Emulsion composition

Abstract

The object of the present invention is to provide an emulsifying composition that contains 2% by weight or more of ceramide while exhibiting excellent softness, solubility, and emulsification stability. [Solution] An emulsifying composition comprising (A) 2% by weight or more of ceramide, (B) higher alcohol, (C) higher fatty acid, and (D) phospholipid can exhibit excellent softness, solubility, and emulsification stability.

Description

Technical Field

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[0001] The present invention relates to an emulsified composition that can exhibit softness, solubility, and emulsion stability while containing 2% by weight or more of ceramide.

Background Art

[0002] The skin covers the outermost layer of the living body, forms a boundary with the external world, and has an essential barrier function for maintaining life, such as preventing the intrusion of external substances and preventing the loss of internal components including moisture. Between keratinocytes, lipids mainly composed of ceramide form a lamellar structure and play an important role in exerting the barrier function. <000001~0>

[0003] When ceramide decreases due to internal or external factors such as aging and ultraviolet exposure, the barrier function deteriorates, leading to the progression of skin aging such as wrinkles and skin dryness, or the induction of skin disorders such as atopic dermatitis, ichthyosis, acne, skin immune abnormalities, and skin infections.

[0004] For skin with reduced ceramide, it is effective to replenish ceramide from the outside. Conventionally, external emulsified compositions in which ceramide is emulsified have been developed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] To effectively replenish ceramides in the skin, it is effective to use an emulsified composition containing a high concentration of ceramides. However, conventionally, when emulsified compositions contain ceramides at a high concentration of 2% by weight or more, the emulsification stability tends to be impaired. Furthermore, considering the application of ceramide-rich topical preparations to sensitive skin, there is room for improvement in the softness of the emulsified composition itself.

[0007] The object of the present invention is to provide an emulsifying composition that contains 2% by weight or more of ceramide while exhibiting excellent softness, solubility, and emulsification stability. [Means for solving the problem]

[0008] The inventors, through diligent research, discovered that by preparing an emulsion composition by combining 2% by weight or more of ceramide with higher alcohols, higher fatty acids, and phospholipids, the emulsion composition can be given excellent softness, solubility, and emulsion stability. The present invention was completed by further research based on this finding.

[0009] In other words, the present invention provides inventions in the following embodiments. Item 1. An emulsified composition comprising (A) 2% by weight or more of ceramide, (B) higher alcohol, (C) higher fatty acid, and (D) phospholipid. Item 2. The emulsified composition according to Item 1, wherein the (D) component is hydrogenated lecithin. Item 3. The emulsifying composition according to item 1 or 2, wherein the (B) component is a higher alcohol having 10 to 24 carbon atoms. Item 4. The emulsifying composition according to items 1 to 3, wherein the (C) component is a higher fatty acid having 10 to 24 carbon atoms. Item 5. An emulsifying composition according to any one of items 1 to 4, further comprising (E) a nonionic surfactant. Item 6. The emulsified composition according to any one of items 1 to 5, wherein the content of component (C) per 1 part by weight of component (B) is 0.03 to 0.3 parts by weight. [Effects of the Invention]

[0010] According to the present invention, a formulation of an emulsified composition is provided that contains 2% by weight or more of ceramide while exhibiting excellent softness, solubility, and emulsification stability. [Modes for carrying out the invention]

[0011] The emulsifying composition of the present invention is characterized by containing 2% by weight or more of ceramide (hereinafter also referred to as "component (A)"), a higher alcohol (hereinafter also referred to as "component (B)"), a higher fatty acid (hereinafter also referred to as "component (C)"), and a phospholipid (hereinafter also referred to as "component (D)"). The emulsifying composition of the present invention will be described in detail below.

[0012] [(A) Ceramide] The emulsifying composition of the present invention contains 2% by weight or more of ceramide as component (A). In the emulsifying composition of the present invention, ceramide is contained in the oil phase. Despite the high concentration of ceramide, the emulsifying composition of the present invention exhibits excellent softness, solubility, and emulsification stability.

