Skin care products and preparations

Abstract

To provide a skin care agent having an improved moisturizing effect.SOLUTION: A skin care agent according to an embodiment includes a monodisperse nano-emulsion having an average particle size of 18 nm or less, having a size distribution index of 0.14 or less, and not including particles of 100 nm or more. The nano-emulsion includes a water-insoluble functional component, a surfactant, oil, and an aqueous medium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to skin care agents and products. [Background technology]

[0002] Emulsification is known as a method for solubilizing poorly water-soluble substances. For example, Patent Document 1 describes a monodisperse nanoemulsion having an average particle size of 18 nm or less, a particle size distribution index of 0.14 or less, and containing no particles of 100 nm or more. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 005676 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the nanoemulsion described in Patent Document 1 has opened up further avenues for application. As a result of extensive research by the present inventors, it was found that skin care agents containing specific nanoemulsions have excellent moisturizing effects. [Means for solving the problem]

[0005] The present invention includes the following configurations. <1> A skin care agent, It contains a monodisperse nanoemulsion with an average particle size of 18 nm or less, a particle size distribution index of 0.14 or less, and no particles of 100 nm or more. The nanoemulsion is a skin care agent comprising a poorly water-soluble functional ingredient, a surfactant, an oil and an aqueous medium. <2> The poorly water-soluble functional ingredient includes one or more selected from sphingolipids, glycerin ester-based oils, fibrous proteins, and coenzyme Q10. <1> The skin care agent according to claim 1. <3> The poorly water-soluble functional ingredient contains a sphingolipid, The surfactant includes polysorbate 80 and polyoxyethylene castor oil, The oil contains diisostearyl malate. <1> or <2> The skin care agent according to claim 1. <4> The poorly water-soluble functional ingredient contains a glycerin ester-based oil agent, The surfactant includes polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil, The oil contains medium-chain triglycerides. <1> or <2> The skin care agent according to claim 1. <5> <1> ~ <4> A skin care product comprising the skin care agent according to any one of the preceding items. <6> cream, lotion, or toner, <5> 1. A skin care product according to claim 1. [Effects of the Invention]

[0006] According to one aspect of the present invention, a skin care agent having excellent moisturizing effect can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0007] [1. Skin care products] As used herein, the term "skin care agent" refers to an active ingredient that can be incorporated into skin care products and the like. Skin care agents can be manufactured, distributed, or sold as such (without being incorporated into skin care products and the like). In one aspect, the present invention can be said to disclose a nanoemulsion for skin care.

[0008] A skin care agent according to one embodiment of the present invention contains a nanoemulsion. The skin care agent may contain only the nanoemulsion, or the nanoemulsion may be mixed with other substances. Examples of other substances include aqueous media (media containing water, such as ultrapure water, buffer solutions, and physiological saline). When the nanoemulsion is mixed with other substances, the content of the nanoemulsion may be, for example, 20% by mass or more, 50% by mass or more, 70% by mass or more, or 90% by mass or more.

[0009] [1.1. Nanoemulsion] A skin care agent according to one embodiment of the present invention contains a monodisperse nanoemulsion having an average particle size of 18 nm or less, a particle size distribution index of 0.14 or less, and containing no particles of 100 nm or more.

[0010] As used herein, the term "nanoemulsion" refers to a dispersion system of tiny micelles. The skin care agent according to one embodiment of the present invention contains a nanoemulsion, and therefore can impart excellent moisturizing effects to skin care products (creams, emulsions, lotions, etc.). Furthermore, when the skin care agent according to one embodiment of the present invention is applied to lotions, a transparent product can be obtained, further providing the effect of excellent appearance.

[0011] The average particle size of the nanoemulsion is 18 nm or less, preferably 16 nm or less, and more preferably 14 nm or less. If the average particle size of the nanoemulsion is 18 nm or less, the absorption efficiency of the poorly water-soluble functional ingredient described below into the living body can be improved. In this specification, the particle size of the nanoemulsion is the hydrodynamic diameter determined by dynamic light scattering. In this specification, the average particle size of the nanoemulsion is the intensity-based average particle size (Z average). The average particle size is measured, for example, using a Zetasizer Nano ZS (manufactured by Malvern Institutes) in the measurement mode "size-small-vol-cell x 1.SOP".

[0012] The particle size distribution index (PDI) of the nanoemulsion is 0.14 or less, preferably 0.138 or less, and more preferably 0.136 or less. Nanoemulsions with a particle size distribution index of 0.14 or less tend to have an average particle diameter of 18 nm or less. Therefore, such nanoemulsions have excellent stability. The particle size distribution index is calculated based on the particle size distribution. The particle size distribution index is measured, for example, using a Zetasizer Nano ZS (manufactured by Malvern Institutes) in the measurement mode "size-small-vol-cell x 1.SOP".

[0013] Nanoemulsions are monodisperse. Monodisperse means that there is only one peak in the particle size distribution. For example, by measuring the particle size distribution using a Zetasizer Nano ZS (Malvern Institutes), it is possible to determine whether the particle group is monodisperse. If it is not monodisperse, a second or subsequent peak will be displayed, such as "Peak-2" or "Peak-3." Monodisperse nanoemulsions are highly absorbable by the body and have excellent stability.

[0014] Nanoemulsions do not contain particles with a particle size of 100 nm or more, or 80 nm or more, or preferably 50 nm or more. Nanoemulsions that satisfy this condition are said to have high particle homogeneity.

