Composition for external use on skin containing ascorbic acid and / or its salt

Abstract

Provided is a composition for external use on the skin which is excellent in terms of use feeling and appearance.　The purpose of the present invention is to provide a composition for external use on the skin which has satisfactory use feeling, that is, good slipperiness, and is reduced in coloration. The composition for external use on the skin comprises (A) at least one compound selected from the group consisting of ascorbic acid and salts of ascorbic acid, (B) at least one compound selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and (C) a diol having three carbon atoms, the content of which is 1-50 mass%.

Description

[Technical Field]

[0001] The present invention relates to a composition for external use on the skin containing ascorbic acid and / or a salt thereof. [Background technology]

[0002] Ascorbic acid is known to exert various effects, such as anti-inflammatory effects, acne-reducing effects, whitening effects, anti-aging effects, antioxidant effects, cell activation effects by promoting the synthesis of biological components such as collagen, and effects of suppressing cell damage and DNA damage caused by ultraviolet rays in epidermal keratinocytes, and is used as an external skin preparation in anticipation of these effects. Techniques for improving the stability of such ascorbic acid have been proposed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-225865 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide an ascorbic acid-containing external skin composition that has a good feel when used and a good appearance. [Means for solving the problem]

[0005] According to the investigations of the present inventors, it has been found that when a composition containing ascorbic acid and / or a salt thereof is used as an external skin preparation, it may be difficult to achieve both a good feel in use and a good appearance.

[0006] As a result of intensive research into solving the problem, the present inventors have found that a composition comprising: (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and The present inventors have found that a skin external application composition excellent in feel and appearance can be obtained by incorporating 1 to 50% by mass of (C) a diol having 3 carbon atoms, and have thus completed the present invention.

[0007] That is, the present invention provides the following external skin compositions. Section 1. A composition for external use on skin containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and (C) 1 to 50% by mass of a diol having 3 carbon atoms. Section 2. Item 2. The composition for external use on skin according to Item 1, wherein the concentration of the component (A) is 1 to 10% by mass. Section 3. Item 3. The composition for external use on skin according to Item 1 or 2, wherein the concentration of the component (B) is 0.001 to 2% by mass. Section 4. Item 4. The composition for external application to skin according to any one of Items 1 to 3, further comprising (D) 1 to 15% by mass of water. Section 5. Item 5. The composition for external use on skin according to any one of Items 1 to 4, further comprising 1 to 20% by mass of (E) a lower alcohol. Section 6. Item 6. The composition for external use on skin according to any one of Items 1 to 5, which has a pH of 2 to 5.

[0008] Furthermore, the present invention provides the following methods for topical skin application compositions. Section 7. A method for inhibiting discoloration of a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, by blending (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and 1 to 50% by mass of (C) a diol having 3 carbon atoms. Section 8. A discoloration inhibitor for a composition comprising (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, and containing (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and (C) 1 to 50% by mass of a diol having 3 carbon atoms. Section 9. A method for improving the feel when used in a topical skin composition containing at least one selected from the group consisting of (A) ascorbic acid and salts of ascorbic acid, by using (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and (C) 1 to 50% by mass of a diol having 3 carbon atoms. Section 10. A usability improver for a composition comprising (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, which contains (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and (C) 1 to 50% by mass of a diol having 3 carbon atoms. [Effects of the Invention]

[0009] According to the present invention, a composition for external use on skin that is excellent in both feel and appearance can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this specification, the unit of content "% by mass" is synonymous with "g / 100g".

[0011] [Skin external composition] The composition for external use on skin of the present invention comprises: (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) A composition for external use on skin containing 1 to 50% by mass of a diol having 3 carbon atoms.

[0012] ((A) At least one selected from the group consisting of ascorbic acid and salts of ascorbic acid) The ascorbic acid used in the present invention may be any ascorbic acid commercially available as a component of pharmaceuticals, quasi-drugs, or topical skin preparations in the field of cosmetics, and although not limited thereto, these generally refer to the L-isomer.

[0013] Salts of ascorbic acid can also be used. Here, the salt of ascorbic acid refers to a pharmaceutically acceptable salt. Examples include, but are not limited to, salts with organic bases (e.g., salts with tertiary amines such as trimethylamine salt, triethylamine salt, monoethanolamine salt, triethanolamine salt, and pyridine salt, basic ammonium salts such as arginine, etc.), salts with inorganic bases (e.g., alkali metal salts such as ammonium salt, sodium salt, and potassium salt, alkaline earth metal salts such as calcium salt and magnesium salt, aluminum salt, etc.). Preferred salts of ascorbic acid are sodium salt and potassium salt.

[0014] In the present invention, ascorbic acid or a salt thereof can be used alone or in combination of two or more. From the viewpoint of significantly exhibiting the effects of the present invention, ascorbic acid is preferred. (A) Ascorbic acid or a salt thereof may be synthesized and used, or a commercially available product may be used.

[0015] In the topical skin composition of the present invention, the total content of component (A) relative to the total amount of the topical skin composition is appropriately determined depending on the balance with other components.

