Oil gel particles and topical skin composition containing the same

Abstract

To provide oil gel particles or the like that have highly transparent external appearance, where oil solution has characteristic moist touch when applied onto skin.SOLUTION: Oil gel particles contain 50 to 99 mass% of oil solution and 0.5 to 50 mass% of gelatinizer, where an IOB value of the oil solution is 0.85 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to oil gel particles that contain an oil agent and have a transparent appearance, and to a composition for external use on the skin containing the same. [Background technology]

[0002] Oily particles, microcapsules, and the like that are large enough to be visible to the naked eye and can be incorporated into externally applied compositions such as cosmetics are known.

[0003] For example, Patent Document 1 describes oily particles containing a dextrin fatty acid ester and a liquid oil, which are obtained by adding 5 to 40% by mass of the dextrin fatty acid ester to the total mass of the oily particles, and which have an average particle size of 0.05 to 10 mm. Patent Document 2 also describes oily particles produced by adding 5 to 40% by mass of an amphiphilic substance containing batyl alcohol and / or glyceryl stearate and having a melting point of 45 to 75°C to the total mass of the oily particles, and discloses that the stability of the vitamin A fatty acid ester contained in the oily particles is improved. Patent Document 3 also describes a method for producing such oily particles, in which a liquid oil maintained at a temperature above its melting point is added to an aqueous solvent being stirred at a temperature of 55 to 75°C, where the specific gravity of the oil relative to the aqueous solvent is 0.90 to 2.3, and the aqueous solvent is then cooled to a temperature below the melting point of the oil while stirring, thereby granulating oily particles of the oil in the aqueous solvent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-36001 [Patent Document 2] Patent No. 4330511 [Patent Document 3] Patent No. 4189921 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the oily particles described in Patent Document 1 are intended to be granulated within a cosmetic formulation, and if one attempts to sift the granulated oily particles alone for use in other applications, the particles will be crushed on the sieve, making it unlikely that the particles will be obtained alone. The oily particles described in Patent Document 2 contain a high concentration of batyl alcohol and / or glyceryl stearate, which have high water affinity and crystallinity, as a coating for the oily particles, and the appearance of the particles is thought to become cloudy due to emulsification during granulation and crystal precipitation after cooling. The oily particles described in Patent Document 3, like those described in Patent Document 2, also contain a high concentration of behenyl alcohol, which has high water affinity and crystallinity, as a particle solidifying component, and are thought to become cloudy in appearance.

[0006] On the other hand, if the amount of gelling agent or solid oil is excessively increased in order to sieve the oily particles, the particles will be too hard and will feel bad when applied to the skin. Also, if an emulsifier or a component with high affinity for water is added to the particles, it is thought that there is an advantage in that the particles will blend with water and be easily crushed when the particles are added to water-based cosmetics such as lotions.

[0007] Therefore, the present invention aims to solve the problem of providing oil gel particles that have a highly transparent appearance in the atmosphere, are strong enough to be able to use a sieve, and have a moist feel that is characteristic of oily agents when applied to the skin, as well as cosmetics containing the oil gel particles. [Means for solving the problem]

[0008] The present invention has been made to solve the above-mentioned problems, and provides, for example, oil gel particles in which the types and contents of the oil agent and gelling agent used in the oil gel particles are optimized, and the balance between the organic value and inorganic value of the oil agent is adjusted.

[0009] That is, the present invention includes the following embodiments. [1] Oil gel particles containing 50 to 99% by mass of an oil agent and 0.5 to 50% by mass of a gelling agent, wherein the IOB value of the oil agent is 0.85 or less. [2] The oil gel particles according to [1], further comprising 0.5 to 10 mass % of a surfactant, wherein the combined HLB value of the oil agent and the surfactant is 8.5 or less. [3] The oil gel particles according to [1] or [2], having an average particle size of 100 to 2000 μm. [4] Oil gel particles according to any one of [1] to [3], wherein the oil agent is at least one selected from the group consisting of hydrocarbon oils, ester oils, silicone oils, and vegetable oils. [5] Oil gel particles according to any one of [1] to [4], wherein the gelling agent is a dextrin fatty acid ester, an inulin fatty acid ester, and / or an amino acid-based oil gelling agent. [6] A composition for external use on skin, comprising the oil gel particles according to any one of [1] to [5] in a dispersed state in an aqueous medium or an oily medium. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide oil gel particles and the like which have a highly transparent appearance and, when applied to the skin, have a moist feel characteristic of oily agents. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows an outline of the evaluation of dispersibility (absorbance test) described in Examples 35 to 40. DETAILED DESCRIPTION OF THE INVENTION

[0012] Next, various embodiments of the present invention will be described. Note that the various embodiments described below do not limit the scope of the invention as claimed, and not all of the elements and combinations thereof described in the various embodiments are necessarily essential to the solution of the present invention.

[0013] (oil gel particles) An oil gel particle according to one embodiment of the present invention comprises (A) 50 to 99% by mass of an oil agent and (B) 0.5 to 50% by mass of a gelling agent. Here, "oil gel particle" refers to one or more particles in which a desired component is dissolved or dispersed in an oil agent. Furthermore, in this specification, "oil gel" refers to a gel-like oil agent (oil-based component) thickened with a lipophilic gelling agent, and can be prepared, for example, by adding an oily gelling agent to an oil agent.

