WO2025226072A1 - Transparent cosmetic composition having high azelaic acid content - Google Patents

Abstract

The present invention relates to a transparent liquid-type cosmetic composition containing an azelaic acid and a sodium base, and having a high azelaic acid content. A transparent liquid-type cosmetic composition according to the present invention not only has a high azelaic acid content due to including a sodium base, an amino acid, and a polyol that increase the solubility of azelaic acid, but is also optimized for troubled skin, provides a refreshing feeling, and has a skin moisture improvement effect.

Description

Transparent cosmetic composition containing a high content of azelaic acid

This patent application claims priority to Republic of Korea Patent Application No. 10-2024-0055940, filed with the Korean Intellectual Property Office on April 26, 2024, the disclosure of which is incorporated herein by reference.

The present invention relates to a transparent liquid type cosmetic composition containing azelaic acid and a sodium base, and more particularly, to a transparent liquid type cosmetic composition containing azelaic acid in a high content, including a sodium base, an amino acid, and a polyol that increase the solubility of azelaic acid.

Azelaic acid has been used to alleviate a wide range of physiological and chronic conditions, including acne, pigmentation, hair loss, wrinkles, hyperhidrosis, inflammatory skin diseases, and infectious skin diseases.

Currently known formulations of azelaic acid are dispersion formulations, which deliver azelaic acid in an undissolved state. Undissolved azelaic acid is not readily absorbed when applied to the skin, and as a result, an excessive amount of azelaic acid is required to exhibit an effect.

Therefore, a fully dissolved azelaic acid composition is required, as dissolved azelaic acid is more readily absorbed than the undissolved form and is therefore less irritating to the skin, thus reducing the risk of adverse skin irritation effects.

Although azelaic acid is somewhat soluble in water, cosmetic oils, and alcohols, each of these solvents has significant limitations. Water can only dissolve azelaic acid in very small amounts, so a solution containing water and azelaic acid can contain only about 0.24% by weight (w/w) of azelaic acid, which is insufficient to be effective. Furthermore, azelaic acid is also poorly or completely soluble in cosmetic oils. Furthermore, while alcohol is a good solvent, the presence of large amounts of isopropyl alcohol in topical compositions can negatively affect the skin, hindering its effectiveness. In fact, some alcohols, such as ethyl alcohol, tend to destabilize azelaic acid under standard temperature and atmospheric pressure conditions, making it difficult to formulate cosmetic compositions that are effective on the skin as a whole.

Accordingly, an emulsion containing 10-20% azelaic acid in a concentration based on water, apple pectin and sunflower oil was published in the literature by Berova et al. (Berova, N., et al., in Hypoallergic Cosmetic Emulsion with Azelaic Acid for Prophylaxy and Treatment of Acne Vulgaris, Berova, N., Nkiolova, A., Kratchanov, Chr., and Popova, M., Journal of Applied Cosmetology, vol. 12, no. 3, p. 51 (1994)), and Berova et al. attributed the less irritating nature of their formulation to the use of natural ingredients such as apple pectin and sunflower oil instead of non-natural substances as the azelaic acid vehicle. However, since the emulsion disclosed by Veroba et al. has incompletely dissolved azelaic acid, the weight percentage of azelaic acid in the formulation is much higher than that required for a cosmetic composition.

To produce a commercially viable product containing dissolved azelaic acid, the formulation must remain stable under standard temperature and atmospheric pressure conditions; however, the art has not yet developed a cosmetic composition that is stable and completely dissolves azelaic acid under standard temperature and atmospheric pressure conditions.

Accordingly, research is needed on a transparent liquid type cosmetic composition that increases the solubility of azelaic acid, contains a high content of azelaic acid, and provides a refreshing feeling without side effects.

Against this backdrop, the inventors of the present invention have conducted extensive research on a cosmetic composition with increased solubility of azelaic acid, and have confirmed that a transparent liquid type cosmetic composition containing azelaic acid, sodium chloride, amino acid, and polyol contains a high content of azelaic acid, is optimized for troubled skin, and exhibits a refreshing feeling as well as an excellent skin moisture improvement effect.

Accordingly, the purpose of the present invention is to provide a transparent liquid type cosmetic composition containing azelaic acid and a sodium base.

Another object of the present invention is to provide a composition for external application to the skin comprising azelaic acid and a sodium salt.

Another object of the present invention is to provide a method for producing a transparent liquid type cosmetic composition or composition for external application to the skin containing a high content of azelaic acid, comprising the following steps:

A step of preparing a first mixture by mixing purified water and a thickening agent;

A step of preparing a second mixture by dissolving azelaic acid in a solvent under heating;

A step of preparing a third mixture by mixing purified water and sodium base; and

A step of preparing a composition by mixing the first mixture and the second mixture and then mixing the third mixture.

Another object of the present invention is to provide a transparent liquid type cosmetic composition that contains azelaic acid and a sodium base and a high content of azelaic acid, and is optimized for skin troubles and exhibits a refreshing feeling and an excellent skin moisture improvement effect.

Another object of the present invention is to provide a cosmetic composition comprising azelaic acid, sodium base and amino acid.

Another object of the present invention is to provide a cosmetic composition comprising azelaic acid, sodium base and polyol.

