JPH07101844A - Multilayered emulsion - Google Patents

Abstract

PURPOSE:To provide an O/W/O type multilayered emulsion prevented in the oxidation of an UV absorber by light or air and reduced in skin irrigation. CONSTITUTION:A multilayered emulsion comprises an O/W/O type multi-layered emulsion to whose inner oil phase an UV absorber has been added. The O/W/O type multilayered emulsion, e.g. the cream type emulsion is prepared by mixing the inner phase containing the UV absorber with a surfactant, preferably a nonionic or anionic surfactant at 70-80 deg.C for preparing an oily phase, heating an aqueous phase suitably containing a water-soluble polymer, a polyhydric alcohol, a water-soluble medicine, etc., at 70-80 deg.C, gradually adding the prepared oily phase to the prepared aqueous phase with stirring, cooling the prepared emulsion to room temperature for affording an O/W/cream, heating an oily phase containing a nonionic surfactant and a raw materials suitable for the outer oil layer, such as a hydrocarbon oil or silicone oil, low in polarity at 55-60 deg.C, gradually adding the prepared O/W cream to the prepared oily phase at 55-60 deg.C, again emulsifying the mixture, and subsequently cooling the emulsion to room temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel multi-layer emulsion containing an ultraviolet absorber, more specifically, O / W.
The present invention relates to a novel multi-layer emulsion in which a UV absorber is mixed in the inner oil phase of an O / O type multi-layer emulsion to suppress oxidation of the UV absorber due to light or air, thereby reducing skin irritation.

[0002]

2. Description of the Related Art It is well known that a sunscreen agent such as an ultraviolet absorber is effective for preventing stains and freckles caused by sunburn, but it is usually effective to apply to the skin with an O / W cream or emulsion. After that, it has a drawback that the desired sunblock effect is reduced as a result of running off from the skin with sweat. From the viewpoint of preventing runoff by sweat as described above, recently, a method of generally incorporating a sunscreen agent such as an ultraviolet absorber into a W / O preparation has been adopted. Further, since the effect of the sunscreen agent generally depends on the blending concentration thereof, the so-called sunscreen preparation for preventing sunburn tends to contain a high concentration of the ultraviolet absorber.

One of the drawbacks of the ultraviolet absorber is that it is irritating, although there are some differences depending on the type and blending amount of the substance. Further, most of the ultraviolet absorbers have a functional group such as a hydroxy group, a carbonyl group, a carboxyl group, a sulfonic acid group and their ethers or esters in the molecule, and many of them are highly polar and fat-soluble substances. However, it is considered that the irritation tends to be slightly promoted because the absorption into the skin is slightly promoted.

On the other hand, in the W / O formulation, since the oil phase containing the ultraviolet absorber is in direct contact with air, the substance mixed in the oil phase which is the continuous phase is oxidized by light and air, causing irritation. It is said that it often produces peroxides and the like. Therefore, antioxidants are usually added to suppress oxidation. However, since antioxidants exert their effects by themselves being oxidized and functioning as reducing agents, in the case of W / O preparations However, the effect of the antioxidant is halved. Therefore, this will spread to various types of stabilizers and large amounts,
As a result, it often resulted in a complicated prescription system that is uncomfortable to use.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, that is, the conventional drawbacks of W / O preparations containing a large amount of an ultraviolet absorber, and in particular, the light of the ultraviolet absorber or It is an object of the present invention to provide a novel multi-layer emulsion which suppresses oxidation by air and reduces skin irritation and has a good feeling in use.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventor has found that in an O / W / O type multi-layer emulsion, a UV absorber is mixed in the inner oil phase. Therefore, they have found that the above problems can be solved, and completed the present invention. That is, according to the present invention, O / W /
In an O-type multi-layer emulsion (hereinafter sometimes simply referred to as "multi-layer emulsion"), a UV absorber is blended in the inner oil phase, which suppresses oxidation of the UV absorber by light or air, and irritates the skin. There is provided a novel multi-layer emulsion having reduced water content.

A general method for producing the multilayer emulsion of the present invention will be described below by taking a cream as an example. <First Step> For example, first, an inner oil phase containing an ultraviolet absorber and / or an antioxidant and a surfactant, preferably a nonionic or anionic surfactant, are heated to 70 to 80 ° C. and mixed. Separately, for example, an aqueous phase appropriately containing a water-soluble polymer, a polyhydric alcohol, a water-soluble drug and the like is heated to 70 to 80 ° C., and the oil phase prepared above is gradually added to this to emulsify, and then to room temperature. Cool to obtain an O / W cream. In order to improve the stability of O / W / O, it is preferable to reduce the surfactant concentration in the aqueous phase during emulsification. Therefore, for example, by forming a gel with an amino acid and a nonionic surfactant, After that, a so-called OD emulsion or an anionic surfactant obtained by a method of uniformly dispersing in an oil phase and then dispersing and emulsifying in an aqueous phase can be used.

