JPH11349439A - Oil-in-water type emulsion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition which improves stability of an ester of vitamin A and fatty acid to hydrolysis by including an oil-soluble, anti-oxidant and nonionic-based amphiphatic polymer, together with the ester of vitamin A and fatty acid. SOLUTION: This composition is obtained by including (A) an ester of vitamin A and fatty acid (e.g. ester of vitamin A and acetic acid) preferably at 0.001 to 10 wt.%, based on the whole composition, (B) an oil-soluble, anti-oxidant (e.g. butyl hydroxytoluene) preferably at 0.01 to 10.0 wt.%, and (C) a nonionic- based amphiphatic polymer having a molecular weight of 5,000 or more (e.g. methyl cellulose) preferably at 0.01 to 1.0 wt.%. It is preferable that the composition contains oil at 1.0 wt.% or more based on the total composition, and that the totaled ΣI.O.B of the oily phase is 0.043 or more. The composition is preferably used as a preparation for external use for skin, and may take the form of, e.g. cosmetic water or emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an oil-in-water emulsion composition mainly used as an external preparation for skin and the like. More specifically, the invention relates to an oil-in-water emulsified composition in which a fatty acid ester of vitamin A is stabilized, particularly an essence type.

[0002]

2. Description of the Related Art Vitamin A, such as vitamin A and fatty acid esters of vitamin A, has been known as an effective component for the prevention and treatment of cutaneous keratosis, and also for the prevention and recovery of skin aging. It is blended as an active ingredient in various skin external preparations having these purposes.

[0003] However, these vitamins A are originally extremely unstable components. That is, vitamin A is a component that is easily degraded by isomerization, oxidative decomposition, and the like caused by many factors such as light, air, heat, and metal ions. Therefore, skin external preparations containing such vitamin A have a problem in stability over time,
In addition, there were inconveniences such as excessive care for preservation. Among such unstable vitamin A, various means have been proposed for vitamin A, such as using a chelating agent or an antioxidant, for the purpose of stabilizing the vitamin A in an external preparation for skin. ing.

[0004]

The fatty acid ester of vitamin A is superior in oxidative stability to vitamin A, but is susceptible to hydrolysis due to its structure. Therefore, the currently proposed stabilization method represented by the above-described method can only improve the oxidative stability of the fatty acid ester of vitamin A, and can improve the stability against hydrolysis, which is a problem. Can not. Therefore, the problem to be solved in the present invention is to provide means for improving the stability of the fatty acid ester of vitamin A against hydrolysis.

[0005]

Means for Solving the Problems To solve this problem, the present inventors have intensively studied, particularly, means for stabilizing a fatty acid ester of vitamin A in an essence oil-in-water emulsion composition. As a result, in the oil-in-water emulsion composition, the fatty acid ester of vitamin A and the antioxidant coexist in the oil phase, and by blending a nonionic amphiphilic polymer having a molecular weight of 5,000 or more, The present invention has been completed by finding that the object can be solved.

That is, the present invention provides an oil-in-water type containing a fatty acid ester of vitamin A (hereinafter referred to as "Vitamin A fatty acid ester"), an oil-soluble antioxidant and a nonionic amphiphilic polymer having a molecular weight of 5,000 or more. An emulsion composition is provided. This oil-in-water emulsion composition is particularly preferably used as a skin external preparation.

