Skin composition and skin treatment method

Abstract

The present invention provides a skin composition that can suppress the unpleasant odor of the composition itself, which is derived from the incorporation of cysteine, a cysteine ​​derivative, or a salt thereof, and a skin treatment method using the skin composition. [Solution] The skin composition of the present invention is characterized by containing (A) cysteine, a cysteine ​​derivative, or a salt thereof and (B) a zinc salt or a copper salt. Also, the skin treatment method of the present invention is characterized by applying the skin composition of the present invention to the skin.

Description

[Technical Field]

[0001] The present invention relates to skin compositions and methods for treating skin. [Background technology]

[0002] Conventionally, in the fields of cosmetics and pharmaceuticals, various components having various functions have been developed and used, but for example, although functionally effective, there are also components that cannot be used or whose usage is limited due to reasons such as the emission of an unpleasant odor. For this reason, technologies for suppressing the unpleasant odor caused by components used in the above fields are also being investigated.

[0003] For example, Patent Document 1 proposes a composition containing at least one selected from the group consisting of pearl protein extract, yeast extract, and hydrolyzed collagen, and an extract of a plant of the genus Winged Bean in the family Fabaceae, and characterized by its use as a cosmetic or food or beverage. It has been shown that the composition of Patent Document 1 sufficiently suppresses the unpleasant odors characteristic of pearl protein extract, yeast extract, or hydrolyzed collagen, despite containing these ingredients. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-53063 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, cysteine ​​or a salt thereof is known to have antioxidant properties and to promote metabolism in the skin and the like, and is used as an active ingredient in compositions such as orally ingested pharmaceuticals.

[0006] Furthermore, by incorporating cysteine, a cysteine ​​derivative, or a salt thereof into preparations such as cosmetics that are applied directly to the skin by application, it is expected that the effect of these compounds in promoting skin metabolism can be more effectively achieved. However, compositions containing cysteine, a cysteine ​​derivative, or a salt thereof emit a very strong, unpleasant odor, making them difficult to use for such applications.

[0007] Therefore, when cysteine, a cysteine ​​derivative, or a salt thereof is incorporated as an active ingredient into a composition to be applied to the skin, it is necessary to develop a technology for suppressing the unpleasant odor caused by these ingredients.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a skin composition that can suppress the unpleasant odor of the composition itself that results from the incorporation of cysteine, a cysteine ​​derivative, or a salt thereof, and a skin treatment method using the skin composition. [Means for solving the problem]

[0009] The skin composition of the present invention is characterized by comprising (A) cysteine, a cysteine ​​derivative, or a salt thereof and (B) a zinc salt or a copper salt.

[0010] The method for treating skin of the present invention is characterized by applying the skin composition of the present invention to the skin. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a skin composition that can suppress the unpleasant odor of the composition itself that results from the incorporation of cysteine, a cysteine ​​derivative, or a salt thereof, and a skin treatment method using the skin composition. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the present invention will be described based on an embodiment of the present invention (hereinafter referred to as the present embodiment).

[0013] <Skin composition> The skin composition of this embodiment contains (A) cysteine, a cysteine ​​derivative, or a salt thereof (hereinafter sometimes referred to as component (A)) and (B) a zinc salt or copper salt (hereinafter sometimes referred to as component (B)). The skin composition of this embodiment can suppress the unpleasant odor of (A) cysteine, a cysteine ​​derivative, or a salt thereof by (B) the zinc salt or copper salt, and therefore can suppress the unpleasant odor of the composition itself resulting from the incorporation of component (A) (for example, the unpleasant odor felt upon opening a container containing the skin composition).

[0014] Furthermore, the skin composition of the present embodiment can suppress not only the unpleasant odor of the composition itself as described above, but also the unpleasant odor that occurs when a skin composition containing component (A) is used on the skin (for example, the unpleasant odor that is felt when the skin composition is taken out of a container containing the skin composition and applied to the skin).

[0015] (A) cysteine, a cysteine ​​derivative, or a salt thereof The skin composition of this embodiment contains one or more components (A). Component (A) may be one or more selected from cysteine ​​or a salt thereof, and a cysteine ​​derivative or a salt thereof. Examples of the salt include alkali metal salts, inorganic acid salts (e.g., hydrochlorides, sulfates, phosphates), and organic acid salts.

