KR102312901B1 - Emulsified cosmetic composition with acidic pH comprising macro liquid crystal emulsion particle - Google Patents

Abstract

The present invention relates to an emulsified cosmetic composition having an acidic pH and comprising macro-sized liquid crystal emulsified particles. The emulsified cosmetic composition according to the present invention has the effect of stabilizing the acidic pH system to restore the skin barrier and strengthen the barrier function, improve skin troubles including acne and atopy, anti-aging, and normalize the skin enzyme function, and also It can strengthen moisture retention and effectively deliver active ingredients.

Description

Emulsified cosmetic composition with acidic pH comprising macro liquid crystal emulsion particles

The present invention relates to an emulsified cosmetic composition having an acidic pH and comprising macro-sized liquid crystal emulsified particles.

In general, a liquid crystal is an intermediate state between a solid and a liquid, which is usually organic molecules having a hydrophilic part and a lipophilic part at the same time. It refers to a system in which a lamellar structure, which is arranged to form several layers, is generated. Liquid crystal behaves like a liquid in terms of viscosity and fluidity, but in terms of physical properties such as scattering and reflection of light, it exhibits unique properties such as solid properties, and thus has a wide range of applications in cosmetics, pharmaceuticals, food and electronics industries. In the field of cosmetics and pharmaceuticals, liquid crystal is generated at the interface during the manufacture of emulsions to stabilize the emulsion, and by having a structure similar to that of biological cell membrane interlipids, it not only forms a skin barrier and moisturizes, but also preserves various water-soluble and useful medicinal ingredients. It is applied as an effective delivery medium for improving stability. For example, the production of liquid crystals of nonionic surfactant-cetostearyl alcohol is widely used in cosmetics. Such liquid crystals cause swelling in the emulsion system and have an effect of increasing the viscosity and hardness of the emulsion or cream.

On the other hand, normal skin pH (acidity) is weakly acidic, and weakly acidic skin pH is the activity of enzymes that maintain normal skin functions, such as serine protease and beta-glucocerebrosidase of the skin. There is a relation. It can be confirmed that the skin pH is higher than normal in most of the skin with problems including acne and atopic dermatitis as well as aging skin. It can be seen that the skin barrier is restored and the skin is normalized.

However, the acidic pH system is not compatible with the representative components constituting the cosmetic composition, particularly surfactants and thickeners, and phase separation occurs easily, so it is excellent in skin moisture and is advantageous for delivery of active ingredients. There is a problem that it is difficult to provide to users.

On the other hand, emulsified cosmetic compositions with large macro-sized particles can be visually differentiated to identify the emulsion particles, and the amount of oil contained in the emulsified particles is high, so it is possible to provide a feeling of use differentiated from existing micro-emulsions. . In addition, since the content of the emulsifier can be reduced, skin irritation and skin burden that may be caused by the emulsifier can be reduced, and there is an advantage of improving stability by collecting poorly soluble components with poor compatibility with water. However, coalescence or aggregation between the emulsified particles is easy to occur, so it is difficult to secure the stability of the composition.

Therefore, there is a need to develop a new formulation that has excellent stability, excellent moisturizing power, and less skin irritation by solving the above problems.

Journal of Investigative Dermatology, 2847-2856, 127, 2007 Journal of Investigative Dermatology, 1824-1835, 129, 2009

An object of the present invention is to solve the above problems, and to provide an emulsified cosmetic composition comprising macro-sized liquid crystal emulsified particles, which has excellent stability in acidic conditions, less skin irritation, and excellent feel.

As a means for solving the above problems, the present invention provides an emulsified cosmetic composition comprising liquid crystal emulsified particles having an acidic pH and having an average diameter of 2 to 30 μm.

The emulsified cosmetic composition according to the present invention stabilizes the acidic pH system to restore the skin barrier and strengthen the barrier function, and has the effect of improving skin troubles including acne and atopy, anti-aging, and normalizing the skin enzyme function, and also It can strengthen moisture retention and effectively deliver active ingredients.

Hereinafter, the configuration of the present invention will be described in detail.