[0007] One of the factors for specifying the properties of the oil-in-water emulsion composition according to the present invention is {I. O. B. The value I. O. B. Value (Inorganic Organic Balanc
The abbreviation of e is an index indicating the degree of polarity of the oil component, and is a value indicating the ratio of inorganic to organic [the “organic value” is 20 for one carbon atom in the molecule of the oil component. A value calculated based on the inorganic value of another substituent (inorganic group) based on the “inorganic value” of 100 for one hydroxyl group based on the “inorganic value”: [Fujita “Organic analysis”
(1930) Kaniya Shoten, same book, "Prediction of Organic Compounds and Conceptual Diagram of Organic Compounds (Chemical Domain 11-10)" (1957)
Pp. 719-725, Fujita and Akatsuka, "Systematic Organic Qualitative Analysis (Pure Product)", p. 487 (1970) Kazama Shoten, Koda, "Organic Conceptual Diagrams-Basics and Applications", p. 227 (1)
984) Sankyo Shuppan, Yaguchi, "Emulsion Formulation Design by Organic Conception Diagram", page 98 (1985) Nippon Emulsion Co., Ltd., RHEwell, JMHarrison, L. Berg: Ind Eng Chem
36,871 (1944)], and specifically,

I. O. B. Value = Inorganic value of the oil / Organic value of the oil. Then, as defined in the present invention, {I.
O. B. The values are based on the I.V. of each oil constituting the oil phase in the emulsion. O. B. This is the sum of the values.

That is, {I. O. B. Value = inorganic value of oil phase / organic value of oil phase In this formula, the inorganic value of the oil phase is A ×
x + Bxy + Cxz + ... [where A, B, C ...
Represents the inorganic value of each oil component constituting the oil phase in the emulsion on the organic conceptual diagram, and x, y, z... Represent the individual oil components A, constituting the oil phase in the emulsion. B, C... Are the proportions present in the respective oil phases (x + y + z +.
1)], and the organic value of the oil phase is A ′ × x + B ′ ×
y + C '× z + ... (where A', B ', C' ...
Represents the organic value of each oil component constituting the oil phase in the emulsion on the organic conceptual diagram). This ΔI. O. B.
If the value is large, it means that the oil phase has high inorganicity and large polarity.

[0010] As will be described later, silicone oil is
Excluded from the above "each oil constituting the oil phase", in other words, when silicone oil is present in the oil phase,
Assuming that this silicone oil is not present in the oil phase, O. B. The value is calculated.

[0011]

Embodiments of the present invention will be described below. As described above, the oil-in-water emulsified composition according to the present invention (hereinafter, referred to as the emulsified composition of the present invention) is an oil-in-water emulsified composition particularly intended to stabilize the blended vitamin A fatty acid ester. It is.

That is, the emulsified composition of the present invention is an oil-in-water emulsified composition on the premise that it contains a vitamin A fatty acid ester. Examples of the vitamin A fatty acid ester to be stabilized in the emulsified composition of the present invention include vitamin A acetate, vitamin A palmitate, vitamin A propionate and the like. It is not particularly limited as long as it is a "modified vitamin A", and is a target of stabilization in the emulsified composition of the present invention.

When a mixture of these vitamin A fatty acid esters, for example, an animal or vegetable oil containing a vitamin A fatty acid ester obtained from a marine animal or a plant, is added to the emulsified composition of the present invention, the mixture is contained in the animal or vegetable oil. Vitamin A fatty acid esters can also be subject to stabilization in the present invention. The amount of the vitamin A fatty acid ester in the emulsified composition of the present invention is not particularly limited, but is generally 0.0001% by weight or more, and preferably 0.001 to 10% by weight, based on the whole composition.

The emulsified composition of the present invention comprises an oil-in-water emulsified composition containing an oil-soluble antioxidant and a nonionic amphiphilic polymer having a molecular weight of 5,000 or more as means for stabilizing the vitamin A fatty acid ester. A composition.

The "oil-soluble antioxidant" to be incorporated in the emulsion composition of the present invention is an "oil-soluble and antioxidant substance" as long as it can be incorporated into a skin external preparation in terms of safety. There is no particular limitation. Oil-soluble antioxidants are
It is blended in the emulsified composition of the present invention mainly to prevent oxidative decomposition of vitamin A fatty acid ester.

