition (the acid-containing composition of the kit (1), the base-containing composition of the kit (2), and the aqueous composition of the kit (3)) in order to exert their effects. The amount of these specific components (estradiol, ethinyl estradiol, dl-α-tocopherol nicotinate, dl-α-tocopherol nicotinate, D-pantothenyl alcohol, pantothenyl ethyl ether, phenol, and placenta) contained in these aqueous compositions in the kits (1) to (3) is preferably in the same ratio as the preferred ratio of these specific components in the skin topical preparation described above in the total amount of the two agents.

In terms of exerting their effects, it is preferable for allantoin, glycyrrhizic acid and its derivatives, tranexamic acid, d-camphor, salicylic acid, biotin, resorcinol, trichlorocarbanilide, triclosan, benzonium chloride, sulfur, photosensitizer No. 201, pyridoxines, zinc oxide, arbutin, retinol, and retinol palmitate to be contained in the base-containing composition or acid-containing composition of kit (1), the acid-containing composition of kit (2), or the acid- and base-containing composition of kit (3). The amount of these specific ingredients (allantoin, glycyrrhizic acid and its derivatives, tranexamic acid, d-camphor, salicylic acid, biotin, resorcin, trichlorocarbanilide, triclosan, benzonium chloride, sulfur, photosensitizer No. 201, pyridoxines, zinc oxide, arbutin, retinol, retinol palmitate) contained in these compositions in the kits (1) to (3) is preferably in a preferred ratio to the total amount of the two agents similar to the preferred ratio of these specific ingredients to 100 parts by mass of the topical skin preparation described above.

<Other ingredients>
The skin external preparation of the present invention can use one or more of other active ingredients, preservatives, pH adjusters, oils and fats, fragrances, colorants, antioxidants, antibacterial and antifungal agents, alcohols, surfactants such as nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, inorganic salts, lubricants, and solvents, which are usually used in skin external preparations. These are contained in the composition for skin external preparations of the present invention. In addition, in the kit of the present invention, the added ingredients can be used in either the first agent or the second agent, or in both agents.

In the topical skin preparation, kit, and composition for topical skin preparation of the present invention, the total content of other components (water, acidic substances, carbon dioxide generating substances, thickeners, polyhydric alcohols, and components other than the specific components) is preferably 30% by mass or less, and more preferably 25% by mass or less.

<Kit dosage form and ingredient amounts>
The kits (1) to (3) will be described in more detail. In the kits (1) to (3), the aqueous composition of each kit (the acid-containing composition of the kit (1), the base-containing composition of the kit (2), and the aqueous composition of the kit (3)) may be in the form of a gel or liquid. The other agent of each kit (the base-containing composition of the kit (1), the acid-containing composition of the kit (2), and the acid- and base-containing composition of the kit (3)) may be in the form of a solid, liquid, gel, or the like. In the case of a solid form, it is preferable that the agent is in the form of granules, fine grains, or powder from the viewpoint of ease of mixing with the other agent and the cost of production.

<Water-containing composition of the kits (1) to (3)>
The preferred amounts of the carbon dioxide gas generating substance, the acidic substance and the specific component in the water-containing composition of the kits (1) to (3) are as described above. The water content in the water-containing composition of the kits (1) to (3) is preferably 20% by mass or more, particularly 30% by mass or more, from the viewpoint of mixability with the other components of each kit, and is preferably 95% by mass or less, particularly 90% by mass or less, from the viewpoint of containing other components and enhancing the cosmetic effect as a skin external preparation.

When the hydrous composition of the kits (1) to (3) contains a polyhydric alcohol, the proportion of the polyhydric alcohol in the hydrous composition is preferably 1% by mass or more, particularly 10% by mass or more, from the viewpoint of enhancing the moisturizing effect by combining with a specific component, etc., and is preferably 90% by mass or less, particularly 80% by mass or less, and especially 70% by mass or less, from the viewpoint of enhancing the cosmetic effect as a skin topical agent by including other components.

