KR101196096B1 - Method for stabilizing alpha-lipoic acid - Google Patents

Abstract

PURPOSE: A cosmetic composition containing stabilized alpha-lipoic acid is provided to enhance skin whitening function. CONSTITUTION: A method for stabilizing alpha-lipoic acid comprises: a step of putting hydroxypropyl beta-cyclodextrin to water as a solvent and heating at 60-80 Deg. C.; a step of putting alpha-lipoic acid to the mixture and mixing at 50-60 Deg. C.; a step of adding Tremella Fuciformis extract to the mixture; and a step of adjusting pH of the mixture by 7.0-9.0. [Reference numerals] (AA) Embodiment 3 cosmetic composition; (BB) Initial phase; (CC) 2 weeks; (DD) 4 weeks; (EE) 8 weeks; (FF) 12 weeks

Description

Method for stabilizing alpha lipoic acid {Method for stabilizing alpha-lipoic acid}

The present invention relates to a technique for stabilizing alpha lipoic acid to be used in cosmetics, and a technique for effectively using alpha lipoic acid having antioxidant activity and skin lightening activity.

Alpha lipoic acid (Thioctic acid, alpha lipoic acid, α-Lipoic acid) is an ingredient that is attracting attention as an antioxidant, exfoliant, anti-inflammatory agent, and has been widely used in the food field for a long time. It was first discovered as an antioxidant in 1951 and acts as an essential coenzyme to break down carbohydrates in vivo. It is an antioxidant that acts on both the water-soluble and fat-soluble properties of cells and is called a broad spectrum antioxidant.

Thioctic acid (Thioctic acid, Alpha Lipoic acid, α-Lipoic acid) has a chemical structure with 8 carbons and 2 sulfurs. Is converted to). The application of 3% lipoic acid is said to reduce the erythema caused by ultraviolet B by half than by applying only lecithin, and further reduce skin damage, photoaging and cancer caused by free radicals.

However, alpha lipoic acid is relatively stable in a solid state, but is heated to a melting point (47.5 ° C.) or difficult to use because it quickly becomes a rubbery or dendritic polymer in an aqueous state. Accordingly, studies to stabilize this have been conducted.

Korean Patent Registration No. 0760148 describes a cosmetic composition comprising alpha-lipoic acid, which is a propylene glycol, glycerin, 1,3-butylene glycol, 1,3-butanediol and sorbitol based on the total weight of the composition as a stabilizer of alpha-lipoic acid. 0.1-30% by weight of one or more polyols selected from the group consisting of POE (polyoxyethylene) sorbitan fatty acid esters, POE alkyl ethers (LA), POE hydrogenated ester oils, POE (10) octyldodecyl ethers, POE (15) octyldodecyl ether, POE (20) octyldodecyl ether, POE (30) octyldodecyl ether, POE (15) glyceryl monostearate, POE (20) glyceryl monostearate, POE (25) A cosmetic composition comprising 0.01 to 10% by weight of at least one nonionic surfactant selected from the group consisting of glyceryl monostearate and POE (30) glyceryl monostearate is disclosed. Hanminguk Patent Publication No. 2009-0009217, the alpha-lipoic acid (alpha lipoic acid) 0.1 ~ 20.0% by weight; 0.1 to 12% by weight of one or more amino acids; 0.5-25.0 wt% of one or more water-insoluble polymers having self-emulsifying properties; And water, hydrophilic solvents or mixtures thereof as residuals.

The present inventors contribute to the stabilization of alpha lipoic acid when synthesizing the alpha lipoic acid when using the extract of natural white mushrooms when the alpha lipoic acid is included in the study while stabilizing the alpha lipoic acid, and the cosmetics by synergism The present invention has been found to improve the whitening activity of.

It is an object of the present invention to provide a cosmetic composition comprising stabilized alpha lipoic acid.

It is another object of the present invention to provide a method for preparing a cosmetic composition containing the stabilized alpha lipoic acid.

In order to achieve the above object, according to the present invention there is provided a cosmetic composition comprising 1.0 to 10.0% by weight of alpha lipoic acid, 20 to 80% by weight of cyclodextrin, 0.01 to 3.0% by weight of Albino mushroom extract and the remainder of the solvent.

The cyclodextrin is selected from the group consisting of hydroxypropyl beta cyclodextrin, beta cyclodextrin, alpha cyclodextrin, gamma cyclodextrin and glucose, preferably hydroxypropyl beta cyclodextrin.