The present invention relates to a transparent liquid type cosmetic composition containing azelaic acid and a sodium salt, and the inventors of the present invention have completed the present invention by confirming that the transparent liquid type cosmetic composition not only contains azelaic acid in a high content by including a sodium salt, an amino acid, and a polyol that increase the solubility of azelaic acid, but also exhibits a refreshing feeling optimized for troubled skin, an excellent skin moisture improvement effect, and a significant anti-acne effect.

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

One aspect of the present invention is a high-azelaic acid cosmetic composition comprising azelaic acid and a sodium base.

In the present invention, the cosmetic composition is a liquid, gel, cream, lotion, paste, emulsion, dispersion, foam, toner, skin, toner, serum, essence, eye cream, nourishing cream, massage cream, hand cream, ointment, external ointment for skin, liquid soap, solid soap, scrub, detergent, cleansing foam, cleansing gel, cleansing lotion, cleansing cream, cleansing water, cleansing oil, body cleanser, body lotion, patch, mask, pack, shampoo, rinse, conditioner, treatment, hair pack, hair tonic, hair fixer stick, scalp ampoule, sunscreen, sunscreen, BB cream, CC cream, tone-up cream, makeup base, makeup primer, foundation, pact, concealer, powder, spray, atomizer, aerosol, eye shadow, eyebrow, eyeliner, balm, stick, sun stick, It may be one or more formulations selected from the group consisting of highlighter sticks, contour sticks, lip balms, lipsticks, lip tints, lip glosses, lip oils, lip lacquers, lip creams, and lip crayons, but is not necessarily limited thereto.

In one embodiment of the present invention, the cosmetic composition may be a transparent formulation. In another embodiment of the present invention, the cosmetic composition may be a liquid formulation. In yet another embodiment of the present invention, the cosmetic composition may be a transparent liquid formulation.

The term "azelaic acid" used herein refers to an organic substance having a structure represented by the following chemical formula 1, which can be used as a precursor for various products, including polymers and plasticizers, as well as a component of hair and skin conditioner compositions. Azelaic acid is also known to be effective in treating acne and can be used as a whitening agent for freckles and inflammatory pigmentation.

[Chemical Formula 1]

The term "sodium base" in this specification may be used interchangeably with "sodium salt" and means a compound that includes sodium (Na) within the compound.

The term "amino acid" in this specification means an organic compound having an amino group (in the form of -NH3 ⁺ , which is protonated under biological conditions), a carboxyl group (in the form of -COO ^- , which is deprotonated under biological conditions) and a specific side chain (R group), and also includes amino acid derivatives.

The term "amino acid derivative" as used herein refers to a compound derived from an amino acid by replacing, adding, or removing an amino group, carboxyl group, side chain group, or other group attached to a central atom of the amino acid. For example, betaine is a trimethylated derivative of the amino acid glycine, which is an amino acid derivative containing a glycine backbone with three methyl groups attached to the nitrogen atom. The amino acid derivative of the present invention may include, but is not necessarily limited to, any one or more of betaine, betaine salicylate, glycocyamine, acetylcysteine, sodium PCA, glycolic acid, and lactic acid.

In the present invention, the cosmetic composition may contain azelaic acid in an amount of 0.1 to 30 wt%, 0.1 to 25 wt%, 0.1 to 20 wt%, 0.2 to 30 wt%, 0.2 to 25 wt%, 0.2 to 20 wt%, 0.3 to 30 wt%, 0.3 to 25 wt%, 0.3 to 20 wt%, 0.4 to 30 wt%, 0.4 to 25 wt%, 0.4 to 20 wt%, 0.5 to 30 wt%, or 0.5 to 25 wt%, based on the total cosmetic composition, and for example, may contain 0.5 to 20 wt%, but is not limited thereto.

In one embodiment of the present invention, the cosmetic composition may contain the azelaic acid in an amount of 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 5 to 20 wt%, 5 to 15 wt%, 5 to 10 wt%, 10 to 20 wt%, 10 to 15 wt%, or 15 to 20 wt%, for example, but not limited to, 10 to 15 wt%, 10 to 16 wt%, or 10 to 17 wt%.

In the present invention, the sodium base may include at least one selected from the group consisting of sodium hydroxide, sodium citrate, and sodium carbonate, but is not limited thereto.

In the present invention, the cosmetic composition may contain the sodium base in an amount of 0.05 to 30 wt%, 0.05 to 28 wt%, 0.05 to 26 wt%, 0.05 to 24 wt%, 0.05 to 22 wt%, 0.05 to 20 wt%, 0.1 to 30 wt%, 0.1 to 28 wt%, 0.1 to 26 wt%, 0.1 to 24 wt%, or 0.1 to 22 wt%, based on the total cosmetic composition, and for example, may contain 0.1 to 20 wt%, but is not limited thereto.

In one embodiment of the present invention, the cosmetic composition may contain the sodium base in an amount of 0.1 to 20 wt%, 0.1 to 15 wt%, 0.1 to 10 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 2 to 20 wt%, 2 to 15 wt%, 2 to 10 wt%, 3 to 20 wt%, 3 to 15 wt%, 3 to 10 wt%, 4 to 20 wt%, 4 to 15 wt%, or 4 to 10 wt%, for example, 4 to 8 wt% or 0.5 to 8 wt%, but is not limited thereto.

In the present invention, the cosmetic composition may additionally contain an amino acid.

In the present invention, the amino acid may include at least one selected from the group consisting of betaine, betaine salicylate, and arginine, but is not limited thereto.