<Second Step> Next, the O / W cream is heated again to 55 to 60 ° C. Further, separately, an oil phase containing a nonionic surfactant and a raw material suitable as an external oil phase such as hydrocarbon or silicone oil having low polarity is previously prepared.
To 60 ° C., gradually add the previously prepared O / W cream heated to 55 to 60 ° C., emulsify again, and then cool to room temperature to obtain the desired O / W.
/ O type cream can be obtained. Also, dosage forms other than cream can be manufactured according to the above steps.

In the multi-layer emulsion of the present invention, the internal oil phase is usually 0.5 to 30% by weight of the whole multi-layer emulsion,
The water phase is also 20 to 80% by weight, and the outer oil phase is 1
Although it is 0 to 60% by weight, considering the stability and the feeling of use, the internal oil phase is 5 to 25% by weight of the whole multilayer emulsion, the aqueous phase is 25 to 75% by weight, and the external oil phase is It is also preferably 20 to 50% by weight.

As the ultraviolet absorber blended in the internal oil phase in the present invention, those generally used can be used without particular limitation. Examples thereof include benzophenone-based oxybenzone and oxybenzone sulfonic acid. Dihydroxydimethoxybenzophenone, etc., salicylic acid type ethylene glycol salicylate, homomenthyl salicylate, phenyl salicylate, etc., urocanic acid and ethyl urocanate, cinnamic acid type paramethoxycinnamic acid 2
-Ethylhexyl, octyl methoxycinnamate, etc., paraaminobenzoic acid-based glyceryl paraaminobenzoate, 2-ethylhexyl para-dimethylaminobenzoate, and other dibenzoylmethane-based 4-tert-butyl-4'-
Preferred examples include methoxydibenzoylmethane and the like, and benzotriazole-based 2- (2-hydroxy-5-methylphenyl) benzotriazole, and the like, which may be used alone or in combination of two or more kinds. In addition to these well-known general-purpose components, animal and plant extracts having an ultraviolet absorbing ability may be appropriately combined and used.

As the antioxidant, for example, α-, β-,
Tocopherols such as γ- and δ-tocopherol, Tr
olox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), PMC (2,2,5,7,8-pentamethyl-6-hydroxychroman), gallic acid, propyl gallate , Octyl gallate, shikimic acid, BHA, BHT,
Flavonoids such as catechin, orthotolyl biguanide, dilauryl thiodipropionate, sesamol, resorcin, catechol, saponins, carotenoids with radical scavenging action such as β-carotene, and lipid-soluble eucalyptus extract (oil-soluble) Preferred examples include those mentioned above, which may be used alone or in combination of two or more, and further, NaHSO ₃ , sodium pyrosulfite, ascorbic acid, isoascorbic acid, hydroquinone, Na ₂ S ₂ O ₄ , Uric acid, thiourea, N-acetyl-L-cysteine, glutathione, 2-aminoethylisothiuronium hydrobromide, thyme extract, rosemary extract, eucalyptus extract (1,3-BG extract), etc. If you use water-soluble ones of these, the effect will be further enhanced. Rukoto is preferable.

The amount of the ultraviolet absorber or antioxidant used in the inner oil phase in the present invention is usually 0.1 to 50% by weight, preferably 0.5 to 25% by weight of the whole inner oil phase. % By weight, antioxidants likewise usually 0.0001 to 50% by weight, preferably 0.001 to 25% by weight
Is.

The water-soluble polymer is not particularly limited, and examples thereof include cellulose derivatives such as carboxyvinyl polymer, carboxymethyl cellulose, hydroxyethyl cellulose, cationized cellulose, xanthan gum, sodium alginate, sodium dextran sulfate, pectin and sodium hyaluronate. Mucopolysaccharides such as, polysaccharides produced by mustache, sodium polyacrylate,
Polyvinyl alcohol, polyvinylpyrrolidone, chitosan or its derivative, kefiran or its derivative, curdlan, locust bean gum, guar gum, acrylic acid / alkyl methacrylate copolymer, etc. are appropriately selected alone or in combination of two or more in accordance with the feeling of use. It can be used in combination.

By thus preparing the O / W / O preparation, the ultraviolet absorber can be blended only in the inner oil phase,
It does not impair the original function as an ultraviolet absorber, and improves the drawback of W / O formulation, which is the expression of irritation, which has been conventionally caused by oxidation by light or air or by mixing at a high concentration. Becomes further,
The effect of the antioxidant when the antioxidant is mixed at the same time is effectively exhibited, and the stability of other active ingredients is improved.

