JPH10175843A - Cosmetic for skin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain cosmetics for skin, consisting essentially of a specific cholesterol ester and vitamin E (derivative) and having improving activities of an aged skin such as improving activities on a roughened skin, advancing activities of water-retaining function and activities for making the skin beautiful. SOLUTION: The objective cosmetics consist essentially of (A) a cholesterol ester of an iso form and/or anti-iso form fatty acid of formulas I [(n) is 6-32] and II, and (B) vitamin E and/or vitamin E derivative (e.g. an acetate). The iso form and/or anti-iso form fatty acid derived from a mammal lanolin or vernix caseosa can be used as the iso form and/or anti-iso form fatty acid. The formulating amount of the component A is preferably 0.01-50wt.% and that of the component B is preferably 0.001-10.0wt.% based on the whole amount of the final preparation. The formulation ratio of the components A to B is preferably (0.01:1) to (100:1). The cosmetics can optionally includes sphingolipids, phospholipids, sterols and steroids other than the essential component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a skin cosmetic which is applied to quasi-drugs, cosmetics, etc., and has excellent aging skin improving effects (rough skin improving effect, moisture retaining function enhancing effect, beautiful skin effect, etc.).

[0002]

BACKGROUND OF THE INVENTION Aged skin loses its flexibility and elasticity, has increased skin wrinkles, and has a dry, non-smooth, rough skin condition. This is considered to be due to a decrease in the water retention function and barrier function of the stratum corneum, a decrease in sebum secretion, and the like.

[0003] The state of rough skin due to aging is determined by the transepidermal water loss (Transepidermal Water L).
oss (hereinafter abbreviated as TWL). That is, the water in the skin always moves from the inside of the skin to the outer layer along the gradient of the water content decreasing from the basal cell layer of the dermis to the stratum corneum of the epidermis toward the outer layer, and evaporates to the outside through the stratum corneum. ing. This T
WL is controlled mainly by a protective function (barrier function) composed of a dense cell tissue of the stratum corneum. The TWL value is, for example, 0.2 to 0.2 in a human forearm skin surface in a normal state of healthy skin. It is kept in the range of 0.3 mg / cm ² / hr, usually about 0.25 mg / cm ² / hr or less. On the other hand, in the case of rough skin seen in aged skin, the TWL value shows the upper limit of the above range or a value larger than that, depending on the degree thereof, and it is recognized that the moisture retention function of the skin is reduced. In the case of these rough skins, it is due to a state where the normal control limit by the protective function of the stratum corneum has been exceeded or the protective function has deteriorated.

[0004] On the other hand, collagen and elastin are components that form most of the structure of the skin, and are said to affect the elasticity and flexibility of the skin. It is believed that aging decreases these soluble fractions, forms crosslinked structures, and reduces elasticity and flexibility. In addition, the metabolism of collagen decreases with aging, and hyaluronic acid, which is an intercellular substance of the skin, is significantly reduced, leading to a decrease in the water content of the skin. As a result, the aged skin is totally atrophied and non-thinned, loses its flexibility, elasticity and smoothness, and becomes rough skin.

[0005] Vitamin E and its derivatives, which are said to be effective for skin eczema, inflammation and wrinkles, are expected to improve such aging skin.
It has been used for protective agents and skin cosmetics (JP-A-61
-40210). However, in practical use, even when these skin cosmetics containing vitamin Es are applied to the skin, the skin function is restored or improved, the function originally possessed by the skin is restored, and the effect of preventing skin aging is remarkably improved. It was not enough to show the effect.

[0006] In addition, with the expectation of preventing a decrease in the water retention function, which is one of the factors of skin aging, conventionally, sphingolipids, fatty acids, cholesterol, cholesterol esters and the like originally exist in the stratum corneum, A method has been proposed in which a lipid component responsible for the above is applied to the skin (Japanese Patent Publication No. 4-57641, Japanese Patent Application Laid-Open No. 61-2600).
08, JP-A-62-29508). Furthermore, among cholesterol esters, it has been proposed that cholesterol esters of iso-fatty acids and / or anteiso-fatty acids have a high effect of enhancing the water retention function of the stratum corneum (JP-A-60-199809).

However, by simply supplementing the lipids originally present in the stratum corneum, the skin can be kept in a healthy state temporarily, but a sustained and sufficient effect of enhancing the water retention function can be obtained. Did not.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a skin cosmetic composition having a high aging skin improving effect, which eliminates the insufficient aging skin improving effect of conventional products.

[0009]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies in view of the above-mentioned circumstances, and as a result, have found that isoform fatty acids represented by the general formulas (1) and (2) and / or Alternatively, it has been found that a skin cosmetic containing cholesterol ester of anteiso fatty acid and vitamin E and / or a vitamin E derivative as essential components can achieve the object.

[0010]

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(Where n is 6 to 32)

[0012]

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(However, n is represented by 6 to 32)

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail.

