JP2731329B2 - Skin cosmetics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in skin safety, has the effect of rapidly lightening dark-skinned skin and the effect of increasing the turnover speed of the stratum corneum, and has an excellent feeling in use. Highly skin cosmetics.

[0002]

2. Description of the Related Art Ultraviolet rays cause inflammation (erythema) on the skin and release various factors to stimulate melanocytes. As a result, the color tone changes and blackens. This darkening is due to overproduction of melanin, which is produced in melanocytes and passed to epidermal cells, and is produced by oxidation of tyrosine.

[0003] Conventionally, skin cosmetics containing a derivative of vitamin C, hydroquinone monobenzyl ether, hydrogen peroxide, etc., for preventing oxidation, in order to prevent darkening, spots and freckles on the skin and to maintain the original white skin. Has been proposed.

[0004] However, when a vitamin C derivative is incorporated into these skin cosmetics, the storage stability is often insufficient or the whitening effect is not sufficiently recognized. When hydroquinone monobenzyl ether or the like is blended in a whitening cosmetic, it has the effect of lightening dark-skinned skin, but has drawbacks such as a problem in skin safety. As described above, it is extremely difficult to obtain a skin cosmetic having an excellent whitening effect and high skin safety.

[0005] In addition, when glabridine, which is a hydrophobic component of licorice, is blended alone, the antibacterial action, antioxidant action,
It has been confirmed that it has an antinociceptive effect, an antiplasmin and an inhibitory effect on melanin production. However, although the whitening effect was excellent, the feeling of use was not sufficiently satisfactory.

[0006] Also, γ-aminobutyric acid and its derivatives are substances known to have a peripheral vasodilatory effect on the skin. When these are used alone, a certain degree of skin metabolism promoting effect can be obtained, but the feeling of use has not been satisfactory.

[0007]

Means for Solving the Problems In view of such circumstances, the present inventors have conducted intensive studies to improve the disadvantages of the prior art, and as a result, a compound obtained by combining glabridine with γ-aminobutyric acid and a derivative thereof. However, it has been found that the synergistic effect is remarkably excellent in whitening effect, has an effect of enhancing the turnover speed of the stratum corneum, and is a skin cosmetic with high feeling of use and high skin safety, and has been completed in the present invention. Reached.

[0008] That is, an object of the present invention is to provide a skin cosmetic composition which is excellent in whitening effect, has an effect of increasing the turnover speed of the stratum corneum, has high skin safety and is excellent in use feeling. Things.

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 comprising glabridine and at least one of γ-aminobutyric acid and a derivative thereof.

Glabridin used in the skin cosmetic composition of the present invention is naturally a kind of licorice, Glycyrrhiza glab
a A trace amount is contained in Linne var. (commonly known as Russia, Afghanistan and Turkey licorice). As a method for producing grabradine, 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. And mixtures of two or more organic solvents such as hydrocarbons. The licorice to be extracted is immersed in about 5 to 15 times the amount of the above solvent, and left standing at room temperature or heated under reflux. The extract obtained by distilling off the solvent from the extract usually contains about 5 to 10% of glabridine. For purification, a pure glabridine product can be obtained relatively easily by, for example, a method of treating with normal-phase silica gel column chromatography and reverse-phase silica gel column chromatography and then crystallization from acetone. Purification can be performed by any other means for purifying organic compounds such as column chromatography using a synthetic adsorbent.

Γ-Aminobutyric acid and its derivatives used in the skin cosmetic of the present invention are known compounds, and γ-aminobutyric acid (hereinafter abbreviated as GABA) and 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 oleyl aminobutyrate (hereinafter abbreviated as GABAOE).

The amount of glabridine in the skin cosmetic composition of the present invention is preferably 0.001% based on the total amount.
To 3.0% by weight (hereinafter referred to as wt%).

The amount of γ-aminobutyric acid in the skin cosmetic composition of the present invention is preferably 0.01 to 5.0% by weight, based on the total amount of dry solids.

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

The skin cosmetic composition of the present invention can be made into a dosage form such as lotions, emulsions, creams, packs, etc. according to a conventional method.

The skin cosmetics of the present invention can be appropriately blended with pigments, fragrances, preservatives, surfactants, pigments and the like within a range that achieves the object of the present invention.