[0016] The total content of component (A) relative to the total amount of the topical skin composition is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 7% by mass or less, and even more preferably 5% by mass or less. The total content of component (A) relative to the total amount of the topical skin composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, and even more preferably 3% by mass or more. The total content of component (A) relative to the total amount of the topical skin composition is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, even more preferably 2 to 9% by mass, and even more preferably 3 to 5% by mass.

[0017] ((B) At least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid) The salicylic acid or a derivative of salicylic acid used in the present invention is not particularly limited as long as it is used as a component of a pharmaceutical, quasi-drug or external skin preparation in the field of cosmetics.

[0018] Salts of salicylic acid can also be used. Here, the salts of salicylic acid are pharmaceutically acceptable salts. Examples include, but are not limited to, alkali metal salts, alkaline earth metal salts, and salts with organic bases. Examples of salicylate salts include at least one selected from the group consisting of sodium salicylate, calcium salicylate, magnesium salicylate, and potassium salicylate.

[0019] From the viewpoint of significantly achieving the effects of the present invention, at least one selected from the group consisting of salicylic acid, sodium salicylate, calcium salicylate, magnesium salicylate, and potassium salicylate is preferred, and salicylic acid and / or sodium salicylate are more preferred. In another embodiment, a derivative of salicylic acid can also be used as component (B). Examples of such derivatives of salicylic acid include, but are not limited to, ethylene glycol salicylate, phenyl salicylate, methyl salicylate, 2-ethylhexyl salicylate, dipropylene glycol salicylate, and titanium salicylate. (B) Salicylic acid, a salt of salicylic acid, or a derivative of salicylic acid may be synthesized or commercially available.

[0020] In the topical skin composition of the present invention, the total content of component (B) relative to the total amount of the topical skin composition is not limited, but is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, and even more preferably 0.05% by mass or more. The total content of component (B) relative to the total amount of the topical skin composition is not limited, but is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.5% by mass or less.

[0021] The total content of component (B) relative to the total amount of the composition for external use on skin is preferably 0.001 to 5% by mass, preferably 0.005 to 2% by mass, more preferably 0.01 to 1% by mass, and even more preferably 0.05 to 0.5% by mass. In addition, taking into account cases where the composition is used as an acne medication, the total content may be 0.001 to 5% by mass, 0.01 to 4% by mass, 0.1 to 3% by mass, 0.5 to 2% by mass, etc.

[0022] In the topical skin composition of the present invention, the ratio of the amount of component (B) to component (A) is not particularly limited, but is preferably 0.0002 to 10 parts by mass, more preferably 0.001 to 1 part by mass, even more preferably 0.005 to 0.25 parts by mass, and even more preferably 0.01 to 0.2 parts by mass, per 1 part by mass of the total content of component (A).

[0023] ((C) Diol with 3 carbon atoms) The diol having three carbon atoms used in the present invention is not particularly limited as long as it is used as a component of topical skin preparations in the fields of pharmaceuticals, quasi-drugs, or cosmetics. Furthermore, commercially available diols having three carbon atoms can also be used as they are. Examples of diols having three carbon atoms include, but are not limited to, 1,3-propanediol (CAS No.: 504-63-2, English name: 1,3-Dihydroxypropane or Trimethylene Glycol) and propylene glycol (CAS No.: 57-55-6, English name: 1,2-Dihydroxypropane, Japanese name: 1,2-Propanediol). These diols may be used alone or in appropriate combination. From the viewpoints of reducing skin irritation, improving usability, and suppressing discoloration, a combination of 1,3-propanediol and propylene glycol is also a preferred embodiment, and it is more preferred that component (C) contain at least 1,3-propanediol.

[0024] In the topical skin composition of the present invention, the total content of component (C) relative to the total amount of the topical skin composition is 1% by mass or more, preferably 5% by mass or more, and more preferably 10% by mass or more. The total content of component (C) relative to the total amount of the external skin composition is 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.

[0025] The total content of component (C) relative to the total amount of the external skin composition is 1 to 50 mass %, preferably 5 to 40 mass %, and more preferably 10 to 30 mass %.

[0026] In the topical skin composition of the present invention, the ratio of the amount of component (C) to the amount of component (A) is not particularly limited, but is preferably 0.05 to 100 parts by mass, more preferably 0.5 to 40 parts by mass, and even more preferably 1 to 15 parts by mass, per part by mass of the total content of component (A).

[0027] The amount of propylene glycol in the component (C) is 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the topical skin composition. The amount of propylene glycol is preferably 50% by mass or less, 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. The total content of propylene glycol relative to the total amount of the external skin composition is 0.1 to 50 mass%, 0.5 to 40 mass%, 1 to 40 mass%, preferably 5 to 30 mass%, and more preferably 10 to 20 mass%.

[0028] In the topical skin composition of the present invention, the ratio of the amount of propylene glycol to the amount of component (A) is not particularly limited, but is preferably 0.05 to 80 parts by mass, more preferably 0.5 to 30 parts by mass, and even more preferably 1 to 10 parts by mass, per part by mass of the total content of component (A).

