KR100430606B1 - Cosmetic Compositions Comprising Lactic Acid and Arbutin for Skin Whitening - Google Patents

Abstract

The present invention relates to a whitening cosmetic composition comprising lactic acid and arbutin as active ingredients, and more particularly to a whitening cosmetic composition comprising 7 to 9% by weight lactic acid and 0.5 to 1.5% by weight arbutin as active ingredients. The cosmetic composition of the invention exhibits an improved whitening effect with very low skin irritation.

Description

Cosmetic Compositions Comprising Lactic Acid and Arbutin for Skin Whitening

The present invention relates to a cosmetic composition, and more particularly to a whitening cosmetic composition comprising lactic acid and arbutin as an active ingredient.

Human skin color is generally determined by the quinone complex called melanin, which is synthesized by melanin forming cells present in the basal cell layer of the epidermis. The monomer that forms melanin is an amino acid tyrosine, which is converted to dopa by a tyrosinase enzyme, oxidized and converted back to dopa quinone. The synthesized melanin is collected in a cell organelle called melanosomes and transferred to keratinocytes through dendritic processes. Numerous factors influence melanin production, and the ultraviolet rays irradiated to the skin play the most important role in melanin formation. Melanin plays a beneficial role in eliminating free radicals and free radicals naturally occurring in the human skin or preventing the transmission of ultraviolet rays that cause much harm to the skin. However, since tyrosinase is more activated by ultraviolet light, it is well known that the skin turns black when exposed to a lot of ultraviolet light.

One of the areas of greatest interest in East Asian women, especially in Korea, Japan, and China, is the skin whitening. As used herein, the term "skin whitening" may be referred to as a concept of arranging changes in skin color caused by excessive generation of pigments in the skin due to external environmental changes such as ultraviolet rays, stress, hormone secretion abnormalities, and pregnancy.

Mechanisms on whitening are well known in many patent documents (e.g., Korean Patent Publication No. 2000-74101) and papers. Inhibition and inflammation-inducing cells of tyrosinase, an enzyme that induces melanin synthesis activated by UV light The method resulting from the inhibition of signaling substances produced by and promoting melanin production has been elucidated in detail.

Representative whitening materials known to date include arbutin contained in alpine plants, such as bilberry leaves, and the cultures of spawns that make miso, liquor, etc., found from the whitening of people handling rice bran. Kojic acid extracted from the skin, whitening raw material stabilized in vitamin C, and placenta extract extracted from cow and sheep placenta, which contain various enzymes, vitamins and amino acids. Placenta, rucinol, which exerts the same block effect as capsules when inhibiting tyrosinase activity, gao extracted from chamomile, endothelin, an ingredient originally developed Camomile extracts, a whitening ingredient that inhibits melanogenesis at an early stage.

In addition, four types of functional cosmetics that are useful for skin whitening are reported in the functional cosmetic standard and test method according to the provisions of Article 4, Paragraph 1 of Cosmetic Act No. 2001-44 of the Korea Food and Drug Administration. Firstly, it is a powder obtained by extracting the middle or root of the mulberry (Broussonetia kazinoki) and the same plant (Moraceae) with ethanol and ethyl acetate or a 2 w / v% butylene glycol solution of the powder. The tyrosinase inhibition rate of the said raw material is shown to be 48.5 to 88.1%. Secondly, arbutin and ethyl ascorbyl ether are mentioned above, and derivatives of vitamin C and finally useful licorice extract are disclosed.

Korean Patent Laid-Open Publication No. 1998-73162 discloses a whitening cosmetic product comprising an active ingredient of a powder obtained by adsorbing a whitening substance such as arbutin on titanium dioxide silica, and Korean Patent Laid-Open Publication No. 2000-50464 includes a whitening agent such as arbutin. A functional cosmetic composition of a powder form is disclosed. In addition, Korean Patent Publication No. 2001-25288 discloses a cosmetic composition having a whitening function comprising a protocatecuic aldehyde, an inhibitor of tyrosinase, as an active ingredient.

Throughout this specification, a patent document is referred and the citation is shown. The disclosures of the cited patent documents are incorporated by reference herein in their entirety, and the level of the technical field to which the present invention belongs and the contents of the present invention are more clearly described.

The present inventors have completed the present invention by confirming that the whitening effect is synergistically demonstrated when lactic acid and arbutin are used as an active ingredient and the ingredient ratio is properly adjusted as a result of the intensive research efforts to develop a cosmetic composition showing a more improved whitening effect. .

Accordingly, it is an object of the present invention to provide a cosmetic composition with improved whitening effect.

1 is a graph showing the value measured by the Minolta CR 300 of the color change of the skin to which the whitening cosmetic composition of the present invention is applied.

The present invention provides a whitening cosmetic composition comprising 7 to 9% by weight of lactic acid and 0.5 to 1.5% by weight of arbutin as active ingredients.

