JPH06145038A - Skin cosmetic - Google Patents

Abstract

PURPOSE:To obtain a useful skin cosmetic, excellent in beatifying and whitening effects and accelerating effects on the turnover rate of horny layers without skin irritancy and excellent in feeling of use. CONSTITUTION:This skin cosmetic comprises (A) 0.01-5.0wt.% gamma-aminobutyric acid and its derivative, e.g. N-methyl-gamma-aminobutyric acid or oleyl gamma- aminobutyrate, (B) 0.001-3.0wt.% glabridin which is a hydrophobic ingredient of Glycyrrhizae glabra var. glandulifera. The ingredient (B) can be obtained as a pure product of the glabridin by extracting a root of the GLycyrrhizae glabra var. glandulifera or its aqueous extraction residue (a residue after extracting glcycyrrhizin) with an organic solvent, distilling away the solvent from the resultant extract, treating the prepared extract according to the normal phase and reversed phase silica gel chromatographies and then crystallizing the glabridin.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is excellent in skin safety, has an effect of rapidly lightening dark skin and an effect of accelerating turnover speed of the stratum corneum, and has an excellent feeling of use. Highly effective skin cosmetics.

[0002]

2. Description of the Related Art UV rays cause inflammation (erythema) on the skin, and various factors are released to stimulate melanocytes. As a result, the color tone changes and blackens. This blackening is caused by the overproduction of melanin produced in melanocytes and delivered to epidermal cells, and melanin is produced by the oxidation of tyrosine.

Conventionally, in order to prevent skin blackening, stains and freckles and maintain the original white skin, skin cosmetics containing vitamin C derivative, hydroquinone monobenzyl ether, hydrogen peroxide and the like which prevent this oxidation. Is proposed.

However, when a vitamin C derivative is blended in these skin cosmetics, the storage stability is often insufficient or the whitening effect is not sufficiently observed in many cases. The addition of hydroquinone monobenzyl ether or the like to a whitening cosmetic has the effect of lightening dark skin, but has the drawback that there is a problem with skin safety. As described above, it is extremely difficult to obtain a skin cosmetic having an excellent whitening effect and high skin safety.

When glabridin, which is a hydrophobic component of licorice, is blended alone, antibacterial action, antioxidant action,
It has been confirmed that it has an anticariogenic action, an antiplasmin, and a melanin production inhibitory action. However, although the whitening effect was excellent, the usability was not fully satisfactory.

Further, γ-aminobutyric acid and its derivatives are known substances having peripheral vasodilatory action on the skin. When these are blended alone, a certain degree of skin metabolism promoting effect is obtained, but the feeling of use is not satisfactory.

[0007]

In view of such a situation, the inventors of the present invention have conducted diligent research to improve the drawbacks of the prior art, and as a result, have added glabridin and γ-aminobutyric acid and its derivatives. However, it has been found that the synergistic effect is remarkably excellent in the whitening effect, has the effect of enhancing the turnover rate of the stratum corneum, and has a skin safety with excellent feeling of use and high skin safety. I arrived.

[0008] That is, an object of the present invention is to provide a skin cosmetic having an excellent whitening effect, an effect of enhancing the turnover rate of the stratum corneum, a high skin safety and an excellent usability. It is a thing.

In order to achieve the above object, the skin cosmetic of the present invention has the following constitution. That is, the present invention is a skin cosmetic containing glabridin and at least one of γ-aminobutyric acid and its derivative.

Glabridin used in the skin cosmetic of the present invention is naturally a kind of licorice, Glycyrrhiza glab.
It is contained in a small amount in a Linne var. (commonly known as Russian, Afghan and Turkish liquorice). As a method for producing glabridin, licorice root or a water extraction residue thereof (for example, a residue obtained by extracting glycyrrhizin) is extracted with an organic solvent. Examples of the extraction solvent include lower aliphatic alcohols such as methanol and ethanol, lower aliphatic ketones such as acetone, ethers such as dioxane and ethyl ether, halogenated hydrocarbons such as methylene chloride, esters such as ethyl acetate, and hexane. It is possible to use a mixture of two or more kinds of organic solvents such as hydrocarbons. The licorice to be extracted is dipped in about 5 to 15 times the amount of the above solvent, and allowed to stand at room temperature or heated under reflux. The extract obtained by distilling the solvent off from the extract usually contains about 5 to 10% of glabridin. Purification can be carried out relatively easily by, for example, a method of treating by normal phase silica gel column chromatography and reverse phase silica gel column chromatography and then crystallizing from acetone to obtain a pure product of glabridin. In addition, purification can be performed by employing any organic compound purification means such as column chromatography using a synthetic adsorbent.