The present invention provides an emulsified cosmetic composition comprising liquid crystal emulsified particles having an acidic pH and having an average diameter of 2 to 30 μm.

In one embodiment, the pH of the emulsified cosmetic composition may be 3 to 5. The pH of the cosmetic composition according to the present invention means the pH when measured by the pH test method among the cosmetic test methods, there is no skin irritation in the above range, and the effect of normalizing the pH of the skin is excellent. When the pH is less than 3, it may cause skin irritation, and when the pH exceeds 5, there is a problem that the effect of normalizing the pH change of the skin is weak.

The liquid crystal emulsified particles included in the emulsified cosmetic composition according to the present invention have an average diameter of a macro size of 2 to 30 μm. As can be seen in the following examples, within the above range, the application to the skin is uniform, and there is an advantage in that the user has an excellent feeling when using it. Conversely, when the average diameter is less than 2 μm, it is difficult to differentiate the appearance and feel by macro particles, and when the average diameter exceeds 30 μm, the application of the oil is not uniform, so it is not suitable for cosmetic application.

In one embodiment of the present invention, the emulsion cosmetic composition may have a viscosity of 2,000 to 8,000 cps, or a hardness of 12 to 50 dyne/cm ² . In the viscosity of the above range, the effect of normalizing the pH of the skin is excellent by alleviating the change in the pH of the skin. If the viscosity is less than 2,000 cps, there is a problem that the effect of normalizing the skin pH is weak. In addition, in the hardness of the above range, there is an advantage that the user's feeling of use is excellent. When the hardness exceeds 50 dyne/cm ² , there is a problem in that the feeling of use deteriorates.

In one embodiment of the present invention, the emulsified cosmetic composition may contain 0.5 to 7.0 w/w% of a higher fatty alcohol and 2.0 to 8.0 w/w% of a surfactant. When the above range is satisfied, the liquid crystal emulsified particles are stably well formed at an acidic pH, and there is an advantage in that the feeling of use is excellent. When it is out of the above range, there is a problem in that liquid crystal emulsified particles are not formed, or skin irritation occurs, or the feeling of use deteriorates.

In another embodiment of the present invention, the emulsified cosmetic composition may further include 10 to 30 w/w% of a polyol in addition to a higher fatty alcohol and a surfactant. By further including the polyol, the stability of the liquid crystal emulsified particles at acidic pH is improved, and there is an advantage in that the feeling is excellent.

In one embodiment, the higher fatty alcohol may be a fatty alcohol having 12 to 26 carbon atoms. The fatty alcohol having 12 to 26 carbon atoms is not limited thereto, but may be at least one selected from the group consisting of stearyl alcohol, cetyl alcohol, cetostearyl alcohol, and behenyl alcohol.

In one embodiment, the surfactant is selected from the group consisting of, but not limited to, methylglucose sesquistearate, polyglyceryl-3-methylglucose distearate, alkylglucoside, hydrogenated lecithin and glycerylstearate. There may be more than one.

In one embodiment, the polyol is selected from the group consisting of, but not limited to, glycerin, 1,3-butylene glycol, 1,2-hexanediol, dipropylene glycol, glycereth-26 and propylene glycol. There may be more than one.

In one embodiment of the present invention, the emulsified cosmetic composition may further include one or more thickeners selected from the group consisting of xanthan gum, hydroxyethyl cellulose, polyacrylate crosspolymer, and derivatives thereof. By further including a thickener, proper viscosity and/or hardness can be maintained.

The emulsified cosmetic composition of the present invention can be used for improving and alleviating various symptoms related to changes in the pH of the skin surface outside the normal range. For example, the emulsified cosmetic composition of the present invention stabilizes the acidic pH system to restore the skin barrier and strengthen the barrier function, and has the effect of improving skin troubles including acne and atopy, anti-aging, and normalizing the skin enzyme function, In addition, it can strengthen skin moisture retention and effectively deliver active ingredients. Therefore, the present invention shows an acidic pH and contains liquid crystal emulsified particles having an average diameter of 2 to 30 μm, and a cosmetic composition for skin improvement, such as strengthening skin barrier function, improving skin trouble, moisturizing skin and/or alleviating pH change. to provide. As can be seen in the following examples, the cosmetic composition of the present invention has excellent skin pH recovery, low skin irritation, excellent moisture retention, and excellent formulation stability.