As the solvent, at least one selected from the group consisting of water, ethanol, methanol, acetone, glycerin, and a fat-soluble solvent may be used.

The cosmetic composition may further include at least one active ingredient selected from the group consisting of vitamin C, vitamin E, glutathione, lipoic acid, coenzyme Q10, folic acid, adenosine, arbutin and ferulic acid.

According to the present invention for achieving the above another object

(A) dissolving and mixing the cyclodextrin as a clathrate in a solvent;

(B) adding a mixture of the aliphatic acid to the mixture of step (A);

(C) mixing the white wood mushroom extract as a stabilizer in addition to the mixture of step (B); And

(D) is provided a method for producing a cosmetic composition comprising the step of correcting the mixture of step (C) to pH 7.0 ~ 9.0.

In addition to the stabilization of alpha lipoic acid in addition to white licorice extract during inclusion stabilization of alpha lipoic acid, the synapse with alpha lipoic acid greatly enhances the whitening activity of cosmetics. .

1 is a graph of the stability test results for the cosmetic composition prepared according to an embodiment of the present invention.
Figure 2 is a graph showing the collagen biosynthesis promoting effect of the cosmetic composition prepared according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

According to an embodiment of the present invention is provided a cosmetic composition comprising 1.0 to 10.0% by weight of alpha lipoic acid, 20 to 80% by weight of cyclodextrin, 0.01 to 3.0% by weight of white fungus extract and the remainder of the solvent.

Alpha Lipoic acid is a compound having a structure as shown in Formula 1 below.

[Formula 1]

The alpha lipoic acid having an antioxidant activity or the like is well dissolved in ethanol or polyol, but oxidized in an aqueous solution to form a dendritic polymer, and there is a problem in that odor is generated in this process, which makes it difficult to use as a component of a cosmetic. Accordingly, the alpha lipoic acid is included in the cyclodextrin to stabilize it. Cyclodextrins are white crystals or crystalline powder, odorless and slightly sweet. Cyclodextrins are ring-shaped oligosaccharides in which 6-12 glucose is α-1,4 glycoside bonded, respectively, and are classified into α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. Soluble in water, slightly soluble in ethanol and decompose at 278 ℃. It has an inclusion function and has both hydrophilic and hydrophobic properties. In addition, it has heat resistance against various acids and alkalis and is also resistant to heating and humidity. The diameter of the cavity of the beta-cyclodextrin is 780 pm (picometer) and the gamma-cyclodextrin is 950 pmm. Crystallographic studies have shown that beta-cyclodextrin cavities are suitable for the reception of spherical shaped guest materials such as adamantane derivatives, with the space enclosed by the head-head dimer being about 2.5 times more than the cavities of single molecules. It is reported that it is wide. It is also known that chemical changes in beta-cyclodextrin alter the size and shape of the cavity. The cyclodextrin may be selected from the group consisting of hydroxypropyl beta cyclodextrin, beta cyclodextrin, alpha cyclodextrin, gamma cyclodextrin and glucose. In the present invention, the cyclodextrin used for inclusion of alpha lipoic acid is preferably hydroxypropyl beta-cyclodextrin (Hydroxypropyl β-Cyclodextrin).

The stability of alpha lipoic acid is greatly improved by adding the cedar mushroom extract. Tremella fuciformis has been used as an edible mushroom. Recently, the chemical structure of several polysaccharides obtained from the fruiting body of the white-necked mushroom has been revealed, and the polysaccharide fragments of the mushroom fruiting body of the white-necked tree are known to exhibit many physiological activities. In the present invention, the cedar mushroom extract used is extracted from the cedar mushroom, specifically, the mushroom polysaccharide extracted from the fruiting body and the extraction method is not limited.

As the solvent, at least one selected from the group consisting of water, ethanol, methanol, acetone, glycerin, and a fat-soluble solvent may be used.

The cosmetic composition may further include at least one active ingredient selected from the group consisting of vitamin C, vitamin E, glutathione, lipoic acid, coenzyme Q10, folic acid, adenosine, arbutin and ferulic acid.

According to the present invention for achieving the above another object (A) dissolving and mixing the cyclodextrin as a clathrate in a solvent; (B) adding a mixture of the aliphatic acid to the mixture of step (A); (C) mixing the white-white mushroom extract as a stabilizer in addition to the mixture of step (B); And (D) there is provided a method for producing a cosmetic composition comprising the step of correcting the mixture of step (C) to pH 7.0 ~ 9.0.

