O / w / o / w emulsion cosmetic preparation

Abstract

This O / W / O / W emulsion cosmetic preparation is obtained by dispersing, in an external aqueous phase containing a water-soluble polymer, an O / W / O emulsion that includes: as a dispersion phase, an O / W emulsion obtained by dispersing an internal oil phase containing a polar component (A) in an aqueous phase; and, as a continuous phase, an oil phase containing dipentaerythrityl tri-polyhydroxystearate (B) but not containing the polar component (A). Specific examples of the polar component (A) include oil-soluble vitamins, carotenoids, essential oils, and oil-soluble ultraviolet absorbers. Specific examples of the water-soluble polymer include carbomers, alkyl-modified carboxyvinyl polymers, 2-acrylamido-2-methylpropane sulfonic acid-based water-soluble polymers, hydrophobically modified polyether urethanes, and hydrophobically modified alkyl celluloses.

Description

O / W / O / W type emulsified cosmetic

[0001] The present invention relates to an O / W / O / W type emulsified cosmetic in which an O / W / O type emulsion, which is obtained by dispersing an O / W type emulsion in an oil phase, is dispersed in an aqueous phase. More specifically, the present invention relates to an O / W / O / W type emulsified cosmetic with good temporal stability.

[0002] Conventionally, oil-in-water (O / W) and water-in-oil (W / O) emulsions have been widely used as emulsified cosmetics. However, W / O / W emulsions, which are composite emulsions of oil-in-water and water-in-oil, have several advantages. For example, because the outermost phase is the aqueous phase, they have a refreshing feel, and the aqueous phase can be separated into an inner aqueous phase and an outer aqueous phase. This allows for the separation of components that would become unstable due to contact with each other if mixed in the same aqueous phase, into the inner and outer aqueous phases. It also allows for the dissolution of components that are difficult to dissolve in the outer aqueous phase, which requires a neutral pH, by making the pH of the inner aqueous phase acidic or alkaline. However, W / O / W emulsions generally have poor stability over time, and it is currently difficult to obtain a W / O / W composite emulsion that is stable enough for practical use.

[0003] Regarding such W / O / W type emulsified cosmetics, for example, Patent Document 1 discloses a W / O type emulsified cosmetic comprising a W / O type emulsion containing an emulsifier with an HLB of 7 or less and an electrolyte dispersed in an outer aqueous phase (see Claim 1), and it is stated that this W / O / W type emulsified cosmetic has excellent feel and good stability over time (see Paragraph 0001). In this invention, it is essential that the W / O type emulsion contains an emulsifier with an HLB of 7 or less, and it is stated that polyhydroxystearyl alkylenated glycol (for example, polyethylene glycol dipolyhydroxystearate), which is a polyhydroxystearate ester of a polyhydric alcohol, is preferably used as such an emulsifier (see Paragraph 0034), and polyethylene glycol dipolyhydroxystearate is incorporated in all examples of Patent Document 1. However, experiments conducted by the inventors revealed that even when polyethylene glycol dipolyhydroxystearate is used in the preparation of W / O type emulsions, a sufficiently stable W / O / W type emulsified cosmetic composition is not always obtained (see Reference Example 2 below).

[0004] On the other hand, Patent Document 2 discloses a water-in-oil type emulsified cosmetic containing a nonionic surfactant, a volatile silicone, purified water, and dipentaerythrityl tripolyhydroxystearate (see Claim 1), and it is disclosed that this W / O type emulsified cosmetic is excellent in moisture retention and storage stability (see Paragraph 0001). Although Patent Document 2 does not have a description explicitly stating the purpose of blending dipentaerythrityl tripolyhydroxystearate, when comparing Examples 1 to 4 with Comparative Examples 1 to 4, it is shown that the moisture retention stability and storage stability of the W / O type emulsified cosmetic are significantly improved by blending dipentaerythrityl tripolyhydroxystearate (see Paragraph 0028). Therefore, it is presumed that dipentaerythrityl tripolyhydroxystearate is blended to improve moisture retention stability and storage stability. In this invention, a nonionic surfactant is used in the preparation of the W / O type emulsion, and nothing is disclosed regarding whether a stable W / O type emulsion can be obtained when dipentaerythrityl tripolyhydroxystearate is blended in the oil phase in the absence of a nonionic surfactant.

[0005] JP-A-2002-275029 JP-A-2008-174514

[0006] The present invention has been completed under such background art, and an object thereof is to provide a novel O / W / O / W type emulsified cosmetic that maintains the characteristics of a W / O / W type emulsified cosmetic and improves its weak point, i.e., stability over time.