[0014] The shape of the oil gel particles is not particularly limited, but is preferably spherical from the viewpoints of shape stability and aesthetics. Here, "spherical" refers not only to a perfect sphere but also to an elliptical cross section, with a perfect sphere being preferred. Furthermore, the average particle size of the oil gel particles of this embodiment is preferably 100 μm or more, more preferably 125 μm or more, even more preferably 150 μm or more, and even more preferably 175 μm or more, for example, to facilitate the production of spherical particles or to allow for visual observation of the particles when producing the particles. Furthermore, the upper limit of the average particle size is 2000 μm or less, preferably 1500 μm or less, and more preferably 1000 μm or less, to prevent the particles from becoming too hard. The average particle size of the oil gel particles can be measured by laser diffraction / scattering or sieving. The laser diffraction / scattering method involves measuring the median diameter using a particle size distribution analyzer (e.g., Horiba, Ltd., Model No. LA-920) and using this as the average particle size. The sieve method involves wet classifying 100 g of oil gel particles in water using sieves with various mesh sizes, removing excess water with filter paper, measuring the mass, and using the weight-average particle size as the average particle size.

[0015] Furthermore, from the viewpoint of improving the feel during use, the compression breaking strength of the oil gel particles of this embodiment is preferably 50 kPa or less. From the viewpoint of maintaining the shape of the oil gel particles and facilitating their incorporation into topical skin preparations, cosmetics, etc., the compression breaking strength of the oil gel particles of this embodiment is preferably 0.15 kPa or more, more preferably 0.20 kPa or more, and even more preferably 0.25 kPa or more. Furthermore, from the viewpoint of achieving good spreadability and compatibility on the skin when applied to the skin and enabling smoother disintegration, the compression breaking strength of the oil gel particles of this embodiment is more preferably 40 kPa or less, and even more preferably 30 kPa or less.

[0016] The compressive breaking strength here refers to the maximum stress at which a gel sample breaks when a compressive load is applied to the gel sample. The compressive breaking strength is calculated by dividing the compressive force when a uniaxial load is applied to a spherical gel sample by the cross-sectional area perpendicular to the axis (kPa (N / m 2 )). Compressive breaking strength is also called compressive breaking stress, and can be measured by a known method using a known measuring device. An example of a compressive breaking strength measuring device is a compression tester (Rheo Meter: CR-3000EX) manufactured by Sun Scientific Co., Ltd. The compressive breaking strength specified in this embodiment is a value measured by the measuring method described in the examples below.

[0017] The oil gel particles of the present embodiment can contain desired components and may contain optional components as long as the effects of the present invention are not impaired. The components blended in the oil gel particles of the present embodiment and their contents will be described in detail below.

[0018] (oil) The oil agent of component (A) used in the oil gel particles of this embodiment can be a liquid oil used in external compositions such as cosmetics. Specific examples include liquid oils derived from animals and plants, such as linseed oil, camellia oil, macadamia nut oil, corn oil, olive oil, avocado oil, camellia oil, castor oil, safflower oil, apricot kernel oil, cinnamon oil, jojoba oil, grape oil, sunflower oil, almond oil, rapeseed oil, sesame oil, wheat germ oil, rice germ oil, rice bran oil, cottonseed oil, soybean oil, peanut oil, tea seed oil, evening primrose oil, egg yolk oil, and cod liver oil. These liquid oils can be synthetic or commercially available. Commercially available products include, for example, DHA-55 (manufactured by Maruha Nichiro Co., Ltd.), safflower oil (manufactured by Nisshin Oillio Co., Ltd.), Oryza salad oil (manufactured by Oryza Oil & Fat Chemical Co., Ltd.), edible olive oil (manufactured by J-Oil Mills Co., Ltd.), linseed oil S (manufactured by Nippon Flour Mills Co., Ltd.), and Coconard ML (manufactured by Kao Corporation).

[0019] Furthermore, ester oils such as octanoic acid esters such as cetyl octanoate, isooctanoic acid esters such as glycerin tri-2-ethylhexaenoate and pentaerythritol tetra-2-ethylhexanoate, lauric acid esters such as hexyl laurate, myristates such as isopropyl myristate and octyldodecyl myristate, palmitic acid esters such as octyl palmitate, stearic acid esters such as isocetyl stearate, isostearic acid esters such as isopropyl isostearate, isopalmitic acid esters such as octyl isopalmitate, oleic acid esters such as isodecyl oleate, adipic acid diesters such as diisopropyl adipate, sebacate diesters such as diethyl sebacate, and diisostearyl malate can be used.

[0020] Further examples include silicone oils, for example, chain silicones such as dimethylpolysiloxane, methylphenylpolysiloxane, and methylhydrogenpolysiloxane; cyclic silicones such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane; amino-modified silicone oils, polyether-modified silicone oils, carboxy-modified silicone oils, alkyl-modified silicone oils, ammonium salt-modified silicone oils, and fluorine-modified silicone oils.

[0021] Further examples include hydrocarbon oils such as liquid paraffin, squalane, squalene, pristane, isoparaffin, α-olefin oligomers, and petrolatum.

[0022] Further examples include higher alcohols such as octyldodecanol, hexyldecanol, isostearyl alcohol, oleyl alcohol, cetanol, and behenyl alcohol.

[0023] Further examples include fatty acids such as oleic acid, linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid, arachidonic acid, lauric acid, myristic acid, palmitic acid, and stearic acid.

[0024] These oils may be solid or liquid at room temperature, but a composition with a high proportion of liquid oils is preferred from the viewpoints of imparting softness to the oil gel particles, transparency of the appearance, adjustment of the IOB value, etc., and one or more types can be combined and contained in the oil gel particles depending on the specific purpose. For example, by using isononyl isononanoate, octyldodecanol, etc. among these oils, it is possible to impart softness when crushed on the skin, a transparent appearance, and a moist feeling to the oil gel particles.

[0025] Furthermore, by using silicone oil as the oil agent, it is possible to impart a moist and smooth feeling to the skin in addition to the good compatibility with the oil gel particles.

[0026] Furthermore, by using hydrocarbon oil as the oil agent, it is possible to impart a moist feeling to the skin in addition to the good skin-compatibility of the oil gel particles.

