KR20210022240A - Whitening cosmetic compositions of oil in water emulsion with vitamin C derivative stable - Google Patents

Abstract

The present invention relates to an oil-in-water type cosmetic composition for skin whitening, containing a stable vitamin C derivative.

Description

Whitening cosmetic compositions of oil in water emulsion with vitamin C derivative stable}

The present invention relates to an oil-in-water type whitening cosmetic composition stably containing a vitamin C derivative.

The development of high-vitamin products is on the rise as the need for high-efficiency products and the actual effects of whitening and wrinkle improvement functional cosmetics are increasing.

Vitamin C is a mechanism that inhibits the activity of tyrosinase in the skin, inhibits melanin formation, and promotes collagen synthesis, helping to whiten the skin and prevent aging.

However, due to the nature of the raw material, it is easily oxidized and destabilized by light and heat. The solubility in water (330 g/L) is large and it dissolves easily. However, since the rate at which the oxidation stability decreases in an aqueous solution is high, it is not easy to stabilize the emulsion when a high content of vitamin C is blended.

In order to improve this problem, various vitamin C derivatives with improved oxidation stability of vitamin C have been developed. However, the development of a cosmetic that improves destabilization such as a decrease in potency due to oxidation according to a change over time and instability such as discoloration or a decrease in the viscosity of a formulation when blended in a high content in an oil-in-water type emulsion is insignificant.

Korean Patent Registration No. 10-1817765 Korean Patent Registration No. 10-0252552 Korean Patent Publication No. 10-2007-0089327

It is an object of the present invention to provide an oil-in-water type whitening cosmetic composition stably containing a vitamin C derivative.

The present invention relates to an oil-in-water type whitening cosmetic composition stably containing a vitamin C derivative.

Hereinafter, the present invention will be described in more detail.

An example of the present invention relates to an oil-in-water type whitening cosmetic composition stably containing a vitamin C derivative.

The composition of the present invention contains a vitamin C derivative, 0.1 to 5.0% by weight of a pH adjuster, 0.1 to 5.0% by weight of a thickener, 1.0 to 20.0% by weight of an oil component, 0.1 to 5.0% by weight of a surfactant, and purified water based on the total weight of the composition. I can.

In the present invention, the oxidation stability of the whitening cosmetic composition containing the vitamin C derivative is improved in a pH condition (pH 4-6) in a range similar to that of the raw material, so that the viscosity decrease and discoloration of the oil-in-water emulsion do not occur. It was confirmed that the titer of the C derivative was maintained. Through clinical evaluation of the prepared oil-in-water emulsion, it was confirmed that the skin brightness and transparency of the subject were improved.

In the present invention, the vitamin C derivative is 1.0 to 30.0 wt%, 2.0 to 30.0 wt%, 3.0 to 30.0 wt%, 4.0 to 30.0 wt%, 1.0 to 25.0 wt%, 2.0 to 25.0 wt%, 3.0 to 25.0 wt%, 4.0 to 25.0 wt%, 1.0 to 20.0 wt%, 2.0 to 20.0 wt%, 3.0 to 20.0 wt%, 4.0 to 20.0 wt%, 1.0 to 15.0 wt%, 2.0 to 15.0 wt%, 3.0 to 15.0 wt% %, 4.0 to 15.0 wt%, 1.0 to 10.0 wt%, 2.0 to 10.0 wt%, 3.0 to 10.0 wt%, 4.0 to 10.0 wt%, for example 5.0 wt%. If the content of the vitamin C derivative is less than 1.0% by weight, it is difficult to expect a whitening effect, and if it is more than 30.0% by weight, there is a concern of skin irritation.

In the present invention, the vitamin C derivative is ethyl ascorbyl ether, ascorbyl palmitate, ascorbyl tetra-isopalmitate, ascorbyl glucoside, for example For example, it may be ethyl ascorbyl ether, but is not limited thereto.

In the present invention, the pH adjusting agent is 0.1 to 5.0% by weight, 0.1 to 4.0% by weight, 0.1 to 3.0% by weight, 0.1 to 2.0% by weight, 0.1 to 1.0% by weight, 0.1 to 0.9% by weight, 0.1 to 0.8% by weight, 0.1 to 0.7% by weight, 0.1 to 0.6% by weight, 0.1 to 0.5% by weight, 0.1 to 0.4% by weight, 0.1 to 0.3% by weight, 0.1 to 0.2% by weight, for example, 0.1% by weight I can. If the content of the pH adjuster is less than 0.1% by weight, it is difficult to expect a cream formulation with a high viscosity because the thickener cannot be neutralized. If it is more than 5.0% by weight, the pH increases and the stability of the vitamin C derivative decreases.