[0013] The type of ceramide used in the present invention is not particularly limited, but examples include ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6I, ceramide 6II, ceramide 7, ceramide 8, ceramide 9, ceramide 10, etc. These ceramides may be used individually or in combination of two or more. Among these ceramides, ceramide 1, ceramide 2, ceramide 3, and more preferably ceramide 2 are preferred from the viewpoint of further improving the softness, solubility, and / or emulsion stability of the emulsion composition.

[0014] The origin of the ceramide used in this invention is not particularly limited and may be appropriately determined depending on the type of ceramide, for example, it may be extracted from plants or animals, obtained by microbial fermentation, or chemically synthesized.

[0015] In the emulsified composition of the present invention, the concentration of component (A) may be 2% by weight or more, regardless of whether it is an oil-in-water type or water-in-oil type, but is preferably 2 to 10% by weight, more preferably 3 to 8% by weight, even more preferably 2 to 8% by weight, and even more preferably 3 to 5% by weight.

[0016] [(B) Higher alcohols] The emulsifying composition of the present invention contains a higher alcohol as component (B). In the emulsifying composition of the present invention, the higher alcohol is included in the oil phase.

[0017] The higher alcohol used in this invention may be any pharmaceutically or cosmetically acceptable monohydric alcohol having 6 or more carbon atoms, for example, a monohydric alcohol having 10 to 24 carbon atoms, preferably a monohydric alcohol having 14 to 22 carbon atoms, and more preferably a monohydric alcohol having 16 to 18 carbon atoms.

[0018] The carbon chain of the higher alcohol used in this invention may be either linear or branched. If the higher alcohol is branched, the branching shape is not particularly limited, but isotype is preferred. Furthermore, the carbon chain of the higher alcohol used in this invention may be either saturated or unsaturated, but saturated type is preferred.

[0019] Examples of higher alcohols used in the present invention include linear higher alcohols such as caprin alcohol, lauryl alcohol, myristyl alcohol, cetanol, stearyl alcohol, oleyl alcohol, linoleyl alcohol, arachidyl alcohol, behenyl alcohol, and linoglyceryl alcohol; and branched higher alcohols such as isostearyl alcohol and 2-octyldodecanol. These higher alcohols may be used individually or in combination of two or more.

[0020] As the component (B) used in the present invention, from the viewpoint of further improving the softness, solubility, and / or emulsion stability of the emulsion composition, it is preferably contained at least a linear higher alcohol, more preferably a combination of a linear higher alcohol and a branched higher alcohol, still more preferably a combination of a linear alcohol having 10 to 24 carbon atoms and a branched alcohol having 10 to 24 carbon atoms, even more preferably a combination of a linear alcohol having 14 to 22 carbon atoms and a branched alcohol having 14 to 22 carbon atoms, still even more preferably a combination of a linear alcohol having 16 to 18 carbon atoms and a branched alcohol having 16 to 18 carbon atoms, and particularly preferably a combination of stearyl alcohol and isostearyl alcohol.

[0021] When a linear higher fatty acid and a branched higher fatty acid are used in combination as the component (B), the ratio between the two is not particularly limited. For example, per 100 parts by weight of the linear higher alcohol, the branched higher alcohol is 1 to 100 parts by weight, preferably 2 to 80 parts by weight, more preferably 3 to 50 parts by weight, and even more preferably 5 to 40 parts by weight.

[0022] The concentration of the component (B) in the emulsion composition of the present invention may be appropriately set according to the type of higher alcohol used and the form of emulsification. For example, regardless of whether it is a water-in-oil type or an oil-in-water type, it is 2 to 18% by weight, 2.5 to 10% by weight, or 3 to 6% by weight.

