JP2511816B2 - Whitening cosmetics - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a whitening cosmetic composition having excellent skin safety, an effect of preventing dark skin, and an effect of rapidly lightening dark skin.

(Prior Art) It is said that the dark skin due to sunburn is based on the fact that tyrosine present in the skin is oxidized by the action of tyrosinase to become a melanin pigment, and this melanin is excessively produced. In order to prevent or treat this pigmentation, whitening cosmetics containing L-ascorbic acid and its derivatives, colloidal sulfur, hydrogen peroxide, hydroquinone, etc. have been proposed. However, these whitening cosmetics have insufficient storage stability, or have insufficient whitening effect, or have the effect of lightening dark skin, There is a problem in stability, and it has been difficult to obtain a whitening cosmetic excellent in the degree to which a whitening effect is positively expected.

Furthermore, the present inventors have proposed a whitening cosmetic containing a dibasic acid ester as described in JP-A-59-106411, and as a result of further research on the whitening cosmetic,
In the evaluation experiment method shown in the publication, although whitening and other effects are recognized, re-evaluation by the current improved substantial method does not always prevent dark-skinned skin and rapidly lightens dark-skinned skin. The effect to achieve, that is, the rapid whitening effect was not sufficiently exhibited to the extent expected by the present inventor. .

DISCLOSURE OF THE INVENTION Therefore, the present inventor has a problem of promptly eliminating melanin excessively present in the epidermis, suppressing new generation of melanin in the skin, and having a problem in skin safety. As a result of earnest research for the purpose of obtaining a whitening cosmetic satisfying the above-mentioned problems, a whitening cosmetic in which calcium fopanthenate and at least one selected from specific dibasic acid esters described below are used in combination is The inventors have found that the above objects can be achieved, and have completed the present invention.

(Object of the invention) That is, an object of the present invention is to provide an excellent whitening cosmetic composition which has no dermal irritation, an effect of suppressing melanin pigment formation, and an effect of rapidly lightening dark skin.

(Structure of the Invention) The present invention is a whitening cosmetic composition in which calcium fopanthenate and at least one of the specific dibasic acid esters described below are used in combination.

(Detailed Description of Configuration) Calcium hopanthenate used in the present invention is a known substance, and its pharmacological effect is to promote glucose uptake into the brain and its metabolism, and to prevent encephalitis sequelae and cerebral palsy. It is known to be a drug that is effective for treatment of associated hyperactivity, decreased attention, and speech disorders, and has few side effects.

The chemical properties and the like of calcium hopantenate are as follows.

(R _{1 in the} above structural formula represents a HOCH ₂ group, and R ₂ represents an NHCH ₂ CH ₂ CH ₂ COO group.) (2) Chemical name Calcium D-(+)-4- (2,4-dihydroxy-
3,3-Dimethyl butyroamide) Butyrate Hemihydrate Calcium D-(+)-4- (2,4-dihydroxy-3,3-di
methyl butyrate hemihydrat (3) General name: Calcium hopantenate (4) Molecular formula: C ₂₀ H ₃₆ CaNO ₅ 1 / 2H ₂ O (5) Molecular weight: 513.60 (6) Melting point: 155-165 ° C Calcium hopanthenate that can be added to the whitening cosmetics of
It was heated to obtain a suspension solution, and 1.2 g of γ-aminobutyric acid was added to and dissolved in the suspension solution. Next, 1.3 g of pantolactone was added, and the mixture was stirred for 2 hours, then left overnight, the solvent was distilled off, water was added to the precipitated white crystals to remove insoluble substances by centrifugation, and then water was evaporated.
After drying, white crystalline calcium hopantenate was obtained.

The calcium fopanthenate obtained by the above synthetic method was used in the tests of the present invention.

The dibasic acid ester represented by the following general formula (1) used in the present invention is a known substance.

