Foamable skin external preparation

Abstract

To provide a foamable skin external preparation which has good use feeling and is effective for improving skin conditions.SOLUTION: There is provided a foamable skin external preparation having at least a solid acid substance and a solid carbon dioxide generating substance which generates carbon dioxide by reacting with the acid substance, which further contains at least one selected from a cellulose derivative and a starch derivative as a polysaccharide or a derivative thereof and at least one selected from a hydrophilic natural polymer which is alginic acid or a salt thereof, carrageenan, guar gum, locust bean gum, xanthan gum or tamarind gum (provided that alginic acid or a salt thereof is excluded when sodium carboxymethyl cellulose is contained as a cellulose derivative), in which the skin external preparation is mixed with a water-containing substance when used.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an external preparation for skin. [Background technology]

[0002] 2. Description of the Related Art External skin preparations containing synthetic or natural extracts or the like having a blood circulation promoting effect on the skin have been used in the past.

[0003] 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. Many of these generate carbon dioxide gas by the reaction of an acidic substance with a carbon dioxide gas generating substance. As for the dosage form of these external skin preparations, one in which the acidic substance and the carbon dioxide gas generating substance are separate agents and mixed together at the time of use to generate foam is known, in order to maintain the carbon dioxide generating ability of the external skin preparation for a long period of time (Patent Documents 1 and 2). In contrast to these, external skin preparations are also known which contain an acidic substance and a carbon dioxide gas generating substance, and which are mixed with a viscous composition containing water and a thickener when used (Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 63-310807 [Patent Document 2] Japanese Patent Application Publication No. 05-229933 [Patent Document 3] WO99 / 24043 publication Summary of the Invention [Problem to be solved by the invention]

[0005] A foaming skin preparation for external use of the type which contains an acidic substance and a carbon dioxide gas generating substance and is mixed with a water-containing substance when used has the advantage that it is easy to handle when made into a one-component formulation. However, conventional topical skin preparations of this type have been insufficient in terms of achieving both ease of use, such as ease of mixing and application when mixed with a water-containing substance, and an effect of improving skin condition, such as improving the skin's moist feeling, elasticity, brightness, etc. [Means for solving the problem]

[0006] The present invention relates to a foamable skin preparation for external use, which comprises at least a solid acidic substance and a solid carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas, and further comprises: As the polysaccharide or its derivative, at least one selected from a cellulose derivative and a starch derivative; At least one selected from the group consisting of alginic acid or its salts, carrageenan, guar gum, locust bean gum, xanthan gum, and tamarind gum (however, in the case where sodium carboxymethylcellulose is contained as the cellulose derivative, alginic acid or its salts are excluded), The present invention provides a foaming external preparation for skin which is mixed with a water-containing substance when used.

[0007] The present invention also provides a foamable skin preparation for external use, which comprises at least a solid acidic substance and a solid carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas, and further comprises: The polysaccharide or its derivative contains two or more kinds selected from hydrophilic natural polymers, which are alginic acid or its salts, carrageenan, guar gum, locust bean gum, xanthan gum, and tamarind gum; The present invention provides a foaming external preparation for skin which is mixed with a water-containing substance when used.

[0008] The present invention also provides a foamable skin preparation for external use, which comprises at least a solid acidic substance and a solid carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas, and further comprises: The polysaccharide or its derivative contains two or more selected from cellulose derivatives and starch derivatives, The present invention provides a foaming external preparation for skin which is mixed with a water-containing substance when used.

[0009] The present invention also provides a foamable skin preparation for external use, which comprises at least a solid acidic substance and a solid carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas, and further comprises: At least one polysaccharide or derivative thereof; At least one of an inorganic hydrophilic thickening compound and an organic thickening agent, which is a hydrophilic synthetic polymer, The present invention provides a foaming external preparation for skin which is mixed with a water-containing substance when used. Effect of the Invention

[0010] According to the present invention, it is possible to provide an external skin preparation which has a good feel when used and is effective in improving the condition of the skin. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a graph showing the rate of change in L* value (whiteness) in the examples and comparative examples. [Diagram 2] FIG. 2 is a graph showing the rate of change in stratum corneum moisture content in the examples and comparative examples. [Diagram 3] FIG. 3 is a graph showing the rate of change in elasticity in the examples and comparative examples. [Figure 4] FIG. 4 is a graph showing the foaming amount (volume increase rate of a mixture of an external skin preparation and a water-containing substance) in Examples and Comparative Examples. [Diagram 5] FIG. 5 is a graph showing the amount of carbon dioxide gas generated in the examples and the comparative examples. [Figure 6] FIG. 6 is a graph showing the rate of change in water evaporation rate in the examples. [Figure 7] FIG. 7 is a graph showing the rate of change in stratum corneum moisture content in another example. [Figure 8] FIG. 8 is a graph showing the rate of change of the L* value in another example. [Figure 9]FIG. 9 is a graph showing the rate of change in stratum corneum moisture content in another example. [Figure 10] FIG. 10 is a graph showing the rate of change of elasticity in another embodiment. [Figure 11] FIG. 11 is a graph showing the rate of change in water evaporation rate in another example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The skin external preparation of the present invention contains at least a solid acidic substance and a solid carbon dioxide gas generating substance that reacts with the acidic substance to generate carbon dioxide gas.

[0013] The skin external preparation of the present invention is used by a user who, when using the skin external preparation, mixes the skin external preparation with a water-containing substance to generate carbon dioxide gas to generate foaming, and then applies the mixture to the skin. Each of the components contained in the skin external preparation and the method for producing the same will be described below.

[0014] <Solid acidic substances> The solid 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. In addition, any solid form may be used, but a powder form such as granules or powder is preferred, and a powder form is particularly preferred.

[0015] Examples of 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, and sulfamic acid.

[0016] Examples of organic acids include straight-chain fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid; 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; acidic amino acids such as glutamic acid and aspartic acid; and 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.

[0017] Among these, citric acid, ascorbic acid, malic acid and succinic acid are preferred from the viewpoints of safety and solubility in water.

[0018] The content of the solid acidic substance in the topical skin preparation of the present invention is preferably from 1% by mass to 20% by mass, more preferably from 2% by mass to 18% by mass.

[0019] <Solid carbon dioxide generating material> As the solid carbon dioxide gas generating substance used in the present invention, which reacts with the acidic substance to generate carbon dioxide, various substances can be used without any particular limitation. In addition, any form of formulation may be used as long as it is solid, but powder forms such as granules and powders are preferred, and powder forms are particularly preferred.

[0020] Examples of the carbon dioxide gas generating substance include carbonates such as sodium carbonate, calcium carbonate, potassium carbonate, magnesium carbonate, and sodium sesquicarbonate, and hydrogen carbonates such as ammonium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, magnesium hydrogen carbonate, and calcium hydrogen carbonate, and one or more of these are used. Among these, hydrogen carbonates are preferably used, and sodium hydrogen carbonate is more preferred in that it can realize a suitable foaming power.

[0021] The content of the carbon dioxide gas generating substance in the external skin preparation of the present invention is preferably from 1% by mass to 30% by mass, more preferably from 2% by mass to 25% by mass.

[0022] <Polysaccharides or their derivatives> Examples of polysaccharides or derivatives thereof used in the present invention include various polysaccharides that can be used in the fields of cosmetics and pharmaceuticals. Specific examples of polysaccharides include xanthan gum, succinoglycan, carrageenan, guar gum, locust bean gum, galactan, gum arabic, tragacanth gum, tamarind gum, agar, agarose, mannan, hyaluronic acid and its salts, chondroitin sulfate and its salts, curdlan, pectin, alginic acid and its salts, starch, dextrin, celluloses, and other hydrophilic natural polymers; starch derivatives such as carboxymethyl starch and its salts, acrylic acid grafted starch and its salts, hydroxypropyl cellulose and its derivatives, hydroxyethyl cellulose and its derivatives, hydroxypropyl methyl cellulose, hyaluronic acid and its salts, chondroitin sulfate ... Hydrophilic synthetic polymers such as derivatives of hydroxypropylmethylcellulose, such as hydroxypropylmethylcellulose phthalate and hydroxypropylmethylcellulose having a hydrocarbon group such as stearyl group, sulfonated cellulose derivatives, carboxymethylcellulose and its derivatives and their salts, carboxymethylethylcellulose and its salts, cellulose acetate phthalate, cationic cellulose such as O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethylcellulose chloride (also called "polyquaternium-10"), ethylcellulose, chlorocarmellose and its salts, and other cellulose derivatives. These can be used alone or in combination of two or more. As exemplified above, the starch derivative in this specification does not include dextrin. In addition, examples of the above salts include sodium salts, potassium salts, calcium salts, and the like. Examples of derivatives of hydroxypropyl cellulose include hydroxypropyl cellulose acetate and hydroxypropyl cellulose propionate. Examples of derivatives of hydroxyethyl cellulose include hydroxyethyl cellulose acetate, hydroxyethyl cellulose propionate and polyquaternium-67. Examples of derivatives of carboxymethyl cellulose include carboxymethyl cellulose acetate, carboxymethyl cellulose propionate and methylamide cellulose gum.

[0023] In addition, it is preferable to use polysaccharides or derivatives thereof that have high solubility and / or dispersibility in water, because when the skin topical preparation of the present invention is mixed with a water-containing substance, it can be dissolved and / or dispersed uniformly without forming lumps, and the rough feeling of the skin caused by the undissolved components can be alleviated. Here, the solubility and dispersibility in water can be judged based on whether the skin topical preparation is dissolved or dispersed uniformly in a short time when water at about room temperature is added and stirred, and whether or not lumps are formed when dissolved.

[0024] From the viewpoint of the above-mentioned solubility and dispersibility in water, preferred examples of polysaccharides or derivatives thereof include xanthan gum, succinoglycan, carrageenan, guar gum, locust bean gum, galactan, gum arabic, tragacanth gum, tamarind gum, agar, agarose, mannan, hyaluronic acid and its salts, curdlan, alginic acid and its salts, starch and its derivatives, dextrin, cellulose and cellulose derivatives, etc.

[0025] Although only one type of polysaccharide or derivative thereof may be used in the present invention, it is preferable to use two or more types in combination for the following reasons. Most of the polysaccharides or their derivatives dissolve or disperse in water to provide a thickening effect. In addition, adding polysaccharides or their derivatives to a skin external preparation has the advantage of improving the stability of the skin external preparation before use and during storage, and preventing the reaction between acid and carbon dioxide gas generating substances to prevent the generation of carbon dioxide gas. Among polysaccharides or their derivatives, there are those that contribute more to the thickening effect than to the stability during storage (hereinafter also referred to as type A polysaccharides or their derivatives), and those that contribute more to the stability during storage than to the thickening effect (hereinafter referred to as type B polysaccharides or their derivatives). Therefore, by combining both types of polysaccharides or their derivatives, it is possible to improve both the thickening effect and the stability during storage. Examples of type A polysaccharides or their derivatives include xanthan gum, carrageenan, hyaluronic acid, and cellulose and its salts or derivatives, and examples of type B polysaccharides or their derivatives include starch or its derivatives and dextrin as preferred polysaccharides. By using type B polysaccharides or their derivatives, the generation of carbon dioxide gas during storage of the skin external preparation can be suppressed. In particular, the use of starch or its derivatives is preferable because it effectively suppresses the generation of carbon dioxide gas and further improves the long-term storage stability. When starch or its derivatives are used in the present invention, the preferred amount of starch or its derivatives is 3% by mass or more, particularly 5% by mass or more, and especially 10% by mass or more in the skin external preparation. In the present invention, it is preferable to use many types of polysaccharides or derivatives thereof, for example, to combine three or more types.

[0026] Furthermore, as is clear from the examples described below, for example, a comparison between Examples 1 and 2, the present inventors have found that when two or more kinds of polysaccharides or derivatives thereof are used in combination, the carbon dioxide gas retention capacity of the skin topical agent (mixture) when mixed with a water-containing substance is high, the mixture applied to the skin is less likely to drip, the effects of improving the skin condition such as reducing redness and improving elasticity are easily obtained, and the feel of use including ease of application and removal is improved, etc. Furthermore, as is clear from Examples 6 to 10, the inventors have found that these effects are higher in the presence of an extract containing a water-soluble protein and / or a natural surfactant, particularly saponin.

