JP3115445B2 - Whitening cosmetics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a whitening cosmetic having excellent skin safety, an effect of preventing dark-skinned skin, and an effect of rapidly lightening dark-skinned skin.

[0002]

2. Description of the Related Art The dark-skinned skin caused by sunburn is caused by the fact that tyrosine present in the skin is oxidized by the action of tyrosinase to form melanin pigment, and this melanin is excessively produced. Have been. In order to prevent or treat this pigmentation, there has been proposed a whitening cosmetic composition containing L-ascorbic acid and its derivatives, colloidal sulfur, hydrogen peroxide, hydroquinone and the like. However, these whitening cosmetics have insufficient storage stability, or do not have a sufficient whitening effect, or have an effect of lightening dark-skinned skin. This poses a problem in terms of safety, and it has been difficult to obtain an excellent whitening cosmetic.

[0003] Accordingly, the present inventor has sought to quickly eliminate melanin excessively present in the epidermis, suppress the production of new melanin in the skin, and
With the aim of providing a whitening cosmetic that satisfies no problem in skin safety, etc., intensive research was conducted. As a result, the inventor
The present inventors have found that the whitening cosmetics described below achieve this object, and have completed the present invention.

[Means for Solving the Problems]

That is, the present invention provides at least one selected from the group consisting of γ-amino-β-hydroxybutyric acid and salts thereof,
An object of the present invention is to provide a whitening cosmetic comprising a mixture of ribonucleic acid, deoxyribonucleic acid and one selected from the group consisting of salts thereof.

[0005] Skin cosmetics containing GABOB alone have an effect of preventing skin aging by activating skin tissue (Japanese Patent Application Laid-Open No. 62-255405). Hereinafter, the configuration of the present invention will be described in detail.

[0006] GABOB used in the present invention is a known substance and has been applied as a therapeutic agent for cerebral arteriosclerosis.
Its chemical properties are as follows:

[0007]

[Table 1]

The potassium salt, sodium salt, calcium salt and magnesium salt of GABOB obtained by neutralizing GABOB with caustic potash, caustic soda or calcium hydroxide or magnesium hydroxide are all used as the whitening cosmetic of the present invention. Applied.

The "nucleic acids" selected from the group of ribonucleic acid, deoxyribonucleic acid and salts thereof according to the present invention are known substances, and their salts include ribonucleic acid or deoxyribonucleic acid, inorganic bases and A salt comprising an organic base is applied, preferably a sodium salt or a potassium salt of ribonucleic acid or deoxyribonucleic acid, particularly preferably a lysine salt or an arginine salt.

[0010] GABOB and its salts have the effect of activating skin tissue, accelerating the turnover rate of the skin, and rapidly eliminating melanin together with the stratum corneum to lighten and normalize pigmentation.

The above-mentioned "nucleic acids" to be added to the whitening cosmetic composition of the present invention have an effect of suppressing the melanin-forming ability of the skin and preventing the skin from becoming a new dark-skinned skin.

A whitening cosmetic containing at least one selected from the group consisting of GABOB and its salt and a nucleic acid is excellent in a pigmentation improving effect, a lightening preventing effect, a skin roughening preventing effect, a moisturizing effect, etc. by a synergistic effect. Is expressed. The whitening cosmetic composition of the present invention is applied to skin before becoming dark or darkened after exposure to sunlight, particularly to skin that is unstable in skin physiology, and is intended to stimulate skin. It has a remarkable effect in lightening the dark skin without causing any coloration.

The inventor of the present invention has investigated the proportions of the above-mentioned constituents to be incorporated in a whitening cosmetic composition in order to maximize the synergistic effect, and found that (I) GABOB and its salts, (I)
I) It is preferable that the ratio (weight ratio) of each compounding amount of the nucleic acids is (I) :( II) = 1: 0.01 to 10, and the excellent effect aimed at by the present invention was recognized. .

The amount of GABOB and nucleic acids in the whitening cosmetic is 0.05% (I) based on the total amount.
-3.0 wt%, and (II) may be 0.05-3.0 wt%. If the amounts are less than the lower limits, the effects intended by the present invention are not sufficient. On the other hand, if the amounts exceed the upper limits, the effect corresponding to the increase cannot be expected.

[0015] In addition to the above, various oils, wetting agents, pigments, fragrances, preservatives, surfactants, pigments, antioxidants, and the like are appropriately added to the whitening cosmetic of the present invention as long as the object of the present invention is achieved. can do.

[0016]

The present invention will be described below with reference to examples. Prior to Examples, (1) skin irritation test, (2) stratum corneum turnover speed measurement test, (3) skin color brightness recovery test,
(4) Describe the method of practical whitening test.

