Oil-based emulsions in water

Abstract

To provide an oil-in-water emulsion composition that contains nicotinamide, gives skin good resilience and firmness, has a good feeling of use with little stickiness, and has high emulsion stability.SOLUTION: An oil-in-water emulsion composition contains the following components: (A) nicotinamide 1-10 mass%, (B) hydrogenated phospholipid 0.1-1.5 mass%, (C) starch aluminium octenyl succinate 0.1-1.0 mass%, (D) water-soluble polymer 0.02-1.0 mass%, (E) oil-based component that is liquid at 25°C, (F) polyhydric alcohol 5-25 mass%, and (G) water.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an oil-in-water emulsion composition, and particularly to an oil-in-water emulsion composition containing nicotinamide.

Background Art

[0002] Elements that greatly affect the aesthetic appearance of the skin include wrinkles, sagging, spots, and pigmentation. Although many drugs have been proposed as agents for preventing and improving these wrinkles and sagging, among them, nicotinamide, which is a vitamin, is known to have high safety and an anti-skin aging effect (Patent Documents 1 and 2). However, it is known that when a large amount of nicotinamide is contained, there is an undesirable feeling of stickiness, etc. (Patent Document 3).

[0003] Particularly, in cosmetics, unlike pharmaceuticals, sensory properties and stability are important factors. For this reason, various studies have been conventionally made, but an emulsion that contains nicotinamide, has good stability, and has sufficient sensory properties has not been obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide an oil-in-water emulsion composition that contains nicotinamide, is excellent in the effect of imparting firmness and elasticity to the skin, has an excellent feeling of use with little stickiness, and is excellent in emulsion stability. [Means for solving the problem]

[0006] The oil-in-water emulsion composition of the present invention is characterized by containing the following components. (A) Nicotinamide 1-10% by mass (B) Hydrogenated phospholipids 0.1-1.5% by mass (C) Aluminum starch octenyl succinate 0.1-1.0% by mass (D) Water-soluble polymer 0.02~1.0% by mass (E) Oily components that are liquid at 25°C (F) Polyhydric alcohols 5-25% by mass (G)Water

[0007] The above component (D) is characterized by containing xanthan gum and carboxyvinyl polymer.

[0008] The above-mentioned component (F) is characterized by having a content of 5 to 20% by mass.

[0009] The above component (E) is characterized in that it contains lauroyl glutamate diester, and the content of the lauroyl glutamate diester is 0.01 to 1.0% by mass.

[0010] The oil-in-water emulsion composition of the present invention is characterized in that the average particle size of the emulsion droplets is 800 nm or less. [Effects of the Invention]

[0011] The oil-in-water emulsion composition of the present invention contains the above components (A) to (G), and therefore has excellent skin firmness and elasticity-improving effects, a non-greasy feel, and excellent emulsion stability. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below. In this specification, "~" means a range including the numbers before and after it.

[0013] <1> Ingredient (A): Nicotinamide Component (A) in this invention is an amide compound of nicotinic acid (vitamin B3 / niacin), which is a water-soluble vitamin. Nicotinamide may be derived from extracts of natural products (such as rice bran) or synthesized by known methods. Specifically, those listed in the Japanese Pharmacopoeia can be used. Nicotinamide is known for its skin-improving effects, melanin production inhibitory effects, and skin-whitening effects.

[0014] In the present invention, the content of component (A) is 1 to 10% by mass relative to the total amount of the oil-in-water emulsion composition. This improves skin firmness and elasticity while suppressing stickiness. In the present invention, even with a high concentration of nicotinamide, excellent emulsification stability is exhibited, so the content of component (A) is preferably 3 to 10% by mass, and more preferably 4 to 7% by mass.

[0015] <2> Component (B): Hydrogenated phospholipid Component (B) in the present invention is a phospholipid whose unsaturated carbon chain has been saturated by hydrogenation. Examples of hydrogenated phospholipids include hydrogenated phosphatidylcholine (PC), phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, and phosphatidylinositol, as well as hydrogenated lecithins such as soy lecithin and egg yolk lecithin extracted from natural soybeans and egg yolks. Component (B) in the present invention also includes hydrogenated lysophospholipids in which one fatty acid group has been removed from a phospholipid. One or more of the above hydrogenated materials can be used as component (B).

