Cosmetic composition with improved skin water absorption

Abstract

The present invention relates to a cosmetic composition with improved skin water absorption. The cosmetic composition according to the present invention contains niacinamide and citric acid together, so that when the cosmetic composition is applied to the skin, niacinamide does not remain even if the solvent and preparation evaporate or are absorbed. This can solve usability problems such as a foreign body sensation caused by remaining niacinamide and white stains.

Description

[Technical field]

[0001] The present invention relates to a cosmetic composition having improved water absorbency against the skin. [Background technology]

[0002] Niacinamide (or nicotinamide), a type of niacin in the B vitamin family, is a precursor of the intracellular antioxidant NADPH and is converted into NADPH in the body, playing a vital role in the antioxidant function of cells, the process of generating bioenergy, and the various physiological functions of many enzymes.

[0003] Various studies on niacinamide have been conducted, and many reports have been published on its various effects. In particular, niacinamide's whitening effect (EP0396422A1), moisturizing effect by improving the skin barrier (BR.J.Dermatol.2000.143(3), 524-31), anti-inflammatory and inflammatory acne improving effect (Int J Dermato.1995, 34:434-437), and anti-aging effect by improving wrinkles and elasticity (Dermatol Surg.2005, 31:860-865) have been reported.

[0004] As the cosmetics industry develops, the development of highly functional cosmetics is being continuously carried out across the entire cosmetics industry. Recently, as more and more consumers are demanding specific effects such as "skin whitening, wrinkle reduction, elasticity, and pore refinement," the value of functional cosmetics with enhanced efficacy ingredients is increasing in the cosmetics industry.

[0005] In particular, niacinamide, a water-soluble vitamin B3, is widely used in cosmetics due to its various effects on the skin as mentioned above. Recently, many cosmetics containing high amounts of niacinamide (5% or more) have been released to enhance the efficacy of this ingredient.

[0006] However, when niacinamide is simply mixed in a high content of a cosmetic formulation and applied, the sensory effect is not so great compared to the content. This is because when the cosmetic formulation is applied to the skin, the percutaneous absorption rate of niacinamide, which is a water-soluble substance, is significantly slower than the evaporation or absorption rate of the solvent, so it remains on the skin without being absorbed. Therefore, even if a high content of niacinamide is applied, it does not penetrate the skin and remains white on the skin, so the efficacy is not fully demonstrated compared to the amount of niacinamide applied, and white marks remain on the skin, reducing the aesthetics and causing a foreign body sensation, which is a disadvantage.

[0007] Under the above background, the present inventors have confirmed that by using niacinamide and citric acid together, when a cosmetic composition containing a high content of niacinamide is applied to the skin and the formulation evaporates, the niacinamide does not remain as a white residue, and the skin permeability is improved. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] EP0396422A1 [Non-patent literature]

[0009] [Non-Patent Document 1] BR.J.Dermatol.2000.143(3), 524-31 [Non-Patent Document 2] Int J Dermato.1995, 34:434-437 [Non-Patent Document 3] Dermatol Surg.2005, 31:860-865 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to provide a cosmetic composition which, when applied to the skin, does not leave a white residue of high-content niacinamide even after the preparation evaporates, and has improved skin permeability. [Means for solving the problem]

[0011] The present invention comprises niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The cosmetic composition has a molar ratio of niacinamide to citric acid of 8:1 to 1:4.5.

[0012] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The present invention provides a method for increasing dermal absorption and / or dermal permeation of niacinamide, using a cosmetic composition in which the molar ratio of niacinamide to citric acid is 8:1 to 1:4.5.

[0013] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The present invention provides a method for reducing the amount of niacinamide remaining on skin, using a cosmetic composition in which the molar ratio of niacinamide to citric acid is 8:1 to 1:4.5.

[0014] The present invention comprises niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The molar ratio of niacinamide to citric acid is 8:1 to 1:4.5. The cosmetic composition is used in the manufacture of cosmetics for increasing the skin absorption and / or skin permeation of niacinamide.