[0015] For simplicity, the present specification uses the expressions "average particle size of the nanoemulsion," "particle size distribution index of the nanoemulsion," and "monodisperse nanoemulsion." Strictly speaking, these expressions are intended to mean "average particle size of the micelles contained in the nanoemulsion," "particle size distribution index of the micelles contained in the nanoemulsion," and "nanoemulsion in which the particle size distribution of the micelles contained is monodisperse."

[0016] The nanoemulsion is preferably an oil-in-water nanoemulsion, which has excellent stability. In one embodiment, the nanoemulsion remains stable at 25° C. for 14 days or more.

[0017] In one embodiment, the nanoemulsion comprises a poorly water-soluble functional ingredient, a surfactant, an oil, and an aqueous medium. Each component will be described below.

[0018] [1.1.1 Poorly water-soluble functional ingredients] The nanoemulsion contains a poorly water-soluble functional ingredient. In one embodiment, the poorly water-soluble functional ingredient is an active ingredient having a moisturizing effect.

[0019] As used herein, "poorly water-soluble" means "slightly soluble," "extremely soluble," or "almost insoluble" as defined in the Japanese Pharmacopoeia, preferably "extremely soluble" and "almost insoluble," and more preferably "almost insoluble." Expressed in terms of solubility, the poorly water-soluble functional ingredient has a solubility in water at 20°C of 10 mg / mL or less, preferably 1 mg / mL or less, and more preferably 0.1 mg / mL or less.

[0020] Although the poorly water-soluble functional ingredient has low solubility in water, it can be dispersed in an aqueous medium by forming a nanoemulsion together with an oil and a surfactant. Therefore, the poorly water-soluble functional ingredient is preferably fat-soluble.

[0021] As used herein, the term "functional ingredient" is not particularly limited as long as it has some function. Examples of functional ingredients include ingredients that provide a specific nutritional or health benefit to a living organism.

[0022] Examples of ingredients that provide nutritional or health benefits include skin-improving ingredients, moisturizing ingredients, anti-aging ingredients, hair-growth ingredients, and hair-growth ingredients used in cosmetics. Specific examples of such poorly water-soluble functional ingredients include sphingolipids, glycerin ester-based oils, fibrous proteins (e.g., collagen, elastin), coenzyme Q10, curcumin, tocotrienols, carotenoids (e.g., α-carotene, β-carotene, lutein, lycopene, astaxanthin, zeaxanthin, cryptoxanthin, fucoxanthin, and xanthophylls), resveratrol, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), fat-soluble vitamins (vitamin A, vitamin D, vitamin E (tocopherol), vitamin K) and their derivatives, sesamin, α-lipoic acid, ferulic acid, and oryzanol. These ingredients may be used alone or in combination.

[0023] Among these, the poorly water-soluble functional ingredient contained in the nanoemulsion is preferably one or more selected from sphingolipids, glycerin ester-based oils, fibrous proteins, and coenzyme Q10.

[0024] Examples of sphingolipids include ceramide, sphingosine, and sphingomyelin. Among these, ceramide is preferred from the viewpoint of obtaining a moisturizing effect. Ceramide is an amide in which a fatty acid is bound to the nitrogen atom of sphingosine. Specific examples of ceramide include ceramide NG (ceramide 2) and ceramide NP (ceramide 3).

[0025] Examples of glycerin ester-based oils include PCA glyceryl oleate and PCA glyceryl isostearate. Among these, PCA glyceryl oleate is preferred from the viewpoint of achieving moisturizing effects. PCA glyceryl oleate is an ester of pyrrolidonecarboxylic acid and glyceryl monooleate, and its INCI name is "PCA Glyceryl Oleate."

[0026] The lower limit of the content of the poorly water-soluble functional component in the nanoemulsion is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. The upper limit of the content of the poorly water-soluble functional component is not particularly limited, but may be, for example, 5% by mass or less. If the content of the poorly water-soluble functional component is within this range, the moisturizing effect is easily improved.

[0027] [1.1.2. Surfactants] Examples of surfactants include polysorbate 80, polyoxyethylene castor oil, polyoxyethylene glyceryl isostearate, polyoxyethylene cetyl ether, and polyoxyethylene lauryl ether carboxylic acid. Among these, one or more selected from polyoxyethylene castor oil, polysorbate 80, and polyoxyethylene glyceryl isostearate are preferred. The use of these surfactants tends to result in nanoemulsion with a small particle size, a narrow particle size distribution, and improved particle size uniformity.

[0028] Polysorbate 80 is a compound with the INCI name "Polysorbate 80."

[0029] Polyoxyethylene castor oil is a compound in which polyoxyethylene is added to castor oil. The polyoxyethylene contained in polyoxyethylene castor oil preferably has an average added mole number of ethylene oxide of 2 to 100 moles, more preferably 10 to 50 moles. An example of polyoxyethylene castor oil is PEG35-castor oil. Hydrogenated polyoxyethylene castor oil may also be used. Examples of hydrogenated polyoxyethylene castor oil include PEG20-hydrogenated castor oil, PEG30-hydrogenated castor oil, PEG35-hydrogenated castor oil, PEG40-hydrogenated castor oil, and PEG50-hydrogenated castor oil.

[0030] Polyoxyethylene glyceryl isostearate is a polyoxyethylene ether of glyceryl isostearate. The polyoxyethylene contained in polyoxyethylene glyceryl isostearate preferably has an average number of moles of ethylene oxide added of 10 to 40 moles, more preferably 14 to 30 moles. Examples of polyoxyethylene glyceryl isostearate include PEG-20 glyceryl isostearate, PEG-25 glyceryl isostearate, and PEG-30 glyceryl isostearate.