The term "Betaine" in this specification refers to a substance rated Level 1 by the Environmental Working Group (EWG), also known as trimethylglycine (TMG), which has excellent skin penetration ability and can help soothe and moisturize the skin. For example, it may refer to an ingredient mainly used in hair conditioners or moisturizers. In addition, in the present invention, betaine may be betaine; or a physiologically or cosmetically acceptable salt thereof, such as, but not limited to, betaine salicylate.

The term "Arginine" in this specification is an amino acid used in the biosynthesis of proteins, and may be used interchangeably with "arginine" or "arginine".

In the present invention, the cosmetic composition may contain the amino acid in an amount of 0.1 to 20 wt%, 0.2 to 20 wt%, 0.3 to 20 wt%, or 0.4 to 20 wt% relative to the total cosmetic composition, for example, 0.5 to 20 wt%, but is not limited thereto.

In one embodiment of the present invention, the cosmetic composition may contain the amino acid in an amount of 0.05 to 20 wt%, 0.05 to 15 wt%, 0.05 to 10 wt%, 0.05 to 5 wt%, 0.1 to 20 wt%, 0.1 to 15 wt%, 0.1 to 10 wt%, 0.1 to 5 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 0.5 to 5 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 1 to 5 wt%, 2 to 20 wt%, 2 to 15 wt%, or 2 to 10 wt%, for example, 0.1 to 10 wt%, 0.1 to 5 % by weight, or 2 to 5 wt%, but is not limited thereto.

In the present invention, the cosmetic composition may additionally contain a polyol.

In the present invention, the polyol may include propylene glycol.

In one embodiment of the present invention, the cosmetic composition may contain the polyol in an amount of 0.05 to 20 wt%, 0.05 to 15 wt%, 0.05 to 10 wt%, 0.1 to 20 wt%, 0.1 to 15 wt%, 0.1 to 10 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 2 to 20 wt%, 2 to 15 wt%, 2 to 10 wt%, 5 to 20 wt%, 5 to 15 wt%, 5 to 10 wt%, 8 to 20 wt%, 8 to 15 wt%, or 8 to 10 wt%, based on the total cosmetic composition, for example, 8 to It may contain, but is not limited to, 12% by weight.

In the present invention, the cosmetic composition may additionally include at least one selected from the group consisting of a solvent, a thickener, and a preservative, but is not limited thereto.

In the present invention, the solvent may be a polyol, specifically a C1 to C6 polyol, and may include, for example, at least one selected from the group consisting of propylene glycol, ethoxy diglycol, glycerin, propanediol, and dipropylene glycol.

The term "thickening agent" in this specification may mean an ingredient used to maintain the viscosity and stability of a cosmetic composition, and in the present invention, the thickening agent may be at least one selected from the group consisting of glyceryl acrylate/acrylic acid copolymer, carbomer, and xanthan gum, and may be, for example, xanthan gum, but is not limited thereto.

The term "preservative" in this specification may mean an ingredient used to prevent deterioration of a cosmetic composition and maintain purity, and in the present invention, the preservative may be at least one selected from the group consisting of pentylene glycol, 1,2-hexanediol, ethylhexyl glycerin, caprylyl glycol, and phenoxyethanol, and may be, for example, 1,2-hexanediol, but is not limited thereto.

In the present invention, the cosmetic composition may additionally contain a moisturizer.

In the present invention, the moisturizer may be at least one selected from the group consisting of sodium hyaluronate, sodium PCA (sodium pyrrolidone carboxylate), sodium lactate, sodium gluconate, sodium chondroitin sulfate, sodium polyacrylate, hyaluronic acid, glycerin, and propanediol, but is not necessarily limited thereto.

In one embodiment of the present invention, the cosmetic composition may be one in which azelaic acid does not precipitate at low temperature (4°C).

In another embodiment of the present invention, the cosmetic composition may be one in which azelaic acid is dissolved at a low temperature (4°C).

The term "dissolution" used herein refers to the process by which a component disperses and mixes in a solvent to form a homogeneous solution. Dissolution ensures that the component is evenly distributed within the cosmetic, prevents precipitation under various temperature conditions, and becomes biologically available for skin absorption.

In addition, the usability of the manufactured cosmetic composition was evaluated, and as a result, it was specifically confirmed that the cosmetic composition of the comparative example was sticky and showed an unpleasant usability, whereas the cosmetic composition of the example showed a refreshing usability without being sticky.

In addition, the cosmetic composition manufactured above was evaluated for water activity, inflammatory lesion improvement effect, and anti-acne effect, and as a result, the cosmetic composition of the example not only showed an excellent inflammatory lesion improvement effect compared to the cosmetic composition of the comparative example, but also showed an excellent skin moisture improvement effect by increasing skin moisture by about 101.5%, and it was specifically confirmed that it exhibited a significant anti-acne effect.

In one embodiment of the present invention, the cosmetic composition may be used for moisturizing the skin, promoting moisturizing the skin, improving skin moisture, and/or improving skin inflammation.

Another aspect of the present invention is a composition for external application to the skin comprising azelaic acid and a sodium base.

The term "topical skin preparation" as used herein refers to a product that is applied directly to the skin to provide skin treatment, improvement, protection, soothing, relief, or cosmetic benefits, and encompasses cosmetics and dermatological cosmetics. Topical skin preparations can primarily exert local effects on the skin surface or specific areas, and the active ingredients contained in the preparation can penetrate through the skin barrier.

