JP3534941B2 - Anti-aging skin cosmetics - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin aging preventive cosmetic, and more particularly, to an excellent anti-aging effect (rough skin improving effect, keratin improving effect, turnover speed). The present invention relates to a skin aging preventive cosmetic which is excellent in expressing and imparting a beautiful skin effect. 2. Description of the Related Art Aged skin becomes rough and dry without smoothness, and keratinocyte exfoliation is observed. It is said that the aging skin has a slow turnover speed, and that when the antiaging effect is exerted and imparted to the skin, the skin turnover speed increases. Conventionally, various cosmetics have been proposed which give a suitable wet feeling and flexibility to the skin surface. For example, Japanese Patent Application Laid-Open No. 4-99707 discloses R-
(-) Skin cosmetics containing mevalonic acid have been proposed. However, these skin cosmetics act on the epidermis of the skin tissue, but rarely act on the dermis, which is a tissue under the epidermis, and therefore have the effect of simply providing a feeling of moistness and flexibility to the skin. Although it can be expected, a sufficient effect of preventing skin aging cannot be obtained. An object of the present invention is to provide an anti-aging effect (an effect of improving rough skin, an effect of improving keratin, an effect of increasing the speed of turnover), and an effect of preventing skin aging which exhibits and imparts a beautiful skin effect. To provide cosmetics. [0004] The above objects SUMMARY In order to achieve the above, one or more selected from (a) mevalonic acid, mevalonic acid lactone
0.001 to 10% by weight and (b) 0.001 to 3.0% by weight of at least one selected from the group consisting of diisopropylamine dichloroacetate, urea, lactic acid and salts thereof, to prevent skin aging. Achieved by DETAILED DESCRIPTION OF THE INVENTION Mevalonic acid used as the component (a) in the present invention is also called burnt acid (molecular formula: C ₆ H ₁₂ O ₄ ).
lulus homeochichi and L. et al. hetero
chichi), and lactic acid bacteria (L. a.
and a precursor of biosynthesis of isoprenoid-based compounds such as sterols, or raw materials for chemically or enzymatically synthesizing various optically active substances. Mevalonic acid has two isomers [R (-)-mevalonic acid, S (+)
-Mevalonic acid] and naturally occurring R (-)-
Although mevalonic acid can be used in the present invention, R (-)-mevalonic acid, which is easily available, is preferable.
R (-)-mevalonic acid is disclosed in, for example, JP-A-63-216.
484, JP-A-63-216485, JP-A-63-216486, and JP-A-63-21648.
It can be produced by the microbial fermentation method described in Japanese Patent Publication No. 7 (1995). Alternatively, it can be produced as a racemate (mixture of isomers) by a chemical synthesis method, and it is also possible to isolate and use each isomer. Further, in the present invention, (a)
Mevalonate lactone (molecular formula: C ₆ H ₁₀ O ₃ ), which is a derivative of mevalonic acid used as a component, is a compound having a property of easily changing to mevalonic acid by hydrolysis. [0006] On the other hand, the component (b) used in the present invention is a compound known as a skin activating substance, and is known as diisopropylamine dichloroacetate (hereinafter referred to as DAD).
Abbreviated as A. ) Is proposed in JP-A-53-136528, which is incorporated into skin cosmetics. Urea is also a substance widely used in skin cosmetics as a skin tissue activating component. Furthermore, lactic acid and its salts as well, Ru substance der used in skin cosmetics. In the present invention, the component (b) is used in combination with the component (a) mevalonic acid and lactone mevalonate, and the synergistic effect of the component (b) results in a remarkable anti-aging effect (rough skin improving effect,
Keratin improvement effect, effect of increasing turnover speed),
The beautifying effect is expressed and imparted in a short period of time. [0007] (a) in the skin anti-aging cosmetic composition of the present invention
One or more suitable amounts of the components mevalonic acid and mevalonate lactone are 0.001 to 10% by weight (hereinafter abbreviated as wt%) , based on the total amount of the skin aging preventive cosmetic. Preferably 0.01 to 2.0 wt%
It is. Component (b) of diisopropylamine dichloroacetate, urea, lactic acid and the amount of one or more kinds selected from the group consisting of a salt thereof is 0.001～3.0Wt%, particularly preferably 0.01~2.0wt %. Furthermore, component (b) is 0.1 to 10 with respect to component (a).
It is preferable to mix them in a double amount (weight). [0008] The dosage form of the skin aging preventive cosmetic of the present invention is not particularly limited, and is applied to ordinary skin cosmetic dosage forms such as cream, emulsion, lotion, ointment, powder and the like. can do. In addition, the skin aging preventive cosmetic of the present invention comprises, as other components, an emulsifier, an oily substance, a humectant, a thickener, a fragrance, a preservative, an antioxidant, a colorant, etc. It can be appropriately compounded within. The present invention will be described in detail below based on examples and comparative examples. In the examples, (1) the method for measuring the turnover speed of the stratum corneum, (2) the method for measuring the effect of improving rough skin, (3) the method for measuring the effect of improving stratum corneum, and (4) the sensory test are as follows. . (1) Method for measuring the turnover speed of the stratum corneum 5% by weight of dansyl chloride, a fluorescent dye, was added to white petrolatum.
% Ointment was prepared and applied to the skin of the forearm of 20 subjects by occlusion for 24 hours, and dansyl chloride was osmotically bonded to the stratum corneum. Thereafter, the test sample was applied to the same site twice a day (morning and evening), and the fluorescence of dansyl chloride was examined every day.