According to one embodiment according to the invention it can be prepared a composition containing alpha lipoic acid stabilized by the following method. After mixing the hydroxypropyl cyclodextrin (Hydroxypropyl Cyclodextrin) in the solvent and the complete water dissolution in hot water at 60 ~ 80 ℃, alpha lipoic acid is further added under 50 ~ 60 ℃ conditions to completely dissolve. When the mixing is completed while maintaining the temperature, the white wood mushroom extract is added and mixed thoroughly. At this time, it is important to minimize the contact with iron, water, oxygen to dissolve. When completely mixed, 1, 2 hexanediol may be added to impart antiseptic activity. Subsequently, KOH, NaOH solution was added to the mixture to prepare a pH of 7.0 to 9.0. Thereafter, the product can be distilled under reduced pressure to the desired weight.

As a result of the stability test of the stabilized alpha lipoic acid, it was confirmed that the stability was greatly improved when the mushroom extract was added. In addition, as a result of testing the stabilized alpha lipoic acid as a cosmetic formulation, it was confirmed that not only the aging stability of the cosmetic was improved, but also the collagen biosynthesis promoting effect and the melanin production inhibitory effect were excellent. It can be seen that the white-brown mushroom extract contributed greatly to the activity of the cosmetics as well as the stability.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples.

Example 1, 2: Preparation of alfalfaic acid stabilizing composition

A stabilizing composition was prepared according to the composition of Table 1 below. Hard hydroxypropyl beta cyclodextrin (Hydroxypropyl β-Cyclodextrin) was added to the solvent and purified water, and then completely dissolved by hot water heating at 60 ~ 80 ℃. After complete dissolution, alpha lipoic acid was added under conditions of 50 to 60 ° C., completely dissolved, and mixed. After the mixing was completed, the mixture was added to the white agar mushroom extract (product name: Tremella Fuciformis Extract, manufactured by SANGHAI HUIWEN BIOTECH CO., LTD.). After complete mixing, 1,2 hexanediol (1,2 Hexanediol) was further added. The pH was then adjusted using a 10% KOH solution in the mixture.

Comparative Examples 1 to 5: preparation of alpha lipoic acid stabilizing composition

It was prepared in the same manner as in Example according to the composition of Table 1.

Category (% by weight) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Purified water TO 100 TO 100 TO 100 TO 100 TO 100 TO 100 TO 100 Hydroxypropyl β-cyclodextrin 60.0 60.0 30.0 40.0 50.0 60.0 60.0 Hexanediol - 2.0 - - - - 2.0 Alpha Lipoic Acid 5.0 5.0 5.0 5.0 5.0 5.0 5.0 White Oyster Mushroom Extract 1.0 1.0 - - - - - pH 8.5 8.5 8.5 8.5 8.5 8.5 8.5

Test Example 1: Stability Test

The alpha-lipoic acid stabilized compositions prepared in Examples and Comparative Examples were subjected to property stability tests and content stability tests.

1. Property stability test

Properties of the alpha lipoic acid stabilized composition prepared in Examples and Comparative Examples were tested under the conditions of Table 2, and the results are shown in Table 2.

Appearance stability test result division 1 day later After 1 week after 2 weeks After 4 weeks 8 weeks later 12 weeks later Example 1


Room temperature ○ ○ ○ ○ ○ ◑ 45 ° C ○ ○ ◑ ◑ ◑ ▣ 4 ℃ ○ ○ ○ ○ ○ ○ Shading room temperature ○ ○ ○ ○ ○ ○ Example 2


Room temperature ○ ○ ○ ○ ○ ◑ 45 ° C ○ ○ ○ ○ ◑ ◑ 4 ℃ ○ ○ ○ ○ ○ ○ Shading room temperature ○ ○ ○ ○ ○ ○ Comparative Example 1


Room temperature ◑ ◑ ▣ ▣ ▣ ★ 45 ° C ◑ ◑ ▣ ▣ ★ ★ 4 ℃ ○ ○ ◑ ◑ ▣ ▣ Shading room temperature ○ ◑ ▣ ▣ ▣ ★ Comparative Example 2


Room temperature ○ ◑ ◑ ◑ ▣ ▣ 45 ° C ◑ ◑ ◑ ◑ ▣ ★ 4 ℃ ○ ○ ○ ○ ◑ ▣ Shading room temperature ○ ○ ◑ ◑ ◑ ▣ Comparative Example 3