[0016] Isostearic acid, which has been conventionally used as a raw material for cosmetics, does not specify the branch position and the branched alkyl chain length, but most means 2-heptylundecanoic acid. On the other hand, isoforms disclosed in the present invention,
The anteiso-type fatty acids are respectively 2-position from the terminal [the above-mentioned general formula (1)] and 3-position from the terminal [the above-mentioned general formula (2)]
Limited to fatty acids having a methyl group. The present invention differs from conventionally known raw materials in that the branch position and the branched alkyl chain length are specified.

The branched fatty acid cholesterol ester used in the present invention does not need to be separated into an iso form and an ante iso form, but may be used separately. Further, these branched fatty acid cholesterol esters may be a mixture with other fatty acid cholesterol esters, or may be composed of only branched fatty acid cholesterol esters. The total carbon number of the iso fatty acid and the anteiso fatty acid is preferably from 10 to 32, more preferably from 12 to 28.

The fatty acid cholesterol ester mixture used in the present invention, which is characterized by containing a cholesterol ester of an iso fatty acid and / or an ante iso fatty acid, is present in the fetal epidermis of mammals such as humans. Can be used.
It is also known that lanolin contains a fatty acid or a cholesterol ester thereof having a similar structure, and those derived therefrom can also be used. Furthermore, those having these structures can be obtained by a method such as esterification of 15-methylheptadecanoic acid (isoform), and these synthetic products can also be used.

The vitamin E and / or a derivative thereof used in the present invention are known substances, for example, vitamin E, vitamin E acetate, vitamin E nicotinate,
Vitamin E succinate, vitamin E orotate and the like can be mentioned. Vitamin E refers to α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, and the like, or a mixture thereof. In the present invention, these vitamin Es are used alone or as a mixture with a derivative thereof.

The compounding amount of the cholesterol ester of the iso-fatty acid and / or the anteiso-fatty acid of the present invention is as follows:
It is preferably 0.01 to 50.0% by weight (hereinafter abbreviated as wt%) based on the total amount of the final preparation. The blending amount of vitamin E and / or its derivative is preferably 0.001 to 10.0 wt% based on the total amount of the final preparation. The mixing ratio of the fatty acid cholesterol ester mixture of the present invention to vitamin E and / or a derivative thereof is 0.0
A ratio of 1: 1 to 100: 1 is preferred.

In order to further improve the effects of the present invention,
In addition to the essential components, sphingolipids, phospholipids, sterols, and steroids can be appropriately added to the skin cosmetic of the present invention as long as the present invention is achieved.

The skin cosmetic of the present invention may optionally contain oils and fats, pigments, fragrances, preservatives, surfactants, pigments, antioxidants, etc., as needed, within the range of achieving the object of the present invention. Can be.

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

[0024]

Embodiments will be described below. The fatty acid cholesterol ester mixture used in the examples was obtained by the following method.

(Derived from human vernix) Vernix was wiped off from the skin surface of a newborn baby immediately after childbirth using gauze, and vernix was extracted from the gauze with chloroform: methanol (2: 1). A fatty acid cholesterol ester fraction was obtained from the obtained vernix by silica gel column chromatography using hexane and benzene as a developing solvent. By gas chromatography, this fraction contained 14 to 14 carbon atoms.
26 isoform fatty acid cholesterol esters of about 40
%, Containing about 20% of an anteiso-type fatty acid cholesterol ester having 15 to 25 carbon atoms.
The balance was unsaturated fatty acid cholesterol ester.
These mixtures were subjected to the following examples.

(Derived from lanolin) YOF of Nippon Seika Co., Ltd.
CO CLE-NH was used. YOFCO CLE-N
H is obtained by esterifying lanolin fatty acid obtained by saponifying and decomposing wool fat with cholesterol according to a conventional method. Further, the composition contains about 35% of an iso-type fatty acid cholesterol ester having 12 to 30 carbon atoms and about 40% of an anteiso-type fatty acid cholesterol ester having 11 to 31 carbon atoms, and the balance is 12 to 30 carbon atoms.
Is a straight chain fatty acid cholesterol ester.

(Synthetic product) Commercially available 15-methylheptadecanoic acid (anteiso type) was esterified with cholesterol according to a conventional method to obtain cholesterol ester of 15-methylheptadecanoic acid.

Further, (1) a rough skin improvement effect test, (2) a moisturizing effect test (TWL value reduction rate), and (3) a beautiful skin effect used for evaluating the skin aging prevention effect of the skin cosmetic composition of the present invention. The test (practical test) is as follows.

(1) Test for Improvement of Rough Skin The effect of continuous application for four weeks was examined on 20 middle-aged and elderly subjects with rough skin on the lower leg. Approximately 1 g of a sample was applied to the left lower leg test site of the test subject once a day, and the condition of the skin before and after the test was visually determined according to the criteria shown in Table 1. The lower leg on the right side was used as a control without applying the sample.

[0030]

[Table 1]

By comparing the judgment results of the test site and the control site before and after the test, when the degree of dryness of the skin is improved by two or more stages (for example, + → −, ++ → ±), “effective” is improved by one stage. "Slightly valid" for cases, "Disabled" for no change
And The test results were indicated by the number of subjects who became “effective” and “slightly effective”.

