JPH1160432A - Skin cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a skin cosmetic capable of improving chapped skin, excellent in the use feeling and the excellent in the use feeling, while durably advancing and maintaining a water-retaining function of the skin by including a specific compound and urea. SOLUTION: This skin cosmetic comprises (A) about 0.01-50 wt.% cholesterol ester of an iso type fatty acid of formula I [(n) is 6-32] and/or an anti-iso type fatty acid of formula II, (B) about 0.01-20 wt.% urea, and optionally (C) about 0.01-30 wt.% sphingolipids and (D) an oil and fat, a coloring matter, a preservative, a surface active agent, a pigment, an antioxidant, a chelating agent, an ultraviolet absorption agent, an ultraviolet scattering agent, a polymer-based mucilaginous agent, saccharides, salts, a polyhydric alcohol, vitamins, amino acids or the like. The cosmetic can be applied to a (non)aqueous make-up cosmetic or basic cosmetic. Concretely, foundations, lipsticks, creams, milky lotions, packs, bathing agents or the like are cited as the cosmetic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin cosmetic applied to quasi-drugs, cosmetics and the like, and more particularly, to an effect of improving rough skin by continuously enhancing and maintaining the moisture retention function of the skin. And a novel skin cosmetic having excellent usability.

[0002]

2. Description of the Related Art Moisture of the skin always moves from the inside of the skin to the outer layer along a gradient of water content that decreases from the basal cell layer of the dermis to the stratum corneum of the epidermis and toward the outer layer. Has transpired. This water transpiration is controlled mainly by a defense function (barrier function) composed of a dense cell tissue in the stratum corneum, and the water transpiration (Trans)
epidermal Water Loss, TW
Abbreviated as L), for example healthy range 0.2~0.3mg / cm ² / hr in the forearm skin surface of the person in the normal condition of the skin, usually below about 0.25mg / cm ² / hr Is held. On the other hand, in the case of rough skin such as aging skin and dry skin, the TWL value shows the upper limit of the above range or a value larger than that depending on the degree, and the moisture retention function of the skin is reduced. Is recognized. 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.

[0003] Conventionally, sphingolipids, fatty acids, cholesterol, cholesterol esters, and the like have been used in anticipation of preventing a decrease in water retention function which is a factor of skin aging.
A method has been proposed in which a lipid component that is originally present in the stratum corneum and has a water retention function is applied to the skin (Japanese Patent Publication No. Hei 4-
No. 57641, JP-A-61-260008,
JP-A-62-29508). These lipid components, when applied to the skin, form a water-containing liquid crystal state on the skin, prevent water evaporation from the skin, improve water retention, and maintain normal skin function. .

[0004] However, when these lipid components are applied, the skin can be temporarily kept in a healthy state, but the persistence is poor, and the rough skin cannot be repaired.

[0005] Therefore, the present inventors characterized in that at least one selected from cholesterol esters of iso-type fatty acids and / or anteiso-type fatty acids and sphingolipids is an essential component for the purpose of enhancing the water retention function. (Japanese Patent Laid-Open No. 9-1)
No. 24456). However, although the effect of enhancing the water retention function is recognized, the effect of improving rough skin is not always sufficient.

[0006] On the other hand, urea is one of the natural moisturizing factors (NMF) components, which are considered to be very important for the moisture retention function of the skin. It has been widely used in quasi-drugs and cosmetics in anticipation of preventing rough skin and moisturizing function. However, conventional formulations containing urea alone or urea do not always provide sufficient moisture retention, and do not provide a sustained effect on improving rough skin.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a novel skin cosmetic which has an effect of improving rough skin and has excellent usability by continuously enhancing and maintaining the moisture retention function of the skin. With the goal.

[0008]

Means for Solving the Problems The present inventors have studied to solve the above-mentioned object, and as a result, have found that cholesterol esters of iso-type fatty acids represented by the following general formula (1) and / or the following general formula (2) It has been found that cholesterol esters of anteiso-type fatty acids represented by formula (1) and skin cosmetics containing urea as essential components achieve this object by their synergistic effect.

[0009]

Embedded image

(However, n is represented by 6 to 32.)

[0011]

Embedded image

(Where n is 6 to 32)

Further, when at least one selected from sphingolipids is further added to the above-mentioned constitution, the sphingolipids easily form a liquid crystal structure, and the effect of suppressing water evaporation due to the formed liquid crystal structure is further increased. It has been found that a significantly superior effect is exhibited for this purpose. That is, the present invention contains, as essential components, a cholesterol ester of an iso-fatty acid represented by the general formula (1) and / or a cholesterol ester of an ante-iso-fatty acid represented by the general formula (2), and urea. In skin cosmetics. Further, the present invention is a skin cosmetic comprising at least one selected from sphingolipids in addition to the above constitution.

[0014]

Embodiments of the present invention will be described below in detail.

The branched fatty acid cholesterol ester conventionally used as a raw material for cosmetics is composed of isostearic acid. This isostearic acid is mostly 2-heptylundecanoic acid, although the branch position and the branched alkyl chain length are not specified. On the other hand, the branched fatty acid cholesterol ester disclosed in the present invention is composed of iso-type and anteiso-type fatty acids. That is, it is limited to fatty acids having a methyl group at the 2-position from the terminal [the above-mentioned general formula (1)] and the 3-position from the terminal [the above-mentioned general formula (2)]. The branched fatty acid cholesterol ester of the present invention differs from the conventionally known branched fatty acid cholesterol ester 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. In addition, 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 these iso-type fatty acids and anteiso-type fatty acids has a low melting point and is in a range of forming a liquid crystal structure, that is, 6 to 32,
Preferably, the total number of carbon atoms is 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 anteiso-fatty acid, is present in the fetal epidermis of mammals such as humans. Can be used. It is also known that lanolin has a fatty acid or a cholesterol ester of a similar structure,
Those derived from this can also be used. Furthermore, those having these structures can also be obtained by esterifying 15-methylheptadecanoic acid (isoform),
These synthetic products can also be used.

The amount of the cholesterol ester of the iso- and / or ante-iso fatty acids of the present invention is about 0.01 to 50% by weight, based on the total amount of the final preparation.
(Hereinafter abbreviated as wt%).

Urea used in the present invention is a known compound, which is used not only as a humectant but also as a bactericide and a cell activator.

The amount of urea is preferably about 0.01 to 20% by weight based on the final preparation.

The sphingolipids used in the present invention include, in addition to ceramide, sphingolipids such as glucosylceramide, galactosylceramide, lactosylceramide and ganglioside; sphingolipids such as sphingomyelin, ceramide phosphoethanolamine and ceramide phosphorylglycerol. Can be mentioned. These sphingolipids can be obtained by extraction or synthesis from plants and animals, but the method of obtaining them is not limited thereto.

The amount of the sphingolipid is preferably about 0.01 to 30% by weight based on the final preparation.

In the skin cosmetic of the present invention, in addition to the essential components, fats and oils, pigments, fragrances, preservatives, surfactants,
Pigments, antioxidants, chelating agents, ultraviolet absorbers, ultraviolet scattering agents, polymeric adhesives, sugars, salts, polyhydric alcohols,
Appropriate amounts of vitamins, amino acids, and the like can be added as long as the object of the present invention is achieved.

The present invention is not particularly limited by the nature of the contents, and can be applied to aqueous or non-aqueous makeup cosmetics or basic cosmetics. For example, the makeup cosmetics include foundations, lipsticks and the like. Examples of the basic cosmetics include creams, emulsions, lotions, packs, bath agents and the like.

[0025]

The present invention will be described in detail below with reference to examples and comparative examples.

The method for extracting the fatty acid cholesterol ester mixture (derived from human vernix, derived from lanolin, synthetic method) according to the present invention is as follows.

Derived from human vernix The vernix was wiped off from the skin surface of a newborn baby immediately after childbirth using absorbent cotton, and vernix was extracted from the absorbent cotton 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, it was confirmed that this fraction contained about 40% of C14-26 isoform fatty acid cholesterol ester and about 20% of C15-C25 anteiso fatty acid cholesterol ester. The balance was unsaturated fatty acid cholesterol ester. These mixtures were subjected to the following examples.