[0029] The amount of 1,3-propanediol in the component (C) is 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the topical skin composition. The amount of 1,3-propanediol is 50% by mass or less, 40% by mass or less, 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0030] The total content of 1,3-propanediol relative to the total amount of the external skin composition is 0.1 to 50 mass%, 0.5 to 40 mass%, 1 to 30 mass%, preferably 5 to 20 mass%, and more preferably 10 to 15 mass%.

[0031] In the topical skin composition of the present invention, the ratio of the amount of 1,3-propanediol to the amount of component (A) is not particularly limited, but is preferably 0.05 to 60 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 7.5 parts by mass, per part by mass of the total content of component (A).

[0032] In the topical skin composition of the present invention, component (C) may contain both propylene glycol and 1,3-propanediol. In this case, the combined amount of propylene glycol and 1,3-propanediol may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, or may be 50% by mass or less, 45% by mass or less, 40% by mass or less, or 35% by mass or less. The combined amount of propylene glycol and 1,3-propanediol relative to the total amount of the composition for external use on skin may be 10 to 50% by mass, 15 to 45% by mass, 20 to 40% by mass, or 25 to 35% by mass. When both propylene glycol and 1,3-propanediol are blended, the amounts may be 5 to 25 mass%, 5 to 20 mass%, 5 to 15 mass%, 10 to 25 mass%, 10 to 20 mass%, 10 to 15 mass%, 15 to 25 mass%, 15 to 20 mass%, etc.

[0033] The topical skin composition of the present invention may contain (D) water and / or (E) a lower alcohol in addition to the above-mentioned components (A), (B), and (C), as long as the effects of the present invention are not impaired.

[0034] ((D)Wed) The composition for external use on skin of the present invention may contain water. The proportion of water is not limited, but the content of water relative to the total amount of the composition for external use on skin is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 2 to 15% by mass.

[0035] In the topical skin composition of the present invention, the ratio of component (D) to component (A) is preferably 0.005 to 60 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.2 to 7.5 parts by mass, per part by mass of the total content of component (A).

[0036] ((E) Lower alcohol) The topical skin composition of the present invention may contain a lower alcohol. The lower alcohol used in the present invention is not particularly limited as long as it is used as a component of topical skin preparations in the fields of pharmaceuticals, quasi-drugs, or cosmetics. In this specification, the term "lower alcohol" refers to a C1-C6 alcohol. Among these, C1-C3 alcohols are particularly preferred. Examples of such alcohols include methanol, ethanol, n-propanol, and isopropanol, with ethanol being particularly preferred.

[0037] In the topical skin composition of the present invention, the total content of component (E) relative to the total amount of the topical skin composition, if present, is preferably 0.1 to 40% by mass, more preferably 0.5 to 10% by mass, and even more preferably 1 to 7% by mass.

[0038] Furthermore, although not limited thereto, typically, in the topical skin composition of the present invention, the amount of ethanol relative to the total amount of the topical skin composition is preferably 1 to 40% by mass, more preferably 2 to 30% by mass, and even more preferably 3 to 20% by mass.

[0039] In the topical skin composition of the present invention, the ratio of the amount of component (E) to the amount of component (A) is preferably 0.005 to 80 parts by mass, more preferably 0.05 to 10 parts by mass, and even more preferably 0.1 to 3.5 parts by mass, per 1 part by mass of the total content of component (A).

[0040] (Polyhydric alcohol) The external skin composition of the present invention may contain a polyhydric alcohol in addition to the above components (A), (B), and (C), as long as it does not impair the effects of the present invention.

[0041] The polyhydric alcohol used in the present invention is not particularly limited as long as it is used as a component of a topical skin preparation in the fields of pharmaceuticals, quasi-drugs, or cosmetics. The polyhydric alcohol may be added for moisturizing purposes or as a solubilizer, but is not limited thereto. Specific examples include glycerin, diglycerin, dipropylene glycol, 1,3-butylene glycol, and 3-methyl-1,3-butanediol.

[0042] When included, the total content of polyhydric alcohols other than component (C) relative to the total amount of the topical skin composition of the present invention is preferably 0.1 to 60 mass%, more preferably 1 to 50 mass%, and even more preferably about 10 to 45 mass%.

[0043] (Vitamin E) The topical skin composition of the present invention may contain, in addition to the above-mentioned components (A), (B), and (C), vitamin E compounds such as tocopherol, tocopherol salts, and tocopherol derivatives, as long as the effects of the present invention are not impaired. The tocopherol, tocopherol salts, and tocopherol derivatives used in the present invention may be compounds commonly used as components of topical skin preparations in the fields of pharmaceuticals, quasi-drugs, and cosmetics, and may be in any of the d-, l-, or dl-forms and may have any of the α, β, γ, and δ structures. Examples of tocopherols include d-α-tocopherol, d-β-tocopherol, d-γ-tocopherol, d-δ-tocopherol, l-α-tocopherol, l-β-tocopherol, l-γ-tocopherol, l-δ-tocopherol, and mixtures thereof such as dl-α-tocopherol, dl-β-tocopherol, dl-γ-tocopherol, and dl-δ-tocopherol. Tocopherol derivatives are not limited to, but are preferably tocopherol esters. Particularly, examples of tocopherol derivatives include tocopherol acetate, tocopherol nicotinate or a salt thereof, tocopherol succinate or a salt thereof, tocopherol linoleate, tocopherol phosphate or a salt thereof, tocopherol (linoleate / oleate), and tocopherol linoleate.