[0027] In the present invention, the content of polysaccharides or derivatives thereof in the skin external preparation is preferably 8% by mass or more and 50% by mass or less, more preferably 11% by mass or more and 45% by mass or less. The content of polysaccharides or derivatives thereof is preferably 8% by mass or more and 50% by mass or less from the viewpoint of handling during use, particularly from the viewpoint of easy mixing with a water-containing substance and less dripping during use. If it is less than 8% by mass, it is likely to drip during use, and if it exceeds 50% by mass, it is difficult to mix when mixed, and it immediately thickens after mixing with a water-containing substance, making it difficult to apply to the use site, which is not preferable.

[0028] Furthermore, when a type A polysaccharide or derivative thereof is used in combination with a type B polysaccharide or derivative thereof as the polysaccharide or derivative thereof, the mass ratio of the two is preferably 10 parts by mass or more and 1,000 parts by mass or less, and more preferably 20 parts by mass or more and 800 parts by mass or less, of the polysaccharide or derivative thereof B per 100 parts by mass of the polysaccharide or derivative thereof A.

[0029] The inventors have further discovered that when the topical skin preparation of the present invention contains two or more types of polysaccharides or derivatives thereof in any of the following (1) to (3), the effect of the present invention, that is, "good sensation upon use and improvement of skin condition", is remarkable. (1) The composition contains at least one selected from cellulose derivatives and starch derivatives, and at least one selected from hydrophilic natural polymers, which are alginic acid or its salts, carrageenan, guar gum, locust bean gum, xanthan gum, and tamarind gum (however, when sodium carboxymethylcellulose is contained as the cellulose derivative, alginic acid and its salts are excluded). (2) When the polysaccharide or its derivative contains two or more types of hydrophilic natural polymers selected from alginic acid or its salts, carrageenan, guar gum, locust bean gum, xanthan gum, or tamarind gum. (3) When the polysaccharide or its derivative contains two or more types selected from cellulose derivatives and starch derivatives.

[0030] Hereinafter, the hydrophilic natural polymer, which is alginic acid or a salt thereof, carrageenan, guar gum, locust bean gum, xanthan gum, or tamarind gum, may be simply referred to as a "specific hydrophilic natural polymer".

[0031] First, case (1) will be explained. In the case of (1), as an embodiment containing two or more types of polysaccharides or derivatives thereof, the following embodiment (a) or (b) is preferred from the viewpoint of more reliably enhancing the effect of the present invention, namely, "good feeling when used and improvement of skin condition." (a) as a cellulose derivative, at least one selected from hydroxyethyl cellulose and its derivatives, carboxymethyl cellulose and its derivatives and their salts, hydroxypropyl methyl cellulose and its derivatives, sulfonated cellulose derivatives, carboxymethyl ethyl cellulose and its salts, cellulose acetate phthalate, cationized cellulose, ethyl cellulose, and croscarmellose and its salts, or / and Contains starch derivatives.

[0032] (b) The composition contains at least one cellulose derivative selected from hydroxypropyl cellulose and its derivatives, and at least one hydrophilic natural polymer selected from alginic acid and its salts, carrageenan, guar gum, xanthan gum, and tamarind gum.

[0033] In the case of (1), particularly preferred embodiments containing two or more kinds of polysaccharides or derivatives thereof include any one of the following cases (a) to (c). (A) The composition contains, as a cellulose derivative, at least one selected from hydroxypropylmethylcellulose and its derivatives, and cationic cellulose, and / or contains, as a starch derivative, at least one selected from carboxymethylstarch and its salts, and acrylic acid-grafted starch and its salts. (i) The composition contains at least one cellulose derivative selected from hydroxyethyl cellulose and its derivatives, and at least one hydrophilic natural polymer selected from alginic acid and its salts, carrageenan, guar gum, locust bean gum, and tamarind gum. (c) The composition contains at least one cellulose derivative selected from carboxymethylcellulose and its derivatives and salts thereof, and at least one hydrophilic natural polymer selected from carrageenan, guar gum, locust bean gum, and tamarind gum.

[0034] In the case of (1), particularly preferred embodiments containing two or more kinds of polysaccharides or derivatives thereof include those containing any of the following combinations of polysaccharides or derivatives thereof: A combination of at least one selected from hydroxypropylmethylcellulose and its derivatives and at least one selected from alginic acid and its salts, and xanthan gum; A combination of cationic cellulose and tamarind gum; Starch derivatives in combination with tamarind gum; A combination of at least one selected from hydroxyethyl cellulose and its derivatives with at least one selected from alginic acid and its salts, and carrageenan; A combination of at least one selected from carboxymethylcellulose, its derivatives, and salts thereof, and at least one selected from carrageenan and guar gum.

[0035] As in the above case (1), when a cellulose derivative or starch derivative is combined with a specific hydrophilic natural polymer, the amount of the specific hydrophilic natural polymer relative to 100 parts by mass of the cellulose derivative or starch derivative is preferably 1 part by mass or more and 10,000 parts by mass or less in order to more reliably obtain the effects of the present invention. From this viewpoint, the amount of the specific hydrophilic natural polymer relative to 100 parts by mass of the cellulose derivative or starch derivative is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 5,000 parts by mass or less, and particularly preferably 10 parts by mass or more and 1,000 parts by mass or less. Note that the amount of the cellulose derivative or starch derivative referred to here is the total amount when the skin external preparation contains a cellulose derivative and a starch derivative. The amount of the cellulose derivative, starch derivative, and hydrophilic natural polymer referred to here can be the amount of the specific type of cellulose derivative, starch derivative, and hydrophilic natural polymer when the skin external preparation of the present invention contains a specific type of cellulose derivative, starch derivative, and hydrophilic natural polymer. Similarly, the amounts of the cellulose derivatives, starch derivatives, and hydrophilic natural polymers mentioned below can be the amounts of the specific types of cellulose derivatives, starch derivatives, and hydrophilic natural polymers when the topical skin preparation of the present invention contains specific types of cellulose derivatives, starch derivatives, and hydrophilic natural polymers.

[0036] In both the case of (1) and the cases of (2) to (4) below, the proportion of the total amount of the cellulose derivative, starch derivative, and specific hydrophilic natural polymer in the topical skin preparation is preferably 5% by mass or more in order to enhance the effects of the present invention, and is preferably 50% by mass or less in order to ensure the amounts of the acidic substance and carbon dioxide gas generating substance, prevent a decrease in the foaming property of the topical skin preparation of the present invention, and ensure functionality such as the feel when used and the effect of improving skin condition, etc. From this viewpoint, the proportion of the total amount of the cellulose derivative, starch derivative, and specific hydrophilic natural polymer in the topical skin preparation is more preferably 10% by mass or more and 45% by mass or less, and particularly preferably 12% by mass or more and 45% by mass or less.

[0037] Next, the case of (2) will be described. In the above case of (2), the skin external preparation contains, as the polysaccharide or its derivative, two or more selected from hydrophilic natural polymers, which are alginic acid or its salts, carrageenan, guar gum, locust bean gum, xanthan gum, and tamarind gum. In this case, from the viewpoint of making the effect of the present invention, "good feeling in use and improving the skin condition", even more remarkable, it is particularly preferable that the combination of two or more specific hydrophilic natural polymers is any one of the following (A) to (C).

[0038] (A) A combination of alginic acid or a salt thereof and at least one selected from carrageenan, guar gum, locust bean gum, and tamarind gum. (B) A combination of carrageenan and at least one selected from alginic acid and its salts, guar gum, xanthan gum, and tamarind gum. (C) A combination of two or more selected from guar gum, locust bean gum, xanthan gum and tamarind gum.

[0039] Particularly preferred combinations in the case where two or more specific hydrophilic natural polymers are contained include any of the following (A)' to (C)'. (A)' A combination of alginic acid or a salt thereof and at least one selected from carrageenan and tamarind gum; (B)' A combination of carrageenan and at least one selected from xanthan gum and tamarind gum; (C)' A combination of tamarind gum and at least one selected from guar gum and xanthan gum.

[0040] As in (2), when the polysaccharide or derivative thereof contains two or more kinds selected from hydrophilic natural polymers selected from alginic acid or its salts, carrageenan, guar gum, locust bean gum, xanthan gum, or tamarind gum, the content of any one of the other kinds per 100 parts by mass of one of the polysaccharides or derivatives is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 5,000 parts by mass or less, and particularly preferably 10 parts by mass or more and 1,000 parts by mass or less.

[0041] In the case of (A), the content of at least one selected from carrageenan, guar gum, locust bean gum, and tamarind gum per 100 parts by mass of alginic acid or a salt thereof is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 5,000 parts by mass or less, and particularly preferably 10 parts by mass or more and 1,000 parts by mass or less. In the case of (B), the content of at least one selected from alginic acid and its salts, guar gum, xanthan gum, and tamarind gum per 100 parts by mass of carrageenan is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 5,000 parts by mass or less, and particularly preferably 10 parts by mass or more and 1,000 parts by mass or less. In addition, the term "content of at least one type" as used herein means the total amount when there are two or more types. In the case of (C), the total amount of the other three gums per 100 parts by mass of one gum selected from guar gum, locust bean gum, xanthan gum, and tamarind gum is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 5,000 parts by mass or less, and particularly preferably 10 parts by mass or more and 1,000 parts by mass or less.

[0042] In the case of (2), the proportion of the total amount of the specific natural hydrophilic polymers in the topical skin preparation is preferably 5% by mass or more in order to enhance the effects of the present invention, and is preferably 50% by mass or less in terms of ensuring the amounts of acidic substances and carbon dioxide gas generating substances, preventing a decrease in the foaming properties of the topical skin preparation of the present invention, and ensuring the functionality of the topical skin preparation of the present invention, such as the feel of use and the skin condition improving effect, etc. From this viewpoint, the proportion of the total amount of the specific natural hydrophilic polymers in the topical skin preparation is more preferably 10% by mass or more and 45% by mass or less, and particularly preferably 12% by mass or more and 45% by mass or less.

[0043] Next, the case where (3) the polysaccharide or its derivative contains two or more kinds selected from cellulose derivatives and starch derivatives will be described.

[0044] In the case of (3), from the viewpoint of making the effects of the present invention even more reliably remarkable, it is preferable to contain (i) at least one selected from cellulose derivatives in combination with at least one selected from starch derivatives, or (ii) two or more specific cellulose derivatives in combination.

[0045] In the case of (i), for example, it is particularly preferable to contain, as the cellulose derivative, at least one selected from hydroxyethyl cellulose and its derivatives, hydroxypropyl methyl cellulose and its derivatives, sulfonated cellulose derivatives, carboxymethyl cellulose and its derivatives, and salts thereof, carboxymethyl ethyl cellulose and its salts, cellulose acetate phthalate, cationized cellulose, ethyl cellulose, and croscarmellose and its salts in combination with, as the starch derivative, at least one selected from carboxymethyl starch and its salts, and acrylic acid grafted starch and its salts. In the case of (a), it is particularly preferable to use, as the cellulose derivative, at least one selected from carboxymethyl cellulose and its derivatives, and salts thereof.

[0046] As the case of (b), for example, the following cases (X) and (Y) are preferable examples. (X) The cellulose derivative contains at least one selected from hydroxypropylmethylcellulose and its derivatives, and at least one selected from hydroxyethylcellulose and its derivatives, and cationized cellulose. (Y) The cellulose derivative contains at least one selected from carboxymethyl cellulose and its derivatives, and salts thereof, and at least one selected from hydroxyethyl cellulose and its derivatives, hydroxypropyl cellulose and its derivatives, sulfonated cellulose derivatives, carboxymethylethyl cellulose and its salts, cellulose acetate phthalate, cationized cellulose, ethyl cellulose, and croscarmellose and its salts.

[0047] When the topical skin preparation contains two or more types of polysaccharides or derivatives thereof selected from cellulose derivatives and starch derivatives, as in (3), the content of any one of the other types per 100 parts by mass of one of the polysaccharides or derivatives is preferably from 1 part by mass to 10,000 parts by mass, more preferably from 5 parts by mass to 5,000 parts by mass, and particularly preferably from 10 parts by mass to 1,000 parts by mass. Furthermore, when the topical skin preparation contains a combination of at least one selected from cellulose derivatives and at least one selected from starch derivatives, as in (i), from the viewpoint of making the effects of the present invention even more pronounced, it preferably contains from 1 to 10,000 parts by mass of starch derivative per 100 parts by mass of cellulose derivative, more preferably from 5 to 5,000 parts by mass, and particularly preferably from 10 to 1,000 parts by mass.

[0048] Furthermore, when the topical skin preparation contains at least one type (the former) selected from hydroxypropyl methylcellulose and its derivatives, and at least one type (the latter) selected from hydroxyethyl cellulose and its derivatives, and cationized cellulose, like (X) in (ii), it preferably contains a total amount of the latter per 100 parts by mass of the former in an amount of 1 to 10,000 parts by mass, more preferably 5 to 5,000 parts by mass, and particularly preferably 10 to 1,000 parts by mass.

[0049] Furthermore, when the topical skin preparation contains, as the cellulose derivative, at least one type (the former) selected from carboxymethyl cellulose and its derivatives, and their salts, and at least one type (the latter) selected from hydroxyethyl cellulose and its derivatives, hydroxypropyl cellulose and its derivatives, sulfonated cellulose derivatives, carboxymethyl ethyl cellulose and its salts, cellulose acetate phthalate, cationic cellulose, ethyl cellulose, and croscarmellose and its salts, like (Y) in (ii), the total amount of the latter per 100 parts by mass of the former is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 5 parts by mass or more and 5,000 parts by mass or less, and particularly preferably 10 parts by mass or more and 1,000 parts by mass or less.

[0050] In the case of (3), the proportion of the total amount of the cellulose derivative and the starch derivative in the topical skin preparation is preferably 5% by mass or more in order to enhance the effects of the present invention, and is preferably 50% by mass or less in order to ensure the feel of the topical skin preparation of the present invention when used and its functionality such as skin condition improving effect, etc. From this viewpoint, the proportion of the total amount of the cellulose derivative and the starch derivative in the topical skin preparation is more preferably 10% by mass or more and 45% by mass or less, and particularly preferably 12% by mass or more and 45% by mass or less.

[0051] The skin topical preparation of the present invention, which employs any one of the following configurations (1) to (3), suppresses the amount of water evaporation from the skin after use compared to before use, as compared to when a conventional combination of polysaccharides or their derivatives is employed. Or / and, the whiteness, skin moisture content and / or elasticity are increased after use compared to before use. As a result, the skin condition, such as moist feeling, elasticity, brightness, redness, smoothness and / or silkiness of the skin, is improved. Moreover, when the topical skin preparation of the present invention adopts any one of the following configurations (1) to (3), the effect is characterized in that in addition to obtaining the above-mentioned effect of improving the skin condition, the feeling of use is greatly improved. When the topical skin preparation of the present invention adopts the following configurations (1) to (3), it has all the properties required for a topical skin preparation that is mixed with a water-containing substance and foamed, such as ease of mixing, ease of dissolving, ease of application, resistance to dripping, and / or ease of removal, compared to when a combination of conventional polysaccharides or their derivatives is adopted. Furthermore, when the skin topical preparation of the present invention has the following constitutions (1) to (3), it has smooth foam, fine foam, no roughness, foam elasticity, foam retention, and high carbonation feeling and / or high long-lasting carbonation feeling. Therefore, the skin topical preparation of the present invention has a significantly improved usability compared to the case where a combination of conventional polysaccharides or their derivatives is used. Furthermore, the external skin preparation of the present invention, which has a highly sustained carbonation sensation, also provides a strong feeling of tightening to the skin. By obtaining these effects, the skin topical preparation of the present invention, when having any one of the following configurations (1) to (3), exhibits a remarkable effect of "feeling good when used and improving the condition of the skin." The effect of the present invention is obtained by the agent of the present invention containing a specific combination of polysaccharides or derivatives thereof (1) to (3) together with a solid acidic substance and a solid carbon dioxide gas generating substance. Therefore, for example, it cannot be obtained by an agent in which one or both of the combinations (1) to (3) are contained together with water to form a viscous composition, and this viscous composition is mixed with a solid acidic substance and / or a solid carbon dioxide gas generating substance when used.

[0052] It is more preferable that the skin external preparation of the present invention contains a water-soluble protein. Here, the water-soluble protein refers to a protein obtained by concentrating, separating, and purifying animal or vegetable proteins, which has the property of being easily dispersed or dissolved in water or various liquids. Specifically, when added at 5% by mass or more to water at 25°C under 1 atmosphere, it is a protein that can be uniformly dispersed or dissolved without forming lumps. The water-soluble protein includes a protein hydrolysate. As the hydrolysate, a protein derived from various organisms such as animals and fish is preferably hydrolyzed by alkali treatment or enzyme treatment. Specific water-soluble proteins that can be used include casein, collagen, hydrolyzed collagen such as gelatin, albumin, elastin, keratin, sericin, etc. These can be used alone or in combination of two or more. Among them, the skin external preparation of the present invention preferably contains albumin, collagen, and hydrolyzed collagen as the water-soluble protein. The water-soluble protein also serves as a foaming assistant, and in particular has the function of increasing the strength of bubbles and keeping the foam stable for a long period of time. Therefore, the addition of a water-soluble protein contributes to the ease of adjusting the viscosity of the skin topical preparation, the improvement of its solubility in water, and the increase in the amount of carbon dioxide generated, and is likely to improve the skin condition improving effect. The present inventors have found that the effect of the water-soluble protein is excellent by containing a polysaccharide or a derivative thereof, particularly two or more kinds of polysaccharides or derivatives thereof.

[0053] In addition, the skin external preparation of the present invention may contain only one water-soluble protein, but it is also preferable to contain two or more water-soluble proteins. This is shown, for example, in the comparison of Examples 13 and 14 and Example 17 described later. As is clear from these Examples, compared with the case where only albumin is contained as a water-soluble protein, the skin quality improving effect such as moist feeling and smoothness of the skin after use, and the use feeling of the mixture obtained by mixing the skin external preparation with a water-containing substance are easily improved when collagen or hydrolyzed collagen is contained together with albumin. In particular, when the foaming topical skin preparation of the present invention contains hydrolyzed collagen, the ease of application, the pleasant feeling when applied, and the good appearance are easily improved, as will be apparent from Example 14 described later. Furthermore, as will be apparent from a comparison between Examples 18 and 19 described later, even when used alone, hydrolyzed collagen has a high effect equal to or greater than that of albumin in retaining carbon dioxide in a mixture of the topical skin preparation and a water-containing substance, and in improving the skin condition after use of the topical skin preparation.

[0054] When the skin topical preparation of the present invention contains a water-soluble protein, the water-soluble protein is preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass to 8% by mass in the skin topical preparation. When the water-soluble protein is 0.01% by mass to 10% by mass, the strength of the bubbles containing the water-soluble protein is increased, and the effect of keeping the foam stable for a long period of time can be easily obtained.

[0055] Furthermore, when the topical skin preparation contains a water-soluble protein, from the viewpoint of further increasing the carbon dioxide gas retention ability when the topical skin preparation of the present invention is dissolved in water, the content of the water-soluble protein is preferably 0.1 part by mass or more, and more preferably 1 part by mass or more and 50 parts by mass or less, per 100 parts by mass of the polysaccharide or its derivative.

[0056] The skin external preparation of the present invention may contain various ingredients other than the solid acidic substance, the solid carbon dioxide gas generating substance, the polysaccharide or its derivative, and the water-soluble protein, depending on the application or purpose. Such ingredients are described in further detail below.

[0057] The skin external preparation of the present invention is preferably made of a surfactant such as a nonionic surfactant, an anionic surfactant, a cationic surfactant, or an amphoteric surfactant, from the viewpoint of retention of generated foam. In this case, the surfactant used is preferably a water-free solution, solid, flake, granule, fine granule, or powder from the viewpoint of storage stability, and is preferably a solid, flake, granule, fine granule, or powder. The above-mentioned surfactant is preferably a natural surfactant. The natural surfactant refers to a surfactant derived from animals and plants, and examples thereof include phospholipids such as lecithin, lanolin, cholesterol, saponin, sphingolipid, pectin, dipotassium glycyrrhizinate, and plant-extracted amino acid surfactants. The skin external preparation of the present invention preferably contains a natural surfactant in an amount of 0.001% by mass or more and 10% by mass or less, and more preferably contains a natural surfactant in an amount of 0.005% by mass or more and 8% by mass or less.

[0058] Among the above-mentioned natural surfactants, phospholipids, saponin, pectin, glycyrrhizic acid or a salt thereof are preferred, and those containing saponin-containing extracts and / or glycyrrhizic acid or a salt thereof are particularly preferred. Saponin is a glycoside that is widely distributed in plants, and is a general term for a group of compounds that have steroids or triterpenoids as the non-sugar moiety. Depending on the type of aglycone (non-sugar moiety of the glycoside), they can be broadly classified into triterpenoid saponins and steroid saponins. A common property of saponins is that their aqueous solutions have high foaming properties.

[0059] As described above, saponin is known to have foaming properties. The present inventors have found that adding an extract containing this saponin instead of a water-soluble protein can provide long-term foam stability, improved usability such as less dripping and easier mixing, and improved skin condition such as moisturized feel and elasticity, which are equivalent to or better than those of water-soluble proteins. For example, a skin topical agent containing a water-soluble protein may be difficult to use for users with allergies, but an extract containing saponin can be effectively used as a substitute for this water-soluble protein. Furthermore, the addition of an extract containing saponin has the effect of increasing the amount of carbon dioxide gas generated, and can contribute to effectively promoting blood circulation in the skin. The present inventors have found that the addition of an extract containing saponin, particularly the effects of improving usability and improving skin condition, is excellent when a polysaccharide or a derivative thereof, particularly two or more polysaccharides or derivatives thereof, are contained.

[0060] The extract containing saponin used in the skin external preparation of the present invention is preferably derived from plants.The examples of plants mentioned here include soybean, loofah, adzuki bean, kidney bean, spinach, sugar beet, grape, bellflower, licorice, Senega, Quillaja japonica, soapberry, ginseng, tea seed, and sophora japonica as the plants containing triterpenoid saponin, and lily family plants, Dioscorea japonica plants, Anemone arbutus, and Ophiopogon as the plants containing steroid saponin. The agent of the present invention preferably uses, as the saponin-containing extract, one or more of the above-mentioned various plants containing triterpenoid saponins, and preferably contains an extract of one or more plants selected from soapberry, soybean, licorice, and loofah, and more preferably contains an extract of soapberry. Here, soapberry is a plant belonging to the genus Sapindus in the family Sapindaceae, and corresponds to S. mukurossi, S. delavayi, etc.

[0061] Examples of plant parts that can be used as the raw material for the extract include the whole plant, leaves (leaf blades, petioles, etc.), fruits (mature, unripe, etc.), seeds, flowers (petals, ovaries, etc.), stems, rhizomes, roots, tuberous roots, etc. In the present invention, when an extract of Soapberry is used as an extract containing saponin, it is preferably an extract of the fruit and / or pericarp of Soapberry, and particularly preferably an extract of the pericarp.

[0062] The extract may be used from the whole plant or the above-mentioned parts, either as is, or after cutting, crushing, pulverizing, squeezing, or after drying or powdering the above-mentioned processed products. These processing methods may be used alone or in combination of two or more.

[0063] Examples of the solvent used for extraction include water; organic solvents such as methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, hexylene glycol, glycerin, methyl acetate, ethyl acetate, isopropyl acetate, ethyl ether, and acetone. These can be used alone or in combination of two or more. From the viewpoint of safety, it is preferable to use water, ethanol, or a mixture of these, which are harmless to the human body, as the extraction solvent. The extraction may be performed at a temperature below the boiling point of the extraction solvent, and the extraction time can be appropriately changed depending on the extraction temperature. The extract may contain water as the extraction solvent, but when the skin topical preparation of the present invention is a one-dose type skin topical preparation, it will not substantially contain water unless it contains the amount of water necessary for the acidic substance and the carbon dioxide gas generating substance to react during storage and generate carbon dioxide gas, so an extraction solvent containing water can also be used.

[0064] The extract is filtered to remove impurities, and then the extract is added to the skin topical preparation of the present invention in a solid form such as powder. For example, the extract obtained by extraction with the above-mentioned solvent may be freeze-dried or spray-dried to form a powder. Before the extract is solidified, it may be further purified within a range that does not impair the physiological activity of saponin.

[0065] From the viewpoint of further enhancing the above-mentioned effects, when the skin topical preparation of the present invention contains an extract containing saponin, the content of the extract in the skin topical preparation is preferably 0.001% by mass to 10% by mass, more preferably 0.005% by mass to 8% by mass. The content of the extract of 0.001% by mass to 10% by mass is preferable from the viewpoint of achieving both long-term foam stability and skin condition improving effect.

