W / O / W emulsion containing inositol and method for producing the same

Abstract

The purpose of the present invention is to provide a W / O / W emulsion that contains inositol and has excellent stability over time, and a method for producing the W / O / W emulsion. The present invention relates to, inter alia, a W / O / W emulsion containing an inner water phase, an oil phase, and an outer water phase, wherein inositol is contained in the inner water phase.

Description

[Technical Field]

[0001] The present invention relates to a W / O / W emulsion, a method for producing the same, and the like. More specifically, the present invention relates to a W / O / W emulsion containing inositol and having good stability over time, a method for producing the same, and the like. [Background Art]

[0002] A W / O / W (water-in-oil-in-water) emulsion is a multiple emulsion obtained by further emulsifying and dispersing a water-in-oil (W / O) emulsion in an aqueous phase (outer aqueous phase). W / O / W emulsions are known as a formulation technique that can enhance the transdermal absorption of active ingredients compared to other emulsion types (Non-Patent Document 1), and are expected to be applied to various uses such as cosmetics, foods, and pharmaceuticals.

[0003] On the other hand, inositol is known to have a moisturizing effect, an effect of regulating sebum secretion, and the like. Patent Document 1 describes an external pharmaceutical composition containing inositol and being in an oil-in-water emulsion form. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2019-218319 [Non-Patent Documents]

[0005] [Non-Patent Document 1] Fragrance Journal, 1989, No. 4, pp. 88-93 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] Patent Document 1 describes that adding inositol to the aqueous phase of an oil-in-water emulsion cream improves emulsion stability. However, Patent Document 1 does not describe a W / O / W type emulsion containing inositol. The aqueous phase of an oil-in-water emulsion corresponds to the outer aqueous phase in a W / O / W type emulsion.

[0007] As mentioned above, inositol has moisturizing and sebum secretion regulating properties, making W / O / W emulsions containing inositol useful, for example, in the cosmetics field. Therefore, the inventors investigated W / O / W emulsions containing inositol. Cosmetics are sometimes exposed to harsh conditions during distribution and consumer use, so good long-term stability is required. However, it was found that when inositol is added to a W / O / W emulsion, the stability of the W / O / W emulsion decreases, and separation (phase separation) may occur more easily. Once a W / O / W emulsion separates, it cannot be returned to its original emulsion state.

[0008] The present invention aims to provide a W / O / W type emulsion containing inositol and exhibiting good long-term stability, as well as a method for producing the same. [Means for solving the problem]

[0009] The inventors of this invention have diligently conducted research to obtain a W / O / W type emulsion containing inositol and exhibiting good long-term stability. As a result, they have discovered that including inositol in the internal aqueous phase of a W / O / W type emulsion stabilizes the emulsion.

[0010] In other words, the present invention is not limited to the following, but relates to W / O / W type emulsions and methods for producing the same. [1] A W / O / W type emulsion comprising an internal aqueous phase, an oil phase, and an external aqueous phase, wherein the internal aqueous phase contains inositol. [2] The W / O / W type emulsion described in [1] above, wherein the outer aqueous phase does not contain inositol. [3] The W / O / W type emulsion described in [1] or [2] above, wherein the inositol content is 0.01 to 1.4% by weight. [4] A W / O / W type emulsion according to any one of [1] to [3] above, wherein the oil phase contains a solid oily component and a silicone-based surfactant, and the outer aqueous phase contains a water-soluble polymer. [5] The W / O / W type emulsion described in [4] above, wherein the HLB value of the silicone-based surfactant is 7 or less. [6] The W / O / W emulsion according to [4] or [5] above, wherein the silicone-based surfactant is a silicone-based surfactant having a polyether group and an alkyl group. [7] The W / O / W emulsion according to [6] above, wherein the silicone-based surfactant having the polyether group and alkyl group is cetyl PEG / PPG-10 / 1 dimethicone or lauryl PEG-9 polydimethylsiloxyethyl dimethicone. [8] A W / O / W type emulsion according to any of [4] to [7] above, wherein the content of the above solid oily component is 0.5% by weight or more. [9] A W / O / W type emulsion according to any of [4] to [8] above, wherein the solid oil component is a wax.

[10] The W / O / W type emulsion according to any one of [4] to [9] above, wherein the water-soluble polymer is an alkyl acrylate methacrylate copolymer.

[11] A W / O / W type emulsion according to any of [1] to

[10] above, further containing a metal salt in the internal aqueous phase.

[12] A W / O / W type emulsion according to any of [1] to

[11] above, wherein the weight ratio of the internal aqueous phase and the oil phase is internal aqueous phase / oil phase = 10 / 90 to 90 / 10.

[13] A W / O / W type emulsion, which is an external preparation, as described in any of [1] to

[12] above.

[14] A W / O / W type emulsion, which is a topical skin preparation, as described in any of [1] to

[13] above.

[15] A W / O / W type emulsion according to any of [1] to

[14] above, which is a cream or lotion.

[16] A method for producing a W / O / W emulsion, comprising the steps of: preparing a W / O type emulsion by mixing an internal aqueous phase containing inositol with an oil phase and emulsifying it; and mixing the prepared W / O type emulsion with an external aqueous phase and emulsifying it.

[17] The manufacturing method described in

[16] above, wherein the outer aqueous phase does not contain inositol.

[18] The manufacturing method according to

[16] or

[17] above, wherein the oil phase contains a solid oily component and a silicone-based surfactant, and the outer aqueous phase contains a water-soluble polymer.