[0016] Examples of the cysteine ​​or a salt thereof include L-cysteine, DL-cysteine, D-cysteine, and L-cysteine ​​hydrochloride. Examples of the cysteine ​​salt include cysteine ​​hydrochloride, sulfate, and phosphate. The cysteine ​​derivative or a salt thereof may be a compound containing one or more selected from acetylcysteine ​​or a salt thereof, and cysteamine or a salt thereof. Examples of the acetylcysteine ​​or a salt thereof include N-acetyl-L-cysteine. Examples of the cysteamine or a salt thereof include cysteamine and cysteamine hydrochloride.

[0017] In view of being able to further suppress the unpleasant odor of the composition itself resulting from the incorporation of component (A), the skin composition of this embodiment preferably contains one or more components selected from cysteine ​​or a salt thereof, and acetylcysteine ​​or a salt thereof as component (A).

[0018] The amount of component (A) in the skin composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, from the viewpoint of further enhancing the metabolic effect of component (A) when the skin composition of this embodiment is applied to the skin. There is no particular upper limit on the amount of component (A) in the skin composition of this embodiment, and it may be set taking into account the amounts of other components to be incorporated into the skin composition. The amount of component (A) in the skin composition of this embodiment may be, for example, 3% by mass or less, or 2.5% by mass or less.

[0019] (B) Zinc salt or copper salt The skin composition of this embodiment contains one or more components (B). As a component for suppressing the unpleasant odor caused by component (A), for example, a divalent metal salt other than a zinc salt or a copper salt can be used, but zinc salts or copper salts are effective as component (B).

[0020] As will be described later, the skin composition of this embodiment typically uses water as a solvent, and therefore, from the viewpoint of effectively suppressing the unpleasant odor caused by component (A), it is preferable to use a water-soluble zinc salt or copper salt as component (B). Note that "water-soluble zinc salt or copper salt" refers to a zinc salt or copper salt that dissolves in an amount of 0.1 g or more in 100 g of water at 25°C.

[0021] As the zinc salt of component (B), various zinc salts of organic acids and zinc salts of inorganic acids can be used. More specifically, examples include water-soluble zinc salts such as zinc salts of organic acids such as zinc glycinate, zinc gluconate, zinc pyrrolidonecarboxylate, zinc lactate, zinc citrate, zinc ascorbate, and zinc salicylate; and zinc salts of inorganic acids such as zinc sulfate. Other zinc salts of component (B) include, for example, zinc cocoalkyl sulfate, zinc coceth sulfate, and zinc lauroyl aspartate. While component (A) is used as a reducing agent that cleaves cystine bonds in hair proteins in permanent wave agents or hair straighteners, the present inventors have confirmed that, for example, in compositions containing component (A) together with zinc glycinate, the function of component (A) as a reducing agent that cleaves cystine bonds in hair proteins is lost or reduced.

[0022] As the copper salt of component (B), various copper salts of organic acids and copper salts of inorganic acids can be used. More specific examples include water-soluble copper salts such as copper salts of organic acids such as copper gluconate, copper aspartate, and copper pyrrolidonecarboxylate.

[0023] The skin composition of this embodiment may be an embodiment in which cysteine, a cysteine ​​derivative, or a salt thereof (e.g., L-cysteine, N-acetyl-L-cysteine) is blended as component (A), and a water-soluble zinc salt or copper salt is blended as component (B); more specifically, an embodiment in which a zinc salt of an organic acid (e.g., zinc glycinate, zinc pyrrolidonecarboxylate, zinc gluconate), a zinc salt of an inorganic acid (e.g., zinc sulfate), or a copper salt of an organic acid (e.g., copper gluconate) is blended.

[0024] For component (B), one or more of the various zinc salts and copper salts exemplified above can be used, but from the viewpoint of further improving the stability of the skin composition over time (for example, the stability of the color of the composition over time), it is preferable to use a zinc salt. Furthermore, among zinc salts, it is more preferable to use a zinc salt of an organic acid, and it is particularly preferable to use zinc glycine or zinc pyrrolidonecarboxylate, because this has a better effect of suppressing unpleasant odors caused by the incorporation of component (A) (the unpleasant odor of the composition itself resulting from the incorporation of component (A) and the unpleasant odor when a skin composition containing component (A) is used on the skin).

[0025] The blending amount of the component (B) in the skin composition of this embodiment is, for example, from 0.01% by mass to 20% by mass.

[0026] The amount of component (B) in the skin composition of this embodiment is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, from the viewpoint of further suppressing the unpleasant odor of the skin composition itself resulting from the addition of component (A). Also, the amount of component (B) in the skin composition of this embodiment is preferably 15% by mass or less, from the viewpoint of suppressing stickiness when applied to the skin.