[0027] The content of the oil agent in the oil gel particles of this embodiment is 50% by mass or more, preferably 55% by mass or more, and more preferably 60% by mass or more, based on the total amount of the oil gel particles, from the viewpoint of dissolving the oily gelling agent. In addition, in order to add and solidify the gelling agent, the content is 99% by mass or less, preferably 98.5% by mass or less, and more preferably 98.1% by mass or less.

[0028] To obtain transparent oil gel particles, an oil with a refractive index close to that of water (1.333) must be used, and the oil must have a specific balance of organic and inorganic properties. Regarding the physicochemical properties of the individual compounds contained in the oil, properties primarily due to van der Waals forces are called "organic," while properties primarily due to electrical affinity are called "inorganic." The properties of the compound can be characterized by their combination. Each compound is assigned a unique characteristic value—organic value (OV) or inorganic value (IV)—to determine the organic and inorganic values ​​of each compound. By comparing and adjusting the organic and inorganic values ​​of each compound, the appropriate oil for transparent oil gel particles can be selected.

[0029] For example, the upper limit of the IOB value of the oil agent is preferably 0.85 or less, more preferably 0.84 or less, and even more preferably 0.83. Here, the IOB value represents the ratio of inorganic and organic values ​​(Inorganic Organic Balance) calculated based on the Organic Conceptual Diagram (Fujita Atsushi, Prediction of Organic Compounds and Organic Conceptual Diagrams, Chemistry Vol. 11, No. 10 (1957) 719-725), and is calculated by dividing the inorganic value by the organic value. When two or more oil agents are contained, the IOB value after mixing can be calculated as a weighted average. An IOB value of 0.85 or less can achieve the moist feel characteristic of oil gels. The IOB value may be 0, as in the case of squalane, a hydrocarbon oil, but is preferably greater than 0, more preferably 0.01 or greater, and even more preferably 0.015.

[0030] (gelling agent) The gelling agent of component (B) used in the oil gel particles of the present invention is a component that gels the oil in a transparent to translucent state, has the effect of imparting viscosity over a wide range, and improves stability over time and the feel when applied to the skin. Its content is 0.5% by mass or more, preferably 1% by mass or more, and more preferably 1.5% by mass or more, so that the particles solidify. Furthermore, to prevent the particles from becoming too hard, its content is 50% by mass or less, preferably 45% by mass or less, and more preferably 40% by mass or less. Examples of preferred gelling agents used in this embodiment include dextrin fatty acid esters, inulin fatty acid esters, and / or amino acid-based oil gelling agents.

[0031] Dextrin fatty acid esters are esters of dextrin with a fatty acid or a fatty acid derivative, preferably an ester of a higher fatty acid having 8 to 22 carbon atoms. The average glycopolymerization degree of the dextrin is preferably 3 to 150, and the degree of fatty acid substitution per glucose unit of the dextrin is preferably 1.5 to 1.7. Specific examples include dextrin octanoate, dextrin laurate, dextrin palmitate, dextrin myristate, dextrin stearate, dextrin behenate, coconut oil fatty acid dextrin, and (palmitate / octanoate) dextrin. Commercially available products of these dextrin fatty acid esters include "Leopearl KL2," "Leopearl MKL2," "Leopearl TT2," and "Leopearl TL2" (all manufactured by Chiba Flour Milling Co., Ltd.). Among these, dextrin palmitate is most preferred in terms of stability over time and ease of use.

[0032] Inulin fatty acid esters are esters of inulin with a fatty acid or a fatty acid derivative, and preferably esters of inulin with a linear or branched saturated or unsaturated fatty acid having 8 to 32 carbon atoms, with the average molecular weight of the inulin preferably being in the range of 300 to 10,000. Specific examples include those described in JP-A-3-197409 and JP-A-2002-193732, and commercially available products include "Leopearl ISK2" (manufactured by Chiba Flour Milling Co., Ltd.).

[0033] The blending amount of the dextrin fatty acid ester and / or inulin fatty acid ester used in this embodiment is preferably 1 to 50% by mass, since stability over time and spreadability are superior, and is preferably 3 to 45% by mass, since spreadability is even superior.

[0034] There are various amino acid-based oil gelling agents that can be used in the present embodiment, and among the amino acid derivatives, N-acylamino acid esters and N-acylamino acid amides can be obtained, for example, by reacting N-acylamino acids with alcohols or amines by heating in the presence or absence of an acid catalyst, respectively, or by N-acylation of amino acid esters or amino acid amides with an acylating agent such as a fatty acid halide. Also, N-acylamino acid amine salts can be easily obtained by neutralizing N-acylamino acids with amines. Examples of these compounds include N-lauroylglutamic acid dilaurylamide, N-caproylglutamic acid dilaurylamide, N-lauroylglutamic acid dibutylamide, N-lauroylglutamic acid stearylamide, Nα·Nω-dicaproyl lysine lauryl ester, Nα·Nω-distearoyl lysine octyl ester, N-stearoylglycine laurylamide, N-palmitoyl-ε-aminocaproic acid lauryl ester, Nα-Nω-dicapryloyl lysine stearylamine, N-lauroylvaline laurylamine salt, N-lauroylglutamic acid dioctylamide, and Nα·Nω-dilauroyl lysine stearylamine salt. The amount of amino acid oil gelling agent used in this embodiment is suitably 0.5 to 10.0%. If the amount is less than 0.5%, the gelling ability is significantly reduced, and even if the amount is increased beyond 10.0%, no significant effect can be expected.

[0035] (surfactant) The oil gel particles of the present embodiment may contain a surfactant from the viewpoint of improving the feel upon application and the solubility of added ingredients when the particles are incorporated into aqueous cosmetics, etc. The surfactant may be one or a mixture of two or more selected from nonionic surfactants, zwitterionic surfactants, etc.