[0015] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The molar ratio of niacinamide to citric acid is 8:1 to 1:4.5. The present invention provides a cosmetic composition for use in the manufacture of cosmetics for reducing the skin residue of niacinamide. Effect of the Invention

[0016] The cosmetic composition according to the present invention contains niacinamide and citric acid together, so that when the cosmetic composition is applied to the skin, niacinamide does not remain as white even after the solvent and preparation evaporate and / or are absorbed, thereby solving usability problems caused by the foreign body sensation and white stains caused by the residue of niacinamide. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention relates to a cosmetic composition comprising niacinamide; and citric acid.

[0018] The configuration of the present invention will be specifically described below.

[0019] When a part is described as "comprising" a certain element, this does not mean to exclude other elements, but means that the part may further include other elements, unless specifically stated to the contrary.

[0020] In the present invention, niacinamide is a type of niacin, which is a vitamin B group, and can be contained in the cosmetic composition for the purpose of improving skin, such as whitening, moisturizing, anti-inflammatory and inflammatory acne treatment, and wrinkle and elasticity improvement.

[0021] The niacinamide exists as a solid at room temperature, and a cosmetic composition containing a high content of niacinamide has a problem that, when applied to the skin, the solvent and preparation evaporate or are absorbed, and the niacinamide remains as a white residue. When niacinamide is used together with citric acid, which will be described later, in the present invention, the interaction between the niacinamide and citric acid can improve skin absorption. Through this, when the cosmetic composition is applied to the skin, even if the solvent and preparation evaporate or are absorbed, niacinamide does not remain on the skin, and many problems caused by the residue of niacinamide can be solved.

[0022] That is, it may allow for more effective dermal absorption and penetration of niacinamide.

[0023] In addition, the skin permeation amount of niacinamide in the cosmetic composition of the present invention may be 1.5 times or more as compared to a composition not containing citric acid. The skin permeation amount can be measured by the method of Example-Experimental Example 3, and is the skin permeation amount when applied for the same time, and the application time may be 18 hours.

[0024] In one embodiment, the content of niacinamide may be 5% by weight or more, 6% by weight or more, 7% by weight or more, 8% by weight or more, 9% by weight or more, 10% by weight or more, 15% by weight or more, or 20% by weight or more, and the upper limit may be 50% by weight or less, based on the total weight (100% by weight) of the cosmetic composition. Specifically, the content of niacinamide may be 5-50% by weight, 5-20% by weight, 5-15% by weight, 6-50% by weight, 6-20% by weight, 6-15% by weight, 7-50% by weight, 7-20% by weight, 7-15% by weight, 8-50% by weight, 8-20% by weight, 8-15% by weight, 9-50% by weight, 9-20% by weight, 9-15% by weight, 10-50% by weight, 10-20% by weight, 10-15% by weight, 15-50% by weight, 15-20% by weight, or 20-50% by weight. If the content of niacinamide is less than 5% by weight, the desired effect of niacinamide cannot be obtained, and if it exceeds 50% by weight, it may cause irritation to the skin.

[0025] In the present invention, citric acid may be used together with niacinamide to enhance the skin absorption and permeation of the niacinamide.

[0026] In one embodiment, the citric acid may be hydrous citric acid, if necessary.

[0027] In one specific example, the content of citric acid may be 0.9% by weight or more, 1% by weight or more, 1.5% by weight or more, 2.5% by weight or more, 3.6% by weight or more, 7.5% by weight or more, 10% by weight or more, 15% by weight or more, 20% by weight or more, 25% by weight or more, or 30% by weight or more, based on the total weight (100% by weight) of the cosmetic composition. The upper limit of the content may be 50% by weight or less or 40% by weight or less. Specifically, the content of citric acid may be 0.9 to 2.5% by weight, 2.6 to 3.5% by weight, 3.6 to 7.5% by weight, 7.5 to 15% by weight, 16 to 20% by weight, 21 to 30% by weight, 31 to 35% by weight, 10 to 20% by weight, 25 to 35% by weight, 1 to 40% by weight, 1.5 to 35% by weight, 2 to 30% by weight, or 10 to 25% by weight. If the content is less than 0.9% by weight, there is no effect of improving the skin absorption and skin permeation of niacinamide, and if the content exceeds 50% by weight, there is a risk of irritation to the skin. When hydrous citric acid is used as the citric acid, the content can be appropriately adjusted based on citric acid.