[0031] To further improve the stability of the nanoemulsion, two or more types of surfactants may be included. In one embodiment of the present invention, when two or more types of surfactants are included in the nanoemulsion, the ratio of their use is not particularly limited. For example, when polysorbate 80 and polyoxyethylene castor oil are used as a mixture, the mixing ratio may be (1:99) to (99:1). For example, when polyoxyethylene castor oil and polyoxyglyceryl isostearate are used as a mixture, the mixing ratio may be (1:99) to (99:1).

[0032] The lower limit of the surfactant content is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the total nanoemulsion. The lower limit of the surfactant content is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less, based on the total nanoemulsion. If the surfactant content is 10% by mass or more, the poorly water-soluble functional component dissolved in oil tends to be sufficiently mixed with water. If the surfactant content is 40% by mass or less, the nanoemulsion particle size tends to be small, the particle size distribution tends to be narrow, and the particle size uniformity tends to be improved.

[0033] [1.1.3.Oil] The oil is not particularly limited as long as it is an oil that can be normally used in cosmetics. Specific examples of the oil include naturally derived oils (avocado oil, olive oil, sesame oil, almond oil, bergamot oil, camellia oil, evening primrose oil, macadamia nut oil, corn oil, rapeseed oil, persic oil, wheat germ oil, sasanqua oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, tung oil, canola oil, safflower oil, kukui nut oil, grapeseed oil, hazelnut oil, sunflower oil, rosehip oil, pistachio nut oil, palm oil (coconut oil), vegetable squalane, etc.); synthetic oils (medium-chain fatty acid triglycerides, isopropyl myristate, octyldodecyl myristate, diisostearyl malate, liquid paraffin, etc.). Among the naturally occurring oils, vegetable oils are more preferred.

[0034] From the viewpoints of bioabsorbability and solubility of poorly soluble functional ingredients, the oil is more preferably one or more selected from soybean oil, medium-chain fatty acid triglyceride, diisostearyl malate, palm oil (coconut oil), bergamot oil, rosehip oil, and almond oil, and even more preferably one or more selected from diisostearyl malate and medium-chain fatty acid triglyceride. Only one type of oil may be used, or two or more types may be mixed and used.

[0035] The freezing point of the oil is more preferably 25° C. or lower. Such oil does not solidify at room temperature (25° C.), improving the stability of the nanoemulsion.

[0036] By using oil, it is possible to obtain a stable nanoemulsion with small particle size of emulsified particles.

[0037] [1.1.4.Aqueous medium] The term "aqueous medium" generally refers to a medium containing water. Specific examples of aqueous media include water (ultrapure water, distilled water, ion-exchanged water, etc.), buffer solutions (phosphate buffer solutions, etc.), and physiological saline. Only one type of aqueous medium may be used, or two or more types may be mixed and used.

[0038] The lower limit of the content of the aqueous medium contained in the nanoemulsion is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on the total weight of the nanoemulsion. The upper limit of the content of the aqueous medium contained in the nanoemulsion is preferably 99.9% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, based on the total weight of the nanoemulsion. If the content of the aqueous medium contained in the nanoemulsion is 50% by mass or more, the nanoemulsion can be suitably formed. Furthermore, if the content of the aqueous medium contained in the nanoemulsion is 99.9% by mass or less, the concentration of the poorly water-soluble functional ingredient will not be too low.

[0039] [1.1.5. Suitable Combinations of Ingredients] The present inventors have also discovered a suitable combination of components that forms a nanoemulsion. Skin care agents containing nanoemulsions formed by this combination tend to have improved moisturizing effects.

[0040] In Combination 1, each component constituting the nanoemulsion satisfies the following conditions. The poorly water-soluble functional component includes a sphingolipid (such as ceramide). In one embodiment, no poorly water-soluble functional component other than a sphingolipid is included. The surfactants include polysorbate 80 and polyoxyethylene castor oil (such as PEG35-castor oil). In one embodiment, no surfactants other than polysorbate 80 and polyoxyethylene castor oil are included. The oil comprises diisostearyl malate. In one embodiment, no oil other than diisostearyl malate is included.

[0041] In Combination 1, it is more preferable that each component satisfies the following conditions (ia) and (ii-a), and even more preferable that each component satisfies conditions (ia), (ii-a), and (iii-a). If a nanoemulsion is prepared with such a composition, the average particle size can be reduced, the particle size distribution can be narrowed, and the uniformity of the particle size can be improved. (ia) The value of "total weight of polysorbate 80 and polyoxyethylene castor oil / weight of oil" is 9.20 to 240. (ii-a) The value of "total weight of polysorbate 80 and polyoxyethylene castor oil / weight of oil and poorly water-soluble functional ingredient" is 5.20 to 200. (iii-a) If the LogP of the poorly water-soluble functional ingredient is 4.2 or more, the value of "weight of oil / weight of poorly water-soluble functional ingredient" is [-0.38 × (LogP of poorly water-soluble functional ingredient) + 5.169] to 2000. If the LogP of the poorly water-soluble functional ingredient is less than 4.2, the value of "weight of oil / weight of poorly water-soluble functional ingredient" is [-4.955 × (LogP of poorly water-soluble functional ingredient) + 23.56] to 2000.