Room temperature ○ ○ ○ ◑ ◑ ◑ 45 ° C ○ ○ ◑ ◑ ▣ ▣ 4 ℃ ○ ○ ○ ○ ○ ○ Shading room temperature ○ ○ ○ ○ ○ ◑ Comparative Example 4


Room temperature ○ ○ ○ ○ ◑ ◑ 45 ° C ○ ○ ○ ○ ◑ ◑ 4 ℃ ○ ○ ○ ○ ○ ○ Shading room temperature ○ ○ ○ ○ ○ ◑ Comparative Example 5


Room temperature ○ ○ ○ ○ ◑ ◑ 45 ° C ○ ○ ○ ◑ ◑ ◑ 4 ℃ ○ ○ ○ ○ ○ ○ Shading room temperature ○ ○ ○ ○ ◑ ◑

(○: no change, ◑: weak color change, ▣: many color change and suspension, ★: complete color change and precipitation)

As confirmed in Table 2, the compositions of Examples 1 and 2, which contain white mushroom extract, were superior in phase stability as compared to the comparative examples.

2.Content stability test

The content of the alpha lipoic acid stabilizing composition prepared in Examples and Comparative Examples was tested for the content stability under the conditions of Table 3, and the results are shown in Table 3.

division Example 2 Comparative Example 4 Comparative Example 5 Room temperature 45 ° C 4 ℃ Shading room temperature Room temperature 45 ° C 4 ℃ Shading room temperature Room temperature 45 ° C 4 ℃ Shading room temperature Early 100 100 100 100 100 100 100 100 100 100 100 100 2 weeks 100 100 100 100 91 88 98 95 95 90 98 98 4 weeks 100 100 100 100 86 81 90 88 91 86 95 93 8 weeks 100 99 100 100 80 77 86 83 86 81 90 88 12 Weeks 99 97 100 99 76 72 81 79 80 78 84 82

As confirmed in Table 3, the composition of Example 2 containing an extract of Albino mushroom was superior in content stability compared to the comparative examples.

Example 3: Preparation of Cosmetic Composition Containing Stabilized Alpha Lipoic Acid

Cream containing the stabilized alpha lipoic acid prepared in the above Example was prepared according to the conventional method according to the composition of Table 4.

ingredient Weight (g) Wax 2.0 Stearic Acid Monoglycerin 3.0 Liquid paraffin 4.0 Polysorbate 5.0 Squalene 5.0 Hyaluronic acid 0.3 Lysine 0.3 glycerin 4.0 1,3 butylene glycol 8.0 Stabilized Alpha Lipoic Acid (Example 2) 10.0 Spices 0.001 antiseptic 0.3 Purified water 58.1 total 100.0

Test Example 2: Formulation Stability Test

The stability test for the cosmetic composition prepared in Example 3 was carried out. It was tested according to the content analysis method. HPLC conditions are as follows.

Content Analysis (HPLC Test Methods)

-Standard: Alpha-Lipoic acid (99.29%)

-Detector: UV-VIS Detector (330 nm)

Column: Mightysil RP-18 GP 250-4.6 (5 um)

Mobile phase: (MeOH: Water) + 0.1% Acetic acid / 70: 30

Flow rate: 1 mL / min

The results are shown in FIG. As confirmed in FIG. 1, there was no change in its content with time, and it was confirmed that time stability was excellent.

Test Example 3: Collagen Biosynthesis Promotion Effect Test

Fibroblasts were inoculated in IMDM medium with 10% FBS at a cell concentration of 5 × 10 ⁵ and incubated in 37 ° C., 5% CO ₂ incubator for 24 hours. A dilution solution prepared by diluting the stabilized alpha-lipoic acid-containing cosmetic composition containing the white myrtle mushroom extract of Example 3 in dimethyl sulfoxide so as to have a final concentration of 50, 100, 500, and 1000 µg / ml was incubated for 24 hours. After 18 hours incubation under the same conditions was irradiated with UV for 1 hour to give a stress to the cells. Thereafter, the fibroblasts were recovered using Trizol reagent (invitrogen, USA), mRNA was extracted, and cDNA was synthesized through a series of processes. The amount of gene expression was confirmed by electrophoresis by amplifying the PROCOLLAGEN TYPE I gene region from the synthesized cDNA, and gene amplification was performed using thermal cycler (GenePro, Hangzhou bioer tech., CHINA) using 10x taq polymerase buffer, 10 mM dNTP, 10 pmol primer (F: AGC CAG CAG ATC GAG AAC AT, R: TCT TGT CCT TGG GGT TCT TG), mixed with taq polymerase and adjusted to 50 uL with distilled water 95 ° 5 min 1 cycle / 95 ° 1 min / 51 ° 2 cycles / 72 degrees 1 minutes 28 cycles amplification, was carried out under the conditions of reacting for 5 minutes at 72 degrees. The expression rate of the produced procollagen was calculated according to the following equation. As a control, normal fibroblasts without treatment of the sample and UV irradiation were used. As a comparative example, the cosmetic composition containing the stabilizing alpha lipoic acid of Comparative Example 5, which did not contain the mushroom extract, was prepared and used in the same manner as in Example 3.