[0036] Examples of nonionic surfactants include fatty acid sorbitan esters, polyoxyethylene fatty acid sorbitan, polyoxyethylene higher alcohol ethers, poly(oxyethylene-oxypropylene) higher alcohol ethers, polyoxyethylene fatty acid esters, polyoxyethylene alkylphenols, polyoxyethylene alkylamines, polyoxyethylene-polyoxypropylene block polymers, etc. Examples of amphoteric surfactants include dimethyl alkyl betaines, alkylamido betaines, etc.

[0037] When a surfactant is used, the amount of surfactant added is 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.2% by mass or more, relative to the total amount of oil gel particles. If the amount is less than 0.05% by mass, the effect of adding the surfactant is insufficient. The upper limit of the amount of surfactant added is 10% by mass or less, preferably 8% by mass or less, and more preferably 6% by mass or less, relative to the total amount of oil gel particles. If the amount exceeds 10% by mass, emulsification may occur during granulation, which may impair the transparency of the oil gel, and this is not preferred.

[0038] In the oil gel particles of this embodiment, the combined HLB value of the oil agent and surfactant is preferably 8.5 or less. The oil agent and surfactant may be a mixture of two or more types. Here, the HLB value refers to the HLB value at 25°C as defined by Griffin, which represents the degree of hydrophilicity or lipophilicity (hydrophobicity) of a surfactant. The Griffin HLB value is defined in J. Soc. Cosm. Chem., 1954, 5:249-256. Furthermore, the concepts of organic and inorganic values ​​of oil agents in the organic conceptual diagram are highly correlated with the concepts of hydrophilicity and lipophilicity in the HLB method. When the value calculated from the ratio of organic value to inorganic value (IV / OV = IOB (Inorganic Organic Balance)) is compared with the HLB value, the approximate formula HLB value = IOB value × 10 holds.

[0039] Therefore, in this specification, the mixed HLB value refers to the HLB value of a mixture of one or more oil agents and one or more surfactants when these are used, and is the weighted average of the HLB values ​​of the individual oil agents and surfactants based on their content mass ratio, and is calculated by the following formula:

[0040] Mixed HLB Value =Σ(10×IOBx×Wx) / ΣWx+Σ(HLBy×Wy) / ΣWy (IOBx represents the IOB value of oil agent X, Wx represents the mass (g) of oil agent X, HLBy represents the HLB value of surfactant Y, and Wy represents the mass (g) of surfactant Y.)

[0041] This mixed HLB value may be 0, but from the viewpoint of making the oil gel particles more compatible with water when used in aqueous cosmetic formulations, it is more preferable that the mixed HLB value exceeds 0, more preferably 0.1 or more, and even more preferably 0.15 or more. Furthermore, in order to enable particle formation without emulsification, the HLB value is preferably 8.5 or less, more preferably 8.4 or less, and even more preferably 8.3 or less.

[0042] (Manufacturing method) The method for producing oil gel particles of this embodiment is preferably carried out as follows. First, the oil agent and gelling agent are mixed and adjusted to a temperature above the melting point of the oily component (usually a temperature above the melting point of the gelling agent) to form a liquid. This mixture is then introduced under stirring into an aqueous solvent adjusted to a temperature low enough to prevent emulsification but high enough to disperse the oily component by stirring (15 to 75°C, with 30 to 60°C being particularly preferred). The mixture of aqueous solvent and oily component is then further cooled under stirring (preferably to room temperature) to form oil gel particles in the aqueous solvent. Examples of aqueous solvents that can be used include water, ethanol, glycerin, butylene glycol, and dipropylene glycol, which may be used alone or in suitable combinations. Thickeners, surfactants, and the like may also be added.

[0043] As mentioned above, the main determining factors for the size of oily particles are the stirring speed of the aqueous solvent and the temperature of the aqueous solvent when the oily component is introduced. The stirring speed of the aqueous solvent is relatively slow, specifically, 10 to 1500 rpm, preferably about 20 to 300 rpm, and can be performed using a propeller, paddle mixer, or the like. The higher the rotation speed, the smaller the particle diameter of the oily particles tends to be, while the lower the rotation speed, the larger the particle diameter of the oily particles tends to be. Furthermore, as mentioned above, the temperature of the aqueous solvent when the oily component is added is preferably 15 to 75°C, and about 30 to 60°C is particularly preferred. That is, if the oily component is added to an aqueous solvent at a temperature lower than 15°C, it will solidify before forming spherical particles, tending to produce large, irregular particles. Furthermore, if the temperature of the aqueous solvent is higher than 75°C, the viscosity of the oily component will decrease, and the particles will be finely broken by the stirring force, tending to result in particles smaller than the desired particles.

[0044] The oily component can be introduced into the aqueous solvent by, for example, injecting it from above the aqueous solvent or directly into the aqueous solvent via a nozzle or the like using a liquid delivery means such as a liquid delivery pump.

[0045] Next, the mixture of the aqueous solvent and oily component is cooled, preferably to room temperature, under stirring, and the gelling agent in the oily component, which has reached a temperature below its melting point, solidifies the oil, thereby forming oil gel particles in the aqueous solvent.

[0046] After oil gel particles are formed in an aqueous solvent in this manner, the particles are generally separated from the aqueous solvent and dried. The separation and drying method is not particularly limited. For example, the oil gel particles dispersed in an aqueous solvent can be filtered through a mesh smaller than the particle size and then dried. The dried oil particles can be used as a granular skin preparation as is, but to prevent the particles from welding together, fine powder particles can be attached to the surface of the oil gel particles, or the particles can be dispersed in an aqueous gel to form a skin preparation. Furthermore, by using a powder of a water-soluble medicinal ingredient as the fine powder particles, the oil particles can be endowed with the functions of the water-soluble medicinal ingredient (e.g., whitening, preventing dullness, preventing rough skin, moisturizing, etc.).