[0042] In condition (ia), the lower limit of the value of "total weight of polysorbate 80 and polyoxyethylene castor oil / weight of oil" is more preferably 9.40 or more, even more preferably 9.60, even more preferably 10 or more, and particularly preferably 20 or more.

[0043] In condition (ii-a), the lower limit of the value of "total weight of polysorbate 80 and polyoxyethylene castor oil / weight of oil and poorly water-soluble functional ingredient" is more preferably 5.8 or more, even more preferably 6.0 or more, and even more preferably 8.0 or more.

[0044] In condition (iii-a), when the LogP of the poorly water-soluble functional ingredient is 4.2 or more, the lower limit of the value of "weight of oil / weight of poorly water-soluble functional ingredient" is more preferably [-0.38 × (LogP of poorly water-soluble functional ingredient) + 5.9] or more, and even more preferably [-0.38 × (LogP of poorly water-soluble functional ingredient) + 6.7] or more. When condition (iii) is satisfied, the amount of oil required to stably dissolve the poorly water-soluble functional ingredient is sufficient, and a microemulsion with excellent stability can be realized.

[0045] Here, LogP is the common logarithm of the 1-octanol / water (or buffer) partition coefficient of a chemical substance. In this specification, LogP refers to a value measured by the shake flask method according to the OECD GUIDELINE FOR THE TESTING OF CHEMICALS, "Partition Coefficient (n-octanol / water): Shake Flask Method." The larger the LogP value of a compound, the higher its lipophilicity. In other words, the larger the LogP value of a compound, the higher its lipophilicity.

[0046] When preparing the nanoemulsion of Combination 1, the description in International Publication No. 2021 / 005676 can be referred to as appropriate.

[0047] (Combination 2) In Combination 2, each component constituting the nanoemulsion satisfies the following conditions. The poorly water-soluble functional ingredient includes a glycerin ester-based oil (such as PCA glyceryl oleate). In one embodiment, no poorly water-soluble functional ingredient other than the glycerin ester-based oil is included. The surfactants include polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil. In one embodiment, no surfactants other than polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil are included. The oil comprises medium chain triglycerides. In one embodiment, no oil other than medium chain triglycerides is included.

[0048] In combination 2, it is more preferable that each component satisfies the following conditions (ib) and (ii-b), and even more preferable that each component satisfies conditions (ib), (ii-b), and (iii-b). If a nanoemulsion is prepared with such a composition, the average particle size can be reduced, the particle size distribution can be narrowed, and the particle size uniformity can be improved. (ib) The value of "total weight of polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil / weight of oil" is 6.50 to 240. (ii-b) The value of "total weight of polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil / weight of oil and poorly water-soluble functional ingredient" is 6.50 to 200. (iii-b) The value of "weight of oil / weight of poorly water-soluble functional ingredient" is 2.30 to 2000.

[0049] In condition (ib), the lower limit of the value of "total weight of polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil / weight of oil" is more preferably 7.5 or more, even more preferably 8.5 or more, even more preferably 9.0 or more, and particularly preferably 9.6 or more.

[0050] In condition (ii-b), the lower limit of the value of "total weight of polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil / weight of oil and poorly water-soluble functional ingredient" is more preferably 6.6 or more, even more preferably 6.7 or more, and even more preferably 6.8 or more.

[0051] In the condition (iii-b), the lower limit of the value of "weight of oil / weight of poorly water-soluble functional ingredient" is more preferably 2.35 or more, and even more preferably 2.45 or more. When the condition (iii) is satisfied, the amount of oil required to stably dissolve the poorly water-soluble functional ingredient becomes sufficient, and a microemulsion with excellent stability can be realized.

[0052] [1.2. Nanoemulsion manufacturing method] The nanoemulsion can be obtained, for example, by the following procedure. 1. A poorly water-soluble functional ingredient, a surfactant, and an oil are mixed to obtain a composition. 2. The obtained composition is mixed with an aqueous medium to obtain a nanoemulsion.

[0053] In step 1, the order in which the surfactant, oil, and poorly water-soluble functional component are mixed is not particularly limited. All components may be mixed simultaneously. The surfactant and oil may be mixed, and then the poorly water-soluble functional component may be mixed. The surfactant and the poorly water-soluble functional component may be mixed, and then the oil may be mixed. The oil and the poorly water-soluble functional component may be mixed, and then the surfactant may be mixed.

[0054] In step 1, the method for mixing the components is not particularly limited as long as it can uniformly dissolve the surfactant, oil, and poorly water-soluble functional component. For example, the components can be mixed and stirred. This method allows the components to be stirred uniformly without applying particularly strong shearing force. For example, a magnetic stirrer can be used for stirring.

[0055] There are no particular limitations on the temperature at which the components are mixed in step 1. The temperature is preferably 20 to 90°C or lower, and more preferably 30 to 75°C.

[0056] In step 2, the method for mixing the composition and the aqueous medium is not particularly limited as long as the composition can be dispersed in the aqueous medium as emulsified particles. For example, a method of mixing the composition and the aqueous medium and stirring them can be used. For stirring, for example, a magnetic stirrer can be used. In step 2, the aqueous medium may be added all at once, or may be added in several portions with stirring.

[0057] There are no particular limitations on the temperature at which the composition and the aqueous medium are mixed in step 2. The temperature is preferably 20 to 90°C, and more preferably 30 to 75°C.

