KR20160109868A - Emulsified cosmetic composition having a pH buffer system - Google Patents

Abstract

The present invention relates to an emulsified cosmetic composition having a pH buffer system. According to the present invention, the cosmetic composition having a pH buffer system shows reduced stimulation by organic acid, continuously relieves the change of skin pH due to internal/external causes, and significantly improves the conditions of skin with problems such as aging, acne, and atopic dermatitis, through the improvement of skin barriers and the exfoliating of dead skin cells.

Description

[0001] The present invention relates to an emulsified cosmetic composition having a pH buffer system,

The present invention relates to an emulsified cosmetic composition having a pH buffering system.

In general, the pH (acidity) of the skin is mildly acidic, and the weakly acidic skin pH is related to the activity of enzymes that maintain normal skin function, such as serine protease and beta-glucocerebrosidase . It can be confirmed that most of the skin including troubles such as acne and atopy has a higher skin pH than the aged skin, and according to the prior arts 1 and 2, atopic skin and aged skin are treated with a low pH substance The skin barrier is restored and the skin is normalized.

However, in the case of the conventional acidic pH system, there is a problem that it may cause skin irritation when it is applied to skin damaged or sensitized due to atopy or trouble, and it is difficult to improve the skin condition because the effect is temporary, There is a problem that is difficult to provide.

Organic acid loosens the strands of the stratum corneum and helps to exfoliate excess keratin. Generally, the skin stratum corneum protects the skin from physical and chemical factors. It can keep the skin clean and clear all the time through the continuous production of skin cells and turn over which is caused by peeling in the stratum corneum. have. However, due to environmental factors such as aging, ultraviolet rays, or stress, natural keratin detachment is delayed, and when the keratin is accumulated, the skin glossiness is reduced, and skin troubles such as acne can be accelerated. Alpha hydroxy acids, beta hydroxy acids, polyhydroxy acids and the like are known as organic acids promoting the exfoliation of the skin.

However, when the organic acid is applied to the skin as it is, there is a problem that it may cause skin irritation, so that there is a problem that it is difficult to provide the effect desired by the consumer in sensitive skin and troublesome skin.

Accordingly, there is a need for a novel formulation that can solve the above problems, reduce irritation caused by organic acids, and continuously alleviate changes in skin pH due to internal / external causes.

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

It is an object of the present invention to provide a cosmetic composition for emulsification having a pH buffering system which is less irritating by organic acids and can continuously alleviate changes in skin pH due to internal / external causes.

As means for solving the above problems, the present invention provides an emulsified cosmetic composition having a pH buffer system.

In the present invention, the pH buffer system is characterized in that it comprises a buffer solution containing an acid.

Accordingly, the present invention provides a cosmetic composition comprising a buffer solution containing an acid and having a pH of 3 to 5. [

As another means for solving the above problems,

The present invention provides a cosmetic composition comprising a buffer solution containing an acid and having a pH of 3 to 5 for alleviating skin moisturization and skin pH change.

The cosmetic composition with a pH buffer system according to the present invention is less irritating by organic acids, and continuously alleviates changes in skin pH due to internal / external causes, as well as aging, acne and atopy through exfoliation and skin barrier improvement It is possible to remarkably improve the trouble state of the skin.

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

The present invention provides an emulsified cosmetic composition having a pH buffer system.

In the present invention, the pH buffer system is characterized in that it comprises a buffer solution containing an acid.

Accordingly, the present invention provides an emulsified cosmetic composition comprising a buffer solution containing an acid and having a pH of 3 to 5. [

The emulsified cosmetic composition of the present invention is not particularly limited as long as it is an emulsion which is a mixture of two or more liquids which are not well fused. For example, the emollient cosmetic composition of the present invention may be of oil in water (O / W) or water in oil (W / O) type. It is also possible to use multiple emulsion types such as water in oil in water (W / O / W) or oil in water in oil (O / W / O).

In one embodiment, the emollient cosmetic composition of the present invention may be of the submerged type. The underwater type emulsion cosmetic composition is characterized in that an oil phase composed of oil and wax forms an emulsion structure by a surfactant molecule having both hydrophilic and lipophilic properties in the molecule and is dispersed in water phase composed of purified water, polyol, Compared to solubilized formulations, they have excellent moisture retention and skin abundance, which is advantageous for continuous improvement of skin including trouble such as atopy.

