JPH09221406A - Skin cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a skin cosmetic excellent in aging preventing effects such as chopped skin improving effect, keratin improving effect, turn over rate increasing effect, developing and providing beautiful skin effect by using specific two kinds of compounds. SOLUTION: This skin cosmetic is obtained by combining one or more selected from mevalonic acid and mevalonolactone with one or more of amino acids. Readily obtainable R(-)-mevalonic acid is preferable as the mevalonic acid. Mevalonolactone is a compound to be readily converted to mevalonic acid by hydrolysis. Serine, threonine, n-methylserine, γ-aminobutyric acid, etc., is preferable as the amino acids. The amount of the mevalonic acid blended in the skin cosmetic is 0.001-10wt.%, especially about 0.01-2.0wt.% and that of the amino acid is 0.001-3.0wt.%, especially about 0.01-2.0wt.%. The amount of the amino acid blended is preferably 0.1-10 times as much as mevalonic acid or mevalonolactone.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a skin cosmetic, and more specifically, it exhibits and imparts an excellent anti-aging effect (rough skin improving effect, keratin improving effect, effect of increasing turnover speed) and beautiful skin effect. Especially, it relates to excellent skin cosmetics.

[0002]

2. Description of the Related Art Aged skin becomes rough and dry without smoothness, and keratinocyte exfoliation is observed. Aged skin has a slow turnover speed, and it is said that the turnover speed of the skin increases when the antiaging effect is developed and imparted to the skin. Heretofore, various cosmetics have been proposed which give an appropriate moist feeling and flexibility to the skin surface, and for example, JP-A-4-99707 proposes a skin cosmetic containing R-(-) mevalonic acid. However, although these skin cosmetics act on the epidermis of the skin tissue, they rarely act on the dermis, which is the tissue under the epidermis, and thus have sufficient effects for preventing skin aging as described above. There was nothing.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a skin cosmetic which exhibits and imparts an anti-aging effect (rough skin improving effect, keratin improving effect, effect of accelerating turnover speed) and beautiful skin effect. Especially.

[0004]

Means for Solving the Problems The above object is achieved by a skin cosmetic composition containing (a) one or more kinds selected from mevalonic acid and mevalonic acid lactone, and (b) one kind of amino acid.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The mevalonic acid used as the component (a) in the present invention is also referred to as pyroclastic acid (molecular formula: C ₆ H ₁₂ O ₄ ), which is true pyroclastic bacteria (Lactobacillus) mixed in sake.
lulus homeochichi and L. et al. hetero
chichi), and lactic acid bacteria (L. a.
Cidophilus), a substance found as a growth-promoting factor, and is used as a biosynthesis precursor for isoprenoid compounds such as sterols, or as a raw material for chemically or enzymatically synthesizing various optically active substances. Mevalonic acid has two isomers [R (-)-mevalonic acid, S (+)
-Mevalonic acid], and naturally-occurring R (-)-
Although any of mevalonic acid can be used in the present invention, R (−)-mevalonic acid, which is easily available, is preferable.
R (-)-mevalonic acid is described, for example, in JP-A-63-216.
484, JP-A-63-216485, JP-A-63-
It can be produced by the microbial fermentation method described in JP-A-216486 and JP-A-63-216487. Alternatively, a racemate (mixture of isomers) can be produced by a chemical synthesis method, and each isomer can be separated. Further, mevalonic acid lactone (molecular formula: C ₆ H ₁₀ O ₃ ) which is a derivative of mevalonic acid used as the component (a) in the present invention is
It is a compound having the property of easily changing to mevalonic acid by hydrolysis.

On the other hand, the amino acids used as the component (b) in the present invention include, for example, glycine, serine, valine, lysine, cystine, cysteine, alanine, leucine, isoleucine, glutamine, glutamic acid, tryptophan, arginine, asparagine, aspartic acid. , Threonine, methionine, phenylalanine, histidine,
Proline, n-methylserine, laminin, taurine, γ
-Aminobutyric acid, amino acid mixture obtained by hydrolyzing protein of animal or plant origin, other than amino acid mixture obtained by microbial fermentation, yeast cells, seaweed, amino acid mixture extracted from plant seeds, etc. Can be mentioned.
Further, it may be obtained by a chemical synthesis method. By using serine, threonine, n-methylserine, or γ-aminobutyric acid among these amino acids, it is possible to obtain a dermocosmetic which is more effective in use.