Since the composition for external application to the skin according to the present invention contains the same ingredients as the cosmetic composition according to another embodiment of the present invention described above, in order to avoid excessive complexity of the description herein, redundant contents are cited and the description thereof is omitted.

Another aspect of the present invention is a method for producing a transparent liquid type cosmetic composition or composition for external application to the skin containing a high content of azelaic acid, comprising the following steps:

A step of preparing a first mixture by mixing purified water and a thickening agent;

A step of preparing a second mixture by dissolving azelaic acid in a solvent under heating;

A step of preparing a third mixture by mixing purified water and sodium base; and

A step of preparing a composition by mixing the first mixture and the second mixture and then mixing the third mixture.

In the present invention, the cosmetic composition or the composition for external application to the skin may contain the azelaic acid in an amount of 0.1 to 30 wt%, 0.1 to 25 wt%, 0.1 to 20 wt%, 0.2 to 30 wt%, 0.2 to 25 wt%, 0.2 to 20 wt%, 0.3 to 30 wt%, 0.3 to 25 wt%, 0.3 to 20 wt%, 0.4 to 30 wt%, 0.4 to 25 wt%, 0.4 to 20 wt%, 0.5 to 30 wt% or 0.5 to 25 wt% relative to the total cosmetic composition or the composition for external application to the skin, and for example, may contain 0.5 to 20 wt%, but is not limited thereto.

In one embodiment of the present invention, the cosmetic composition or the composition for external application to the skin may contain the azelaic acid in an amount of 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 5 to 20 wt%, 5 to 15 wt%, 5 to 10 wt%, 10 to 20 wt%, 10 to 15 wt%, or 15 to 20 wt%, based on the total cosmetic composition or the composition for external application to the skin, and for example, may contain 10 to 15 wt%, but is not limited thereto.

In the present invention, the sodium base may include at least one selected from the group consisting of sodium hydroxide, sodium citrate, and sodium carbonate, but is not limited thereto.

In the present invention, the cosmetic composition or the composition for external application to the skin may contain the sodium salt in an amount of 0.05 to 30 wt%, 0.05 to 28 wt%, 0.05 to 26 wt%, 0.05 to 24 wt%, 0.05 to 22 wt%, 0.05 to 20 wt%, 0.1 to 30 wt%, 0.1 to 28 wt%, 0.1 to 26 wt%, 0.1 to 24 wt%, or 0.1 to 22 wt% relative to the total cosmetic composition or the composition for external application to the skin, and for example, may contain 0.1 to 20 wt%, but is not limited thereto.

In one embodiment of the present invention, the cosmetic composition or the composition for external application of the skin may contain the sodium salt in an amount of 0.1 to 20 wt%, 0.1 to 15 wt%, 0.1 to 10 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 2 to 20 wt%, 2 to 15 wt%, 2 to 10 wt%, 3 to 20 wt%, 3 to 15 wt%, 3 to 10 wt%, 4 to 20 wt%, 4 to 15 wt%, or 4 to 10 wt%, based on the total cosmetic composition or the composition for external application of the skin, and for example, may contain 4 to 8 wt% or 0.5 to 8 wt%, but is not limited thereto. It is not.

In the present invention, the first mixture may additionally include an amino acid.

In the present invention, the amino acid may include at least one selected from the group consisting of betaine, betaine salicylate, and arginine, but is not limited thereto.

In the present invention, the cosmetic composition or the composition for external application to the skin may contain the amino acid in an amount of 0.1 to 20 wt%, 0.2 to 20 wt%, 0.3 to 20 wt%, or 0.4 to 20 wt% relative to the total cosmetic composition or the composition for external application to the skin, and for example, may contain 0.5 to 20 wt%, but is not limited thereto.

In one embodiment of the present invention, the cosmetic composition or the composition for external application of the skin may contain the amino acid in an amount of 0.05 to 20 wt%, 0.05 to 15 wt%, 0.05 to 10 wt%, 0.05 to 5 wt%, 0.1 to 20 wt%, 0.1 to 15 wt%, 0.1 to 10 wt%, 0.1 to 5 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, 0.5 to 5 wt%, 1 to 20 wt%, 1 to 15 wt%, 1 to 10 wt%, 1 to 5 wt%, 2 to 20 wt%, 2 to 15 wt%, or 2 to 10 wt%, based on the total cosmetic composition or the composition for external application of the skin, for example, 2 to 5 May include, but is not limited to, weight %.

In the present invention, the solvent in the second mixture may be a polyol.

In the present invention, the polyol may include propylene glycol.

In the present invention, the step of preparing the second mixture may be heating and dissolving at a temperature of 55°C to 95°C, 55°C to 90°C, 55°C to 85°C, 60°C to 95°C, 60°C to 90°C, 60°C to 85°C, 65°C to 95°C, or 65°C to 90°C, and for example, heating and dissolving at a temperature of 65°C to 85°C, but is not limited thereto.

In one embodiment of the present invention, a first mixture was prepared by mixing purified water, an amino acid, a thickener, and a preservative, a second mixture was prepared by dissolving azelaic acid in a solvent by heating at 75°C, and then purified water and a sodium salt were mixed to prepare a third mixture. Thereafter, the first mixture and the second mixture were mixed, and then the third mixture was mixed to prepare a high-azelaic acid transparent liquid type cosmetic composition. Through experiments, it was specifically confirmed that the cosmetic composition can form a transparent liquid type formulation while containing a high content of azelaic acid, including a sodium salt and an amino acid that increase the solubility of azelaic acid, and has a refreshing feeling of use, an excellent skin moisture improvement effect, an excellent inflammatory lesion improvement effect, and a significant anti-acne effect, and is suitable for human use because it does not irritate the skin.