[0016] From the viewpoint of emulsification stability, it is preferable that component (B) contains hydrogenated lecithin. The PC content of the hydrogenated lecithin is, for example, 50 to 90% by mass. As a commercially available product, for example, Nikko Chemicals' Resinol S-10M (hydrogenated soybean phospholipid: PC content 55 to 65% by mass) can be used.

[0017] In the present invention, the content of component (B) is 0.1 to 1.5% by mass based on the total amount of the oil-in-water type emulsion composition. Further, from the viewpoints of improving stickiness and enhancing emulsion stability, the content of component (B) is preferably 0.2 to 1.0% by mass, and more preferably 0.3 to 0.8% by mass.

[0018] <3> Component (C): Aluminum octenyl succinate starch Component (C) in the present invention is a starch derivative obtained by esterifying starch with octenyl succinic acid and adding an aluminum salt. Examples of the starch constituting aluminum octenyl succinate starch include corn starch. Examples of component (C) include aluminum octenyl succinate corn starch. As a commercially available product, for example, DRY-FLO PURE of NOURYON can be mentioned.

[0019] In the present invention, the content of component (C) is 0.1 to 1.0% by mass based on the total amount of the oil-in-water type emulsion composition. Further, from the viewpoints of improving stickiness and emulsion stability, the content of component (C) is 0.1 to 0.8% by mass, and more preferably 0.3 to 0.6% by mass.

[0020] <4> Component (D): Water-soluble polymer Component (D) in the present invention is a general term for polymers that can obtain a thickening effect when made into an aqueous solution and adjusted to a necessary pH. For example, sodium polyacrylate, cellulose ether, calcium alginate, carboxyvinyl polymer, ethylene / acrylic acid copolymer, vinyl pyrrolidone-based polymer, vinyl alcohol / vinyl pyrrolidone copolymer, nitrogen-substituted acrylamide-based polymer, polyacrylamide, cationic polymers such as cationized gellan gum, dimethylacryloammonium-based polymer, acrylic acid methacrylic acid acrylate copolymer, polyoxyethylene (POE) / polyoxypropylene (POP) copolymer, polyvinyl alcohol, hyaluronic acid or its salt, chondroitin sulfate or its salt, silkworm polysaccharide, collagen, pullulan, agar, gelatin, tamarind seed polysaccharide, xanthan gum, carrageenan, high-methoxyl pectin, low-methoxyl pectin, gellan gum, gum arabic, crystalline cellulose, arabinogalactan, karaya gum, tragacanth gum, alginate, albumin, casein, curdlan, gellan gum, dextran, cellulose, polyethyleneimine, polyethylene glycol, high-degree polymerization polyethylene glycol, cationized silicone polymer, etc. can be mentioned. As component (D), one or more of these can be used.

[0021] In the present invention, the content of component (D) is 0.02 to 1.0% by mass, preferably 0.02 to 0.8% by mass, more preferably 0.1 to 0.6% by mass based on the total amount of the oil-in-water type emulsified composition.

[0022] In particular, from the viewpoint of emulsification stability, it is preferable that component (D) contains xanthan gum and carboxyvinyl polymer. Xanthan gum is a polysaccharide obtained by the fermentation action of Xanthomonas campestris bacteria. Carboxyvinyl polymer is an acidic polymer mainly composed of acrylic acid polymer, and commercially available products can be used. The content of xanthan gum is preferably 0.01 to 0.5% by mass, and more preferably 0.02 to 0.4% by mass, based on the total amount of the oil-in-water emulsion composition. The content of carboxyvinyl polymer is preferably 0.01 to 0.5% by mass, and more preferably 0.02 to 0.6% by mass.

[0023] Furthermore, component (D) may contain other water-soluble polymers in addition to xanthan gum and carboxyvinyl polymer. Preferably, the other water-soluble polymer is one or more selected from chondroitin sulfate or its salt, polyethylene glycol, Tremella fuciformis polysaccharide, hyaluronic acid or its salt. Tremella fuciformis polysaccharide is a water-soluble polysaccharide obtained from a mushroom belonging to the Tremellaceae family. Component (D) preferably contains at least Tremella fuciformis polysaccharide as the other water-soluble polymer, and its content is, for example, 0.0001 to 0.01% by mass.