[0023] In the emulsion composition of the present invention, the ratio of the component (A) to the component (B) is determined according to the concentrations of the above-mentioned respective components. Specifically, regardless of whether it is a water-in-oil type or an oil-in-water type, per 1 part by weight of the component (A), the component (B) is 0.3 to 6.25 parts by weight, preferably 0.5 to 6.25 parts by weight, more preferably 1 to 6 parts by weight, and even more preferably 1 to 1.8 parts by weight.

[0024] [(C) Higher fatty acid] The emulsion composition of the present invention contains a higher fatty acid as the component (C). In the emulsion composition of the present invention, the higher fatty acid is contained in the oil phase.

[0025] The higher fatty acids used in this invention may be any pharmaceutically or cosmetically acceptable fatty acids with 6 or more carbon atoms, but examples include fatty acids with 10 to 24 carbon atoms, preferably fatty acids with 12 to 22 carbon atoms, and more preferably fatty acids with 17 to 22 carbon atoms.

[0026] Furthermore, the carbon chain of the higher fatty acid used in this invention may be linear or branched, and may be saturated or unsaturated.

[0027] Examples of higher fatty acids used in the present invention include saturated higher fatty acids such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid; and unsaturated higher fatty acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid. These higher alcohols may be used individually or in combination of two or more.

[0028] Among these higher fatty acids, from the viewpoint of further improving the softness, solubility, and / or emulsification stability of the emulsified composition, linear and / or saturated fatty acids are preferred, more preferably linear saturated fatty acids, even more preferably linear saturated fatty acids having 12 to 22 carbon atoms, even more preferably linear saturated fatty acids having 17 to 22 carbon atoms, and particularly preferably stearic acid.

[0029] The concentration of component (C) in the emulsified composition of the present invention can be appropriately set according to the type of higher fatty acid used, the form of emulsification, etc., but for example, in the case of an oil-in-water type, it can be 0.1 to 5% by weight, preferably 0.2 to 4% by weight, and more preferably 0.25 to 2.5% by weight, and in the case of a water-in-oil type, it can be 0.5 to 10% by weight, preferably 0.5 to 8% by weight, and more preferably 0.5 to 5% by weight.

[0030] In the emulsified composition of the present invention, the ratio of component (A) to component (C) is determined according to the concentration of each component as described above. Specifically, in the case of an oil-in-water type, component (C) is 0.025 to 2.5 parts by weight, preferably 0.05 to 2 parts by weight, and more preferably 0.1 to 1 part by weight, per 1 part by weight of component (A). In the case of a water-in-oil type, component (C) is 0.025 to 5 parts by weight, preferably 0.05 to 3 parts by weight, and more preferably 0.1 to 2 parts by weight, per 1 part by weight of component (A).

[0031] In the emulsified composition of the present invention, the ratio of component (B) to component (C) is determined according to the concentration of each component as described above. However, from the viewpoint of further improving the softness, solubility, and / or emulsification stability of the emulsified composition, the content of component (C) per 1 part by weight of component (B) is preferably 0.03 to 0.32 parts by weight, more preferably 0.05 to 0.24 parts by weight, and even more preferably 0.07 to 0.19 parts by weight.

[0032] [(D) Phospholipids] The emulsifying composition of the present invention contains a phospholipid as component (D). In the emulsifying composition of the present invention, the phospholipid is contained in the aqueous phase.

[0033] While there are no particular limitations on phospholipids, glycerophospholipids are preferred. Glycerophospholipids are substances having a glycerophosphate skeleton and possessing lipophilic groups such as fatty acid esters, long-chain alkyl ethers, and vinyl ethers. Specific examples of glycerophospholipids include phosphatidylcholine (lecithin such as soy lecithin and egg yolk lecithin), phosphatidylethanolamine, phosphatidylserine, phosphadylinositol, phosphatidylinositol polyphosphate, diphosphatidylglycerol (cardiolipin), phosphatidic acid, and their hydrogenated, hydroxylated, and hydrolyzed products. These phospholipids may be used individually or in combination of two or more.

