JP2005023040A - Dermatological plaster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dermatological plaster having good gelation of a crosslinked polymer even when vitamin C is blended and excellent in adhesiveness and shape-retaining property to the skin. <P>SOLUTION: The dermatological plaster comprises a crosslinked polymer gel containing a water-soluble vitamin C derivative or its salt and a water-soluble polymer and the plaster is obtained by blending alumina magnesium hydroxide into the gel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００４３】
［外皮用貼付剤の評価１］
実施例及び比較例の外皮用貼付剤について５０℃で３日間保存し、ゲル化、粘着力及び外観について評価を行った。ゲルの解離は、ゲル化したサンプルを８０℃で７日間保存し，ゲルの状態を観察した。但し、粘着力、外観及びゲルの解離については、ゲル化したサンプルのみ評価を行った。結果を表２に示す。
（Ａ）ゲル化の判定基準；貼付後の残存ゲルの有無で評価した。
−：全くなし、＋：残膏あり
（Ｂ）粘着力の判定基準；ヒト皮膚に貼付した時の粘着力で評価した。
−：良好、＋：悪い
（Ｃ）外観の判定基準；ゲルの色調を目視により評価した。
−：変化なし、±：わずかな褐変あり、＋：かなりの褐変あり
（Ｄ）ゲルの解離の判定基準；
−：問題なし、
＋：ゲル架橋が壊れ、貼付後に残膏がある状態。
【００４４】
【表２】

【００４５】
［外皮用貼付剤の評価２］
（１）ゲルのｐＨ
ゲル５ｇと精製水５０ｍＬをホモジナイズした溶液のｐＨをｐＨメーターで測定した。
【００４６】
（２）Ｌ−アスコルビン酸リン酸マグネシウムの安定性
サンプルを４０℃、７５％ＲＨで保存し、０箇月、３箇月及び６箇月の各々の含量を測定した。Ｌ−アスコルビン酸リン酸マグネシウムの含量は、ホモジナイザーにて抽出し，下記の条件により、内標準法によりＨＰＬＣ法で測定した。内標準物質はマレイン酸を使用して測定した。結果を表３に示す。
【００４７】
（３）操作条件
検出器：紫外吸光光度計（測定波長：２５４ｎｍ）
分離管：内径４．６ｍｍ、長さ１５０ｍｍのステンレス管に、オクタデシル基で修飾した５μｍのシリカゲルを充填する。
移動相：２．８ｍＭ ｎ−ヘキシルアミン、０．１ｍＭエデト酸二ナトリウム及び２％メタノールを含むように調製した０．０８Ｍ酢酸−酢酸ナトリウム緩衝液（ｐＨ５．０）
流速：０．７ｍＬ／分
【００４８】
【表３】

【００４９】
表２及び表３より、本発明の外皮用貼付剤は、ゲル化、皮膚への粘着性及び保形性が良好で、且つゲルの色調の変化がなく、しかも安定性に優れることが認められた。
【００５０】
【発明の効果】
水酸化アルミナマグネシウムを架橋剤として使用する本発明の外皮用貼付剤は、メタケイ酸アルミン酸マグネシウム、ジヒドロキシアルミニウムアミノアセテート、合成ケイ酸アルミニウム、合成ヒドロタルサイト等、数多くある他の架橋剤の単独又は複数を組み合わせて使用した場合に比較して、水溶性高分子が強度に架橋されたゲルが形成でき、しかも長期保存した場合においてもゲルの解離がなく、ゲルの色調にも変化がなく、安定で、且つ粘着力及び保形性が良好であることから、色素沈着防止（美白・美肌）等のビタミンＣの効果を安定して発揮し得る貼付剤として極めて有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a skin patch containing a water-soluble vitamin C derivative or a salt thereof, which contains magnesium hydroxide alumina as a water-soluble polymer crosslinking agent.
[0002]
[Prior art]
In skin patches such as conventional hydrous cataplasms, in order to obtain good water retention and shape retention, polyvalent metal derivatives of amino acids and polyvalent metal salts of amino acids are usually used as cross-linking agents for polymer substances. Etc. are performed (for example, refer patent document 1). Further, a cataplasm containing a magnesium hydroxide alumina as a cross-linking agent is known in order to further satisfy points such as adhesiveness to the skin, water retention, shape retention, and drug release (see, for example, Patent Document 2). .
[0003]
On the other hand, vitamin C or derivatives thereof and salts thereof (vitamin Cs) are known to have an effect of preventing abnormal deposition of pigment due to suppression of skin melanin production. It is blended in cosmetics such as creams and packs. Among these, as the pack, a sheet-like impregnating pack that is easy to handle and saves the labor of taking the chemical solution is commercially available. However, the impregnating pack only impregnates the non-woven fabric with the chemical solution. During use, the chemical solution flows to the outside and stains hands, etc., the impregnating pack falls off, and the work of cleaning and removing after use is troublesome. There was a problem such as. Therefore, an adhesive patch with shape retention has been desired.
[0004]
However, when vitamin C is added to the adhesive patch base, a stable cross-linked polymer gel is formed because no cross-linking is formed between the water-soluble polymers due to the interaction between vitamin C and the metal cross-linking agent. There was a problem that it was difficult to mold as a patch. On the other hand, a cataplasm that solves the above-mentioned problems has been devised by blending two kinds of magnesium aluminate metasilicate, dry aluminum hydroxide gel and aluminum chloride as a crosslinking agent (for example, patents). However, it is not always satisfactory in terms of tackiness and long-term stability.
[0005]
[Patent Document 1]
JP-A-60-260513 [Patent Document 2]
Japanese Patent Publication No. 4-50291 [Patent Document 3]
Japanese Patent Laid-Open No. 2001-64175
[Problems to be solved by the invention]
An object of the present invention is to provide a skin patch that is excellent in gelation of a water-soluble polymer and excellent in adhesiveness and shape retention to the skin even when vitamin C is blended.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention contain a water-soluble vitamin C derivative or a salt thereof among vitamin Cs, and when magnesium alumina hydroxide is used as a crosslinking agent, The present invention has been completed by finding that a water-soluble polymer gelation is excellent, that it is possible to obtain a stable vitamin C-containing skin patch that does not change the appearance of the gel and that has excellent adhesiveness and shape retention to the skin. did.
[0008]
That is, the present invention relates to a skin patch comprising a crosslinked polymer gel containing a water-soluble vitamin C derivative or a salt thereof and a water-soluble polymer, wherein the skin is formed by blending magnesium hydroxide in the gel. An adhesive patch is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The skin patch of the present invention contains a water-soluble vitamin C derivative or a salt thereof, and uses magnesium alumina hydroxide as a cross-linking agent for a water-soluble polymer. When vitamin Cs are blended in a cross-linked polymer gel of a skin patch such as a patch, it is difficult to form a cross-link between water-soluble polymers due to the interaction between vitamin C and the cross-linking agent. By using alumina magnesium oxide as a crosslinking agent, crosslinking is suitably formed between the polymers. That is, the water-soluble polymer blended with magnesium hydroxide alumina as a crosslinking agent used a magnesium aluminate metasilicate, dihydroxyaluminum aminoacetate, synthetic aluminum silicate, synthetic hydrotalcite, or the like as a crosslinking agent. Compared to the case, in the presence of vitamin C, it can be strongly crosslinked to form a gel having excellent shape retention.
[0010]
For example, “sanalmine” (Kyowa Chemical Industry Co., Ltd.) can be used as the alumina magnesium hydroxide. Here, “sanalmin” is more preferably “sanalmin S”, which is a spray-dried product, rather than a normal belt conveyor dry product. By using this, cross-linking is fast, and a small amount is excellent in adhesiveness and shape retention. Can be obtained.
[0011]
The blending amount of magnesium alumina hydroxide is preferably 0.05 to 5.0% by weight, more preferably 0.1 to 4.0% by weight, based on the total amount of the crosslinked polymer gel. 2 to 3.0% by weight is particularly preferable.
[0012]
As the water-soluble polymer, those described in JP-B-4-50291 or JP-A-2001-64175 can be suitably used. Specifically, polyacrylate (sodium polyacrylate, potassium polyacrylate, etc.), polyacrylic acid, polyvinyl alcohol, methyl vinyl ether / maleic anhydride copolymer, alginate such as sodium alginate, carboxyvinyl polymer, Examples thereof include natural polymers such as gelatin, gum arabic, glucomannan, xanthan gum and gum tragacanth, carboxymethylcellulose salts such as hydroxypropylcellulose, carboxymethylcellulose and sodium carboxymethylcellulose, celluloses such as methylcellulose and ethylcellulose, and polyethylene oxide.