In addition, each of the hydrous compositions (1) to (2) preferably contains the above-mentioned acidic substance, carbon dioxide gas generating substance, and specific component in the above-mentioned amounts. In addition, each of the hydrous compositions (1) to (3) may contain moisturizing agents other than polyhydric alcohols, surfactants, pH adjusters, volatile alcohols, oils and fats, fragrances, animal and plant extracts, etc. For example, examples of moisturizing agents other than polyhydric alcohols include polyoxyalkylene alkyl glucoside, sodium lactate, sodium pyrrolidone carboxylate, almond, avocado, althea, aloe, mallow, ononis, oat, licorice, quince seed, sophora jasmine, gardenia, grapefruit, watercress, gentiana, geranium herb, burdock, wheat, saishin, cactus, soapwort, hawthorn, rehmannia, meadowsweet, ginger. , mallow, mulberry, thyme, cordyceps, houttuynia, peppermint, pearl barley, hamamelis, rose, cypress, coltsfoot, grape, prune, loofah, linden, hops, pine, quince, horse chestnut, melissa, cornflower, lily, lime, lavender, apple, rice and rice bran, blackcurrant, ibuki tora nomi, rose of the wild, Eleuthero, seaweed, and other plant extracts can be used alone or in combination with other extracts.

The viscosity of the liquid agent at 25°C is preferably less than 5000 mPa·s, more preferably less than 4000 mPa·s. The viscosity of the gel agent at 25°C is preferably 5000 Pa·s or more. This viscosity is measured, for example, by a viscometer (RVT model, manufactured by Brookfield). The amount of thickener in the liquid agent is preferably less than 0.05% by mass, more preferably less than 0.01% by mass, and particularly preferably less than 0.005% by mass. On the other hand, the amount of thickener in the gel agent is preferably 0.01% by mass or more, more preferably 0.05% by mass or more.

<Base-containing composition of kit (1), acid-containing composition of kit (2), and acid- and base-containing composition of kit (3)>
The preferred amounts of the acid, carbon dioxide gas generating substance, and specific component in these compositions are as described above. When these compositions are solid, the preferred amount and content of the thickener is 0.01% by mass or more and 20% by mass or less, particularly 0.05% by mass or more and 15% by mass or less, in these compositions when the other agent is in a gel state, from the viewpoints of good foaming, carbon dioxide gas retention, and exertion of the effects of the specific component, and when the other agent is in a liquid state, the preferred amount and content of the thickener is 0.01% by mass or more and 30% by mass or less, particularly 0.05% by mass or more and 25% by mass or less, in these compositions when the other agent is in a liquid state, from the viewpoints of easy mixing with the liquid agent, foaming, carbon dioxide gas retention, and exertion of the effects of the specific component.

As described above, the base-containing composition of the kit (1), the acid-containing composition of the kit (2), and the acid- and base-containing composition of the kit (3) may be in a gel or liquid form. In this case, the preferred amount of thickener in these compositions is the same as the preferred amount of the liquid or gel thickener in the water-containing composition of the kits (1) to (3) described above. In addition, when the base-containing composition of the kit (1), the acid-containing composition of the kit (2), and the acid- and base-containing composition of the kit (3) are in a gel or liquid form, the proportion of water in these compositions is preferably 7% by mass or more, particularly 10% by mass or more, and especially 20% by mass or more, from the viewpoint of foaming property, bubble persistence, etc., and is preferably 95% by mass or less, particularly 90% by mass or less, from the viewpoint of containing other components to enhance the cosmetic effect as a skin topical agent.

When the base-containing composition of the kit (1), the acid-containing composition of the kit (2), and the acid- and base-containing composition of the kit (3) contain a polyhydric alcohol and these compositions are in a gel or liquid form, the content of the polyhydric alcohol in these compositions is preferably 1% by mass or more, particularly 10% by mass or more, from the viewpoint of ease of use during use, and is preferably 90% by mass or less, particularly 80% by mass or less, and especially 70% by mass or less, from the viewpoint of containing other components to enhance the cosmetic effect as a skin topical agent. When the base-containing composition of the kit (1), the acid-containing composition of the kit (2), and the acid- and base-containing composition of the kit (3) are in a gel or liquid form, other components contained in these compositions include surfactants, preservatives, pH adjusters, fragrances, colorants, antioxidants, antibacterial and antifungal agents, etc.

When the base-containing composition of kit (1), the acid-containing composition of kit (2), or the acid- and base-containing composition of kit (3) is in a solid form, the following methods can be used to granulate the composition.