[0034] Among these phospholipids, lecithin, hydrogenated lecithin, and hydroxylated lecithin are preferred from the viewpoint of further improving the softness, solubility, and / or emulsification stability of the emulsified composition, and hydrogenated lecithin is more preferred.

[0035] In the emulsified composition of the present invention, the ratio of component (A) to component (D) is determined according to the concentration of each component as described above. Specifically, regardless of whether it is an oil-in-water type or a water-in-oil type, component (D) is 0.003 to 0.1 parts by weight per 1 part by weight of component (A), preferably 0.005 to 0.07 parts by weight, and more preferably 0.008 to 0.05 parts by weight.

[0036] [(E) Nonionic surfactants] The emulsifying composition of the present invention may contain a nonionic surfactant as component (E). The emulsifying composition of the present invention exhibits excellent softness, solubility, and emulsification stability even with a high concentration of ceramide. Therefore, ceramide soluble in a high concentration in the emulsifying composition can be applied via the skin-friendly emulsifying composition, thereby enabling highly efficient replenishment of ceramide. Thus, the excellent physical properties of the emulsifying composition of the present invention make it possible to efficiently enjoy the benefits of high-concentration ceramide (improvement effects against dryness and itchiness, etc.) through highly efficient replenishment of ceramide. For this reason, even if the emulsifying composition of the present invention further contains another surfactant in addition to component (D) above, which generally adds skin irritation, it can effectively exhibit the benefits of high-concentration ceramide (improvement effects against dryness and itchiness, etc.). From this viewpoint, a preferred embodiment of the emulsifying composition of the present invention is the case in which a nonionic surfactant is included as component (E).

[0037] The nonionic surfactant used in the present invention is not particularly limited as long as it is a nonionic surfactant other than component (D) above, but examples include glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and the like.

[0038] Polyglycerol fatty acid esters are esters of fatty acids and polyglycerol. In polyglycerol fatty acid esters, the number of ester bonds (the number of fatty acids bonded per polyglycerol molecule) can be, for example, 1 to 10. The number of carbon atoms in the fatty acids constituting the polyglycerol fatty acid ester can be, for example, 6 to 24. Furthermore, the degree of polymerization of the polyglycerol constituting the polyglycerol fatty acid ester can be, for example, 2 to 10, preferably 4 to 10, and more preferably 6 to 10. Specifically, as polyglycerin fatty acid esters, these include polyglyceryl-2 laurate (diglyceryl laurate), polyglyceryl-5 laurate (pentaglyceryl laurate), polyglyceryl-6 laurate (hexaglyceryl laurate), polyglyceryl-10 laurate (decaglyceryl laurate), polyglyceryl-2 stearate (diglyceryl monostearate), polyglyceryl-2 oleate (diglyceryl monooleate), polyglyceryl-4 oleate (tetraglyceryl monooleate), polyglyceryl-10 oleate (decaglyceryl monooleate), polyglyceryl-5 trioleate (pentaglyceryl trioleate), and trio Examples include polyglyceryl-10 leate (decaglyceryl trioleate), polyglyceryl-10 palmitate (decaglyceryl monopalmitate), polyglyceryl-10 myristate, polyglyceryl-2 isostearate, polyglyceryl-10 isostearate, polyglyceryl-2 triisostearate, polyglyceryl-4 stearate, polyglyceryl-6 tristearate, polyglyceryl-10 pentastearate, polyglyceryl-10 pentahydroxystearate, polyglyceryl-10 pentaoleate, polyglyceryl-6 polyricinoleate, and polyglyceryl-10 polyricinoleate.

[0039] Examples of HLB values ​​for nonionic surfactants include 6 to 17, preferably 12 to 17, and more preferably 14 to 16.

[0040] These nonionic surfactants may be used individually or in combination of two or more.