Specific examples of the oil-soluble oxidizing agent that can be incorporated in the emulsion composition of the present invention include, for example, butylhydroxytoluene (hereinafter, referred to as BHT), butylhydroxyanisole (hereinafter, referred to as BHA), α, β, Examples include γ, δ-tocopherol, nordihydroguaiaretin, propyl gallate, fatty acid esters of vitamin C, sorbic acid, and the like. The emulsion composition of the present invention may contain one or more oil-soluble antioxidants.

The amount of the oil-soluble antioxidant in the emulsified composition of the present invention is 0.001 to the whole composition in order to sufficiently prevent the oxidative decomposition of the vitamin A fatty acid ester.
% By weight or more, more preferably 0.01% by weight or more. Although the upper limit of the compounding is not particularly limited,
Generally, it is blended in a range of 10.0% by weight or less based on the whole composition.

The "nonionic amphiphilic polymer having a molecular weight of 5,000 or more" blended in the emulsion composition of the present invention is a "nonionic amphiphilic polymer having a molecular weight of 5,000 or more" having both a nonionic hydrophilic group and a hydrophobic group and having a molecular weight of 50.
It is not particularly limited as long as it can be incorporated into a skin external preparation in terms of safety. A nonionic amphiphilic polymer having a molecular weight of 5000 or more is blended in the emulsified composition of the present invention mainly to prevent hydrolysis of the vitamin A fatty acid ester.

The "nonionic amphiphilic polymer having a molecular weight of 5,000 or more" which can be added to the emulsion composition of the present invention includes, for example, partially saponified polyvinyl alcohol; methylcellulose, ethylcellulose, and the like. Cellulosic polymers such as methylhydroxypropylcellulose, hydroxyethylcellulose and hydroxypropylcellulose;
Cellulose derivative modified with an alkyl group of 0; a copolymer of polyvinylpyrrolidone and a vinyl compound having a hydrophobic group; a poly (oxyethyleneoxypropylene) methylpolysiloxane copolymer, dimethylpolysiloxane.
Polyether-modified silicone such as methyl (polyoxyethylene) siloxane copolymer; a graft copolymer of a compound having a hydrophobic group and polyethylene glycol; and alkylated polyoxyethylene. One or more kinds of the emulsified composition of the present invention have a molecular weight of 5 or more.
000 or more nonionic amphiphilic polymers can be blended.

The molecular weight of the nonionic amphiphilic polymer blended in the emulsion composition of the present invention is 5,000 or more, preferably 10,000 or more, more preferably 20,000 or more. Even if a nonionic amphiphilic polymer having a molecular weight of less than 5000 is blended, the hydrolysis of the vitamin A fatty acid ester cannot be sufficiently prevented, which is not preferable.

The amount of the nonionic amphiphilic polymer having a molecular weight of 5,000 or more in the emulsion composition of the present invention may be 0.01 to 10.0% by weight based on the whole composition. Preferably, more preferably 0.01 to 3.
0% by weight, most preferably 0.01 to 1.0% by weight. If the amount of the nonionic amphiphilic polymer having a molecular weight of 5,000 or more is less than 0.01% by weight based on the whole composition, it is difficult to emulsify the system, which is not preferable.
If the amount is more than 10% by weight, the stability of the vitamin A fatty acid ester tends to decrease, and a composition satisfactory in usability cannot be obtained.

The emulsion composition of the present invention has a molecular weight of 5000
In addition to the above nonionic amphiphilic polymers, general surfactants, specifically, nonionic surfactants, cationic surfactants, anionic surfactants or amphoteric surfactants Is highly likely to impair the desired effect of the present invention, and it is generally difficult to formulate while maintaining the desired effect of the present invention. It does not prevent the incorporation of the surfactant.

The oil component selectively blended in the emulsified composition of the present invention is based on the ΔI. O. B. It is preferable to select and blend one or more oils so that the value is 0.043 or more, and it is more preferable to select and blend such oils so that the value is 0.128 or more. Oil phase ΔI.
O. B. If the value is less than 0.043, the stability of the vitamin A fatty acid ester in the system tends to decrease depending on the composition, which is not preferable.