[0007] The inventors of the present invention conducted diligent studies to solve these problems and found that in a W / O / W type emulsified cosmetic composition in which a W / O type emulsion is dispersed in an outer aqueous phase, if dipentaerythrityl tripolyhydroxystearate is included in the oil phase as an emulsifier for the W / O type emulsion, and a water-soluble polymer is included in the outer aqueous phase, the dispersion state of the droplets consisting of the W / O type emulsion present in the outer aqueous phase can be kept stable, resulting in good separation between the inner aqueous phase and the outer aqueous phase, and a W / O / W type emulsified cosmetic composition with excellent temporal stability can be obtained. A patent application was filed earlier for this finding (Japanese Patent Application No. 2023-80226). Further studies revealed that when polar oily components such as vitamins, carotenoids, and fragrances, which are often used as ingredients in cosmetics, are included in the oil phase, the dispersion state of the droplets tends to become unstable. Therefore, when incorporating polar oily components, it is useful to avoid including the polar oily components in the oil phase that forms the continuous phase of the W / O type emulsion, and this led to the completion of the present invention.

[0008] Thus, the present invention provides an O / W / O / W type emulsified cosmetic composition in which an O / W / O type emulsion is dispersed in an aqueous phase, comprising an O / W type emulsion in which an inner oil phase containing polar oil is dispersed in an aqueous phase as the dispersed phase, and an oil phase containing dipentaerythrityl tripolyhydroxystearate and not containing the polar oil as the continuous phase, is dispersed in an outer aqueous phase containing a water-soluble polymer.

[0009] The O / W / O / W type emulsified cosmetic composition of the present invention significantly improves upon the shortcomings of conventional W / O / W type emulsified cosmetics, which suffered from poor stability over time. Furthermore, because the inner aqueous phase and outer aqueous phase are well separated, contact between the active ingredients in the inner and outer aqueous phases is prevented, thus preventing instability of the system due to contact between the two components. In addition, polar oily components can be incorporated without impairing the stability of the system.

[0010] The O / W / O / W type emulsified cosmetic composition of the present invention has a structure in which droplets of O / W / O type emulsion are dispersed in a continuous outer aqueous phase. The droplets of O / W / O type emulsion have a structure in which droplets of O / W type emulsion are dispersed in an oil phase, and the aqueous phase in the O / W / O type emulsion is called the inner aqueous phase to distinguish it from the outer aqueous phase that forms the outermost phase of the O / W / O / W type. In the present invention, the O / W / O / W type emulsified cosmetic composition may be a single O / W / O type emulsion dispersed in the outer aqueous phase, or two or more different O / W / O type emulsions dispersed simultaneously in the outer aqueous phase, or it may be a [(O / W / O) + (W / O)] / W type emulsion, [(O / W / O) + (O)] / W type emulsion, etc., in which an O / W / O type emulsion and a W / O type emulsion or oil droplets are dispersed simultaneously in the outer aqueous phase.

[0011] (O / W / O / W type emulsion) In the O / W / O / W type emulsified cosmetic composition of the present invention, the O / W / O type emulsion forms a dispersed phase dispersed in an aqueous phase that forms a continuous phase. The O / W / O type emulsion has an O / W type emulsion in which an inner oil phase containing polar components is dispersed in an aqueous phase as the dispersed phase, and an oil phase containing dipentaerythrityl tripolyhydroxystearate and not containing polar components as the continuous phase. This continuous phase is called the outer oil phase to distinguish it from the inner oil phase containing polar components. The outer oil phase contains dipentaerythrityl tripolyhydroxystearate as an essential component and does not contain polar components. The presence of dipentaerythrityl tripolyhydroxystearate in the outer oil phase allows for the preparation of a stable O / W / O type emulsion. Furthermore, even when this O / W / O type emulsion is dispersed in the outer aqueous phase to form an O / W / O / W type emulsion, the separation of the inner aqueous phase and the outer aqueous phase can be stably maintained.

[0012] (Internal Oil Phase) The internal oil phase, which forms the dispersed phase of the O / W type emulsion, contains a polar oil-soluble component as an essential component, and may optionally contain a non-polar oil component. In this specification, the polar oil-soluble component may be referred to as component (A). The content of such component (A) is 1 to 100% by mass relative to the total amount of the internal oil phase, and the content of the internal oil phase is 0.001 to 50% by mass relative to the total amount of the O / W type emulsion.