When granules are obtained by granulating a mixture of an acidic substance and/or a carbon dioxide gas generating substance with other components, the content of the other components is not particularly limited, but is preferably less than 95% by mass in the granules. If the other components are present in an amount exceeding 95% by mass, the foaming property is reduced, which is not preferred.
The method for producing the powder or granules is not limited to that in this embodiment, and they can be produced by a conventional method such as a dry crushing granulation method, a wet crushing granulation method, a fluidized bed granulation method, a high speed stirring granulation method, or an extrusion granulation method.

For example, in the production of granules, a matrix base material having a function such as granule molding may be used. When a low melting point compound is used as the matrix base material, the carbon dioxide gas generating substance is added to the low melting point compound that has been melted by heating in a container such as a beaker, and the mixture is thoroughly stirred and mixed. If necessary, suitable additives may be added to this. This is gradually cooled at room temperature while being further stirred, and left to stand until it solidifies. Once it has solidified to a certain extent, it may be rapidly cooled in a refrigerator, etc.

Also, for example, the above materials can be put into a fluidized bed granulator, mixed with an air current for several minutes, and then granulated by spraying water onto the mixture.

When a low-melting compound is not used as the matrix base, the granulating agent is dissolved or dispersed in a suitable solvent such as water or ethanol in a container such as a beaker, and the carbon dioxide gas generating substance is dissolved or dispersed in this and mixed thoroughly, and then the mixture is heated in an oven or the like to remove the solvent and dried. Once completely solidified, it is pulverized and sieved to make the particle size uniform, and then made into granules.

The shape of the acidic substance and/or carbon dioxide gas generating substance can be, for example, irregular, planar, polyhedral, spherical, teardrop-like, fibrous, cylindrical, fine powder, etc., without any particular restrictions. In addition, a wide range of particle sizes can be used without any particular restrictions. In particular, from the standpoint of ease of handling and ease of mixing with the viscous composition, a particle size distribution of about 1,000 μm or less is more preferable. The particle size distribution in the present invention can be determined by a conventional laser diffraction/scattering method.

The acidic substance and/or carbon dioxide gas generating substance may be blended directly with the components contained in the same agent, but may be blended so as not to come into physical contact with other components in the same agent and coexist. In this case, for example, a coating layer may be provided on either or both of the acidic substance and/or carbon dioxide gas generating substance and the other components, or either or both of the carbon dioxide gas generating substance and the other components may be encapsulated. In addition, the acidic substance and/or carbon dioxide gas generating substance may be compression molded by sandwiching a layer that does not contain the carbon dioxide gas generating substance, the acidic substance, and other components between each other component or between other components so that they do not come into direct contact with each other. Known methods can be used as a means for making the acidic substance and/or carbon dioxide gas generating substance and other components coexist in the same agent.

When the kits (1) to (3) are composed of water-containing compositions, the mixing ratio (mass ratio) of the two is preferably 1:0.1 to 20, and more preferably 1:0.2 to 10. When the kits (1) to (3) are composed of a water-containing composition and a composition that is substantially free of water (for example, a composition in which the proportion of water is 5% by mass or less), the mixing ratio (mass ratio) of the two is preferably 1:0.01 to 30, and more preferably 1:0.05 to 20.

The amounts of the acidic substance, carbon dioxide gas generating substance, thickener, water and specific component used in the topical skin preparation of the present invention (or used in mixing to obtain a carbon dioxide gas-containing topical skin preparation) are preferably 0.1 to 15% by mass for the acidic substance, 0.1 to 20% by mass for the carbon dioxide gas generating substance, 0.1 to 20% by mass for the thickener, 40 to 99.6% by mass for the water and 0.01 to 30% by mass for the specific component, relative to the total amount. Furthermore, when the topical skin preparation contains a polyhydric alcohol, the amounts of the acidic substance, carbon dioxide gas generating substance, thickener, water, specific component, and polyhydric alcohol used in the topical skin preparation (or used in mixing to obtain a carbon dioxide gas-containing topical skin preparation) are preferably 0.1 to 10% by mass for the acidic substance, 0.1 to 10% by mass for the carbon dioxide gas generating substance, 0.1 to 15% by mass for the thickener, 30 to 97% by mass for the water, 0.01 to 20% by mass for the specific component, and 0.05 to 50% by mass for the polyhydric alcohol, relative to the total amount. The amounts of these components can be obtained as the amounts in the kit for obtaining the topical skin preparation or the composition for the topical skin preparation, or as the amount of water to be mixed with the composition.