[0028] In one specific example, the citric acid content may be 0.9 to 35% by weight based on 5% by weight of niacinamide, the citric acid content may be 1.5 to 50% by weight based on 10% by weight of niacinamide, and the citric acid content may be 3 to 50% by weight based on 20% by weight of niacinamide.

[0029] In one specific example, the molar ratio of niacinamide and citric acid may be 8:1 to 1:4.5, 6:1 to 4:1, 4:1 to 1:4, 2:1 to 1:4, 1:1 to 1:4, 4:1 to 1:2, or 4:1 to 1:1. The weight ratio of niacinamide and citric acid may be 1:0.2 to 1:7.5 or 1:0.3 to 1:7, specifically, 1:0.3 to 1:0.4, 1:0.5 to 1:0.7, 1:0.75 to 1:2.5, 1:2.6 to 1:3.0, 1:3.1 to 1:4.5, 1:4.6 to 1:5.5, or 1:5.6 to 1:7. If it is out of the above range, problems such as niacinamide remaining white on the skin may occur.

[0030] In one embodiment, the cosmetic composition may further include panthenol in addition to citric acid. The present invention uses citric acid to solve the problem of residual niacinamide, but if the citric acid is used in an excessive amount, the composition may have a low pH, which may cause skin irritation, and the formulation may become unstable. Therefore, the present invention further includes panthenol to alleviate irritation caused by a decrease in pH due to the excessive use of citric acid, and to further improve the skin absorption and skin permeation of niacinamide.

[0031] The content of the panthenol may be 0.05 wt% or more, 0.66 wt% or more, 2.0 wt% or more, 3.4 wt% or more, 5 wt% or more, 6.2 wt% or more, 9.0 wt% or more, 11 wt% or more, 14.6 wt% or more, 23 wt% or more, or 31 wt% or more, based on the total weight (100 wt%) of the cosmetic composition. The upper limit of the content of the panthenol may be 65 wt% or less, 48 ​​wt% or less, or 31 wt% or less.

[0032] In one embodiment, the content of panthenol can be appropriately adjusted according to the content of niacinamide and citric acid, and the panthenol can partially replace the content of citric acid. For example, the molar ratio of niacinamide, citric acid, and panthenol may be 8:1 to 1:4.5, 6:1 to 4:1, 4:1 to 1:4, 2:1 to 1:4, 1:1 to 1:4, 4:1 to 1:2, or 4:1 to 1:1.

[0033] In one embodiment, the cosmetic composition may further include one or more selected from the group consisting of erythritol, xylitol, and xylityl glucoside. The erythritol, xylitol, and / or xylityl glucoside may mitigate irritation caused by a decrease in pH due to excessive use of citric acid together with panthenol.

[0034] The content of the erythritol may be 0.03 wt% or more, 0.06 wt% or more, 0.1 wt% or more, or 0.2 wt% or more based on the total weight (100 wt%) of the cosmetic composition, and the upper limit of the content may be 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, or 0.5 wt% or less.

[0035] The content of xylitol may be 0.03 wt% or more, 0.07 wt% or more, 0.1 wt% or more, or 0.3 wt% or more based on the total weight (100 wt%) of the cosmetic composition. The upper limit of the content may be 5 wt% or less, 3.8 wt% or less, 2.5 wt% or less, 1.3 wt% or less, or 0.7 wt% or less.

[0036] The content of the xylitylglucoside may be 0.08% by weight or more, 0.1% by weight or more, 0.3% by weight or more, or 0.6% by weight or more based on the total weight (100% by weight) of the cosmetic composition, and the upper limit of the content may be 10.3% by weight or less, 7.8% by weight or less, 5.2% by weight or less, 2.6% by weight or less, or 1.3% by weight or less.

[0037] In one embodiment, the cosmetic composition according to the present invention may have an acidity adjusted to a value of pH 3.5 to pH 10 in order to improve discomfort such as skin irritation when applied to the skin.

[0038] The cosmetic composition according to the present invention may contain an emulsion component in addition to the above-mentioned components. The emulsion component may be included in the composition to help niacinamide to be present stably in the composition.