[0013] (Polar Components) Specific examples of polar components suitable for inclusion in the inner oil phase include oil-soluble vitamins such as tocopherol, tocopherol acetate, ascorbyl dipalmitate, retinol, retinyl palmitate, and ascorbyl tetrahexyldecanoate; carotenoids such as astaxanthin, lycopene, and β-carotene; essential oils such as orange peel oil, lavender oil, and damask rose flower oil; and UV absorbers such as 2-ethylhexyl paramethoxycinnamate, octyl salicylate, homomenthyl salicylate, bis-ethylhexyloxyphenol methoxyphenyl triazine, dihydroxybenzophenone, octocrylene, 4-tert-butyl-4'-methoxydibenzoylmethane, and diethylamino hydroxybenzoyl hexyl benzoate. Other options include ceramide or similar substances, isopropylmethylphenol, stearyl glycyrrhetinate, bakuchiol, and oil-soluble fragrances.

[0014] These polar components may be used in combination of two or more types, or they may be used as a mixture with polar oils such as ester oils and fats, or with non-polar oils such as polybutene, squalane, and petrolatum.

[0015] (Internal Aqueous Phase) In the present invention, the aqueous phase (internal aqueous phase) that constitutes a part of the dispersed phase of the O / W / O type emulsion, which is the dispersed phase, contains water such as purified water and ion-exchanged water as an essential component, and may optionally contain electrolytes, polyhydric alcohols, water-soluble active ingredients, and other water-soluble or water-dispersible components.

[0016] (Electrolytes) The stability of O / W / O type emulsions is improved when the internal aqueous phase contains an electrolyte. The electrolyte may be an ionic surfactant that functions as a surfactant, not just an electrolyte in the narrow sense. Examples of electrolytes in the narrow sense include inorganic salts such as sodium chloride, potassium chloride, magnesium chloride, sodium sulfate, magnesium sulfate, zinc sulfate, sodium sulfite, sodium thiosulfite, sodium monohydrogen phosphate, sodium dihydrogen phosphate, and trisodium phosphate; salts of organic acids such as lactic acid, acetic acid, benzoic acid, propionic acid, tartaric acid, citric acid, pyrrolidone carboxylic acid, ethylenediaminetetraacetic acid, and glycyrrhizic acid (e.g., ammonium salts, alkali metal salts, alkaline earth metal salts, iron salts, and zinc salts); and ascorbic acid compounds such as ascorbic acid, sodium ascorbyl phosphate, and ascorbyl glucoside.

[0017] Furthermore, examples of ionic surfactants include anionic surfactants, cationic surfactants, and amphoteric surfactants commonly used in the field of cosmetics, as well as compounds that are ionic and have the function of a surfactant. Examples of such compounds include amphiphilic vitamin derivatives such as (ascorbyl / tocopheryl) phosphate K, tocopheryl phosphate sodium, and trisodium ascorbyl palmitate phosphate, salts of lipopeptides such as surfactant sodium, and salts of triterpene glycosides such as potassium glycyrrhizate K2. Examples of anionic surfactants include alkyl phosphates, polyoxyalkylene alkyl ether phosphates, higher fatty acid salts, alkyl sulfonates, alkyl sulfates, and acyl amino acid salts. Examples of cationic surfactants include alkylamines and alkyltrimethylammonium salts. Examples of amphoteric surfactants include lecithins (lecithin, hydrogenated lecithin, lysolecithin, hydroxylated lecithin, etc.), carbobetine-type amphoteric surfactants, sulfobetine-type amphoteric surfactants, and amino acid-type amphoteric surfactants.

[0018] When electrolytes are added, the amount added is preferably 0.1 to 5% by mass relative to the total volume of the internal aqueous phase. In particular, when (ascorbyl / tocopheryl) phosphate K, lecithins, or surfactin Na are included in the aqueous phase, the stability of O / W / O type emulsions is improved, and the stability of O / W / O / W type emulsions is also improved.

[0019] (Outer Oil Phase) In the present invention, the oil phase forming the outer oil phase of the O / W / O type emulsion contains dipentaerythrityl tripolyhydroxystearate as an essential component and does not contain component (A). Here, the phrase "does not contain" does not mean that component (A) is not contained at all, and component (A) may be included in a range that does not essentially impair the effects of the present invention (for example, 1% by mass or less relative to the total amount of the outer oil phase). Furthermore, in the following, dipentaerythrityl tripolyhydroxystearate may be referred to as component (B).

[0020] (Dipentaerythrityl Tripolyhydroxystearate) Dipentaerythrityl tripolyhydroxystearate is a compound in which three of the six hydroxyl groups of dipentaerythritol are ester-bonded to the carboxylic acid group of polyhydroxystearic acid. Dipentaerythrityl tripolyhydroxystearate is typically incorporated into cosmetics as an emollient, water-retaining oil. A commercially available example is Saracos WO-6 manufactured by Nisshin Oillio Co., Ltd.

[0021] In the cosmetic composition of the present invention, the amount of component (B) is preferably 0.1 to 10% by mass, more preferably 0.2 to 8% by mass, and even more preferably 0.3 to 5% by mass, relative to the O / W / O type emulsion, and is preferably 1 to 20% by mass, particularly 5 to 15% by mass, relative to the total amount of the outer oil phase.