[19] A manufacturing method according to any of

[16] to

[18] above, wherein the internal aqueous phase and the oil phase are mixed in a weight ratio of internal aqueous phase / oil phase = 10 / 90 to 90 / 10. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a W / O / W type emulsion containing inositol and having good long-term stability, as well as a method for producing the same. The W / O / W type emulsion of the present invention is useful, for example, as a topical skin preparation such as cosmetics. [Modes for carrying out the invention]

[0012] The following are examples of embodiments of the present invention. (W / O / W type emulsion) The W / O / W emulsion of the present invention is a W / O / W emulsion comprising an internal aqueous phase, an oil phase, and an external aqueous phase, wherein the internal aqueous phase contains inositol. The W / O / W type emulsion of the present invention is typically a W / O / W type emulsion comprising an internal aqueous phase, an oil phase in which the internal aqueous phase is dispersed (emulsified), and an external aqueous phase in which the oil phase is dispersed (emulsified). The W / O / W type emulsion of the present invention may consist of the above-mentioned internal aqueous phase, oil phase, and external aqueous phase. In the W / O / W type emulsion, a W / O type emulsion in which the internal aqueous phase (internal aqueous phase droplets) is dispersed (emulsified) in the oil phase is dispersed (emulsified) in the external aqueous phase. The W / O / W emulsion of the present invention has good stability over time and is less prone to separation, so it is useful in fields such as cosmetics.

[0013] The terms "inner aqueous phase", "oil phase" and "outer aqueous phase" as used in the present invention may refer to either the respective phases of the W / O / W emulsion or each solution respectively containing the component of each phase used for producing the W / O / W emulsion.

[0014] (Inner Aqueous Phase Components) The W / O / W emulsion of the present invention contains inositol in the inner aqueous phase. When a W / O / W emulsion contains inositol, incorporating inositol in the inner aqueous phase results in improved stability over time of the W / O / W emulsion. Inositol (1,2,3,4,5,6-cyclohexanehexol) is a compound having a structure in which one hydrogen atom on each carbon of cyclohexane is substituted with a hydroxy group. Due to combinations of different configurations of the hydroxy groups, there are 9 stereoisomers of inositol: myo-inositol, allo-inositol, D-chiro-inositol, L-chiro-inositol, cis-inositol, epi-inositol, muco-inositol, neo-inositol, and scyllo-inositol. In the present invention, inositol may be one of the aforementioned 9 types, or a combination of two or more thereof. In the present invention, inositol is preferably myo-inositol (cis-1,2,3,5-trans-4,6-cyclohexanehexol).

[0015] The content of inositol in the W / O / W emulsion of the present invention may be 0.001% by weight or more, preferably 0.01% by weight or more, more preferably 0.05% by weight or more, still more preferably 0.08% by weight or more, particularly preferably 0.1% by weight or more. Further, the content of inositol in the W / O / W emulsion may be 0.2% by weight or more, 0.5% by weight or more, or 1% by weight or more. Further, the content of inositol in the W / O / W emulsion is preferably 2% by weight or less, more preferably 1.5% by weight or less, still more preferably 1.4% by weight or less, even more preferably 1% by weight or less, particularly preferably 0.5% by weight or less, and most preferably 0.2% by weight or less. Further, the content of inositol in the W / O / W emulsion may be 0.1% by weight or less or 0.08% by weight or less. When the content of inositol falls within the above range, the stability over time of the W / O / W emulsion is further improved. Therefore, even when the W / O / W emulsion is stored for a long period of time, separation is less likely to occur, and the W / O / W emulsion exhibits long-term storage stability. In one aspect, the content of inositol in the W / O / W emulsion may be 0.001 to 2% by weight, preferably 0.01 to 1.5% by weight, more preferably 0.01 to 1.4% by weight, more preferably 0.05 to 1.4% by weight, more preferably 0.08 to 1.4% by weight, still more preferably 0.1 to 1.4% by weight, even more preferably 0.1 to 1% by weight, particularly preferably 0.1 to 0.5% by weight, and most preferably 0.1 to 0.2% by weight. The W / O / W emulsion of the present invention preferably contains the above amount of inositol in the inner aqueous phase. Inositol in the inner aqueous phase can be measured by separating the inner aqueous phase, oil phase, and outer aqueous phase of the W / O / W emulsion using a known method (e.g., centrifugation), and then performing measurement by a known method (e.g., high performance liquid chromatography (HPLC)).

[0016] Inositol is known to have moisturizing effects, sebum secretion regulating effects, and the like. The W / O / W emulsion of the present invention can be used, for example, to obtain effects derived from inositol.

[0017] The W / O / W type emulsion of the present invention preferably further contains a metal salt in the internal aqueous phase. Including a metal salt as a component of the internal aqueous phase further improves the time-dependent stability of the W / O / W type emulsion. The metal salt is not particularly limited, but magnesium sulfate, amino acid salts such as sodium citrate and sodium glutamate, sodium lactate, and sodium chloride are preferred, and magnesium sulfate is more preferred. One or more metal salts can be used. When the W / O / W type emulsion contains a metal salt, the content is not particularly limited, but may be, for example, 0.001 to 10% by weight, preferably 0.01 to 5% by weight, and more preferably 0.1 to 2% by weight in the W / O / W type emulsion.

[0018] The internal aqueous phase may contain water-soluble active ingredients other than inositol, as long as it does not impair the effects of the present invention. The water-soluble active ingredients other than inositol may be one type or two or more types. Examples of water-soluble active ingredients other than inositol include ascorbic acid derivatives (vitamin C derivatives) known as whitening ingredients, arbutin, chamomile ET, tranexamic acid, placenta extract, rucinol, hydroquinone, etc. Also, plant extracts and other beauty ingredients exemplified below are also examples.