Lanolin Derivative The present invention includes YOFCO CLE- manufactured by Nippon Seika Co., Ltd.
Although NH was used, it is not limited to this. YO
FCO CLE-NH is obtained by esterifying lanolin fatty acid obtained by saponifying wool fat with cholesterol by a known method. The composition contains about 35% of an iso-type fatty acid cholesterol ester having 12 to 30 carbon atoms and about 40% of an ante-iso-type fatty acid cholesterol ester having 11 to 31 carbon atoms, and the balance is a straight-chain type having 12 to 30 carbon atoms. It is a chain fatty acid cholesterol ester.

Synthetic product Commercially available 15-methylheptadecanoic acid (anteiso type) is reacted under a reduced pressure using a conventionally known method, that is, using a mineral acid such as p-toluenesulfonic acid as a catalyst, and subjected to silica gel column chromatography. Purification was performed by, for example, obtaining cholesterol ester of 15-methylheptadecanoic acid. These were subjected to the following examples.

Further, (1) rough skin improving effect test method, (2) stratum corneum improving effect test method, (3) moisturizing effect test method (TWL value reduction rate), (4) practical test (use) used in the present invention. Feeling) is as follows.

(1) Test Method for Improving Rough Skin Effectiveness The effect of continuous application for 4 weeks was examined on 20 middle-aged and elderly female subjects (35 to 55 years old) who complain of rough skin, dry skin, etc. on the lower leg. One day a day at the subject's left lower leg test site
About 1 g of the sample was applied to a 5 × 10 cm surface, and the skin condition before the start of the application and three days after the end of the application was visually determined according to the criteria for skin dryness shown in Table 1. The lower leg on the right side was used as a control without applying the sample.

[0032]

[Table 1]

The test results before and after the test are compared with those of the control site. If the degree of dryness of the skin is improved by two or more stages (for example, + → −, ++ → ±), the case where the skin dryness is improved by one stage is effective. Somewhat valid, no change if no change. The test results were indicated by the number of subjects who were effective or slightly effective.

(2) Stratum corneum improving effect test A scotch tape (Nichiban Mending Tape) is adhered to the subject's skin after the above-mentioned rough skin improving effect test is completed, and when this is peeled off, the state of the keratinous cells adhered to the tape is scanned. The cells were examined in detail by a scanning electron microscope, and the anti-peeling properties of the skin keratinocytes were analyzed according to the criteria shown in Table 2, and the effect of improving the stratum corneum (the effect of increasing the anti-peeling properties of keratinocytes) was determined.

[0035]

[Table 2]

The evaluation is effective when the difference between the evaluation point of the test site and that of the control site on the third day after the end of the continuous application for 4 weeks is 2 or more points, 1 point is slightly effective, and 0 point. Was invalidated. The test results were expressed as the number of subjects who were effective or slightly effective among 20 subjects.

(3) Moisturizing Effect Test (TWL Value Reduction Rate) The skin of the subject before and after the start of the above-mentioned rough skin improving effect test was targeted. Before 4 consecutive weeks of application and on the 3rd day after the end of the application, TWL values were measured, and the TWL value reduction rate (water retention function enhancement effect) was calculated from these values as follows.
The moisturizing effect was examined.

(Measurement method of TWL value) A method was used in which a change in humidity of air on a closed skin surface within a predetermined time was converted into electric resistance and measured. 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. The relative humidity RHs (%) is obtained, and then left for 10 minutes, and the relative humidity RH10 in the cell is again measured.
(%) Was measured, and a 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 )

(TWL value reduction rate) The TWL value reduction rate was calculated by substituting the TWL values before and after the sample application, TWLA and TWLB into the following equation. TWL value reduction rate (%) = (1−TWLB / TWLA) ×
100 TWLA: TWL value before sample application TWLB: TWL value on the third day after sample application is completed “valid” when the reduction rate of TWL value is 20% or more, and “invalid” when the reduction rate is less than 20% did. The test results are
The number is indicated by the number of subjects who were “effective” out of 20 subjects.

(4) Practical Test (Feeling of Use) The effect of the above-mentioned rough skin improvement effect test on the third day after completion 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 8 and Comparative Examples 1 to 8 (Skin Cream) Each skin cream having the composition shown in Table 3 was prepared and used as a sample.

(1) Composition

[0043]

[Table 3]

Tables 4 and 5 show the ingredients of the present invention incorporated in the skin cream.