<Use form of the composition for external skin preparation>
The composition for skin external preparation of the present invention may be in any form such as solid, liquid, gel, etc., but in terms of ease of mixing with other agents and cost during production, a solid form is preferred, and among solid forms, granular, fine granular, and powder forms are more preferred. When using the composition for skin external preparation, foaming occurs by mixing with a water-containing substance on the palm of the hand or in a container. Examples of the water-containing substance used include water-containing liquids that are usually used in cosmetics, medicines, etc., or used in ordinary households. The water-containing liquid may be water itself. Specifically, examples include tap water, distilled water, membrane-filtered water, ion-exchanged water, deep sea water, as well as alcoholic beverages such as sake and wine, soy milk, drinking yogurt, acerola juice, sports drinks, carbonated water, rice water, etc. These may be used alone or in a mixture of two or more.

The amount of water-containing substance used is not particularly limited and can be used in a wide range, but for example, it is preferable to add 1 to 10 times the mass of the topical skin preparation, and more preferably 2 to 5 times the mass. By adding more than 1 time the amount of liquid, the topical skin preparation can be dissolved quickly and a sufficient amount of carbon dioxide gas can be generated. On the other hand, by adding up to 10 times the amount of liquid, dripping due to a decrease in the viscosity of the topical skin preparation can be prevented.

The temperature of the water-containing substance used is not particularly limited and can be in a wide range, but it is particularly preferable to cool it before use, as this will enhance the effect of carbon dioxide gas due to the action of specific components in the skin topical agent. From the viewpoint of the feel when applied and convenience for the user, it is preferable to use water or tap water at about room temperature.

When the skin topical preparation composition or the components of the kit are solids, there are no particular limitations on the method of storing the kit, so long as they are stored in a state that blocks moisture and does not come into contact with the skin. The shape of the storage container used can be appropriately selected depending on the purpose, and examples of the shape include cups, tubes, bags, bottles, sticks, pumps, jars, cans, etc. In addition, the material constituting the storage container can be, for example, plastic, glass, aluminum, paper, various polymers, etc., which can be used alone or in combination of two or more types, but is not limited to these.

Specific examples of containers that are preferable in terms of airtightness, storage stability of contents, manufacturing costs, etc. include aluminum sticks and aluminum bags whose inner surface is laminated with polyethylene terephthalate, stand-up pouches with zippers, and polyethylene terephthalate storage containers whose lids are heat-sealed with aluminum film whose inner surface is laminated with polyethylene terephthalate, etc.

<Uses of topical skin preparations>
The skin topical preparation of the present invention promotes an increase in skin blood flow due to the action of carbon dioxide gas. The skin topical preparation of the present invention has excellent skin-improving effects, such as whitening the skin color, increasing the skin moisture content, reducing the amount of water evaporation, and improving skin elasticity. In addition, the skin topical preparation of the present invention has excellent usability during use (ease of mixing, smoothness of foam, fineness of foam, uniformity of foam, ease of application, resistance to dripping, foam elasticity, carbonation and its duration, etc.), and excellent usability after use (skin moistness, elasticity, brightness, redness, smoothness, smoothness, tightening, etc.). In addition, the skin topical preparation of the present invention promotes skin metabolism (turnover). Furthermore, the skin topical preparation of the present invention contains a specific active ingredient in a carbon dioxide gas foaming skin topical preparation, and has a skin cell activating effect, and can be used as a skin cell activating agent. In addition, the skin topical preparation of the present invention has an activation effect on skin metabolism and an ATP production promoting effect due to cell activating effect. Taking advantage of these effects, the topical skin preparation of the present invention has the following properties: whitening, improving skin quality, improving freckles, rejuvenating the skin, tightening the skin, spot reducing, cleansing the skin, conditioning the skin, smoothing the skin texture, keeping the skin healthy, preventing rough skin, tightening the skin, moisturizing the skin, replenishing and maintaining the skin's moisture and oil content, maintaining the skin's flexibility, protecting the skin, preventing the skin from drying out, softening the skin, making the skin firm, making the skin lustrous, smoothing the skin, preventing age spots and freckles caused by sunburn, and reducing dryness. The present invention can be suitably used not only as a cosmetic intended to make fine wrinkles caused by aging less noticeable, but also as a quasi-drug or medicine such as medicine for preventing rough skin, chapped skin, heat rash, chilblains, cracks, chapped skin, acne, oily skin, razor burn, spots and freckles caused by sunburn, hot flashes after sunburn or snowburn, tightening the skin, cleaning the skin, conditioning the skin, keeping the skin healthy, moisturizing the skin, protecting the skin, preventing dryness of the skin, etc. The skin topical preparation of the present invention is preferably used as a cosmetic or quasi-drug, and is preferably used as a cosmetic or medicinal cosmetic such as a milky lotion, cream, pack agent, peeling agent, etc. Among them, it is particularly preferable to use it as a pack agent, since it is easy to obtain a good feeling of use and a high skin condition improving effect.