[0022] The outer oil phase may contain oils that are liquid at room temperature in addition to component (B). Specific examples of oils include hydrocarbons such as volatile isoparaffins, polybutenes, polyisobutylenes, heavy liquid isoparaffins, liquid paraffins, α-olefin oligomers, squalanes, and petrolatum; and silicone oils such as low-molecular-weight dimethylpolysiloxanes, cyclic silicones, and high-molecular-weight dimethylpolysiloxanes, with hydrocarbons being particularly preferred. The content of such oils that are liquid at room temperature is preferably 80 to 99% by mass of the total amount of the outer oil phase.

[0023] The amount of the aqueous phase (internal aqueous phase) in an O / W / O type emulsion is preferably 5 to 75% by mass, more preferably 10 to 70% by mass, and particularly preferably 10 to 60% by mass, relative to the O / W / O type emulsion. If the amount of the internal aqueous phase is excessively small, the amount of water-soluble active ingredients that can be included in the internal aqueous phase will be limited, and if it is excessively large, the stability of the O / W / O / W type emulsion will decrease, and it will have a sticky feel.

[0024] The inner aqueous phase can contain water-soluble active ingredients. Examples of water-soluble active ingredients include various vitamins, plant extracts, antioxidants, and whitening agents. The O / W / O / W type emulsified cosmetic composition of the present invention allows for reliable separation of the inner aqueous phase and the outer aqueous phase, thus enabling a difference in pH range between the outer aqueous phase and the inner aqueous phase. By utilizing this characteristic, for example, an active ingredient that is poorly soluble in a neutral pH range but water-soluble in a pH range other than neutral can be included in a dissolved state by setting the pH of the inner aqueous phase to a pH other than neutral, thereby preparing a cosmetic composition that is neutral in overall volume.

[0025] The O / W / O / W type emulsified cosmetic composition of the present invention is an O / W / O / W type emulsion in which droplets of the above-mentioned O / W / O type emulsion are dispersed in an outer aqueous phase that forms a continuous phase. The outer aqueous phase mainly consists of water and contains a water-soluble polymer as another essential component. The water can be any type commonly used in the preparation of cosmetics, such as purified water or ion-exchanged water.

[0026] (Water-soluble polymers) By including a water-soluble polymer (hereinafter sometimes referred to as "component (C)") in the outer aqueous phase, coalescence of O / W / O type emulsion droplets in the outer aqueous phase is prevented, and a stable O / W / O / W type emulsified cosmetic can be obtained over time. Specific examples of component (C) include carbomer, alkyl-modified carboxyvinyl polymer, water-soluble polymers containing 2-acrylamido-2-methylpropanesulfonic acid or its salt as constituent units, hydrophobic-modified polyether urethane, and hydrophobic-modified alkylcellulose. The water-soluble polymers exemplified above will be described in more detail below.

[0027] Carbomers, sometimes referred to as carboxyvinyl polymers, are cross-linked copolymers of acrylic acid. Examples of commercially available products include Lubrizol's Carbopol 940, Carbopol 941, Carbopol 980, and Carbopol 981; Sumitomo Seika's AQUPEC HV-501E and AQUPEC HV-505E; and Fujifilm Wako Pure Chemical Industries' Hibiswako-103, Hibiswako-104, and Hibiswako-105.

[0028] Alkyl-modified carboxyvinyl polymers are carboxyvinyl polymers having an alkyl group, and are copolymers or salts thereof of (meth)acrylic acid and alkyl (meth)acrylate. The number of carbon atoms in the alkyl group is preferably 8 to 30. Examples of alkyl-modified carboxyvinyl polymers include (acrylates / alkyl acrylate (C10-30)) crosspolymer, (acrylates / alkyl acrylate (C10-30)) copolymer, (acrylates / ethylhexyl acrylate) copolymer, etc. Examples of commercially available products include Lubrizol's Carbopol 1342 and Carbopol 1382, and Noveon's Pemulene TR-1 and Pemulene TR-2, etc.