[0044] In the composition for external use on skin of the present invention, the total content of vitamin E relative to the total amount of the composition for external use on skin is not particularly limited, but is preferably 0.00001 to 10% by mass, more preferably 0.0001 to 5% by mass.

[0045] (Ascorbic acid derivatives) The topical skin composition of the present invention may contain an ascorbic acid derivative in addition to the above-mentioned components (A), (B), and (C), as long as the effects of the present invention are not impaired. Examples of the ascorbic acid derivative used in the present invention include 3-O-ethyl ascorbic acid, L-ascorbic acid 2-glucoside, dehydroascorbic acid, sodium ascorbic acid phosphate, magnesium ascorbic acid phosphate, sodium ascorbic acid monophosphate, sodium ascorbic acid diphosphate, sodium ascorbic acid triphosphate, sodium ascorbic acid 2-sulfate, and salts thereof.

[0046] The salt is a pharmaceutically acceptable salt. Examples of the salt include, but are not limited to, salts with organic bases (e.g., salts with tertiary amines such as trimethylamine salt, triethylamine salt, monoethanolamine salt, triethanolamine salt, pyridine salt, etc., basic ammonium salts such as arginine, etc.), salts with inorganic bases (e.g., alkali metal salts such as ammonium salt, sodium salt, potassium salt, etc., alkaline earth metal salts such as calcium salt, magnesium salt, etc., aluminum salt, etc.). Particularly preferred salts of 3-O-ethylascorbic acid are sodium salt and potassium salt.

[0047] In the present invention, these ascorbic acid derivatives may be used alone or in combination of two or more.

[0048] In the topical skin composition of the present invention, the total content of the ascorbic acid derivative relative to the total amount of the topical skin composition is preferably 0.005 to 10% by mass, more preferably 0.01 to 5% by mass, even more preferably 0.02 to 3% by mass, and even more preferably 0.05 to 2% by mass.

[0049] (surfactant) The topical skin composition of the present invention may contain a surfactant as long as it does not impair the effects of the present invention. When a surfactant is contained, it is not limited, but a nonionic surfactant is preferred, for example, polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 60, polyoxyethylene hydrogenated castor oil 80, polyoxyethylene polyoxypropylene decyl tetradecyl ether, polyoxyethylene (20) polyoxypropylene (4) cetyl ether, polyoxyethylene (10) cetyl ether, polyoxyethylene (10) polyoxypropylene (4) cetyl ether, polyoxyethylene (10) oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene isoalcohol ether, PEG-8 glyceryl isostearate, polyoxyethylene sorbitan (20E.O.) monolaurate, polyoxyethylene sorbitan (20E.O.) isostearate, polyoxyethylene sorbitan (20E.O.) stearate, polyoxyethylene sorbitan (20E.O.) stearate. ), coconut oil fatty acid polyglyceryl-10, coconut oil fatty acid polyglyceryl-3, coconut oil fatty acid PEG-7 glyceryl, dioleate polyglyceryl-10, diisostearate polyglyceryl-10, triisostearate PEG-40 glyceryl isostearate, trilaurate polyglyceryl-10, tricaprylate hexaglyceryl, laurate polyglyceryl, myristate polyglyceryl, polyoxyethylene lauryl ether, etc. can be used, and polyoxyethylene polyoxypropylene decyl tetradecyl ether, polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 60, polyoxyethylene hydrogenated castor oil 80, polyoxyethylene sorbitan isostearate (20E.O.), polyoxyethylene sorbitan monolaurate (20E.O.), polyglyceryl laurate are particularly preferred.

[0050] In the topical skin composition of the present invention, the total content of surfactants relative to the total amount of the topical skin composition is appropriately set depending on the balance with other components, and is preferably 0.001 to 10% by mass, more preferably 0.005 to 7% by mass, and even more preferably 0.01 to 5% by mass.

[0051] (Other ingredients) In addition to the components (A), (B), and (C) described above, the topical skin composition of the present invention may further contain one or more of a variety of ingredients, such as whitening ingredients, anti-inflammatory ingredients, antibacterial ingredients, cell activating ingredients, astringent ingredients, antioxidant ingredients, acne-reducing ingredients, anti-aging ingredients, ingredients promoting biocomponent synthesis such as collagen, blood circulation promoting ingredients, moisturizing ingredients, and anti-aging ingredients, in combination, to enhance or complement the various effects of ascorbic acid or to impart other useful effects. Preferred are one or more of the whitening ingredients, anti-inflammatory ingredients, antibacterial ingredients, cell activating ingredients, astringent ingredients, antioxidant ingredients, anti-aging ingredients, and moisturizing ingredients. Particularly preferred combinations of these ingredients include a combination with a whitening ingredient, a combination of a whitening ingredient and an antioxidant ingredient, combinations with an antioxidant ingredient, combinations with an anti-aging ingredient, and combinations of a whitening ingredient and an anti-aging ingredient. These components are not particularly limited as long as they have been used as components of topical skin preparations in the fields of pharmaceuticals, quasi-drugs, or cosmetics, or will be used in the future, and any components can be appropriately selected and used. Among these, isopropylmethylphenol, a bactericidal component, and / or dipotassium glycyrrhizinate, an anti-inflammatory component, are particularly preferred.