[0058] [2. Skin Care Products] A skin care product according to one embodiment of the present invention contains a skin care agent according to one embodiment of the present invention. The term "skin care product" refers to a product that provides various effects to the skin. Skin care products may be classified as pharmaceuticals, quasi-drugs, cosmetics, or miscellaneous goods under Japanese regulatory classifications. Examples of dosage forms of skin care products include creams, emulsions, skin lotions, lotions, ointments, gels, and body powders.

[0059] When the skin care product is a cream, it is preferable that the main component is water and that the cream contains polyglyceryl-3 methylglucose distearate and glyceryl stearate. In this embodiment, the preferred content of each component is as follows, with the total mass of the cream being 100% by mass: Poorly water-soluble functional component: preferably 3.0% by mass or less, more preferably 1.0% by mass or less. Polyglyceryl-3 methylglucose distearate: preferably 10% by mass or less, more preferably 5.0% by mass or less. Glyceryl stearate: preferably 10% by mass or less, more preferably 5.0% by mass or less. Water: preferably 30% by mass or more, more preferably 60% by mass or more.

[0060] When the skin care product is a milky lotion, it preferably contains water as the main ingredient and isopropyl palmitate. In this embodiment, the preferred content of each ingredient is as follows, with the total mass of the milky lotion being 100% by mass: Poorly water-soluble functional ingredients: preferably 3.0% by mass or more, more preferably 1.0% by mass or more Isopropyl palmitate: preferably 10% by mass or less, more preferably 5.0% by mass or less. Water: preferably 30% by mass or more, more preferably 60% by mass or more.

[0061] When the skin care product is a lotion, it preferably contains water as the main ingredient and 1,3-butylene glycol. In this embodiment, the preferred content of each ingredient is as follows, with the mass of the total lotion being 100% by mass: Poorly water-soluble functional component: preferably 3.0% by mass or more, more preferably 1.0% by mass or more. 1,3-butylene glycol: preferably 30% by mass or less, more preferably 20% by mass or less. Water: preferably 50% by mass or more, more preferably 70% by mass or more.

[0062] In each of the above embodiments, if the content of each component is within the above range, the moisturizing effect is improved. In these embodiments, the poorly water-soluble functional component is preferably one or more selected from sphingolipids (such as ceramides), glycerin ester-based oils (such as PCA glyceryl oleate), fibrous proteins, and coenzyme Q10.

[0063] In addition to the nanoemulsion, the skin care product may contain ingredients and / or additives typically found in skin care products, such as moisturizers, oils and fats, lanolin, higher alcohols, fluorine compounds, silicones, cationic polymers, surfactants (cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants), thickeners and gelling agents, preservatives, chelating agents, pH adjusters, acids and alkalis, solvents, anti-inflammatory agents, fragrances, colorants, antioxidants, UV absorbers, and pearlescent agents.

[0064] Examples of moisturizers include polyhydric alcohols (1,3-butylene glycol, propylene glycol, polyethylene glycol, pentylene glycol, glycerin, sorbitol, etc.), proteins and peptides (gelatin, collagen hydrolyzed peptides, elastin hydrolyzed peptides, keratin hydrolyzed peptides, silk hydrolyzed peptides, soybean hydrolyzed peptides, wheat hydrolyzed peptides, casein hydrolyzed peptides, etc.) and their derivatives, amino acids (arginine, serine, glycine, glutamic acid, trimethylglycine, etc.), plant extracts (aloe extract, witch hazel water, loofah water, chamomile extract, licorice extract, etc.), citrate, chondroitin sulfate, sodium lactate, and sodium 2-pyrrolidone-5-carboxylate.

[0065] Examples of oils and fats include vegetable oils (castor oil, coconut oil, palm oil, palm kernel oil, safflower oil, olive oil, avocado oil, sesame oil, evening primrose oil, wheat germ oil, macadamia nut oil, hazelnut oil, rosehip oil, meadowfoam oil, tea tree oil, peppermint oil, corn oil, rapeseed oil, sunflower oil, cottonseed oil, soybean oil, peanut oil, rice bran oil, liquid shea butter, jojoba oil, etc.), hydrocarbons (liquid paraffin, squalane, light liquid isoparaffin, ceresin, paraffin wax, polyethylene, microcrystalline wax, petrolatum, etc.), fatty acids (lauric acid, myristic acid, palmitic acid, etc.), acetic acid, stearic acid, isostearic acid, etc.), silicone oils (dimethicone, caprylyl methicone, phenyl trimethicone, diphenyl dimethicone, diphenylsiloxyphenyl trimethicone, etc.), esters (di-2-ethylhexyl succinate, isopropyl palmitate, octyldodecyl myristate, cetyl ethylhexanoate, dimer dilinoleate (phytosteryl / isostearyl / cetyl / stearyl / behenyl), etc.), waxes (beeswax, candelilla wax, carnauba wax, rice wax, spermaceti, shellac, cotton wax, Japan wax, hydrogenated jojoba oil, etc.).

[0066] Examples of lanolins include liquid lanolin, reduced lanolin, and adsorbed purified lanolin.

[0067] Examples of higher alcohols include straight-chain alcohols (lauryl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, cetostearyl alcohol, arachyl alcohol, behenyl alcohol, etc.), branched-chain alcohols (monostearyl glycerin ether (batyl alcohol), 2-decyltetradecinol, lanolin alcohol, cholesterol, phytosterol, hexyldodecanol, isostearyl alcohol, octyldodecanol, etc.), and fatty alcohols (hydrogenated rapeseed oil alcohol, etc.).