[0047] (Skin external composition) The oil gel particles produced as described above can be dispersed in an aqueous or oily medium and used as external skin preparations, mainly cosmetics, pharmaceuticals, quasi-drugs, etc. External skin compositions include cosmetics, quasi-drugs, and external pharmaceuticals, and examples thereof include gels, emulsions, beauty serums, creams, lotions, beauty oils, hair oils, essences, packs, lipsticks, foundations, liquid foundations, press powder makeup, blushers, face powders, facial cleansers, body shampoos, slimming agents, hair shampoos, soaps, and also hair growth agents and bath additives, but are of course not limited to these.

[0048] (Other ingredients) The topical composition may contain various water-soluble or oil-soluble components (water-soluble components are contained in the aqueous phase, and oil-soluble components are contained in the oil gel particles). For example, when the topical composition is used as a sun care product, it may contain an ultraviolet screening agent. It may also contain medicinal ingredients such as vitamins, hormones, amino acids, anti-inflammatory agents, antibacterial agents, whitening agents, astringents, cooling agents, and sterols. It may also contain extracts derived from animals, plants, or microorganisms that have various medicinal effects.

[0049] The oil-based component contains an oil-soluble active ingredient, such as an oil-soluble vitamin or an oil-soluble vitamin derivative, such as retinol, retinol palmitate, retinol acetate, tocopherol acetate, or ascorbyl tetra-2-hexyldecanoate, and these active ingredients are encapsulated in the oil gel particles to provide whitening, anti-dullness, anti-rough skin, moisturizing, and other effects. The oil gel particles can be applied efficiently as a skin preparation to areas with skin problems such as rough skin, dullness, and age spots. Furthermore, because they contain almost no water, they can stabilize drugs that are unstable in the presence of water, such as vitamins.

[0050] Furthermore, the oil gel particles can be colored by adding to the oil solution oil-soluble dyes (e.g., Red 225), organic pigments (e.g., Orange No. 204, Red No. 202), lakes of coloring agents (e.g., Orange No. 205, Yellow No. 4, Blue No. 1) (lakes with zirconium, barium, aluminum, etc.), natural pigments (e.g., chlorophyll, β-carotene), inorganic pigment powders (preferably hydrophobized) such as yellow iron oxide, red iron oxide, black iron oxide, titanium oxide, and zinc oxide, pearl pigments such as titanium mica, and glitter agents made of colored plate-like resins. The topical composition of this embodiment can also contain humectants, sequestering agents, neutralizers, pH adjusters, antioxidants, etc.

[0051] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, the unit % used to indicate the amount of each component added means % by mass. [Example]

[0052] [Production Example 1] Method for producing oil gel particles Oil gel particles were prepared by the following method using appropriate combinations of the various components listed in Table 1. Specifically, the oil gel components shown in Tables 2 to 4 (oil agent, gelling agent, and optionally surfactant or functional component) were thoroughly mixed at room temperature and then heated to 140°C in an oil bath to dissolve. 100 g of purified water was added to a separate container, which was then immersed in a hot water bath, adjusted to 40°C, and stirred. 0.5 g of each oil gel component was added to a stirring container containing purified water, stirred for 30 seconds to 1 minute, and particle formation was confirmed. The mixture was then passed through a sieve with 2.35 mm openings and then recovered using a sieve with 1 mm openings. The particles were then washed with water, sized, and dried for one day to prepare oil gel particle samples.

[0053] [Table 1]

[0054] [Test Example 1] Appearance evaluation 1. Particle forming ability After adding the oil phase (oil gel components) to the water phase (purified water) and stirring, if a spherical gel was formed it was rated as 'good'; if it did not emulsify to form particles or if a plate-like or string-like gel was formed instead of a spherical one it was rated as 'bad'; and if an almost spherical gel was formed it was rated as 'good'. 2.Transparency After sieving and recovering the spherical gel, if a transparent gel was formed by visual inspection, it was rated as ◯; if it was slightly cloudy and translucent due to emulsification or crystallization, it was rated as △; if it was cloudy and opaque due to emulsification or crystallization, it was rated as ×. 3. Durability when sieving After sieving and recovering the spherical gel, if the shape did not change before and after washing with water, it was marked as ◯; if the shape changed or collapsed before and after washing with water, it was marked as ×; and if the shape hardly changed before and after washing with water, it was marked as △.

[0055] [Test Example 2] Sensory evaluation When the oil gel particles were picked up and crushed on the skin, those that were easy to crush and spread were rated as ◯, and those that were difficult to crush and spread were rated as ×. ◎ indicates that the particles were particularly easy to spread and smooth.

[0056] [Test Example 3] Instrumental measurement The breaking strength of the oil gel particles was measured using a rheometer (RHEO METER, MODEL: CR-3000EX) manufactured by Sun Scientific Co., Ltd. The breaking strength was measured in advance using a thickness gauge and then subjected to rheometer measurement. The breaking strength was measured using a rheometer equipped with a 12 mm diameter jig. The sample was placed on a disc-shaped sample stage in the rheometer's measurement section and raised at a rate of 5 mm / min. The penetration distance was approximately half the particle size, and the jig was inserted from a state where the sample and jig were in contact, compressing the sample to break it. At this time, breakage was confirmed visually and by touch, and the breaking strength was calculated from the load-strain curve. This measurement was repeated for three samples, and the average value was calculated. The thickness of the oil gel particles used in the measurement was measured and used as the particle size of the sample, and the area was calculated from this particle size, and the load (N) measured previously was divided by the cross-sectional area to obtain the breaking strength (kPa). This "particle size of the sample" was then used as the average particle size.