[0052] In addition to the above-mentioned components, the topical skin composition of the present invention may further contain a solubilizing component, oils and fats, sugars, or a transdermal absorption-promoting component. In particular, the inclusion of a solubilizing component or oils and fats can further improve the stability, efficacy, and usability of ascorbic acid in an aqueous solvent.

[0053] The topical skin composition of the present invention may contain, as needed, various ingredients commonly used as ingredients in topical preparations in the fields of pharmaceuticals, quasi-drugs, and cosmetics, such as amino acids, irritation-reducing agents, thickeners, preservatives, UV protection agents, colorants, dispersants, additional pH adjusters, fragrances, etc., within quantitative and qualitative ranges that do not impair the qualities such as appearance stability and viscosity, or that do not impair the effects of the present invention. These ingredients may be used alone, or two or more may be used in combination.

[0054] (form) The topical skin composition of the present invention can be prepared in various desired forms, such as paste, mousse, gel, liquid, emulsion, cream, sheet (supported by a substrate), aerosol, spray, etc., by blending and mixing components (A), (B), and (C) and, if necessary, the above-mentioned optional components, and further blending, if necessary, other solvents or bases for commonly used topical preparations. These can be produced by conventional methods in the art.

[0055] The topical skin composition of the present invention is particularly preferably a transparent or translucent composition in which ascorbic acid and / or a salt thereof has been solubilized. Here, "solubilized" is defined as follows: For example, it refers to a composition in which the transmittance at a wavelength of 700 nm measured using a spectrophotometer or a UV-2450 photoelectric photometer (Shimadzu Corporation) is 80 to 100%, preferably 85 to 100%, and more preferably 90 to 100% by ultraviolet-visible absorbance measurement. Here, the transmittance of water is defined as 100%. The solubilized composition of the present invention has a transparent or translucent appearance. The transmittance measurement method is more specifically in accordance with the method described in the 16th Edition of the Japanese Pharmacopoeia [B], General Test Methods, Section 2. Physical Test Methods, Spectroscopic Measurement Methods, Section 2.24, Ultraviolet-Visible Absorbance Measurement Method.

[0056] (viscosity) The topical skin composition of the present invention can be prepared as a composition with the appropriate viscosity desired for use, particularly when applied to the skin. The viscosity of the topical skin composition of the present invention is not particularly limited, but is typically about 1 to 300 mPa·s, preferably about 1 to 200 mPa·s, more preferably about 1 to 100 mPa·s, and most preferably about 1 to 50 mPa·s, as measured at 25°C using an E-type viscometer. The viscosity measurement method is more specifically in accordance with the method described in the 16th Edition of the Japanese Pharmacopoeia [B], General Test Methods, Section 2. Physical Test Methods, Other Physical Test Methods, Section 2.53, Viscosity Measurement Method, Section 2. Method 2, Rotational Viscometer Method, Section 2.1.3, Cone-Plate Rotational Viscometer.

[0057] (pH) The composition for external use on skin of the present invention may generally have a pH of 1 to 8, but from the viewpoints of the stability of ascorbic acid, low irritation to the skin and mucous membranes, and a pleasant feel on the skin, the pH is preferably 2 to 7, more preferably 2 to 6, even more preferably 2 to 5.0, and most preferably 2 to 4.5. An acidic range is desirable.

[0058] (Application) The topical skin composition of the present invention is particularly effective as a whitening agent, anti-inflammatory agent, and anti-aging agent, and has, for example, acne prevention and treatment and antioxidant effects. Furthermore, when applied to the skin, it may have the effects of increasing skin transparency, maintaining moisture, improving skin texture, and reducing roughness. Furthermore, it may have the effects of moisturizing skin with acne scars and pores, making pores less noticeable, leading to smooth skin, and moisturizing the skin, and it can also be used to prevent and treat age spots.

[0059] The topical skin composition of the present invention can be various skin compositions belonging to the fields of cosmetics, topical pharmaceuticals, or topical quasi-drugs, such as basic cosmetics such as serums, lotions, sunscreen creams, emulsions, creams, lotions, oils, and packs; makeup cosmetics such as foundations, lipsticks, lip balms, mascaras, eye shadows, eyeliners, eyebrow pencils, and nail polish; cleansers such as face washes, cleansers, and body washes; and various skin compositions belonging to the fields of cosmetics, topical pharmaceuticals, and topical quasi-drugs, such as anti-armpit odor agents, athlete's foot treatments, antipruritics, wound healing agents, cleansing agents, cleansers, anti-inflammatory and analgesic agents, acne treatments, hemorrhoid treatments, germicides, disinfectants, whitening agents, and UV protection agents. Due to its effects on the skin, the present invention is preferably used in products applied to the skin, such as topical skin preparations (preparations for the skin). The composition of the present invention can be administered in a known or commonly used dosage and administration regimen, from once to several times daily, depending on the intended use.

