JPH11302143A - Enhancer of barrier strength against permeation through skin, and cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an enhancer of a barrier strength against penetration through skin, capable of enhancing the barrier strength against the penetration through the skin, capable of protecting the inside of the skin from various stimulation, and further to obtain a cosmetic. SOLUTION: This enhancer of a barrier strength against penetration through skin contains carnitine chloride, and the cosmetic contains the enhancer. Each of the D-isomer, the L-isomer and the DL-isomer is usable as the carnitine chloride. The amount of the formulated carnitine chloride is 0.01-1.0 wt.% based on the whole amount of the enhancer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin permeation barrier strength enhancer which enhances the strength of a skin permeation barrier which protects the inside of skin from various adverse effects from the environment surrounding a living body.

[0002]

2. Description of the Related Art All living organisms including humans are affected by the surrounding environment. However, higher animals, such as mammals,
It has organs to minimize the environmental impact on each organ necessary to sustain life. It is the skin, and one of its most important functions is the epidermis permeation barrier function that prevents substances from entering the living body and preventing excessive evaporation of water from inside the living body.

[0003] The epidermis permeation barrier function is temporarily disintegrated by an organic solvent, a surfactant, ultraviolet rays or the like, and disturbs the environment inside the skin. Then, by repeating the disturbance of the environment inside the skin, phenomena such as exfoliation of corneocytes, wrinkles, bulges, and spots due to drying of the skin surface, which are general signs of skin aging, are observed. Moreover, if most of the epidermal penetration barrier function is lost, it becomes difficult to sustain life itself. Therefore, it is considered that enhancing the strength of the epidermal transmission barrier function is not only important for cosmetics but also important for maintaining life.

[0004] However, there has hitherto been no satisfactory reinforcing agent having an excellent effect of enhancing the skin permeation barrier strength.

[0005] It is an object of the present invention to provide a skin permeation barrier strength enhancer that enhances the skin permeation barrier strength that protects the inside of the skin from various stimuli, and a cosmetic.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above, and as a result, it has been found that the following skin permeation barrier strength enhancer is excellent in enhancing the skin permeation barrier strength. Was confirmed, and the present invention was completed.
That is, the object of the present invention is achieved by a skin permeation barrier strength enhancer containing carnitine chloride and a cosmetic containing the agent.

[0007]

Embodiments of the present invention will be described below in detail. Carnitine chloride used in the present invention is a known substance and has an action of increasing the secretory function of digestive juice, and is therefore applied as a pharmaceutical. Further, application as a skin cosmetic (Japanese Patent Application Laid-Open No. 51-148022) has also been proposed. However, the effect of enhancing the epidermal penetration barrier strength was not known at all and could not be analogized.

The carnitine chloride used in the present invention is a D-form,
Both the L-form and the DL-form (mixture) can be used, but as described below, the L-form or the DL-form is preferred from the viewpoint of the cell growth promoting effect on human keratinocytes, and the L-form is particularly preferred.

[0009] The amount of carnitine chloride of the present invention is from 0.01 to 0.01 based on the total amount of the epidermal penetration barrier strength enhancer.
1.0% by weight (hereinafter abbreviated as%) is preferred. If the amount is less than each of the lower limits, the intended effect of the present invention may not be sufficient, and if the amount exceeds the upper limit, the effect corresponding to the increase may not be improved, which is not preferable. .

[0010] The skin permeation barrier strength enhancer of the present invention can be applied to skin cosmetics, medicines, bath agents, etc., and in dosage form, for example, lotions, emulsions, creams, packs and the like. Can be applied. It should be noted that the skin permeation barrier strength enhancer of the present invention may contain, in addition to the above, dyes, fragrances, preservatives, surfactants, pigments, antioxidants, and the like, as long as the effects of the present invention are not impaired. it can. In addition, the cosmetic of the present invention includes skin cosmetics, hair nourishing cosmetics, hair cosmetics, bath additives and the like.

[0011]

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

Examples 1 to 5 and Comparative Example 1 The epidermal penetration barrier strength when the present invention was applied to aged skin was examined by the following test method (1).

Experimental Animals Used in Examples and Comparative Examples Five groups of hairless mice 85 weeks old at the start of the test were used.

(1) Skin Permeation Barrier Strength Measurement Test 1-1. Measurement apparatus and conditions The transepidermal water loss (hereinafter abbreviated as TEWL) was measured using a continuous perspiration measuring apparatus Hydrograph AMU-100 (manufactured by K & S Corporation) as follows. A 1 cm 2 capsule was brought into close contact with the skin, nitrogen gas was introduced into the capsule (300 ml / min), and the amount of water vapor in the nitrogen gas was measured before being sent to the capsule and after being recovered from the capsule. From the difference between the values, the amount of water (milligrams) evaporating from one square centimeter of skin per minute was calculated and defined as TEWL. 1-2. Sample and test method 0.5% polyoxyethylene nonylphenyl ether (NP-15; manufactured by Nikko Chemicals) aqueous solution (base)
In addition, carnitine chloride 0.001, 0.01, 0.1,
Samples containing 1.0 and 2.0% were prepared. First,
0.05 ml of this sample was previously applied to the back skin (about 2.5 cm in diameter) of a hairless mouse once a day, five times a week for four consecutive weeks (prior application). Then, on the third day from the final application of the pre-application, treatment was performed by gently wiping the back skin of the hairless mouse with a cotton swab soaked in acetone. At that time, the TEWL was measured every five wipes, the treatment was performed until the measured value became 0.15 mg / cm ² / min or more, the number of times was recorded, and the value was defined as the epidermal transmission barrier strength. If the number of treatments increases by applying the sample, it indicates that the epidermal transmission barrier strength is enhanced.