[0057] [Examples 1 to 7 and Comparative Example 1] Examination of the polarity of oils and surfactants First, oil gel particles were produced according to the method of Production Example 1 using oil gel components of each composition shown in Table 2. Under the conditions of Examples 1 to 3, which did not contain a surfactant, the formation of transparent particles was observed in all cases, and the IOB values ​​of the oil agents at this time were 8.1 or less. Furthermore, under the conditions in which a surfactant was added, the formation of transparent particles was observed in Examples 4 to 6, but no particle formation was observed in Comparative Example 1, suggesting that particle formation is difficult when the mixed HLB value of the oil gel components exceeds 8.5.

[0058] [Table 2]

[0059] [Examples 8 to 15 and Comparative Example 2] Examination of the hardness of oil and gelling agent Next, to examine the influence of oil and gelling agent on the hardness of oil gel particles, oil gel particles were produced according to the method of Production Example 1 using oil gel components of each composition shown in Table 3. Although the strength varies depending on the combination of gelling agent and oil, it was confirmed that particle formation and sieving were possible with a gelling agent in the range of 2 to 50%, and it was also found that the particles in Example 11, in which 35% gelling agent was added, were easy to crush and had a good feel.

[0060] [Table 3]

[0061] [Examples 16 to 25] Examination of additional ingredients To investigate the effects of adding additional components such as various functional ingredients to oil gel particles, oil gel particles were prepared according to the method of Preparation Example 1 using the oil gel components of the compositions shown in Table 4. As a result, it was confirmed that particles were formed and had physical properties similar to those of unencapsulated particles, with respect to transparency and hardness. As shown in Table 4, Example 16 contained silicone oil, Example 17 contained sodium hyaluronate, Example 18 contained ascorbic acid, Example 19 contained retinol, Example 20 contained fragrance (limonene, linalool), Example 21 contained powder (sodium carbonate), Example 22 contained pigment (ultramarine), Example 23 contained vegetable oil (palmitic acid), Example 24 contained vegetable oil (stearic acid), and Example 25 contained an ultraviolet absorber (ethylhexyl methoxycinnamate).

[0062] [Table 4]

[0063] [Manufacturing Example 2] Examination of the manufacturing method of oil gel particles For the components of Example 26 listed in Table 5, a test solution was prepared in the same manner as in Production Example 1, except that the receiving liquid was changed to 10 g of glycerin and 90 g of purified water, and then evaluated. [Table 5]

[0064] [Production Example 3] Method for producing oil gel particles For the components of Example 27 listed in Table 5, a test solution was prepared in the same manner as in Production Example 1, except that the receiving liquid was changed to 90 g of glycerin and 10 g of purified water, and then evaluated.

[0065] [Production Example 4] Method for producing oil gel particles For the components of Example 28 listed in Table 5, a test solution was prepared in the same manner as in Production Example 1, except that the receiving liquid was changed to 10 g of 1,3-butylene glycol and 90 g of purified water, and then evaluated.

[0066] [Production Example 5] Method for producing oil gel particles For the components of Example 29 listed in Table 5, the receiving liquid was changed to 90 g of 1,3-butylene glycol and 10 g of purified water, and the same preparation as in Production Example 1 was carried out, followed by evaluation.

[0067] [Production Example 6] Method for producing oil gel particles For the components of Example 30 listed in Table 5, the receiving liquid was changed to 0.1 g of carboxyvinyl polymer, 0.1 g of polysorbate 80, 10 g of 1,3-butylene glycol, and 89.8 g of purified water, and the same preparation as in Production Example 1 was carried out, followed by evaluation.

[0068] [Production Example 7] Method for producing oil gel particles For the components of Example 32 listed in Table 5, a test solution was prepared in the same manner as in Production Example 1, except that the receiving liquid was changed to 50 g of glycerin and 50 g of purified water, and then evaluated.

[0069] [Production Example 8] Method for producing oil gel particles The components of Example 31 listed in Table 5 were heated to 140°C and melted, then filled into a silicon mold in the form of particles with a particle size of 2 mm, and left to cool at room temperature for one day. The particles were then peeled off from the mold to obtain oil gel particles, which were then sieved and evaluated in the same manner as in Production Example 1.

[0070] [Formulation example of a topical skin composition containing oil gel particles] The following are examples of formulations in which oil gel particles are blended. In all formulations, the formulation was prepared using ingredients other than the oil gel particles, and then the oil gel particles were added and mixed at the end to prepare the formulation.

[0071] [Table 6]

[0072] [Table 7]

[0073] [Table 8]

[0074] [Table 9]

[0075] [Table 10]

[0076] [Example 33] Stability test of retinol encapsulated in oil gel particles The stability of retinol, which has an anti-wrinkle effect as a functional ingredient, encapsulated in oil gel particles was investigated. At the formulation amounts shown in Table 11, dextrin palmitate and silica were mixed with isononyl isononanoate, and then heated to 110 °C to dissolve the oil gel components. Separately, polysorbate 80 was dissolved in an aqueous glycerol solution and heated to 50 °C. After adding and dissolving retinol and tocopherol to the container of the oil gel components, the oil gel components were added while stirring the aqueous glycerol solution containing polysorbate 80 to prepare oil gel particles. The formed particles were collected with a 100-mesh filter and immersed in the outer layer liquid shown in Table 11. This was placed in small portions in glass bottles, wrapped with aluminum foil on the surface to shield from light, and then stored at refrigeration (5 °C) or 40 °C, or stored under natural light (near the window) without shielding from light. After storing for a predetermined period, the amount of retinol remaining in the stored samples was quantified by HPLC according to the following procedure. As a comparative control example, retinol was dissolved in ethanol to a concentration of 0.1 wt / vol% and stored under the same conditions as the above samples.