Cosmetics prepared by containing the emulsified cosmetic composition of the present invention as an active ingredient may be prepared in the form of a general emulsified formulation or solubilized formulation. For example, a lotion (skin) such as a softening lotion or a nourishing lotion; emulsions such as facial lotions or body lotions; creams such as nourishing creams, moisturizing creams or eye creams; essence; makeup ointment; spray; gel; pack; sunscreen; makeup base; foundations such as liquid type, solid type or spray type; powder; makeup removers such as cleansing creams, cleansing lotions, and cleansing oils; It may have formulations such as cleansing foams, soaps, body washes, and the like. Preferably, the cosmetic composition of the present invention is not limited thereto, but may be applied to skin, essence, emulsion, cream, massage, pack, and the like.

In addition, the cosmetics include fatty substances, organic solvents, solubilizers, thickeners, gelling agents, emollients, antioxidants, suspending agents, stabilizers, foaming agents, fragrances, surfactants, water, ionic emulsifiers, nonionic emulsifiers , fillers, sequestering agents, chelating agents, preservatives, vitamins, blocking agents, wetting agents, essential oils, dyes, pigments, hydrophilic active agents, lipophilic active agents or lipid vesicles may contain adjuvants commonly used in the cosmetic field. .

Hereinafter, the present invention will be described in detail by way of Examples. However, the following examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following examples.

[ Example ]

Example 1 to 8

According to the composition of Tables 1 and 2 below, an oil phase and a surfactant phase were added and dissolved by heating at 70° C. to 75° C. to prepare a translucent liquid crystal emulsion system. An organic acid, a polyol, a thickener, etc. were dispersed in purified water and added to an aqueous phase heated to 70 to 75° C., followed by stirring for 10 minutes under the conditions of 1500 to 3500 rpm in a homomixer. After adding the additive at 50° C. and stirring for 5 minutes, it was cooled to 30° C. to prepare an emulsified cosmetic composition having liquid crystal emulsified particles exhibiting an acidic pH.

comparative example 1 to 8

According to the composition of Table 3 below, an oil phase and a surfactant phase were added and dissolved by heating at 70° C. to 75° C. to prepare a simple emulsion system. The oil phase was dispersed in purified water with an organic acid, a polyol and a thickener and added to an aqueous phase heated to 70 to 75° C., followed by stirring for 10 minutes under conditions of 1500 to 3500 rpm in a homomixer. Then, the additive was added at 50° C., stirred for 5 minutes, and cooled to 30° C. to prepare an emulsified cosmetic composition.

[ Experimental example ]

Experimental example 1: Check pH, liquid crystal emulsion particle formation, viscosity and hardness

The pH of the Examples and Comparative Examples, the presence or absence of liquid crystal emulsified particles, viscosity and hardness were checked. The pH was measured with an F-52 pH meter (HORIBA) by diluting 2 g of the sample with 30 ml of purified water according to the functional cosmetics test method.

The hardness was measured using an RTC-3005D hardness tester (RHEOTECH) when the measuring bar pressed the sample to a depth of 25 mm at a speed of 2 cm/min.

The presence or absence of the formation of liquid crystal emulsified particles was confirmed by observing the particles with an optical microscope (Leica DM RP) using a polarizing filter, and observing whether the liquid crystal structure had a characteristic cross structure. The results are shown in Tables 4 and 5 below.