[0041] Among these nonionic surfactants, polyglycerin fatty acid esters are preferred, more preferably polyglycerin fatty acid esters having a degree of polymerization of 4 to 10 (more preferably 6 to 10), a number of ester bonds preferably 1 to 5 (more preferably 1 to 2), and a number of carbon atoms in the fatty acids constituting the polyglycerin fatty acid ester preferably 8 to 22 (more preferably 10 to 14), even more preferably polyglyceryl-6 laurate (hexaglyceryl laurate) and polyglyceryl-10 laurate (decaglyceryl laurate), and particularly preferably polyglyceryl-10 laurate (decaglyceryl laurate).

[0042] When the emulsified composition of the present invention contains component (E), the amount of component (E) is not particularly limited, but for example, it may be 0.2 to 4% by weight, preferably 0.5 to 3.5% by weight, and more preferably 0.7 to 0.3% by weight.

[0043] [Liquid oil] The emulsified composition of the present invention may further contain, in addition to the above components, liquid oil (oil that does not fall under component (B) or (C) above) in the oil phase. Liquid oil is oil that maintains a liquid form at 25°C.

[0044] Examples of liquid oils used in the present invention (other than components (B) and (C) above) include ester oils, vegetable oils, hydrocarbon oils, and silicone oils.

[0045] Specifically, the ester oils include isopropyl myristate, octyldodecyl myristate, octyldodecyl oleate, dipentaerythritol fatty acid ester, isopropyl adipate, isobutyl adipate, isopropyl sebacate, cetyl ethylhexanoate, palmityl ethylhexanoate, myristyl myristate, isopropyl palmitate, cetyl palmitate, ethyl oleate, batyl stearate, hexyldecyl isostearate, isopropyl linoleate, cetyl octanoate, butyl stearate, and ethyl lauryl , hexyl laurate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, lanolin acetate, isocetyl stearate, isocetyl isostearate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, alkyl benzoate (C12-C15), castor oil fatty acid methyl ester, oleyl oleate, 2-heptyl undecyl palmitate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, etc., in which one molecule of fatty acid is bonded to one molecule of monohydric or polyhydric alcohol. Diester oils; diester oils in which two molecules of fatty acids such as propylene glycol dicaprylate, neopentyl glycol dioctanoate, neopentyl glycol diethylhexanoate, glycol diethylhexanoate, neopentyl glycol dicaprate, glycerin diheptylundecanoate, and di(caprylic / capric acid)butylene glycol are bonded to one molecule of polyhydric alcohol; triethylhexanoin (glyceryl triethylhexanoate), diglyceryl triisostearate, tri(caprylic / capric acid)glyceryl, and glyceryl triisopalmitate. Triesters in which three fatty acid molecules such as ceryl, glyceryl triisooctanoate, trimethylolpropane triethylhexanoate, trimethylolpropane triisostearate, trimethylolpropane triisostearate, glyceryl triisostearate, glyceryl trimyristate, and glyceride tri-2-heptylundecanoate are bonded to one polyhydric alcohol molecule with a valency of 3 or higher; Tetraester oils in which four fatty acid molecules such as pentaerythrityl tetraethylhexanoate and pentaerythrityl tetraoctanoate are bonded to one polyhydric alcohol molecule with a valency of 4 or higher;Examples include diester oils in which two molecules of monohydric alcohol are bonded to one molecule of dicarboxylic acid, such as diethyl sebacate, diisopropyl sebacate, di2-ethylhexyl sebacate, diisostearyl malate, diethylhexyl naphthalene dicarboxylate, di2-hexyldecyl adipate, di2-heptylundecyl adipate, and di2-ethylhexyl succinate; and fatty acid cholesteryls such as lanolin fatty acid cholesteryl, hydroxystearate cholesteryl, and macadamia nut fatty acid cholesteryl.

[0046] These liquid oils may be used individually or in combination of two or more types.