The γ-aminobutyric acid and its derivatives used in the skin cosmetics of the present invention are known compounds, and γ-aminobutyric acid (hereinafter abbreviated as GABA) and its derivative are N-.
Methyl-γ-aminobutyric acid (hereinafter abbreviated as MGA), N-dimethyl-γ-aminobutyric acid (hereinafter abbreviated as DMGA), γ-
There are N-alkyl compounds and esters such as aminobutyric acid oleyl ester (hereinafter abbreviated as GABAOE).

The amount of glabridin incorporated into the skin cosmetic of the present invention is preferably 0.001 based on the total amount.
˜3.0 wt% (hereinafter referred to as wt%).

The blending amount of γ-aminobutyric acid in the skin cosmetic of the present invention is a dry solid amount, and is preferably 0.01 to 5.0 wt% based on the total amount.

If the amount of glabridin is less than 0.001 w% and the amount of γ-aminobutyric acid and its derivative is 0.01 w%, the effect of the present invention is not sufficient, and the amount of glabridin is 3.0 w%. Even if the content of γ-aminobutyric acid and its derivative exceeds 5.0% by weight, the effect corresponding to the increase cannot be expected to be improved, the feel at the time of use tends to deteriorate, and it becomes difficult to maintain individual dosage forms.

The skin cosmetic of the present invention can be formulated into lotions, emulsions, creams, packs and the like according to a conventional method.

The skin cosmetic of the present invention may be appropriately mixed with a dye, a fragrance, an antiseptic, a surfactant, a pigment and the like within a range in which the object of the present invention is achieved.

[0017]

EXAMPLES The present invention will be described in detail below based on examples and comparative examples.

(1) Tyrosinase activity inhibition test (2) Skin color lightness recovery test (3) Whitening practical test (4) Corneal turnover speed measurement test (5) Optical patch test Is as follows.

(1) Tyrosinase activity inhibition test 0.3 m per 1 ml of McClubein buffer (pH 6.8)
A sample solution of each concentration is added to a tyrosine solution of g / ml concentration, and pre-incubation is performed at 37 ° C for 10 minutes. 1m to this
0.1 ml of tyrosinase (manufactured by Sigma) at a concentration of g / ml
Was added and heated at 37 ° C. for 15 minutes, and then the absorbance (A) was measured at a wavelength of 475 nm using a spectrophotometer. On the other hand, the absorbance (B) of 0.1 ml of buffer solution added in place of tyrosinase, 0.1% buffer solution in place of the sample solution.
The absorbance (C) of the solution added with ml and the absorbance (D) of the sample solution added with 0.2 ml of the buffer solution instead of tyrosinase were measured, and the inhibition rate (%) was calculated according to the following formula.

Inhibition rate (%) = {1- (AB) / (CD)} × 100

(2) Skin color lightness recovery test [0021] The skin of the upper arm of 20 test subjects was irradiated with the minimum erythema dose of UV rays in the UVA and UVB regions for 3 days continuously, and after the irradiation was completed, the sample application part and the base application part Standard lightness of skin (V0
Value, V0 'value) was measured. Subsequently, it was applied 3 times a day for 4 consecutive weeks, and the skin lightness (Vn value, Vn ′) of the sample-applied part and the base-applied part skin after 1, 2 and 4 weeks from the start of irradiation.
The value) was measured and the skin color recovery was evaluated according to the following criteria.