Procollagen Expression (%) = B / A × 100 (%)

A: amount of procollagen expression in the control group

B: Procollagen Expression Levels of Sample Treatment and UV Irradiated Fibroblasts

The test results are shown in Table 5 and FIG. 2.

Sample concentration
(Μg / ml) procollagen expression rate (%) Example 3 Cosmetic Composition Comparative Example 5 Cosmetic Composition con 100.00 100.0 10 100.14 100.0 50 111.77 106.98 100 216.62 174.26

As can be seen from the results of Table 5, as the content of the sample to which the alpha lipoic acid-containing cosmetic composition stabilized by the fungus extract was increased, the effect of promoting collagen biosynthesis related to skin wrinkles was higher. The results are shown in FIG. In addition, as confirmed in Table 5, the white neck showed a much better effect than the cosmetic composition of Comparative Example 5 containing no mushroom extract.

Experimental Example 4: Whitening Activity Test of Cosmetic Composition

1. Melanin production inhibitory effect test

B16F10 cells were inoculated in 2 ml of DMEM medium added with 10% FBS per well to a 6-well plate at a concentration of 2 × 10 ⁵ and incubated in a 37 ° C., 5% CO ₂ incubator for 24 hours. After culturing for 24 hours, the wells were exchanged with fresh medium, and the diluting solution prepared by diluting the cosmetic composition of Example 3 to 62.5, 125, and 250 µg / ml, respectively, was added to the same conditions for 18 hours. Incubated at. The cells were then washed with PBS, treated with 300 μl of 0.25% trypsin-EDTA, collected and transferred to a microcentrifuge tube, and then centrifuged at 1,000 rpm for 4 minutes. The precipitated cells were washed twice with PBS, and 500 µl of 1N NaOH was added to dissolve melanin. To help dissolve melanin, the reaction was carried out at 100 ° C. for 10 minutes. The amount of melanin in each microcentrifuge tube was determined spectrophotometrically by measuring absorbance at 400 nm.

The test results were obtained as shown in Table 6 below.

Sample concentration (㎍ / ㎖) Melanin synthesis inhibition (%) Example 3 Cosmetic Composition Comparative Example 5 Cosmetic Composition 0  0.00 0.00 10 30.90 23.11 50 37.49 29.65 100 45.53 37.44

The higher the melanin synthesis inhibition (Melanin synthesis inhibition) is the production of melanin is suppressed, as shown in Table 6 when the composition of Example 3 treated melanin biosynthesis inhibition rate shows an excellent melanin production inhibitory effect It was found that, as the concentration increases there was a synergistic effect. In addition, as shown in Table 6, the white neck showed a much better effect than the cosmetic composition of Comparative Example 5 containing no mushroom extract.

2.TRP-1, TRP-2 and Mu-tyr expression inhibitory effect test

B16F10 cells were inoculated in DMEM medium with 10% FBS at a concentration of 5 × 10 ⁵ and incubated in 37 ° C., 5% CO ₂ incubator for 24 hours. Incubated for 24 hours, the diluted alpha lipoic acid cosmetic composition prepared in Example 3 was diluted to dimethyl sulfoxide to 50 and 100 µg / ml, respectively, and incubated under the same conditions for 18 hours. Thereafter, B16F10 cells were recovered using Trizol reagent (invitrogen, USA), mRNA was extracted, and cDNA was synthesized through a series of processes. From the synthesized cDNA, TRP-1 (Tyrosinase related protein-1), TRP-2 (Tyrosinase related protein-2) and Mu-tyrosinase gene regions were amplified to confirm the expression level of the gene by electrophoresis. (GenePro, Hangzhou bioer tech., CHINA) using 10x taq polymerase buffer, 10 mM dNTP, 10 pmol primer (TRP-1 F: AGG AAT CTG GCT TGG GAT TT, TRP-1 R: ATG AGC CAC AAG GGT CAG TC, TRP-2 F: AGC AGA CGG AAC ACT GGA CT, TRP-2 R: CAG GTA GGA GCA TGC TAG GC, Mu-tyr F: GGG CCC AAA TTG TAC AGA GA, Mu-tyr R: GGC AAA TCC TTC CAG TGT GT), taq polymerase was mixed and distilled water was adjusted to 50 uL, then 94 ° 5 min 1 cycle / 94 ° 30 sec / 52 ° 30 sec (TRP-1), 53 ° 30 sec (TRP-2, Mu- tyr) / 72 degrees 30 seconds 35 cycles amplification, was carried out under the conditions for 5 minutes reaction at 72 degrees. The expression inhibition rate of the generated TRP-1, TRP-2 and Mu-tyr was calculated according to the following equation, and the control group used normal B16F10 cells without treatment.