[0066] In addition, examples of glycyrrhizinic acid and its salts as natural surfactants in the present invention include dipotassium glycyrrhizinate (GK2). As described later, glycyrrhizinic acid and its salts also function as anti-inflammatory agents and whitening agents. In the present invention, when glycyrrhizinic acid and its salts are used as natural surfactants (or anti-inflammatory agents, whitening agents), as is clear from a comparison between Examples 4 and 5 described later, carbon dioxide gas is easily retained in the mixture of the skin external preparation and the water-containing substance for a long period of time, and the amount of carbon dioxide gas generated can be increased. In addition, the moisture content of the stratum corneum of the skin is increased, and the effect of improving the skin condition, such as enhancing redness, is enhanced, and the feeling of use of the skin external preparation can be improved. The preferred content of glycyrrhizinic acid and its salts in the skin external preparation of the present invention is the same as the preferred content of the anti-inflammatory agent described later.

[0067] Furthermore, the skin external preparation of the present invention preferably contains at least one selected from a bactericide, an anti-inflammatory agent, and a skin whitening agent.

[0068] Bactericides are substances that have bactericidal, bacteriostatic or antibacterial effects and do not cause problems for the skin when incorporated into skin topicals, and examples of such substances include salicylic acid and its salts or salicylic acid derivatives; antibiotics such as erythromycin, clindamycin, gentamicin, penicillin, chloramphenicol, and tetracycline; benzoyl peroxide; nadifloxacin; ethanol; benzalkonium chloride; sulfur; parahydroxybenzoate esters; hinokitiol; triclosan; homosulfamine; chloramine T; catechin and its derivatives; and chitin and chitosan derivatives. Furthermore, extracts having antibacterial effects may be used as antibacterial agents, and examples of such extracts include extracts of fennel, Phellodendron bark, tea, rose hips, chamomile, orange, yarrow, turmeric, gardenia, cloves, sage, saxifrage, clove, eucalyptus, cypress, and cedar. These may be used alone or in combination of two or more.

[0069] Among these bactericides, it is particularly preferable to use salicylic acid and its salts or salicylic acid derivatives, and it is particularly preferable to use salicylic acid. As will be apparent from the examples described later, the use of a bactericide such as salicylic acid in the skin external preparation of the present invention can improve the moisture content and elasticity of the stratum corneum of the skin after use. In order to further enhance this effect, when the topical skin preparation of the present invention contains a bactericide, the content thereof in the topical skin preparation is preferably 0.001% by mass or more and 20% by mass or less, and more preferably 0.005% by mass or more and 10% by mass or less.

[0070] Anti-inflammatory agents are substances that have the effect of suppressing inflammation, and examples thereof include glycyrrhizic acid and its salts, and derivatives thereof, which are mentioned above as natural surfactants.Other examples of anti-inflammatory agents include glycyrrhizic acid and its salts, mefenamic acid and its salts, phenylbutazone, indomethacin, ibuprofen acid and its salts, ketoprofen, allantoin, guaiazulene and its derivatives, ε-aminocaproic acid, zinc oxide, diclofenac sodium, proanthocyanidin, etc.Furthermore, extracts having anti-inflammatory effects can be used as anti-inflammatory agents, and examples of such extracts include saxifrage extract, licorice extract, aloe extract, lithospermum root extract, salvia extract, arnica extract, chamomile extract, white birch extract, hypericum extract, eucalyptus extract, peach leaf extract, pine bark extract, grape seed extract, and cowberry extract, and other animal and plant extracts.These can be used alone or in combination of two or more.

[0071] Among these anti-inflammatory agents, it is particularly preferred to use glycyrrhizinic acid and its salts, glycyrrhetic acid and its salts, and their derivatives, and it is particularly preferred to use glycyrrhizinic acid and its salts for the reasons mentioned above, and it is particularly preferred to use dipotassium glycyrrhizinate (GK2).When an anti-inflammatory agent is used in the skin external preparation of the present invention, it is possible to obtain the effect of suppressing skin inflammation and preventing acne and rough skin. From the viewpoint of further enhancing such effects, when the topical skin preparation of the present invention contains an anti-inflammatory agent, the content thereof in the topical skin preparation is preferably 0.001% by mass or more and 20% by mass or less, and more preferably 0.005% by mass or more and 10% by mass or less. When GK2 is used in the skin topical preparation of the present invention, not only is a high skin whitening effect obtained, but also a high skin condition improvement effect such as improvement of the stratum corneum moisture content and elasticity can be obtained, as will be clear from Example 7 described later. Furthermore, as will be clear from the descriptions of 16 and 7 described later, the skin topical preparation using GK2 is also excellent in terms of usability, such as ease of mixing and resistance to dripping.

[0072] The whitening agent mainly uses those having tyrosinase activity or those having melanin pigment decolorizing activity. Examples of such agents include L-cysteine ​​and its derivatives, ascorbic acid and its derivatives, tranexamic acid derivatives, glabridin, liquiritin, isoliquiritin, hydroquinone, arbutin, kojic acid, placenta, etc. In addition, the above-mentioned glycyrrhizic acid or salt, glycyrrhetinic acid and its salt and their derivatives can also be used as whitening agents. Furthermore, extracts having whitening action can also be used as whitening agents, and such extracts include mulberry bark extract, angelica extract, ivy trannula extract, keiketto extract, sophora arvensis extract, hawthorn extract, white lily extract, hop extract, multiflora rose extract, etc. These can be used alone or in combination of two or more kinds.

[0073] Of these skin whitening agents, it is preferable to use one or more selected from arbutin, placenta, glycyrrhizic acid or a salt thereof, ascorbic acid and a derivative thereof.

[0074] Arbutin used in the present invention is a compound also known by the systematic name 4-(β-D-glucopyranosyloxy)phenol. When arbutin is used in the skin topical preparation of the present invention, not only is a high effect of improving the whiteness of the skin obtained, but also a high effect of improving the skin condition such as moist feeling and elasticity, as will be apparent from Example 10 described later. Furthermore, as will be apparent from the descriptions of Examples 10 and 16 described later, the skin topical preparation using arbutin is also excellent in terms of usability such as ease of application, pleasant feeling when applied, spreadability, and ease of removal.

[0075] Placenta is a general term for the growth factors and other nutrients that promote cell division extracted from animal, particularly preferably pig, horse, cow, sheep, and human placenta, nutrients extracted from fish ovarian membrane, and nutrients extracted from plant germ.As is clear from the description of Example 15 below, the skin external preparation of the present invention containing placenta has the effect of reducing the amount of water evaporation after application and increasing smoothness and silkiness.In the present invention, any placenta can be used, but animal-derived placenta and fish-derived placenta can be used preferably.

[0076] From the viewpoint of further enhancing the above-mentioned effects, when the topical skin preparation of the present invention contains a whitening agent, the content thereof in the topical skin preparation is preferably 0.001% by mass or more and 30% by mass or less, and more preferably 0.005% by mass or more and 20% by mass or less.

[0077] In the skin external preparation of the present invention, other active ingredients can be used instead of or in addition to the above-mentioned saponin-containing extract, bactericide, anti-inflammatory agent, and whitening agent. Examples of such active ingredients include gold leaf, pearl powder, mud, charcoal, gypsum, enzymes, herbs, seaweed, fermented products such as yogurt, whey, sake, and koji, moisturizing ingredients such as honey, propylene glycol, polyethylene glycol, sorbitol, sodium lactate, and sodium pyrrolypyrrolidone carboxylate, plant ingredients such as licorice, and vitamins. Among them, gold leaf and pearl powder are particularly preferred. As is clear from the description of Example 11 described below, the use of gold leaf improves the feeling of use, such as pleasantness when applied and good appearance, and also provides an effect of improving skin condition. As is clear from the description of Example 12 described below, the use of pearl powder also provides an effect of improving skin condition, such as skin brightness, and also provides an improvement in feeling of use.

[0078] Pearl powder is a powder obtained by pulverizing cultured or natural pearls, which are spherical or amorphous metabolic products formed in marine shells such as Akoya pearl oysters, Black Lip Oysters, White Lip Oysters, Mabe pearl oysters, and Abalone pearl oysters, and freshwater shells such as Ikebana pearl oysters, by a known method such as a ball mill, a jet mill, or a turbo mill, and then sieving the resulting powder. When pearl powder is contained, the content of the powder in the skin topical preparation is preferably 0.0001% to 10% by mass. When gold leaf is contained, the content of the powder in the skin topical preparation is preferably 0.0001% to 10% by mass.

[0079] The foamable topical skin preparation of the present invention may further contain one or more ingredients that are normally used in topical skin preparations, such as thickeners other than polysaccharides and their derivatives, and water-soluble proteins; excipients, granulating agents; pH adjusters; oils and fats; fragrances; colorants; antioxidants; antibacterial and antifungal agents; alcohols, polyhydric alcohols; inorganic salts; lubricants; solvents; and extracts of animals and plants.

[0080] Examples of thickeners other than polysaccharides and their derivatives and water-soluble proteins include organic hydrophilic synthetic polymers such as polyvinyl alcohol, acrylates / alkyl acrylate crosspolymer, polyacrylic acid, polyacrylamide, polyalkylacrylamide / polyacrylamide copolymer, poloxamer (Pluronic (registered trademark)), polyvinylpyrrolidone, and acrylic acid / alkyl methacrylate copolymer, and inorganic hydrophilic thickening compounds such as hydrophilic clay minerals such as laponite, bentonite, and smectite, and silica and talc. The acrylic acid / alkyl methacrylate copolymer is a compounding component that functions as a polymer emulsifier, and for example, an (acrylates / alkyl acrylate (C10-30)) crosspolymer can be used.

[0081] As the excipient or granulating agent, for example, powders such as lactose, powdered sugar, xylitol, D-sorbitol, glucose, D-mannitol, fructose, sucrose, sucrose, urea, etc. can be used alone or in combination of two or more kinds without particular limitation. When such an excipient and / or granulating agent is contained, the content thereof in the external preparation for skin of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more and 88% by mass or less.

[0082] In the topical skin preparation of the present invention, the total content of other ingredients other than the acidic substance, the carbon dioxide gas generating substance, the polysaccharide or its derivative, the water-soluble protein, the natural surfactant, the bactericide, the anti-inflammatory agent, the whitening agent, the excipient or granulating agent is preferably 40% by mass or less, and more preferably 30% by mass or less.

[0083] When the topical skin preparation of the present invention contains, in addition to (4) polysaccharides or derivatives thereof, at least one thickener selected from the inorganic hydrophilic thickening compounds and the hydrophilic synthetic polymers, which are organic thickeners, as a thickener other than the above-mentioned polysaccharides and their derivatives and water-soluble proteins, as well as the above-mentioned polysaccharides and their derivatives (1) to (3), the effect of "good sensation when used and improvement of skin condition" is remarkable, as in the case of the above-mentioned polysaccharides and their derivatives (1) to (3) in which two or more of the above-mentioned polysaccharides and their derivatives are combined. The effect of the present invention is obtained by the agent of the present invention containing a polysaccharide or a derivative thereof, and the above-mentioned hydrophilic thickening compound or the above-mentioned hydrophilic synthetic polymer together with a solid acidic substance and a solid carbon dioxide gas generating substance. Therefore, the effect of the present invention cannot be obtained by, for example, a viscous composition containing either or both of the combination of the above-mentioned (4) polysaccharide or a derivative thereof and the above-mentioned hydrophilic thickening compound or the above-mentioned hydrophilic synthetic polymer together with water, and mixing this viscous composition with a solid acidic substance and / or a solid carbon dioxide gas generating substance when used.

[0084] In the present invention, when the topical skin preparation contains (4) an inorganic hydrophilic thickening compound or a hydrophilic synthetic polymer that is an organic thickening agent, preferred examples of the polysaccharide or its derivative contained in the topical skin preparation include hydrophilic natural polymers, cellulose derivatives, and starch derivatives. Examples of the hydrophilic natural polymers include alginic acid and its salts, carrageenan, locust bean gum, tamarind gum, and guar gum.

[0085] In particular, the polysaccharide or derivative thereof in (4) is preferably at least one selected from alginic acid and its salts, carrageenan, locust bean gum, tamarind gum, guar gum, ethyl cellulose, carboxymethyl cellulose and its derivatives, and salts thereof, hydroxyethyl cellulose and its derivatives, hydroxypropyl methyl cellulose and its derivatives, sulfonated cellulose derivatives, carboxymethyl ethyl cellulose and its salts, cellulose acetate phthalate, cationic cellulose, and croscarmellose and its salts, and is particularly preferably at least one selected from alginic acid and its salts, carrageenan, carboxymethyl cellulose and its derivatives, and salts thereof, guar gum, hydroxyethyl cellulose and its derivatives, and cationic cellulose.

[0086] In the present invention, when (4) the above-mentioned inorganic hydrophilic thickening compound or hydrophilic synthetic polymer that is an organic thickening agent is contained, it is also preferable to use xanthan gum as the polysaccharide or its derivative. In this case, it is particularly preferable to combine xanthan gum with talc.

[0087] In the case of (4), when the skin external preparation of the present invention contains a specific hydrophilic natural polymer, cellulose derivative or starch derivative as a polysaccharide or its derivative, the amount of inorganic hydrophilic thickening compound or hydrophilic synthetic polymer as organic thickener is preferably 1 part by mass or more and 10000 parts by mass or less, more preferably 5 parts by mass or more and 5000 parts by mass or more, and particularly preferably 10 parts by mass or more and 1000 parts by mass or less, relative to 100 parts by mass of the hydrophilic natural polymer, cellulose derivative or starch derivative.Here, the amount of the specific hydrophilic natural polymer, cellulose derivative or starch derivative is the total amount if it contains two or more of these.In addition, the amount of the hydrophilic thickening compound or hydrophilic synthetic polymer is the total amount if it contains two or more of these. Furthermore, when specific types of hydrophilic natural polymers, cellulose derivatives, starch derivatives, hydrophilic thickening compounds, and hydrophilic synthetic polymers are contained, the amounts of the above-mentioned hydrophilic natural polymers, cellulose derivatives, starch derivatives, hydrophilic thickening compounds, and hydrophilic synthetic polymers can be the amounts of the specific types of hydrophilic natural polymers, cellulose derivatives, starch derivatives, hydrophilic thickening compounds, and hydrophilic synthetic polymers (the same applies below).

[0088] In the topical skin preparation of the present invention, the total content of the specific hydrophilic natural polymer, cellulose derivative, starch derivative, hydrophilic thickening compound and hydrophilic synthetic polymer is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and particularly preferably 12% by mass or more and 45% by mass or less.

[0089] The dosage form of the external skin preparation of the present invention is usually solid, and examples of such forms include powder, granules, fine granules, pellets, or a combination of two or more of these. From the viewpoints of reducing the cost during production and ease of dissolution during use, the powder form is preferred.

[0090] For example, when the skin topical preparation of the present invention is in granular form, the entire preparation may be in granular form, or only a portion of the preparation may be in granular form. When only a portion of the preparation is in granular form, the acidic substance and / or the carbon dioxide gas generating substance may be in granular form. In this case, the granules may contain other components (one or more of the various components described above, such as excipients, granulating agents, polysaccharides or derivatives thereof, water-soluble proteins, etc.). In addition, components other than the acidic substance and the carbon dioxide gas generating substance may be in granular form.

[0091] For example, when granules of the solid acidic substance and / or the solid carbon dioxide gas generating substance are obtained by granulating a mixture of the acidic substance and / or the carbon dioxide gas generating substance with other components, the content of the other components is not particularly limited, but is preferably less than 80 mass% in the granules. If the other components are present in an amount exceeding 80 mass%, the foaming property is reduced, which is not preferable.

[0092] The method for producing the granules is not limited to that in this embodiment, and the granules 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.

[0093] For example, when a low melting point compound is used in the granulating agent as a matrix base, the acidic substance and / or the carbon dioxide gas generating substance and other components as required are added to the low melting point granulating agent 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 further stirring and left to stand until it solidifies. Once it has solidified to a certain extent, it may be rapidly cooled in a refrigerator or the like.

[0094] Alternatively, for example, the above materials may be charged into a fluidized bed granulator, mixed with an air current for several minutes, and then granulated by spraying water thereon.

[0095] When a low melting point 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 acidic substance and / or the carbon dioxide gas generating substance and other components as necessary are dissolved or dispersed in this, mixed thoroughly, heated in an oven or the like to remove the solvent, and then dried. Once completely solidified, the mixture is pulverized and sieved to adjust the particle size, and then granulated.

[0096] The shape of the solidified acidic substance or solid carbon dioxide gas generating substance as described above can be, for example, irregular, planar, polyhedral, spherical, teardrop, fibrous, cylindrical, fine powder, etc., without any particular limitation. In addition, a wide range of particle sizes can be used without any particular limitation. In particular, from the viewpoints of ease of handling and ease of mixing with a water-containing substance, a particle size distribution of about 1,000 μm is more preferable. The particle size distribution in the present invention can be determined by a conventional laser diffraction / scattering method.

[0097] In the present invention, it is preferable that the acidic substance and the carbon dioxide gas generating substance are contained in the same agent, and are blended so that the acidic substance and the carbon dioxide gas generating substance do not come into physical contact with each other in the same agent, and coexist. The means for making them coexist is not particularly limited and can be widely applied.

[0098] When the acidic substance and the carbon dioxide gas generating substance are blended so as not to come into physical contact with each other, for example, a coating layer may be provided on either or both of the acidic substance and the carbon dioxide gas generating substance, or either or both of the acidic substance and the carbon dioxide gas generating substance may be encapsulated. Also, a layer not containing the acidic substance and the carbon dioxide gas generating substance may be sandwiched between the acidic substance and the carbon dioxide gas generating substance so as not to come into direct contact with each other, and compression molding may be performed.

[0099] Means for making the acidic substance and the carbon dioxide gas generating substance coexist in the same agent will be specifically described below, but the present invention is not limited thereto.

[0100] [Coat layer formation] As a method for forming a coating layer, for example, a method of forming a coating layer on at least one of an acidic substance and a carbon dioxide gas generating substance may be used. By providing a coating layer, even if the acidic substance, the carbon dioxide gas generating substance, and other components are coexisted in the same agent, there is no risk of unexpected carbon dioxide gas generation during production or storage, which is preferable from the viewpoints of stability and durability.

[0101] The coating agent suitable for forming the coating layer is not particularly limited as long as it has low reactivity with the acidic substance or the carbon dioxide gas generating substance. For example, oils and fats, fatty acids, fatty acid salts, acetyl cellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol, sodium polyacrylate, hydroxypropyl methyl cellulose, methyl methacrylate-methacrylic acid copolymer, ethyl acrylate-methacrylic acid copolymer, gum arabic, sodium alginate, soluble starch, hydroxypropyl cellulose, wheat starch, white sugar, lactose, citrate, etc. are listed. In particular, when coating an acidic substance such as citric acid, it is preferable to adopt a citrate such as calcium citrate. In addition, a coating layer may be formed using a solid hydrocarbon wax, solid oil, etc. that melts at a certain temperature or higher when heated.

[0102] The amount of the coating agent used for the acidic substance and / or carbon dioxide gas generating substance is preferably about 1 to 20% (w / w), more preferably about 1 to 10% (w / w), based on the acidic substance or carbon dioxide gas generating substance.

[0103] The coating method of the coating layer may be any method that is usually used for coating particles. For example, the coating may be performed simultaneously with granulation by spray granulation or rolling granulation, or the powder or granulated material may be coated by a method such as oil coating, granulation coating, transport layer method, pan coating, rolling coating, fluidized coating, or dry coating. If excessive heat or physical force is applied during coating, the acidic substance or the carbon dioxide gas generating substance is destroyed and the generated coating is broken, making it difficult to uniformly coat the lipid powder over the entire surface of the acidic substance or the carbon dioxide gas generating substance, and the acidic substance or the carbon dioxide gas generating substance may leak onto the surface, causing solidification due to moisture absorption, or causing adverse effects on other components during blending. Therefore, the coating conditions must be such that the coating layer and the coating target are not destroyed.

[0104] [Encapsulation] When the acidic substance and / or the carbon dioxide gas generating substance are encapsulated, any known method may be used without any particular limitation.

[0105] The encapsulation method may be any known method without any particular limitation, and the encapsulation materials may include gelatin, starch, gum arabic, methyl cellulose, acrylic acid esters, methacrylic acid esters, vinyl acetate, polyvinyl alcohol, silicone resins, solid wax, polyethylene, fatty acids, higher alcohols, and the like, as well as multi-layered surfactants such as liposomes, and may be widely used without any particular limitation. For example, it is also preferable to use a resin capsule whose basic structure is made of a homopolymer or copolymer formed from one or more monomers selected from acrylic acid esters, methacrylic acid esters, vinyl acetate, and styrene, or a copolymer formed from the above monomer and a monomer selected from acrylic acid, methacrylic acid, divinylbenzene, and ethylene glycol dimethacrylate. Such microcapsules may be prepared by emulsifying the contents and the constituent monomers of the polymer that constitutes the capsule shell in a reaction solvent such as water, adding a polymerization initiator such as azobisisobutyronitrile or benzoyl peroxide to the emulsion polymerization. A suitable example of a surface active ingredient used in such emulsification is Hexlite, which is sold under the name "Laponite XLG." The resulting microcapsules are separated by a means such as centrifugation, and if desired, washed to produce the microcapsules of the present invention.

[0106] [Compression molding] As a method of compression molding, a method of sandwiching a third layer consisting of a substance other than the acidic substance and the carbon dioxide gas generating substance (e.g., an excipient, a thickener, etc.) between the first layer containing the acidic substance and the second layer containing the carbon dioxide gas generating substance so that they are not in direct contact with each other, and compression molding may be adopted. The compression molded dosage form may be any dosage form as long as it is solid, such as a tablet, a sphere, a plate, etc. Here, the acidic substance and the carbon dioxide gas generating substance used may be used as they are, or the acidic substance or the carbon dioxide gas generating substance may be provided with a coating layer by the above method on at least one of the first layer or the second layer, or the acidic substance or the carbon dioxide gas generating substance may be encapsulated. The compression molding method is not particularly limited, and a known method may be applied.

[0107] The topical skin preparation of the present invention may be one other than the topical skin preparations described below. "A one-component external preparation for the skin which contains at least a solid acidic substance, a solid carbon dioxide gas generating substance which generates carbon dioxide gas upon reaction with the acidic substance, and a thickener, and which does not contain water, wherein the thickener is contained in an amount of 12 to 45 mass% of the total external preparation for the skin, the thickener is used in combination with albumin and other thickeners, and the external preparation for the skin is mixed with a liquid containing water when the external preparation for the skin is used." Examples of thickeners include hydrophilic synthetic polymers such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl methylcellulose, sulfonated cellulose derivatives, acrylates / alkyl acrylate crosspolymer, polyacrylic acid, polyacrylamide, polyalkylacrylamide / polyacrylamide copolymer, carboxymethyl cellulose, cationic cellulose, and Pluronic; hydrophilic natural polymers such as starch, xanthan gum, sodium alginate, succinoglycan, carrageenan, guar gum, locust bean gum, and celluloses; and hydrophilic thickening compounds such as hydrophilic protein compounds such as chondroitin sulfate, casein, collagen, gelatin, and albumin; and hydrophilic clay minerals such as laponite, bentonite, and smectite.