[0019] When the W / O / W emulsion contains a water-soluble active ingredient other than inositol, the amount is not particularly limited, but may be, for example, 0.0001 to 10% by weight, preferably 0.001 to 5% by weight, more preferably 0.005 to 5% by weight, and even more preferably 0.005 to 2% by weight in the W / O / W emulsion. In one embodiment, it is also preferable that the amount of the water-soluble active ingredient other than inositol in the W / O / W emulsion be 0.001 to 2% by weight.

[0020] (Oil phase components) The oil phase contains oily components. Liquid oily components and solid oily components can be used. There may be one type of oily component or two or more types. The oil phase typically contains liquid oily components. These liquid oily components only need to be liquid at room temperature. Examples of liquid oily components include natural animal and vegetable oils and fats, hydrocarbon oils, ester oils, silicone oils, higher alcohols, and higher fatty acids, and one or more of these can be used.

[0021] Examples of natural animal and vegetable oils include avocado oil, linseed oil, almond oil, olive oil, cocoa oil, tung oil, wheat germ oil, sesame oil, rice germ oil, rice bran oil, safflower oil, soybean oil, evening primrose oil, camellia oil, corn oil, rapeseed oil, peach kernel oil, palm oil, palm kernel oil, castor oil, sunflower oil, grape oil, jojoba oil, macadamia nut oil, mink oil, cottonseed oil, coconut oil, peanut oil, and rosehip oil. Examples of hydrocarbon oils include α-olefin oligomers, squalane, squalene, and liquid paraffin.

[0022] As ester oils, diisobutyl adipate, 2-hexyldecyl adipate, di-2-heptylundecyl adipate, isostearyl isostearate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, neopentyl glycol di-2-ethylhexanoate, trimethylolpropane tri-2-ethylhexanoate, pentaerythritol tetra-2-ethylhexanoate, cetyl octanoate, oleyl oleate, octyldodecyl oleate, decyl oleate, neopentyl glycol dicaprate Examples include 2-ethylhexyl succinate, isocetyl stearate, butyl stearate, diisopropyl sebacate, cetyl lactate, tetradecyl lactate, isopropyl myristate, octyldodecyl myristate, cetyl myristate, myristyl myristate, octyl palmitate, 2-ethylhexyl palmitate, 2-hexyldecyl palmitate, 2-heptylundecyl palmitate, phytosteryl oleate, diisostearyl malate, paramethoxycinnamate, pentaerythritol tetralosinate, etc.

[0023] Examples of silicone oils include dimethylpolysiloxane, highly polymerized methylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, octamethylcyclotetrasiloxane, octamethylcyclopentasiloxane, decamethylcyclohexasiloxane, stearoxysilicone, and other higher alkoxy-modified silicones, alkyl-modified silicones, and higher fatty acid ester-modified silicones.

[0024] Examples of higher alcohols include octyldodecanol, isostearyl alcohol, and oleyl alcohol. Examples of higher fatty acids include isostearic acid, oleic acid, linoleic acid, and linolenic acid. In one embodiment, hydrocarbon oil is preferred as the liquid oily component. In one embodiment, squalane is more preferred as the liquid oily component.

[0025] In the W / O / W type emulsion of the present invention, it is preferable that the oil phase contains a solid oily component and a silicone-based surfactant. The presence of a solid oily component and a silicone-based surfactant in the oil phase further improves the long-term stability of the W / O / W type emulsion. Furthermore, it is preferable that the oil phase does not contain inositol.

[0026] By including a solid oily component as an oil phase component, the viscosity of the oil phase can be increased and the fluidity of the internal water phase can be reduced. This further improves the stability of the W / O / W type emulsion. The solid oily component is not particularly limited, but can be selected from solid fats and oils, waxes, hydrocarbons, higher fatty acids, higher alcohols, esters, silicones, etc., with solid fats and oils and waxes being particularly preferred. Examples of solid fats and oils include cocoa butter, coconut oil, palm oil, palm kernel oil, hydrogenated oil, hydrogenated castor oil, Japanese wax, and shea butter. Examples of waxes include microcrystalline wax, beeswax, carnauba wax, candelilla wax, and lanolin. Among these, wax is preferred as the solid oily component, and microcrystalline wax is more preferred.

[0027] When a W / O / W type emulsion contains a solid oily component, the content of the solid oily component is not particularly limited, but is preferably, for example, 0.3% by weight or more, more preferably 0.5% by weight or more, and preferably 10% by weight or less, and more preferably 5% by weight or less, in the W / O / W type emulsion. In one embodiment, the content of the solid oily component in the W / O / W type emulsion is preferably 0.3 to 10% by weight, and more preferably 0.5 to 5% by weight. When wax (preferably microcrystalline wax) is used, the content of the wax in the W / O / W type emulsion is preferably 0.4% by weight or more, more preferably 0.5% by weight or more, and preferably 10% by weight or less, and more preferably 5% by weight or less. In one embodiment, when a W / O / W type emulsion contains wax, its content is preferably 0.4 to 10% by weight, and more preferably 0.5 to 5% by weight, in the W / O / W type emulsion.

[0028] Silicone-based surfactants are surfactants having a structure in which hydrophilic substituents are introduced into silicone, and by changing the type of hydrophilic substituent, surfactants suitable for various applications can be obtained. In the present invention, there are no particular limitations as long as the surfactant is silicone-based, but for example, polyether-modified silicone-based surfactants in which the substituent is a polyether are preferred, and silicone-based surfactants having a polyether group and an alkyl group are more preferred. Furthermore, the silicone-based surfactant is preferably one with an HLB value of 7 or less, more preferably one with an HLB value of 6 or less, and even more preferably one with an HLB value of 2.5 to 5.5. When the HLB value of the silicone-based surfactant is within the above range, an emulsion with better long-term stability can be obtained.

