JPH0632713A - Skin external preparation - Google Patents

Abstract

PURPOSE:To obtain a skin external preparation remarkably improved in stability of vitamin A and/or its fatty acid ester. CONSTITUTION:This skin external preparation is obtained by blending vitamin A and/or its fatty acid ester with (A) one or two or more oil-soluble antioxidants selected from the group consisting of butylhydroxytoluene, butylhydroxyanisole, alpha-, beta-, gamma-and delta-tocopherols, nordihydroguaiaretic acid, propyl gallate, vitamin C ester of a fatty acid and sorbic acid, (B) one or two or more of ethylenediaminetetraacetates and (C) one or two or more of benzophenone- based compounds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external preparation for skin in which the stability of vitamin A and / or its fatty acid ester is remarkably improved.

[0002]

2. Description of the Related Art Vitamin A and / or its fatty acid ester is known to be an effective component for the prevention and treatment of cutaneous keratoses and the prevention and recovery of skin aging.

However, vitamin A and / or its fatty acid ester is structurally extremely unstable, and light,
Since various isomerizations, decompositions, polymerizations, etc. are easily caused by air, heat, metal ions, etc., it has been difficult to stably compound them in the skin external preparation.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies in view of such circumstances, the present inventors have found that (A) butylhydroxytoluene (hereinafter abbreviated as BHT) and butylhydroxy together with vitamin A and / or its fatty acid ester. A type of oil-soluble antioxidant selected from the group consisting of anisole (hereinafter abbreviated as BHA), α, β, γ, δ-tocopherol, nordihydroguaiaretin, propyl gallate, vitamin C fatty acid ester, and sorbic acid. Alternatively, the stability of vitamin A and / or its fatty acid ester is remarkably improved by blending two or more kinds with (B) one or more kinds of ethylenediaminetetraacetic acid salt and (C) one or more kinds of benzophenone compounds. The inventors have found that they are improved and have completed the present invention.

[0005]

That is, the gist of the present invention is to provide vitamin A and / or a fatty acid ester thereof, and
(A) Butylhydroxytoluene (hereinafter abbreviated as BHT), butylhydroxyanisole (hereinafter abbreviated as BHA), α, β, γ, δ-tocopherol, nordihydroguaiaretin, propyl gallate, and vitamin C fatty acid. One or more oil-soluble antioxidants selected from the group consisting of esters and sorbic acid, (B) one or more ethylenediaminetetraacetic acid salts, (C) one or more benzophenone compounds, It exists in the external preparation for skin characterized by being compounded.

The structure of the present invention will be described in detail below.

Vitamin A and / or used in the present invention
Examples of the fatty acid ester thereof include vitamin A (also known as retinol), vitamin A acetate (also known as retinol acetate), and vitamin A palmitate (also known as retinol palmitate), all trans type or 13-cis type. Is preferable, and a mixture thereof may be used. Further included are fatty oils obtained from fresh aquatic animals liver and pyloric appendix, and concentrates thereof.

There is no particular limitation on the amount to be added to the skin external preparation according to the present invention, but considering the effect of vitamin A on the skin, it is 0.0001% by weight or more, and the effect of vitamin A is strongly appealed. In order to
It is 1% by weight or more. The upper limit of the compounding ratio is preferably 10% by weight in view of the property as an external preparation for skin.

Oil-soluble antioxidants to be added to the external preparation for skin according to the present invention include BHT, BHA, α, β, γ,
Examples include δ-tocopherols, nordihydroguaiaretin, propyl gallate, vitamin C fatty acid ester, and sorbic acid.

The amount applied to the present invention is 0.001
It is preferably at least wt%, more preferably at least 0.01 wt%. In order to exert the effects of the invention for a longer period, 0.03% by weight is preferable. The upper limit of blending differs depending on the dosage form of the external preparation for skin and cannot be limited because it can be arbitrarily blended, but it is preferably 10% by weight in view of the properties as an external preparation for skin.