(1) Skin irritation test 0.05 g of a sample having a diameter of 1.0 cm was placed on the skin of the flexion side of the forearm of 25 subjects exposed to the sunlight of summer for 6 hours (3 hours a day for 2 days). After 24 hours of obstruction and application using a patch test patch with a circular lint cloth, the skin condition of 25 subjects was evaluated and determined for each sample according to the following evaluation criteria. The judgment results were 1 hour after bandage removal and 24 hours.
The one with the strongest response after time was adopted, and the number of people with an evaluation of (±) or more was indicated.

[0018]

[Table 2]

(2) Test for measuring the turnover speed of the stratum corneum The fluorescent dye dansyl chloride was added to white vaseline in an amount of 5 wt.
% Ointment is prepared and adhered to the skin on the flexion side of the forearm of 20 subjects for 24 hours, and dansyl chloride is penetrated into the stratum corneum. Then twice a day at the same site (morning and evening)
The test sample was applied and the fluorescence of dansyl chloride was examined every day. The number of days until the fluorescence disappeared was defined as the turnover speed of the stratum corneum of the skin. The measurement results were shown as the average of the number of days for each subject. In addition, the turnover speed of the normal skin stratum corneum is 14 to 16 days.

(3) Skin color lightness recovery test The back skin of the 20 test subjects was irradiated with ultraviolet rays in the UV-B region twice as much as the minimum erythema dose. The reference lightness (Vo value, Vo 'value) of each skin was measured by setting the and the non-application site. Subsequently, the sample was continuously applied to the application site once a day for three months.
The lightness (Vn... Value, Vn ′... Value) of the skin at the application site and the non-application site after 8 and 13 weeks was measured, and the evaluation of skin color recovery was performed according to the following evaluation criteria. The lightness (V value of Munsell color system) of the skin was calculated from X, Y, and Z values obtained by measuring with a high-speed spectral colorimeter. In addition, the evaluation
The average value of the evaluation values of 13 subjects after 13 weeks was shown.

[0021]

[Table 3]

(4) Practical whitening test The left forearm flexed side skin of the forearm flexed skin of 20 subjects exposed to the sunlight of summer for 3 hours (1.5 hours a day for 2 days) On the right forearm flexion side, samples were applied once a day in the morning and evening for 13 weeks on the right forearm flexing side, respectively, 7 days after the day exposed to sunlight. The evaluation was indicated by the number of subjects who answered that the skin portion to which the sample was applied became lighter (lighter) than the other skin portions.

Examples 1 to 4 and Comparative Examples 1 to 4 (two-layer type lotion) In the composition of Table 4, GABOB was used as shown in the left column of Table 5.
Each double-layer lotion was prepared by changing the amounts of the nucleic acids and nucleic acids. (1) Composition

[0024]

[Table 4]

[0025]

[Table 5]

(2) Preparation method After the components (A) and (B) are uniformly dissolved, the components (A) and (B) are mixed, dispersed by stirring, and then filled in a container. When used, the contents are shaken and dispersed uniformly.

(3) Characteristics Various tests were carried out using this as a sample. The results are shown in the right column of Table 5.

As shown in Table 5, the two-layer type lotion bases of Comparative Examples 1 to 4 and the lotion in which GABOB and its salts and nucleic acids were individually added to the bases had slightly higher stratum corneum turnover rates. Although the effect of shortening the number of days can be recognized, sufficient effects cannot be obtained in the skin color brightness recovery test and the whitening practical test. The whitening cosmetics of the present invention of Examples 1 to 4 all have good evaluations in various tests.

Examples 5 to 9 and Comparative Examples 5 to 7 (skin cream) In the same manner as in Example 1, in the composition of Table 6, the following preparation method was carried out using the amounts of GABOB and nucleic acids shown in the left column of Table 7 To prepare each skin cream.

(1) Composition

[0031]

[Table 6]

(2) Preparation method The components (A) and (B) are each uniformly heated and dissolved to a temperature of 8
After the temperature is brought to 0 ° C., the component (A) is poured into the component (B) and mixed with stirring. Then, the temperature is cooled to 30 ° C. while stirring. (3) Characteristics Various tests were conducted, and the results are shown in the right column of Table 7.

[0033]

[Table 7]

As shown in Table 7, Examples 5 to 9, which are the whitening cosmetics of the present invention, show good results in various tests and excellent whitening effects as compared with Comparative Examples 5 to 7. Was evident.

[0035]

As described above, it is apparent that the whitening cosmetic of the present invention has high skin safety, has an effect of suppressing melanin pigment formation and an effect of rapidly lightening dark skin, as described above. In particular, it was recognized that the whitening effect was further improved by using the product immediately after exposure to sunlight or the like.

Claims (1)

(57) [Claims] 1. A whitening method comprising mixing at least one selected from the group consisting of γ-amino-β-hydroxybutyric acid and salts thereof and one selected from the group consisting of ribonucleic acids, deoxyribonucleic acids and salts thereof. Cosmetics.