[0068] Examples of the fluorine-based compounds include fluorine-based compounds and derivatives thereof (such as polyperfluoroethoxymethoxydifluorohydroxyethyl, polyperfluoroethoxymethoxydifluoromethyldistearylamide, and polyperfluoroethoxymethoxydifluoroethylpolyethylene glycol phosphate).

[0069] Examples of silicones include low-viscosity dimethylpolysiloxane, high-viscosity dimethylpolysiloxane, cyclic dimethylsiloxane (decamethylcyclopentasiloxane), methylphenylpolysiloxane, diphenylpolysiloxane, silicone resin, silicone rubber, amino-modified polysiloxane, cation-modified polysiloxane, polyether-modified polysiloxane, and fluorine-modified polysiloxane.

[0070] Examples of cationic polymers include cationic cellulose derivatives, cationic starch, cationic guar gum, diallyl quaternary ammonium polymers or copolymers, and quaternized polyvinylpyrrolidone derivatives.

[0071] Examples of cationic surfactants include cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, alkyltrimethylammonium chloride, distearyldimethylammonium chloride, and lanolin fatty acid aminopropylethyldimethylammonium ethyl sulfate.

[0072] Examples of anionic surfactants include fatty acid salts, alkyl sulfate ester salts, polyoxyethylene alkyl sulfate salts, polyoxyethylene fatty amine sulfate salts, acyl N-methyl taurine salts, alkyl ether phosphate ester salts, and N-acyl amino acid salts.

[0073] Examples of nonionic surfactants include polyhydric alcohol fatty acid partial esters, polyglycerin fatty acid esters, glycerin fatty acid esters (glyceryl myristate, glyceryl stearate, glyceryl behenate, glyceryl distearate, etc.), polyoxyethylene castor oil (PEG20-hydrogenated castor oil, PEG30-hydrogenated castor oil, PEG-35 castor oil, PEG40-hydrogenated castor oil, PEG50-hydrogenated castor oil, PEG-60 castor oil), alkyldimethylamine oxide, alkyl polyglycoside, and alkyl glucoside.

[0074] Examples of amphoteric surfactants include alkyldimethylaminoacetic acid betaine, alkylamidodimethylaminoacetic acid betaine, and 2-alkyl-N-carboxy-N-hydroxyimidazolinium betaine.

[0075] Examples of thickening and gelling agents include cetostearyl glucoside, guar gum, xanthan gum, carrageenan, alginic acid, tragacanth gum, starch derivatives, sodium carboxymethylcellulose, carboxyvinyl polymer, carbomer, meadowfoam oil fatty acid dimethicone copolyol, acrylic acid-methacrylic acid ester copolymer, N,N-dimethylaminoethyl methacrylate diethyl sulfate, N,N-dimethylacrylamide dimethacrylate, acrylic acid-alkyl methacrylate copolymer, polyvinyl alcohol, acrylic resin alkanolamine liquid, (sodium acrylate / sodium acryloyldimethyltaurate) copolymer, (hydroxyethyl acrylate / sodium acryloyldimethyltaurate) copolymer.

[0076] Examples of preservatives include p-hydroxybenzoic acid esters, phenoxyethanol, glycerin, polyhydric alcohols such as 1,3-butylene glycol, propylene glycol, and 1,8 octanediol, and quaternary ammonium salts.

[0077] Examples of chelating agents include edetate, phosphonic acids, and polyamino acids.

[0078] Examples of pH adjusters, acids, and alkalis include phosphoric acid, malic acid, tartaric acid, carbonic acid, fumaric acid, citric acid, lactic acid, glycolic acid, succinic acid, hydrochloric acid, sulfuric acid, nitric acid, hydroxyethanediphosphonic acid and their salts, sodium hydroxide, potassium hydroxide, disodium hydrogen phosphate, monoethanolamine, diethanolamine, triethanolamine, arginine, ammonia water, aminomethylpropanol, and their salts.

[0079] Examples of solvents include water, ethanol, decamethylcyclopentasiloxane, and lower alcohols (such as 2-propanol).

[0080] Examples of anti-inflammatory agents include licorice derivatives (glycyrrhizinic acid, glycyrrhizinic acid 2K, carbenoxolone disodium, etc.), allantoin, guaiazulene, aloe, and α-bisabolol.

[0081] Examples of antioxidants include sodium ascorbate, sodium sulfite, and tocopherol.

[0082] Examples of the ultraviolet inhibitor include ethylhexyl methoxycinnamate, t-butyl methoxydibenzoylmethane, oxybenzone, bisethylhexyloxyphenol methoxyphenyl triazine, and the like.

[0083] Examples of pearlescent agents include titanium oxide, tin oxide, mica, and bismuth chloride.

[0084] Skin care products can be prepared using the above ingredients in a conventional manner.

[0085] The skin care product according to one embodiment of the present invention may be applied to any area, including the face (forehead, eyes, corners of the eyes, cheeks, mouth, etc.), arms, elbows, backs of the hands, fingertips, feet, knees, heels, neck, armpits, and back.

[0086] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Example]

[0087] [Manufacturing example] Nanoemulsions containing ceramide or PCA glyceryl oleate as a poorly water-soluble functional ingredient were prepared according to the compositions shown in Table 1. The specific procedures are as follows. 1. A poorly water-soluble functional ingredient, oil, and surfactant were placed in a 10 mL beaker. The mixture was stirred at 2.60°C using a magnetic stirrer until the poorly water-soluble functional ingredients were all uniformly dissolved, resulting in a viscous liquid. 3. Ion-exchanged water was added to the composition obtained in step 2, and the mixture was further stirred at 60°C for 1 to 3 minutes. 4. After visually checking that there were no unevenly dissolved residues or lumps, the mixture was cooled to room temperature in an ice-water bath.