[0029] Examples of silicone-based surfactants containing polyether groups include PEG-11 methyl ether dimethicone, PEG / PPG-20 / 22 butyl ether dimethicone, PEG-9 dimethicone, PEG-3 dimethicone, PEG-9 methyl ether dimethicone, PEG-10 dimethicone, PEG-32 methyl ether dimethicone, polysilicone-13, PEG-9 polydimethylsiloxyethyl dimethicone, PEG / PPG-19 / 19 dimethicone, (dimethicone / (PEG-10 / 15)) crosspolymer, cetyl PEG / PPG-10 / 1 dimethicone (HLB 5.0), and lauryl PEG-9 polydimethylsiloxyethyl dimethicone (HLB 3.0). Examples of silicone-based surfactants having a polyether group and an alkyl group include lauryl or cetyl dimethicone copolyol, with cetyl PEG / PPG-10 / 1 dimethicone and lauryl PEG-9 polydimethylsiloxyethyl dimethicone being particularly preferred examples. The above silicone-based surfactants may be used individually or in combination of two or more.

[0030] If the W / O / W emulsion contains a silicone-based surfactant, its content may be, for example, 0.1 to 15.0% by weight, preferably 0.5 to 12.5% ​​by weight, and more preferably 1.0 to 10.0% by weight, in the W / O / W emulsion.

[0031] Furthermore, the oil phase component can optionally contain oil-soluble active ingredients, and the type is not particularly limited. By further including oil-soluble active ingredients, for example, cosmetics that combine the functions derived from inositol and oil-soluble active ingredients can be manufactured. In addition, the W / O / W type emulsion of the present invention can contain plant extracts and other beauty ingredients as oil-soluble active ingredients, as exemplified below.

[0032] For example, by including a tocopherol derivative (vitamin E derivative) in the oil phase, it is possible to further add blood circulation promoting effects, antioxidant effects, and skin softening effects. When the W / O / W type emulsion contains an oil-soluble active ingredient, its content may be, for example, 0.0001 to 10% by weight, preferably 0.0005 to 5% by weight, and more preferably 0.001 to 2% by weight in the W / O / W type emulsion.

[0033] (External aqueous phase component) In the present invention, the outer aqueous phase may contain inositol, but it is preferable that it does not. This is because the less inositol contained in the outer aqueous phase, the better the time-dependent stability of the W / O / W type emulsion. The amount of inositol contained in the outer aqueous phase is preferably 0.5% by weight or less, more preferably 0.3% by weight or less, and even more preferably 0.1% by weight or less in the W / O / W type emulsion.

[0034] In the present invention, it is preferable that the outer aqueous phase contains a water-soluble polymer. Including a water-soluble polymer in the outer aqueous phase further improves the time-dependent stability of the W / O / W type emulsion. A water-soluble polymer known as a thickener can be used as the water-soluble polymer. Since the water-soluble polymer increases the viscosity of the outer aqueous phase and reduces the fluidity of the W / O type emulsion, it is effective in preventing aggregation of W / O type emulsions.

[0035] One preferred embodiment of the W / O / W type emulsion of the present invention is a W / O / W type emulsion containing inositol in the internal aqueous phase, a solid oily component and a silicone-based surfactant in the oil phase, and a water-soluble polymer in the external aqueous phase. It is also preferable that the external aqueous phase does not contain inositol.

[0036] The water-soluble polymer used in the present invention is not particularly limited, and known water-soluble polymers can be used, but examples include natural water-soluble polymers, semi-synthetic water-soluble polymers, and synthetic water-soluble polymers. Examples of natural water-soluble polymers include plant-derived polymers such as arabic gum, guar gum, carrageenan, pectin, agar, quince seed (marmelo), and starch (rice, corn, potato, wheat); microbial polymers such as xanthan gum, dextran, and pullulan; and animal-derived polymers such as collagen, casein, albumin, and gelatin. Examples of semi-synthetic water-soluble polymers include starch-based polymers such as carboxymethyl starch and methylhydroxypropyl starch; cellulose-based polymers such as methylcellulose, nitrocellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium carboxymethylcellulose (CMC), crystalline cellulose, and cellulose powder; and alginate-based polymers such as sodium alginate and propylene glycol alginate. Examples of synthetic water-soluble polymers include vinyl polymers such as polyvinyl alcohol, polyvinyl methyl ether, and carboxyvinyl polymer (carbomer); polyoxyethylene polyoxypropylene copolymer polymers; acrylic polymers such as sodium polyacrylate, polyacrylamide, and alkyl methacrylate copolymer (acrylic acid-alkyl methacrylate copolymer); polyethyleneimine, cationic polymers, and the like. A single water-soluble polymer may be used, or two or more may be used in combination. Acrylic polymers are preferred as water-soluble polymers, and alkyl methacrylate copolymers are more preferred. The W / O / W type emulsion of the present invention preferably contains an alkyl acrylate methacrylate copolymer. If the W / O / W type emulsion contains a water-soluble polymer, its content is, for example, 0.001 to 10% by weight, preferably 0.005 to 5% by weight, and more preferably 0.01 to 2% by weight, in the W / O / W type emulsion.