[0108] <Usage forms of topical skin preparations> When used, the skin external preparation of the present invention is mixed with a water-containing substance on the palm of the hand or in a container to generate foam. The skin external preparation of the present invention may be used as a one-dose type skin external preparation, or may be used as a two-dose type that constitutes a kit with a water-containing substance. When the skin external preparation of the present invention is a one-dose type, as described above, the skin external preparation is usually a solid composition, and more preferably in the form of a solid, granular, fine granule, or powder, and is particularly preferably in the form of a granular, fine granule, or powder because it is easy to mix with a water-containing substance and is easy to foam. In addition, when the skin external preparation of the present invention is a one-dose type, it usually does not substantially contain water. Here, "not substantially containing water" means that the acidic substance and the carbon dioxide gas generating substance react during storage of the skin external preparation and do not contain the amount of water necessary for carbon dioxide gas generation. Specifically, the amount of water contained in the skin external preparation of the present invention is 15% by mass or less, preferably 10% by mass or less, more preferably 8% by mass or less. When the skin external preparation of the present invention is a two-dose type that constitutes a kit with a water-containing substance, the agent containing an acidic substance, a carbon dioxide gas generating substance, and at least one type of polysaccharide is usually a solid composition, more preferably in the form of a solid, granular, fine granule, or powder, and particularly preferably in the form of a granular, fine granule, or powder, because it is easy to mix with the water-containing substance and foams easily. In addition, when the skin external preparation of the present invention is a two-dose type, the solid composition usually does not substantially contain water. Here, "substantially does not contain water" means that the acidic substance and the carbon dioxide gas generating substance react during storage of the skin external preparation and do not contain the amount of water necessary to generate carbon dioxide gas. Specifically, the amount of water contained in the skin external preparation of the present invention is 15% by mass or less, preferably 10% by mass or less, more preferably 8% by mass or less. When the skin external preparation of the present invention is a one-dose type, the user usually prepares a water-containing substance to be mixed with the skin external preparation, and when it is a two-dose type, as described above, the skin external preparation of the present invention and the water-containing substance constitute a kit. When the skin external preparation is a one-component type, the water-containing liquid is often used as the water-containing substance.When the skin external preparation is a two-component type, the water-containing liquid or gel can be mentioned as an example.The water-containing substance is preferably a liquid, more preferably a liquid with low viscosity, and particularly preferably a liquid without viscosity.The water-containing substance is preferably substantially free of the thickener.Specifically, the content of the thickener in the water-containing substance is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, and particularly preferably 0.01% by mass or less. In particular, when the skin topical preparation is a two-component type, it is preferable to mix the skin topical preparation with a liquid, particularly a liquid with a relatively low viscosity, since the effect of the present invention is more effectively achieved than when it is mixed with a gel. When the skin topical preparation of the present invention is mixed with a gel or a liquid with a relatively high viscosity, it is not preferable because it is difficult to mix the two agents and it takes a long time to foam. Specifically, the viscosity of the water-containing substance at 25°C is preferably 50000 mPa·s or less, more preferably 30000 mPa·s or less, particularly preferably 10000 mPa·s or less, and even more preferably 5000 mPa·s or less. This viscosity can be measured with the viscometer used in the following examples. In addition, the water content in the water-containing substance may be 10% by mass or more, and preferably 30% by mass or more. The water content is more preferably 40% by mass or more, even more preferably 50% by mass or more, particularly preferably 70% by mass or more, and even more preferably 80% by mass or more. If the water content is less than 10% by mass, carbon dioxide gas is hardly generated when the external preparation for skin is mixed with the water-containing substance, and the effect of promoting blood flow during use cannot be obtained. Here, a high lower limit of 70 mass % or more or 80 mass % or more can be adopted in either one- or two-component types, but is particularly preferable in the case of a one-component type.

[0109] When the skin external preparation of the present invention is a one-dose type, it is characterized by being low-cost and easy for users to handle compared to two-dose types because it is made into a one-dose type. In the case of a one-dose type, the water-containing substance used in the present invention can be a water-containing liquid that is usually used in cosmetics, medicines, etc., or used in general households. The water-containing liquid may be water itself. Specifically, in addition to tap water, distilled water, membrane-filtered water, ion-exchanged water, and deep sea water, alcoholic beverages such as sake and wine, soy milk, drinking yogurt, acerola juice, sports drinks, beverages such as carbonated water, rice water, etc. can be mentioned. These can be used alone or in a mixture of two or more types.

[0110] In addition, when the skin external preparation of the present invention is combined with a water-containing substance to form a two-dose type, the water-containing substance can be, as described above, a liquid or gel containing water, and can be any of the above-mentioned water and water-containing liquids to which any optional ingredient has been added.As this ingredient, it is possible to add known ingredients contained in the liquids of two-dose skin external preparations, such as moisturizers, surfactants, pH adjusters, volatile alcohols, oils and fats, fragrances, animal and plant extracts, etc. For example, moisturizing agents include polyglycerins such as glycerin, diglycerin, triglycerin, and tetraglycerin, polyhydric alcohols such as ethylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, 1,3-propanediol, sorbitol, and polyglycerin derivatives, polyoxyalkylene alkyl glucoside, sodium lactate, sodium pyrrolidone carboxylate, almond, avocado, althea, aloe, mallow, ononis, oat, licorice, quince seed, sophora flavescens, and gardenia. , grapefruit, watercress, gentian, geranium herb, burdock, wheat, saishin, cactus, soapwort, hawthorn, rehmannia, meadowsweet, ginger, mallow, mulberry, thyme, cordyceps, houttuynia, peppermint, Job's tears, witch hazel, rose, cypress, coltsfoot, grape, prune, loofah, linden, hops, pine, quince, horse chestnut, melissa, cornflower, lily, lime, lavender, apple, rice and rice bran, blackcurrant, Ibuki toranoo, Rosa multiflora, Eleuthero, seaweed, and other plant extracts can be used alone or in combination.

[0111] The amount of the 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 skin topical preparation, and more preferably 2 to 5 times the mass. By adding more than 1 times the amount of liquid, the skin topical preparation can be quickly dissolved and a sufficient amount of carbon dioxide gas can be generated. On the other hand, by adding the liquid within 10 times the amount, dripping due to a decrease in the viscosity of the skin topical preparation can be prevented.

[0112] The temperature of the water-containing substance to be used is not particularly limited and can be in a wide range, but it is particularly preferable to cool it before use, as this enhances the activity of the active ingredients contained in the skin topical agent. From the viewpoint of the feeling of use during application and convenience for the user, it is preferable to use water at about room temperature or tap water.

[0113] There is no particular limitation on the method of preserving the skin external preparation, so long as it is preserved in a state that is protected from moisture and does not come into contact with the skin.The shape of the preservation container used can be appropriately selected according to the purpose, and includes cup-shaped, tube-shaped, bag-shaped, bottle-shaped, stick-shaped, pump-shaped, jar-shaped, canned, etc.In addition, the material constituting the preservation container can be, for example, plastic, glass, aluminum, paper, various polymers, etc., alone or in combination of two or more kinds, but is not limited thereto.

[0114] Specific examples of containers that are preferable in terms of airtightness, storage stability of the contents, production costs, etc. include storage containers such as aluminum sticks and aluminum bags whose inner surface is laminated with polyethylene terephthalate, stand pouches with zippers, and storage containers made of polyethylene terephthalate whose lids are heat-sealed with aluminum films whose inner surface is laminated with polyethylene terephthalate, etc.

[0115] According to the skin external preparation of the present invention, as will be clear from the description of the examples below, it has a good feeling of use and has an excellent effect of improving skin condition. Examples of the feeling of use include the ease of mixing the mixture of the skin external preparation and the water-containing substance into the skin, the ease of application, the difficulty of dripping, the ease of removal, the smoothness of the foam, the fineness of the foam, the uniformity of the foam (no roughness of powder), the elasticity of the foam, the foam retention, the carbonation (stimulating feeling), the persistence of the carbonation feeling, etc. In addition, the effect of improving the skin condition includes the improvement of moist feeling, elasticity, brightness, redness, smoothness, tightening feeling, whiteness, the increase of the keratin moisture content, the suppression of the amount of moisture evaporation, etc. As will be clear from the description of Example 24 below, according to the skin external preparation of the present invention, it may be possible to obtain the effect of making wrinkles less noticeable.

[0116] <Uses of topical skin preparations> The skin topical preparation of the present invention promotes an increase in the blood flow in the skin, and by utilizing the above-mentioned effects, it is possible to achieve a number of effects, including whitening, improving skin quality, improving freckles, rejuvenating the skin, tightening the skin, thinning the skin in specific areas, cleansing the skin, conditioning the skin, improving 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 flexibility of the skin, protecting the skin, preventing the skin from drying out, softening the skin, giving the skin elasticity, giving the skin a glossy look, smoothing the skin, and reducing sun spots and blemishes. It can be suitably used not only in cosmetics intended to prevent skin rashes and to make fine wrinkles caused by dryness less noticeable, but also in quasi-drugs and pharmaceuticals such as medicines intended to prevent rough skin, chapped skin, heat rash, chilblains, cracks, chapped skin, acne, oily skin, razor burn, sunburn spots and freckles, prevent hot flashes after sunburn and snowburn, tighten skin, cleanse skin, condition skin, keep skin healthy, moisturize skin, protect skin, prevent dry skin, etc. The skin topical agent of the present invention is preferably used as a cosmetic or quasi-drug, and is preferably used as cosmetics or medicinal cosmetics such as emulsions, creams, packs, and peeling agents. In particular, it is preferable to use it as a pack agent, since it is easy to obtain a good feeling of use and a high effect of improving skin condition. EXAMPLES

[0117] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. In the following examples and comparative examples, the raw materials used were commercially available products unless otherwise specified.

[0118] <Examples 1 to 10 and Comparative Examples 1 to 3> The components shown in Table 1 were blended and mixed in the compositions shown in the same table to produce powdered topical skin preparations of Examples 1 to 10 and Comparative Examples 1 to 3. The values ​​in Table 1 below are the mass percentages (mass%) in the topical skin preparations.

[0119] [Table 1]

[0120] The properties of the external skin preparations of the above Examples and Comparative Examples were evaluated according to the procedures described below in [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3].

[0121] [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3] (1) Sensory evaluation Three healthy women in their 20s and 30s were randomly selected as subjects. The subjects washed the inside of their forearms with a facial cleanser and rested in a measurement room for 15 minutes. Next, a powdered skin topical agent sample and water were mixed in a container at a ratio of 1:3 (by mass) to obtain a mixture that was a foam-like pack cosmetic. This mixture was applied to a 4 cm x 4 cm area on the inside of the forearm. Ten minutes after application, the mixture was removed from the forearm and the forearm was washed with water. After that, a questionnaire was conducted on the four items of "ease of mixing," "ease of application," "resistance to dripping," and "ease of removal" as evaluations of the feeling of use, and on the four items of "moisturizing," "skin elasticity," "skin brightness," and "skin redness" as evaluations of the skin condition after use. Each item was scored on a seven-point scale as shown in Table 2, and the scores were tallied and the average of the three subjects was calculated. The results are shown in Table 3. Regarding "resistance to dripping," the more the mixture was resistant to dripping from the skin after application, the higher the evaluation was. In addition, for "moisture content," the higher the moisture content of the skin, the higher the score was given, and for "skin redness," the stronger the redness of the skin, the higher the score was given.

[0122] [Table 2]

[0123] [Table 3]

[0124] From the results of Table 3 above, it can be seen that the skin external preparations of each Example containing polysaccharides or their derivatives are superior to those of Comparative Examples 1 to 3 in terms of both the feeling of use, such as ease of mixing, ease of application, resistance to dripping, and ease of removal, and the effect of improving skin conditions, such as moisturizing, elasticity, brightness, and redness. Furthermore, it can be seen that Examples 2, 6 to 10, which contain two or more types of polysaccharides or their derivatives, have a higher effect of improving both the feeling of use and the skin condition. In addition, when a water-soluble protein is contained as in Examples 3, 6, 8, and 10, the effect of improving the feeling of use and the skin condition is further improved, and when an extract containing saponin, a natural surfactant, is contained instead of a water-soluble protein as in Examples 4, 5, 7, and 9, these effects are equal to or higher than those of a water-soluble protein. It can also be seen that high effects are obtained in Examples 3, 5 to 10, which contain GK2, salicylic acid, or arbutin. For example, as is clear from a comparison between Examples 4 and 5, the inclusion of GK2, which is a natural surfactant (and also an anti-inflammatory agent and whitening agent), not only enhances the effect of improving skin conditions such as redness, but also improves the feel of the skin topical agent when used. From the above results, it can be seen that, compared to Example 1, in which one type of polysaccharide or its derivative was used, when two types of polysaccharide or its derivative were used as in Examples 2 to 5, or when a water-soluble protein or a natural surfactant was used in combination, a higher feel of use and a skin condition improving effect can be obtained. It can also be seen that the use of two or more types of polysaccharide or its derivative in combination with a water-soluble protein or a natural surfactant as in Examples 6 to 10 further improves both the feel of use and the skin condition improving effect.

[0125] (2) Skin condition measurement Regarding the sensory evaluation in (1) above, the L* value, keratin moisture content, and elasticity of the area on the inside of the forearm where the mixture was to be applied before application of the mixture were measured using the following measuring device. Then, after removing the mixture and washing with water, the L* value, keratin moisture content, and elasticity of the area on the inside of the forearm where the mixture was applied were similarly measured. From the measured values ​​obtained, the average value of the three subjects was calculated. The average value after use of the skin topical agent was divided by the average value before use, and the obtained value was taken as the rate of change. The rate of change of the L* value (whiteness) is shown in Figure 1, the rate of change of the keratin moisture content in Figure 2, and the rate of change of elasticity in Figure 3. In these figures, the higher the rate of change, the higher the evaluation.