It is known that the above amino acids exist as important constituents of natural moisturizing factors in the skin, and play an important role in retaining water in the stratum corneum of the skin. These effects act synergistically with the effects of mevalonic acid and mevalonic acid lactone to develop and impart favorable anti-aging effect (effect of improving rough skin, effect of improving keratin, effect of accelerating turnover speed), and beautiful skin effect. is there.

In the skin cosmetic of the present invention, the preferred blending amount of one or more of mevalonic acid and mevalonic acid lactone of component (a) is preferably 0.001 to 10% by weight, based on the total amount of the skin cosmetic. (Hereinafter abbreviated as wt%.)
And particularly preferably 0.01 to 2.0 wt%. The blending amount of one or more amino acids is preferably 0.0
01 to 3.0 wt%, and particularly preferably 0.01
~ 2.0 wt%. Furthermore, it is desirable to mix the amino acid in an amount (weight) of 0.1 to 10 times that of mevalonic acid or mevalonic acid lactone.

The dosage form of the skin cosmetic of the present invention is not particularly limited, and may be cream, emulsion, lotion,
Conventional skin cosmetic formulations such as ointments and powders can be applied. The skin cosmetics of the present invention appropriately contain, as other components, an emulsifier, an oily substance, a moisturizer, a thickener, a fragrance, an antiseptic, an antioxidant, a colorant and the like within a range to achieve the object of the present invention. You can

[0010]

The present invention will be described below in detail based on examples and comparative examples. In the Examples, (1) the method for measuring the turnover speed of the stratum corneum, (2) the method for measuring the effect of improving rough skin, (3) the method for measuring the effect of improving stratum corneum, and (4) the sensory test are as follows. .

(1) Method for measuring turnover rate of stratum corneum 5 wt% of dansyl chloride as a fluorescent dye in white petrolatum
% Ointment was prepared and occluded and applied to the skin of the forearm of 20 subjects for 24 hours, and dansyl chloride was osmotically bonded to the stratum corneum. Thereafter, the test sample was applied to the same site twice a day (morning and evening), and the fluorescence of dansyl chloride was examined every day.
The number of days until the fluorescence disappeared was defined as the skin stratum corneum turnover speed. The measurement results were shown as an average of the number of days for each subject. The normal skin stratum corneum turnover is 1
4-16 days, but extends around 18 days in aged skin. On the other hand, when the anti-aging effect appears, 12
It is shortened to around days.

(2) Method for measuring the effect of improving rough skin The effect of continuous application for 4 weeks was investigated for 20 middle-aged and elderly subjects who had rough skin on their lower legs. That is, a test sample is applied to the left lower leg test site of the subject twice a day (morning and evening),
The skin condition before and after the test was evaluated according to the criteria shown in Table 1 below. The lower leg on the right side was used as a control without applying the test sample.

[0013]

[Table 1]

Then, the judgment results of the test site before and after the test and the control site are compared, and when the skin dryness is improved by two stages or more (for example: + →-, ++ → ±), it is "effective" and improved by one stage When the result is "slightly valid", when there is no change, it is considered "invalid". The test results are shown by the number of subjects who were “effective” and “somewhat effective”.

(3) Method for measuring the effect of improving keratin (increasing the anti-peeling property of keratinocytes) Scotch tape (Nichiban Mending Tape) is adhered to the skin of the test area before and after the start of and the end of the rough skin improvement measurement test. When this is peeled off, the state of keratinocytes attached to the tape is examined in detail by a scanning electron microscope,
The stratum corneum exfoliating property was classified according to the criteria shown in Table 2 below, and the effect of improving the keratin was determined.

[0016]

[Table 2]

The judgment is "effective" when the difference between the evaluation point of the test site and that of the control site after continuous application for 4 weeks is 2 or more, "effective", 1 or more is "slightly effective", and 0 is 0. "Invalid" The test results are shown by the number of subjects who were “effective” and “somewhat effective”.

(4) Sensory test (Beautiful skin effect) Female subjects who complain of rough skin, fine wrinkles, dry skin (35-35)
Test sample twice a day (morning, evening) for 20 persons 3
The coating was applied for 1 month, and the effect after 1, 2 and 3 months was evaluated.
In the test results, for each item of skin wettability, smoothness, and elasticity, the respondents answered that "skin was moistened", "skin became smooth", and "skin became taut" Indicated by the number of people.

Examples 1 to 4 and Comparative Examples 1 to 7 (skin cream) Table 4 shows one or more kinds selected from the mevalonic acid and mevalonic acid lactone of the component (a) and one kind selected from the amino acids of the component (b). Each of the skin creams was prepared by blending as described in 1 above and having the composition of Table 3, and the above-mentioned various experiments were carried out.