Arbutin used as an active ingredient in the present invention is a component that inhibits the activity of tyrosinase and shows a whitening effect, and has already been used in various kinds of cosmetics. The present inventors have studied in various ways to improve the whitening effect of arbutin, and when combined with arbutin, lactic acid, which inhibits the production of tyrosinase, has shown a synergic whitening effect. The synergistic effect is presumably due to the different mechanism of arbutin and lactic acid, that is, arbutin exhibits a whitening effect through inhibition of tyrosinase activity and lactic acid inhibits tyrosinase formation. The synergistic effect of the whitening effect by the combination of lactic acid and arbutin was first identified and attempted by the inventors.

The lactate and arbutin used as active ingredients in the present invention are preferably present in an amount of 7 to 9% by weight of lactic acid and 0.5 to 1.5% by weight of arbutin with respect to the total cosmetic composition, each of which is used independently or in a different weight ratio. It shows an excellent whitening effect than when used by mixing. When the content of lactic acid in the cosmetic composition of the present invention is less than 7% by weight, the whitening effect is reduced than when 8% by weight is used, and when it exceeds 9% by weight, there is no obvious effect due to the increase in content. In addition, when the content of arbutin in the cosmetic composition of the present invention is less than 0.5% by weight can not be expected synergistic effect of whitening effect by different mechanisms, when exceeding 1.5% by weight it is expected to have a distinct effect by increasing the content Can't. Most preferred contents are 8.0% by weight lactic acid and 1.0% by weight arbutin.

On the other hand, lactic acid used as an active ingredient in the cosmetic composition of the present invention exhibits an effect of increasing the level of moisturizing effect and natural ceramide in the skin in addition to the whitening effect in the cosmetic composition. However, lactic acid, a type of AHA (α-hydroxyacid), has a decisive side effect of causing skin inflammation and is therefore considered the biggest problem of cosmetics containing AHA.

In the cosmetic composition of the present invention, the pH of the final cosmetic composition is adjusted to minimize skin irritation by lactic acid. Lactic acid exists in the form of lactic acid in the environment below pH 5.0, which has a harmful effect on the skin, but in the environment above pH 5.0, it exists in the form of salt (lactate) and can be effectively absorbed into the skin without adversely affecting the skin. The inventors confirmed this. Therefore, when maintaining a suitable pH range, irritation to the skin is greatly reduced even if the lactic acid is contained in a large amount in the cosmetic. Finally, according to a preferred embodiment of the present invention, the pH of the cosmetic composition of the present invention is 4.5 to 6.0. If the pH is less than 4.5, there is a problem that the skin irritation caused by lactic acid is greatly increased, and if the pH is higher than 6.0, AHA cannot have activity and the alkali component irritates the skin.

According to the most preferred embodiment of the present invention, the present invention provides a whitening cosmetic composition comprising 8.0% by weight of lactic acid and 1.0% by weight of arbutin as an active ingredient and having a total pH of 5.0. In the case of preparing the cosmetic composition as such a composition, not only the synergistic increase in the whitening effect can be obtained but also a minimized irritation to the skin.

The components included in the cosmetic composition of the present invention include components commonly used in cosmetic compositions in addition to lactic acid and arbutin as active ingredients, and include, for example, conventional auxiliaries such as antioxidants, stabilizers, solubilizers, vitamins, pigments and flavorings, And carriers.

The skin care composition of the present invention may be prepared in any formulation conventionally prepared in the art, for example, solutions, suspensions, emulsions, pastes, gels, creams, lotions, powders, soaps, surfactant-containing It may be formulated as cleansing, oil, powder foundation, emulsion foundation, wax foundation, spray, and the like, but is not limited thereto. More specifically, it may be prepared in the form of a flexible lotion, nutrition lotion, nutrition cream, massage cream, essence, eye cream, cleansing cream, cleansing foam, cleansing water, pack, spray or powder.

When the formulation of the present invention is a paste, cream or gel, animal oils, vegetable oils, waxes, paraffins, starches, trachants, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicas, talc or zinc oxide may be used as carrier components. Can be.

When the formulation of the present invention is a powder or a spray, lactose, talc, silica, aluminum hydroxide, calcium silicate or polyamide powder may be used, in particular in the case of a spray, additionally chlorofluorohydrocarbon, propane Propellant such as butane or dimethyl ether.

When the formulation of the present invention is a solution or emulsion, a solvent, solubilizer or emulsifier is used as the carrier component, such as water, ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1 Fatty acid esters of, 3-butylglycol oil, glycerol aliphatic ester, polyethylene glycol or sorbitan.

When the formulation of the present invention is a suspension, liquid carrier diluents such as water, ethanol or propylene glycol, suspending agents such as ethoxylated isostearyl alcohol, polyoxyethylene sorbitol ester and polyoxyethylene sorbitan ester, microcrystals Soluble cellulose, aluminum metahydroxy, bentonite, agar or tracant and the like can be used.

When the formulation of the present invention is a surfactant-containing cleansing, the carrier component is an aliphatic alcohol sulfate, an aliphatic alcohol ether sulfate, a sulfosuccinic acid monoester, isethionate, an imidazolinium derivative, a methyltaurate, a sarcosinate, a fatty acid amide. Ether sulfates, alkylamidobetaines, aliphatic alcohols, fatty acid glycerides, fatty acid diethanolamides, vegetable oils, lanolin derivatives or ethoxylated glycerol fatty acid esters and the like can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention in more detail, it is to those skilled in the art that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention. Will be self-evident.