[0013]
Of these polymers, polyacrylates are preferred, and of these, completely neutralized products are more preferred. The polyacrylate may be used singly, but another polymer such as hydroxypropylcellulose, polyvinyl alcohol, sodium alginate, sodium carboxymethylcellulose, carboxyvinyl polymer, etc. may be added to the polyacrylate. These can be used in combination. For example, by combining carboxyvinyl polymer with sodium polyacrylate, the shape retention is better and the adhesiveness can be improved.
Here, in terms of adhesiveness, it is possible to adjust to a suitable adhesive strength at each application site by the JIS Z0237 ball tack measurement method.
[0014]
The content of the water-soluble polymer varies depending on the type of polymer to be selected, but is preferably 1 to 30% by weight, more preferably 4 to 20% by weight, based on the total amount of the crosslinked polymer gel. In addition, when using together a polyacrylate and another polymer, it is preferable to make content of a polyacrylate 0.5 to 29.5 weight%, Furthermore, 3.5 to 19.5 weight% More preferably. Further, the total content of other polymers is preferably 0.01 to 10.0% by weight, more preferably 0.1 to 5.0% by weight. By adjusting the content of the polymer in this way, it is possible to produce a skin patch having good shape retention and good adhesion.
[0015]
Examples of the water-soluble vitamin C derivative include L-ascorbic acid phosphoric acid derivatives such as L-ascorbic acid phosphoric acid and L-ascorbic acid aminopropyl phosphate; L-ascorbic acid sulfuric acid derivatives; L-ascorbic acid glucoside, etc. And a sugar derivative of L-ascorbic acid. And as these salts, sodium salt, calcium salt, magnesium salt, zinc salt etc. are mentioned, Sodium salt and magnesium salt are preferred. As the water-soluble vitamin C derivative or a salt thereof, an L-ascorbic acid phosphoric acid derivative or a salt thereof is preferable, and L-ascorbic acid magnesium phosphate is particularly preferable.
Such water-soluble vitamin C derivatives or salts thereof may be used in combination of two or more.
[0016]
The content of the water-soluble vitamin C derivative or a salt thereof is preferably 0.01 to 20% by weight, more preferably 0.1 to 15% by weight, and still more preferably 0 to the total amount of the crosslinked polymer gel. .2 to 10.0% by weight.
[0017]
When the skin patch of the present invention is used, a water-soluble vitamin C derivative or a salt thereof is efficiently percutaneously absorbed, and vitamin C has a skin melanin production inhibitory action, a melanocyte growth inhibitory action, an antioxidant action (reactive oxygen) Removal action), collagen synthesis promoting action, sebum secretion inhibiting action, UV and cell damage protecting action, skin repairing action, skin metabolism promoting action, tissue building action, etc., for example, whitening / skinning effect, light Aging and skin cancer prevention and treatment effects, spots, buckwheat and aza prevention and treatment effects, skin firmness effect, wrinkle prevention and treatment effects, scar and acne scar repair promotion effects, skin oxidation suppression effect , Prevention / improvement effect of acne, skin repair promotion effect against burns / abrasion, prevention / treatment effect of skin inflammation, cholesterol lowering effect, The effect of preventing emissions materials, thrombotic effect of reducing vein or the like can be obtained.
[0018]
In the skin patch of the present invention, an appropriate amount of water is used for dispersing / dissolving active ingredients, water-soluble polymers, humectants, crosslinking agents, preservatives and the like. In addition, it can be expected to take away heat of vaporization due to volatilization of water, suppress the burning and inflammation of the face, and at the same time give a pleasant refreshing feeling. The water content is preferably 20 to 80% by weight, more preferably 40 to 65% by weight, based on the total amount of the crosslinked polymer gel.
[0019]
The crosslinked polymer gel used for the skin patch of the present invention, which is formulated with magnesium hydroxide alumina as a crosslinking agent, can maintain good shape retention and adhesiveness in a wide acidic to alkaline pH range. However, the pH of the crosslinked polymer gel is preferably 7.0 to 9.5 from the viewpoint of stability of the water-soluble vitamin C derivative or salt thereof under long-term storage and irritation to the skin. If the pH is lower than 7.0, there is a problem in the stability of the drug. If the pH is higher than 9.5, there is irritation to the skin, so the pH of the crosslinked polymer gel is 7.0 to 9.5. Preferably there is.