A buffer solution is a solution in which the pH of the solution is kept constant by keeping the hydrogen ion concentration constant without being greatly affected by the addition of a certain amount of acid or base from the outside. The buffer solution of the present invention contains an acid so that the pH of the entire cosmetic composition can be maintained at 3 to 5.

In the present invention, the pH range refers to the pH measured by the pH test method in the cosmetic test method, and the cosmetic composition of the present invention has a pH of 3 to 5. If the pH is less than 3, it may cause skin irritation. If the pH is more than 5, the effect of alleviating the skin pH change is insufficient.

In one example of the present invention, the acid may be contained in an amount of 0.1 to 3.0 parts by weight based on 100 parts by weight of the total composition. When the content of the acid satisfies the above range, the pH of the composition can be maintained at a pH of 3 to 5 continuously without irritation to the skin.

In one embodiment, the buffer solution comprises an organic acid and its conjugated base, or may comprise an organic acid and a pH adjusting agent. By including an organic acid and its conjugated base, or an organic acid and a pH adjusting agent, the pH can be kept constant.

In one embodiment, the organic acid is selected from the group consisting of citric, lactic, malic, glycolic, tartaric, salicylic, acetic, propionic, gluconolactone, lactobionic, mixtures thereof and derivatives thereof, Or more.

In one embodiment, the pH adjusting agent can be used without limitation as long as it can maintain the pH of the composition at a pH of 3 to 5. [ The pH adjusting agent may be selected from known buffers without limitation, for example, tromethamine, HEPES (4- (2-hydroxyethyl) -1-piperazineethanesulfonic acid), HEPPS (3- [4- (2-hydroxyethyl) -1-yl] propane-1-sulfonic acid), TAPS (3 - [[1,3-dihydroxy-2- (hydroxymethyl) propan- (2-hydroxyethyl) propane-2-yl] amino] ethanesulfonic acid), BES (N-morpholino) ethanesulfonic acid), TES (2 - [[ 2-aminoethanesulfonic acid), TAPSO (3 - [[1,3-dihydroxy-2- (hydroxymethyl) propan-2-yl] amino] -2-hydroxypropane- 2-hydroxypropanesulfonic acid), HEPPSO (N- (hydroxyethyl) piperazine-N'-2-hydroxypropanesulfonic acid), DIPSO (3- acid, glycinamide, Bicine, Tricine, Acetamidoglycine, MOPS (3-morpholinopropane-1-sulfonic acid), mixtures thereof and derivatives thereof It may be at least one selected from the group consisting of.

In one embodiment, the organic acid and its conjugate base may be included in a weight ratio of 1: 0.2 to 1: 1. When the content of the organic acid and its conjugated base is within the above range, the pH of the composition can be maintained at a pH of 3 to 5 continuously without irritation to the skin.

In one embodiment, the organic acid and the pH adjusting agent may be included in a weight ratio of 1: 0.2 to 1: 1. When the content of the organic acid and the pH adjuster satisfies the above range, the pH of the composition can be maintained at a pH of 3 to 5 continuously without irritation to the skin.

As can be seen from the following Examples, the emulsified cosmetic composition of the present invention has excellent skin moisturizing effect and can continuously alleviate changes in skin pH. It is possible to improve the water retention ability of the skin and alleviate the pH synergy of the skin caused by internal / external causes and maintain the skin in the normal range of pH 3 to 5, thereby alleviating various skin symptoms due to the pH change . For example, it can smooth skin texture, alleviate skin aging, acne, and atopic symptoms. In addition, the user's satisfaction with the use can be improved as the skin irritation is significantly lowered. Therefore, the cosmetic composition of the present invention can be provided as a formulation of a cosmetic for moisturizing skin and alleviating pH change.

The cosmetics prepared by containing the emulsified cosmetic composition of the present invention as an active ingredient can be prepared in the form of a general emulsified formulation or a solubilized formulation. For example, lotions (skins) such as soft lotion or nutrition lotion; Lotion such as facial lotion or body lotion; Creams such as nutritional creams, moisture creams or eye creams; essence; Makeup ointment; spray; Gel; pack; Sunscreen; Makeup base; A foundation such as a liquid type, a solid type or a spray type; powder; Makeup removers such as cleansing creams, cleansing lotions, cleansing oils; Detergents such as cleansing foams, soaps, body wash, and the like.