[0088] [Table 1]

[0089] Details of the ingredients used in Table 1 are as follows: Polysorbate 80: Rheodol TW-O120V (Kao Corporation) Polyoxyethylene castor oil: CO-35 (Nikko Chemicals Co., Ltd.) Polyoxyethylene glyceryl isostearate: Brownon RGL-20MISE (manufactured by Aoki Oil Co., Ltd.) Diisostearyl malate: DISM (Nikko Chemicals Co., Ltd.) Medium-chain fatty acid triglyceride: Coconard MT (Kao Corporation) Ceramide: CERAMIDE2 (manufactured by Croda Japan) PCA glyceryl oleate: Amiguri P-30V (manufactured by Taiyo Kagaku Co., Ltd.)

[0090] The average particle size of Nanoemulsion 1 was 12.29 nm, the PDI was 0.136, it contained no particles larger than 100 nm, and there were no subpeaks in the particle size distribution. The average particle size of Nanoemulsion 2 was 13.02 nm, the PDI was 0.019, it contained no particles larger than 100 nm, and there were no subpeaks in the particle size distribution. These measurements were taken using a Zetasizer Nano ZS (Malvern Institutes) in the measurement mode "size-small-vol-cell x 1.SOP."

[0091] Example 1 The effect of applying a skin care agent according to one embodiment of the present invention to a skin cream was investigated. Specifically, a cream containing the skin care agent was continuously applied to the skin of an arm, and the change in the moisture content of the skin was measured.

[0092] [Manufacturing Example 1] A skin cream was prepared according to the following procedure. The ingredients and their contents are shown in Tables 2A and 2B. 1. Phases A and B were dissolved by heating. 2. Phase B was added to Phase A and emulsified using a homomixer. 3. After emulsification was complete, the mixture was cooled to prepare a skin cream base. 4. The skin care agent was added to the base obtained in step 3 and mixed at room temperature.

[0093] [Table 2]

[0094] [Examples 1-1 to 1-2, Comparative Examples 1-1 to 1-3] The moisturizing effect of the prepared cream was examined according to the following procedure. 1. A cream prepared according to the composition shown in Table 2B was applied to the inside of the right forearm of each subject twice a day (0.05 mL per application). Each cream according to the Examples or Comparative Examples was applied to two areas. 2. Eight days after application of the cream, the moisture content of the applied area was measured and compared with the moisture content before application. A moisture checker (manufactured by SCALAR) was used to measure the moisture content. The values ​​shown in Table 3 are the average values ​​measured at two locations.

[0095] In Example 1-1 and Comparative Example 1-2, the total ceramide content in the cream was adjusted to be the same (0.03% by mass). In Example 1-2 and Comparative Example 1-3, the total PCA acid glyceryl oleate content in the cream was adjusted to be the same (0.10% by mass). Note that the ceramide-containing raw material (SK-INFLUX, manufactured by Evonik) that was not nanoemulsified was used in Comparative Example 1-2.

[0096] [Table 3]

[0097] [result] According to Table 3, the skin to which the cream according to Example 1-1 was applied showed a greater improvement in moisture content than the skin to which the cream according to Comparative Example 1-2 was applied. In other words, the moisturizing effect was improved by incorporating ceramide in the form of a nanoemulsion. Similarly, the skin to which the cream according to Example 1-2 was applied showed a greater improvement in moisture content than the skin to which the cream according to Comparative Example 1-3 was applied. In other words, the moisturizing effect was improved by incorporating PCA glyceryl oleate in the form of a nanoemulsion.

[0098] In addition, the moisture content of the skin to which the creams of Comparative Examples 1-2 and 1-3 were applied was unchanged or even decreased compared to the skin to which the cream of Comparative Example 1-1 was applied, suggesting that even if ceramide or PCA glyceryl oleate is blended without being nanoemulsified, no moisturizing effect can be obtained.

[0099] From these results, it can be said that when the skin care agent according to one embodiment of the present invention is applied to a cream, it can provide an excellent moisturizing effect to the skin.

[0100] Example 2 The effect of applying a skin care agent according to one embodiment of the present invention to a lotion was investigated. Specifically, a lotion containing the skin care agent was continuously applied to the skin of the arm, and the change in the moisture content of the skin was measured.

[0101] [Manufacturing Example 2] The emulsion was prepared according to the following procedure. The ingredients used and their contents are shown in Tables 4A and 4B. 1. Phases A and B were dissolved by heating. 2. Phase B was added to Phase A and emulsified using a propeller mixer. 3. After emulsification was complete, the mixture was cooled. 4. Phase C was added and stirred. 5. Phase D was added to prepare an emulsion base. 6. The skin care agent was added to the emulsion prepared in step 5 and stirred at room temperature.

[0102] [Table 4]

[0103] [Examples 2-1 to 2-2, Comparative Examples 2-1 to 2-3] The moisturizing effect of the prepared emulsion was examined according to the following procedure. 1. The emulsion prepared according to the composition shown in Table 4B was applied to the inside of the right forearm of each subject (0.05 mL). Each emulsion according to the Examples or Comparative Examples was applied to two locations. 2. 15 minutes and 30 minutes after application of the lotion, the amount of moisture at the applied area was measured and compared with the amount of moisture before application. A moisture checker (manufactured by SCALAR) was used to measure the amount of moisture. The values ​​shown in Table 5 are the average values ​​measured at two locations.