[0077]

Table 11

[0078] <HPLC Conditions> Measurement Conditions Column: COSMOSIL 5C18-MS-II Packed Column 4.6 mm I.D.×250 mm Solvent: Ethanol / Water (95 / 5) Flow Rate: 1 ml / min Detection: UV325 nm Injection Volume: 10 μl

[0079] The samples stored under each condition were mixed with the above solvent (ethanol / water (95 / 5)) and disrupted by ultrasonic waves. The retinol concentration was adjusted to 20 μg / mL to prepare a sample for HPLC measurement. The retinol concentration after each storage period was quantified by HPLC, and the remaining amounts after 1 day and 14 days when the retinol concentration on day 0 was set to 100 are shown in Table 12 below.

[0080] <HPLC Results>

Table 12

[0081] As shown in Table 12, retinol encapsulated in oil gel particles was more stable than in an ethanol solution under any conditions. In particular, retinol stored in an ethanol solution was almost completely decomposed after 1 day at 40°C under light-shielded conditions, while 97% of retinol encapsulated in oil gel particles remained after storage at 40°C for 14 days under light-shielded conditions, indicating that it was stabilized by encapsulation in oil gel particles. When stored under natural light, all of the retinol stored in the ethanol solution was decomposed after 1 day, while approximately 58% remained when encapsulated in oil gel particles.

[0082] [Example 34] Stability Test of Retinol Palmitate Encapsulated in Oil Gel Particles Using retinol palmitate instead of retinol, storage samples were prepared in the same manner as in Example 33. The compositions of the oil gel particles and the outer layer solution are shown in Table 13 below. As a comparative control example, retinol palmitate was dissolved in ethanol to a concentration of 1 wt / vol% and stored in the same environment as the above samples.

[0083]

Table 13

[0084] <HPLC Conditions> Measurement Conditions Column: COSMOSIL 5C18-MS-II Packed Column 4.6 mm I.D. × 250 mm Solvent: Ethanol / Water (95 / 5) Flow Rate: 1 ml / min Detection: UV325 nm Injection Volume: 10 μl

[0085] The samples stored under each condition were mixed with the above solvent (ethanol / water (95 / 5)) and disrupted by ultrasonication. The concentration was adjusted to 13 ppm (wt / vol) and used as a sample for HPLC measurement. The retinol palmitate concentration after each storage period was quantified by HPLC. The remaining amounts after 1 day and 14 days, with the retinol palmitate concentration on day 0 (the start of each storage period) set at 100, are shown in Table 12 below.

[0086] [Table 14]

[0087] As shown in Table 14, retinol palmitate stored in solution was almost completely decomposed after 14 days even at 25°C under light-shielded conditions, but more than 97% of retinol encapsulated in oil gel particles remained after 14 days at both 25°C and 40°C, demonstrating that encapsulation in oil gel particles stabilizes retinol. When stored under natural light, retinol stored in ethanol solution was almost completely decomposed after one day, but when encapsulated in oil gel particles, approximately 69% remained.

[0088] [Examples 35 to 40] Evaluation of topical skin compositions containing oil gel particles In order to investigate the feel and dispersibility when oil gel particles were dispersed in an oily medium, oil gel particles were produced according to the method of Production Example 1 using the components (isononyl isononanoate and dextrin palmitate) shown in Table 15. After particle formation, the particles were passed through a sieve with a mesh size of 1.4 mm, and then recovered using a sieve with a mesh size of 0.5 mm, and dispersed in the outer layer liquid shown in Table 15 at a weight ratio of oil gel particles:outer layer liquid = 1:9. Thereafter, the feel and dispersibility of the oil gel particles were evaluated by the following method.

[0089] Evaluation method Texture: After the oil gel particles dispersed in the outer layer liquid were picked up and spread on the skin, those that stretched were rated as ◯, and those that did not stretch were rated as ×. Dispersibility: The oil gel particles dispersed in the outer layer liquid were filled into the cell of a spectrophotometer (Single monochromator UV-2600i, Shimadzu Corporation), and the dispersion state was visually evaluated after one day. Figure 1 shows an overview of this dispersibility (absorbance test). Uniform dispersion was evaluated as ◯, partial sedimentation as △, and complete sedimentation as ×. Simultaneously, the absorbance (660 nm) of the particles and outer layer liquid was measured using only the outer layer liquid as a blank. The percentage change in absorbance between immediately after filling and after leaving the container undisturbed for one day was calculated using the following formula (1). The results are shown in Table 15. [Formula 1] Absorbance change rate (%) = (absorbance (1 day after filling) / absorbance (immediately after filling)) x 100

[0090] [Table 15]

[0091] As shown in Table 15, it was confirmed that a composition for external use on skin having a good dispersion and feel of oil gel particles could be prepared by using a predetermined composition of the outer layer liquid.

[0092] [Examples 41 and 42]: Oil gel particles The oil gel particles shown in Table 16 were prepared. Example 41 is an example in which an enzyme (protease) is encapsulated as the encapsulated functional component. Example 42 is an example in which a specific colorant (a component or pigment used in makeup, etc.) is encapsulated as the encapsulated functional component.

[0093] [Table 16]

[0094] The oil gel particles described in Example 41 in Table 16 were prepared as follows. The oil gel components (oil, etc.) shown in Example 41 were thoroughly mixed at room temperature (25°C) and then heated to 110°C in an oil bath to dissolve. 0.5 g of each oil gel component was added to a stirring vessel containing 100 g of glycerin, and the mixture was stirred for 30 seconds to 5 minutes to confirm the formation of particles. The mixture was then passed through a sieve with 2.35 mm openings and then recovered through a sieve with 1 mm openings. The particles were then washed with water, sized, and dried for one day to prepare the oil gel particle samples described in Table 16. The prepared oil gel particles were also evaluated for appearance, etc. (evaluated in the same manner) as listed in Tables 1 to 3, as shown in Table 16.

