Skin external preparation

Abstract

To provide a skin external preparation which suppresses a sticky sensation during application and a squeaking sensation after application attributable to niacinamide, and which further exhibits excellent stability with time.SOLUTION: A skin external preparation according to the present invention is characterized by containing the following components (A) and (B): (A) niacinamide; and (B) an alkyl glucoside / higher alcohol mixture.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an external skin preparation that is effective in inhibiting and improving wrinkles and pigmentation on the skin, suppresses stickiness upon application and a squeaky feeling after application, and has excellent compatibility with the skin and stability over time. [Background technology]

[0002] Aging, ultraviolet rays, and dryness change the morphology of the skin, causing wrinkles and pigmentation, and various topical skin preparations have been developed to improve these conditions. In particular, in recent years, niacinamide (also known as nicotinamide) has begun to be recognized as an ingredient that can prevent wrinkles and pigmentation, and topical skin preparations containing high concentrations of niacinamide have been developed (Patent Documents 1 and 2).

[0003] Niacinamide is an amide compound of nicotinic acid, also known as niacin or vitamin B3. Niacinamide is used as an ingredient in topical medications to treat acne (acne vulgaris) and in cosmetics for cosmetic purposes. In Japan, it is also approved as an active ingredient in quasi-drugs for wrinkle improvement (wrinkle niacin) and for cosmetic effects (nicotinamide).

[0004] As mentioned above, niacinamide is often blended as an active ingredient in skin care cosmetics and the like, but in order to produce more effective cosmetics, it is required to blend it in at a high concentration.

[0005] However, topical skin preparations containing high amounts of niacinamide are known to have a poor feel when used, with some complaining of stickiness upon application and a dry, squeaky feeling after application. This is particularly noticeable when used in oil-in-water emulsion cosmetics, and the loss of the refreshing feel that is characteristic of oil-in-water emulsions has often been cited as a problem.

[0006] Furthermore, although a high concentration of niacinamide has been shown to have a certain degree of effect in inhibiting wrinkles and pigmentation, the effect has not been satisfactory. To further complement the effects of inhibiting and improving wrinkles and pigmentation, physiologically active ingredients such as ascorbic acid derivatives are sometimes used in combination, but the effect is not sufficient, and in some cases, the combination can even impair the stability of the formulation. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2022-129777 [Patent Document 2] Japanese Patent Publication No. 2022-138175 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention relates to a topical skin preparation containing niacinamide, which is stable and free from stickiness upon application or a squeaky feeling after application, has good compatibility with the skin, and is excellent in inhibiting and improving wrinkles and pigmentation on the skin. [Means for solving the problem]

[0009] The present inventors have discovered that by blending component (A) niacinamide and component (B) an alkyl glucoside / higher alcohol mixture, a topical skin preparation can be produced that is free from stickiness upon application or a squeaky feeling after application, has good compatibility with the skin, and exhibits an excellent feel when used, while also suppressing changes in viscosity over time, thereby completing the present invention.

[0010] The first aspect of the present invention is a skin external preparation characterized by containing the following ingredients (A) and (B): (A) Niacinamide (B) Alkyl glucoside / higher alcohol mixture

[0011] The second aspect of the present invention is the topical skin preparation of the first aspect of the present invention, characterized in that the alkyl glucoside / higher alcohol mixture of component (B) is selected from an arachidyl glucoside / arachidyl alcohol / behenyl alcohol mixture or a cetearyl glucoside / cetearyl alcohol mixture. When component (B) is the above-mentioned compound, the topical skin preparation is one that further reduces stickiness upon application and squeaky feeling after application, and therefore corresponds to this preferred embodiment.

[0012] The third aspect of the present invention is the topical skin preparation according to the first or second aspect of the present invention, characterized in that it further contains a water-soluble polymer as component (C). The addition of component (C) results in a highly stable topical skin preparation in which viscosity changes over time are suppressed, and this corresponds to this preferred embodiment.

[0013] The fourth aspect of the present invention is the topical skin preparation according to any one of the first to third aspects of the present invention, further comprising undecylenoylphenylalanine or zinc gluconate as component (D). By including component (D), the topical skin preparation has excellent compatibility with the skin after application, and therefore corresponds to this preferred embodiment. [Effects of the Invention]

[0014] The present invention provides an external skin preparation that, by containing niacinamide and an alkyl glucoside / higher alcohol mixture, suppresses stickiness upon application and a squeaky feeling after application, has excellent compatibility with the skin, and further has excellent stability with little change in viscosity over time during storage. DETAILED DESCRIPTION OF THE INVENTION

[0015] The components (A) to (D) constituting the topical skin preparation of the present invention, as well as the form of the topical skin preparation of the present invention, will be specifically explained below.

[0016] [Ingredient (A): Niacinamide] Niacinamide used in the topical skin preparation of the present invention is an amide compound of nicotinic acid (niacin / vitamin B3). Niacinamide is a water-soluble vitamin and can be obtained by extraction from natural products (such as rice bran) or by synthesis using known methods. In addition to its wrinkle-reducing effect, niacinamide is known to promote blood circulation, improve rough skin, and inhibit melanin production.

[0017] The content of niacinamide as component (A) in the present invention is not particularly limited, but in order to obtain a skin wrinkle improvement effect similar to that of quasi-drugs, the content is 3% by mass or more, preferably 3 to 10% by mass, more preferably 3 to 7% by mass, and particularly preferably 5 to 7% by mass, based on the total amount of the topical skin preparation.

[0018] [Component (B): Alkyl glucoside / higher alcohol mixture] The component (B) used in the present invention is not particularly limited as long as it is a mixture of an alkyl glucoside and a higher alcohol, and one type may be used alone, or two or more types may be used in combination.

[0019] (Alkyl glucoside) The alkyl glucoside used in the present invention is a nonionic surfactant in which a sugar and a higher alcohol are glycosidicly bonded, and is not particularly limited as long as it is one that is normally used in cosmetics.

[0020] The number of carbon atoms in the alkyl group constituting the alkyl glucoside is not particularly limited, and is from 6 to 30. Examples of alkyl glucosides include lauryl glucoside, capryl glucoside, (caprylyl / capryl) glucoside, myristyl glucoside, decyl glucoside, cetearyl glucoside, octyl glucoside, heptyl glucoside, nonyl glucoside, coconut oil alkyl glucoside, arachidyl glucoside, (C12-20) alkyl glucoside, and the like, with arachidyl glucoside and cetearyl glucoside being more preferred.

[0021] (higher alcohol) The higher alcohol used in the present invention is not particularly limited as long as it is one that is commonly used in cosmetics, and is preferably a linear or branched aliphatic alcohol having 14 to 22 carbon atoms. Examples of such higher alcohols include myristyl alcohol, cetyl alcohol, stearyl alcohol, cetearyl alcohol, arachidyl alcohol, behenyl alcohol, (C14-22) alcohol, and coconut alcohol. Of these, arachidyl alcohol, behenyl alcohol, and cetearyl alcohol are more preferred.

[0022] The alkyl glucoside / higher alcohol mixture of the present invention is preferably an arachidyl glucoside / arachidyl alcohol / behenyl alcohol mixture or a cetearyl glucoside / cetearyl alcohol mixture, since these result in an external skin preparation that is more stable over time.

[0023] Commercially available alkyl glucoside / higher alcohol mixtures of component (B) can be used, such as MONTANOV 202 (trade name, manufactured by SEPPIC) as an arachidyl glucoside / arachidyl alcohol / behenyl alcohol mixture and MONTANOV 68 MB (trade name, manufactured by SEPPIC) as a cetearyl glucoside / cetearyl alcohol mixture.

[0024] The amount of the alkyl glucoside / higher alcohol mixture (component (B)) in the cosmetic of the present invention is preferably 1% by mass or more, more preferably 2% by mass or more. The upper limit is preferably 8% by mass or less, more preferably 6% by mass or less. If the amount is less than 1% by mass, it is difficult to achieve stability over time, while if the amount is more than 8% by mass, the effect commensurate with the amount may not be obtained.

[0025] [Component (C): Water-soluble polymer] The topical skin preparation of the present invention can further contain a water-soluble polymer as component (C) to achieve a formulation with high stability over time. This polymer can be used alone or in combination with two or more other polymers. Examples of water-soluble polymers (component (C)) include aqueous or amphiphilic polymers containing acrylamide, acryloyldimethyltaurine, or salts thereof as structural units, (acrylates / C10-30 alkyl acrylate) crosspolymers, carbomer, xanthan gum, Caesalpinia spinosa gum, and glucomannan. The inclusion of these specific thickeners can suppress viscosity changes over time in the topical skin preparation containing niacinamide (component (A)). Furthermore, when applied to the skin, the agent exhibits an excellent usability, such as suppressing stickiness during application and squeaky sensation after application, while maintaining the effects of niacinamide.

[0026] Specific examples of the water-soluble polymer of component (C) include (sodium acrylate / sodium acryloyldimethyl taurate) copolymer, (hydroxyethyl acrylate / sodium acryloyldimethyl taurate) copolymer, (sodium acrylate / acryloyldimethyl taurate / dimethylacrylamide) crosspolymer, (acrylamide / sodium acryloyldimethyl taurate) copolymer, polyacrylate-13 (a copolymer of acrylic acid, acrylic acid amide, sodium acrylate, and sodium acryloyldimethyl taurate), polyacrylate crosspolymer-6 (acryloyldimethyl Examples of such surfactants include ammonium taurate, dimethylacrylamide, a copolymer of lauryl methacrylate and laureth-4 methacrylate crosslinked with trimethylolpropane triacrylate, polyacrylamide, (acrylamide / ammonium acrylate) copolymer, (acrylates / C10-30 alkyl acrylate) crosspolymer, carbomer, xanthan gum, Caesalpinia spinosa gum, and glucomannan. Of these, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, polyacrylamide, and xanthan gum are preferably used.

[0027] Commercially available products can be used as the water-soluble polymer of component (C), such as SIMULGEL EG QD (containing sodium acrylate / sodium acryloyldimethyltaurate copolymer), SEPIGEL 305 (containing polyacrylamide), and SOLAGUM AX (containing xanthan gum), all manufactured by SEPPIC.

[0028] The amount of the water-soluble polymer (component (C)) in the topical skin preparation of the present invention is preferably 0.1% by mass or more, more preferably 0.3% by mass or more. The upper limit is preferably 3.0% by mass or less, more preferably 2.5% by mass or less. If the amount is less than 0.1% by mass, it is difficult to achieve stability over time, while if the amount is more than 3.0% by mass, the effect commensurate with the amount may not be obtained.

[0029] [Component (D): undecylenoylphenylalanine or zinc gluconate] The external skin preparation of the present invention can contain undecylenoylphenylalanine or zinc gluconate as component (D) because these ingredients can provide excellent skin care effects.

[0030] As component (D), commercially available products can be used, such as SEPIWHITE MSH QD (undecylenoylphenylalanine) and SEPITONIC M3.0 (containing zinc gluconate) manufactured by SEPPIC.

[0031] The amount of component (D) in the cosmetic of the present invention is preferably 0.01% by mass or more, more preferably 0.03% by mass or more. The upper limit is preferably 1.0% by mass or less, more preferably 0.8% by mass or less. If the amount is less than 0.01% by mass, it is difficult to obtain a skin care effect, while if the amount is more than 1.0% by mass, the effect may not be commensurate with the amount.

[0032] In addition to these essential components, the topical skin preparation of the present invention may contain, as appropriate, components typically used in cosmetics, such as oily raw materials, surfactants other than component (B), polymeric compounds other than component (C), antioxidants, whitening agents and moisturizing agents other than component (A), drugs, ultraviolet absorbers, sequestering agents, proteins, protein hydrolysates or derivatives thereof, amino acids or derivatives thereof, pH adjusters, preservatives, etc.

[0033] Examples of the oil-based raw materials, surfactants other than component (B), polymeric compounds other than component (C), antioxidants, whitening agents and moisturizing agents other than component (A), drugs, ultraviolet absorbers, sequestering agents, proteins, protein hydrolysates or derivatives thereof, amino acids or derivatives thereof, pH adjusters, preservatives, etc. include those similar to those described in WO2022 / 080287.

[0034] The formulation of the topical skin preparation of the present invention is not particularly limited, but an oil-in-water emulsion type is preferred because it has high moisturizing properties and provides a satisfactory feeling of excellent sensation when used. For example, it can be used as a skin care cosmetic such as a lotion, emulsion, cream, lotion, or sunscreen cream. [Example]

[0035] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. Note that all values ​​shown in the tables of the examples are in mass % relative to the total mass of the cosmetic.

[0036] Examples 1 to 6 and Comparative Examples 1 and 2: Oil-in-water emulsion cream Oil-in-water emulsion creams having the formulations shown in Tables 1 and 2 below were prepared by a conventional method, and the stickiness upon application, the squeaky feeling after application, compatibility with the skin after application, and stability over time were evaluated by the methods described below.

[0037] (Method for evaluating stickiness, squeaky feeling, and skin compatibility) Ten panelists evaluated the oil-in-water emulsion creams prepared according to Tables 1 and 2. The panelists performed a sensory evaluation of each sample, focusing on stickiness upon application to the skin, the squeaky feeling after application, and how well it blended into the skin after application.

[0038] (Evaluation criteria for stickiness upon application) 4 points: No sticky feeling when applied 3 points: Almost no stickiness felt when applied 2 points: Sticky feeling when applied 1 point: Very sticky when applied

[0039] (Evaluation criteria for squeaky feeling after application) 4 points: No squeaky feeling after application 3 points: Almost no squeaky feeling after application 2 points: Feels squeaky after application 1 point: Very squeaky feeling after application

[0040] (Evaluation criteria for skin compatibility after application) 4 points: Very good absorption after application 3 points: Good absorption after application 2 points: Does not blend well with the skin after application 1 point: Does not blend well with skin after application

[0041] The average score for each evaluation result was calculated and classified as follows, as shown in Tables 1 and 2. ◎: 3.5 points or more ○: 3.0 points or more to less than 3.5 points △: 2.0 points or more to less than 3.0 points ×: Less than 2.0 points

[0042] (Method for evaluating stability over time) The oil-in-water emulsion creams prepared in Tables 1 and 2 were stored in a thermostatic chamber at 50°C for 4 weeks and evaluated according to the following criteria.

[0043] (Evaluation criteria for stability over time) ◎: Viscosity change was less than ±10% compared to immediately after preparation. Good: Viscosity change was ±10% or more but less than 20% compared to immediately after preparation. △: Viscosity change was ±20% or more but less than ±30% compared to immediately after preparation. ×: The viscosity changed by ±30% or more compared to immediately after preparation.

[0044] [Table 1]

[0045] [Table 2] In Tables 1 and 2, *1MONTANOV 202 *2 MONTANOV 68 MB *3 SIMULGEL EG QD (containing approximately 35% sodium acrylate / sodium acryloyldimethyltaurate copolymer) (trade name, manufactured by SEPPIC) *4 Carbopol ULTZ21 (product name, manufactured by Lubrizol) *5 Leodor MS-165V *6 Leodor SP-S10V (product name, manufactured by Kao Corporation) *7 DECAGLYN 1-SV (product name, manufactured by Nikko Chemicals Co., Ltd.) *8 LANETTE 22 (product name, manufactured by BASF) *9 EMOGREEN L19 *10 SEPIWHITE MSH QD *11 SEPITONIC M3.0 (containing approximately 4.5-5.0% zinc gluconate) (trade name, manufactured by SEPPIC) It was compounded as.

[0046] The results in Tables 1 and 2 clearly show that the oil-in-water emulsion creams of Examples 1 to 6, which contain components (A) and (B), have an excellent feel when used, such as no stickiness upon application or a squeaky feeling after application, and also have little change in viscosity during storage, providing excellent stability over time. Furthermore, it is clear that Examples 1 and 2, which contain component (C), have improved stability over time compared to Example 3, which does not contain component (C), and that Examples 4 to 6, which further contain component (D), have an improved feel when used.

Claims

1. A topical skin preparation characterized by containing the following components (A) and (B): (A) Niacinamide (B) Alkyl glucoside / higher alcohol mixture

2. 2. The external preparation for skin according to claim 1, wherein component (B) is selected from the group consisting of an arachidyl glucoside / arachidyl alcohol / behenyl alcohol mixture and a cetearyl glucoside / cetearyl alcohol mixture.

3. 3. The external skin preparation according to claim 1, further comprising a water-soluble polymer as component (C).

4. 4. The external skin preparation according to claim 1, further comprising undecylenoylphenylalanine or zinc gluconate as component (D).

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