General formula R ₁ OOC (CH ₂ ) _n COOR ₂ (1) (In the above formula, R ₁ is a linear alkyl or alkenyl group having 1 to 8 carbon atoms, R ₂ is a hydrogen atom or carbon It is a linear alkyl group or alkenyl group of the number 1 to 8, and n is 1 to 13
Is an integer. ) For example, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1.9-nonamethylenedicarboxylic acid, 1.10-decamethylenedicarboxylic acid monomethyl ester, monoethyl ester, monopropyl ester, etc.
Monobutyl ester, monoallyl ester, mono-2-
Heptenyl ester, dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester, dibenzyl ester, diallyl ester, di-2-butenyl ester, di-3-hexenyl ester and the like can be mentioned.
The present inventor examined the mechanism of action of calcium fopanthenate and dibasic acid ester, etc., for the skin that was naturally dark skin or that was darkened by the deposition of melanin pigment upon exposure to sunlight. However, the whitening cosmetic composition of the present invention obtained by blending the above-mentioned calcium hopanthenate and a dibasic acid ester,
The dibasic acid ester inhibits tyrosinase activity in the epidermis and inhibits the production of melanin pigment, and calcium fopanthenate further causes skin irritation even when applied to skin which is unstable in skin physiology after sunburn. Without causing it, it promotes blood circulation in the skin to enhance skin function, repairs or improves the function originally possessed by the skin to keep the skin in a healthy state, and quickly eliminates melanin together with the stratum corneum from the body. It was confirmed that the skin lightening effect was obtained. That is, the melanin pigment production inhibitory effect such as dibasic acid ester, and the skin function enhancing effect of calcium hopanthenate act synergistically, the melanin pigment is deposited on the fast-acting lightening of the black-black skin, and newly. It was confirmed that it has an excellent effect that the effect of preventing dark skin is developed.

The compounding amount of calcium hopanthenate is 0.05 to 2.0% by weight (hereinafter referred to as w) based on the total weight of the composition of the whitening cosmetic composition of the present invention.
abbreviated as t%), preferably 0.1 to 1.5 wt.
%. Further, the amount of the dibasic acid ester blended is 0.05 to
It should be 10.0 wt%.

Even if the blending amount of each of these substances exceeds the respective upper limits, the effect commensurate with the increased amount cannot be expected, and if the blending amount is less than the lower limit, the object of the present invention cannot be achieved.

The whitening cosmetic composition of the present invention can be applied to, for example, lotions, emulsions, creams, packs and the like.

In addition to the above, the skin cosmetics of the present invention include dyes, fragrances,
Preservatives, surfactants, pigments, antioxidants and the like can be appropriately added within the range where the object of the present invention is achieved.

(Example) Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples.

The skin irritation test, the stratum corneum turnover speed measurement test, the skin color brightness recovery test, and the whitening practical test described in Examples are shown below.

Skin irritation test 0.05g of sample was applied to the forearm flexor lateral skin of 25 subjects exposed to sunlight in summer for 6 hours (3 hours a day for 2 days) with a diameter of 1.0
After applying a patch test patch with a circular linen cloth of cm for 24 hours, according to the following criteria,
The skin condition of 25 subjects for each sample was evaluated and judged. As the determination result, the one with the strongest reaction was used after 1 hour and 24 hours after the removal of the plaster, and the evaluation was shown by the number of persons with (±) or more.

Keratin turnover velocimetry test 5w of fluorescent dye dansyl chloride in white petrolatum
An ointment containing t% was prepared and occluded and applied to the skin of the flexion side of the forearm of 20 subjects for 24 hours, and dansyl chloride was osmotically bonded to the stratum corneum. After that, on the same part twice a day (morning and evening)
The test sample was applied, the fluorescence of dansyl chloride was examined every day, and the number of days until the fluorescence disappeared was defined as the turnover rate of the stratum corneum of the skin. The measurement results are shown as the average number of days of each subject.

The normal turnover speed of the stratum corneum is 14-
16th.

Skin color lightness recovery test The back skin of 20 test subjects was irradiated with UV rays in the UV-B region at twice the minimum erythema dose, and 1 week later, the irradiation part was set to the sample application site and non-application site. The standard lightness (Vo value, Vo 'value) of each skin was measured. Subsequently, the sample was continuously applied to the application site once a day for 3 months, and the lightness (Vn ...
Value, Vn ′ ... value) and measure according to the following criteria.
A skin color recovery evaluation was performed.

The lightness (V value of Munsell color system) of the skin was calculated from the X, Y, and Z values obtained by measuring with a high-speed spectral colorimeter. Also,
The evaluation is shown by the average value of the evaluation points of 20 non-testers after 13 weeks.