[0017]

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

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

(1) Tyrosinase activity inhibition test 0.3 m per 1 ml of McClubine buffer (pH 6.8)
The sample solution of each concentration is added to the tyrosine solution having a concentration of g / ml, and preliminarily kept at 37 ° C. for 10 minutes. 1m to this
0.1 ml of tyrosinase (manufactured by Sigma) at a concentration of g / ml
After heating at 37 ° C. for 15 minutes, the absorbance (A) was measured at a wavelength of 475 nm using a spectrophotometer. On the other hand, the absorbance (B) obtained by adding 0.1 ml of buffer solution instead of tyrosinase,
The absorbance (C) of the solution to which the solution had been added and the absorbance (D) of the solution to which 0.2 ml of the buffer had been added instead of the sample solution and tyrosinase were measured, and the inhibition rate (%) was calculated according to the following formula.

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

(2) Skin lightness recovery test The skin of the upper inner arm of the 20 test subjects was continuously irradiated with the minimum amount of UVA and UVB erythema in the UVA and UVB regions for 3 days. After the irradiation was completed, the sample application section and the base application section were applied. Reference lightness of skin (V0
(V0 'value) was measured. Subsequently, the composition was applied three times a day for four consecutive weeks, and the skin lightness (Vn value, Vn ′) of the sample-applied part and the base-applied part at 1, 2, and 4 weeks after the start of irradiation
Was measured, and the skin color was evaluated for recovery 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 measuring with a high-speed spectral colorimeter. The evaluation was shown as an average of the evaluation points of the 20 test subjects after 4 weeks.

[0023]

[Table 1]

(3) Practical skin whitening test The left forearm flexing side skin of 20 test subject's forearm flexing side skin exposed to sunlight in summer for 3 hours (1.5 hours a day for 2 days). From the day of sun exposure to the skin,
The base was applied to the right forearm flexion side skin once a day in the morning and evening for 13 weeks from the day of exposure to sunlight.

The evaluation was made based on the number of subjects who confirmed the effect of the sample application section from the base application section.

(4) Test for measuring the turnover speed of the stratum corneum Twenty subjects were irradiated once with 1.5 MED UVB at two sites on the flexor side of the forearm. Three days later, dansyl chloride, a fluorescent dye, was placed in white petrolatum. Ointment mixed with 5% by weight is applied to the irradiated skin for 24 hours, and dansyl chloride is penetrated into the stratum corneum. Thereafter, a sample and a base are applied to the same site three times a day (morning, afternoon, after bathing), and the fluorescence of dansyl chloride is examined every day. The number of days until the fluorescence disappears is determined, and the turnover speed of the stratum corneum of the skin is determined. did.
In addition, the normal skin stratum corneum turnover speed is 14 to 1
Six days.

(5) Optical Patch Test Closed patching was performed for 24 hours using a 1.0 cm diameter patch plate on which 0.05 g of a sample was applied to the skin of the flexed side of the forearm of 25 subjects. 6 hours (3 days a day)
Irradiation for 2 days).

The evaluation was performed according to the following criteria.
The skin condition of five persons was evaluated and evaluated. The judgment result is irradiation 2
Four hours later, the number was indicated by (±) 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 was based on the questionnaire items such as wettability and affinity, and the number of respondents who answered "moistened skin", "good affinity for skin" and "improved skin luster". Indicated.

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

[0033]

[Table 3]

[0034]

[Table 4]

(1) Preparation Method After dissolving the B component and the C component uniformly in the A component and the D component described in Table 3, the A component and the D component are uniformly mixed, stirred and dispersed, and then filled in a container. I do. When used, the contents are shaken and dispersed uniformly.

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

Examples 4 to 7, Comparative Examples 5 to 8 Skin Cream In the raw material composition shown in Table 5, active ingredients were blended as shown in Table 6 to prepare a skin cream, and the above-mentioned tests were carried out.

[0039]

[Table 5]

[0040]

[Table 6]

(1) Preparation method The B component shown in Table 5 is mixed with the A component, and the A component and the D component are each uniformly heated and dissolved to bring the temperature to 80 ° C. Next, the component D is injected into the component A, mixed with stirring, cooled while stirring, and the component C is introduced at about 50 ° C. and cooled to 30 ° C.

Table 6 shows the results of the tests. As shown in Table 6, Examples 4 to 6 showed clearly good results in all tests, good results in tests on human skin, and skin irritation in tests on human skin. Did not occur.

As described above, it is apparent that the present invention provides a useful skin cosmetic which has an excellent whitening effect and an effect of enhancing the turnover speed of the stratum corneum, has no skin irritation, and has an excellent feeling upon use.

Claims (1)

(57) [Claims] 1. A skin cosmetic comprising at least one of γ-aminobutyric acid and its derivatives and glabridine.