[0024] <5> Ingredient (E): Oily component that is liquid at 25°C Component (E) in the present invention is an oily component having a melting point lower than 25°C and being liquid at 25°C. Examples of oily components that are liquid at 25°C include hydrocarbon oils such as liquid paraffin, α-olefin oligomers, and squalane; ester oils such as isopropyl myristate, myristyl myristate, octyldodecyl myristate, isopropyl palmitate, isopropyl adipate, and di(phytosteryl / octyldodecyl) lauroyl glutamate; vegetable oils such as soybean oil, rice bran oil, jojoba oil, avocado oil, almond oil, olive oil, cocoa oil, sesame oil, peach kernel oil, castor oil, coconut oil, and macadamia nut oil; silicone oils such as methylpolysiloxane, methylphenylpolysiloxane, and methylcyclopolysiloxane; and higher fatty acids such as oleic acid. One or more of these can be used as component (E).

[0025] In the present invention, the content of component (E) is preferably 1.0 to 7.0% by mass, and more preferably 3.0 to 5.0% by mass, based on the total amount of the oil-in-water emulsion composition.

[0026] In particular, from the viewpoint of improving stickiness and emulsification stability, it is preferable that component (E) contains lauroyl glutamate diester. Examples of lauroyl glutamate diester include lauroyl glutamate di(phytosteryl / octyldodecyl). Furthermore, it is more preferable that the lauroyl glutamate diester is contained in an amount of 0.03 to 0.3% by mass relative to the total amount of the oil-in-water emulsion composition. Moreover, the ratio of the content of lauroyl glutamate diester to the content of component (C) described above is preferably (1:5) to (1:30), and more preferably (1:5) to (1:20).

[0027] <6> Ingredient (F): Polyhydric alcohol The component (F) in the present invention can be used without particular limitations as long as it is commonly used in fields such as cosmetics and pharmaceuticals. For example, 1,3-propanediol, 1,2-pentanediol, diethylene glycol, propylene glycol, 1,3-butylene glycol, ethylene glycol, triethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, polyethylene glycol, polypropylene glycol, pentyl glycol, glycerin, diglycerin, pentaerythritol, treitol, arabitol, xylitol, galactitol, sorbitol, lactitol, maltitol, and the like can be used as component (F). One or more of these can be used as component (F).

[0028] Among the polyhydric alcohols mentioned above, it is preferable to use one or more selected from 1,3-butylene glycol, 1,3-propanediol, and glycerin, and it is more preferable to use a combination of 1,3-butylene glycol and glycerin. In the latter case, component (F) preferably contains 1,3-butylene glycol in an amount of 40% by mass or more, and more preferably 50% by mass or more, relative to the total amount of polyhydric alcohol.

[0029] In the present invention, the content of component (F) is 5 to 25% by mass, preferably 5 to 20% by mass, and more preferably 10 to 20% by mass, based on the total amount of the oil-in-water emulsion composition.

[0030] <7> Ingredient (G): Water The component (G) in this invention can be used without particular limitations as long as it is commonly used in fields such as cosmetics and pharmaceuticals. In addition to water, purified water, hot spring water, deep sea water, etc., can be used, and one or more of these can be used as appropriate. The content of component (G) is not particularly limited, but 30 to 70% by mass is preferred.

[0031] Furthermore, the oil-in-water emulsion composition of the present invention may also contain, as needed, water-soluble vitamins, amino acid derivatives, inorganic salts, chelating agents, preservatives, pH adjusters, dyes, water-soluble agents, and other substances. It is also preferable that the oil-in-water emulsion composition of the present invention does not contain anionic surfactants, cationic surfactants, or nonionic surfactants, specifically polyglycerin fatty acid esters and sucrose fatty acid esters.

[0032] The method for producing the oil-in-water emulsion composition of the present invention is not particularly limited. In addition to conventional emulsification, multi-stage emulsification, D-phase emulsification, phase inversion emulsification, liquid crystal emulsification, PIT emulsification, gel emulsification, membrane emulsification, etc., can be selected. The emulsification apparatus is also not particularly limited. In addition to conventional emulsification apparatus such as stirrers, impeller stirring, and homomixers, high-pressure emulsifiers such as Manton-Gorin type high-pressure homogenizers, jet water flow reversal type high-pressure emulsifiers, microfluidizers, nanomizers, and starbursts can also be used. One or more of these can be combined to obtain the desired particle size.