The present invention also provides a carbon dioxide gas foaming skin preparation for external use obtained by mixing an acidic substance, a carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas, a thickener, and water, and further provides a carbon dioxide gas foaming skin preparation for external use (carbon dioxide gas-containing composition) that contains the above-mentioned specific component.

The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. In each of the following examples and comparative examples, the raw materials used were commercially available products unless otherwise specified. The arbutin used below is β-arbutin.

<Production of foaming skin preparation>
The components shown in Tables 1 to 6 were mixed to obtain the compositions shown in the tables to produce skin topical preparation kits for each Example and Comparative Example. In each Example and Comparative Example shown in Tables 1 to 6, preparations not containing water were in powder form, preparations containing water and a thickener were in gel form, and preparations containing water but no thickener were in liquid form.
In addition, the components shown in Table 7 below were mixed to prepare a powdered composition for external use on the skin.
The skin topical preparations obtained by mixing the A and B agents of each Example shown in Tables 1 to 6 in the amounts shown in Tables 1 to 6 were easy to apply to the skin and easy to use. In addition, they provided a cosmetic effect to the skin after use. The same was true for a skin topical preparation obtained by mixing the composition for skin topical preparation shown in Table 7 with 9 g of the composition and 27 g of water as shown in Table 7. In Tables 1 to 7, an acidic substance is also simply called "acid", and a carbon dioxide gas generating substance is also simply called "carbonate". Glucose listed in "Other" also includes uses as a polyhydric alcohol.

The following [Evaluation 1] was carried out for each of the above examples and comparative examples.
[Evaluation 1]
Two healthy women in their 20s and 30s were randomly selected as subjects. The inside of the forearm of each subject was washed with a facial cleanser and allowed to rest for 15 minutes in a measurement room. Next, the color difference, water evaporation rate, stratum corneum moisture content, and elasticity were measured for a 4 cm x 4 cm measurement area on the inside of the forearm where the foaming skin topical agent was to be applied, using the following method. Next, the foaming skin topical agent was applied to the measurement site and left to stand for 10 minutes. Thereafter, the foaming skin topical agent was removed and washed with water. After 15 minutes had passed after washing, the same measurement was performed after using the foaming skin topical agent. The subjects rested in the measurement room during the measurement.
The results of measuring the skin condition after use are shown in Figures 1A to 13B. The values in Figures 1A to 13B are relative values (rate of change) when the measured value before use of the foaming topical skin preparation is set to 1. A larger value for color difference indicates a whiter skin color, a smaller value for water evaporation indicates a better result with a well-established barrier function, a larger value for stratum corneum moisture content indicates a better result, and a larger value for elasticity indicates a better result.

The skin condition before and after application of the foaming skin preparation was measured using the following devices, according to the standard method described in the instruction manual attached to each device.
Color difference: Measured with a color difference meter (CR-400 manufactured by Konica Minolta).
Water evaporation rate: Measured using a Tevameter (registered trademark) TM300 (CK Corporation).
Stratum corneum moisture content: Measured using a skin epidermal stratum corneum moisture content measuring device SKICON-200EX (manufactured by IBS Co., Ltd.) This skin epidermal stratum corneum moisture content measuring device evaluates the moisture content of the stratum corneum as skin conductance (electrical conductivity, unit: μS).
Elasticity: Measured using a skin viscoelasticity measuring device Cutometer MPA580 (manufactured by Courage+Khazaka).