[0024] The ΔI. O. B. As the value increases, the polarity of the entire oil phase increases, and vitamin A in the oil phase increases.
The degree to which the fatty acid ester moves to the aqueous phase and to the interface is reduced, and the stability of the vitamin A fatty acid ester in the oil phase can be improved.

As the oil component of the emulsified composition of the present invention, silicone oil can be blended. However, in this silicone oil, since there is no carbon atom in the molecule in principle, ΔI. O. B. Although excluded from the concept of value (as described above), these silicone oils have an adverse effect on the intended effect of the present invention, the stability of vitamin A fatty acid ester, in the emulsified composition of the present invention. Not given, {I. O. B. It does not change the value.

The amount of the oil component in the emulsion composition of the present invention is preferably at least 1.0% by weight, more preferably at least 3.0% by weight, based on the whole composition. When this amount is less than 1.0% by weight based on the whole composition, vitamin A in the emulsified composition of the present invention is used.
The stability of the fatty acid ester tends to decrease, which is not preferable. If the oil content exceeds 80.0% by weight, it may be difficult to maintain a stable oil-in-water emulsion system, which is not preferable.

In the emulsified composition of the present invention, the oil component to be blended is not particularly limited as long as the above conditions are satisfied. Can be appropriately selected so as to satisfy the condition (1) and blended in the emulsion composition of the present invention.

The emulsion composition of the present invention is an oil-in-water emulsion composition which can be mainly used as an external preparation for the skin of cosmetics, pharmaceuticals, quasi-drugs and the like. Some are referred to as the skin external preparation of the present invention). Hereinafter, an embodiment of the present invention as a skin external preparation will be described.

As a specific form of the external preparation for skin of the present invention, for example, lotions, emulsions, creams, serums, packs and the like can be used. In the skin external preparation of the present invention, the general efficacy of the skin external preparation is not limited as long as the intended effect of the present invention of stabilizing the above-mentioned vitamin A fatty acid ester is not impaired. Components and base components can be blended.

As a medicinal component, for example, when the external preparation for skin of the present invention is used as a sun care product, a benzoic acid-based ultraviolet absorber such as paraaminobenzoic acid; an anthranilic acid-based ultraviolet absorber such as methyl anthranilate; octyl salicylate , Salicylic acid-based UV absorbers such as phenyl salicylate and homomenthyl salicylate; isopropyl paramethoxycinnamate, octyl paramethoxycinnamate, 2-ethylhexyl paramethoxycinnamate, mono-2-ethylhexane diparamethoxycinnamate Glyceryl acid,
[4-bis (trimethylsiloxy) methylsilyl-3-
Methylbutyl] -3,4,5-trimethoxycinnamic acid esters and other cinnamic acid-based ultraviolet absorbers; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone- Benzophenone ultraviolet absorbers such as 5-sulfonic acid and sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate; urocanic acid, ethyl urocanate, 2-phenyl-5-methylbenzoxazole, 2- (2′- Hydroxy-5'-methylphenyl)
Ultraviolet absorbers such as benzotriazole and 4- tert -butyl-4'-methoxydibenzoylmethane can be incorporated into the external preparation for skin of the present invention.

In order to impart a moisturizing effect to the skin external preparation of the present invention, polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, hexylene glycol, glycerin, diglycerin, xylitol, maltitol, Maltose, D
-It may contain humectants such as mannitol, water candy, glucose, fructose, lactose, sodium chondroitin sulfate, sodium hyaluronate, sodium adenosine phosphate, sodium lactate, bile salts, pyrrolidone carboxylic acid, glucosamine, cyclodextrin, etc. it can.