Experimental example 2: Comparison of skin pH recovery according to formulation

In order to compare the skin pH change mitigation effect and durability according to the type of formulation, Examples 1 to 4 of different formulations, and the compositions of Comparative Examples 1 and 2 were used. In a constant temperature and humidity room maintained at a temperature of 25℃ and a relative humidity of 70%, the skin pH was measured immediately before the experiment on 20 healthy adult men and women, and the skin pH immediately after washing with a foam cleanser of pH 10 to artificially increase the skin pH. was measured, and after each formulation was applied, the skin pH was measured in units of 10 minutes up to 60 minutes and compared with the average value. User satisfaction was confirmed through a questionnaire on a 5-point scale after the end of the experiment. Skin pH was measured using a skin pH measuring device (Skin-pH-Meter PH905, Courage + Khazaka electronic GmbH), and the results are shown in Table 6 below.

As can be seen from the results of Table 6, in the case of Examples 1, 3, and 4, it can be confirmed that the skin pH is quickly normalized, and in the case of Example 2, the skin pH is normalized relatively quickly, although somewhat late. can be checked However, in the case of Comparative Example 1, it can be seen that even after 60 minutes after applying the formulation, the pH was not restored to the pre-experimental pH. In addition, in the case of Comparative Example 2, it can be confirmed that the use satisfaction is low due to the heavy feeling of high hardness. Accordingly, it is important to select an appropriate emulsifier type such as lotion, essence, cream, etc. for skin pH recovery, and a viscosity within an appropriate range (2,000 to 8,000 cps) or hardness within an appropriate range (12 to 50 dyne/cm2) rather than a low-viscosity skin type. ) was found to be important to maintain.

Experimental example 3: Comparison of pH recovery and skin irritation according to organic acid concentration

In order to examine the skin pH recovery ability and skin irritation, the concentration of organic acid was adjusted to prepare the products of Examples 1 and 5 to 6 and Comparative Examples 3 to 4 of the same formulation having different pH. In a constant temperature and humidity room maintained at a temperature of 25℃ and a relative humidity of 70%, the skin pH was measured immediately before the experiment on 20 healthy adult men and women, and the skin pH immediately after washing with a foam cleanser of pH 10 to artificially increase the skin pH. was measured, and after each formulation was applied, the skin pH was measured in units of 10 minutes up to 60 minutes and compared with the average value. The skin irritation level was measured using a 24-hour patch test based on Cosmetic Evaluation/Analysis Method Evaluation-29, and the irritation index was as follows.

User satisfaction was confirmed through a questionnaire on a 5-point scale after the end of the experiment. Skin pH was measured using a skin pH measuring device (Skin-pH-Meter PH905, Courage + Khazaka electronic GmbH), and the results are shown in Table 7.

As can be seen from the results of Table 7, in the case of Examples 1, 5 and 6, it can be confirmed that the skin pH is quickly restored, but in the case of Comparative Example 4, the pH before the experiment even after 60 minutes after applying the formulation It can be seen that recovery is not possible. In addition, it was found that Comparative Example 3 has a high degree of skin irritation, which may cause irritation to the user's skin when used as a cosmetic.

This means that it is very important to maintain the pH in an appropriate range.

Experimental example 4: Formulation stability, moisture depending on whether liquid crystal emulsified particles are formed holding capacity and customer satisfaction comparison

In order to compare formulation stability, water retention ability, and customer satisfaction according to the presence or absence of liquid crystal emulsified particles, the compositions of Example 1 and Comparative Example 5 were used with differences in the formation of liquid crystal emulsified particles by changing the content of fatty alcohol and surfactant. . The skin moisture content was measured before the test on an area of 3 cm x 3 cm in the inner forearm of 20 healthy adult male and female subjects, and the skin moisture content was measured every week while applying the sample for 4 weeks. The skin moisture content was measured using a skin moisture content measuring device (Corneometer CM825, CK Electronic, Germany) in a constant temperature and humidity room maintained at a temperature of 25° C. and a relative humidity of 70%, and compared with the improvement rate before the test. In addition, the same subject was asked to use the cream on the face as usual for 4 weeks, and the satisfaction with use was confirmed through a questionnaire on a 5-point scale. To check the stability of the formulation, it was placed in a transparent container and stored in a chamber at 25°C, 50°C, 0°C, Cycle (-15°C ~ 45°C), and then phase separation was confirmed. The results are shown in Tables 8 and 9 below.