Examples of the ethylenediaminetetraacetic acid salt used in the present invention include inorganic alkali salts such as sodium salt and potassium salt, and organic alkali salts such as ethanolamines such as mono-, di-, tri- and tetra-salts. It is illustrated.

The amount blended in the present invention is 0.00
It is 1% by weight or more, and the upper limit of blending is not particularly limited. However, when blended in an extremely large amount, the effect of the present invention is not impaired, but the quality as a skin external preparation can be maintained due to precipitation of crystals and the like. Disappear. It is preferably 1% by weight or less.

The benzophenone-based compounds used in the present invention include 2,4-dihydroxybenzophenone (hereinafter benzophenone-1), 2,2 ', 4,4'-tetrahydroxybenzophenone (hereinafter benzophenone-2),
2-hydroxy-4-methoxybenzophenone (hereinafter benzophenone-3), 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (hereinafter benzophenone-)
4), 2-hydroxy-4-methoxybenzophenone-
Sodium 5-sulfonate (hereinafter benzophenone-
5), 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (hereinafter benzophenone-6), 2-hydroxy-5-chlorobenzophenone (hereinafter benzophenone-7), 2,2'-dihydroxy-4-methoxybenzophenone (Hereinafter benzophenone-8), 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-
5,5'-Disodium disodium salt (hereinafter benzophenone-9), 2-hydroxy-4-methoxy-4'methylbenzophenone (hereinafter benzophenone-10), 2-
Examples thereof include hydroxy-4-octyloxybenzophenone (hereinafter benzophenone-12).

The content of the external preparation for skin of the present invention is 0.001% by weight or more, and the upper limit of the content is not particularly limited, but the effect of the present invention is impaired when the content is extremely large. Although it is not a substance, the quality as an external preparation for skin cannot be maintained due to the precipitation of crystals. Preferably 1
It is 0% by weight or less.

In the external preparation for skin of the present invention, in addition to the above-mentioned essential components, other components usually used in cosmetics and quasi drugs, such as moisturizers, surfactants, preservatives, water, alcohols, thickeners, Oils, chemicals, chelating agents, fragrances, coloring agents, ultraviolet absorbers and the like can be added, if necessary, within a range that does not impair the effects of the present invention.

[0016]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

[0017]

[Table 1]

In Examples 1 and 2, the stability of retinol acetate was improved as compared with Comparative Example, which is an effect according to the present invention.

Production methods of Examples 1 and 2 and Comparative Examples 1 and 2
Temperature test method BHT, tocopherol, benzophenone, and octyl methoxycinnamate were completely dissolved in each oil component at 60 ° C., and then purified water was added with dissolved edetate, ethyl alcohol, and dipropylene glycol, and 40 ° C.
Cool down. Then completely dissolve the retinol acetate,
It is sealed in a brown glass sample tube, wrapped with aluminum foil, completely protected from light, and stored in a constant temperature bath at 40 ° C.

Quantitative Method for Retinol Acetate The Japanese Pharmacopoeia (11th revision) Vitamin A Quantitative Method According to the first method, quantitative determination was carried out by an absorbance measuring method using isopropanol.

[0021]

[Table 2]

In Examples 3 and 4, the stability of retinol was improved as compared with Comparative Example, which is an effect according to the present invention.

The manufacturing method of Examples 3 and 4 and Comparative Examples 3 and 4
Temperature test method BHT, tocopherol and benzophenone-2 are completely dissolved in each oil component and a surfactant at 70 ° C, and then retinol acetate is completely dissolved immediately before emulsification to obtain an oil phase. Glycerin, propylene glycol, carboxyvinyl polymer, caustic potash, trisodium edetate and benzophenone-5 were completely dissolved in purified water and the oil phase was added to the aqueous phase heated to 70 ° C. and emulsified by a homomixer type emulsifier.
Next, a heat exchanger is used to cool the mixture to 30 ° C. to obtain an emulsion. The emulsion is filled in a glass bottle with a metal coat,
Seal and store in a constant temperature bath at 40 ° C.