Furthermore, vitamins which can be used for other than the use as antioxidants as drug components; hormones such as estradiol and ethinyl estradiol; arginine;
Aspartic acid, cystine, cysteine, methionine,
Amino acids such as serine, leucine and tryptophan; anti-inflammatory agents such as allantoin, azulene and glycyrrhetinic acid; whitening agents such as arbutin; astringents such as zinc oxide and tannic acid; cooling agents such as L-menthol and camphor; Lysozyme chloride, pyridoxine hydrochloride, γ-oryzanol and the like can be added.

Further, various extracts having various medicinal effects can be blended. That is, dokudami extract,
Oak extract, melilot extract, bonito extract, liquorice extract, peonies extract, bonsai extract, loofah extract, kina extract, saxifrage extract,
Clara extract, cucumber extract, fennel extract, primrose extract, rose extract, syrup extract, lemon extract, sicon extract, aloe extract, shobu root extract, eucalyptus extract, horsetail extract, sage extract, thyme extract, tea extract, seaweed extract, cucumber extract, clove Extracts, raspberry extract, melissa extract, carrot extract, marronie extract, peach extract, peach leaf extract, mulberry extract, cornflower extract, hamamelis extract, placenta extract, thymus extract, silk extract, etc. may be incorporated into the external preparation for skin of the present invention. it can.

It should be noted that these active ingredients are not limited to active ingredients that can be incorporated into the skin external preparation of the present invention.
In addition to the above-mentioned medicinal ingredients being used alone in the external preparation for skin of the present invention, two or more kinds of the above-mentioned medicinal ingredients can be appropriately combined and compounded according to the purpose.

As the base component, a generally known base component, etc., depending on the specific desired form and dosage form, may be used in such an amount that the intended effect of the present invention is not impaired by its combination (especially, oil content). Must be mixed with care).

Linseed oil, camellia oil, macadamia nut oil, corn oil, mink oil, olive oil,
Avocado oil, sasanqua oil, castor oil, safflower oil, ginger oil, cinnamon oil, jojoba oil, grape oil, sunflower oil, almond oil, rapeseed oil, sesame oil, wheat germ oil,
Liquid oils such as rice germ oil, rice bran oil, cottonseed oil, soybean oil, peanut oil, teaseed oil, evening primrose oil, egg yolk oil, cow foot oil, liver oil, triglycerin, glycerin trioctanoate, glycerin triisopalmitate; Liquid or solid fats and oils such as oil, palm oil and palm kernel oil; solid fats and oils such as cacao butterfat, sheep butterfat, lard, horse fat, hardened oil, hardened castor oil, mocro, shea butter; beeswax, candelilla Waxes such as wax, cotton wax, carnauba wax, bayberry wax, ibotaro wax, whale wax, montan wax, bran wax, lanolin, reduced lanolin, hard lanolin, kapok wax, sugarcane wax, jojoba wax, shellac wax and the like may be incorporated into the external preparation for skin of the present invention. it can.

Also, octanoic acid esters such as cetyl octanoate, glycerin tri-2-ethylhexanoate, isooctanoic acid esters such as pentaerythrit tetra-2-ethylhexanoate, lauric acid esters such as hexyl laurate, and myristine Myristic acid esters such as isopropyl octyl myristate and octyl dodecyl myristate; palmitic acid esters such as octyl palmitate; stearic acid esters such as isocetyl stearate; ,
Oleic acid esters such as isodecyl oleate, adipic acid diesters such as diisopropyl adipate, sebacic acid diesters such as diethyl sebacate, and ester oils such as diisostearyl malate; liquid paraffin, ozokerite, squalane, squalene, pristane, paraffin, Hydrocarbon oils such as isoparaffin, ceresin, vaseline, and microcrystalline wax can be blended in the skin external preparation of the present invention.

Chain silicones such as dimethylpolysiloxane, methylphenylpolysiloxane and methylhydrogenpolysiloxane; cyclic silicones such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane;
Silicone such as silicone resin and silicone rubber having a three-dimensional network structure can be blended in the skin external preparation of the present invention.