Although omitted in consideration of the complexity of the present specification, the description of the cosmetic composition in the aspect of the method for producing the cosmetic composition or the composition for external application to the skin can also be applied to the composition for external application to the skin, and therefore, the replacement of the cosmetic composition with the composition for external application to the skin is also included in the present invention.

The overlapping contents of the method for manufacturing the transparent liquid type high-content azelaic acid cosmetic composition and the transparent liquid type high-content azelaic acid cosmetic composition are omitted in consideration of the complexity of this specification.

The present invention relates to a transparent cosmetic composition containing azelaic acid and a sodium base, wherein the transparent cosmetic composition of the present invention not only contains azelaic acid in a high content, but also has the effect of being optimized for troubled skin, providing a refreshing feeling of use, and improving skin moisture.

Figure 1 shows the results of confirming the usability and solubility of cosmetic composition Example 1 manufactured according to one manufacturing example of the present invention.

Figure 2 shows the results of confirming the usability and solubility of comparative example 1 of a cosmetic composition manufactured according to one manufacturing example of the present invention.

Figure 3 shows the results of measuring the water activity of Example 1 of a cosmetic composition manufactured according to one experimental example of the present invention.

Figures 4 and 5 show graphs and photographs showing the evaluation results of improvement in inflammatory lesions of Example 1 of a cosmetic composition manufactured according to one experimental example of the present invention.

Figure 6 shows the results of confirming the low-temperature (4°C) stability of cosmetic compositions manufactured according to one manufacturing example of the present invention, Example 1, and Comparative Examples 6 to 8.

Figures 7 and 8 show the results of an anti-acne test of a cosmetic composition manufactured according to an experimental example of the present invention.

The present invention relates to a transparent liquid type cosmetic composition containing azelaic acid and a sodium base.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present invention. Unless otherwise defined, terms used herein should be interpreted as generally understood by those skilled in the art.

The drawings and examples of this specification are provided to enable those skilled in the art to easily understand and practice the present invention. Contents that may obscure the gist of the invention may be omitted from the drawings and examples, and the present invention is not limited to the drawings and examples.

Throughout this specification, whenever a part is said to "include" a component, this means that it may include other components, but not to the exclusion of other components, unless specifically stated otherwise.

Throughout this specification, "%" used to indicate the concentration of a particular substance is (wt/wt)% for solid/solid, (wt/vol)% for solid/liquid, and (vol/vol)% for liquid/liquid, unless otherwise stated.

Manufacturing example: Manufacturing of a cosmetic composition containing azelaic acid

Cosmetic compositions containing azelaic acid were prepared as shown in Tables 1 to 3 below (unit: weight %).

division Ingredient name (unit: weight%) Example 1 Example 2 Comparative Example 4 Comparative Example 5 First mixture purified water To 100 To 100 To 100 To 100 amino acids Betaine 2 0 0 0 Arginine 0 5 0 0 thickener xanthan gum 0.5 0.5 0.5 0.5 antiseptic 1,2-hexanediol 2 2 2 2 Second mixture menstruum Propylene glycol 10 10 10 10 azelaic acid 10 15 10 15 Third mixture
(sodium base solution) purified water 20 20 20 20 sodium base sodium hydroxide 4 0 4 0 Sodium citrate 0 8 0 8

division Ingredient name (unit: weight%) Comparative Example 1 Comparative Example 2 Comparative Example 3 First mixture purified water To 100 To 100 To 100 amino acids Betaine 2 2 2 Arginine 0 0 0 thickener xanthan gum 0.5 0.5 0.5 antiseptic 1,2-hexanediol 2 2 2 Second mixture menstruum Propylene glycol 10 10 10 azelaic acid 10 10 10 surfactant PEG-60 Hydrogenated Castor Oil 0 5 5 Third mixture
(basic solution) purified water 20 20 20 base potassium hydroxide 4 10 0 magnesium hydroxide 0 0 10

division Ingredient name (unit: weight%) Example 3 Example 4 Comparative Example 6 Comparative Example 7 Comparative Example 8 First mixture purified water To 100 To 100 To 100 To 100 To 100 amino acids Betaine 2 0 2 2 2 Arginine 0 5 0 0 0 thickener xanthan gum 0.5 0.5 0.5 0.5 0.5 antiseptic 1,2-hexanediol 2 2 2 2 2 Second mixture menstruum Propylene glycol 10 10 0 0 0 Butylene glycol 0 0 10 0 0 butanediol 0 0 0 10 0 azelaic acid 0.5 20 10 10 10 Third mixture
(sodium base solution) purified water 20 20 20 20 20 sodium base sodium hydroxide 0 8 4 4 4 Sodium citrate 0.5 0 0 0 0

Specifically, as shown in Table 1 above, purified water, amino acid (betaine or arginine), thickening agent xanthan gum, and preservative 1,2-hexanediol were sequentially added to a homomixer and mixed at 3,500 rpm for 10 minutes to prepare a first mixture. Thereafter, solvents propylene glycol and azelaic acid were separately dissolved by heating to 75°C, and a second mixture was prepared, which was then added to the homomixer and mixed at 3,500 rpm for 10 minutes. Then, purified water and sodium hydroxide or sodium citrate, which are sodium bases, were dissolved separately at room temperature to prepare a third mixture (sodium base solution), which was then placed in a homomixer and mixed at 3,500 rpm for 10 minutes to prepare cosmetic compositions of Examples 1 to 4, and cosmetic compositions of Comparative Examples 4 and 5 were prepared by excluding amino acids (betaine or arginine) in the above-mentioned manufacturing method.