In the present invention, the pH adjusting agent may be one or more selected from the group consisting of triethanolamine, tromethamine, sodium hydroxide, potassium hydroxide, aminomethylpropanol, and arginine, but is not limited thereto.

In the present invention, the thickener may be a carbomer, but is not limited thereto.

In the present invention, the thickener is 0.1 to 5.0% by weight, 0.1 to 4.0% by weight, 0.1 to 3.0% by weight, 0.1 to 2.0% by weight, 0.1 to 1.0% by weight, 0.2 to 5.0% by weight, 0.2 to 4.0 wt%, 0.2 to 3.0 wt%, 0.2 to 2.0 wt%, 0.2 to 1.0 wt%, 0.3 to 5.0 wt%, 0.3 to 4.0 wt%, 0.3 to 3.0 wt%, 0.3 to 2.0 wt%, 0.3 to 1.0 wt% %, 0.4 to 5.0% by weight, 0.4 to 4.0% by weight, 0.4 to 3.0% by weight, 0.4 to 2.0% by weight, 0.4 to 1.0% by weight, for example, may be 0.5% by weight. If the thickener is less than 0.1% by weight, it is difficult to expect an increasing effect, and if it is more than 5.0% by weight, the characteristic sticky feeling is not good.

In the present invention, the oil component can be applied to all oil components commonly used in cosmetics, for example, Caprylic/Capric Triglyceride, cetylethylhexa to help the skin moisturizing effect. Noate (Cetyl Ethylhexanoate), Cetylhexyl Palmitate (Ethylhexyl Palmitate), Neopentyl Glycol Dicaprate, Triethylhexanoin, Hydrogenated Polydecene, Dime It may be one or more selected from the group consisting of dimethicone, cyclopentasiloxane, and cyclohexasiloxane, but is not limited thereto.

In the present invention, the oil component is 1.0 to 20.0% by weight, 1.0 to 15.0% by weight, 1.0 to 10.0% by weight, 1.0 to 5.0% by weight, 2.0 to 20.0% by weight, 2.0 to 15.0% by weight, 2.0 to 10.0% by weight, 2.0 to 5.0% by weight, for example, may be included in 3.0% by weight. When applied on the skin, the oil component forms a thin film of oil, which helps moisturize because it prevents evaporation of moisture from the skin. Therefore, when the oil component is included in less than 1.0% by weight, it is difficult to expect a moisturizing effect, which is the basic effect of cosmetics, and when it exceeds 20.0% by weight, the feeling of use deteriorates due to the oiliness of the raw material.

In the present invention, the surfactant can be applied to any of the nonionic surfactants used in the preparation of an oil-in-water emulsion. For example, polysorbate 60, polyglyceryl-3 methylglucose distearate (Polyglyceryl- 3 Methylglucose Distearate), Cetearyl Glucoside, C12-20 Alkyl Glucoside, Cetearyl Olivate, Sorbitan Olivate and PEG-100 Stea Rate (PEG-100 Stearate) may be one or more selected from the group consisting of, but is not limited thereto.

In the present invention, the surfactant is 0.1 to 5.0% by weight, 0.1 to 4.0% by weight, 0.1 to 3.0% by weight, 0.1 to 2.0% by weight, 0.5 to 5.0% by weight, 0.5 to 4.0% by weight, 0.5 to 3.0% by weight, 0.5 to 2.0% by weight, 1.0 to 5.0% by weight, 1.0 to 4.0% by weight, 1.0 to 3.0% by weight, 1.0 to 2.0% by weight, for example, 1.5% by weight may be included. Surfactants help in long-term stability by hardening the oily interface in an oil-in-water emulsion. If the content of the surfactant is less than 0.1% by weight, long-term stability may be deteriorated, and if a surfactant having a small molecular weight is used, the content of 5.0% by weight or more may cause skin irritation.

The present invention relates to an oil-in-water type whitening cosmetic composition stably containing a vitamin C derivative, and since there is no drop in titer due to oxidation of the main component, a stable oil-in-water type whitening cosmetic containing a large amount of vitamin C derivative can be prepared, Without the addition of an anti-discoloration agent, discoloration does not occur under high temperature (45° C.) and room temperature conditions, and a weakly acidic (pH 4 to 5) oil-in-water emulsion similar to a vitamin C derivative and skin pH can be prepared.

1A is a photograph showing a result of confirming the stability (whether discoloration) of Example 1 prepared according to an embodiment of the present invention.
1B is a photograph showing a result of confirming the stability (whether discoloration) of Comparative Example 1 prepared according to an embodiment of the present invention.
1C is a photograph showing a result of confirming the stability (whether discoloration) of Comparative Example 2 prepared according to an embodiment of the present invention.
1D is a photograph showing a result of confirming the stability (whether discoloration) of Comparative Example 3 prepared according to an embodiment of the present invention.
1E is a photograph showing a result of confirming the stability (whether discoloration) of Comparative Example 4 prepared according to an embodiment of the present invention.
2 is a graph showing a result of evaluating the effect of improving skin brightness according to an embodiment of the present invention.
3 is a photograph showing a result of evaluating the effect of improving skin brightness according to an embodiment of the present invention.
4A is a graph showing results of evaluating the effect of improving skin transparency according to an embodiment of the present invention.
4B is a graph showing results of evaluating the effect of improving skin transparency according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail by the following examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited by these examples.