Whitening Practical Test For the skin of the forearm flexor side of 25 subjects exposed to sunlight in summer for 3 hours (1.5 hours a day for 2 days), the left forearm flexor side was exposed to sunlight The sample was applied to the right forearm flexor lateral side from the day after the day and from the day 7 days after the day of being exposed to sunlight, once a day in the morning and once a day for 13 weeks. The evaluation is that the skin area where the sample is applied is lighter (lighter) than other skin areas.
It is shown by the number of subjects who answered.

Comparative Examples 1 to 7 and Examples 1 to 5 [Two-layer type lotion] Two-layer type lotions having the following compositions were prepared as shown in Table 1 and various tests were conducted. The results are shown in the right column of Table 1.

As the dibasic acid ester used in this example and the like, adipic acid monoethyl ester is abbreviated as AME, and hereinafter, azelaic acid diethyl ester is ADE and suberic acid mono-ester.
2-heptenyl ester is SMP, 1.9-nonamethylenedicarboxylic acid dipropyl ester is NMDDP, 1.9-nonamethylenedicarboxylic acid monobutyl ester is NMDMB, 1.10-decamethylenedicarboxylic acid monoallyl ester is DMDMA,
1.10-Decamethylenedicarboxylic acid di-2-butenyl ester is abbreviated as DMDDB.

(2) Preparation method Calcium fopanthenate in the component (B) is uniformly dissolved in the component (C), and the dibasic acid ester is also dissolved in the component (A) in advance, and then (A). The component and the component (C) are uniformly mixed and dispersed by stirring, and then filled in a container. At the time of use, the contents should be evenly dispersed by shaking.

(3) Properties As shown in Table 1, the two-layer lotion base of Comparative Example 1 and the whitening cosmetics of Comparative Examples 2 to 7 in which calcium phosphate and dibasic acid ester were individually added to the base. In comparison, the skin-whitening cosmetics containing calcium fopanthenate of Examples 1 to 5 and a combination of dibasic acid ester were used in all of the stratum corneum turnover speed measurement test, skin color lightness recovery test, and whitening practical test. Good evaluation was obtained over the entire period. Especially, the skin of the left forearm where the sample was applied from the day after the day when it was exposed to the sunlight when excess melanin was not yet formed in the skin was compared with the unapplied part of the right forearm. Thus, the effect of preventing dark skin was clearly recognized.

Comparative Examples 8 to 10 and Examples 6 to 8 [Skin Cream] Similar to Example 1, each skin cream having the following composition was prepared and various tests were conducted, and the results are shown in the right column of Table 1. It was shown to.

(2) Preparation Method Of the component (B), the dibasic acid ester is dissolved in the component (A) and the calcium fopanthenate is dissolved in the component (C), and then the components (C) and (A) are added. After being heated and melted at 80 ° C., the component (A) is poured into the component (C) and mixed by stirring. Then, the temperature is cooled to 30 ° C. with stirring.

(3) Properties As shown in Table 1, in contrast to Comparative Examples 8 to 10, Examples 6 to 8 which are whitening cosmetics of the present invention showed good results in all tests. In addition, as in Examples 1 to 5, particularly in the whitening practical test, the effect of preventing excessive melanin pigment deposition on the skin of the applied portion of the forearm and preventing it from becoming dark black is improved. It was recognized that

(Effects of the Invention) As described above, the whitening cosmetic composition of the present invention has high skin safety, and it is clear that it has an effect of suppressing melanin pigment formation and an effect of promptly lightening dark skin. It was confirmed that the whitening effect was further improved by using the composition immediately after being exposed to sunlight or the like.

Claims (2)

(57) [Claims] 1. A whitening cosmetic comprising a mixture of calcium hopanthenate and at least one dibasic acid ester represented by the following general formula (1). General formula ……………… R ₁ OOC (CH ₂ ) _n COOR ₂ ………… (1) (In the above formula, R ₁ is a linear alkyl or alkenyl group having 1 to 8 carbon atoms, R _{1 2} is a hydrogen atom or a linear alkyl group or alkenyl group having 1 to 8 carbon atoms, and n is 1 to 13
Is an integer. ) 2. The whitening cosmetic composition according to claim 1, wherein the dibasic acid ester is a monoester or diester represented by the general formula.