Preparation Example 1 Preparation of Cosmetic Composition

In order to determine the proper ratio of lactic acid and arbutin and the suitable pH in the whitening cosmetic composition, the cosmetics A, B, C, D, E and F were prepared while adjusting the mixing ratio and pH of lactic acid and arbutin in the composition of Table 1 below. It was.

ingredient A prescription B prescription C prescription D prescription E prescription F prescription glycerin 4.0 * 4.0 4.0 4.0 4.0 4.0 Sodium lactate 60% 2.0 2.0 2.0 2.0 2.0 2.0 Propylparaben 0.2 0.2 0.2 0.2 0.2 0.2 EDTA-2Na 0.02 0.02 0.02 0.02 0.02 0.02 Polysorbate 60 1.0 1.0 1.0 1.0 1.0 1.0 Glycerin stearate 1.5 1.5 1.5 1.5 1.5 1.5 Vis wats 2.0 2.0 2.0 2.0 2.0 2.0 Jojoba oil 8.0 8.0 8.0 8.0 8.0 8.0 KOH 0.45 0.45 0.15 0.45 0.45 0.15 BHT 0.05 0.05 0.05 0.05 0.05 0.05 pf. Kn-753 0.3 0.3 0.3 0.03 0.3 0.3 Lactic acid 8.0 8.0 - 8.0 5.0 - Arbutin 1.0 - 1.0 1.0 2.0 - Purified water Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount Remaining amount pH 5.0 5.0 5.0 4.0 5.0 5.0 system 100 100 100 100 100 100 * Unit is weight percent.

Example 1: Skin irritation test

In order to determine the skin irritation of each cosmetic prepared in the above preparation, 0.1 g of each sample was patched for 24 hours at 5 × 20 cm in the lower part of both arms for 50 healthy adults male and female. After the passage, the skin condition change was read visually, and the stimulation rate was calculated by the following equation. The results are shown in Table 2.

Formulation Number of test subjects Judgment result Stimulation rate ++ + +- - A 50 - - 4 46 2.6 B 50 - - 3 47 2.0 C 50 - - 2 48 1.3 D 50 - 3 6 41 8.0 E 50 - One 3 46 3.3 F 50 - - 2 48 1.3

Criteria

-: No erythema or unusual phenomenon

+-: Slightly reddish

+: Significantly redder than the surroundings

++: Severe reddening and swelling around

As can be seen in Table 2, prescriptions A, B, C and F showed a low skin irritation rate.

Example 2: Whitening Effect Measurement

Thirty women aged 19 to 40 with dark skin were measured for the whitening effect of each formulation prepared in Preparation Example. Seven arms of the test subjects were marked by 1 cm in width and length, and each cosmetic was applied, and the other one was used as a control. Subsequently, the whitening degree (L value) was measured at 2 week intervals for 2 months using Minolta CR 300 (Minolta, Japan). The results are shown in FIG.

As can be seen in Figure 1, Cosmetic A was found to exhibit a whitening effect of more than 13 to 80% compared to other cosmetics and the control.

In summary, the results of Examples 1 and 2, Formula A, i.e., 8.0% by weight of lactic acid and 1.0% by weight of arbutin, the cosmetic composition having a total pH of 5.0 of the cosmetic composition is the best skin whitening effect with the smallest skin irritation rate It can be seen that the most preferred whitening cosmetic composition showing. In addition, Prescription B does not contain arbutin and has a small whitening effect, Prescription C does not contain lactic acid and has a small whitening effect, and Prescription D has a low pH and has a high skin irritation rate and a small whitening effect. Formula E contains different ratios of lactic acid and arbutin than Formula A and has a small whitening effect.

In conclusion, in the whitening cosmetic composition comprising lactic acid and arbutin, it can be seen that the content and pH of the ingredient are very important factors in terms of skin irritation rate and whitening effect, and it contains 8.0 wt% lactic acid and 1.0 wt% arbutin and the cosmetic composition It can be seen that the cosmetic composition having a total pH of 5.0 is the most preferred whitening cosmetic composition exhibiting the best whitening effect while having a small skin irritation rate.

As described in detail above, the present invention provides a whitening cosmetic composition. The cosmetic composition of the present invention exhibits an improved whitening effect with very low skin irritation.

Claims (4)

A whitening cosmetic composition comprising 7 to 9% by weight of lactic acid and 0.5 to 1.5% by weight of arbutin as active ingredients. The whitening cosmetic composition according to claim 1, wherein the cosmetic composition has a pH of 4.5 to 6.0. The method of claim 1 wherein the whitening cosmetic composition is a solution, suspension, emulsion, paste, gel, cream, lotion, powder, soap, surfactant-containing cleansing, oil, powder foundation, emulsion foundation, wax foundation and spray A whitening cosmetic composition comprising a formulation selected from the group consisting of. A whitening cosmetic composition comprising 8.0 wt% lactic acid and 1.0 wt% arbutin as active ingredients, and having a total pH of 5.0.