[0027] When the skin composition of this embodiment uses, for example, a water-soluble zinc salt or copper salt as component (B), the ratio b / a of the amount a (% by mass) of component (A) to the amount b (% by mass) of component (B) is preferably 0.5 or more, more preferably 0.7 or more, even more preferably 1 or more, even more preferably 1.2 or more, particularly preferably 1.5 or more, and most preferably 1.7 or more, from the viewpoint of further suppressing the unpleasant odor of the skin composition itself resulting from the incorporation of component (A). When the skin composition of this embodiment uses a zinc salt of an organic acid or a copper salt of an organic acid, which are particularly highly functional, as component (B), by setting b / a to 0.7 or more, preferably 1 or more, more preferably 1.2 or more, even more preferably 1.4 or more, particularly preferably 1.5 or more, and most preferably 1.7 or more, the unpleasant odor can be more effectively suppressed from the time a container containing the skin composition is opened until the skin composition is removed from the container and applied to the skin, for example by applying it to the skin.

[0028] The upper limit of b / a in the skin composition of this embodiment is not particularly limited, but may be, for example, such that the above blend amounts of component (A) and component (B) are satisfied. For example, b / a in the skin composition of this embodiment is 2000 or less. From the viewpoint of reducing stickiness when applied to the skin, b / a in the skin composition of this embodiment is preferably 30 or less, and more preferably 5 or less.

[0029] solvent The skin composition of this embodiment preferably contains water as a solvent for component (A). The amount of water in the hair wash composition of this embodiment is not particularly limited and may be appropriately set, but is, for example, 50% by mass or more and 99% by mass or less.

[0030] pH and pH adjusters The skin composition of the present embodiment has a pH of, for example, 5.0 or more and 8.5 or less at 25° C. Hereinafter, in this specification, the pH at 25° C. will be simply referred to as "pH." The pH can be measured by using a known pH meter for the skin composition of the present embodiment adjusted to 25° C.

[0031] The skin composition of this embodiment contains both component (A) and component (B), which can suppress the unpleasant odor of the skin composition itself resulting from the incorporation of component (A). However, precipitation may occur in the skin composition. In such cases, adjusting the pH of the skin composition of this embodiment may reduce the precipitation of component (A). For example, in a skin composition containing zinc glycine as component (A), the pH is preferably 6.8 or higher, more preferably 7.0 or higher, even more preferably 7.2 or higher, and even more preferably 7.4 or higher, in order to reduce the precipitation.

[0032] The pH of the skin composition of the present embodiment is preferably 8.5 or less, more preferably 8.0 or less, from the viewpoint of reducing the risk of skin irritation.

[0033] The skin composition of this embodiment may be blended with a pH adjuster to adjust the pH. Examples of the pH adjuster include acids and alkalis. Examples of the acids include organic acids (e.g., citric acid, lactic acid, glycolic acid, malic acid, succinic acid) and inorganic acids (e.g., phosphoric acid). Examples of the alkalis include inorganic alkalis (e.g., potassium hydroxide, sodium hydroxide, ammonia) and organic alkalis (e.g., aminoethylpropanol, arginine, triethanolamine).

[0034] The amount of pH adjuster blended in the skin composition of this embodiment may be an amount that allows the pH of the skin composition to be, for example, the above-mentioned value.

[0035] Compatible ingredients In addition to the above-mentioned components, the skin composition of this embodiment can also contain, as needed, various components that are incorporated into compositions such as cosmetics that are applied to the skin. Examples of components that can be incorporated include surfactants (cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants), oils (ester oils, fats and oils, hydrocarbons, waxes, silicones, etc.), fatty acids, higher alcohols, lower alcohols, polyhydric alcohols, proteins, amino acids, sugars, polymeric compounds, animal and plant extracts, substances derived from microorganisms, inorganic compounds, fragrances, preservatives, sequestering agents, and ultraviolet absorbers.

[0036] others The formulation of the skin composition of this embodiment is not particularly limited, and specific formulations of the skin composition of this embodiment include, for example, liquid, cream, gel, paste, ointment, solid, foam, mist, powder, aerosol, and patch.

[0037] The skin composition of the present embodiment is applied to the skin. The skin composition of the present embodiment may be used on the scalp or on skin other than the scalp.

[0038] The skin composition of the present embodiment may be used, for example, for antioxidation or whitening of the skin. The skin composition of the present embodiment may be, for example, a skin composition for antioxidation or whitening of the skin, and may be in the form of a skin composition product in which the fact that the composition is used for antioxidation or whitening of the skin or the effect of antioxidation or whitening of the skin is indicated on the package, pamphlet, instruction manual, or other explanatory materials.

