JPS62226910A - Skin cosmetic - Google Patents

Abstract

PURPOSE:A skin cosmetic which has improved stability with time free from side effects and skin irritation and can simultaneously develop and provide preventing effects on chapped skin and skin aging and beautifying effects, obtained by blending a skin cosmetic with a 2-O-alkyl L-ascorbic acid. CONSTITUTION:A skin cosmetic having an ordinary dosage form such as cream, milky lotion, lotion, powder, etc., is blended with usually 0.05-10wt%, preferably 0.5-3wt% based on total amount of prescription components of the cosmetic of at least one 2-O-alkyl L-ascorbic acid shown by formula (R is 10-22C alkyl). Consequently, a skin cosmetic which is stable and causes no change in color, no change in smell, no reduction activity, etc., even by long-term preservation, has no skin irritation in use, beautifies the body while providing an improved feeling, increases charm, keeps the skin healthy and can simultaneously develop and provide preventing effect on skin aging and beautifying effects is obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a skin cosmetic containing a specific ascorbic acid derivative described below, and more specifically, it has no undesirable side effects or skin irritation on the human body, and has a long-term use. The present invention relates to a skin cosmetic that is stable even when stored and can simultaneously exhibit and impart excellent skin roughness prevention effects, skin aging prevention effects, and excellent skin whitening effects.

(Prior Art) Aging skin loses its flexibility and elasticity, wrinkles increase, and the skin becomes dry and rough without smoothness, and a phenomenon of exfoliation of keratin cells is observed.

Recently, a few cosmetics have been proposed for preventing skin aging, but none have been found to have sufficient effects.

On the other hand, in order to restore sunburned skin to a healthy complexion, it is said that it is necessary to lighten the increasing amount of melanin pigment formed and inhibit tyrosinase activity during the melanin production process.

As an active substance for whitening cosmetics that apply these principles,
Several ascorbic acid derivatives have been researched, and 8-mono-di-butyrate fatty acid esters and 2,6-di-di-diylene fatty acid esters of ascorbic acid have been proposed (Japanese Patent Publication No. 45-16
No. 891, Special Publication No. 46-28684). However, when applied to cosmetics, there are drawbacks such as problems with oral stability, causing discoloration and odor, and failure to obtain excellent whitening effects.

As described above, an excellent skin cosmetic that can exhibit and provide skin anti-aging effects and whitening effects has not yet been found.

(Problems to be Solved by the Invention) The object of the present invention is to be stable even when stored for a long period of time, and to prevent discoloration and odor.
An excellent product that can beautify the body, increase attractiveness, keep the skin healthy, and simultaneously express and impart skin anti-aging effects and whitening effects while giving a good feel without causing skin irritation, without causing a decrease in activity, etc. The purpose of the present invention is to provide skin cosmetics with improved skin care.

(Means for solving the problem) The above-mentioned object contains at least one of 2-0-alkyl L-ascorbic acids represented by (wherein R is an alkyl group having 10 to 22 carbon atoms) This is achieved by a skin cosmetic product characterized by the following.

The 2-0-alkyl-ascorbic acid used in the present invention is a known substance. - Obtained by subjecting benzy-2-0-alkyl ascorbic acid to a catalytic reduction reaction.

Examples of the 2-0-alkyl-ascorbic acid represented by the above general formula include 2-0-decyl L-ascorbic acid, 2-o-undecyl L-7scorbin+*, and 2-0-decyl L-ascorbic acid.
o-dodecyl L-ascorbic acid, 2-0-)lysosyl L-ascorbic acid.

2-0-tetradecyl L-ascorbic acid, 2-0-pentadecyl L-ascorbic acid, 2-0-hexadecyl L-ascorbic acid, 2-0-heptadecyl L-ascorbic acid, 2-o-octadecyl L-ascorbic acid,
2-0-nonadecyl L-ascorbin 1, 2-0-eicosyl L-ascorbin 9.2-0-heneicosyl L-
Examples include ascorbic M, 2-0-tocosyl L-7 scorbic acid, and the like.

In the present invention, the above-mentioned 2-0-alkyl-ascorbic acids are blended into the skin cosmetic base either singly or as a mixture of two or more thereof.

The amount to be blended varies depending on the form H (type) of the skin cosmetic, but the overall amount to be blended is usually 0.05 to 10% by weight, preferably 0.05 to 10% by weight, based on the total amount of prescription ingredients of the cosmetic. is within the range of 0°5 to 8 double star Chi.