[0020]
In addition to the water-soluble vitamin C derivative or a salt thereof, the skin patch of the present invention can contain active ingredients such as skin-beautifying ingredients and refreshing / sedative ingredients. Beautiful skin ingredients include yeast; herbal extracts such as chamomile, lavender, melissa and rose; grain extracts such as fermented rice extract and fermented rice bran extract; licorice extract, iris root extract, rose extract, burdock extract, majorana extract, beech extract, western tang Plant extracts such as flower grass extract, aloe extract, loofah extract, yukinoshita extract, fennel extract, fire spine extract, green tea extract and carrot extract; natural ingredients such as spa ingredients, negative ion ingredients and minerals; vitamins such as retinol and tocopherols; Seaweed extract; Ceramide; Herbal medicine; Oligosaccharide; Protein; Allantoin; Collagen; Amadorin; Sodium hyaluronate; Urea; Glycerin; Sorbitol; Propylene glycol; Butylene glycol; Martinol; Ntaekisu; hydroquinone derivative can be appropriately compounded. As refreshing and soothing ingredients, L-menthol, DL-menthol, DL-camphor, eucalyptus oil, peppermint oil, isopulegol, 3-L-menthoxypropane-1,2-diol, L-menthyl-3-hydroxybutyrate, etc. Can be appropriately blended.
In addition, analgesic / anti-inflammatory agents, anti-inflammatory agents, blood circulation promoters and the like used in pharmaceuticals can be appropriately blended.
[0021]
The skin patch of the present invention may further contain a moisturizing agent used in ordinary cataplasms and packs. Examples of the humectant include polyhydric alcohols such as concentrated glycerin, glycerin, sorbitol liquid, propylene glycol, 1,3-butylene glycol, and polyethylene glycol. Of these, concentrated glycerin, glycerin or sorbitol solution is preferred. The content of the polyhydric alcohol is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, based on the total amount of the crosslinked polymer gel. By blending these polyhydric alcohols in an appropriate range, shape retention and adhesiveness can be maintained for a long time.
[0022]
The skin patch of the present invention may further contain various additives used for ordinary cataplasms, packs and the like. Additives include alcohols such as ethanol and isopropanol; antioxidants such as sodium bisulfite and tocopherol acetate; absorption enhancers such as menthol; carboxyvinyl polymer, sodium alginate, carrageenan, sodium carboxymethylcellulose, hydroxypropylcellulose, etc. Thickeners; preservatives such as methylparaben, propylparaben, butylparaben, phenoxyethanol; surfactants such as sorbitan sesquioleate and hydrogenated castor oil; oils such as jojoba oil, eucalyptus oil, castor oil; pH such as sodium hydroxide Adjustment agents; fragrances; pigments and the like. Further, the blending amount is not particularly limited and can be appropriately adjusted according to the purpose of use.
[0023]
In addition, chelating agents such as ethylenediaminetetraacetic acid and sodium edetate, dicarboxylic acids such as tartaric acid, and amines such as triethanolamine affect the formation of cross-links, and the cross-linked polymer gel tends to dissociate even when cross-linked. Therefore, it is desirable that the blending amount is small or not blended.
[0024]
The skin patch of the present invention may further contain inorganic substances such as kaolin, bentonite and titanium oxide. Of the inorganic substances, kaolin is preferably used.
[0025]
Examples of the form of the skin patch of the present invention include poultices, cosmetic packs, gel sheets and the like, from the viewpoint of ease of use and maintenance of the effects of water-soluble vitamin C derivatives or salts thereof and other active ingredients. Packing agents are preferred.
[0026]
The outer skin patch of the present invention is produced, for example, by applying a polymer gel prepared by uniformly kneading the above components to a paste and spreading it on a support according to a conventional method. be able to. Here, as the support, nonwoven fabric or woven fabric such as synthetic fiber and absorbent cotton; paper; synthetic resin film such as polyethylene, polypropylene, polyurethane, vinyl chloride, polyester, polyamide, rayon; and the synthetic resin film and nonwoven fabric or woven fabric Examples include a laminate of cloth. When using the support body of a laminated body, a water vapor transmission rate can be adjusted by selecting the material of a synthetic resin film, or giving a pore. It is also possible to produce a patch with reduced skin irritation by increasing moisture permeability, or to produce a highly absorbent patch using the ODT effect by reducing moisture permeability. The support may be either stretchable or non-stretchable, but preferably exhibits a suitable stretchability depending on the application site. After spreading on the support, release paper may be bonded to the gel surface to protect the gel. Moreover, it is good also as a shaping | molding pack agent only of bridge | crosslinking polymer gel by extending a gel to a synthetic resin film without using a support body, or shape | molding with a type | mold.