[0029] Water-soluble polymers containing 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof as a constituent unit are copolymers or crosspolymers containing 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof as a constituent unit. Note that the term "2-acrylamido-2-methylpropanesulfonic acid" is synonymous with "acryloyldimethyltaurine." Specific examples include (ammonium acryloyldimethyltaurine / VP) copolymer, (sodium acryloyldimethyltaurine / VP) crosspolymer, (dimethylacrylamide / sodium acryloyldimethyltaurine) crosspolymer, (acrylamido / sodium acryloyldimethyltaurine) copolymer, (sodium acrylate / sodium acryloyldimethyltaurine) copolymer, and (hydroxyethyl acrylate / sodium acryloyldimethyltaurine) copolymer. Examples of commercially available products include FLOCARE PSD-30, manufactured by SNF, which is a (sodium acrylate / sodium acryloyldimethyl taurate) copolymer; SIMULGEL-EG, manufactured by SEPPIC, which is a dispersion containing this polymer; SIMULGEL-NS, which is a dispersion containing a (hydroxyethyl acrylate / sodium acryloyldimethyl taurate) copolymer; and SEPINOV EMT10, manufactured by SEPPIC, which is a (hydroxyethyl acrylate / sodium acryloyldimethyl taurate) copolymer.

[0030] Hydrophobic modified polyether urethanes are associative polymers having urethane bonds, such as (PEG-240 / decyltetradeceth-20 / HDI) copolymer and polyurethane-59. Examples of commercially available products include Adekanol GT-700 and Adekanol GT-930 from ADEKA Corporation. Hydrophobic modified alkylcelluloses have a structure in which a long-chain alkyl group is introduced into a water-soluble cellulose ether derivative, such as stearoxyhydroxypropyl methylcellulose. Examples of commercially available products include Sanjelose 90L, 90M, 90H, 60L, 60M, and 60H from Daido Chemical Industries, Ltd.

[0031] Component (C) is preferably contained in the cosmetic composition in an amount of 0.01 to 10% by mass, and more preferably in an amount of 0.1 to 8% by mass. If the content of component (C) is excessively low, the stability of the O / W / O / W type emulsion tends to decrease, while if it is excessively high, the viscosity increases, resulting in a sticky feel.

[0032] In the O / W / O / W type cosmetic composition of the present invention, the content of the O / W / O type emulsion is preferably 0.05 to 60% by mass, more preferably 0.1 to 50% by mass, and particularly preferably 0.5 to 40% by mass, relative to the total cosmetic composition. If the content of the O / W / O type emulsion is excessively low, the internal aqueous phase cannot contain a large amount of active ingredients, etc. If it is excessively high, the stability of the O / W / O / W type emulsion decreases, and the composition becomes sticky.

[0033] The O / W / O / W type emulsified cosmetic composition of the present invention can be manufactured, for example, as follows: Component (A) is added to an oil phase mixture (or the single component if the oil phase is formed from a single component) according to a conventional method. This mixture is then added to water or an aqueous solution forming the internal aqueous phase to prepare an O / W type emulsion. This emulsion is then added to an external oil phase mixture containing component (B) to generate an O / W / O type emulsion. The resulting O / W / O type emulsion is then dispersed in an external aqueous phase mixture in which component (C) has been dissolved to form an O / W / O / W type emulsion. Alternatively, two or more O / W / O type emulsions with different compositions can be prepared and dispersed in an external aqueous phase mixture to create an O / W / O / W type emulsified cosmetic composition containing multiple types of O / W / O type emulsion droplets. Furthermore, by dispersing a W / O type emulsion or oil in the outer aqueous phase along with an O / W / O type emulsion, a composite emulsion with the configuration of [(O / W / O) + (W / O)] / W or [(O / W / O) + (O)] / W can be formed, and these can also be combined.

[0034] The form of the O / W / O / W type emulsified cosmetic composition of the present invention is not particularly limited, and a wide range of ordinary cosmetic forms can be adopted. Specific examples of forms include, for example, lotion (liquid), gel, emulsion, suspension, and cream.

[0035] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, the amounts of ingredients in the formulations described below are expressed as mass percent of the total amount.

[0036] The evaluation methods for W / O / W type emulsions and O / W / O / W type emulsions in the following reference examples, examples, and comparative examples are as follows: (Emulsification state after 3 days) Three days after preparing the cosmetic composition, the emulsion droplets were observed using an optical microscope at 100x magnification and evaluated in four stages according to the following criteria. Criterion A below indicates that minute droplets of less than 30 μm consisting of a W / O type emulsion (in the case of the reference example) or an O / W / O type emulsion (in the case of the examples and comparative examples) are uniformly dispersed, and that the W / O / W type or O / W / O / W type emulsion is in a stable state. On the other hand, criterion D below indicates that the mixture is divided into a portion where droplets consisting of W / O type emulsion or O / W / O type emulsion have coalesced, and a portion where there is no dispersed emulsion, indicating that the W / O / W type emulsion (in the case of the reference example) or O / W / O / W type emulsion (in the case of the examples and comparative examples) is in an unstable state.