[0033] The oil-in-water emulsion composition of the present invention preferably has an average particle diameter of 800 nm or less, more preferably 300 nm or less, in terms of improving stickiness and suppressing creaming over time. In this invention, "average particle diameter of emulsion particles" refers to the 50% diameter (cumulative median diameter) determined by the laser diffraction-scattering method based on Mie scattering theory. Specifically, it can be measured by creating a volume-based particle size distribution of the emulsion particles using a laser diffraction particle size distribution analyzer and taking the median value as the average particle diameter. As a measurement sample, an emulsion composition dispersed in water can be used. As a laser diffraction particle size distribution analyzer, for example, the Shimadzu Corporation's laser diffraction particle size distribution analyzer "SALD2000" can be used.

[0034] The oil-in-water emulsion composition of the present invention can be formed into various dosage forms by combining it with other components. Specifically, it can be formed into gel, paste, liquid, cream, or solid forms. [Examples]

[0035] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples.

[0036] Table 1 lists the examples and comparative examples, their average particle size, emulsification stability, and user experience. First, the proportions are shown in parts by weight, and the manufacturing method is as follows. 1. Component A, excluding the pH adjuster, was dissolved and stirred, and the pH adjuster was added to it. 2. Component A was heated to 80°C. 3. Component B was heated to 80°C and dissolved, then emulsified using a homomixer (8000 rpm). In Example 2 only, this emulsion was further treated once using a microfluidizer at 124 MPa. 4. While mixing and stirring components A and B, component C was added and the mixture was cooled.

[0037] [Table 1]

[0038] Note 1) Nippon Fine Chemical Company Tremost-TP Note 2) Nikko Chemicals Co., Ltd. Resinol S-10M Note 3) Nippon Seika Co., Ltd. Plandool LG-2 Note 4) NOURYON DRY-FLO PURE

[0039] The "Particle Size Measurement" in Table 1 was performed as follows. Emulsified particles were dispersed in purified water, and the average particle size (median in the volume-based particle size distribution) was measured using a SALD-2000 particle size distribution analyzer (manufactured by Shimadzu Corporation).

[0040] The "emulsification stability" in Table 1 was determined as follows: The formulation was filled into clear glass bottles and stored for 6 months at 40°C and 75% RH. The emulsification state was visually confirmed. ○: No changes in state such as separation or aggregation were observed. △: Slight changes in state such as separation or aggregation are observed. ×: Clear changes in state such as separation and aggregation are observed. Furthermore, in Comparative Examples 3 and 6 (marked with *), the desired emulsified state was not achieved immediately after preparation.

[0041] The "User Experience" ratings in Table 1 were determined as follows: Ten expert panelists used Examples 1 to 3 and Comparative Examples 1, 2, 4, and 5 and answered whether they felt any stickiness. Number of people who felt sticky Rating 0-1 ○ 2-4 △ 5~ × Furthermore, in Comparative Examples 3 and 6 (marked with *), the desired emulsified state was not achieved immediately after preparation, so the user experience was not evaluated.

[0042] Examples 1 to 3 all provided oil-in-water emulsion compositions that exhibited excellent skin firmness and elasticity-enhancing effects, a non-greasy feel, and superior emulsification stability.

Claims

1. An oil-in-water emulsion composition characterized by containing the following components and having an average particle size of 800 nm or less for the emulsion droplets. (A) Nicotinamide 1-10% by mass (B) Hydrogenated phospholipids 0.3-0.8% by mass (C) Aluminum starch octenyl succinate 0.1-1.0% by mass (D) Water-soluble polymer 0.02-1.0% by mass (E) Oily components that are liquid at 25°C (F) Polyhydric alcohol 5-25% by mass (G) Water

2. The oil-in-water emulsion composition according to claim 1, characterized in that the component (D) contains xanthan gum and a carboxyvinyl polymer.

3. The oil-in-water emulsion composition according to claim 1 or 2, characterized in that the content of the aforementioned component (F) is 5 to 20% by mass.

4. The oil-in-water emulsion composition according to any one of claims 1 to 3, characterized in that the component (E) contains lauroyl glutamate diester, and the content of the lauroyl glutamate diester is 0.01 to 1.0% by mass.

5. The oil-in-water emulsion composition according to any one of claims 1 to 4, characterized in that the component (D) further contains Tremella fuciformis polysaccharide.

Images