[0047] Among these liquid oils, ester oils are preferred, more preferably monoester oils in which one fatty acid molecule is bonded to one monohydric or polyhydric alcohol molecule, triester oils in which three fatty acid molecules are bonded to one trihydric or higher polyhydric alcohol molecule, and particularly preferred are octyldodecyl myristate and triethylhexanoin.

[0048] When the emulsified composition of the present invention contains liquid oil (other than components (B) and (C) above), the concentration is not particularly limited and can be set appropriately depending on the type of liquid oil used, the emulsification form, etc. For example, in the case of an oil-in-water type, the liquid oil may be 1 to 25% by weight, preferably 3 to 20% by weight, and more preferably 5 to 15% by weight in total. In the case of a water-in-oil type, the liquid oil may be 10 to 70% by weight, preferably 12 to 50% by weight, and more preferably 15 to 30% by weight.

[0049] [Polyhydric alcohols] The emulsifying composition of the present invention may optionally contain a polyhydric alcohol. In the emulsifying composition of the present invention, the polyhydric alcohol is contained in the aqueous phase.

[0050] The polyhydric alcohol is not particularly limited as long as it is pharmaceutically or cosmetically acceptable, but examples include ethylene glycol, 1,3-butylene glycol, propylene glycol, isoprene glycol, diethylene glycol, dipropylene glycol, polypropylene glycol, glycerin, and the like.

[0051] These polyhydric alcohols may be used individually or in combination of two or more.

[0052] Among these polyhydric alcohols, 1,3-butylene glycol and glycerin are preferred.

[0053] When the emulsifying composition of the present invention contains a polyhydric alcohol, its concentration is not particularly limited, but for example, in the case of an oil-in-water type, it can be 1 to 40% by weight, preferably 3 to 20% by weight, and more preferably 5 to 15% by weight, and in the case of a water-in-oil type, it can be 1 to 50% by weight, preferably 5 to 30% by weight, and more preferably 10 to 25% by weight.

[0054] [Thickener] In addition to the components described above, the emulsifying composition of the present invention may contain a thickening agent as needed for adjusting viscosity, etc. In the emulsifying composition of the present invention, the thickening agent is contained in the aqueous phase.

[0055] The thickening agent is not particularly limited as long as it is pharmaceutically or cosmetically acceptable, but examples include xanthan gum, guar gum, locust bean gum, carrageenan, dextran, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, sodium alginate, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, carboxyvinyl polymer, alkyl methacrylate copolymer, sodium polyacrylate bentonite, dextrin fatty acid ester, pectin, and dextrin palmitate. Among these thickening agents, xanthan gum, carboxyvinyl polymer, and alkyl methacrylate copolymer are preferred.

[0056] These thickening agents may be used individually or in combination of two or more.

[0057] When a thickening agent is included in the emulsified composition of the present invention, there are no particular limitations on its concentration, but for example, regardless of whether it is an oil-in-water type or water-in-oil type, a concentration of 0.01 to 2% by weight, preferably 0.02 to 1% by weight, and more preferably 0.05 to 0.4% by weight is given.

[0058] [Other surfactants] The emulsifying composition of the present invention may optionally contain surfactants other than the above components (D) and (E). Specific examples of such surfactants include anionic surfactants (including non-amino acid-based and amino acid-based anionic surfactants), cationic surfactants, and amphoteric surfactants.

[0059] On the other hand, because the emulsifying composition of the present invention is excellent in softness, solubility, and emulsification stability, these properties can be effectively exhibited even when it contains only trace amounts or no surfactants other than the above-mentioned components (D) and (E). Therefore, in a further preferred example of the emulsifying composition of the present invention, the content of surfactants other than the above-mentioned components (D) and (E) is, for example, 0.5% by weight or less, preferably 0.3% by weight or less, more preferably 0.2% by weight or less, and even more preferably 0% by weight.

[0060] [water] The emulsifying composition of the present invention contains water in order to form an aqueous phase in an emulsified state.