[0045]

[Table 4]

[0046]

[Table 5]

(2) Preparation method The components (C) and (E) were added to the component (A), and dissolved by heating at 80 ° C., and then dissolved in advance by heating to 80 ° C. (B) and (B). D) The components were added, mixed, and dispersed with a homomixer. Next, each skin cream was prepared by cooling to 30 ° C. while stirring.

(3) Characteristics Table 6 shows the results of the above-mentioned tests performed on the skin creams of Examples 1 to 8 and Comparative Examples 1 to 8.

[0049]

[Table 6]

From Table 6, it can be seen that the skin creams of Examples 1 to 8 of the present invention do not satisfy the essential conditions of the present invention.
Compared to the skin cream of No. 8, all the properties were excellent. In each of the examples, no abnormality was recognized in the compounding characteristics. In addition, Examples 4-8 are Examples 1-8.
In this example, sphingolipids were further added to the component No. 3, and as a result, the test items of Examples 4 to 8 are described, and a synergistic effect due to the addition of sphingolipids is recognized.

Examples 9 to 14 and Comparative Examples 9 to 14 (Essences) Each of the compositions shown in Table 7 was prepared and used as a sample.

(1) Composition

[0053]

[Table 7]

Table 8 shows the components of the present invention mixed in the serum.
It is shown in FIG.

[0055]

[Table 8]

[0056]

[Table 9]

(2) Preparation method Components (C) and (E) were added to component (A), and dissolved by heating at 80 ° C., and then dissolved by heating at 80 ° C. in advance (B) and (B). D) The components were added, mixed, and dispersed with a homomixer. Next, each essence was prepared by cooling to 30 ° C. while stirring.

(3) Characteristics Table 10 shows the results of the above-mentioned tests performed on the essences of Examples 9 to 14 and Comparative Examples 9 to 14.

[0059]

[Table 10]

In comparison with the essences of Comparative Examples 9 to 14 which did not satisfy the essential conditions of the present invention, the essences of the present invention of Examples 9 to 14 showed good results over all of the tests. . In each of the examples, no abnormality was recognized in the compounding characteristics. Examples 12 to 14 correspond to examples 9-1.
This is an example in which sphingolipids are further added to the constituent component 1. As a result, Examples 12 to 14 show the test items, and a synergistic effect due to the addition of sphingolipids is recognized.

Example 15, Comparative Example 15 (Bath agent) The bath agent composition of Example 15 was prepared by a conventional method, and
20 g of the bath composition was placed in 1 liter of hot water. "Moist skin" 12 hours after bathing with 20 panelists
-"Smooth skin feeling" was tested by comparison with the bath preparation composition of Comparative Example 13 similarly prepared. Table 11 shows the compositions of Example 15 and Comparative Example 15 and the number of subjects who answered "effective" or "good" by the paired comparative evaluation method, respectively.

[0062]

[Table 11]

From Table 11, it was found that the bath preparation of Example 15 had better results over all the tests than the bath preparation of Comparative Example 15 which did not satisfy the essential conditions of the present invention.
In each of the examples, no abnormality was recognized in the compounding characteristics.

[0064]

As described above, the skin cosmetic of the present invention has a high effect of continuously increasing and maintaining the moisture retention function of the skin, has a synergistic effect of improving rough skin, and has a feeling of use. Clearly, it provides an excellent skin cosmetic.

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[Procedure amendment]

[Submission date] October 20, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

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. These branched fatty acid cholesterol ester may be a mixture with other fatty acid cholesterol ester, or may consist solely of branched fatty acid cholesterol ester. The total number of carbon atoms of these iso-type fatty acids and anteiso-type fatty acids has a low melting point and is in a range for forming a liquid crystal structure, and is 10 to 37 , preferably 12 to 28 in total.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kunio Mimura 5-28, Kotobukicho, Odawara City, Kanagawa Prefecture Kanebo Co., Ltd.

Claims (2)

[Claims] 1. A compound of the general formula (1) (Where n is 6 to 32) cholesterol ester of iso-fatty acid and / or general formula (2) (Where n is 6 to 32) A skin cosmetic comprising cholesterol esters of anteiso-type fatty acids represented by the formula: and urea as essential components. 2. The skin cosmetic according to claim 1, further comprising sphingolipids.