Further, lower alcohols such as methanol, ethanol, propanol and isopropanol; and sterols such as cholesterol, sitosterol, phytosterol and lanosterol can be incorporated into the external preparation for skin of the present invention.

Plants such as gum arabic, gum tragacanth, galactan, carob gum, guar gum, karaya gum, carrageenan, pectin, agar, quince seed (quince), alge colloid (brown algae extract), starch (rice, corn, potato, wheat) Macromolecules, microbial macromolecules such as dextran, succinoglucan, pullulan, starch macromolecules such as carboxymethyl starch and methylhydroxypropyl starch, animal macromolecules such as collagen, casein, albumin, gelatin, methylcellulose, nitro Cellulose, ethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, cellulose sodium sulfate,
Cellulosic polymers such as hydroxypropylcellulose, sodium carboxymethylcellulose, crystalline cellulose and cellulose powder; alginic acid polymers such as sodium alginate and propylene glycol alginate; and vinyl polymers such as polyvinyl methyl ether and carboxyvinyl polymer (such as CARBOPOL). Molecule, polyoxyethylene polymer, polyoxyethylene polyoxypropylene copolymer polymer, acrylic polymer such as sodium polyacrylate, polyethyl acrylate, polyacrylamide, polyethyleneimine, cationic polymer, bentonite, silica Water-soluble polymers such as inorganic water-soluble polymers such as aluminum magnesium silicate, laponite, hectorite, and silicic acid anhydride may be incorporated into the external preparation for skin of the present invention. Kill.

Furthermore, sequestering agents such as alanine, edetate sodium salt, sodium polyphosphate, sodium metaphosphate, phosphoric acid and the like; 2-amino-2-methyl-
1-propanol, 2-amino-2-methyl-1,3-
Neutralizing agents such as propanediol, potassium hydroxide, sodium hydroxide, L-arginine, L-lysine, triethanolamine, sodium carbonate; lactic acid, citric acid, glycolic acid, succinic acid, tartaric acid, dl-malic acid, carbonic acid An antioxidant such as a pH adjuster such as potassium, sodium bicarbonate, ammonium bicarbonate and the like can be incorporated in the skin external preparation of the present invention.

Also, benzoic acid, salicylic acid, carboxylic acid, paraoxybenzoate, parachloromethcresol, hexachlorophen, benzalkonium chloride, chlorhexidine chloride, trichlorocarbanilide, photosensitizer,
Antibacterial agents such as phenoxyethanol and parabens can be incorporated into the skin external preparation of the present invention.

Further, if necessary, appropriate fragrances, pigments and the like can be added to the external preparation for skin of the present invention as long as the desired effects of the present invention are not impaired. Here, the above-mentioned base components are examples, and the base components that can be blended with the external preparation for skin of the present invention are not limited to these base components. These base components can be combined in the skin external preparation of the present invention in an appropriate combination in accordance with a formulation according to a desired form. The specific formulation of the emulsion composition of the present invention will be described later.

[0044]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the technical scope of the present invention. In addition, the compounding amount in these Examples is% by weight based on the whole system in which the component is compounded, unless otherwise specified.

Evaluation method of stability of vitamin A fatty acid ester
Method In this example, in order to evaluate the stability of the formulated vitamin A fatty acid ester, the residual ratio of the vitamin A fatty acid ester in the preparation was used as an evaluation index, and the light was shielded with aluminum foil for one month at 50 ° C. The residual ratio of the vitamin A fatty acid ester after storage relative to before storage in the preparation after storage was determined by analyzing with high performance liquid chromatography, and this was defined as the residual ratio (%) as the evaluation index ( Hereinafter, the residual rate obtained in this manner is
It is simply called the survival rate.)