[0037] (Evaluation Criteria) A: The dispersed phase consists of uniformly dispersed droplets with a diameter of 1 μm or more and less than 30 μm. B: The dispersed phase contains scattered droplets with a diameter of 30 μm or more and less than 50 μm, but the droplets are uniformly dispersed. C: The dispersed phase contains scattered droplets with a diameter of 50 μm or more. D: The dispersed phase is divided into areas where the droplets are coalesced and areas where there are no droplets.

[0038] Reference Examples 1-4 (W / O / W type whitening cosmetic) W / O / W type whitening cosmetic formulations shown in Table 1 were prepared according to the following manufacturing procedure and evaluated by the method described above. The results are shown in Table 1. Note that Reference Example 1 is the same as Example 1 of Japanese Patent Application No. 2023-80226, and Reference Examples 2-4 are the same as Comparative Examples 1-3 of Japanese Patent Application No. 2023-80226, respectively. (Manufacturing Procedure) (1) After uniformly mixing each component of the internal aqueous phase and oil phase described in Table 1 to prepare the internal aqueous phase mixture and the oil phase mixture, the internal aqueous phase mixture is gradually added to the oil phase mixture while stirring to obtain a W / O type emulsion. (2) After uniformly mixing each component of the external aqueous phase described in Table 1 to prepare the external aqueous phase mixture, the above W / O type emulsion is gradually added to the external aqueous phase mixture while stirring to obtain a W / O / W type emulsion.

[0039]

[0040] In Reference Example 1, the W / O / W type whitening cream showed uniformly dispersed emulsion droplets of approximately 5 μm in size even after microscopic observation following 3 days. Furthermore, at a magnification of 400x, multiple water droplets were observed within the oil droplets. In contrast, in Reference Examples 2-4, the W / O / W type whitening creams, which used commercially available raw materials commonly used as W / O emulsifiers instead of dipentaerythrityl tripolyhydroxystearate, showed coalescence of W / O type emulsion droplets. Incidentally, PEG-30 dipolyhydroxystearate used in Reference Example 2 is a type of polyethylene glycol dipolyhydroxystearate recommended as a preferred emulsifier in Patent Document 1.

[0041] Example 1 (Cosmetic composition with anti-inflammatory effect) An O / W / O / W type cosmetic composition containing lauroyl glutamate di(phytosteryl / octyldodecyl), which has an emollient effect, and stearyl glycyrrhetinate, which has an anti-inflammatory effect, was prepared according to the following manufacturing procedure and evaluated by the method described above. The results are shown in Table 2. (Manufacturing procedure) (1) The components of the inner oil phase and inner aqueous phase listed in Table 2 were uniformly mixed to prepare the mixture for the inner oil phase and the mixture for the inner aqueous phase. Then, the mixture for the inner oil phase was gradually added to the mixture for the inner aqueous phase while stirring to obtain an O / W type emulsion. (2) The components of the outer oil phase listed in Table 2 were uniformly mixed to prepare the mixture for the outer oil phase. Then, the mixture for the outer oil phase was gradually added to this mixture while stirring to obtain an O / W / O type emulsion. (3) After uniformly mixing the components of the outer aqueous phase listed in Table 2 to prepare the outer aqueous phase mixture, the O / W / O type emulsion obtained in (2) above was gradually added to this mixture while stirring to obtain an O / W / O / W type emulsion.

[0042] Comparative Example 1 A 0 / W / 0 / W type cosmetic composition was prepared in the same manner as in Example 1, except that stearyl glycyrrhetinate, which was incorporated into the inner oil phase in Example 1, was incorporated into the outer oil phase. The composition was then evaluated using the method described above. The results are shown in Table 2. Note that since the inner oil phase of Comparative Example 1 consists only of dilauroyl glutamate (phytosteryl / octyldodecyl), no mixing with other components is necessary.

[0043] Example 2 (Cosmetic having whitening effect) An O / W / O / W type cosmetic containing dilauroyl glutamate (phytosteryl / octyldodecyl) having an emollient effect and ascorbyl tetrahydroxyhexadecenoate having a whitening effect was prepared according to the following production procedure and evaluated by the above method. The results are shown in Table 2. (Production procedure) (1) After uniformly mixing the components of the internal aqueous phase described in Table 2 to prepare a mixture for the internal aqueous phase, the components for the internal oil phase were gradually added to the mixture for the internal aqueous phase while stirring to obtain an O / W type emulsion. (2) After uniformly mixing the components of the external oil phase described in Table 2 to prepare a mixture for the external oil phase, the O / W type emulsion obtained in (1) above was gradually added to this mixture while stirring to obtain an O / W / O type emulsion. (3) After uniformly mixing the components of the external aqueous phase described in Table 2 to prepare a mixture for the external aqueous phase, the O / W / O type emulsion obtained in (2) above was gradually added to this mixture while stirring to obtain an O / W / O / W type emulsion.