The number of days until the fluorescence disappeared was defined as the skin stratum corneum turnover speed. The measurement results were shown as an average of the number of days for each subject. In addition, the normal skin stratum corneum turnover is 1
4-16 days, but extends to around 18 days in aged skin. On the other hand, when the anti-aging effect appears, 12
It will be shortened to around days. (2) Method of Measuring the Effect of Improving Rough Skin The effect of continuous application for four weeks was examined on 20 middle-aged subjects having rough skin on the lower leg. That is, a test sample is applied to the left lower leg test site of the subject twice a day (morning and evening),
The skin condition before and after the start of the test was determined according to the criteria shown in Table 1 below. The lower leg on the right side was used as a control without applying the test sample. [Table 1] By comparing the results of the judgment between the test site and the control site before and after the test, if the skin dryness is improved by two or more stages (for example: + → −, ++ → ±), “effective” is improved by one stage. In the case where there was no change, it was regarded as "slightly valid", and in the case where there was no change, it was "invalid". The test results were indicated by the number of subjects who became “effective” and “slightly effective”. (3) Method for measuring the effect of improving keratin (enhancing the exfoliative properties of keratinocytes) A scotch tape (Nichiban Mending Tape) was adhered to the skin of the test area before and after the start of the above-described measurement test for measuring rough skin, and after completion. When this was peeled off, the state of the keratinocytes attached to the tape was examined in detail by a scanning electron microscope,
The stratum corneum cell exfoliation was classified according to the criteria shown in Table 2 below, and the keratin improving effect was determined. [Table 2] Judgment is made when the difference between the evaluation point of the test site and that of the control site after continuous application for 4 weeks is 2 or more points is “valid”, 1 point or more is “slightly effective”, and 0 point is "Invalid". The test results were indicated by the number of subjects who became “effective” and “slightly effective”. (4) Sensory test (effect of beautiful skin) Female subjects complaining of rough skin, fine lines, dry skin, etc.
Test sample twice a day (morning and evening) for 20 persons 3
The coating was applied for 1 month, and the effect after 1, 2 and 3 months was evaluated.
In the test results, for each item of skin wettability, smoothness, and elasticity, the respondents answered that "skin was moistened", "skin became smooth", and "skin became taut" Indicated by the number of people. Examples 1 to 5 and Comparative Examples 1 to 6 (skin cream) (a) mevalonic acid, lactone mevalonate as component (b)
The components diisopropylamine dichloroacetate, urea, and lactic acid were blended as shown in Table 4, and each skin cream was prepared with the composition shown in Table 3, and the above-described experiments were performed. (1) Composition [Table 3] (2) Preparation method The component (A) in Table 3 was dissolved at 70 ° C, mixed with the component (B), and heated to 78 ° C. Next, this was gradually added to the component (C) heated to 75 ° C. with stirring to perform preliminary emulsification. Thereafter, the mixture was completely emulsified with a homogenizer, cooled to 50 ° C., added with the component (D), and cooled to 30 ° C. to prepare a skin cream. The R (-)-mevalonic acid lactone blended as the component (a) is considered to be present in the skin cream in an equilibrium state with R (-)-mevalonic acid. (3) Characteristics Various tests were carried out on each of the obtained skin creams,
The results are shown in Tables 4 and 5. [Table 4] [Table 5] As shown in Tables 4 and 5, the skin creams of Comparative Examples 1 to 6 containing no (a) component mevalonic acid and lactone mevalonate, and (b) component DADA, urea and lactic acid were used alone or separately. Although sufficient effects cannot be obtained in various properties, (a) mevalonic acid, mevalonate lactone,
(B) The skin creams of Examples 1 to 5 in combination with the components DADA, urea and lactic acid have the effects of improving rough skin, improving keratin, and increasing the turnover speed.
A remarkable effect was observed in the effect of preventing skin aging, and a sensory test also showed an effect of expressing and imparting wettability, smoothness, and elasticity two months after application. Example 6, Comparative Examples 7 to 9 (Skin Lotion) Each skin lotion was prepared according to the composition shown in Table 6 below, and various tests were carried out. (1) Composition [Table 6] (2) Preparation Method The components in Table 6 above were stirred and uniformly dissolved to prepare a skin lotion. (3) Characteristics The skin lotion of Example 6 exhibited excellent skin-cleaning effect and skin aging prevention effect (rough skin improvement effect, keratin improvement effect, and effect of increasing turnover speed) as compared with Comparative Examples 7 to 9. Example 7 (Skin cream) A skin cream was prepared according to the composition shown in Table 7 below. [Table 7] (2) Preparation method The components (A) and (B) shown in Table 7 were uniformly heated and dissolved to a temperature of 80 ° C. Next, after injecting and emulsifying the component (B) in the component (A), the mixture is stirred at 30 ° C.
And cooled to prepare a skin cream. Example 8 (Skin milk) Skin milk was prepared according to the composition shown in Table 8 below. (1) Composition Table 8 (2) Preparation Method The components (A) and (B) shown in Table 8 were uniformly heated and dissolved to adjust the temperature to 80 ° C. Next, after injecting and emulsifying the component (B) in the component (A), the mixture is stirred at 30 ° C.
And cooled to prepare a skin milk. The skin creams and skin milks obtained in Examples 7 and 8 exhibited excellent skin aging prevention effects (rough skin improvement effect, keratin improvement effect, effect of increasing turnover speed), and beautiful skin effect. . As described above, the present invention provides a skin aging preventive cosmetic which is excellent in skin aging prevention effect (rough skin improvement effect, keratin improvement effect, and effect of increasing turnover speed) and beautiful skin effect. It is clear to offer.

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Claims (1)

(57) [Claims 1] (a) 0.001 to 10% by weight of at least one selected from mevalonic acid and lactone mevalonate;
(B) diisopropylamine dichloroacetate, urea, one or more selected from the group consisting of lactic acid and its salts
0.001 to 3.0% by weight of a cosmetic composition for preventing skin aging.