The high performance liquid chromatography for determining the residual ratio was performed under the following conditions. Column: C18 column (manufactured by Shiseido Co., Ltd.) Detection: UV 310 nm Mobile phase: 72% methanol / 10% acetonitrile / 1
8% ion exchange water / 0.5% acetic acid (when detecting retinol acetate) 100% methanol / 0.5% acetic acid (when detecting retinol palmitate)

The residual ratio is preferably as close to 100% as possible. In the present invention, whether or not the residual ratio is 80% or more is determined by determining whether or not the stabilizing action of the vitamin A fatty acid ester is recognized. Line. That is, those having a residual rate of 80% or more were evaluated as acceptable, and those having a residual rate of less than 80% were evaluated as unacceptable.

<< I. O. B. Calculation method of value Based on the calculation method described above, the ΔI.
O. B. Values were calculated.

In the examples and comparative examples of the formulations shown in Tables 1 to 3 below, the above-mentioned investigation was carried out, and the effect in the present invention was examined. The results are also shown in these tables. In addition, each preparation in each table was converted to an aqueous phase at room temperature.
The oil phase heated to 70 ° C. was added, and the mixture was emulsified uniformly with a homomixer and cooled to room temperature to prepare.

[0050]

[Table 1]

In Table 1, Examples 1 to 3
PVA EG-05 (manufactured by Nippon Synthetic Chemical Industry, molecular weight: 30,000), NATROSOL Plus330 (manufactured by Hercules, molecular weight: 5000), which is a nonionic amphiphilic polymer having a molecular weight of 5000 or more within the allowable range.
1.5 million) or poly (oxyethyleneoxypropylene)
This is an example in which a methylpolysiloxane copolymer (molecular weight: 50000) is blended. In contrast, Comparative Example 1 had a molecular weight of 50
In place of the nonionic amphiphilic polymer of at least 00, polyoxyethylene (PO in the table) which is a nonionic surfactant is used.
(Abbreviated as E) (20) An example in which stearyl ether was blended and Comparative Example 2 did not contain BHT, which is an oil-soluble antioxidant, and polyoxyethylene (POE in the table) which was a nonionic surfactant. (Abbreviated as (60)) is an example in which hydrogenated castor oil is blended. From these results, it can be seen that the molecular weight is 500
Example 1 containing 0 or more nonionic amphiphilic polymers
In Comparative Examples 1 to 3, vitamin A was compared with Comparative Examples 1 and 2.
It has been revealed that retinol acetate, which is a fatty acid ester, has remarkably high stability over time.

[0052]

[Table 2]

In Table 2, Examples 4 to 10 are shown.
Changes the compounding pattern of the oil constituting the oil phase,
I. O. B. Change the value, {I. O. B. It is an examination of the correlation between the value and the stability over time of the vitamin A fatty acid ester.

From these results, ΔI. O. B. It was found that the higher the value, that is, the higher the inorganicity of the oil phase and the higher the polarity, the more the stability of the vitamin A fatty acid ester with time was improved.

[0055]

[Table 3]

In Table 3, Example 11 and Comparative Example 3
Is an example in which retinol palmitate is blended as a vitamin A fatty acid ester. From these results, it has been clarified that, in the emulsified composition of the present invention, the temporal stability of the vitamin A fatty acid ester is improved regardless of the type of the vitamin A fatty acid ester to be added.

[0057]

According to the present invention, there is provided an emulsified composition in which a vitamin A fatty acid ester is stabilized in a preparation, particularly useful as an external preparation for skin.

Claims (4)

[Claims] 1. An oil-in-water emulsion composition comprising a fatty acid ester of vitamin A, an oil-soluble antioxidant and a nonionic amphiphilic polymer having a molecular weight of 5,000 or more. 2. The oil-in-water emulsion composition according to claim 1, wherein the amount of the oil component in the oil-in-water emulsion composition is 1.0% by weight or more based on the whole composition. 3. The method of claim 1, wherein the oil phase has a ΔI. O. B. Value is 0.04
The oil-in-water emulsion composition according to claim 1 or 2, wherein the composition is 3 or more. 4. The oil-in-water emulsion composition according to claim 1, wherein the oil-in-water emulsion composition is an external preparation for skin.