[0027]
【Example】
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
[0028]
[Example 1]
Component (3), component (4), component (5) and component (7) shown in Table 1 below are mixed well, and component (13) and component (20) are dispersed in component (8). And mixed well (mixed solution a1). Furthermore, the component (10) was added to the mixed solution a1 and mixed well (mixed solution b1). Separately, a solution obtained by pretreating component (1), component (21), component (25), and component (27) with component (32) was added to mixed solution b1 and mixed well to obtain a gel. Subsequently, the obtained gel was spread on a base fabric made of polyester fiber with a liner so as to be 1000 g / m ² , cut, and placed in an aluminum bag, thereby producing the skin patch 1 of the present invention.
[0029]
[Example 2]
The skin patch 2 of the present invention was produced in the same manner as in Example 1 except that the component (7) was removed and the component (9) was added instead of the component (8).
[0030]
[Example 3]
Component (3), Component (4), Component (5), Component (6) and Component (7) are mixed well, and here Component (13), Component (18), (20) and Component (23) are mixed. The liquid dispersed in component (8) and component (12) was added and mixed well (mixed solution a3). Furthermore, the component (10) was added to the mixed solution a3 and mixed well (mixed solution b3). Separately, component (1), component (24), and component (27) pretreated with component (32) are added to mixed solution b3 and mixed well to obtain a gel. An outer skin patch 3 was produced.
[0031]
[Example 4]
Component (3), component (4), component (5) and component (6) are mixed well, and a liquid in which component (13) and component (20) are dispersed in component (9) and component (11) is mixed here. In addition, the mixture was mixed well (mixed solution a4). Furthermore, component (10) was added to the mixed solution a4 and mixed well (mixed solution b4). Separately, component (1), component (21), component (22), and component (27) were pretreated with component (32) and added to mixture b4 and mixed well to obtain a gel, similar to Example 1. Thus, the skin patch 4 of the present invention was produced.
[0032]
[Examples 5 and 6]
Outer patches 5 and 6 of the present invention were produced in the same manner as in Example 1 except that the gel obtained on the nonwoven fabric side of the base fabric obtained by laminating a nonwoven fabric made of polyester fibers and a polyurethane film was spread.
[0033]
[Comparative Example 1]
A skin patch 1-1 was produced in the same manner as in Example 1 except that the component (14) was added instead of the component (13).
[0034]
[Comparative Example 2]
A skin patch 1-2 was produced in the same manner as in Example 1 except that the component (15) was blended in place of the component (13).
[0035]
[Comparative Example 3]
A skin patch 1-3 was produced in the same manner as in Example 1 except that the component (16) was added instead of the component (13).
[0036]
[Comparative Example 4]
A skin patch 1-4 was produced in the same manner as in Example 1 except that the component (17) was added instead of the component (13).
[0037]
[Comparative Example 5]
A skin patch 1-5 was produced in the same manner as in Example 1 except that the component (18) was added instead of the component (13).
[0038]
[Comparative Example 6]
Component (3), component (4), component (13), component (20) and component (30) were dispersed and mixed with component (9), component (11) and component (29) (mixed solution a6). The component (10) was added to the mixed solution a6 and mixed well (mixed solution b6). Separately, component (2), component (24), and component (27) pretreated with component (32) are added to the mixed solution b6 and mixed well to obtain a gel. No. 1 skin patch 1-6 was produced.
[0039]
[Comparative Example 7]
Component (3), Component (4), Component (13), Component (26), Component (28), Component (30) and Component (31) were dispersed and mixed with Component (9) and Component (11) ( Mixture a7). The component (10) was added to the mixed solution a7 and mixed well (mixed solution b7). Separately, component (2), component (24), component (25), and component (27) were pretreated with component (32) and added to mixture b7 and mixed well to obtain a gel, similar to Example 1. Thus, a skin patch 1-7 of the present invention was produced.
[0040]
[Comparative Example 8]
Component (3), component (4), component (18), component (19), component (20) and component (30) were dispersed and mixed with component (9) and component (29) (mixed solution a8). The component (10) was added to the mixed liquid a8 and mixed well (mixed liquid b8). Separately, a solution obtained by pretreating component (1), component (24), and component (27) with component (32) is added to the mixed solution b8 and mixed well to obtain a gel. No. 1 skin patch 1-8 was produced.