(1) Composition

[Table 3]

(2) Preparation Method The raw materials of group (A) in Table 3 above were melted at 70 ° C., mixed with the raw material (B), and then heated to 78 ° C. Then this is 7
Preliminary emulsification was carried out by gradually adding to the raw material (C) heated to 5 ° C. with stirring. Then, homogenize the mixture completely and emulsify it. After cooling to 50 ° C, add (D) to 30 ° C.
Cooled down. In addition, R (-) compounded as the component (a)
-Mevalonic acid lactone is R (-) in skin cream
-It is considered that it exists in equilibrium with mevalonic acid.

(3) Properties Tables 4 and 5 show the results of various tests performed on each skin cream.

[0023]

[Table 4]

[0024]

[Table 5]

As shown in Tables 4 and 5, mevalonic acid, mevalonic acid lactone (b), which is the component (a) of Comparative Examples 1 to 7.
The skin cream containing no amino acid as a component or a skin cream containing only one amino acid cannot achieve sufficient effects in various properties. However, (a) mevalonic acid, mevalonic acid lactone and (b) component of Examples 1 to 4 of the present invention. The skin cream combined with the amino acid described above has a remarkable effect in improving rough skin, improving keratin, and increasing turnover speed, that is, a remarkable effect in preventing skin aging. A sensory test was conducted two months after application. The wettability, smoothness, elasticity, and imparting effect were obtained.

Example 5, Comparative Examples 8 to 10 (oil-based cream) Each oil-based cream having the composition shown in Table 6 below was prepared and various tests were carried out.

(1) Composition

[Table 6]

(2) The components shown in Table 6 above were stirred and uniformly dissolved to prepare an oily cream.

(3) Characteristics Table 7 shows the results of a sensory test conducted on each oily cream.

[0030]

[Table 7]

As is clear from Table 7 above, the oil-based cream of Example 5 exhibited a skin aging-preventing action two months after application, and a good skin-beautifying effect was obtained.

Example 6, Comparative Examples 11 to 13 (skin lotion) Each skin lotion was prepared according to the composition shown in Table 6 below, and various tests were carried out. The yeast autolysate used as the component (b) of the present invention is a powder containing an amino acid obtained by autolyzing baker's yeast, followed by clarification filtration, and freeze-drying.

(1) Composition

[Table 8]

(2) Preparation Method The ingredients in Table 8 above were stirred and uniformly dissolved to prepare a skin lotion. (3) Characteristics The skin lotion of Example 6 showed excellent skin beautiful effects and skin aging prevention effects (rough skin improvement effect, keratin improvement effect, and effect of accelerating turnover speed) as compared with Comparative Examples 11 to 13.

Example 7 (Skin Cream) A skin cream having the composition shown in Table 9 below was prepared.

[Table 9]

(2) Preparation method The components (A) and (B) shown in Table 9 were uniformly heated and dissolved to bring the temperature to 80 ° C. Then, after injecting and emulsifying the component (B) into the component (A) A, the mixture is stirred at 30 ° C.
Cooled down.

Example 8 (makeup base) A makeup base having the composition shown in Table 10 below was prepared. (1) Composition

[Table 10]

(2) Preparation method The components (A) A and (B) shown in Table 10 were uniformly heated and dissolved to bring the temperature to 80 ° C. Next, the component (A) was injected and emulsified while stirring the component B with a homomixer, and then cooled to 30 ° C.

Example 9 (Skin milk) A skin milk having the composition shown in Table 11 below was prepared. (1) Composition

[Table 11]

(2) Preparation method The components (A) and (B) shown in Table 11 were uniformly heated and dissolved to bring the temperature to 80 ° C. Then, after injecting and emulsifying the component (B) in the component (A), the mixture is stirred at 30 ° C.
Cooled down.

The above Examples 7 to 9 showed excellent effects of preventing skin aging (effect of improving rough skin, effect of improving keratin, effect of accelerating turnover speed) and beautiful skin effect.

[0042]

As described above, the present invention provides a useful skin cosmetic excellent in skin aging prevention effect (rough skin improvement effect, keratin improvement effect, turnover speed increasing effect) and skin beautiful effect. Is clear.

Claims (1)

[Claims] 1. A skin cosmetic comprising (a) one or more kinds selected from mevalonic acid and a mevalonic acid lactone, and (b) one or more kinds of amino acids.