[0044] Comparative Example 2 An O / W / O / W type cosmetic was prepared in the same manner as in Example 2, except that ascorbyl tetrahydroxyhexadecenoate incorporated in the internal oil phase in Example 2 was incorporated in the external oil phase, and 2.50% of dilauroyl glutamate (phytosteryl / octyldodecyl) was included in the internal oil phase, and evaluated by the above method. The results are shown in Table 2.

[0045] Example 3 (Cosmetic having anti-aging effect) An O / W / O / W type cosmetic containing di(phytostearyl / octyldodecyl) lauroyl glutamate having an emollient effect and bakuchiol having an anti-aging effect was prepared according to the following production procedure and evaluated by the above method. The results are shown in Table 2. (Production procedure) (1) After uniformly mixing each component of the innermost oil phase and the inner aqueous phase described in Table 2 to prepare a mixture for the innermost oil phase and a mixture for the inner aqueous phase, the mixture for the innermost oil phase was gradually added to the mixture for the inner aqueous phase while stirring to obtain an O / W type emulsion. (2) After uniformly mixing the components of the outer oil phase described in Table 2 to prepare a mixture for the outer oil phase, this mixture was gradually added to the O / W type emulsion obtained in (1) above while stirring to obtain an O / W / O type emulsion. (3) After uniformly mixing the components of the outer aqueous phase described in Table 2 to prepare a mixture for the outer aqueous phase, the O / W / O type emulsion obtained in (2) above was gradually added to this mixture while stirring to obtain an O / W / O / W type emulsion.

[0046] Comparative Example 3 A W / O / W type cosmetic was prepared in the same manner as in Example 3, except that bakuchiol blended in the inner oil phase in Example 3 was blended in the outer oil phase, and evaluated by the above method. The results are shown in Table 2. Note that, as in Comparative Example 1, the inner oil phase is composed only of di(phytostearyl / octyldodecyl) lauroyl glutamate, so the operation of mixing with other components is unnecessary.

[0047] Example 4 (Aromatherapy cosmetic) An O / W / O / W type cosmetic containing di(phytostearyl / octyldodecyl) lauroyl glutamate having an emollient effect and orange peel oil having an aromatherapy effect was prepared according to the same production procedure as in Example 1 and evaluated by the above method. The results are shown in Table 2.

[0048] Comparative Example 4 A W / O / W type cosmetic composition was prepared in the same manner as in Example 4, except that the orange peel oil, which was incorporated into the inner oil phase in Example 4, was incorporated into the outer aqueous phase, and the amount of dilauroyl glutamate (phytosteryl / octyldodecyl) incorporated into the inner oil phase was changed from 1.5% to 2.50%, and the composition was evaluated using the method described above. The results are shown in Table 2. Note that since the inner oil phase of Comparative Example 4 consists only of dilauroyl glutamate (phytosteryl / octyldodecyl), there is no need to mix it with other components.

[0049]

[0050] The following are notes regarding the ingredients listed in Table 2: *1 Product name: Saracos WO-6, manufactured by Nisshin Oillio Co., Ltd. *5 Product name: CARBOPOL 1382, manufactured by Polymer Lubrizol Co., Ltd. *6 Product name: ELDEW PS-203R, manufactured by Ajinomoto Co., Inc. *7 Product name: C-O Gretinol, manufactured by Maruzen Pharmaceutical Co., Ltd. *8 Product name: NIKKOL VC-IP, manufactured by Nikko Chemicals Co., Ltd. *9 Product name: BAKUCHIOL 99%, manufactured by L.B.H. Co., Ltd. *10 Product name: ORANGE OIL CP, manufactured by Kobayashi Fragrance Co., Ltd. *11 Product name: EPC (SENJU), manufactured by Senju Pharmaceutical Co., Ltd. *12 Product name: C-O Gretinol, manufactured by Maruzen Pharmaceutical Co., Ltd. *13 Product name: NIKKOL VC-IP, manufactured by Nikko Chemicals Co., Ltd.

[0051] The cosmetic compositions of Examples 1 to 4 exhibited excellent stability as O / W / O / W type emulsions because the polar, oily active ingredient was contained in the inner oil phase. On the other hand, the cosmetic compositions of Comparative Examples 1 to 4, in which the polar, oily active ingredient was contained in the outer oil phase, were unable to prepare a uniformly dispersed O / W / O type emulsion because the O / W / O type emulsion that forms the dispersed phase was unstable.

[0052] Example 5 An O / W / O type cosmetic was prepared in the same manner as in Example 1, except that hydrogenated lecithin (trade name SLP-PC70HS, manufactured by Tsuji Oil Co., Ltd.) was used instead of (ascorbyl / tocopheryl) potassium phosphate, which was used as an ingredient for the inner aqueous phase in the preparation of the O / W / O type emulsion in Example 1. The cosmetic was then evaluated using the method described above. As a result, results almost identical to those of Example 1 were obtained.