[0095] The oil gel particles described in Example 42 in Table 16 were prepared as follows. The oil gel components (oil, etc.) shown in Example 42 were thoroughly mixed at room temperature (25°C) and then heated to 110°C in an oil bath to dissolve. 75 g of glycerin and 25 g of purified water were added to a separate container and stirred. 0.5 g of each oil gel component was added to a stirring container containing glycerin and purified water, and then stirred for 30 seconds to 5 minutes to confirm particle formation. The mixture was then passed through a sieve with 2.35 mm openings and then recovered through a sieve with 1 mm openings. Subsequently, the particles were washed with water, sized, and dried for one day to prepare the oil gel particle samples described in Table 16. The prepared oil gel particles were also evaluated for appearance, etc. (evaluated in the same manner) as listed in Tables 1 to 3, as shown in Table 16.

[0096] The components contained in the oil gel particles shown in Table 16 were the same as those shown in Table 1 above, except for the following: Protease: Protease CL-15, Nagase ChemteX Corporation Yellow iron oxide: Tarox LL-100P, Titanium Industries Co., Ltd. Bengala: Tarox R-516P, Titanium Industry Co., Ltd. Black iron oxide: Tarox BL-100, Titanium Industries Co., Ltd. Titanium oxide: MT-500B, Teika Corporation

[0097] The oil gel particles prepared in Example 41 contained the enzyme without being deactivated. Accelerated degradation tests based on the Arrhenius equation (Sakagami Shigeyuki, Kawase Akito: Storage Stability Tests of Pharmaceuticals, SCAS NEWS, 2000-1, pp. 7-11) were conducted on the oil gel of Example 41 at 40°C for one month and at 50°C for one month. The results of the tests showed that the enzyme was deactivated within one month under both conditions.

[0098] The oil gel particles prepared in Example 42 are a model in which, when crushed and applied to the skin, the makeup ingredients are spread over the skin, providing an emollient effect while making it easy to experience the makeup effect. The oil gel particles of Example 42 are particles in which the makeup ingredients are solidified in particulate form, and the particles themselves have a makeup effect. The oil gel particles of Example 42 can, for example, eliminate the need to uniformly mix the makeup ingredients into a base material when producing cosmetics containing these oil gel particles. Note that the oil gel particles of Example 42 lacked transparency because they contained the specified amounts of the pigment and titanium oxide.

[0099] Table 17 below shows a formulation example of a composition for external use on skin containing the oil gel particles of Example 42. As shown in Table 6 above, the formulation example was prepared using ingredients other than the oil gel particles, and then the oil gel particles of Example 42 were added and mixed last to prepare the formulation example.

[0100] [Table 17]

[0101] [Production Example 9] Examination of the production method of oil gel particles The oil gel particles of Example 43 listed in Table 18 were prepared as follows. The oil gel components (oil, etc.) shown in Table 18 were thoroughly mixed at room temperature (25°C) and then heated to 110°C in an oil bath to dissolve. 0.5 g of each oil gel component was placed in a stirring vessel containing 100 g of glycerin, and the mixture was stirred for 30 seconds to 5 minutes to confirm the formation of particles. The mixture was then passed through a sieve with 2.35 mm openings and then recovered through a sieve with 1 mm openings. The particles were then washed with water, sized, and dried for one day to prepare the oil gel particle samples listed in Table 18. The prepared oil gel particles were also evaluated for appearance, etc. (evaluated in the same manner) as listed in Tables 1 to 3, as shown in Table 18.

[0102] [Table 18]

[0103] As shown in Table 18, oil gel particles with the predetermined evaluation results (particle forming ability, etc.) were successfully produced.

[0104] [Examples 7 to 9]: Mixtures containing oil gel particles of Example 33 The oil gel particles of Example 33 were used to prepare the examples (mixtures) shown in Table 19 below. The examples were prepared by adding a lubricant or silk powder to the oil gel particles of Example 33 and mixing them in the compositions shown in Table 19.

[0105] In the examples shown in Table 19, the following lubricants or silk powders were used. Lubricant (Lauroyl Lysine): Amihope TM LL, Ajinomoto Co., Inc. Lubricant (talc): Crown Talc JS Matsumura Sangyo Co., Ltd. Silk powder: Silkgen G Powder (N), Ichimaru Pharcos Co., Ltd.

[0106] [Table 19]

[0107] In the examples shown in Table 19, the lubricant or silk powder is adsorbed onto the surface of the oil gel particles, suppressing particle-to-particle adhesion and improving the fluidity of the oil gel particles. This improvement makes it easier for cosmetic formulators to handle the oil gel particles as granules. By using the examples shown in Table 19, it becomes easier to create cosmetics that, when crushed, feel like oil is being directly applied and have a more emollient effect. [Industrial Applicability]

[0108] It has been confirmed that the oil gel particles of the present invention have a highly transparent appearance and, when applied to the skin, have a moist feel characteristic of oily agents. Therefore, the oil gel particles of the present invention and topical preparations containing the same can be used as facial, body, or hair cosmetics, such as lotions, emulsions, creams, and packs.

Claims

1. The oil gel particles comprise 50 to 99% by mass of an oil agent, 0.5 to 50% by mass of a gelling agent, and 0.5 to 10% by mass of a surfactant, and the oil agent and the surfactant have a mixed HLB value of 8.5 or less.

2. 2. The oil gel particles according to claim 1, wherein the average particle size is 100 to 2000 μm.

3. 3. The oil gel particles according to claim 1, wherein the oil agent is at least one selected from the group consisting of hydrocarbon oils, ester oils, silicone oils, and vegetable oils.

4. 4. The oil gel particles according to claim 1, wherein the gelling agent is a dextrin fatty acid ester, an inulin fatty acid ester, and / or an amino acid-based oil gelling agent.

5. A composition for external use on skin, comprising the oil gel particles according to any one of claims 1 to 4 in a dispersed state in an aqueous medium or an oily medium.

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