[0037] Other components in the outer aqueous phase are not particularly limited, but may include components known to contribute to the stability of the emulsion, such as polyoxyethylene surfactants. The polyoxyethylene surfactant is not particularly limited, but polyoxyethylene sorbitan monooleate, etc., can be used. When the W / O / W emulsion contains a polyoxyethylene surfactant, its content may be, for example, 0.01 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 1 to 5% by weight, in the W / O / W emulsion.

[0038] (others) In addition to the above-mentioned components, the W / O / W type emulsion of the present invention may appropriately contain various components commonly used in cosmetics, quasi-drugs, pharmaceuticals, fragrances, etc., such as water, emulsifiers, humectants, thickeners, active ingredients, preservatives, pigments, powders, pH adjusters, UV absorbers, antioxidants, fragrances, etc.

[0039] Furthermore, as described above, the W / O / W type emulsion of the present invention may contain either water-soluble or oil-soluble active ingredients.

[0040] Examples of active ingredients include collagen, hyaluronic acid, elastin, proteoglycans, ceramides, placenta, astaxanthin, polyphenols, yeast, amino acids, and peptides (such as acetyl hexapeptide-8). Furthermore, plant extracts can be incorporated as active ingredients, such as indigo leaf, red grape, rehmannia glutinosa, hemp seed, angelica tree, adzuki bean, acerola, catechu, avocado, flax, hydrangea, gynostemma pentaphyllum, marshmallow, arnica, aloe, aloe vera, apricot kernel, strawberry, fig or its leaves, ginkgo leaf, ginkgo nut, rice seed or seed coat, nettle, ylang-ylang, turmeric, mallow, hollyhock, selfheal, plum or its pulp, oolong tea, Satsuma mandarin (dried citrus peel), etc. Elaeagnus multiflora, Rubus parvifolius, Enokitake mushroom, Cassia obtusifolia, Elderberry fruit, Sophora japonica, Astragalus membranaceus, Coptis japonica, Plantain, Crataegus monogyna, Crataegus sibiricus, Barley, Okra fruit, Panax ginseng, Oak, Hypericum perforatum, Hypericum erectum, Lamium album, Japanese walnut, Lilium lancifolium, Lilium japonicum, Ononis, Elm, Strawberry, Watercress, Watercress, Orchid Japanese parsley, olive, oregano, orange fruit or peel, Rehmannia glutinosa, cocoa seeds, persimmon or its leaves, Curcuma zedoaria, oak (Quercus dentata), birch or weeping birch, pumpkin, cattail, chamomile / Roman chamomile, guarana seeds, quince, Garcinia, river willow, Trametes versicolor, Artemisia capillaris, licorice, hemp, Kanto, canna, raspberry, kiwi fruit, chrysanthemum, Catalpa, dock, kijitsu, ivy, tree aloe, tree mint, cinchona, cinchona (cinnamon, red cinchona), cabbage, unripe cabbage, cucumber Melon, kumquat fruit, betel nut, guava fruit, guayule, Quercus infectria (gall), kukui nut, goji berry (goji berry, goji berry fruit, goji berry leaves, goji berry bark), kudzu (kudzu root), camphor tree, gooseberry fruit, gardenia, bamboo grass, verbena, Sophora flavescens, cranberry fruit, chestnut or its inner skin, grapefruit, black flowering hibiscus, Alpinia zerumbet (leaves), bay laurel, gentian, gentian rhizome / root, black tea, golden scutellaria (yellow scutellaria), lingonberry, pepper, coffee beans, burdock (burdock, burdock seeds), sesame, sesame grass, scrophularia, rice / rice bran (red bran,White rice bran, rice oil, hydrolyzed rice extract, konjac, cherry blossoms (Oshima cherry, mountain cherry, Ooyama cherry, Edohigashi, Mamezakura, Miyamazakura, Somei Yoshino, Takanezakura, Kasumizakura, Chojizakura, Kohigan, Satozakura, Kanzakura) leaves, flowers, fruits, and bark (cherry bark), cherries, pomegranates, sweet potatoes, sugarcane, sugar beets, salvia (sage), Japanese pepper, shea (Karite), shiitake mushrooms, asters, perilla, green perilla, crinkled perilla, firm perilla (perilla leaves, perilla seeds), linden, field mushroom, beech mushroom, white oyster mushroom Spiraea, potato, peony, peony root, ginger, sweet flag (Acorus calamus, sweet flag root), white iris, white ivy flower, watermelon, honeysuckle (Lonicera japonica), stevia, strawberry fruit, horsetail, stevia, plum fruit, Scots pine cone, European larch, European ivy, European walnut, European hawthorn, European dandelion, European horse chestnut (horse chestnut), European pear (fruit, branches), European snowdrop, European yarrow (millfoil), European rose, European mint, European marsh mint, zebra rhombea Oi, water dropwort, celery, angelica tree, gentian, buckwheat seeds, rhubarb, radish, soybean, bitter orange (citronella peel, bitter fruit), thyme (wild thyme), damask rose (flower), onion, magnolia, Japanese angelica tree or its root bark, dandelion or white dandelion / Mongolian dandelion, cherry fruit, Korean ginseng, evening primrose, camellia, centella asiatica, dayflower, creeping bean, Polygonum multiflorum, duberry fruit, winter melon, chili pepper, angelica tree, marigold, corn or maize Koshige, Dokudami, Tokon (root), Tochu (Eucommia ulmoides, Eucommia ulmoides leaves), Tomato, Tormentilla, Nagaimo / Yamaimo, Natsumikan, Jujube, Nankinmame, Nandina (Nandina fruit), Nikuzuku, Kei / Ninkei (Cinnamon bark / Cinnamon), Chives, Garlic, Noibara (Rosa multiflora fruit), Yarrow, Wild rose, Wild peach, Palm, Pineapple fruit, Basil, Lotus (Lotus seed), Parsley (Dutch parsley), Mint (Peppermint, Peppermint leaves), Job's tears (Coix seed), Banana, Oriental mint, Vanilla beans, Papaya, Paprika, Hamamelis (Witch hazel leaves), Rose, Belamcanda chinensis, Isodon japonicus (Longevity grass),Water chestnut, cypress, castor bean, sunflower, bell pepper, loquat (loquat leaf), betel nut (betel nut), butterbur, coltsfoot (colopodium flower, coltsfoot leaf), grape fruit or fruit peel / seed / leaves, beech, winter licorice, Brazilian licorice, blackberry, plum fruit, blueberry (Vaccinium vitis-idaea), prune, loofah, bell pepper Scarlet japonica (safflower), berry fruits, Bergenia ligulata (root), spinach, Chinese lantern plant (root), linden tree, peony (peony bark), hops, jojoba, maitake mushroom, ephedra, macadamia nuts, mulberry bark (mulberry leaves), marjoram (leaves), mulberry fruit, quince, mango, mangosteen, mandarin fruit, Ganoderma lucidum, Mi Examples include mint, mimosa, Japanese ginger, miracle fruit, soapberry, purple gromwell, purple corn, Melia azadirachta (leaves), lemon balm, melilot, melon fruit, peach leaves, fruit, and seeds, bean sprouts, Morello cherry fruit, molokhia, cornflower, mint, Japanese wormwood, eucalyptus, saxifrage, yuzu fruit, lily, European raspberry, mugwort, lime fruit, rye, raspberry leaves and fruit, lavender, yellow tea, apple fruit, gentian, lemon fruit, lemongrass, forsythia, Chinese milk vetch, rosemary, rosehip, wasabi, and burnet.