As shown in Figures 1A to 13B, the foaming topical skin preparations of each Example containing a specific ingredient showed a greater increase in color difference, stratum corneum moisture content, and elasticity from before use, and a smaller decrease in water evaporation rate, compared to the foaming topical skin preparations of each Comparative Example that did not contain the specific ingredient. Therefore, it is clear that the foaming topical skin preparation of the present invention containing a specific ingredient has a high effect of improving skin conditions.

The following [Evaluation 2] was carried out for each of the above Examples and Comparative Examples.
[Evaluation 2]
Three healthy women in their 20s to 30s were randomly selected as subjects. The inside of the forearm of each subject was washed with a facial cleanser and allowed to rest for 15 minutes in a measurement room. Next, the foaming skin preparation was applied to the measurement site on the inside of the forearm and left to stand for 10 minutes. Next, the foaming skin preparation was removed and washed with water. Evaluation items (16 items) during and after use were evaluated based on a 7-level evaluation standard. The evaluation standard is shown in Table A below, and the results are shown in Tables B to G below. The results below are the average of the evaluation points of the three subjects.

As shown in Tables B to G, the foaming topical skin preparations of each Example containing a specific ingredient were superior in terms of feel during use (ease of mixing, smoothness of foam, fineness of foam, uniformity of foam, ease of application, resistance to dripping, foam elasticity, carbonation and its duration) and in terms of feel after use (skin moisture, elasticity, brightness, redness, smoothness, silky feeling, firmness). Therefore, it is clear that the foaming topical skin preparation of the present invention containing a specific ingredient has a high effect of improving skin condition, and can whiten, improve skin quality, tighten skin, condition skin, condition skin texture, firm skin, moisturize skin, maintain skin flexibility, soften skin, give skin firmness, smooth skin, and make fine wrinkles caused by dryness less noticeable.

The following [Evaluation 3] was carried out for each of the above Examples and Comparative Examples.
[Evaluation 3] (Turnover test)
The subject (a randomly selected healthy woman in her 20s to 30s) was washed with a facial cleanser on the inside of the forearm and allowed to rest for 15 minutes in the measurement room. Next, cellophane tape (4 cm x 1.8 cm) was applied to the measurement site on the inside of the forearm, and the tape was peeled off after being pressed with a certain pressure. The foaming skin topical agent after mixing was applied to the measurement site in an area of 4 cm x 4 cm and left to stand for 10 minutes. Next, the foaming skin topical agent was removed and washed with water. After 5 minutes, the tape was applied and peeled off twice at the measurement site other than the area where it was applied before application.
The first tape was discarded, and a thin layer of vinyl chloride resin adhesive was spread on the surface of the second tape from which the stratum corneum was collected, and the adhesive was attached to a glass slide. After application, the glass slide was thoroughly dried, then immersed in ethanol for 10 minutes, and then dried at room temperature (22°C to 27°C) for 10 minutes or more. The glass slide was then immersed in xylene until the tape peeled off. After the tape was peeled off, the glass slide was further immersed in xylene for 30 minutes to 1 hour. The glass slide was removed, dried, and then immersed in a staining solution (a solution of 0.1 w/w% gentian violet and 0.5 w/w% brilliant green dissolved in purified water) for 15 minutes. The glass slide was washed 4 to 5 times with purified water, dried, and observed under an optical microscope at 200x magnification. The obtained observation images were evaluated on a 5-point scale for each of the three items listed in Table H below, according to the evaluation criteria shown in Table H below. The total score (score: 5 to 1 point) for three items was calculated for the images observed before and after use of the foaming topical skin preparation, and the total score before use was subtracted from the total score after use to obtain a value. All three items in Table H below indicate the degree of skin metabolism (turnover), and the higher the score, the greater the degree of turnover. The difference in the total score obtained above before and after use is shown in Figures 14 to 26. Also, the images of stratum corneum cells before and after use of the foaming topical skin preparations of Comparative Example 1, Examples 1-19, Examples 2-3, and Examples 4-3 obtained by the above-mentioned microscopic observation are shown in Figure 27.