Manufacturing example. Example 1 and Comparative Examples 1 to 4

In Example 1 and Comparative Examples 1 to 4, each raw material was weighed in a beaker according to the components and contents shown in Table 1 below, and then uniformly at 7000 rpm for 3 minutes using a Homo mixer at a temperature of 75 to 80°C. Mixed well. After mixing, the thickener was added at the same temperature and uniformly mixed for 3 minutes at 7000 rpm. After mixing, the oily component was dissolved at the same temperature and uniformly mixed for 5 minutes at 7000rmp. Then, the mixture was cooled to a temperature of 40 to 45°C, and then the vitamin C derivative, which is a main component, was dissolved and added thereto, followed by uniformly mixing at 7000 rpm for 5 minutes. Then, air bubbles were removed and cooled to prepare each cosmetic composition.

In Table 1 below, the components and contents of the cosmetic compositions of Example 1 and Comparative Examples 1 to 4, which are whitening cosmetic compositions containing 5.0% of a vitamin C derivative, are shown.

Ingredient (% by weight) Usage Example 1 Comparative Example 1 Comparative Example 2
Comparative Example 3 Comparative Example 4 Purified water solvent 75.88 80.48 75.48 74.98 75.48 Disodium EDTA Metal ion sequestering agent 0.02 0.02 0.02 0.02 0.02 Tromethamine pH adjuster 0.10 0.50 0.50 0.50 0.50 glycerin Moisturizer 10.00 10.00 10.00 10.00 10.00 Echil Ascorville Etel Vitamin C derivatives 5.00 - 5.00 5.00 5.00 Carbomer Thickener 0.50 - - - 0.50 Acrylate/C10-30 alkyl acrylate crosspolymer Thickener - 0.5 0.5 0.5 - C14-22 alcohol/C12-20 alkyl glucoside Surfactants 1.50 1.50 1.50 1.50 1.50 Neopentyl glycol dicaprate Oil component 3.00 3.00 3.00 3.00 3.00 Octyldodecanol Oil component 4.00 4.00 4.00 4.00 4.00 Benzotriazolyldodecyl p-cresol Discoloration inhibitor - - - 0.50 - Sum 100 100 100 100 100

Experimental Example 1. Measurement of hardness and confirmation of discoloration

The hardness of the prepared cosmetic composition was measured and described in Table 2 below. At this time, the hardness was measured by Rhetech's Fudoh Rheometer, and the measurement conditions were S.ADJ. 25, S.RANGE 1mm, RANGE 500, T.SPEED 2, STROKE 10mm. In addition, the pH meter was measured with ORION STAR A211 of Thermo scientific, and the measurement conditions were measured as purified water: emulsion = 15:1. The color change was checked by putting the contents in a certain amount in a transparent cream container and checking whether the color changed after one day of manufacture, and the results are shown in Table 2 and FIG. 1.

Experiment result Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Hardness value (Dyne/CM ² ) 30 30 15 15 25 pH (1:15) 4.5 6.5 5.8 5.8 5.8 Whether it is discolored X X O O O

As can be seen in Table 2 and FIG. 1, except for Example 1 and Comparative Example 1, all were discolored to yellow. Additionally, there was no change in color of the contents even when it was confirmed whether or not discoloration was observed after storing Example 1 at room temperature (25° C.) and high temperature (45° C.) for 1 month.

Experimental Example 2. Analysis of the content of vitamin C derivatives (confirmation of potency)

Content analysis was performed to see if the vitamin C derivative in the emulsion prepared according to Example 1 was not oxidized and maintained stably. After storage for 1 month at room temperature (25°C) and high temperature (45°C), it was analyzed by LC. The instrument was Agilent Technologies' 1260 Infinity II, and the test method is as follows.

A 3% methanol solution of the vitamin C derivative was used as a standard solution, and samples stored at RT and 45°C were dissolved in methanol in a certain amount to prepare a sample solution. The sample solution and the standard solution were tested according to the liquid chromatography method to calculate the content relative to the peak area, and are shown in Table 3 below.

Storage conditions RT 45℃ Analysis 5.0±0.5 5.0±0.5

As can be seen in Table 3, as a result of the analysis, it was confirmed that the content of the vitamin C derivative did not decrease in all storage conditions, but was detected in a certain amount and maintained stable.