[0060] [Coloring suppression method] The present invention also encompasses a method for inhibiting discoloration of a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid. According to the method for inhibiting discoloration of the present invention, a stable formulation containing ascorbic acid and inhibiting discoloration can be obtained by incorporating (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms. Specifically, the present invention relates to a method for inhibiting discoloration of a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, by incorporating (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having three carbon atoms. Here, "inhibition of discoloration" refers to, but is not limited to, the inhibition of discoloration due to ascorbic acid during storage (including improved transparency). Such discoloration inhibition allows the topical skin composition of the present invention to exhibit a good appearance. Furthermore, the good appearance achieved by such discoloration inhibition also includes, for example, the absence of discoloration when the formulation comes into contact with clothing, etc.

[0061] In the present invention, the topical skin composition for inhibiting discoloration contains (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms, and the contents thereof are the same as those used in the above-mentioned topical skin composition.

[0062] [Coloration inhibitor] The present invention also includes a discoloration inhibitor for a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid. The discoloration inhibitor of the present invention is a discoloration inhibitor for a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, and also containing (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and 1 to 50% by mass of (C) a diol having 3 carbon atoms.

[0063] The discoloration inhibitor of the present invention is a composition for external use on skin that contains (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms, and the contents thereof are the same as those used in the above-mentioned composition for external use on skin.

[0064] [How to improve usability] The present invention also encompasses a method for improving the feel of use of a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid. According to the method for improving the feel of use of the present invention, a good feel of use can be achieved by incorporating (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms. Specifically, the present invention relates to a method for imparting a good feel of use to a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid by incorporating (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms. Here, the feeling of use refers to, but is not limited to, low friction and smooth application.

[0065] In the method for improving the sensation of use of the present invention, the topical skin composition contains (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms, and the contents thereof and the like are the same as those used in the topical skin composition described above.

[0066] [Usage improver] The present invention also includes a usability improver for a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid. The usability improver of the present invention is a usability improver for a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, and also containing (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid, and (C) 1 to 50% by mass of a diol having 3 carbon atoms.

[0067] The usability improver of the present invention is a composition for topical skin application that contains (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) at least one selected from the group consisting of salicylic acid, salts of salicylic acid, and derivatives of salicylic acid; and (C) 1 to 50% by mass of a diol having 3 carbon atoms, and the contents thereof and the like are the same as those used in the above-mentioned composition for topical skin application. [Example]

[0068] Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples. Note that the unit of the amount of each component in the tables is % by mass unless otherwise specified in the tables.

[0069] Compositions for external use on the skin having the compositions shown in Tables 1 to 4 were prepared according to a conventional method.

[0070] [Test Example 1: Ascorbic Acid Color Inhibition Confirmation Test] The compositions of the reference example, comparative example, and working examples were evaluated for the presence or absence of inhibition of discoloration after storage at 60°C by visual inspection and a color difference meter. Specifically, the various components were mixed and dissolved according to the formulations shown in the tables to prepare the compositions. 10 mL of the prepared composition was filled into a 20 mL screw-cap bottle and allowed to stand in a thermostatic chamber at 60°C for 5 days. After the 5-day measurement period had elapsed, the screw-cap bottle was removed from the thermostatic chamber and allowed to stand at 25°C before evaluation. Each composition was subjected to measurement to determine the presence and degree of discoloration. Measurements were performed using a spectrophotometer CM-5 (Konica Minolta, Inc.) by placing 2.5 mL of the test solution in a glass cell (CM-A97, 2 mm thick) and measuring the L, a, and b values ​​in the CIELAB color system at 25°C. ΔL*Δa*Δb* values ​​were measured using purified water as the blank.

[0071] The L* value (ΔL*) is a value relating to lightness, the a* value (Δa*) is a value relating to both directions between red and green, and the b* value (Δb*) is a value relating to both directions between yellow and blue.

[0072] ΔE*ab is expressed by the following formula and is an index representing the overall degree of coloration of the composition of the Examples or Comparative Examples.