Table 1 shows the effect of the application of each sample on the strength of the epidermal transmission barrier of hairless mice.

[0016]

[Table 1]

From the results of this test, the coatings of Examples 1 to 5
It is apparent from the comparison with Comparative Example 1 that the epidermal transmission barrier strength was enhanced in a concentration-dependent manner. The particularly effective concentration was 0.01% or more, and it was found that the effect leveled off at 1.0% or more.

Examples 6 to 8 and Comparative Example 2 In this Example and Comparative Example, a skin lotion having the composition shown in Table 2 was prepared according to the following preparation method, and using it as a sample, the following procedure was used to prepare 10 healthy skin lotions. People (male, 24-5)
(3 years old) was applied to the skin on the inner side of the upper arm, and a human epidermal permeation barrier strength test (2) was performed by the following procedure.

(2) Human epidermis permeation barrier strength measurement test Each sample was administered once a day after application and at a frequency of seven times a week.
Test site (4cm ² , 2 × 2 for each sample)
cm). Next, on the third day from the end of the final application, using acetone, as in Examples 1 to 5,
The skin surface was wiped until the TEWL reached 0.15 mg / cm ² / min, and the number of treatments was recorded in units of five. In addition, the measuring device and conditions were the same as those of the above-mentioned 1-1.

Composition of skin lotion

[Table 2]

Preparation Method Carnitine chloride as the component C is blended with the component B, and after the components A and B are uniformly dissolved, the components A and B are mixed, stirred and dispersed, and then filled into a container. When used, the contents are shaken and dispersed uniformly.

Table 3 shows the effect on the human epidermal penetration barrier strength.

[0023]

[Table 3]

From the test results, it can be seen that the skin lotions of Examples 6 to 8 clearly enhance the skin permeation barrier strength as compared with Comparative Example 2. Further, no skin abnormality such as redness and dryness due to a skin lotion containing the epidermal permeability barrier strength enhancer according to the present invention was observed.

Examples 9 to 11 and Comparative Example 3 In the same manner as in Examples 6 to 8, skin creams having the compositions shown in Table 4 were prepared according to the following preparation method.
The human epidermal penetration barrier strength was examined.

[0026]

[Table 4]

Preparation Method Carnitine chloride as the component C is blended with the component B, and the components A and B are each heated and dissolved at 80 ° C., and then cooled to 30 ° C. while mixing and stirring to cool each skin cream. Prepared.

The permeation barrier strength of human epidermis was examined, and the results are shown in Table 5.

[0029]

[Table 5]

From the test results, it can be seen that the skin creams of Examples 9 to 11 clearly enhance the skin penetration barrier strength as compared with Comparative Example 3. In addition, skin abnormalities such as redness and dryness due to the skin cream containing the epidermal permeation barrier strength enhancer according to the present invention were not observed.

(3) Human epidermal cell proliferation test As a medium, MCDB153HAA (11.03 g /
l; manufactured by Wako Pure Chemical Industries, Ltd.)
(6.7 g / l; Dojin Chemical Co., Ltd.), BPE (4.0 m
l; manufactured by Kurabo Industries), NaHCO ₃ (1.2 g / l),
Insulin (5.0 mg / l; manufactured by Kanto Chemical Co.), E
GF (100 ng / l; SIGMA), hydrocortisone (180 μg / ml; MERCK), monoethanolamine (6.11 mg / l; Nacalai Tesque), phosphoethanolamine (14.11 mg /
l; manufactured by Tokyo Chemical Industry Co., Ltd.). Human normal epidermal keratinocytes (Casade Biologics)
Was adjusted to 1 × 10 ⁴ cells / ml in the above medium, and 1 ml was inoculated on a 24-well collagen coated plate (manufactured by Falcon), and 95% air (V / V) -5% (V / V) carbon dioxide gas And cultured at 37 ° C. for 4 days in an atmosphere of (One day after the culture, the culture supernatant was removed by suction, and
1 ml of a medium to which each sample was added except for GF and BPE (hereinafter referred to as medium 2) was added. After 3 days of culture, the culture supernatant was removed by suction, and then 1 ml of Medium 2 was added. ) 4
After culturing for one day, the number of viable cells was measured by trypan blue staining.

The results of the human epidermal cell proliferation test are shown in FIGS. The L-form and the DL-form showed a cell growth promoting effect at a specific concentration, whereas the D-form showed an inhibitory effect.

[0033]

As described above, the present invention can provide a skin permeation barrier strength enhancer excellent in enhancing the skin permeation barrier strength.

[Brief description of the drawings]

FIG. 1 is a graph showing the effect of DL-carnitine on promoting the proliferation of human epidermal keratinocytes.

FIG. 2 is a graph showing the effect of L-carnitine on promoting human epidermal keratinocyte proliferation.

FIG. 3 is a graph showing the inhibitory effect of D-carnitine on human keratinocyte proliferation.

Claims (3)

[Claims] 1. An epidermal penetration barrier strength enhancer comprising carnitine chloride. 2. The method of claim 1, wherein the carnitine chloride is L-carnitine chloride. 3. A cosmetic comprising the skin permeation barrier strength enhancer according to claim 2.