[0039] In one embodiment, the milky component may be one or more of oil and wax. The oil and wax may be any oil or wax commonly used in the art as a cosmetic ingredient. For example, the oil may be a silicone-based oil, an ester-based oil, a triglyceride-based oil, a hydrocarbon-based oil, or a vegetable oil, and one or more of these ingredients may be used in combination as needed.

[0040] The silicone oil can be silicone fluid oil or silicone crosspolymer dispersed in oil.For example, the silicone fluid oil can be cyclopentasiloxane, cyclohexasiloxane, cycloheptasiloxane, cyclomethicone, cyclophenylmethicone, cyclotetrasiloxane, cyclotrisiloxane, dimethicone, capryl dimethicone, caprylyl trimethicone, caprylyl methicone, cetearyl methicone, hexadecyl methicone, hexyl methicone, lauryl methicone, myristyl methicone, phenyl methicone, stearyl methicone, stearyl dimethicone, trifluoropropyl methicone, cetyl dimethicone, diphenylsiloxyphenyl trimethicone, dimethyl polysiloxane, methyl phenyl polysiloxane, decamethyl cyclopentasiloxane, methyl trimethicone or phenyl trimethicone. The silicone oil component can be used alone or in combination of two or more kinds of oils. The silicone crosspolymer can be, but is not limited to, dimethicone crosspolymer, dimethicone / vinyl dimethicone crosspolymer, dimethicone PEG-10 / 15 crosspolymer, or PEG-12 dimethicone / PPG-20 crosspolymer.

[0041] Ester oils include ascorbyl palmitate, ascorbyl linoleate, ascorbyl stearate, diisostearyl malate, benzyl benzoate, benzyl laurate, butylene glycol dicaprylate / dicaprate, butylene glycol diisononanoate, butylene glycol laurate, butylene glycol stearate, butyl isostearate, cetearyl isononanoate, cetearyl nonanoate, cetearyl caprylate, cetyl ethylhexanoate, cetyl isononanoate, ethylhexyl caprylate / caprate, ethylhexyl isononanoate, ethylhexyl isostearate, ethylhexyl laurate, hexyl laurate, octyldodecyl isostearate, isopropyl isostearate, isostearyl isononanoate, isostearyl isostearate, isocetyl ethylhexanoate, ne Examples of usable compounds include dipentyl glycol dicaprate, neopentyl glycol diethylhexanoate, neopentyl glycol diisononanoate, neopentyl glycol diisostearate, pentaerythrityl stearate, pentaerythrityl tetraethylhexanoate, dipentaerythrityl hexaacid ester, polyglyceryl-2-diisostearate, polyglyceryl-2-sesquiisostearate, polyglyceryl-2-isostearate, polyglyceryl-2-tetraisostearate, polyglyceryl-2-triisostearate, polyglyceryl-3-diisostearate, polyglyceryl-3-isostearate, polyglyceryl-4-diisostearate, polyglyceryl-4-isostearate, polyglyceryl-6-diisostearate, polyglyceryl-6-sesquiisostearate, and triethylhexanoin.

[0042] Examples of triglyceride oils that can be used include C8-C12 acid triglyceride, C12-C18 acid triglyceride, caprylic / capric / triglyceride, caprylic / capric / lauric triglyceride, C10-C40 isoalkyl acid triglyceride, C10-C18 triglyceride, glyceryl triacetylhydrostearate, soybean glyceride, tribehenin, tricaprin, triethylhexanoin, triheptanoin, triisostearin, tripalmitin, and tristearin.

[0043] Examples of the hydrocarbon oil that can be used include liquid paraffin (mineral oil), paraffin, Vaseline, microcrystalline wax, and squalane.

[0044] As vegetable oils, avocado oil, wheat germ oil, rosehip oil, shea butter, almond oil, olive oil, macadamia oil, argan oil, meadowfoam oil, sunflower oil, castor oil, camellia oil, corn oil, safflower oil, soybean oil, rapeseed oil, macadamia nut oil, jojoba oil, palm oil, palm kernel oil, or coconut oil can be used.

[0045] The wax may be any wax commonly used in cosmetics, such as a hydrocarbon wax, a vegetable wax, or a silicone wax, etc. For example, it may include, but is not limited to, candelilla wax, carnauba wax, rice wax, beeswax, lanolin, ozokerite, ceresin wax, paraffin wax, microcrystalline wax, C30-C45 alkyldimethylsilyl polypropylsilsesquioxane, ethylene / propylene copolymer, or polyethylene wax.