As shown in Table 2 above, purified water, betaine as an amino acid, xanthan gum as a thickener, and 1,2-hexanediol as a preservative were sequentially added to a homomixer and mixed at 3,500 rpm for 10 minutes to prepare a first mixture. Thereafter, propylene glycol as a solvent, azelaic acid, and PEG-60 hydrogenated castor oil as a surfactant were separately dissolved by heating to 75°C to prepare a second mixture, which was then added to a homomixer and mixed at 3,500 rpm for 10 minutes. Then, purified water and potassium hydroxide or magnesium hydroxide, not sodium base, were separately dissolved at room temperature to prepare a third mixture (base solution), which was then placed in a homomixer and mixed at 3,500 rpm for 10 minutes to prepare cosmetic compositions of Comparative Examples 1 to 3.

In addition, as shown in Table 3 above, purified water, betaine, an amino acid, xanthan gum, a thickener, and 1,2-hexanediol, a preservative, were sequentially added to a homomixer and mixed at 3,500 rpm for 10 minutes to prepare a first mixture. Thereafter, instead of propylene glycol, butylene glycol (1,3-butanediol), butanediol (1,4-butanediol), or purified water was used as a solvent, and the solvent and azelaic acid were separately dissolved by heating to 75°C to prepare a second mixture, which was then added to a homomixer and mixed at 3,500 rpm for 10 minutes. Then, purified water and sodium hydroxide or sodium citrate, which are sodium bases, were dissolved separately at room temperature to prepare a third mixture (base solution), which was then placed in a homomixer and mixed at 3,500 rpm for 10 minutes to prepare cosmetic compositions of Comparative Examples 6 to 8.

Experimental Example: Evaluation of the feel and solubility of cosmetic compositions

The solubility, usability, water activity, and inflammatory lesion improvement effect of each cosmetic composition manufactured according to the above manufacturing example were evaluated as follows.

Solubility evaluation

To evaluate solubility, each cosmetic composition of Examples 1 to 4 and Comparative Examples 1 to 8 was stored at temperature conditions of 4°C, 25°C, and 45°C for one week to check whether a precipitated substance was present, which is shown in FIG. 1, FIG. 2, and Table 4 below.

4℃ 25℃ 45℃ Example 1 × × × Example 2 × × × Example 3 × × × Example 4 × × × Comparative Example 1 ○ ○ × Comparative Example 2 ○ × × Comparative Example 3 ○ × × Comparative Example 4 △ × × Comparative Example 5 △ × × Comparative Example 6 ○ × × Comparative Example 7 ○ × × Comparative Example 8 ○ × ×

(Solubility evaluation criteria: Not precipitated - ×, Precipitated at low temperature but re-dissolved at room temperature - △, Precipitated - ○)

As a result of the verification, as shown in FIG. 1, FIG. 2 and Table 4 above, it was confirmed that the cosmetic compositions of Examples 1 to 4 including a sodium base and an amino acid did not have substances precipitated not only at a temperature higher than room temperature (25°C) but also at a low temperature (4°C), and the cosmetic compositions of Comparative Examples 1 to 3 and Comparative Examples 6 to 8 did not have substances precipitated at a temperature higher than high temperature (45°C), but substances precipitated were present at temperature conditions of room temperature (25°C) and low temperature (4°C), and the cosmetic compositions of Comparative Examples 4 and 5 were redissolved at room temperature and were superior to the other comparative examples and could be used as cosmetic compositions.

In addition, when comparing the cosmetic compositions of Example 1 and Comparative Examples 1 to 3 containing the same amount of azelaic acid, there was a difference in whether precipitation occurred under temperature conditions of low temperature (4°C) and room temperature (25°C) depending on whether the base included in the cosmetic composition was a sodium base, confirming that the sodium base had the effect of increasing the solubility of azelaic acid. At this time, even though a surfactant was used to dissolve azelaic acid in Comparative Examples 2 and 3, the solubility was significantly superior in Example 1. Since the cosmetic compositions of Comparative Examples and Examples had a pH adjusted to 5 to 7, it is judged that the difference in whether precipitation occurred between them is not due to a difference in solubility depending on the pH, but rather that whether precipitation occurred was determined depending on the type of base.

Moreover, when comparing the cosmetic compositions of Example 1 and Comparative Examples 6 to 8, which differ only in the type of solvent but have the same other components and contents, there was a difference in whether precipitation occurred at a low temperature (4°C) depending on the type of solvent, and thus it was confirmed that the use of propylene glycol had the effect of increasing the solubility of azelaic acid compared to the case where only butylene glycol or butanediol was used as a solvent (see Table 4). In addition, as shown in Fig. 6, it was confirmed that no precipitation occurred in Example 1 at a low temperature (4°C), while the precipitated substances settled to the bottom in Comparative Examples 6 to 8. In addition, these results were the same regardless of whether amino acids were included (for example, even if betaine or arginine was not included).