[0126] ·L* value: Measured using a color difference meter (Konica Minolta CR-400). - Moisture content of stratum corneum: Measured using a skin surface stratum corneum moisture content measuring device SKICON-200EX (manufactured by IBS Co., Ltd.) This skin surface 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 elasticity measuring device, Cutometer MPA580 (manufactured by Courage+Khazaka). These measurements were performed according to standard procedures described in the instructions provided with the instrument.

[0127] From the results of Figures 1 to 3, it can be seen that the change rates of the L* value, keratin moisture content, and elasticity of the skin after use of the skin topical preparation are equal to or higher than those of the comparative examples in each Example. In particular, it can be seen that the change rates of the L* value, keratin moisture content, and elasticity are increased by one or more factors selected from the inclusion of two or more types of polysaccharides or their derivatives, the inclusion of a water-soluble protein, the inclusion of an extract containing saponin, which is a natural surfactant, the inclusion of glycyrrhizinate, which is a natural surfactant (inflammatory agent and whitening agent), and the inclusion of other whitening agents or bactericides. For example, a comparison between Examples 1 and 2 shows that the inclusion of two or more types of polysaccharides or their derivatives improves the L* value, keratin moisture content, and elasticity. A comparison between Examples 1 and 3 shows that the inclusion of a water-soluble protein and glycyrrhizinate improves the L* value, keratin moisture content, and elasticity. A comparison between Examples 1 and 4 shows that the inclusion of an extract containing saponin improves the L* value, keratin moisture content, and elasticity. A comparison of Examples 4 and 5 shows that the inclusion of glycyrrhizinate improves the moisture content of the stratum corneum. A comparison of Examples 6 and 8 and a comparison of Examples 7 and 9 shows that the inclusion of a disinfectant improves the moisture content and elasticity of the stratum corneum. Example 10 shows that the inclusion of arbutin as a whitening agent improves the L* value.

[0128] (3) Evaluation of topical skin preparations 27 mL of water was placed in a 225 mL bottle with a diameter of approximately 4.8 cm and a height of approximately 10.5 cm, and 9 g of a powdered skin preparation sample was added and stirred 20 times within 10 seconds. The resulting mixture was evaluated for the following <foaming amount> and <carbon dioxide gas generation amount>.

[0129] <Amount of foaming> The volume of the mixture was measured 1 minute, 10 minutes, and 20 minutes after stirring, and the volume increase rate (%) relative to the volume before stirring was calculated. The results are shown in Figure 4.

[0130] <Amount of carbon dioxide generated> Carbon dioxide gas generated from the mixture after stirring was collected by water displacement. The cumulative amount (mL) of collected carbon dioxide gas was measured at each time point: 3, 5, 7, 10, 15, 20, and 30 minutes after stirring. The results are shown in Figure 5.

[0131] From the results of FIG. 4, it can be seen that the volume of the mixture of the skin external preparations of each Example is not easily reduced even after time has passed after stirring, and a certain amount of carbon dioxide gas is retained in the mixture. This effect is enhanced by one or more factors selected from the inclusion of two or more types of polysaccharides or their derivatives, the inclusion of water-soluble proteins, the inclusion of an extract containing saponin, and the inclusion of glycyrrhizinate, and the inclusion of other whitening agents or bactericides, particularly the inclusion of an extract containing water-soluble proteins or saponin or the inclusion of glycyrrhizinate. For example, a comparison between Examples 1 and 2 shows that the inclusion of two or more types of polysaccharides or their derivatives improves the carbon dioxide gas retention in the resulting mixture. A comparison between Examples 1 and 3 shows that the inclusion of a water-soluble protein and a glycyrrhizinate improves the carbon dioxide gas retention in the resulting mixture. A comparison between Examples 1 and 4 shows that the inclusion of an extract containing saponin improves the carbon dioxide gas retention in the resulting mixture. A comparison between Examples 4 and 5 shows that the inclusion of a glycyrrhizinate improves the carbon dioxide gas retention in the resulting mixture. In contrast, in each of the comparative examples, the air bubbles in the mixture were difficult to retain and the volume of the mixture after stirring was likely to decrease, that is, the amount of carbon dioxide gas that could be retained in the mixture was small.

[0132] From the results of FIG. 5, it can be seen that in each Example, carbon dioxide gas is generated relatively slowly for a period of 5 minutes from stirring, and even after that, although the gradient is gentle in some cases, the generation of carbon dioxide gas from the mixture continues without stopping. In particular, it can be seen that in Examples 2 to 10, which contain two or more polysaccharides or derivatives thereof, extracts containing water-soluble proteins or saponins, glycyrrhizinates, or other whitening agents and bactericides, the generation of carbon dioxide gas tends to continue for a long time. For example, a comparison between Examples 1 and 3 shows that the amount of carbon dioxide gas generated is improved when a water-soluble protein and a glycyrrhizinate are contained. Also, a comparison between Examples 1 and 4 shows that the amount of carbon dioxide gas generated is improved when an extract containing saponins is contained. Also, a comparison between Examples 4 and 5 shows that the amount of carbon dioxide gas generated is improved when a glycyrrhizinate is contained. In contrast, in each of Comparative Examples 1 to 3, the rate of carbon dioxide gas generation was high up to 3 minutes after stirring, but thereafter the generation stopped or the amount of carbon dioxide gas generated itself was low.

[0133] <Examples 11 to 17> Powdered skin preparations were produced by blending and mixing the components in the blending ratios shown in Table 4 below. The values ​​in Table 4 are the mass percentages (mass%) in the skin preparations.

[0134] [Table 4]

[0135] [Evaluation of Examples 11 to 17] <Sensory evaluation> As subjects other than the subjects who evaluated Examples 1 to 10 and Comparative Examples 1 to 3, three healthy women in their 20s and 30s were randomly selected. After using the powdered skin topical preparation samples in the same manner as in "(1) Sensory Evaluation" in [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3] above, each subject was given a questionnaire for the following evaluation items. For each item, Example 17 was set as the standard (4.0 points), and scores were assigned on a 7-point scale shown in Table 2 above. After tallying up the scores, the average score for the three subjects was calculated. The results are shown in Table 5 below. In addition, the more tingling the following "irritation" was, the higher the evaluation was given. In addition, the less sticky the "stickiness of the skin" was, the higher the evaluation was given. Evaluation items: Eight items were assessed during use: "Ease of application," "Comfort when applying," "Appearance of the applied mixture," "Resistance to dripping," "Stimulation (presence or absence of tingling sensation)," "Easiness of spreading of the mixture," "Resistance of stickiness of the mixture," and "Ease of removing the mixture." Seven items were assessed after use: "Skin moistness," "Smoothness of skin," "Smoothness of skin," "Skin stickiness," "Skin firmness," "Skin tightening feeling," and "Skin brightness," for a total of 15 items.

[0136] [Table 5]

[0137] From the results of Table 5 above, it can be seen that in Examples 11 to 16, in which the composition of Example 17 containing an acidic substance, a carbon dioxide gas generating substance, a polysaccharide or its derivative, and one water-soluble protein is further supplemented with each active ingredient (including the second water-soluble protein), both the feeling of use and the effect of improving the skin condition are improved. In particular, it can be seen that the use of the skin topical preparation of Example 11, which contains gold leaf, improves the feeling of use, such as pleasantness when applied and good appearance. It can also be seen that the use of the skin topical preparation of Example 12, which contains pearl powder, improves the brightness of the skin. It can also be seen that the use of the skin topical preparation of Example 13, which contains collagen, improves the moist feeling and smoothness, etc. in particular. It can also be seen that the use of the skin topical preparation of Example 14, which contains hydrolyzed collagen, improves the ease of application, pleasantness, good appearance, etc. during use, and improves the moist feeling and smoothness of the skin after use. In addition, it is found that the use of the skin topical preparation of Example 15 containing placenta improves the smoothness and silky feeling after use.The use of Example 16 containing arbutin improves the ease of application, comfort, and spreadability during use, and improves the smoothness and brightness of the skin after use.

[0138] [Evaluation of Examples 14 to 17] <Skin condition measurement> In the sensory evaluation of the above [Evaluation of Examples 11 to 17], the amount of water evaporation (g / m2) at the intended application site on the inside of the forearm before application of the mixture was measured. 2 / hr) was measured using the following measuring device. After removing the mixture and washing with water, the amount of water evaporation (g / m2) at the site on the inside of the forearm where the mixture was applied was also measured. 2 / hr) was measured in the same manner.

[0139] Water Evaporation Rate (g / m 2 / hr): Measured using a Tewameter TM300 (manufactured by Courage+Khazaka). This measurement was performed using the standard method described in the instruction manual that came with the device. The average value for the three subjects was calculated from the measured values. The average value after use of the topical skin agent was divided by the average value before use to calculate the rate of change. The rate of change in the amount of water evaporation obtained is shown in Figure 6. The lower the rate of change, the higher the evaluation.

[0140] From the results of Fig. 6, it can be seen that the amount of water evaporation from the skin is further suppressed when using each of the skin preparations of Example 14, which further includes hydrolyzed collagen, Example 15, which includes placenta, and Example 16, which includes arbutin, in addition to the composition of Example 17. In particular, it can be seen that the suppression effect of Example 15, which includes placenta, is high.

[0141] <Examples 18 to 20> The components shown in Table 6 were blended and mixed in the compositions shown in the same table to produce powdered external skin preparations of Examples 18 to 20. The values ​​in Table 6 are the mass percentages (mass%) in the external skin preparations.

[0142] [Table 6]

[0143] [Evaluation of Examples 18 to 20] <Sensory evaluation> Five healthy women in their 20s to 30s were randomly selected as subjects. Otherwise, the same sensory evaluation as in (1) Sensory Evaluation in [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3] was conducted. However, the evaluation items were four items of "skin smoothness," "skin moistness," "skin moisture," and "skin softness" as skin condition after use. In addition, the subjects were asked to give a seven-point rating as shown in Table 2, with Example 20 being the standard (4.0 points). After tallying up, the average rating of the five subjects was calculated. The results are shown in Table 7.

[0144] [Table 7]

[0145] [Evaluation of Examples 18 and 19] <Skin condition measurement> In the sensory evaluation of the above [Evaluation of Examples 18 to 20], the moisture content of the keratin at the site on the inside of the forearm where the mixture was to be applied was measured using the above-mentioned measuring device before application of the mixture. Then, the mixture was removed and washed with water, and the moisture content of the keratin at the site on the inside of the forearm where the mixture was applied was similarly measured. From the measured values ​​obtained, the average value of the five subjects was calculated. The average value after use of the skin topical agent was divided by the average value before use, and the obtained value was taken as the rate of change. The results are shown in FIG. 7.

[0146] <Evaluation of topical skin preparations> Except for the fact that the amount of water used was 30 mL and the amount of the powdered skin topical preparation sample used was 10 g, the increase rate (%) in the volume of the mixture after stirring was determined in the same manner as in (3) <Foaming amount> in [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3]. The results are shown in Table 8 below.

[0147] [Table 8]

[0148] <Example 21> The components shown in Table 9 were blended and mixed in the compositions shown in the same table to produce the powdered topical skin preparation of Example 21. The values ​​in Table 9 are the mass percentages (mass%) in the topical skin preparation.

[0149] [Table 9]

[0150] <Comparative Example 4> The components listed in Table 10 were blended and mixed in the compositions shown in the same table to produce a powder containing carbonate and a liquid containing acid. The values ​​in Table 10 are in parts by mass. The viscosity of the obtained acid-containing liquid at 25°C was measured using a viscometer (Brookfield RVT model) and was found to be 16.9 mPa s.

[0151] [Table 10]

[0152] <Comparative Example 5> The components shown in Table 11 were blended and mixed in the compositions shown in the same table to produce a powder containing an acid and a viscous composition containing a carbonate. The values ​​in Table 11 are parts by mass. The viscosity of the obtained viscous composition at 25°C was measured using the above viscometer and found to be 549,600 mPa s.