The brightness of the skin (V value of Munsell display system)
Was calculated from X, Y, and Z values obtained by measurement with a high-speed spectrocolorimeter. The evaluation is shown by the average value of the evaluation points of 20 test subjects after 4 weeks.

[0023]

[Table 1]

(3) Practical whitening test Left forearm flexion side part of the forearm flexion side skin of 20 test subjects exposed to summer sunlight for 3 hours (1.5 hours a day for 2 days) Samples on the skin from the day of exposure to sunlight
The base was applied to the right forearm flexion side skin once a day in the morning and continuously for 13 weeks from the day of exposure to sunlight.

The evaluation was shown by the number of test subjects whose effect of the sample application section was confirmed by the base application section.

(4) Turnover rate measurement test of stratum corneum Two skins of 20 forearm flexion lateral regions of 20 subjects were irradiated with 1.5 MED of UVB once, and after 3 days, dansyl chloride, which is a fluorescent dye, in white vaseline. 5% wt of ointment is applied to the skin of the irradiated part by occlusion for 24 hours, and dansyl chloride is permeated into the stratum corneum. After that, the sample and the base were applied to the same site three times a day (morning, noon, and after bathing), the fluorescence of dansyl chloride was examined every day, and the number of days until the fluorescence disappeared was examined and the turnover speed of the stratum corneum of the skin was determined. did.
The turnover speed of the normal stratum corneum is 14 to 1
6 days.

(5) Optical patch test After performing closed patch for 24 hours using a patch plate having a diameter of 1.0 cm, which is obtained by applying 0.05 g of the sample to the skin of the forearm flexor side of 25 subjects, the sunlight in summer is applied. 6 hours (3 a day
For 2 days).

The evaluation was carried out by subject 2 according to the following criteria.
The skin condition of 5 persons was evaluated and judged. Judgment result is irradiation 2
After 4 hours, the number of people was (±) or more.

[0029]

[Table 2]

(6) Sensory test Twenty test subjects evaluated the characteristics of the sample after continuously using the sample for 10 days.

The evaluation is based on the number of respondents who answered "wet skin has occurred", "good affinity to skin", "improved skin gloss" to questionnaire items such as wettability and affinity. Indicated.

Examples 1 to 3 and Comparative Examples 1 to 4 Two-Phase Lotion In the raw material composition shown in Table 3, the active ingredients are blended as shown in Table 3 to prepare a two-phase lotion, and the above-mentioned various tests are conducted. Was carried out.

[0033]

[Table 3]

[0034]

[Table 4]

(1) Preparation method Component B shown in Table 3 is uniformly dissolved in component A, and component C is uniformly dissolved in component D, then component A and component D are uniformly mixed and dispersed by stirring, and then filled in a container. To do. At the time of use, the contents should be evenly dispersed by shaking.

(2) Characteristics Table 4 shows the results of various tests. As shown in Table 4, Comparative Example 1 did not show good results in various tests.

The skin cosmetics of the present invention of Examples 1 to 3 showed clearly good results in all the tests, and no skin irritation occurred in the tests on human skin.

Examples 4 to 7 and Comparative Examples 5 to 8 Skin Cream The skin cream was prepared by blending the active ingredients as shown in Table 6 in the raw material composition of Table 5, and the above-mentioned various tests were carried out.

[0039]

[Table 5]

[0040]

[Table 6]

(1) Preparation method Component B shown in Table 5 is mixed with component A, and component A and component D are uniformly heated and dissolved to bring the temperature to 80 ° C. Then, the D component is poured into the A component and mixed by stirring, then cooled with stirring, and the C component is added at about 50 ° C. and cooled to 30 ° C.

The results of various tests are shown in Table 6. As shown in Table 6, Examples 4 to 6 clearly show good results in all the tests, good results in the tests with human skin, and no skin irritation in the tests with human skin. Did not happen.

As described above, it is apparent that the present invention provides a useful skin cosmetic having excellent whitening effect and horny layer turnover speed increasing effect, no skin irritation, and excellent feeling in use.

Claims (1)

[Claims] 1. A skin cosmetic containing at least one of γ-aminobutyric acid and its derivative and glabridin.