[0041] In addition, other beauty ingredients can be added, such as Saccharomyces, hydrolyzed conchiolin, hydrolyzed hyaluronic acid, hydroxypropyltrimonium hyaluronate, and hydrolyzed alkyl (C12-13) glyceryl hyaluronate. These active ingredients can be incorporated into the internal aqueous phase, oil phase, or external aqueous phase by considering their respective characteristics.

[0042] The content of each component in each phase relative to the total amount of the W / O / W emulsion can be appropriately determined depending on the type of active ingredient, surfactant, and the type and amount of solid oil components.

[0043] From the viewpoint of emulsion stability, the weight ratio of the oil phase to the internal aqueous phase is preferably internal aqueous phase / oil phase = 10 / 90 to 90 / 10, more preferably 20 / 80 to 80 / 20, and even more preferably 25 / 75 to 75 / 25. Furthermore, for every 100 parts by weight of the internal aqueous phase, the oil phase is preferably 10 to 500 parts by weight, more preferably 20 to 300 parts by weight, and even more preferably 50 to 200 parts by weight, while the external aqueous phase is preferably 50 to 2000 parts by weight, more preferably 100 to 1500 parts by weight, and even more preferably 200 to 1000 parts by weight.

[0044] The form of the W / O / W type emulsion of the present invention is not particularly limited as long as it has time stability, but for example, the average particle size of the inner aqueous phase droplets may be 0.001 to 100 μm, preferably 0.01 to 100 μm, more preferably 0.1 to 100 μm, and the average particle size of the W / O type emulsion may be, for example, 0.01 to 100 μm, preferably 0.1 to 100 μm, more preferably 0.5 to 100 μm, and even more preferably 1 to 50 μm.

[0045] The viscosity of the W / O / W type emulsion of the present invention is preferably 500 to 50,000 mPa·s, more preferably 1,000 to 40,000 mPa·s, and even more preferably 2,000 to 30,000 mPa·s at 25°C. Here, the viscosity is measured using a BM type viscometer (manufactured by TOKI SANGYO, measurement conditions: rotor No. 4, 12 rpm, 1 minute).

[0046] The W / O / W emulsion of the present invention can be used in a variety of applications where a W / O / W emulsion can be applied. In one embodiment, the W / O / W emulsion of the present invention can be used as a topical preparation (topical composition). In another embodiment, the W / O / W emulsion of the present invention can be used as an oral composition (e.g., food and beverages, oral pharmaceuticals, oral quasi-drugs, etc.). In another embodiment, the W / O / W emulsion of the present invention can be suitably used as a topical preparation.

[0047] Topical preparations are those that can be applied to the surface of the body, such as the skin and mucous membranes, and include, for example, cosmetics, quasi-drugs for topical use, pharmaceuticals for topical use, cleansers, and fragrances. As a topical preparation, for example, a skin preparation is preferred.

[0048] The W / O / W emulsion of the present invention can be suitably used, for example, as a topical skin preparation. In this invention, "topical skin preparation" refers to a dosage form that can be administered to the skin, and includes cosmetics such as creams, serums, lotions, toners, and packs, as well as quasi-drugs, pharmaceuticals, cleansers, and fragrances. The form of the topical skin preparation is not particularly limited, but creams or lotions are preferred. The use of the topical skin preparation of the present invention is not particularly limited as long as it is a known use for which the emulsion can be applied, but cosmetics are preferred, and among these, creams or lotions are even more preferred.

[0049] (Method for producing W / O / W type emulsion) The method for producing the W / O / W type emulsion of the present invention is not particularly limited and can be produced by known methods, but by preparing it by the following method, a W / O / W type emulsion with particularly excellent long-term stability can be obtained.