Experimental Example 3. Evaluation of whitening efficacy

The whitening effect of the cosmetic composition prepared in Example 2 below was evaluated by improving skin brightness and skin transparency as follows, and the results of 5 adults (average age 28.4 years old) were calculated as an average to compare before and after use. I did. The product was used twice a day for 2 weeks. As a control product, a general whitening cosmetic composition prepared in Comparative Example 5 was used.

Ingredient (% by weight) Usage Example 2 Comparative Example 5 Purified water solvent 78.93 78.93 Disodium EDTA Metal ion sequestering agent 0.02 0.02 Tromethamine pH adjuster 0.05 0.05 glycerin Moisturizer 10.00 10.00 Echil Ascorville Etel Vitamin C derivatives 2.00 - Niacinamide Whitening ingredients - 2.00 Carbomer Thickener 0.50 0.5 C14-22 alcohol/
C12-20 alkyl glucoside Surfactants 1.50 1.50 Neopentyl glycol dicaprate Oil component 3.00 3.00 Octyldodecanol Oil component 4.00 4.00 Benzotriazolyldodecyl p-cresol Discoloration inhibitor - - Sum 100.00 100.00

3-1. Evaluation of the effect of improving skin brightness

After washing the test site with soap, wait in a constant temperature and humidity room (22±2, 40-60% PH) for 10 minutes, and then the brightness of the test site was measured with a spectrophotometer (KONICA MINOLTA) after 0 and 2 weeks. The average of the three measured values was calculated, compared with the measured value at week 0, and the results were shown in FIGS. 2 and 5.

L value increase/decrease (%, compared to week 0) Example 2 Comparative Example 5 Result 3.0 1.5

As can be seen in Figure 2 and Table 5, after 2 weeks of use of the cosmetic composition prepared in Example 2 (test product) and Comparative Example 5 (manufactured by control), the L value increase and decrease rate were about 3.0% and 1.5%, respectively. As it appeared, it was found that the test product prepared in Example 2 had excellent brightness improvement effect.

3-2. Efficacy evaluation for improving skin transparency

After washing the test site with soap, wait in a constant temperature and humidity room (22±2, 40-60% PH) for 10 minutes, and then the skin transparency of the test site was measured by Antera 3D (MIRAVEX) after 0 and 2 weeks. The average of the three measured values was calculated, compared with the measured value at week 0, and the results were shown in FIGS. 4A and 6. As the AREA value increases, it means that the total amount of light scattered into the skin increases, which means that the skin transparency is improved.

AREA (A.U) Example 2 Comparative Example 5 0 weeks 2 weeks 0 weeks 2 weeks Result 49603 50445 49147 48180

In addition, as can be seen in Figure 4b and Table 7, the test product prepared in Example 2 increased the AREA value to 1.7 after 2 weeks of use, resulting in improved skin transparency, whereas the control product had an AREA value of -2.0, improving skin transparency. It was found to have no effect.

Area change rate (%, compared to week 0) Example 2 Comparative Example 5 Result 1.7 -2.0

Claims (7)

An oil-in-water type whitening cosmetic comprising 1 to 30% by weight of a vitamin C derivative, 0.1 to 5.0% by weight of a pH adjuster, 0.1 to 5.0% by weight of a thickener, 1.0 to 20.0% by weight of an oil component, 0.1 to 5.0% by weight of a surfactant, and purified water Composition. The cosmetic composition of claim 1, wherein the vitamin C derivative is ethyl ascorbyl ether. The cosmetic composition of claim 1, wherein the pH adjusting agent is at least one selected from the group consisting of triethanolamine, tromethamine, sodium hydroxide, potassium hydroxide, aminomethylpropanol, and arginine. . The cosmetic composition of claim 1, wherein the thickener is a carbomer. The method of claim 1, wherein the oil component is caprylic/capric triglyceride, cetyl ethylhexanoate, cetylhexyl palmitate, neopentyl glycoldi Consisting of Caprate (Neopentyl Glycol Dicaprate), Triethylhexanoin, Hydrogenated Polydecene, Dimethicone, Cyclopentasiloxane, and Cyclohexasiloxane One or more selected from the group, the oil-in-water type whitening cosmetic composition. The cosmetic composition of claim 1, wherein the surfactant is a nonionic surfactant. The method of claim 6, wherein the nonionic surfactant is Polysorbate 60, Polyglyceryl-3 Methylglucose Distearate, Cetearyl Glucoside, C12- 20 Alkyl Glucoside (C12-20 Alkyl Glucoside), Cetearyl Olivate (Cetearyl Olivate), sorbitanolibate (Sorbitan Olivate) and PEG-100 Stearate (PEG-100 Stearate) at least one member selected from the group consisting of Phosphorus, an oil-in-water type cosmetic composition for whitening.

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