Expression inhibition rate (%) = {1- (B / A)} × 100 (%)

A: the amount of TRP-1, TRP-2 and Mu-tyr expression in the control group

B: Sample Processing and TRP-1, TRP-2 and Mu-tyr Expression in B16F10 Cells

The test results were obtained as shown in Table 7 below.

sample
density
(Μg / ml) Expression inhibition rate (%) TRP-1 TRP-2 Mu-tyr Example 3
Cosmetics Comparative Example 5
Cosmetics Example 3
Cosmetics Comparative Example 5
Cosmetics Example 3
Cosmetics Comparative Example 5
Cosmetics 0 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 100 19.70 13.05 41.68 28.64 16.81 11.21

As confirmed in the results of Table 7, TRP-1, TRP-2, and Mu-tyr, which are genes involved in melanin synthesis, were not applied when the alpha lipoic acid cosmetic composition with enhanced stability of Example 3 was not applied. The expression of was suppressed and showed a better effect as the concentration was increased. In addition, as confirmed in Table 7, the white neck showed a much better effect than the cosmetic composition of Comparative Example 5 containing no mushroom extract.

Test Example 5: Cytotoxicity Test

Fibroblasts were inoculated in IMDM medium with 10% FBS at a cell concentration of 5 × 10 ⁵ and incubated for 24 hours in a 37 ° C., 5% CO 2 incubator. After incubation, the medium was removed, and the diluted lipoic acid cosmetic composition having enhanced stability of Example 3 was treated with a diluting solution prepared by diluting the dimethyl sulfoxide to a final concentration of 50, 100, 500, and 1000 µg / ml for 24 hours. After incubation, 100 μl of MTT (3- [4,5-dimethylthiazol-2yl] -2,5-diphenyltetrazolium boromide, Sigma, USA) solution was added to each well (3 mg / ml) and further incubated for 4 hours. It was. Then, the supernatant was removed, 150 μl of dimethyl sulfoxide was added, and the generated formazan was dissolved by shaking for 30 minutes, and the absorbance was measured at 540 nm using a multimicroplate reader (Molecular device Spectra max190). Cell viability was calculated according to the following formula and the results are shown in Table 8 below.

Cell viability (%) = absorbance of the sample addition group / absorbance of the control group × 100

Sample concentration (µg / mL) Cell survival rate (%) Con 100 6.25 100 12.5 95.97 25 91.94 50 88.17 100 80.97

As shown in the results of Table 8, all of the samples to which the alpha-lipoic acid cosmetic composition with enhanced stability of Example 3 was applied were found to have no cytotoxicity at the concentration of 6.25 µg / ml, and the cell viability at the concentration of 100 µg / ml. Although this decreases, it is confirmed that there is no problem in safety.

Claims (4)

(A) adding a hydroxypropyl beta cyclodextrin (Hydroxypropyl β-Cyclodextrin) as a clathrate in water as a solvent, followed by dissolving by mixing in warm water at 60 ~ 80 ℃;
(B) adding alpha lipoic acid to the mixture of step (A) under 50 to 60 ° C. and mixing the mixture;
(C) mixing the cedar mushroom extract in addition to the mixture of step (B); And
(D) comprising the step of calibrating the mixture of step (C) to pH 7.0 ~ 9.0,
The hardoxypropyl beta cyclodextrin (Hydroxypropyl β-Cyclodextrin) is 20 to 80% by weight, the alpha lipoic acid is 1.0 to 10.0% by weight, the white fungi extract is 0.01 to 3.0% by weight, water is added as a balance How to stabilize the alpha lipoic acid.
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