As shown in Figures 14 to 26, in each Example containing a specific ingredient, the total score after use of the foaming topical skin preparation increased by 2 or more from before use. On the other hand, in Comparative Examples 1 to 7, the total score after use of the foaming topical skin preparation decreased from before use, or if it increased, the difference from before use was only 1 or less. Also, from Figure 27, it is clear that the improvement in stratum corneum morphology and orderly arrangement, which are indicators of turnover, from before use after use of the foaming topical skin preparation was remarkable in the Examples, but not in the Comparative Examples. Therefore, it is clear that the foaming topical skin preparations of each Example are superior in the effect of promoting turnover compared to each Comparative Example.

The specific components used in the present invention were subjected to a cell activation test according to the following procedures (1) to (5).
[Cell activation test 1]
(1) Normal human dermal fibroblasts (NHDF) were cultured in a 75 ^cm flask in a 37°C, 5% by volume _CO incubator in Dulbecco's modified Eagle medium containing 10% by mass of fetal bovine serum (10% by mass FBS-DMEM).
(2) The cells cultured in (1) were suspended by trypsinization and then seeded from the 75 cm ² flask into each well of a 96-well plate at a cell density of 1×10 ⁴ cells/well.
(3) The cells seeded in (2) were pre-cultured in 10% by mass FBS-DMEM medium in a 5% by volume _CO2 incubator at 37°C for 24 hours.
(4) After the pre-culture in (3), the medium was removed from each well, and the wells were washed once with 200 μL/well of serum-free DMEM, and then 200 μL of a medium containing a test substance prepared to a predetermined concentration was added to each well. After addition of the medium containing the test substance, the cells were cultured in a 5% by volume _CO2 incubator at 37°C for 24 hours.
The test substance-containing medium was prepared according to Preparation Method 1 below.
(Preparation method 1 of test substance-containing medium)
Sodium bicarbonate, malic acid, a thickener shown in Table 8 below, and arbutin as a specific component were mixed with serum-free DMEM so that the final concentration of sodium bicarbonate was 62.5 mM, the final concentration of malic acid was 20.8 mM, and the final concentrations of the thickener and specific component were the values shown in Table 8 below.

(5) After culturing, the cells were washed once with 200 μL/well of PBS.
Cell Counting Kit-8 solution diluted 30-fold with serum-free DMEM was added at 150 μL/well, and then the plate was placed in a 5% _CO2 incubator at 37° C. to allow color to develop appropriately, and the absorbance at 450 nm was measured.
The cell activation activity (%) was calculated based on the obtained absorbance using the following formula. In the following formula, the data of Reference Example 1 was used as the data control. Cell activation activity (%)=(Data sample-Data blank)/(Data control-Data blank)×100

The results of cell activation activity are shown in Figure 28. As shown in Figure 28, it can be seen that the cell activation activity can be increased by combining a specific component with a thickener, an acidic component, and a carbon dioxide gas generating component.

In addition, the specific components shown in Table 9 below were subjected to the following [Cell Activation Test 2].
[Cell activation test 2]
The preparation method of the medium containing the test substance was changed to the following Preparation Method 2. In addition, when calculating the cell activation activity (%), serum-free DMEM containing no test substance was used as a data control. Other than these points, the same procedure as in the above [Cell Activation Test 1] was followed. The results are shown in Table 9 below.
(Method 2 for preparing a medium containing a test substance)
The specific components shown in Table 9 below were mixed with serum-free DMEM to give final concentrations shown in Table 9 below. When the "carbonate" column in Table 9 below reads "present," both the specific components were mixed with serum-free DMEM to give final sodium bicarbonate concentrations of 31.2 mM and final malic acid concentrations of 6.25 mM. When the "carbonate" column in Table 9 below reads "-," only the specific component was mixed with serum-free DMEM, and neither sodium bicarbonate nor malic acid was used.

As described above, it has been confirmed that the cell activation activity of foaming skin topical preparations containing specific ingredients is enhanced.

Claims (2)

A one-component foaming skin preparation for external use that contains an acidic substance, a carbonate, and a thickener, and further contains at least one selected from ascorbic acid-2-glucoside and tranexamic acid, and is characterized in that the foaming skin preparation for external use is mixed with a water-containing substance when used. The foamable skin topical preparation according to claim 1, which promotes cell turnover or stimulates cell activity.