JPH11209235A - Skin whitening cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sking whitening cosmetic having excellent inhibitory effects on inflammation of the skin by ultraviolet rays, inhibitory effects on production of melanin pigment and rapid skin lightening of skin pigmentation free from skin irritation, by making the cosmetic include a specific compound. SOLUTION: This skin lightening cosmetic is formulated with preferably 0.001-5.0 wt.% of at least one selected from among compounds of formula I [R1 and R2 are each H, CH3 , C2 H5 , C3 H7 or CH(CH3 )2 ] and formula II [R3 and R4 are each H, CH3 , C2 H5 , C3 H7 or CH(CH3 )2 ]. For example, a synthetic substance obtained by condensing acetone with benzaldehyde, a substance obtained by extraction from a natural substance or a product on the market, to be concrete, 1,5-bis[p-hydroxyphenyl]-1,4-pentadiene-3-one or the like may be cited as the compound of formula I or formula II.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a skin without irritation.
The present invention relates to a useful whitening cosmetic having an excellent effect of suppressing inflammation of the skin by ultraviolet rays and an effect of suppressing the production of melanin pigments, and an excellent effect of rapidly lightening the pigmentation of the skin.

[0002]

2. Description of the Related Art The color tone of the skin is changed by the ultraviolet rays and blackened. Blackening is caused by overproduction of melanin, which is produced in melanocytes and passed to epidermal cells, and it is known that tyrosine is oxidized and produced.

Hitherto, as whitening cosmetics for the purpose of preventing or treating skin darkening, spots and freckles, ascorbic acid and derivatives thereof, hydroquinone derivatives, pyrones such as kojic acid, placenta such as placenta extract, etc. An extract containing an extract or the like has been proposed. These substances are disclosed as substances having a whitening effect such as suppression of melanin production and the effect of pale bleaching action of the produced melanin.

[0004] However, these substances, for example, ascorbic acid and its derivatives, often have insufficient storage stability or do not sufficiently show the effect of preventing inflammation caused by ultraviolet rays. Hydroquinone derivatives also have problems such as insufficient safety. As described above, it is actually difficult to obtain a whitening cosmetic composition which is entirely superior in terms of melanin production inhibitory effect, melanin pale bleaching effect, anti-inflammatory effect, safety and the like.

[0005] Therefore, an object of the present invention is to provide an excellent effect of suppressing skin inflammation due to ultraviolet rays and suppressing the production of melanin pigment without causing skin irritation, and further excellent effect of rapidly fading the pigmentation of the skin. It is to provide a natural whitening cosmetic.

[0006]

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, have been shown by the following general structural formula (1) or (2). Cosmetics containing at least one compound selected from the following compounds have no skin irritation, have an effect of suppressing skin inflammation due to ultraviolet rays, an effect of suppressing the production of melanin pigment, and an effect of rapidly lightening pigmentation of skin. The inventors have found that the present invention is excellent and completed the present invention.

[0007]

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[0008]

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That is, the present invention provides a whitening cosmetic comprising at least one compound selected from compounds represented by the following general structural formula (1) or (2) (hereinafter abbreviated as PhPDO). It is.

[0010]

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[0011]

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[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

PhPD used in the whitening cosmetic of the present invention
Examples of O include those obtained by a known synthesis method, for example, the condensation of acetone and a benzaldehyde compound, and those extracted and prepared from natural products and commercially available products. Specifically, 1,5-bis [p-hydroxyphenyl] -1,4-pentadien-3-one,
1,5-bis [o-hydroxyphenyl] -1,4-
Pentadien-3-one, 1,5-bis [2,4-dihydroxyphenyl] -1,4-pentadien-3-one, 1,5-bis [3-methoxy-4-hydroxyphenyl] -1,4 -Pentadien-3-one and the like.

The amount of PhPDO used in the present invention in a whitening cosmetic is 0.1% based on the total amount.
It is preferably from 001 to 5.0% by weight (hereinafter referred to as wt%).

The dosage form of the whitening cosmetic of the present invention includes lotions, emulsions, creams, packs and the like.

The whitening cosmetic composition of the present invention may 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.

Each of the tests (1) UV erythema suppression test, (2) tyrosinase activity inhibition test, (3) skin color lightness recovery test, (4) whitening practical test, and (5) light patch test described in the Examples. The method is as follows.

(1) UV erythema suppression test The hair on the back skin of 10 Hartley-type guinea pigs,
Two times each of the minimum erythema amount of the ultraviolet rays in the UVB region is irradiated at each of two locations. The sample is applied 24 hours before and immediately after the irradiation, the sample application site and the base application site are set, and the erythema state 24 hours later is evaluated according to the criteria shown in Table 1.