[0073]

number

[0074] The ΔL increase rate was calculated using the following formula: ΔL increase rate = ΔL(D65)(after storage) / ΔL(D65)(before storage)

[0075] The Δa increase rate was calculated using the following formula. Δa increase rate = Δa(D65)(after saving) / Δa(D65)(before saving)

[0076] The Δb increase rate was calculated using the following formula. Δb increase rate = Δb(D65)(after saving) / Δb(D65)(before saving)

[0077] The ΔE*ab increase rate was calculated using the following formula: where (D65) indicates that a D65 light source was used. ΔE*ab(D65) increase rate = ΔE*ab(D65) (after storage) / ΔE*ab(D65) (before storage)

[0078] [Table 1]

[0079] Here, the improvement rate (%) of Δa*(D65) in Example 1-1 is expressed as {(increase rate of Δa*(D65) in Reference Example 1-1 - increase rate of Δa*(D65) in Example 1-1) / (increase rate of Δa*(D65) in Reference Example 1-1)} × 100. The improvement rate (%) of Δa*(D65) in Comparative Example 1-1 is expressed as {(increase rate of Δa*(D65) in Reference Example 1-2 - increase rate of Δa*(D65) in Comparative Example 1-1) / (increase rate of Δa*(D65) in Reference Example 1-2)} × 100. The improvement rate (%) of Δb*(D65) in Example 1-1 is expressed as {(increase rate of Δb*(D65) in Reference Example 1-1 - increase rate of Δb*(D65) in Example 1-1) / (increase rate of Δb*(D65) in Reference Example 1-1)} × 100. The improvement rate (%) of Δb*(D65) in Comparative Example 1-1 is expressed as {(increase rate of Δb*(D65) in Reference Example 1-2 - increase rate of Δb*(D65) in Comparative Example 1-1) / (increase rate of Δb*(D65) in Reference Example 1-2)}×100.

[0080] Regarding the Δa value, the composition of Example 1-1 containing 30% by mass of 1,3-propanediol had a color closer to that of water than Reference Example 1-1 due to the addition of salicylic acid. On the other hand, in the system containing 60% by mass of 1,3-propanediol, the addition of salicylic acid caused the color to move away from that of water compared to Reference Example 1-2. Regarding the Δb value, the composition of Example 1-1 containing 30% by mass of 1,3-propanediol exhibited a discoloration suppression effect due to salicylic acid. On the other hand, the composition of Comparative Example 1-1 containing 60% by mass of 1,3-propanediol did not exhibit a discoloration suppression effect and exhibited a worsening effect. The addition of salicylic acid further suppressed discoloration in the composition of Example 1-1. Furthermore, the composition of Comparative Example 1-1 was significantly inferior to the composition of Example 1-1 in all of the evaluated indices.

[0081] [Table 2] [Table 3]

[0082] Here, the improvement rate (%) of ΔL*(D65) for each example is expressed as {(increase rate of ΔL*(D65) for each reference example - increase rate of ΔL*(D65) for each example) / increase rate of ΔL*(D65) for each reference example} x 100. The improvement rate (%) of ΔL*(D65) of the comparative example is expressed as {(increase rate of ΔL*(D65) of the reference example - increase rate of ΔL*(D65) of the comparative example) / increase rate of ΔL*(D65) of the reference example} × 100. The improvement rate (%) of ΔE*ab(D65) is expressed as {(increase rate of ΔE*ab(D65) for each reference example - increase rate of ΔE*ab(D65) for each example) / increase rate of ΔE*ab(D65) for each reference example} x 100. The improvement rate (%) of ΔE*ab(D65) of the comparative example is expressed as {(increase rate of ΔE*ab(D65) of the reference example - increase rate of ΔE*abD65) of the comparative example) / increase rate of ΔE*ab(D65) of the reference example} × 100. Each reference example is a composition obtained by omitting salicylic acid from the composition of each example or comparative example, and in Tables 2 and 3, it refers to the composition to the left of the respective example or comparative example.

[0083] In the example composition containing 30% by mass of propylene glycol, the brightness-improving effect of salicylic acid was observed. On the other hand, in the composition containing 60% by mass of propylene glycol, this effect was not observed. The same was true for compositions containing propanediol. Furthermore, the same was true when bases other than propylene glycols were used. In the composition containing 30% by mass of propylene glycol, the brightness-improving effect of salicylic acid was observed. On the other hand, in the composition containing 60% by mass, this effect was not observed. The same was true for propanediol. Furthermore, the same results were observed when using other bases besides propylene glycols.

[0084] Furthermore, these effects were observed in the compositions of the examples in which a mixture of 1,3-propanediol and propylene glycol was used, and the effects were also confirmed in the compositions of the examples in which the total content of 1,3-propanediol and propylene glycol was 15% by mass. The effects were also confirmed when polyethylene glycol was used as the base or when the amount of salicylic acid was reduced.

[0085] The compositions of the Examples all had reduced coloring, a more subdued overall color, and high transparency when compared with the Standard and Comparative Examples.

[0086] [Test Example 2: Friction Improvement Verification Test] (static friction coefficient) Artificial leather (Suprare PBZ13001 (Idemitsu Technofine Co., Ltd.)) was attached to the moving table of the friction tester, and 1 mL of each composition was spread on the artificial leather so that it was thoroughly distributed directly under the contact. Next, a 50 g weight was attached to the measurement unit. The contact was attached to the measurement unit, and measurements were performed 1000 times per second for 20 seconds. The average value of the friction coefficient obtained from the measurement results at the start of movement was calculated and used as the friction coefficient (μk) of the formulation. Note that a "tactile contact imitating a fingerprint pattern" was used as the contact of the friction tester (Tribomaster TL201Ts, manufactured by Trinity Labs). Measurement conditions: Weight: 50g, Measurement time: 20 seconds, Movement distance: 10cm, Movement speed: 5mm / s, Value measured every 1msec.