[0153] [Table 11]

[0154] [Evaluation of Example 21 and Comparative Examples 4 and 5] (1) Sensory evaluation Four healthy women in their 20s and 30s were randomly selected and used as subjects. Otherwise, the same sensory evaluation as in (1) Sensory Evaluation in [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3] was performed. However, in Example 21, a powdered skin topical agent and water were mixed in a mass ratio of 1:2.7 to obtain a mixture. In Comparative Example 4, a powder containing carbonate and a liquid containing acid were mixed in a mass ratio of 1:3 to obtain a mixture. In Comparative Example 5, a powder containing acid and a viscous composition containing carbonate were mixed in a mass ratio of 1:3.68 to obtain a mixture. In addition, the evaluation items were two items of "skin elasticity" and "skin redness" as the skin condition after use of the skin topical agent, and the seven-point score shown in Table 2 was given with Comparative Example 4 as the standard (4.0 points). After compilation, the average evaluation points of the four people were calculated. The results are shown in Table 12. When the viscosity of the water used in Example 21 at 25° C. was measured using the above viscometer, the value was below the lower limit of the viscometer (10 mPa·s).

[0155] [Table 12]

[0156] (2) Skin condition measurement In the sensory evaluation in (1) above, before application of the mixture, the L* value was measured with the above-mentioned measuring device at the site on the inside of the forearm where the mixture was to be applied. After application, the mixture was removed and washed with water. At 15 minutes, 60 minutes, and 120 minutes after the end of removal, the L* value of the area on the inside of the forearm where the mixture was applied was measured using the above-mentioned measuring device. The average value of the four subjects was calculated from the measured values ​​obtained. The change value was determined by subtracting the average value before use from the average value after use of the skin topical agent. The change values ​​of the obtained L* value (whiteness) are shown in Table 13. In this table, the higher the change value, the higher the evaluation.

[0157] [Table 13]

[0158] As is clear from the descriptions in Tables 12 and 13, Example 21, in which a skin topical preparation containing an acidic substance, a carbon dioxide gas generating substance, and a polysaccharide or a derivative thereof is mixed with a water-containing substance, is more effective in improving the skin condition after use than Comparative Example 4, in which a powder containing a carbonate is mixed with a liquid containing an acid, and Comparative Example 5, in which a powder containing an acid is mixed with a viscous composition containing a carbonate.

[0159] <Examples 22 to 23> The components were blended and mixed in the proportions shown in Table 14 below to produce a powdered skin preparation. The values ​​in Table 14 are the mass percentages (mass%) in the topical skin preparation.

[0160] [Table 14]

[0161] [Evaluation of Examples 22 to 23] <Evaluation of storage stability> The powdered skin preparations obtained in Examples 22 and 23 were sealed in 9 g portions in aluminum film bags with the inside surface laminated with polyethylene terephthalate. The bags were stored at 50°C or 60°C for 2 months, and the presence or absence of carbon dioxide generation was observed during the storage period, using the presence or absence of swelling of the bags as an indicator. The results are shown in Table 15. In the table, "none" indicates that no carbon dioxide generation was observed during the storage period (2 months).

[0162] [Table 15]

[0163] As is clear from Table 15, in Examples 22 and 23, in which potato starch was blended at 10% by mass or more, no carbon dioxide gas was generated even after storage at 60°C for two months, confirming good storage stability.

[0164] <Example 24> The components were blended and mixed in the proportions shown in Table 16 below to produce a powdered skin preparation. The values ​​in Table 16 are the mass percentages (mass%) in the topical skin preparation.

[0165] [Table 16]

[0166] According to the procedure of Example 24 below, the properties of the skin topical preparations of the above Examples and Comparative Examples were evaluated.

[0167] [Evaluation of Example 24] <Anti-wrinkle function evaluation> Sixteen adult women with wrinkles at the corners of the eyes were selected as subjects. A powdered skin topical agent sample and water were mixed in a container at a ratio of 1:3 (by mass) to create a foam pack cosmetic mixture, which was then applied to a designated half of the face, centered on either the left or right corner of the eye. The mixture was removed 10 minutes after application, and the mixture was washed off with water or lukewarm water. The subjects performed this once a day for four weeks. To evaluate wrinkles, replicas were taken of the wrinkled areas at the corners of the left and right eyes of the subjects (with and without the mixture applied), and image analysis was performed using the replicas. Replicas were taken using a replica agent (SILFLO) in an area of ​​4 cm x 4 cm outward from the outer corner of the eye of the subject. The replicas obtained were analyzed in an area of ​​10 mm x 10 mm, starting from a point about 5 mm outward from the outer corner of the eye. The analysis was performed using a reflective replica analysis system (ASA-03RXD) and three-dimensional skin analysis software. The results of the maximum wrinkle maximum depth, which is the wrinkle evaluation result, are shown in Table 17. A positive change indicates that the wrinkles have become deeper compared to before use, whereas a negative change indicates that the wrinkles have become shallower compared to before use.

[0168] [Table 17]

[0169] From Table 17, it was confirmed that the use of the topical skin preparation of the present invention reduced the maximum depth of the maximum wrinkles at the corners of the eyes compared to when the preparation was not used. The above results show that the use of the foaming topical skin preparation of the present invention has the effect of making wrinkles less noticeable.

[0170] [Example of a prescription for a single-dose topical skin preparation] Specific examples of the formulation of the one-pack type external skin preparation of the present invention are given below.

[0171] <Example 25> A powdered one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 18. This one-component external skin preparation powder was placed in a container, and water was added in a mass ratio of 3 parts per 1 part of the powder and stirred, yielding a foam-like pack cosmetic.

[0172] [Table 18]

[0173] <Example 26> A powdered one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 19. This one-component external skin preparation powder was placed in a container, and water was added in a mass ratio of 5 parts by weight to 1 part by weight of the powder and stirred, yielding a foam-like pack cosmetic.

[0174] [Table 19]

[0175] <Example 27> A powdered one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 20. This one-component external skin preparation powder was placed in a container, and water was added (mass ratio: 10:1) to the powder and stirred, yielding a foam-like pack cosmetic.

[0176] [Table 20]

[0177] <Example 28> A powdered, one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 21. This one-component external skin preparation powder was placed in a container, and water was added in an amount of 3 parts by mass per 1 part of the powder and stirred, yielding a foam-like pack cosmetic.

[0178] [Table 21]

[0179] <Example 29> A powdered, one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 22. This one-component external skin preparation powder was placed in a container, and water was added (mass ratio: 4 parts by weight) to 1 part by powder and stirred, yielding a foam-like pack cosmetic.

[0180] [Table 22]

[0181] <Example 30> A powdered, one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 23. This one-component external skin preparation powder was placed in a container, and water was added (mass ratio: 10:1) to the powder and stirred, yielding a foam-like pack cosmetic.

[0182] [Table 23]

[0183] <Example 31> A powdered one-component external skin preparation was prepared by mixing the ingredients in the proportions shown in Table 24. This one-component external skin preparation powder was placed in a container, and water was added in a mass ratio of 4 parts by weight to 1 part by weight of the powder and stirred, yielding a foam-like pack cosmetic.

[0184] [Table 24]

[0185] <Example 32> A powdered one-component external preparation for the skin was prepared by mixing the ingredients in the proportions shown in Table 25. This one-component external preparation powder for the skin was placed in a container, and water was added in a mass ratio of 4 parts by weight to 1 part by weight of the powder and stirred, yielding a foam-like pack cosmetic.

[0186] [Table 25]

[0187] <Examples 2-1 to 2-28, Comparative Examples 2-1 and 2-2> The components shown in Table A below were blended and mixed in the compositions shown in the same table to produce powdered skin preparations of Examples 2-1 to 2-28 and powdered skin preparations of Comparative Examples 2-1 and 2-2. The values ​​in Table A below are the mass percentages (mass%) in the skin preparations. As the carboxymethylcellulose shown in Table A below, sodium carboxymethylcellulose was used. As the acrylic acid / alkyl methacrylate copolymer shown in Table A below, (acrylates / alkyl acrylate (C10-30)) crosspolymer was used. The "pattern" in Table A indicates which of the above (1) to (3) relating to the combination of two or more polysaccharides or their derivatives, or the above (4) relating to the combination of a polysaccharide or its derivative with an inorganic or organic thickening compound, applies. This classification is also shown in Table C below.

[0188] [Table A]

[0189] The properties of the skin topical preparations of <Examples 2-1 to 2-28, Comparative Examples 2-1 and 2-2> with the formulations in Table A above were evaluated in the same manner as the sensory evaluation in (1) of [Evaluation of Examples 1 to 10 and Comparative Examples 1 to 3] described above. However, the questionnaire items were as shown in (1) to (19) of Table C below. The results are shown in Table C below. The evaluation criteria were absolute evaluation on a 7-point scale as shown in Table B below. In Table C, "(4) Fineness of bubbles" was given a higher rating the finer the bubbles. "(10) Carbonation (popping)" was given a higher rating the stronger the popping. "(11) Duration of carbonation (popping)" was given a higher rating the longer the carbonation was sustained. "(12) Skin firming" was given a higher rating the stronger the skin firming.

[0190] [Table B]

[0191] [Table C]

[0192] In Table C, CMC is an abbreviation for sodium carboxymethylcellulose, tamarind is an abbreviation for tamarind gum, HPMC is an abbreviation for hydroxypropyl methylcellulose, HEC is an abbreviation for hydroxyethyl cellulose, grafted starch is an abbreviation for sodium acrylate grafted starch, acrylic acid is an abbreviation for acrylic acid-alkyl methacrylate copolymer, and PVP is an abbreviation for polyvinylpyrrolidone.

[0193] As is clear from the results of Table C, the skin preparations of Examples 2-1 to 2-28 corresponding to any of (1) to (4) are evaluated as being easy to mix, easy to dissolve, easy to remove, and skin brightness, and are superior in terms of fineness of foam, uniformity, ease of application, foam elasticity, foam retention, carbonation, carbonation persistence, moist skin, skin elasticity, skin redness, smooth skin, smooth skin, and skin tightening, compared with the skin preparations of Comparative Examples 2-1 and 2-2 that use a combination of conventional polysaccharides or their derivatives.Therefore, it is clear that the effect of "good feeling when used and improving skin condition" associated with the skin preparations of the present invention corresponding to any of (1) to (4) is remarkable.

[0194] The L* value, stratum corneum moisture content (μS), and elasticity before and after use of the topical skin preparations of <Examples 2-1 to 2-28, Comparative Examples 2-1 and 2-2> with the formulations in Table A above were measured using the same method as described in "(2) Measurement of skin condition" in [Evaluation of Examples 1 to 10, Comparative Examples 1 to 3] above. The ratio of the measured value after use to the measured value before use of the topical skin preparation was calculated for the obtained L* value, stratum corneum moisture content, and elasticity, and this was used as the rate of change. The results are shown in Figures 8 to 10. In addition, the amount of water evaporation (g / m2) before and after use of the topical skin preparations of <Examples 2-1 to 2-28, Comparative Examples 2-1 and 2-2> with the formulations in Table A above was measured. 2 / hr) was measured in the same manner as described in "<Skin condition measurement>" in [Evaluation of Examples 14 to 17] above. The ratio of the measured value after use of the skin topical preparation to the measured value before use was calculated and used as the rate of change. The results are shown in FIG.

[0195] As is clear from the results of Figures 8 to 10, the elasticity change rate of the skin topical preparations of Examples 2-1 to 2-28 corresponding to any of (1) to (4) was equal to or greater than that of the skin topical preparation of Comparative Example 2-2, and was higher than that of Comparative Example 2-1. In addition, the L* value and stratum corneum moisture content change rate of the skin topical preparations of Examples 2-1 to 2-28 were superior to both Comparative Examples 2-1 and 2-2. Therefore, it is clear that the effect of "improving the skin condition" of the skin topical preparation of the present invention corresponding to any of (1) to (4) is remarkable.

Claims

1. A foamable skin preparation for external use, comprising at least a solid acidic substance and a solid carbon dioxide gas generating substance which reacts with the acidic substance to generate carbon dioxide gas, further comprising: At least one polysaccharide or derivative thereof; Contains an anti-inflammatory agent, The foaming skin preparation is mixed with water when used.

2. A one-component type foamable skin preparation for external use, comprising at least a solid acidic substance and a solid carbon dioxide gas generating substance which reacts with the acidic substance to generate carbon dioxide gas, further comprising: At least one polysaccharide or derivative thereof; Contains an anti-inflammatory agent, The foamable skin preparation is mixed with a water-containing substance having a viscosity of 50,000 mPa·s or less when used.

3. 3. The foamable skin preparation according to claim 1, wherein the anti-inflammatory agent is at least one selected from the group consisting of allantoin, stearyl glycyrrhetinate, licorice and aloe.

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