Retinol Quantitative Method It was measured by an absorbance measuring method at 325 nm using ethanol. Samples were prepared by removing retinol from the examples and comparative examples, and the absorption at 325 nm was measured and corrected as the absorbance of the base. (Absorbance at 325 nm of samples of Examples and Comparative Examples)-(Absorbance of withdrawn product) = Absorbance of retinol Absorption maximum 325 nm, E (1%, 1)
cm) = 1835.

Example 5 Lotion (wt%) oleyl alcohol 0.002 benzophenone-12 0.001 α-tocopherol 0.001 retinol acetate 0.0001 POE (50) oleyl ether 0.7 lactic acid 0.1 sodium lactate 0 9.9 Ethanol 8 Glycerin 2 Methylparaben 0.2 Trisodium edetate 0.01 Purified water Amount based on 100

Example 6 Oil Essence (% by Weight) 2-Ethylhexanoic Acid Triglyceride 30 Octyldodecanol 20 Squalane 12 BHT 1 α-Tocopherol 9 Retinol Acetate 8 Retinol Palmitate 2 Dipropylene Glycol 12.899 Ethyl Alcohol 5 Benzophenone-8 0.1 Disodium edetate 0.001

Example 7 Cream (wt%) Squalane 15 2-Ethylhexanoic Acid Triglyceride 8 Isopropylmyristate 7 BHT 0.05 BHA 0.01 α-Tocopherol 0.01 Retinol 0.3 Vaseline 2 Butylparaben 0.1 Propyl Paraben 0.1 Oleic acid monoglyceride 3 Diglycerin diisostearate 2 PEG400 Dioleate 1 Glycerin 10 Dipropylene glycol 5 Disodium edetate 0.01 Benzophenone-6 0.1 Benzophenone-4 0.03 Triethanolamine 0.04 Purification Amount of water as 100

Example 8 Oil Essence (wt%) Isopropyl myristate 10 Octyldodecanol 20 Squalane 30 BHT 1 α-Tocopherol 9 Retinol acetate 1 Dibutylphthalate 9 Ethyl alcohol 9.999 Benzophenone-12 7 Benzophenone-6 3 Sodium edetate 0.001

Example 9 Oil Gel (wt%) 2-Ethylhexanoic Acid Triglyceride 60 POE (20) Octyldodecyl Ether 16 Retinol 0.1 Benzophenone-12 0.1 Glycerin 16 Benzophenone-5 0.05 Trisodium Edetate 0 .02 BHA 0.01 BHT 0.01 Purified water Amount based on 100

The skin external preparations of Examples 5 to 9 were excellent in stability of vitamin A and / or its fatty acid ester in daily use.

[0031]

In the external preparation for skin of the present invention, (A) butylhydroxytoluene (hereinafter abbreviated as BHT), butylhydroxyanisole (hereinafter abbreviated as BHA),
One or more oil-soluble antioxidants selected from the group consisting of α, β, γ, δ-tocopherol, nordihydroguaiaretin, propyl gallate, vitamin C fatty acid ester and sorbic acid, (B) ethylenediamine tetra Stability of vitamin A and / or its fatty acid ester can be significantly improved by blending one or more acetates and one or more benzophenone compounds (C).

Claims (1)

[Claims] 1. A (A) butylhydroxytoluene (hereinafter abbreviated as BHT), butylhydroxyanisole (hereinafter abbreviated as BHA), α, together with one or more kinds of vitamin A and / or its fatty acid ester. β,
γ, δ-tocopherol, nordihydroguaiaretin,
One or more oil-soluble antioxidants selected from the group consisting of propyl gallate, vitamin C fatty acid ester, and sorbic acid, (B) one or more ethylenediaminetetraacetic acid salts, and (C) benzophenone compounds An external preparation for skin, characterized by containing one or more kinds.