[0041]
[Comparative Example 9]
Component (3), component (4), component (16), component (18), component (20) and component (30) were dispersed and mixed with component (9) and component (11) (mixed solution a9). The component (10) was added to the mixed solution a9 and mixed well (mixed solution b9). Separately, component (1) component (24) and component (27) pretreated with component (32) were added to mixture 9 and mixed well to obtain a gel. Outer skin patch 1-9 was produced.
[0042]
[Table 1]

[0043]
[Evaluation of skin patch 1]
The skin patches of Examples and Comparative Examples were stored at 50 ° C. for 3 days and evaluated for gelation, adhesive strength and appearance. For dissociation of the gel, the gelled sample was stored at 80 ° C. for 7 days, and the state of the gel was observed. However, only the gelled samples were evaluated for adhesive strength, appearance, and gel dissociation. The results are shown in Table 2.
(A) Judgment criteria for gelation: Evaluated by the presence or absence of residual gel after application.
-: None at all, +: With plaster (B) Judgment criteria for adhesive strength; evaluated by adhesive strength when applied to human skin.
-: Good, +: Bad (C) Judgment criteria for appearance; The color tone of the gel was visually evaluated.
-: No change, ±: Slight browning, +: Substantial browning (D) Criterion for gel dissociation;
-: No problem,
+: The gel cross-linking is broken, and there is a residual plaster after application.
[0044]
[Table 2]

[0045]
[Evaluation of skin patch 2]
(1) pH of the gel
The pH of a solution obtained by homogenizing 5 g of gel and 50 mL of purified water was measured with a pH meter.
[0046]
(2) Stability samples of L-ascorbic acid magnesium phosphate were stored at 40 ° C. and 75% RH, and the contents of 0 month, 3 months, and 6 months were measured. The content of magnesium phosphate L-ascorbate was extracted with a homogenizer and measured by the HPLC method according to the internal standard method under the following conditions. The internal standard was measured using maleic acid. The results are shown in Table 3.
[0047]
(3) Operation condition detector: ultraviolet absorption photometer (measurement wavelength: 254 nm)
Separation tube: A stainless steel tube having an inner diameter of 4.6 mm and a length of 150 mm is filled with 5 μm silica gel modified with an octadecyl group.
Mobile phase: 0.08 M acetic acid-sodium acetate buffer (pH 5.0) prepared to contain 2.8 mM n-hexylamine, 0.1 mM disodium edetate and 2% methanol.
Flow rate: 0.7 mL / min
[Table 3]

[0049]
From Tables 2 and 3, it is recognized that the skin patch of the present invention has good gelation, adhesion to the skin and shape retention, no change in gel color tone, and excellent stability. It was.
[0050]
【The invention's effect】
The outer skin patch of the present invention using magnesium aluminate hydroxide as a cross-linking agent can be used alone or in combination with many other cross-linking agents such as magnesium aluminate metasilicate, dihydroxyaluminum aminoacetate, synthetic aluminum silicate, synthetic hydrotalcite, etc. Compared to the case of using multiple combinations, a gel in which water-soluble polymers are strongly cross-linked can be formed, and even when stored for a long period of time, the gel does not dissociate and the color of the gel does not change and is stable. In addition, since the adhesive strength and shape retention are good, it is extremely useful as a patch capable of stably exhibiting the effects of vitamin C, such as prevention of pigmentation (whitening and skin beautification).

Claims (6)

A skin patch comprising a crosslinked polymer gel containing a water-soluble vitamin C derivative or a salt thereof and a water-soluble polymer, wherein the gel is blended with magnesium alumina hydroxide in the gel. The skin patch according to claim 1, wherein the water-soluble vitamin C derivative or a salt thereof is an L-ascorbic acid derivative or a salt thereof. The skin patch according to claim 1 or 2, wherein the water-soluble vitamin C derivative or a salt thereof is magnesium L-ascorbate phosphate. The skin patch according to any one of claims 1 to 3, wherein magnesium hydroxide is mixed in an amount of 0.05 to 5.0% by weight of the total amount of the gel. The skin patch according to any one of claims 1 to 4, wherein the water-soluble polymer contains a polyacrylate. The patch for outer skin according to any one of claims 1 to 5, wherein the cross-linked polymer gel has a pH of 7.0 to 9.5.