The cosmetic composition may further contain at least one selected from the group consisting of fatty substances, organic solvents, solubilizers, thickening agents, gelling agents, softening agents, antioxidants, suspending agents, stabilizers, foaming agents, fragrances, surfactants, water, Such as fillers, sequestering agents, chelating agents, preservatives, vitamins, blocking agents, wetting agents, essential oils, dyes, pigments, hydrophilic active agents, lipophilic active agents or lipid vesicles .

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

[ Example ]

Example  1 to 3

Oil, wax and a surfactant were added according to the composition shown in the following Table 1 and heated to dissolve at 70 캜 to 75 캜 to prepare an oil phase. Organic acids and their conjugate bases, or organic acids and organic buffer compounds were used as pH buffer solutions. pH buffer solution, polyol and thickeners were dispersed in purified water and the oil phase was added to the water phase heated to 70 to 75 ° C. Thereafter, the homomixer was stirred for 10 minutes under the condition of 1500 to 3500 rpm, and the additive was added at 50 占 폚. Then, the mixture was stirred for 5 minutes and cooled to 30 캜 to prepare an underwater type emulsion cosmetic composition having a pH buffer system.

Comparative Example  1 to 6

An underwater type cosmetic composition without a pH buffer system was prepared in the same manner as in Examples 1 to 6 according to the composition shown in Table 2 below.

[ Experimental Example ]

Experimental Example  1: Check pH and hardness

The pH and hardness of the above Examples and Comparative Examples were confirmed. The pH was measured by the pH test method in the cosmetic test method. In summary, 2 g of each of the compositions of the Examples and Comparative Examples was diluted with 30 ml of purified water, and the pH was measured using an F-52 pH meter (HORIBA) according to the functional cosmetic test method.

The hardness was measured by using a RTC-3005D durometer (RHEOTECH), and the resistance of the sample when the sample was pressed at a depth of 25 mm at a rate of 2 cm / min was measured. The results are shown in Table 3.

Experimental Example  2: Comparison of skin pH change and persistence according to pH buffer system type and presence

The compositions of Examples 1 to 3 and Comparative Examples 1 to 2 were used to compare the skin pH change relieving effect and the sustainability depending on the type and the presence of the pH buffer system. 20 men and women undergoing mild atopy in a temperature and humidity room maintained at 25 ℃ and 70% relative humidity were used to measure the skin pH of the lesion immediately before the experiment. To increase the skin pH artificially, a foam cleanser The skin pH was measured immediately after cleansing the lesion. After each formulation was applied, the skin pH was measured up to 240 minutes in 30-minute increments and compared with the average value. Skin pH was measured using a skin pH meter (Skin-pH-Meter PH905, Courage + Khazaka electronic GmbH), and the results are shown in Table 4.

As can be seen from the results of Table 4, it can be confirmed that the skin pH is rapidly normalized in Examples 1 and 2 and maintained for the measurement time. In the case of Example 3, the skin pH was maintained normalized for up to 180 minutes due to the difference in buffer capacity. However, in the case of Comparative Example 1, it was confirmed that the pH did not recover before the experiment even after 120 minutes from the application of the formulation. In the case of Comparative Example 2, the pH was recovered quickly after the formulation was applied. .

This means that the cosmetic composition of the present invention has a pH buffer system, thereby continuously alleviating the pH change of the skin.

Experimental Example  3: With or without pH buffer system Skin texture , Exfoliation  Improvement, skin moisture retention ability and skin irritation

In order to compare the skin effect, the improvement of the skin exfoliation and the skin moisturizing effect according to the presence or absence of the pH buffer system, Example 1 and Comparative Examples 1 to 6 in which buffer systems were different were used. Twenty adults in their 50s were tested for skin texture and skin pH just before the experiment. The cream was applied to the face for 4 weeks according to the usual method.

Satisfaction with use was confirmed by questionnaire with 4 out of 5 points. The change of skin texture was measured using a PRIMOS High Resolution Image Analyzer in a constant temperature and humidity room maintained at 25 ℃ and 70% relative humidity.

The improvement of the exfoliation was evaluated by comparing the Luminosity value of the test area with that of the test site after using the DHA (Chromameter CR300, Germany CK Electronic).

Skin moisture content was measured using a skin moisture content measuring device (Corneometer CM825, CK Electronic, Germany). The results were compared with the improvement rate before the test.

Skin irritation test was conducted for 24 hours on the basis of Cosmetics Evaluation / Analysis Method-29. The stimulus index (PII) was as follows.

The results are shown in Table 5 below.