[0087] [Table 4] [Table 5] [Table 6]

[0088] Here, the friction improvement rate (%) of each Example or Comparative Example is expressed as {(friction coefficient of each Reference Example - friction coefficient of each Example or Comparative Example) / friction coefficient of each Reference Example} × 100. Each Reference Example is a composition obtained by removing salicylic acid from the composition of each Example or Comparative Example, and refers to the composition to the left of the respective Example or Comparative Example in Tables 4 to 6.

[0089] Adding salicylic acid to 30% by mass of 1,3-propanediol reduced friction. At 60% by mass of 1,3-propanediol, no improvement was observed, and friction increased. Furthermore, the coefficient of friction of Example 3-1 was lower than that of any of the reference examples or comparative examples, confirming the smoothness of the composition when first applied to the skin.

[0090] Furthermore, these effects were observed in the compositions of the examples in which a mixture of 1,3-propanediol and propylene glycol was used, and the effects were also confirmed in the compositions of the examples in which the total content of 1,3-propanediol and propylene glycol was 15% by mass. The effects were also confirmed when polyethylene glycol was used as the base or when the amount of salicylic acid was reduced.

[0091] (dynamic friction coefficient) The artificial leather was attached to the moving table of the friction tester, and 1 mL of the test formulation was spread on the artificial leather so that it was thoroughly distributed directly under the contact. Next, a 50 g weight was attached to the measurement unit. The contact was attached to the measurement unit, and measurements were performed 1,000 times per second for 20 seconds. The average value of the friction coefficient obtained from the measurement results 5 to 15 seconds after the start of measurement was calculated and used as the friction coefficient (μk) of the formulation. Note that a "tactile contact imitating a fingerprint pattern" was used as the contact of the friction tester (Tribomaster TL201Ts, manufactured by Trinity Labs). Measurement conditions: Weight: 50g, Measurement time: 20 seconds, Movement distance: 10cm, Movement speed: 5mm / s, Value measured every 1msec.

[0092] [Table 7]

[0093] Here, the friction improvement rate (%) of each Example or Comparative Example is expressed as {(friction coefficient of each Reference Example - friction coefficient of each Example or Comparative Example) / friction coefficient of each Reference Example} × 100. Each Reference Example is a composition obtained by removing salicylic acid from the composition of each Example or Comparative Example, and refers to the composition to the left of the corresponding Example or Comparative Example in Table 7.

[0094] Adding salicylic acid to 30% by mass of 1,3-propanediol reduced friction. At 60% by mass of 1,3-propanediol, no improvement was observed, and friction increased. Furthermore, the coefficient of friction of Example 4-1 was lower than that of any of the reference examples or comparative examples, confirming the smoothness of the composition when applied to the skin.

[0095] [Prescription example] Formulation examples are shown in the following Tables 8 and 9. All formulation examples are beauty serums, and the contents in the formulation examples are all in mass %.

[0096] [Table 8]

[0097] [Table 9]

Claims

1. A composition for external use on skin, comprising: (A) 0.5 to 5% by mass of at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid; (B) 0.001 to 5% by mass of at least one selected from the group consisting of salicylic acid and salts of salicylic acid; (C) 1 to 50% by mass of a diol having 3 carbon atoms; and (D) 0.1 to 30% by mass of water.

2. The external skin composition according to claim 1, further comprising 1 to 20% by mass of (E) a lower alcohol.

3. The composition for external use on skin according to claim 1 or 2, which has a pH of 2 to 5.

4. A method for inhibiting discoloration of a topical skin composition containing (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, by blending 0.5 to 5 mass% of (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, 0.001 to 5 mass% of (B) at least one selected from the group consisting of salicylic acid and salts of salicylic acid, 1 to 50 mass% of (C) a diol having 3 carbon atoms, and 0.1 to 30 mass% of (D) water.

5. A discoloration inhibitor for a topical skin composition containing (A) 0.5 to 5 mass% of at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, and containing (B) 0.001 to 5 mass% of at least one selected from the group consisting of salicylic acid and salts of salicylic acid, 1 to 50 mass% of a diol having 3 carbon atoms, and (D) 0.1 to 30 mass% of water.

6. A method for improving the feel when used in a composition for external use on skin, which contains 0.5 to 5 mass% of at least one selected from the group consisting of (A) ascorbic acid and salts of ascorbic acid, by using 0.5 to 5 mass% of at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, (B) 0.001 to 5 mass% of at least one selected from the group consisting of salicylic acid and salts of salicylic acid, (C) 1 to 50 mass% of a diol having 3 carbon atoms, and (D) 0.1 to 30 mass% of water.

7. A usability improver for a topical skin composition containing 0.5 to 5 mass% of (A) at least one selected from the group consisting of ascorbic acid and salts of ascorbic acid, and containing 0.001 to 5 mass% of (B) at least one selected from the group consisting of salicylic acid and salts of salicylic acid, 1 to 50 mass% of (C) a diol having 3 carbon atoms, and 0.1 to 30 mass% of (D) water.

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