[0050] For example, the production of a W / O / W type emulsion can be carried out by a step of preparing a W / O type emulsion by mixing an internal aqueous phase containing inositol with an oil phase and emulsifying it, and a step of mixing the prepared W / O type emulsion with an external aqueous phase and emulsifying it. The present invention also includes a method for producing a W / O / W type emulsion, which comprises the steps of preparing the above-mentioned W / O type emulsion and mixing the prepared W / O type emulsion with an external aqueous phase and emulsifying it.

[0051] In the manufacturing method of the present invention, preferred embodiments of the inner aqueous phase, oil phase, and outer aqueous phase are the same as described above. For example, the oil phase preferably contains a solid oily component and a silicone-based surfactant. The outer aqueous phase preferably contains a water-soluble polymer. The production of W / O / W type emulsions preferably involves the following two steps: (1) A step of preparing a W / O type emulsion by mixing an aqueous phase containing inositol with an oil phase containing a solid oily component and a silicone-based surfactant and emulsifying them, (2) This can be carried out by mixing the prepared W / O type emulsion with an external aqueous phase containing a water-soluble polymer and emulsifying it.

[0052] Specifically, an internal aqueous phase containing inositol is added to the oil phase, and the mixture is emulsified at an emulsification temperature of preferably 50-100°C, more preferably 60-95°C, and even more preferably 65-85°C to prepare a W / O type emulsion. At this time, it is preferable to mix the internal aqueous phase and the oil phase in a weight ratio of preferably internal aqueous phase / oil phase = 10 / 90-90 / 10, more preferably 20 / 80-80 / 20, and even more preferably 25 / 75-75 / 25. The internal aqueous phase may contain other optional components (such as metal salts) that may be used as desired. The oil phase usually contains liquid oily components. The oil phase may also contain the optional components mentioned above (such as oil-soluble active ingredients).

[0053] Next, a W / O type emulsion is added to the outer aqueous phase and emulsified at an emulsification temperature preferably 70°C or lower, more preferably 0 to 60°C, and even more preferably 10 to 50°C to prepare a W / O / W type emulsion. The outer aqueous phase may contain an alkyl acrylate methacrylate copolymer. Preferably, the outer aqueous phase does not contain inositol. The amount of each component to be blended is preferably such that its content in the W / O / W type emulsion falls within the range described above.

[0054] In this specification, a numerical range expressed by a lower limit and an upper limit, i.e., "lower limit to upper limit," includes those lower and upper limits. For example, a range expressed as "1 to 2" means 1 or more and 2 or less, including 1 and 2. In this specification, the upper and lower limits may be any combination of ranges. [Examples]

[0055] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0056] <Examples 1-4> A W / O / W emulsion containing inositol was prepared. First, each component was mixed according to the mixing ratio (weight %) shown in Table 1 to prepare the oil phase, internal aqueous phase, and external aqueous phase. Next, the internal aqueous phase was added to the oil phase at a temperature of 80°C and emulsified to prepare a W / O type emulsion. In preparing the W / O type emulsion, the internal aqueous phase and the oil phase were mixed and emulsified. Then, the W / O type emulsion was added to the external aqueous phase at a temperature of 50°C to obtain the W / O / W type emulsions (W / O / W type emulsion formulations) of Examples 1 to 4. More specifically, the W / O type emulsion was obtained by mixing the W / O type emulsion with the external aqueous phase and emulsifying. Visual inspection of the obtained W / O / W type emulsion revealed that it was milky in appearance. Observation of the obtained W / O / W type emulsion with an optical microscope confirmed that a W / O / W type emulsion consisting of an inner aqueous phase, an oil phase, and an outer aqueous phase had been successfully prepared.

[0057] The W / O / W emulsions of Examples 1-3 are W / O / W emulsions containing inositol in the inner aqueous phase. The W / O / W emulsion of Example 4 is a W / O / W emulsion containing inositol in both the inner and outer aqueous phases. The values ​​in Table 1 represent the amount (weight %) of each component in a W / O / W type emulsion (100% weight). For inositol, myo-inositol (manufactured by Tsukuno Rice Fine Chemicals Co., Ltd.) was used.

[0058] <Comparative Example 1> A W / O / W type emulsion (W / O / W type emulsion formulation) was prepared in the same manner as in Example 1, except that the composition of each component was as shown in Table 1. The appearance (visual inspection) of the obtained W / O / W type emulsion was that of a milky liquid.

[0059] <Reference example 1> A W / O / W type emulsion (W / O / W type emulsion preparation) was prepared by the same method as in Example 1, except that the blending of each component was as shown in Table 1. The appearance (visual observation) of the obtained W / O / W type emulsion was milky.

[0060] The W / O / W type emulsion prepared in Comparative Example 1 is a W / O / W type emulsion containing inositol in the external aqueous phase. The W / O / W type emulsion prepared in Reference Example 1 is a W / O / W type emulsion containing no inositol. For Comparative Example 1 and Reference Example 1, it was also confirmed by observation with an optical microscope that W / O / W type emulsions consisting of an internal aqueous phase, an oil phase and an external aqueous phase were successfully prepared.