[0039] When applying the skin composition of this embodiment to the skin (i.e., treating the skin using the skin composition of this embodiment), an appropriate amount may be applied to the skin by coating, spraying, applying, etc., in a manner appropriate for the formulation of the skin composition.

[0040] The skin composition of this embodiment can be in the form of a product such as a skin lotion (scalp lotion, lotion for skin other than the scalp), a skin emulsion (scalp emulsion, emulsion for skin other than the scalp), a skin cream (scalp cream, cream for skin other than the scalp), a pack, or a mask.

[0041] <Skin treatment method> The skin treatment method of this embodiment involves applying the above-described skin composition of this embodiment to the skin. As the skin treatment method of this embodiment, any known method for using a skin composition may be employed, in addition to using the skin composition of this embodiment. Therefore, for example, a method of applying the above-described skin composition of this embodiment to the skin may be employed. [Example]

[0042] The present invention will be described in detail below based on examples. However, the following examples do not limit the present invention. In the following Tables 1 to 4, the blend amount of each component is shown in % so that the total skin composition is 100%, but all of the % is mass %. Furthermore, in these tables, the % indication is omitted and only the numerical value indicating the blend amount is shown.

[0043] Examples 1 to 16 and Comparative Examples 1 to 4 The skin compositions of Examples 1 to 16 and Comparative Examples 1 to 4 were prepared by mixing L-cysteine, N-acetyl-L-cysteine, cysteamine, zinc glycine, zinc pyrrolidonecarboxylate, zinc gluconate, zinc sulfate, copper gluconate, calcium gluconate, potassium hydroxide, citric acid, and water in a conventional manner to obtain the compositions shown in Tables 1 to 4.

[0044] The odor of the skin compositions of the Examples and Comparative Examples was evaluated using the following method. 50 g of each of the skin compositions of the Examples and Comparative Examples was placed in a 50 mL transparent screw-cap bottle and the lid was closed. The odor was then detected when the lid of the screw-cap bottle was opened, and when approximately 0.5 g of the skin composition was taken out of the screw-cap bottle and spread onto the skin of the palm of the hand. Each odor was evaluated by ranking it according to the following criteria. The evaluation was performed by a single person who regularly evaluates skin cosmetics.

[0045] (Odor evaluation criteria) ×: Unpleasant odor (unpleasant odor not suppressed). △: An unpleasant odor is felt, but the unpleasant odor is suppressed compared to products rated ×. ○: There is a slight odor, but it is not unpleasant. ◎: No unpleasant odor (even the odor that is felt in products rated ○).

[0046] In addition, each skin composition was placed in a screw-cap bottle with a lid closed, and the appearance was evaluated by visually observing the condition at room temperature one day after preparation.

[0047] The results of each of the above evaluations are shown in Tables 1 to 4. The "potassium hydroxide" or "citric acid" column in Tables 1 to 4 indicates the amount of potassium hydroxide or citric acid that results in the pH (25°C) of the skin composition shown in the pH column for each Example or Comparative Example. The "total of 100" in the "water" column in Tables 1 to 4 means that the amount of water added to the total amount of each component other than water blended into the skin composition equals 100%. In Tables 1 to 4, the evaluation results of the odor upon opening the screw-cap bottle lid are shown in the "Odor at bottle opening" column, and the evaluation results of the odor upon application to skin are shown in the "Odor upon application to skin" column. Furthermore, in the "Appearance" column in Table 1, "transparent" means that the skin composition in the screw-cap bottle remained transparent, "very slightly cloudy" means that the skin composition in the screw-cap bottle was almost transparent but had a very slight white cloudiness, "cloudy" means that precipitates had formed, causing the skin composition to become opaque with a white cloudiness, and "cloudy" means that precipitates had formed, causing the skin composition to become opaque with a black cloudiness.

[0048] [Table 1]

[0049] [Table 2]

[0050] [Table 3]

[0051] [Table 4]

[0052] As shown in Table 1, the skin composition of Comparative Example 1, which did not contain component (B), gave off an unpleasant odor due to component (A), L-cysteine, both when the lid of the screw-cap bottle containing the composition was opened and when the composition was applied to the skin. However, the skin compositions of Examples 1 to 9, which contained component (A), L-cysteine, as well as component (B), zinc glycine, were able to suppress the unpleasant odor due to L-cysteine.