[0046] The content of the milky component is not particularly limited, and the milky component may be contained in an appropriate amount in the cosmetic composition.

[0047] The cosmetic composition of the present invention may further contain all kinds of ingredients that can be used in ordinary cosmetics, for example, moisturizing agents such as glycerin, butylene glycol, propylene glycol, hexanediol, methyl gluceth-20, diglycerin, and ethylhexylglycerin; UV blocking agents such as ethylhexyl methoxycinnamate, ethylhexyl salicylate, ethylhexyl triazone, octocrylene, and bis-ethylhexyloxyphenol methoxyphenyl triazine; pH adjusting agents such as triethanolamine; carbomer, xanthan gum, acrylates / C10-30 alkyl acrylate crosspolymer, and hyaluronic acid; preservatives such as phenoxyethanol, methylparaben, and propylparaben; antioxidants such as BHT, ethyl ascorbyl ether, and ascorbic acid; skin conditioning agents such as β-glucan; surfactants such as cetearyl glucoside and sorbitan stearate; and fragrances or colorants, and there are no limitations on the ingredients.

[0048] Each of the components contained in the cosmetic composition according to the present invention may be preferably contained in the cosmetic composition according to the present invention within a range not exceeding the maximum usage amount stipulated in the "Cosmetic Safety Technical Standards" established by the Chinese government.

[0049] The cosmetic composition according to the present invention may be prepared in any form commonly used in the art. For example, the cosmetic composition may have the form of a toner such as a softening toner or a nutritious toner, a spray-type toner, a milky lotion such as a facial lotion or a body lotion, a cream such as a nutritious cream, a moisturizing cream, or an eye cream, a stick, an essence, a cosmetic ointment, a spray, a gel, a pack, a sunscreen, a makeup base, a liquid or spray-type foundation, a powder, a makeup remover such as a cleansing lotion or a cleansing oil, or a cleanser such as a cleansing foam, a soap, or a body wash, but is not limited thereto.

[0050] In one embodiment, the formulation of the cosmetic composition may be a water-based formulation, a water-in-oil type (W / O), an oil-in-water type (O / W), a solubilized formulation, or an oil formulation.

[0051] The cosmetic composition of the present invention can be used in a conventional manner, and the frequency of use may vary depending on the skin condition or preference of the user.

[0052] The cosmetic composition according to the present invention has the effect of significantly improving the amount of niacinamide remaining on the skin due to solvent evaporation upon application.

[0053] In one specific example, the change in L value measured with a chromameter before and after application of the cosmetic composition may be 5 or less. When the change in L value is 5 or less, it can be determined that there is almost no hue difference due to residual niacinamide. Such a change in L value can be measured and calculated according to the method in the <Reference> section of the Examples.

[0054] The present invention also relates to a method for producing the above-mentioned cosmetic composition.

[0055] The cosmetic composition according to the present invention may be prepared by preparing a mixture of niacinamide and citric acid and then mixing it with other ingredients used in general cosmetic compositions, or by mixing niacinamide, citric acid, and other ingredients together.

[0056] In one embodiment, a mixture of niacinamide and citric acid can be made by mixing niacinamide, citric acid, and purified water.

[0057] The mixing may be performed at 45 to 90° C., 45 to 80° C., or 60 to 80° C. As a result, niacinamide and citric acid are uniformly mixed in purified water, and a skin improving effect, low irritation to the skin, and excellent formulation stability can be realized.

[0058] In one embodiment, panthenol can be added to the mixture of niacinamide and citric acid.

[0059] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The present invention provides a method for increasing dermal absorption and / or dermal permeation of niacinamide, using a cosmetic composition in which the molar ratio of niacinamide to citric acid is 8:1 to 1:4.5.

[0060] The cosmetic composition according to the present invention may further contain panthenol, and the molar ratio of the niacinamide to the sum of citric acid and panthenol may be 8:1 to 1:4.5.

[0061] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The present invention provides a method for reducing the amount of niacinamide remaining on skin, using a cosmetic composition in which the molar ratio of niacinamide to citric acid is 8:1 to 1:4.5.