[0061]

Table 1

[0062] The following components were used in Table 1. Cetyl PEG / PPG-10 / 1 dimethicone: manufactured by Evonik Operations GmbH, HLB 5.0 Squalane: manufactured by Nikko Chemicals Co., Ltd. Microcrystalline wax: manufactured by Nikko Rica Corporation Acrylic acid-alkyl methacrylate copolymer: manufactured by Lubrizol Advanced Materials, Inc. Polyoxyethylene sorbitan monooleate (20 E.O.): manufactured by Kao Corporation

[0063] <Evaluation of W / O / W type emulsion> The stability over time of the W / O / W type emulsions prepared in the Examples, Comparative Examples and Reference Example was evaluated The prepared emulsion preparation was stored under accelerated conditions of 50°C. The appearance of the preparation was visually checked at the time of production (immediately after production), after 1 month of storage and after 2 months of storage, the presence or absence of separation was examined, and evaluation was performed according to the following criteria. The results are shown in Table 2. (Evaluation Criteria) ○: No separation observed △: Slight separation observed ×: Separation is observed

[0064] [Table 2]

[0065] Comparative Example 1, a W / O / W type emulsion containing inositol in the outer aqueous phase, showed separation after one month of storage and exhibited poor stability over time. On the other hand, the W / O / W emulsions of Examples 1-4, which contained inositol in the internal aqueous phase, showed good stability over time. In particular, the W / O / W emulsions of Examples 1-3 exhibited excellent stability over time, with no separation occurring after storage and no change in appearance. The W / O / W emulsion of Example 4 showed improved stability over time compared to Comparative Example 1.

[0066] <Examples 5-6> A W / O / W type emulsion (W / O / W type emulsion formulation) containing inositol in the internal aqueous phase was prepared in the same manner as in Example 1, except that the composition of each component was as shown in Table 3. The appearance (visual inspection) of the obtained W / O / W type emulsion was emulsion-like. The obtained W / O / W type emulsion was observed with an optical microscope to confirm that a W / O / W type emulsion consisting of an internal aqueous phase, an oil phase, and an external aqueous phase had been prepared. The values ​​in Table 3 represent the amount (weight %) of each component in the W / O / W type emulsion (100% by weight). The components used were the same as in Example 1.

[0067] The W / O / W emulsions obtained in Examples 5-6 were stored at room temperature for 6 months and their appearance was visually evaluated. No change in appearance was observed in the W / O / W emulsions obtained in Examples 5-6 over the 6 months, and no separation occurred. The long-term stability of the W / O / W emulsion was confirmed. It was confirmed that the W / O / W emulsion of the present invention is suitably used, for example, as a lotion or cream.

[0068] [Table 3]

[0069] It was found that when inositol is incorporated into a W / O / W type emulsion, incorporating inositol into the internal aqueous phase helps to maintain the stability of the W / O / W emulsion. [Industrial applicability]

[0070] According to the present invention, it is possible to provide a W / O / W type emulsion containing inositol and having good long-term stability, as well as a method for producing the same.

Claims

1. A W / O / W type emulsion comprising an internal aqueous phase, an oil phase, and an external aqueous phase, It contains inositol in the internal aqueous phase, The oil phase contains solid oily components and silicone-based surfactants. The solid oily component is wax. A W / O / W type emulsion with an inositol content of 0.01 to 0.5% by weight.

2. The W / O / W emulsion according to claim 1, wherein the outer aqueous phase does not contain inositol.

3. The W / O / W type emulsion according to claim 1 or 2, wherein the outer aqueous phase contains a water-soluble polymer.

4. The W / O / W type emulsion according to claim 1 or 2, wherein the HLB value of the silicone-based surfactant is 7 or less.

5. The W / O / W emulsion according to claim 1 or 2, wherein the silicone-based surfactant is a silicone-based surfactant having a polyether group and an alkyl group.

6. The W / O / W emulsion according to claim 5, wherein the silicone-based surfactant having a polyether group and an alkyl group is cetyl PEG / PPG-10 / 1 dimethicone or lauryl PEG-9 polydimethylsiloxyethyl dimethicone.

7. The W / O / W type emulsion according to claim 1 or 2, wherein the content of the solid oily component is 0.5% by weight or more.

8. The W / O / W emulsion according to claim 1 or 2, wherein the oil phase contains at least one liquid oily component selected from the group consisting of hydrocarbon oils, natural animal and vegetable oils and fats, ester oils, silicone oils, higher alcohols and higher fatty acids.

9. The W / O / W emulsion according to claim 1 or 2, wherein the oil phase contains a hydrocarbon oil.

10. The W / O / W emulsion according to claim 3, wherein the water-soluble polymer is an alkyl acrylate methacrylate copolymer.

11. The W / O / W type emulsion according to claim 1 or 2, further comprising a metal salt in the internal aqueous phase.

12. The W / O / W type emulsion according to claim 1 or 2, wherein the weight ratio of the internal aqueous phase to the oil phase is internal aqueous phase / oil phase = 10 / 90 to 90 / 10.

13. A W / O / W type emulsion according to claim 1 or 2, which is a topical preparation.

14. A W / O / W type emulsion according to claim 1 or 2, which is a topical skin preparation.

15. A W / O / W type emulsion according to claim 1 or 2, which is a cream or lotion.

16. The process involves preparing a W / O type emulsion by mixing an internal aqueous phase containing inositol with an oil phase and emulsifying them, and then mixing the prepared W / O type emulsion with an external aqueous phase and emulsifying it. A method for producing a W / O / W emulsion, comprising: including and incorporating an amount of inositol such that the inositol content in the resulting W / O / W emulsion is 0.01 to 0.5% by weight.

17. The manufacturing method according to claim 16, wherein the outer aqueous phase does not contain inositol.

18. The oil phase contains solid oily components and silicone-based surfactants. The manufacturing method according to claim 16 or 17, wherein the outer aqueous phase contains a water-soluble polymer.

19. The manufacturing method according to claim 16 or 17, wherein the internal aqueous phase and the oil phase are mixed in a weight ratio of internal aqueous phase / oil phase = 10 / 90 to 90 / 10.

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