[0104] In Example 2-1 and Comparative Example 2-2, the total ceramide content in the emulsion was adjusted to be the same (0.03% by mass). In Example 2-2 and Comparative Example 2-3, the total PCA acid glyceryl oleate content in the emulsion was adjusted to be the same (0.10% by mass). Note that the ceramide-containing raw material (SK-INFLUX, manufactured by Evonik) that was not nanoemulsified was used in Comparative Example 2-2.

[0105] [Table 5]

[0106] [result] According to Table 5, the skin to which the emulsion of Example 2-1 was applied had a higher moisture content 30 minutes later than the skin to which the emulsion of Comparative Example 2-2 was applied. In other words, the incorporation of ceramide in nanoemulsion resulted in a longer-lasting moisturizing effect. Similarly, the skin to which the emulsion of Example 2-2 was applied had a higher moisture content 30 minutes later than the skin to which the emulsion of Comparative Example 2-3 was applied. In other words, the incorporation of PCA glyceryl oleate in nanoemulsion resulted in a longer-lasting moisturizing effect.

[0107] When the skin to which the emulsions of Comparative Examples 2-2 and 2-3 were applied was compared with the skin to which the emulsions of Examples 2-1 and 2-2 were applied, the moisture content after 15 minutes was similar, but the moisture content after 30 minutes was lower in the former. This suggests that the moisturizing effect does not last long even if ceramide or PCA glyceryl oleate is blended without being nanoemulsified.

[0108] From these results, it can be said that when the skin care agent according to one embodiment of the present invention is applied to an emulsion, it provides an excellent moisturizing effect to the skin.

[0109] Example 3 The effect of applying a skin care agent according to one embodiment of the present invention to a lotion was investigated. Specifically, a lotion containing the skin care agent was continuously applied to the skin of an arm, and the change in the moisture content of the skin was measured.

[0110] [Manufacturing Example 3] A lotion was prepared according to the following procedure. The ingredients used and their contents are shown in Tables 6A and 6B. 1. Phase A was dissolved by heating and then cooled. 2. The mixed phase B was added to phase A and stirred until uniform. 3. Phase C was added to prepare a base for the lotion. 4. The skin care agent was added to the base prepared in step 3.

[0111] [Table 6]

[0112] [Example 3-1, Comparative Examples 3-1 and 3-2] The moisturizing effect of the prepared lotion was examined according to the following procedure. 1. The lotion prepared with the composition shown in Table 6B was applied to the inside of the right forearm of the subject twice a day (0.03 mL per application). Each lotion according to the Examples or Comparative Examples was applied to two areas. 2. Seven and 14 days after application of the lotion, the moisture content of the applied area was measured and compared with the moisture content before application. A moisture checker (manufactured by SCALAR) was used to measure the moisture content. The values ​​shown in Table 7 are the average values ​​measured at two locations.

[0113] In Example 3-1 and Comparative Example 3-2, the total ceramide content in the lotion was adjusted to be the same (0.03% by mass). Note that the ingredient blended in Comparative Example 3-2 was a non-nanoemulsified ceramide-containing raw material (SK-INFLUX, manufactured by Evonik).

[0114] [Table 7]

[0115] [result] According to Table 7, the skin to which the lotion of Example 3-1 was applied had a higher moisture content after 14 days than the skin to which the lotion of Comparative Example 3-2 was applied. In other words, the moisturizing effect was enhanced by incorporating ceramide in nanoemulsion. Furthermore, Example 3-1 was transparent, while Comparative Example 3-2 was translucent. In other words, it is suggested that incorporating ceramide in nanoemulsion allows for the production of a transparent product with excellent appearance.

[0116] From these results, it can be said that when the skin care agent according to one embodiment of the present invention is applied to a lotion, it provides an excellent moisturizing effect to the skin and also provides an excellent appearance. [Industrial Applicability]

[0117] The present invention can be used in skin care products and the like.

Claims

1. A skin care agent, The nanoemulsion contains a monodisperse nanoemulsion having an average particle size of 18 nm or less, a particle size distribution index (PDI) of 0.14 or less, and no particles of 100 nm or more, The nanoemulsion is a skin care agent containing a poorly water-soluble functional ingredient having a moisturizing effect, a surfactant, an oil, and an aqueous medium.

2. A skin care agent, The nanoemulsion contains a monodisperse nanoemulsion having an average particle size of 18 nm or less, a particle size distribution index (PDI) of 0.14 or less, and no particles of 100 nm or more, The nanoemulsion contains a poorly water-soluble functional ingredient, a surfactant, an oil, and an aqueous medium; The skin care agent, wherein the poorly water-soluble functional ingredient comprises at least one selected from sphingolipids and glycerin ester-based oils.

3. The poorly water-soluble functional ingredient contains a sphingolipid, The surfactant includes polysorbate 80 and polyoxyethylene castor oil, The oil contains diisostearyl malate. The skin care agent according to claim 1 or 2.

4. The poorly water-soluble functional ingredient contains a glycerin ester-based oil agent, The surfactant includes polyoxyethylene glyceryl isostearate and polyoxyethylene castor oil, The oil contains medium-chain triglycerides. The skin care agent according to claim 1 or 2.

5. A skin care product comprising the skin care agent according to any one of claims 1 to 4.

6. 6. The skin care product according to claim 5, which is a cream, emulsion, or lotion.

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