[0053] Example 6 An O / W / O type cosmetic was prepared in the same manner as in Example 1, except that (ascorbyl / tocopheryl) potassium phosphate, which was used as an ingredient for the inner aqueous phase in the preparation of the O / W / O type emulsion in Example 1, was replaced with surfactant sodium (trade name KANEKA SURFACTIN, manufactured by Kaneka Corporation), a cyclic peptide composed of amino acids and fatty acids. The cosmetic was then evaluated using the method described above. As a result, results almost identical to those of Example 1 were obtained.

[0054] Example 7 An O / W / O type cosmetic was prepared in the same manner as in Example 1, except that hydrogenated lecithin (trade name SLP-PC70HS, manufactured by Tsuji Oil Co., Ltd.) was used instead of (ascorbyl / tocopheryl) potassium phosphate, which was used as an ingredient for the inner aqueous phase in the preparation of the O / W / O type emulsion in Example 1. The cosmetic was then evaluated using the method described above. As a result, results almost identical to those of Example 1 were obtained.

[0055] Example 8 An O / W / O type cosmetic was prepared in the same manner as in Example 1, except that hydrogenated lecithin (trade name SLP-PC70HS, manufactured by Tsuji Oil Co., Ltd.) was used instead of (ascorbyl / tocophenyl) potassium phosphate, which was used as an ingredient for the inner aqueous phase in the preparation of the O / W / O type emulsion in Example 1. The cosmetic was then evaluated using the method described above. As a result, results almost identical to those of Example 1 were obtained.

[0056] Example 8 An O / W / O / W type cosmetic was prepared in the same manner as in Example 1, except that liquid paraffin (product name: Hycol K-230, manufactured by Kaneda Co., Ltd.) was used instead of squalane, which was used as an outer oil phase component in the preparation of the O / W / O type emulsion in Example 1. The cosmetic was then evaluated using the method described above. As a result, results almost identical to those of Example 1 were obtained.

[0057] Example 9 An O / W / O / W type cosmetic was prepared in the same manner as in Example 1, except that petrolatum (trade name White Petrolatum, manufactured by Sonneborn) was used instead of squalane, which was used as an outer oil phase component in the preparation of the O / W / O type emulsion in Example 1. The cosmetic was then evaluated using the method described above. As a result, results almost identical to those of Example 1 were obtained.

[0058] The present invention provides an O / W / O / W type emulsified cosmetic composition that has good temporal stability and can be formulated with various active substances.

Claims

1. An O / W / O / W type emulsified cosmetic composition comprising an O / W / O type emulsion in which an inner oil phase containing a polar component (A) is dispersed in an aqueous phase as the dispersed phase, and an oil phase containing dipentaerythrityl tripolyhydroxystearate (B) and not containing the polar component (A) as the continuous phase, dispersed in an outer aqueous phase containing a water-soluble polymer.

2. The O / W / O / W type emulsified cosmetic composition according to claim 1, wherein the water-soluble polymer is at least one selected from the group consisting of carbomer, alkyl-modified carboxyvinyl polymer, water-soluble polymer containing 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof as a constituent unit, hydrophobic-modified polyether urethane, and hydrophobic-modified alkylcellulose.

3. The O / W / O / W type emulsified cosmetic composition according to claim 1 or 2, wherein the polar component is an oil-soluble vitamin, a carotenoid, an essential oil, or an oil-soluble ultraviolet absorber.

4. The O / W / O / W type emulsified cosmetic composition according to claim 1 or 2, wherein the aqueous phase of the O / W type emulsion emulsion contains an electrolyte.

5. The O / W / O / W type emulsified cosmetic composition according to claim 2, wherein the electrolyte is at least one selected from the group consisting of amphiphilic vitamin derivatives, lipopeptides, triterpene glycoside salts, anionic surfactants, cationic surfactants, and zwionic surfactants.

6. The O / W / O / W type emulsified cosmetic composition according to claim 4, wherein the electrolyte is (ascorbyl / tocopheryl) potassium phosphate, lecithins, or sodium surfactant.

7. The O / W / O / W type emulsified cosmetic composition according to claim 1 or 2, wherein the outer oil phase of the O / W type / O type emulsion contains hydrocarbons or silicone oil that are liquid at room temperature.

8. The O / W / O / W type emulsified cosmetic composition according to claim 1 or 2, wherein the O / W / O type emulsion contains dipentaerythrityl tripolyhydroxystearate (B) in a proportion of 0.3 to 5% by mass.

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