[0062] The cosmetic composition according to the present invention may further contain panthenol, and the molar ratio of the niacinamide to the sum of citric acid and panthenol may be 8:1 to 1:4.5.

[0063] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The molar ratio of niacinamide to citric acid is 8:1 to 1:4.5. The cosmetic composition is used in the manufacture of cosmetics for increasing the skin absorption and / or skin permeation of niacinamide.

[0064] The cosmetic composition according to the present invention may further contain panthenol, and the molar ratio of the niacinamide to the sum of citric acid and panthenol may be 8:1 to 1:4.5.

[0065] The present invention also provides a composition comprising: niacinamide; and citric acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, The molar ratio of niacinamide to citric acid is 8:1 to 1:4.5. The present invention provides a cosmetic composition for use in the manufacture of cosmetics for reducing the skin residue of niacinamide.

[0066] The cosmetic composition according to the present invention may further contain panthenol, and the molar ratio of the niacinamide to the sum of citric acid and panthenol may be 8:1 to 1:4.5.

[0067] The present invention will be described in detail with reference to the following examples. The following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples. The following examples are provided to complete the disclosure of the present invention and to fully inform those skilled in the art of the present invention of the scope of the invention, and the present invention is defined only by the scope of the claims. EXAMPLES

[0068] <Reference> Evaluation method 1: Residual evaluation of niacinamide by naked eye Before the evaluation, the test subjects washed their lower arm skin with water, wiped it with tissue, and left it at room temperature for 10 minutes. Then, the test composition was rubbed on the test subjects' lower arm skin and left at room temperature for 10 minutes. After 10 minutes, the presence or absence of residue was checked with the naked eye and evaluated as follows.

[0069] -O: White residue is visible -X: No white residue visible.

[0070] After the evaluation, the skin to which the sample composition was applied was washed with water and wiped with tissue, and then a one-hour delay was allowed until the next evaluation.

[0071] Evaluation method 2: Niacinamide residue evaluation using a colorimeter Before the evaluation, the skin of the lower arm of the test subject was washed with water, wiped with tissue, and left at room temperature for 10 minutes. Then, the site to which the sample composition was to be applied (i.e., the skin of the lower arm) was marked in four directions with a black name pen, and the central part was measured with a chromameter to measure the initial value L0.

[0072] The sample composition was rubbed onto the skin of the lower arm of the test subject, and then left at room temperature for 10 minutes. The center portion was then measured with a color difference meter to obtain a measurement value L. e The measured value L e The difference between the initial value L0 and the evaluation value ΔL was recorded.

[0073] After the evaluation, the skin to which the sample composition was applied was washed with water and wiped with tissue, and then a one-hour delay was allowed until the next evaluation.

[0074] Experimental Example 1. Evaluation of the effect of citric acid on improving the skin absorption of niacinamide A composition containing niacinamide and citric acid was prepared according to the composition and content (wt %) in Table 1 below.

[0075] Specifically, solutions were prepared containing 5 wt% niacinamide and citric acid in various molar ratios, with the remainder being purified water, totaling 100 wt%. The solutions were dissolved by stirring at 80°C for 10 minutes, and then cooled to room temperature to prepare compositions containing niacinamide and citric acid.

[0076] Thereafter, the residual amount of niacinamide was evaluated using the above-mentioned Evaluation Method 1 and Evaluation Method 2. The results are shown in Table 1.

[0077] [Table 1]

[0078] As shown in Table 1, when the molar ratio of niacinamide and citric acid is 4:1 to 1:4, it can be confirmed that niacinamide does not remain on the skin and there is little color difference on the skin before and after application of the composition.

[0079] On the other hand, if citric acid is not included or its content is insufficient or excessive, niacinamide remains, thereby confirming that the skin color difference is greater than 5 before / after application of the composition.

[0080] Experimental Example 2. Improvement effect of skin absorption of a cosmetic composition containing niacinamide and citric acid Aqueous cosmetic compositions and O / W cosmetic compositions were prepared according to the compositions and contents (wt %) shown in Tables 2 and 3 below.

[0081] Thereafter, the residual amount of niacinamide was evaluated by the above-mentioned Evaluation Method 1 and Evaluation Method 2. The results are shown in Tables 2 and 3.