(2) Moisturizing Effect Test (TWL Value Reduction Rate) The TWL values before and after the continuous application for 4 weeks in the test subject skin before and after the start of the rough skin improvement effect test were determined. The reduction rate (water retention function enhancement effect) was calculated as follows, and the moisture retention effect was examined.

(Measurement method of TWL value) A method of measuring a temperature change of air on a closed skin surface within a predetermined time by electric resistance was used. That is, the skin of the subject is sealed with the measuring cell, forced air is passed through the cell to sufficiently replace the inside of the cell with dry air, and then the ventilation of the dry air is stopped and the inside of the cell at that time is stopped. Determine the relative humidity RHs (%), then
After leaving for 0 minutes, the relative humidity RH10 (%) in the cell was measured again, and the TWL value (mg / cm ² / hr) was calculated from the change in humidity at this time by the following equation. TWL value = [(RH10−RHs) × Dt × V × 6] /
(S × 100) where Dt: density of saturated water vapor in air at measurement temperature (t ° C.) mg / l) V: cell volume (l) S: measurement area (cm ² )

(Reduction rate of TWL value) The reduction rate of the TWL value is determined by the TWL values before and after the sample application, twla and twlb.
Was calculated by substituting into the following equation. TWL value reduction rate (%) = (1−TWLB / TWLA) ×
100, where TWLA: TWL value before sample application TWLB: TWL value after sample application The case where the reduction rate of the TWL value is 20% or more is “valid”, and the case where the reduction rate is less than 20% is “invalid”. Sample results are
The number was shown as the number of subjects who were “valid” out of 20 subjects.

(3) Beautiful skin effect test (practical test) Female subjects complaining of rough skin, fine wrinkles, dry skin, etc. (35-5
The effect of using the sample twice a day (morning / evening) for three consecutive months was evaluated for 20 persons (5 years old). 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 4 and Comparative Examples 1 to 5 (Skin Cream) Skin creams were prepared according to the compositions shown in Table 2, and the above-mentioned tests were carried out.

(1) Composition

[0038]

[Table 2]

Table 3 shows the ingredients of the present invention incorporated into the skin cream.

[0040]

[Table 3]

(2) Preparation method Components (C) and (D) are added to component (A),
After heating and dissolving, the component (B) previously heated and dissolved at 80 ° C. was added, mixed and stirred, and further emulsified using a homomixer. Next, each skin cream was prepared by cooling to 30 ° C. while stirring.

(3) Characteristics The tests described above were carried out for Examples 1-4 and Comparative Examples 1-5. The results are shown in Table 6 below.

Examples 5 to 8, Comparative Examples 6 to 8 (Serum) Serum was prepared according to the composition shown in Table 4, and the above-mentioned tests were carried out.

(1) Composition

[0045]

[Table 4]

Table 5 shows the components of the present invention mixed in the serum.

[0047]

[Table 5]

(2) Preparation method Components (C) and (D) are added to component (A),
And added to the component (B) which had been heated to 80 ° C. in advance, mixed, and dispersed with a homomixer. Then
Each essence was prepared by cooling to 30 ° C. while stirring.

(3) Characteristics The tests described above were carried out for Examples 5 to 8 and Comparative Examples 6 to 8. Table 6 shows the results.

[0050]

[Table 6]

As shown in Table 6, the skin creams of Examples 1 to 4, which are the skin cosmetics of the present invention, were the cosmetics containing no mixture of fatty acid cholesterol ester and the vitamin Es of Comparative Example 1, and the fatty acids of Comparative Example 2. Cholesterol ester mixture-free cosmetic, Comparative Example 3 vitamin E-free cosmetic, Comparative Example 4 straight-chain fatty acid cholesterol ester-containing cosmetic, Comparative Example 5 branching position / branched alkyl chain length different from that of the present invention Compared to cholesterol ester-containing cosmetics, they were excellent in all of their properties. Also,
In each of the examples, no abnormality was observed in the compounding characteristics. Furthermore, the cosmetics of Examples 5 to 8, which are the skin cosmetics of the present invention, are the cosmetics without the fatty acid cholesterol ester mixture of Comparative Example 6, the cosmetics without the vitamin Es of Comparative Example 7, and the cosmetics of Comparative Example 8. Good results were observed over all of the tests as compared with the cosmetics containing the saturated fatty acid cholesterol ester.

[0052]

As described above, the skin cosmetic of the present invention improves or repairs the skin to a healthy state by enhancing and maintaining the water retention function inherent to the skin, and aging the skin. It is clear that it provides an excellent skin cosmetic having an improving effect.

Claims (3)

[Claims] 1. A compound of the general formula (1) (Where n is 6 to 32) and the general formula (2) (Where n is from 6 to 32) skin cosmetics comprising, as essential components, a cholesterol ester of an iso-form fatty acid and / or anteiso-form fatty acid, and vitamin E and / or a derivative thereof. Fees. 2. The skin cosmetic according to claim 1, wherein the iso fatty acid and / or the anteiso fatty acid is a cholesterol ester derived from lanolin. 3. The skin cosmetic according to claim 1, wherein the cholesterol ester of an iso-fatty acid and / or anteiso-fatty acid is derived from mammalian vernix.