From the above results, the inventors of the present invention confirmed that propylene glycol as a solvent has the effect of increasing the solubility of azelaic acid. However, this does not mean that propylene glycol must be included as a solvent, and that other polyols must not be included as solvents other than propylene glycol. Accordingly, the cosmetic composition of the present invention includes propylene glycol as a solvent, which is a polyol, and may further include butylene glycol, butanediol, 1,2-hexanediol, and/or pentylene glycol.

Therefore, it was confirmed that the cosmetic composition of the present invention can provide a transparent liquid type cosmetic composition containing a high content of azelaic acid without causing precipitation, since it includes an amino acid, sodium base, and/or polyol that increases the solubility of azelaic acid.

Usability evaluation

To evaluate the usability, the cosmetic compositions of Example 1, Comparative Example 2, and Comparative Example 3 were applied to the face of 10 professional panelists aged 24 to 45, and then a stickiness evaluation was performed.

Specifically, each cosmetic composition was applied to the face and the stickiness was evaluated, and the results are shown in Table 5 below.

score Example 1 Comparative Example 2 Comparative Example 3 Panel 1 0 2 2 Panel 2 1 2 2 Panel 3 1 3 3 Panel 4 0 2 3 Panel 5 1 2 3 Panel 6 0 2 3 Panel 7 1 3 3 Panel 8 0 2 3 Panel 9 0 2 3 Panel 10 1 2 2 average 0.5 2.2 2.7

(Usability evaluation criteria: no stickiness on the skin - 0 points, slightly sticky - 1 point, moderate stickiness - 2 points, severe stickiness - 3 points)

As a result of the evaluation, as shown in Table 5 above, in the case of the cosmetic composition of Example 1, the average stickiness score of 10 panelists was evaluated as 0.5 points after application to the face, indicating a refreshing feeling without stickiness even when applied to the skin.

On the other hand, in the case of the cosmetic compositions of Comparative Examples 2 and 3, the average stickiness scores of 10 panelists were evaluated as 2.2 and 2.7 points, respectively, after application to the face, indicating that the stickiness was severe and gave an unpleasant feeling when used.

In addition, as shown in FIGS. 1 and 2, in order to evaluate stickiness, a stickiness test was conducted by applying the cosmetic composition of Example 1 or Comparative Example 1 on the back of the hand, placing a sprinkle on it, and visually observing the extent to which the sprinkle was stuck. As a result, compared to the case where the cosmetic composition of Comparative Example 1 was applied, the extent to which the sprinkle was stuck was significantly less when the cosmetic composition of Example 1 was applied, confirming that the usability of Example 1 was excellent without stickiness.

Accordingly, it was confirmed that the cosmetic composition of the present invention can provide a transparent liquid type cosmetic composition that contains a high content of azelaic acid while providing a refreshing feeling of use, since it includes an amino acid, sodium base, and/or polyol that increases the solubility of azelaic acid.

Water activity evaluation

To evaluate water activity, one 33-year-old professional panelist washed the test area (inner side of the lower arm) with soap and waited for 10 minutes in a constant temperature and humidity room (22 ± 2℃, 40 to 60% RH). Then, the cosmetic composition of Example 1 was applied, and 10 minutes later, the skin moisture content (A.U., Arbituary Unit) was measured using a measuring device (Epsilon, BiOX) to confirm the water activity, which is shown in Fig. 3.

As a result of the measurement, as shown in Fig. 3, it was confirmed that the skin moisture content (A.U.) increased by approximately 101.5% from 2.86 to 5.76 according to the application of the cosmetic composition of Example 1.

Therefore, it was confirmed that the cosmetic composition of the present invention can provide a transparent liquid type cosmetic composition that contains a high content of azelaic acid while exhibiting an excellent skin moisture improvement effect, since it includes an amino acid, sodium base, and/or polyol that increases the solubility of azelaic acid.

Evaluation of improvement in inflammatory lesions

To evaluate the improvement of inflammatory lesions, the cosmetic composition of Example 1 was used on five expert panelists aged 24 to 35 years to evaluate whether inflammatory lesions improved for 4 weeks, and the results are shown in Figs. 4 and 5.

The evaluation items are as follows:

Pimple: A firm lump on the skin measuring approximately 0.5 cm to 1.0 cm in diameter, which is an intermediate form between inflammatory and non-inflammatory acne lesions.

Pustule: An inflammatory acne lesion that is a raised, pus-filled pocket.

As a result of the evaluation, as shown in FIGS. 4 and 5, it was confirmed that after 4 weeks of using the cosmetic composition of Example 1, the number of papules was reduced by about 47.8% and the number of pustules was reduced by about 71.4%.

Therefore, it was confirmed that the cosmetic composition of the present invention includes an amino acid, sodium base, and/or polyol that increases the solubility of azelaic acid, and thus can provide a transparent liquid type cosmetic composition that can be used for improving acne by showing an excellent inflammatory lesion improvement effect while containing a high amount of azelaic acid.

Anti-acne test results

In order to confirm the anti-acne test effect of the cosmetic composition of Example 1, the colonies were counted after the Minimum Inhibitory Concentration (MIC) assay. In the case of the MIC assessment, 180 μL of a culture solution of Cutibacterium acnes (C. acnes ), the acne-causing bacteria, was dispensed into 20 μL of the sample, and the experiment was conducted by diluting the final concentration to 1.0 wt% when the sample with an active substance (i.e., azelaic acid) content of 10 wt% was treated. In the negative control group, no treatment was performed with the sample, and in the positive control group, 250 μg/mL of the antibiotic tetracycline hydrochloride was used as the sample, and in the experimental group, the cosmetic composition of Example 1 was used as the sample.