[0082] [Table 2]

[0083] [Table 3]

[0084] As shown in Tables 2 and 3, the cosmetic compositions prepared in Examples 1 to 3 contain high amounts of niacinamide, but also contain citric acid, which can improve the problem of residual niacinamide. In particular, in the case of Example 2, which contains citric acid and panthenol together, it can be confirmed that excellent skin absorption effect is exhibited even with a small amount of citric acid.

[0085] On the other hand, in Comparative Examples 1 and 3 which did not contain citric acid, and Comparative Examples 2 and 4 which contained insufficient citric acid, it was confirmed that niacinamide was not sufficiently absorbed into the skin and remained as white residue.

[0086] Experimental Example 3. Improvement of skin permeation of niacinamide by citric acid The effect of improving skin permeation of a cosmetic composition containing niacinamide and citric acid was confirmed.

[0087] Cosmetic compositions were prepared according to the compositions and contents (wt%) shown in Tables 4 and 5 below.

[0088] [Table 4]

[0089] [Table 5]

[0090] Then, a percutaneous absorption experiment was carried out using porcine skin.

[0091] Specifically, pig skin was placed in the receptor of a Franz diffusion cell filled with phosphate-buffered saline (pH 7.4, Gibco), with the epidermis facing up (towards the donor) and the dermis facing down (towards the receptor) between the donor and the receptor. 20 μL of each of the compositions of the comparative example and the examples was applied to the pig skin, spread evenly, and placed in a thermo-hygrostat at 37° C. and 50% humidity for 18 hours.

[0092] Thereafter, whether the composition remained on the pig skin was judged by the naked eye using the same criteria as in the above-mentioned evaluation method 1, and the skin tissue was collected after removing the unabsorbed solution. The amount of niacinamide in the skin tissue and receptor was quantified using only the skin tissue exposed to the composition of the pig skin, and the sum of the values ​​was shown in Tables 6 and 7 as the permeation amount.

[0093] [Table 6]

[0094] [Table 7]

[0095] First, as shown in Table 6, it can be seen that, compared to Comparative Example 5 using 20% ​​niacinamide, Examples 4 and 5 have a greater amount of niacinamide permeated into the skin, even though the niacinamide content is only 10%.

[0096] In addition, as shown in Table 7, it can be confirmed that Example 8, which contains citric acid in a cosmetic composition containing a high content of niacinamide as in the present invention, has a significantly higher skin permeation amount of niacinamide than Comparative Example 6, which does not contain citric acid.

[0097] This confirms that the niacinamide of the embodiment can more easily penetrate the lipid layer of the stratum corneum and be delivered to the skin in greater amounts, improving the skin's water absorption. [Industrial Applicability]

[0098] The cosmetic composition according to the present invention contains niacinamide and citric acid together, so that when the cosmetic composition is applied to the skin, niacinamide does not remain as white even after the solvent and preparation evaporate and / or are absorbed, thereby solving usability problems caused by the foreign body sensation and white stains caused by the residue of niacinamide.

Claims

1. Niacinamide; and Citric Acid, The content of the niacinamide is 5% by weight or more based on the total weight of the cosmetic composition, A cosmetic composition, wherein the molar ratio of niacinamide to citric acid is 8:1 to 1:4.

5.

2. The cosmetic composition according to claim 1, characterized in that the skin absorption and / or skin permeation of niacinamide is increased.

3. The cosmetic composition according to claim 1, characterized in that the amount of niacinamide permeated through the skin in the cosmetic composition is 1.5 times or more as compared to a composition not containing citric acid.

4. The cosmetic composition according to claim 1, wherein the content of citric acid is 0.9 to 50 wt % based on the total weight of the cosmetic composition.

5. 2. The cosmetic composition according to claim 1, further comprising panthenol.

6. The cosmetic composition according to claim 5, wherein the content of panthenol based on the total weight of the cosmetic composition is 0.05 wt % or more.

7. 6. The cosmetic composition according to claim 5, wherein the molar ratio of niacinamide to the sum of citric acid and panthenol is from 8:1 to 1:4.

5.

8. The cosmetic composition according to claim 1, wherein the cosmetic composition has a pH of 3.5 to 10.

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