[0020]

[Table 1]

(2) Tyrosinase activity inhibition test [0021] 0.3 ml was added to 1 ml of McClubine buffer (pH 6.8).
A tyrosine solution having a concentration of mg / ml and a sample solution having each concentration are added, and preliminarily maintained 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 sample solution and the absorbance (D) of the sample solution and 0.2 ml of a buffer solution instead of tyrosinase were measured, and the inhibition rate (%) was calculated according to the following formula.

[0022]

(Equation 1)

(3) Skin color lightness recovery test The skin of the upper inner arm of the 20 test subjects was continuously irradiated with the minimum erythema of UVA and UVB in the UVA and UVB regions for 3 days. The reference lightness (V0 value, V0 'value) of the cream-applied skin was measured. Subsequently, application was performed three times a day for four consecutive weeks, starting irradiation 1,
After 2 or 4 weeks, the skin lightness (Vn value, Vn 'value) of the skin where the sample cream was applied and the base cream was applied was measured.
The skin color recovery was evaluated according to the criteria shown in Table 2.

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

[0025]

[Table 2]

(4) Practical whitening test The skin of the forearm flexed side of 20 test subjects was exposed to sunlight in summer for 3 days.
Exposure time (1.5 hours a day for 2 days). A sample of 5 mg / cm ^{2 in} the left forearm flexor skin from the day exposed to sunlight and the right forearm flexor skin from 7 days after the day exposed to sunlight (Example) And the base (comparative example) once in the morning and evening,
It was applied continuously for 13 weeks. In addition, the evaluation is shown by the number of subjects for which the effects of the base application section and the sample application section were remarkably confirmed.

(5) Optical Patch Test Closed patches were applied to the skin of the flexion side of the forearm of 25 subjects for 24 hours using a patch plate having a diameter of 1.0 cm to which 0.05 g of a sample was applied. For 6 hours (1
(3 hours a day for 2 days).

The evaluation was performed according to the criteria shown in Table 3.
The skin condition of each name was evaluated and judged. The judgment result is irradiation 24
After the time, the number is indicated by (±) or more.

[0029]

[Table 3]

Examples 1 to 6, Comparative Example 1 Two-Phase Lotion In the raw material composition shown in Table 4, the chemical formula 7 (PhPDO-1,
2), 8 (PhPDO-3, 4), 9 (PhPDO)
Each of the active ingredients of -5 and 6) was blended as shown in Table 5 to prepare a two-phase lotion, and the above-mentioned tests were carried out.

[0031]

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[0032]

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[0033]

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[0034]

[Table 4]

[0035]

[Table 5]

(1) Preparation method The B component shown in Table 4 was uniformly dissolved in the A component,
The component and the C component are uniformly mixed, stirred and dispersed, and then filled into a container. When used, the contents are shaken and dispersed uniformly.

(2) Characteristics The results of various tests are shown in Table 5. As shown in Table 5, the two-phase lotions of the present invention of Examples 1 to 6 showed clearly good results in all tests, and no skin irritation occurred in tests on human skin. On the other hand, the sample of Comparative Example 1 was inferior to those of the Examples in various tests.

Examples 7 to 12, Comparative Example 2 Skin cream In the raw material composition shown in Table 6,
8), Chemical Formula 11 (PhPDO-9, 10), Chemical Formula 12 (PhPDO-9, 10)
Each of the active ingredients of PDO-11 and 12) was blended at a concentration as shown in Table 5 to prepare a skin cream, and the above-described tests were performed.

[0039]

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[0040]

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[0041]

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[0042]

[Table 6]

(1) Preparation method The B component shown in Table 6 is mixed with the A component, and the A component and the C component are each heated and dissolved uniformly to bring the temperature to 80 ° C.
Next, the component C is injected into the component A, mixed with stirring, and then cooled to 30 ° C. with stirring.

Table 5 shows the results of the tests. As shown in Table 5, the skin creams of the present invention of Examples 7 to 12 showed clearly good results in all of the tests, and no skin irritation occurred in the tests on human skin. On the other hand, those of Comparative Example 2 were inferior to those of Examples in various tests.

[0045]

As described above, the present invention has no skin irritation, is excellent in the effect of suppressing skin inflammation due to ultraviolet rays, the effect of suppressing the production of melanin pigments, and the effect of rapidly lightening the pigmentation of the skin. It is clear that it provides an excellent and very useful whitening cosmetic.

Claims (1)

[Claims] 1. A whitening cosmetic comprising at least one compound selected from the compounds represented by the following general structural formulas (1) and (2): Embedded image