As can be seen from the results of Table 5, Example 1 having a pH buffer system exhibited remarkable skin texture improvement, skin moisture content improvement and exfoliation improvement as compared with Comparative Examples 1 to 6, .

In Comparative Examples 2 to 5, the skin texture, the skin moisture content and the exfoliation were somewhat improved but the degree was remarkably low. In Comparative Example 4 and Comparative Example 6, skin irritation was high and it was not suitable for sensitive skin users. It was also able to identify coming out low.

This means that the pH buffer system of the present invention is effective for skin texture improvement, skin moisture content improvement, and exfoliation improvement. It also means that the concentration of the organic acid contained in the pH buffer system and the ratio of the organic acid and its conjugate base or the content of the organic buffer compound are important for maintaining the above effect continuously.

Experimental Example  4: With or without pH buffer system Percutaneous  Water loss ( TEWL ), Improvement of atopy and satisfaction of use

In order to compare the skin barrier restoration and symptom improvement efficacy of atopic dermatitis with or without a pH buffer system, Example 1 and Comparative Examples 1 to 4, which are different from the buffer system, were used.

Twenty men and women suffering from mild atopy were examined for percutaneous water loss immediately before the experiment and the cream was used for 4 weeks at the affected site as usual. The transdermal water loss was measured every 2 weeks using a Tewameter (TM300, Germany CK Electronic) in a constant temperature and humidity chamber maintained at a temperature of 25 ° C and a relative humidity of 70%.

The improvement of atopic symptoms was visualized by visual confirmation, and it was confirmed by the questionnaire with the scale of 5 points after 4 weeks of use.

Satisfaction with use was confirmed by questionnaire with 4 out of 5 points.

The results are shown in Table 6.

As can be seen from the results of Table 6, Example 1 having the pH buffer system showed a skin barrier improvement effect and an atopic symptom improvement effect, which were measured by a remarkable transdermal water loss (TEWL) as compared with Comparative Examples 1 to 4. It can be confirmed that the ratio of atopy-improved persons in Example 1 was remarkably high, and the atopy improvement satisfaction and the use satisfaction were also high. In the case of Comparative Examples 2 to 4, the amount of transdermal water loss and visual symptom improvement were noticed to some extent, but the degree was remarkably low.

This means that the pH buffer system of the present invention is excellent in skin barrier improvement effect and atopic symptom improvement effect and can be used for skin barrier improvement and atopic symptom relief. It was also found that the concentration of the organic acid contained in the pH buffer system and the ratio of the organic acid and its conjugate base or the content of the organic buffer compound are important for maintaining the above effect continuously.

Claims (8)

1. A cosmetic composition for emulsification comprising a buffer solution containing an acid and having a pH of 3 to 5.
The method according to claim 1,
Wherein the acid is contained in an amount of 0.1 to 3.0 parts by weight based on 100 parts by weight of the total composition.
The method according to claim 1,
Wherein the buffer solution comprises an organic acid and its conjugated base.
The method according to claim 1,
Wherein the buffer solution comprises an organic acid and a pH adjusting agent.
The method according to claim 2 or 3,
Wherein the organic acid is at least one selected from the group consisting of citric acid, lactic acid, malic acid, glycolic acid, tartaric acid, salicylic acid, acetic acid, propionic acid, gluconolactone, lactobionic acid, mixtures thereof and derivatives thereof.
The method of claim 3,
The pH adjusting agent may be selected from the group consisting of tromethamine, HEPES (4- (2-hydroxyethyl) -1-piperazineethanesulfonic acid), HEPPS (3- [4- (2- (N-morpholino) ethanesulfonic acid), TES (2- [3-amino- 2-aminoethanesulfonic acid), BES (N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid), TAPSO (3 - [[ , 2-hydroxypropanesulfonic acid), POPSO (Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid)), HEPPSO (N - (Hydroxyethyl) piperazine-N'-2-hydroxypropanesulfonic acid), DIPSO (3- (N-Bis [2- hydroxyethylamino] -2- hydroxypropanesulfonic acid, glycinamide, Bicine) , At least one selected from the group consisting of tricine, acetamidoglycine, 3-morpholinopropane-1-sulfonic acid (MOPS), mixtures thereof, and derivatives thereof. / RTI >
3. The method of claim 2,
Wherein the organic acid and its conjugated base are contained in a weight ratio of 1: 0.2 to 1: 1.
The method of claim 3,
Wherein the organic acid and the pH adjusting agent are contained in a weight ratio of 1: 0.2 to 1: 1.