As can be seen from the results of Table 8, Example 1 in which the liquid crystal emulsified particles were formed has excellent skin moisture content improvement compared to Comparative Example 5 in which the liquid crystal emulsified particles are not formed, and thus it can be confirmed that the customer satisfaction is also high. In addition, as can be seen from the results of Table 9, it can be confirmed that the liquid crystal emulsified particles improve the stability of the emulsified cosmetic composition having an acidic pH. Accordingly, it was found that the content of the surfactant and the formation of liquid crystal emulsified particles are important.

Experimental example 5: polyol Comparison of stability and customer satisfaction of liquid crystal emulsified particles according to content

In order to compare the stability and customer satisfaction of the liquid crystal emulsified particles according to the polyol content, the compositions of Examples 1, 7, 8 and Comparative Example 6 having a difference in the polyol content were used. Twenty healthy adult men and women were asked to use the cream on their face as usual, and after 4 weeks, their satisfaction with use was confirmed through a questionnaire on a 5-point scale. To check the stability of the formulation, it was placed in a transparent container and stored in a chamber at 25°C, 50°C, 0°C, Cycle (-15°C ~ 45°C), and then phase separation was confirmed. The results are shown in Table 10 below.

As can be seen from the results of Table 10, it can be confirmed that the content of the polyol affects the maintenance of the liquid crystal emulsified particles and the feeling of satisfaction. Thus, it can be seen that the content of the polyol is very important.

Experimental example 6: Comparison of skin irritation and customer satisfaction according to liquid crystal emulsion particle size

In order to compare the stability of the formulation according to the liquid crystal emulsion particle size, skin irritation, and customer satisfaction, the compositions of Examples 9, 10, Comparative Examples 7 and 8, which have minute differences in surfactant content and composition, were used. A 24-hour patch test was conducted on 20 healthy adult male and female subjects in a constant temperature and humidity room maintained at a temperature of 25℃ and a relative humidity of 70% based on the Cosmetic Evaluation/Analysis Method Pyeong-29. The irritation index is as follows. .

Satisfaction with the use of the cream was confirmed through a questionnaire on a 5-point scale after 4 weeks of using the cream on the face as usual.

The results are shown in Table 11.

As can be seen from the results of Table 11, it can be seen that the satisfaction with skin softness increases as the average particle size increases, and thus, it can be confirmed that the use satisfaction also increases. Compared to Example 1, as the average particle size is relatively large, the feeling of use of the oil increases, and a feeling of skin heterogeneity such as shine is much felt. feel the

Therefore, it was found that an appropriate particle size is very important in terms of satisfaction and skin irritation when using cosmetics.

Claims (9)

It has a pH of 3 to 5 and contains liquid crystal emulsified particles having an average diameter of 2 to 30 μm,
0.5 to 7.0 w/w% of a higher fatty alcohol, 2.0 to 8.0 w/w% of a surfactant, 10 to 30 w/w% of a polyol, and an organic acid as a pH adjuster with respect to the entire emulsified cosmetic composition,
An emulsified cosmetic composition having a viscosity of 2,000 to 8,000 cps, or a hardness of 12 to 50 dyne/cm ^{2 .}
The emulsified cosmetic composition according to claim 1, wherein the higher fatty alcohol is a fatty alcohol having 12 to 26 carbon atoms.
The emulsified cosmetic according to claim 1, wherein the surfactant is at least one selected from the group consisting of methyl glucose sesquistearate, polyglyceryl-3-methylglucose distearate, alkylglucoside, hydrogenated lecithin, and glyceryl stearate. composition.
The emulsified cosmetic according to claim 1, wherein the polyol is at least one selected from the group consisting of glycerin, 1,3-butylene glycol, 1,2-hexanediol, dipropylene glycol, glycereth-26 and propylene glycol. composition.
According to claim 1,
An emulsified cosmetic composition further comprising one or more thickeners selected from the group consisting of xanthan gum, hydroxyethyl cellulose, polyacrylate crosspolymer, and derivatives thereof. delete delete delete delete