As a result, as shown in Fig. 7, when the contents of azelaic acid, an active ingredient included in the cosmetic composition of Example 1, were 0.015 wt%, 0.15 wt%, and 1.5 wt%, the growth inhibition activity (%) was approximately 100%, which was similar to or higher than the growth inhibition activity of 98.8% of the antibiotic treatment group, which was the positive control group, confirming that 100% of acne bacteria were killed.

In addition, as shown in Fig. 8, compared to the negative control group (untreated acne) that was not treated with any acne-causing bacteria ( C. acnes ), no microbial colonies were observed in the positive control group (antibiotic) treated with tetracycline hydrochloride, the 100-fold dilution of Example 1, the 10-fold dilution of Example 1, and the experimental group treated with the original solution of Example 1, confirming that the growth of the acne-causing bacteria was significantly inhibited.

Therefore, from the above results, it was confirmed that the cosmetic composition of Example 1 according to the present invention exhibited a significant anti-acne effect.

Results of primary irritation evaluation on human skin

A primary irritation evaluation was conducted on a panel of 31 female volunteers aged 19 to 59 years for the cosmetic composition of Example 1. The test substance was applied to the back of the subjects using an IQ UltraTM chamber for 24 hours, and the degree of skin irritation was evaluated according to the judgment criteria of the PCPC Guideline (Personal Care Products Council, USA) 30 minutes and 24 hours after removal of the patch.

As a result, the cosmetic composition of Example 1, a test substance, did not show any skin irritation reaction 30 minutes and 24 hours after removal of the patch, and the average irritation index was 0.00. Therefore, the cosmetic composition of Example 1 was judged to be suitable for use on human skin, as it is a substance with an irritation category corresponding to an average irritation index of 0.00.

Sintering

In summary of the results of the above examples, the cosmetic composition having a high azelaic acid content of the present invention includes a sodium base, an amino acid, and/or a polyol that increases the solubility of azelaic acid, thereby providing a transparent liquid type cosmetic composition having excellent formulation stability that does not cause precipitation under various temperature conditions despite containing a high content of azelaic acid, and has a refreshing feeling of use without stickiness, an excellent skin moisture improvement effect, an excellent inflammatory lesion improvement effect, and a significant anti-acne effect, and has been specifically confirmed to be suitable for human use because it does not irritate the skin, suggesting that it can be usefully used as a cosmetic composition.

While the present invention has been described in detail above, it should be apparent to those skilled in the art that these specific descriptions are merely preferred embodiments and are not intended to limit the scope of the present invention. Therefore, the substantial scope of the present invention is defined by the appended claims and their equivalents.

The present invention relates to a transparent liquid type cosmetic composition containing azelaic acid and a sodium salt, wherein the transparent liquid type cosmetic composition of the present invention not only contains azelaic acid in a high content, but also provides a refreshing feeling optimized for troubled skin and has a skin moisture improvement effect, including a sodium salt, an amino acid, and a polyol that increase the solubility of azelaic acid.

Claims (15)

A cosmetic composition comprising azelaic acid and a sodium base. A cosmetic composition according to claim 1, wherein the cosmetic composition comprises 0.5 to 20 wt% of the azelaic acid relative to the total cosmetic composition. A cosmetic composition in claim 1, wherein the sodium base comprises at least one selected from the group consisting of sodium hydroxide, sodium citrate, and sodium carbonate. A cosmetic composition according to claim 1, wherein the cosmetic composition contains 0.1 to 20 wt% of the sodium salt relative to the total cosmetic composition. A cosmetic composition according to claim 1, wherein the cosmetic composition further comprises an amino acid. A cosmetic composition in claim 5, wherein the amino acid comprises at least one selected from the group consisting of betaine, betaine salicylate, and arginine. A cosmetic composition according to claim 5, wherein the cosmetic composition contains 0.05 to 20 wt% of the amino acid relative to the total cosmetic composition. A cosmetic composition according to claim 1, wherein the cosmetic composition further comprises a polyol. A cosmetic composition according to claim 8, wherein the polyol comprises propylene glycol. A cosmetic composition according to claim 1, wherein the cosmetic composition further comprises at least one selected from the group consisting of a solvent, a thickener, and a preservative. A composition for external application to the skin comprising azelaic acid and a sodium base. A method for producing a transparent liquid type cosmetic composition or composition for external application to the skin containing a high content of azelaic acid, comprising the following steps: A step of preparing a first mixture by mixing purified water and a thickening agent; A step of preparing a second mixture by dissolving azelaic acid in a solvent under heating; A step of preparing a third mixture by mixing purified water and sodium base; and A step of preparing a composition by mixing the first mixture and the second mixture and then mixing the third mixture. A manufacturing method according to claim 12, wherein the cosmetic composition or the composition for external application to the skin contains 0.5 to 20 wt% of the azelaic acid relative to the total cosmetic composition or the composition for external application to the skin. A manufacturing method according to claim 12, wherein the first mixture further comprises an amino acid. A manufacturing method in claim 12, wherein the solvent in the second mixture is a polyol.