[0053] The skin composition of Example 1, in which b / a was 0.5, was able to suppress the unpleasant odor when the lid of the screw-cap bottle containing the composition was opened, but was unable to sufficiently suppress the unpleasant odor when applied to the skin. However, the skin composition of Example 2, in which b / a was 1, was able to suppress the unpleasant odor when applied to the skin to a certain extent, and the skin composition of Example 3, in which b / a was 1.5, was able to almost completely suppress the unpleasant odor when applied to the skin. The skin compositions of Examples 4 to 7, in which b / a was 2, were able to better suppress the unpleasant odor when the lid of the screw-cap bottle containing the composition was opened. Furthermore, the skin compositions of Examples 8 and 9, in which b / a was 3, were able to better suppress the unpleasant odor when applied to the skin, in addition to the unpleasant odor when the lid of the screw-cap bottle containing the composition was opened.

[0054] Furthermore, the skin composition of Example 6, which had a relatively low pH, became cloudy due to precipitation of L-cysteine. However, the skin compositions of Examples 4 and 5, which had the same composition as the skin composition of Example 6 except that the pH was increased by adjusting the amount of potassium hydroxide, and the skin composition of Example 8, which had the same composition as the skin composition of Example 9 except that the pH was increased by adjusting the amount of potassium hydroxide, were able to suppress precipitation of L-cysteine ​​and become transparent or only slightly cloudy.

[0055] Furthermore, the skin compositions of Example 10 and Comparative Example 2 shown in Table 2 are examples in which N-acetyl-L-cysteine ​​was used as component (A). However, the skin composition of Comparative Example 2, which did not contain component (B), gave off an unpleasant odor due to N-acetyl-L-cysteine ​​both when the lid of the screw-cap bottle in which it was stored was opened and when it was applied to the skin. In contrast, the skin composition of Example 10, which also contained zinc glycine as component (B), was able to effectively suppress these unpleasant odors.

[0056] Furthermore, the skin compositions of Examples 11 to 15 shown in Table 3 were examples using zinc salts or copper salts other than zinc glycinate. However, the skin compositions of Examples 11 to 13 and 15, which used zinc salts or copper salts of organic acids, were able to suppress the unpleasant odor caused by L-cysteine ​​both when the lid of the bottle containing the composition was opened and when applied to the skin. The skin composition of Example 14, which used a zinc salt of an inorganic acid (zinc sulfate), was also able to suppress the unpleasant odor caused by L-cysteine ​​both when the lid of the bottle containing the composition was opened and when applied to the skin. However, the level of suppression was inferior to that of the skin compositions of Examples 11 to 13 and 15, and cloudiness due to L-cysteine ​​precipitation was also observed. On the other hand, the skin composition of Comparative Example 3, which used calcium gluconate instead of component (B), exhibited an unpleasant odor caused by component (A), L-cysteine, both when the lid of the bottle containing the composition was opened and when applied to the skin, as shown in Table 3.

[0057] The skin composition of Example 15, which used a copper salt (copper gluconate) as component (B), discolored and turned black immediately after preparation, and had poor stability over time. However, the skin compositions of Examples 1 to 14, which used a zinc salt, did not show such a change and had good stability over time.

[0058] Furthermore, the skin compositions of Example 16 and Comparative Example 4 shown in Table 4 are examples in which cysteamine was used as component (A). However, the skin composition of Comparative Example 4, which did not contain component (B), gave off an unpleasant odor due to cysteamine both when the lid of the screw-cap bottle in which it was stored was opened and when it was applied to the skin. In contrast, the skin composition of Example 16, which also contained zinc glycine as component (B), was able to effectively suppress these unpleasant odors.

[0059] Furthermore, as can be seen from Tables 1, 2, and 4, the skin composition of Example 5, which contained L-cysteine ​​as component (A), and the skin composition of Example 10, which contained N-acetyl-L-cysteine ​​as component (A), were superior in suppressing unpleasant odors when the lids of the screw-cap bottles in which they were contained were opened, compared to the skin composition of Example 16, which used cysteamine as component (A).

Claims

1. (A) cysteine, a cysteine ​​derivative, or a salt thereof; (B) Zinc salt or copper salt A skin composition containing the above.

2. 2. The skin composition according to claim 1, wherein (B) is a water-soluble zinc salt or a water-soluble copper salt.

3. 3. The skin composition according to claim 1, wherein the ratio of the amount a (% by mass) of (A) to the amount b (% by mass) of (B): b / a is 0.5 or more.

4. 3. The skin composition according to claim 1, wherein (B) is zinc glycine, zinc gluconate, zinc pyrrolidonecarboxylate, or copper gluconate.

5. 5. The skin composition according to claim 4, wherein zinc glycine is blended as said (B).

6. 6. The composition for skin according to claim 5, which has a pH of 6.8 or higher.

7. A method for treating skin, comprising applying the skin composition according to claim 1 or 2 to the skin.

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