[0061] The water content in the emulsified composition of the present invention can be appropriately set depending on the emulsification form, but for example, in the case of an oil-in-water type, it can be 30 to 90% by weight, preferably 35 to 80% by weight, and more preferably 45 to 70% by weight, and in the case of a water-in-oil type, it can be 10 to 70% by weight, preferably 30 to 70% by weight, and more preferably 40 to 60% by weight.

[0062] [Other ingredients] In addition to the components described above, the emulsified composition of the present invention may optionally contain pharmacoactive ingredients that can exert pharmaceutical or cosmetic physiological functions. Examples of such pharmacoactive ingredients include steroids, antihistamines, local anesthetics, anti-inflammatory agents, bactericides, antipruritics, skin protectants, blood circulation promoting ingredients, vitamins, mucopolysaccharides, and the like. These pharmacoactive ingredients may be used individually or in combination of two or more. Furthermore, when these pharmacoactive ingredients are included in the emulsified composition of the present invention, their concentrations may be appropriately set according to the type of pharmacoactive ingredient used, the expected effect, etc.

[0063] Furthermore, in addition to the components described above, the emulsified composition of the present invention may contain other additives commonly used in topical preparations, as needed. Examples of such additives include buffers, solubilizers, chelating agents, preservatives, antioxidants, stabilizers, fragrances, colorants, and the like. When these additives are included in the emulsified composition of the present invention, their content may be appropriately determined depending on the type of additive used.

[0064] [Formulation form and use] The emulsified composition of the present invention may be in either an oil-in-water or water-in-oil emulsion form, but the oil-in-water form is preferred.

[0065] The formulation form of the emulsified composition of the present invention is not particularly limited, and examples include emulsion (emulsified lotion, etc.) and cream.

[0066] The emulsified composition of the present invention is suitably used as a topical preparation, preferably a topical preparation applied transdermally. Specific examples of the emulsified composition of the present invention include topical pharmaceuticals, topical quasi-drugs, cosmetics, and skin cleansers. Among these formulations, topical pharmaceuticals and topical quasi-drugs are preferred.

[0067] The emulsifying composition of the present invention, while containing a high concentration of ceramide, exhibits excellent softness, solubility, and emulsification stability. Therefore, ceramide dissolved in a high concentration within the emulsifying composition can be applied via the skin-friendly emulsifying composition, thereby enabling highly efficient ceramide replenishment. Thus, the superior physical properties of the emulsifying composition of the present invention make it possible to efficiently enjoy the benefits of high-concentration ceramide through highly efficient ceramide replenishment.

[0068] Therefore, the emulsified composition of the present invention can be specifically used for purposes such as moisturizing the skin, improving wrinkles, improving or normalizing the skin's barrier function, preventing skin aging, improving rough skin, and relieving itching.

[0069] [Manufacturing method] The emulsified composition of the present invention can be manufactured according to known methods for manufacturing emulsified formulations. For example, the following method can be used to manufacture the emulsified composition of the present invention. First, an oil phase composition is prepared by mixing component (A), component (B), component (C), and other oily components added as needed. Separately, an aqueous phase composition is prepared by mixing water and other water-soluble components added as needed. Component (D) and component (E), which may be added as needed, may be incorporated into either the aqueous phase composition or the oil phase composition, or both. However, in the case of an oil-in-water emulsion, it is preferable to incorporate component (D) into the aqueous phase composition and component (E) into the oil phase composition. Next, the obtained aqueous phase composition and oil phase composition are mixed and emulsified using an emulsification method such as a homogenizer to obtain the emulsified composition of the present invention. [Examples]

[0070] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0071] Test example An emulsified composition (oil-in-water type) with the composition shown in Table 1 was prepared by the following procedure. First, the oil phase composition was prepared by mixing the oil phase components shown in Tables 1 and 2 and heating and dissolving them at 85°C. Separately, the aqueous phase composition was prepared by mixing the aqueous phase components shown in Tables 1 and 2 and heating and dissolving them at 85°C. The oil phase composition, heated at 85°C, was gradually added to the aqueous phase composition, heated at 85°C, and the particles (oil droplets) were refined using a homomixer. The mixture was then cooled to 35°C while stirring to obtain an oil-in-water type emulsified composition.