The dosage form of the skin cosmetic of the present invention is not particularly limited, and may be cream, emulsion, or lotion.

Usual cosmetic formulations such as powder form can be applied.

The cosmetic of the present invention includes an emulsifier as another component.

Oily substances, humectants, perfumes, preservatives, coloring agents, skin nutrients, and the like may be incorporated as appropriate within the scope of achieving the object of the present invention.

(Effects of the invention) The skin cosmetics of the present invention are stable even after long-term storage, and do not cause discoloration.
It does not cause odor or decrease in activity, and when used, gives a good feel without irritating the skin while beautifying the body, increasing attractiveness, keeping the skin healthy, and simultaneously exhibiting and imparting skin anti-aging effects and whitening effects. It is possible.

(Function) The 2-0-alkyl L-ascorbic acid of the present invention has particularly high stability in a cosmetic system, and also has high compatibility with cosmetic base materials, emulsifying properties, and safety for the human body. , it is possible to easily design a formulation for a skin cosmetic, and it is possible to provide a cosmetic that has good oral stability and provides a good feeling without irritating the skin.

Examples will be described below.

In addition, "excellent" shown in Examples means a weight of 11%.

Method for measuring turnover rate of stratum corneum described in Examples,
Sensory effect panel test, whitening effect panel test, skin) 1: Recovery test method is as follows.

(1) Method for measuring the turnover rate of the stratum corneum An ointment containing 5 parts by weight of the fluorescent dye danzyl chloride in white petrolatum was prepared and applied to the skin of the subject's forearm for 24 hours, and the ointment was applied to the skin of the forearm of the subject. Osmotic binding of danzyl chloride.

Thereafter, the test sample was applied to the same area twice a day (morning and evening), and the fluorescence of danzyl chloride was examined every day.The number of days until the fluorescence disappeared was defined as the turnover rate of the skin stratum corneum. Note that the turnover rate of the normal skin stratum corneum is 14 to 16 days, but in aged skin it is 18 days.
It grows around the day. On the other hand, once the anti-aging effect appears, the time is shortened to around 12 days. This time, the test was conducted on 5 subjects, and the average value was calculated.

(2) Sensory effect panel test: Samples were applied to the faces of 20 middle-aged (80-50 years old) female panelists twice a day for 2 months, and each panelist tested the test before and after the test. The skin condition was evaluated for "wrinkle smoothing effect,""effect on firmness," and "effect on first texture."

(3) Panel test of skin whitening effect Samples were applied to a panel of 20 test subjects (female) suffering from sunburn, once every morning and evening for two months.
Panera himself judged either "effective" or "ineffective."

(4) Skin color brightness recovery test The back skin of 20 test subjects was irradiated with ultraviolet rays in the UV-B region at twice the minimum amount of erythema, and after one week, the irradiated areas were covered with sample application areas and unapplied areas. The reference brightness (Vo value, vo' value) of each skin was measured. Subsequently, the sample was continuously applied to the application site once a day for 8 months, and the skin brightness (Vn...
・value, vn'... value) was measured, and skin color recovery evaluation was performed according to the criteria shown in Table 1.

In addition, the brightness of the skin (V value) was calculated from the Munsell value obtained by measurement with a high-speed spectral colorimeter d[. Moreover, the evaluation was shown as the average value of the evaluation scores of 20 test subjects after 18 weeks.

Table 1 (5) Storage stability test (stability of cosmetics after 6 months at 40°C) Appearance changes (separation, discoloration, etc.) after storing cosmetic samples in a constant temperature room at 40°C for 6 months Eight specialized inspectors examined the presence or absence of odor, etc.) and the presence or absence of strange odors.

Examples 1 to 6, Comparative Examples 1 to 4 [Skin Cream] Skin creams as Examples and Comparative Examples were prepared by changing the derivative of 7-scorbic acid in the following composition as shown in Tables 2 and 8. We prepared and conducted various tests. The second result is
．． It is shown in Table 8.

Composition Examples 6 to 9, Comparative Example 5 [Two-layered low-density] Similar to Example 1, the following compositions were used as examples,
A comparative example of two-layer ROSHI M was prepared and various tests were carried out. The results are shown in Table 4.

Assembling

Claims (1)

[Claims] (1) Contains at least one of 2-O-alkyl L-ascorbic acid represented by the following general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (wherein R is an alkyl group having 10 to 22 carbon atoms) A skin cosmetic product characterized by: