Oil-in-water emulsion cosmetics

Abstract

To provide oil-in-water emulsion cosmetics with a high niacinamide content that offers reduced stickiness, while demonstrating improved firmness, and superior use feels such as richness, springiness, and softness.SOLUTION: Oil-in-water emulsion cosmetics contain the following (A)-(D). (A) 1-10 wt.% of niacinamide, (B) vegetable oil, which is a triglyceride, (C) a higher alcohol fatty acid ester in solid form and (D) a dimer acid phytosteryl derivative.SELECTED DRAWING: None

Description

TECHNICAL FIELD

[0001] The present invention relates to an oil-in-water emulsified cosmetic. BACKGROUND ART

[0002] Niacinamide, also known as nicotin amide / niacin / vitamin B3, is an amide compound of nicotinic acid. Niacinamide is a water-soluble vitamin and one of the B vitamins. Deficiency of niacinamide causes deficiency diseases such as pellagra. Niacinamide is incorporated in external preparations for the treatment of acne (acne vulgaris) and is added to cosmetics for cosmetic purposes. In Japan, it is approved as an active ingredient for improving wrinkles (wrinkle niacin) and an active ingredient with whitening effect (nicotinic acid amide) in quasi-drug cosmetics.

[0003] Niacinamide is often incorporated in skincare cosmetics and the like as an active ingredient for improving wrinkles. In order to achieve wrinkle improvement and impart firmness and elasticity to the skin with niacinamide, a high incorporation amount of about 3 to 7% by weight is required. However, it is known that a high content of niacinamide degrades the feel during use, and it is empirically recognized that a content of 3% by weight or more results in degraded usability.

[0004] The present inventor has experienced that incorporating vegetable oil and fat into the composition of an oil-in-water emulsified cosmetic can achieve excellent usability characterized by "plump skin", "rich body" and "soft texture".

[0005] When the present inventor studied development of a quasi-drug by further incorporating 5% of niacinamide as a main ingredient into an oil-in-water emulsified cosmetic containing vegetable oil and fat, problems occurred in that the sticky feeling peculiar to niacinamide was emphasized in the use experience, and the "plump feel", "rich body" and "soft texture" provided by the vegetable oil and fat were impaired. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0006] The present invention aims to provide a cosmetic product that is an oil-in-water emulsion cosmetic containing a high amount of niacinamide, which suppresses stickiness while improving firmness and providing excellent usability in terms of richness, suppleness, and softness. [Means for solving the problem]

[0007] The means for solving the problems of the present invention are as follows. 1. An oil-in-water emulsion cosmetic containing the following (A) to (D). (A) Niacinamide 1-10% by weight (B) Triglycerides in vegetable oils (C) Solid higher alcohol fatty acid esters (D) Phytosteryl dimer acid derivative 2. The oil-in-water emulsion cosmetic according to 1, wherein (C) is one or more selected from cetyl palmitate, myristyl myristate, and stearyl stearate. 3. An oil-in-water emulsion cosmetic according to 1. or 2., comprising 0.1 to 5% by weight of (C) and 0.01 to 3% by weight of (D). [Effects of the Invention]

[0008] The oil-in-water emulsion cosmetic of the present invention can improve firmness while suppressing stickiness, and offers excellent usability in terms of richness, suppleness, and softness. The oil-in-water emulsion cosmetic of the present invention can achieve both the seemingly contradictory effects of "suppleness" and "softness" and "firmness." [Modes for carrying out the invention]

[0009] The present invention relates to an oil-in-water emulsion cosmetic comprising the following (A) to (D). (A) Niacinamide 1-10% by weight (B) Triglycerides in vegetable oils (C) Solid higher alcohol fatty acid esters (D) Phytosteryl dimer acid derivative In this specification, the notation "X~Y" (where X and Y are numerical values) refers to a numerical range that includes both ends of that range.

[0010] (A) Niacinamide (A) Niacinamide, the component, is an amide compound of nicotinic acid and is a water-soluble vitamin also known as nicotinamide (vitamin B3 / niacin). Niacinamide may be an extract from natural products (such as rice bran) or synthesized by known methods. Specifically, those listed in the 15th edition of the Japanese Pharmacopoeia 2008 can be used. In addition to its wrinkle-improving effect, niacinamide is known to promote blood circulation, improve rough skin, inhibit melanin production, and have a whitening effect.

[0011] In the cosmetic composition of the present invention, the content of component (A) is 1 to 10% by weight of the total cosmetic composition. The content of (A) is preferably 2% by weight or more, more preferably 3% by weight or more, even more preferably 4% by weight or more, preferably 9% by weight or less, more preferably 8% by weight or less, even more preferably 7% by weight or less, and even more preferably 6% by weight or less. The content of (A) niacinamide is preferably 3 to 7% by weight of the total cosmetic composition.

[0012] (B) Triglycerides in vegetable oils Component (B) is a vegetable oil (vegetable fat) obtained from plants, which is a triglyceride in which one glycerol molecule is bonded to three fatty acids, and may be either a liquid oil or a solid fat at room temperature. Even if it is a vegetable oil, a vegetable oil that is not a triglyceride, such as jojoba oil which is an ester of an unsaturated fatty acid and an unsaturated alcohol, is not component (B) of the present invention.

[0013] (B) Examples of vegetable oils that are triglycerides include macadamia nut oil, meadowfoam oil, sunflower oil, coconut oil, olive oil, avocado oil, kukui nut oil, and shea butter, and one or more of these can be used in combination. In the cosmetic composition of the present invention, the content of component (B) is preferably 1 to 10% by weight of the total cosmetic composition. The content of (B) is preferably 2% by weight or more, more preferably 3% by weight or more, preferably 9% by weight or less, more preferably 8% by weight or less, even more preferably 7% by weight or less, and even more preferably 6% by weight or less, based on the total cosmetic composition. The content of vegetable oil which is (B) triglyceride is preferably 2 to 6% by weight of the total cosmetic composition.

[0014] (C) Solid higher alcohol fatty acid esters Component (C) is a solid higher alcohol fatty acid ester. Herein, in this specification, "solid" means having a melting point of 30°C or higher. Examples of component (C) include cetyl palmitate (melting point 55°C), myristyl myristate (melting point 41°C), and stearyl stearate (melting point 62°C), and one or more of these can be used in combination. Cetyl palmitate (melting point 55°C), myristyl myristate (melting point 41°C), and stearyl stearate (melting point 62°C), which are higher alcohol fatty acid esters with melting points of 40 to 65°C, are preferred. In the cosmetic composition of the present invention, the content of component (C) is preferably about 0.1 to 5% by weight of the total cosmetic composition. The content of (C) is more preferably 0.2% by weight or more, even more preferably 0.3% by weight or more, even more preferably 4% by weight or less, even more preferably 3% by weight or less, and even more preferably 2% by weight or less, based on the total cosmetic composition. The content of solid higher alcohol fatty acid ester (C) is preferably 0.3 to 2% by weight of the total cosmetic composition.

[0015] (D) Phytosteryl dimer acid derivative Component (D) is a derivative of a phytosterol ester of dimer acid. Dimer acid is an abbreviation for dimer linoleic acid, and is a linoleic acid dimer obtained by polymerizing two molecules of linoleic acid [(9Z,12Z)-octadeca-9,12-dienoic acid] or other unsaturated fatty acids. In addition to the linoleic acid dimer, the products of the polymerization reaction of linoleic acid include unreacted linoleic acid, trimers, and highly polymerized linoleic acid polymers. The content of linoleic acid dimers can be increased to 90% by weight or more by molecular distillation. Furthermore, the unsaturated bonds of the obtained linoleic acid dimers can be stabilized by adding hydrogen. These hydrogenated linoleic acid dimers are generally called hydrogenated dimer acids. For the synthesis of the phytosteryl dimer acid derivative, which is component (D), either these dimer acids or hydrogenated dimer acids can be used as dimer dilinoleic acid, but from the viewpoint of oxidative stability, hydrogenated dimer acids are more preferable. Commercially available hydrogenated dimer acids, such as Unikema's PRIPOL1006, PRIPOL1009, PRIPOL1025, etc., can be used.

[0016] Phytosterols are a general term for sterols found in plants, and the main components include β-sitosterol, stigmasterol, campesterol, and brassicasterol. The phytosterols used in the synthesis of the phytosteryl dimer acid derivative, which is component (D), are not limited to these, and any sterols obtained from plants can be used without particular restriction. A mixture of multiple phytosterols may also be used.

[0017] (D) Specifically, the components include di(isostearyl / phytosteryl) dimer dilinoleate and dimer dilinoleate (phytosteryl / isostearyl / cetyl / stearyl / behenyl). It was confirmed that the concentration of di(isostearyl / phytosteryl) dimer dilinoleate was 0.01 to 3% by weight, preferably about 0.05 to 0.5% by weight. Preferably, the content of component (D) is about 0.01 to 3% by weight based on the total cosmetic. More preferably, the content of component (D) is 0.02% by weight or more, even more preferably 0.05% by weight or more, and still more preferably 1% by weight or less, particularly preferably 0.6% by weight or less, based on the total cosmetic. Preferably, the content of (D) phytosteryl dimerate derivative is 0.02 to 0.6% by weight based on the total cosmetic.

[0018] In the oil-in-water emulsified cosmetic of the present invention, it is preferable that the content of (D) phytosteryl dimerate derivative does not exceed the content of (C) solid higher alcohol fatty acid ester. If the content of component (D) exceeds the content of component (C), stickiness derived from component (D) becomes noticeable, and there is an increased risk that the effect of (A) niacinamide to suppress stickiness cannot be exhibited, which is not preferable. The weight ratio (C):(D) of the content of (C) solid higher alcohol fatty acid ester to the content of (D) phytosteryl dimerate derivative is preferably 1:0.02 to 1:0.6.

[0019] In addition to components (A) to (D), the cosmetic of the present invention may contain various raw materials commonly used in oil-in-water emulsified cosmetics within a range that does not impair the effects of the present invention, for example, functional ingredients such as emulsifiers, ethanol, moisturizing ingredients, thickeners, chelating agents, pH adjusters, neutralizing agents, preservatives, antioxidants, fragrances, colorants (e.g., cyanocobalamin), cosmetic ingredients (e.g., rosemary extract), and vitamins.

Examples

[0020] The samples used in this test are as follows. <Sample> (A) Niacinamide (B) Vegetable oil that is a triglyceride (vegetable fat and oil) Macadamia nut oil (Nippon Surfactant Industries Co., Ltd., NIKKOL Macadamian Nut Oil, Macadamia nut oil) Meadowfoam seed oil (Croda Japan, CROPURE MEADOWFOAM-LQ, Meadowfoam seed oil) Sunflower oil (International Flora Technologies, Ltd. (USA), FLORASUN 90, sunflower seed oil) Coconut oil (Nikko Chemicals, NIKKOL Trifat C-24, coconut oil)

[0021] (C) Solid higher alcohol fatty acid esters Cetyl palmitate (BASF Japan, Cutina CP-JP, Cetyl palmitate): (Melting point 55℃) Myristyl myristate (Nikko Chemicals, NIKKOL MM, myristyl myristate): (melting point 41℃) Stearyl stearate (Higher Alcohol Industry, Amlepus SS, Stearyl stearate): (Melting point 62℃) (D) Phytosteryl dimer acid derivative Dimer dilinoleate di(isostearyl / phytosteryl) (Nippon Seika, LUSPLAN PI-DA, Dimer dilinoleate di(isostearyl / phytosteryl)) Dimer Dilinoleate (Phytosteryl / Isostearyl / Cetyl / Stearyl / Behenyl) (Nippon Seika, Plandool-S, Dimer Dilinoleate (Phytosteryl / Isostearyl / Cetyl / Stearyl / Behenyl))

[0022] Jojoba oil (Koei Kogyo, refined jojoba oil, jojoba oil: not triglycerides) Hydrogenated lecithin (Nippon Surfactant Industry, NIKKOL Lesinol S-10M, Hydrogenated Lecithin) Carbomer (Wako Pure Chemical Industries, Hibiscus Wako 105, Carbomer) Sclerotium gum (Alban Muller International, AMIGEL) Alcaligenes-producing polysaccharides (Hakuto, Alkasiran, Alcaligenes-producing polysaccharides) Lauroyl glutamate di(octyldodecyl / phytosteryl / behenyl) (Ajinomoto, Eldew PS-306, Lauroyl glutamate di(octyldodecyl / phytosteryl / behenyl)) Macadamia nut fatty acid phytosteryl (Nippon Seika, Plandool-MAS, Macadamia nut fatty acid phytosteryl) Dimethicone (Toray Dow Corning, DOWSIL™ SH 200 C Fluid 50 cSt, Dimethicone) Polysorbate 60 (Nippon Surfactant Industry, NIKKOL TS-10V, Polysorbate 60) SIMULGEL EG (manufactured by SEPPIC, a mixed ingredient containing (sodium acrylate / sodium acryloyldimethyl taurate) copolymer, isohexadecane, polysorbate 80, water, and sorbitan oleate)

[0023] <Preparation method> Using the compositions shown in Tables 1-3, the aqueous phase and the oil phase containing the emulsifier (SIMULGEL EG) were heated to 85°C, and the aqueous phase was slowly added to the oil phase while stirring with a homomixer. After cooling to 35°C, the mixture was neutralized with potassium hydroxide to prepare each oil-in-water emulsion cosmetic.

[0024] [Table 1]

[0025] [Table 2]

[0026] [Table 3]

[0027] <Testing Method> The oil-in-water emulsion cosmetic obtained using the method described above was evaluated for "firmness," "stickiness," "softness," "richness," and "moisture" using the following evaluation methods. • Firmness Based on the consensus of three expert panelists, a sensory evaluation was conducted on the firmness of each oil-in-water emulsion cosmetic immediately after applying approximately 0.3 mL to the inner forearm, using the scoring method described below, and the following scores were assigned. ◎: Feels firm ○: Slightly firm feeling △: Slightly firm feeling ×: Does not feel firm. Stickiness Based on the consensus of three expert panelists, a sensory evaluation was conducted on the stickiness immediately after applying approximately 0.3 mL of each oil-in-water emulsion cosmetic to the inner forearm, using the scoring method described below, and the following scores were assigned. ◎: Does not feel sticky ○: I hardly feel any stickiness. △: Slightly sticky ×: Feels sticky

[0028] • Richness Based on the consensus of three expert panelists, approximately 0.3 mL of each oil-in-water emulsion cosmetic was dispensed onto the inner forearm, and a sensory evaluation was conducted on the richness of the texture when spread, using the scoring method described below. The following scores were assigned. Richness refers to a feeling of thickness when applied, where the thickness of the product is felt, and there is a sensation that the hand does not come into contact with the skin. ◎: Has a rich flavor. ○: Slightly rich in flavor. △: Slightly noticeable richness ×: Does not have a rich flavor. • Chewy texture Based on the consensus of three expert panelists, a sensory evaluation was conducted on the feeling of suppleness (a feeling of the hand sticking to the skin) immediately after applying approximately 0.3 mL of each oil-in-water emulsion cosmetic to the inner forearm, using the scoring method described below, and the following scores were assigned. ◎: Feels chewy ○: Slightly chewy texture △: Slightly chewy texture ×: Does not feel chewy. • Softness Based on the consensus of three expert panelists, approximately 0.3 mL of each oil-in-water emulsion cosmetic was applied to the inner side of the forearm, and a sensory evaluation of the immediate skin softness was conducted using the scoring method described below, resulting in the following scores. ◎: Feels soft ○: Slightly soft △: Slightly soft ×: Does not feel soft.

[0029] "result" From the results of Example 1 and Comparative Examples 1-4, it was confirmed that (A) niacinamide contributes to firmness, (B) vegetable oils contribute to softness, richness, and suppleness, (C) cetyl palmitate contributes to firmness and richness, and (D) di(isostearyl / phytosteryl) dimer dilinoleate contributes to suppressing stickiness and firmness. The results from Examples 1-4 confirmed that (B) vegetable oils such as macadamia nut oil, meadowfoam oil, sunflower oil, and coconut oil produced similar effects. The results from Examples 1, 8, and 9 confirmed that (C) solid higher alcohol fatty acid esters such as cetyl palmitate, myristyl myristate, and stearyl stearate produced similar effects.

[0030] The results from Example 1 and Comparative Examples 5 and 6 confirmed that substituting (C) solid higher alcohol fatty acid ester with other solid higher alcohols or fatty acids did not yield the same effect. The results from Examples 1 and 12 and Comparative Examples 7 and 8 confirmed that the phytosteryl derivative of (D) dimer acid, di(isostearyl / phytosteryl) dimer dilinoleate and dimer dilinoleate (phytosteryl / isostearyl / cetyl / stearyl / behenyl), had similar effects, and that substituting them with other ester oils such as triethylhexanoin or isostearyl isostearate did not yield the same effects.

[0031] From the results of Examples 1, 5, 6, and 7, it was confirmed that the concentration of (C) cetyl palmitate, a solid higher alcohol fatty acid ester, is about 0.1 to 5% by weight, preferably about 0.3 to 2% by weight. From the results of Examples 1, 10, and 11, it was confirmed that the concentration of (D) di(isostearyl / phytosteryl) dimer dilinoleate is about 0.01 to 3% by weight, preferably about 0.05 to 0.5% by weight.

[0032] Formula Example 1: Emulsion (Quasi-drug) (Weight %) 1.Water Residual 2. Niacinamide 5 3. Carbomer 0.05 4. Sclerotium gum 0.02 5. Alcaligenes-produced polysaccharide 0.01 6. BG 7 7. Pentylene glycol 1.5 8. Phenoxyethanol 0.3 9. Ethylhexylglycerin 0.1 10. Citric acid (appropriate amount) 11. Macadamia nut oil 8 12. Hydrogenated lecithin 0.4 13. Lauroyl glutamate Di(octyldodecyl / phytosteryl / behenyl) 4 14. Macadamia nut fatty acid phytosteryl 0.8 15. Cetyl palmitate 0.8 16. Glycerin 10 17. Polysorbate 60 0.3 18. Dimethicone 2 19. SIMULGEL EG 0.7 20. Dimer dilinoleate di(isostearyl / phytosteryl) 0.1 21. Tocopherol 0.01 22. K hydroxide 0.01 A lotion of Formulation Example 1 was prepared by conventional methods. The resulting lotion (oil-in-water emulsion cosmetic) was non-greasy, had excellent firmness, richness, suppleness, and softness. This lotion achieved a balance between "suppleness" and "softness" and "firmness," which are generally considered to be contradictory effects.

Claims

1. An oil-in-water emulsion cosmetic comprising the following (A) to (D), characterized in that the content of component (D) does not exceed the content of component (C). (A) Niacinamide 1-10% by weight (B) Triglycerides in vegetable oils (C) Solid higher alcohol fatty acid ester 0.1-5% by weight (D) Phytosteryl dimer dilinoleate derivative

2. The oil-in-water emulsion cosmetic composition according to claim 1, wherein (C) is one or more selected from cetyl palmitate, myristyl myristate, and stearyl stearate.

3. The oil-in-water emulsion cosmetic composition according to claim 1 or 2, wherein the weight ratio (C):(D) of the content of component (C) to the content of component (D) is 1:0.02 to 1:0.6.

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