[0072] For each of the resulting emulsified compositions, the moisturizing effect, softness, solubility, and emulsification stability were evaluated using the following method.

[0073] (1) Moisturizing effect Five panelists with sensitive skin who experience rough skin evaluated the moisturizing effect of each emulsified composition. Specifically, 0.5g of each emulsified composition was applied to the entire face, and the moisturizing effect was evaluated. The moisturizing effect was evaluated on a 5-point scale from 1 to 5, with "Good" being 5 points, "Good" being 4 points, "Neither good nor bad" being 3 points, "Poor" being 2 points, and "Poor" being 1 point. The sum of the scores obtained from the five participants was classified according to the following criteria to determine the moisturizing effect evaluation results. The results are shown in Tables 1 and 2. ◎: More than 20 and less than 25 ○: More than 15 but less than 20 △: More than 10 and less than 15 ×: 10 or less

[0074] (2) Softness (feel) The same five panelists as in (1) above evaluated the softness of each emulsion composition. Specifically, 0.5g of each emulsion composition was applied to the entire face, and its softness was evaluated. The softness was evaluated using a 5-point scale, where "extremely soft" was 5 points and "not soft" was 1 point, based on the "evaluation of the softness felt on the skin when applied." The sum of the scores from the five panelists was classified according to the following criteria to determine the softness evaluation results. The results are shown in Table 1. The sum of the scores from the five panelists was classified according to the following criteria to determine the softness evaluation results. The results are shown in Tables 1 and 2. ◎: More than 20 and less than 25 ○: More than 15 but less than 20 △: More than 10 and less than 15 ×: 10 or less

[0075] (3) Soluble Under conditions of 15°C, the emulsified composition was filled into glass vials (No. 8 vials), and the presence or absence of insoluble matter was checked visually. The results are shown in Tables 1 and 2. ○: No insoluble matter ×: Contains insoluble matter.

[0076] (4) Emulsion stability The emulsified composition was filled into glass vials (No. 8 vials) and stored at 40°C for 90 days. After storage, the emulsified composition was visually inspected to check for separation, and further, any changes in the feel of use, as evaluated in (2) above, were checked. The results are shown in Tables 1 and 2. ○: No separation or change in feel. ×: At least one of the following has occurred: separation or change in feel.

[0077] [Table 1]

[0078] [Table 2]

[0079] The emulsified composition containing 2% by weight or more of ceramide contains higher alcohols, higher fatty acids, and phospholipids. If any one of the qualities is lacking (Comparative Examples 1-4), moisturizing effect, softness, solubility, and milkiness are affected. Although it was not entirely satisfactory in terms of chemical stability, higher alcohols, higher fatty acids, And when phospholipids are included (Examples 1-6), moisturizing effect, softness, solubility, and emulsification are observed. It was excellent in all aspects of stability. Also, among the panelists with sensitive skin, itching caused by skin irritation... In panelists who possessed the characteristic, an improvement in itching was also observed with the emulsified compositions of Comparative Examples 1 to 6.

[0080] Prescription examples Emulsified compositions (oil-in-water type) with the formulations shown in Table 3 were prepared in the same manner as the test examples. All of the resulting emulsion compositions exhibited excellent moisturizing effect, softness, solubility, and emulsion stability, similar to the examples in the test cases.

[0081] [Table 3]

Claims

[Claim 1] (A) Ceramide 2% by weight or more, (B) Higher alcohols, (C) Higher fatty acids, and (D) An emulsified composition containing phospholipids.

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