Further, for water-soluble drugs which are easily oxidized by light or air, for example, kojic acid, vitamin C, ketotifens such as ketotifen fumarate, etc., UV absorbers and antioxidants are required for formulation. Stabilization is achieved by compounding, but this alone is not enough, and considering the management state at the time of distribution after production and the period from use to consumers and patients, it is relatively difficult to ensure quality. Known as.

For such drugs, the O / W of the present invention
/ O type multi-layer emulsion is extremely effective.
The conventional O / W or W method is to mix a water-soluble drug that is susceptible to oxidation by light or air into the water phase of a / W / O formulation.
It is possible to obtain a higher stabilizing effect than mixing them in the / O formulation.

Most of antioxidants and ultraviolet absorbers are fat-soluble with respect to water-soluble drugs, and it is considered that the degree of the effect of inhibiting oxidation is proportional to the size of the interfacial area between the oil phase and the water phase. Therefore, compared with O / W and W / O preparations,
It is considered that the W / O formulation more efficiently suppresses the oxidation of the water-soluble drug by light or air.

The multi-layer emulsion of the present invention can be used not only as a cosmetic but also as a melasma-induced melasma and sporadic ovale from the viewpoint of beauty to prevent spots and freckles caused by sunburn. It is widely used in the field of medicine from the viewpoint of preventing further deterioration due to ultraviolet rays and the fact that drugs that are easily decomposed by ultraviolet rays can be kept stable in the formulation for patients with pigmentation disorders such as sex pigments. It can be used.

The multilayer emulsion of the present invention is not particularly limited as long as it is suitable for external application, and for example, among medicines, quasi drugs and cosmetics, for example, poultices, plasters, pastes, creams, ointments and aerosols. , Emulsions, emulsions, essences, packs, foundations, sun cares, and other emulsion preparations, which are widely used. Alternatively, the emulsion may be applied to microcapsules suitable for dermal application.

In preparing the multi-layer emulsion of the present invention, various known active ingredients that are commonly used, such as carpronium chloride, cepharanthin, vitamin E, vitamin E nicotinate, nicotinic acid, nicotinic acid amide,
Peripheral vasodilators such as benzyl nicotinate, ginger tincture, capsicum tincture, camphor, menthol,
Cooling agents such as peppermint oil, antibacterial agents such as hinokitiol, benzalkonium chloride, undecylenic acid, adrenocortical hormones, ε-aminocaproic acid, inflammatory agents such as lysozyme chloride, glycyrrhizin and allantoin, whitening agents such as arbutin, placenta extract , Various extracts derived from animals, plants and microorganisms such as liver extract, purple root extract, lactic acid bacterium culture extract, etc. can be appropriately added and used according to the purpose and physical properties at that time. As described above, it is particularly suitable for blending unstable water-soluble drugs.

In addition to the known active ingredients for the above-mentioned pharmaceuticals, quasi-drugs, and cosmetics, in addition to base ingredients such as oils and fats, known humectants, preservatives, UV-scattering agents, and Various additives such as chelating agents, pH adjusters, fragrances and coloring agents can be used in combination.

[0022]

EXAMPLES Next, the present invention will be explained based on examples, but these do not limit the present invention in any way.

The effects of the present invention were confirmed by the following <Experiment 1> to <Experiment 3>. In each experiment, the following common prescription (numerical values represent% by weight) was used as a test sample.

<Cream> Formulation Example 1 Formulation Example 2 Formulation Example 3 (O / W / O) (W / O) (W / O) A Oxybenzone 3.0 3.0 -octyl paradimethylaminobenzoate 2.8 2.8 -Cholesterol 1.0 1.0 1.0 Cetanol 2.0 2.0 2.0 Beef tallow 0.7 0.7 0.7 Cetyl octanoate 3.4 3.4 3.4 Natural vitamin E 0.05 0.05 0.05 B Polyoxyethylene monostearate 1.50 1.50 1.50 Sorbitan (20E.0) C Purified water 58.37 58.37 58.37 Glycerin 5.0 5.0 5.0 Xanthan gum 0.3 0.3 0.3 D Dimethylsiloxane Methyl (Poly 3.0 3.0 3.0 Oxyalkylene) Siloxane Copolymer Methylphenyl Polysiloxane 10.0 10.0 10.0 Methyl Polycyclosiloxane 15.0 15.0 15.0 Natural Vitamin E 0.08 0.08 0.08

<Experiment 1> Light irradiation test experiment method About 2 g of the O / W / O preparation and the W / O preparation prepared above were wrapped in a polyvinylidene chloride film and sealed, and a fade meter (light resistance tester, Suga (About 45 ° C.) for 96 hours. After irradiating with light, it was opened, about 0.5 g of each preparation was accurately weighed, 5 ml of THF was added to sufficiently destroy the emulsion, and then ethanol was added to make 50 ml, and this was used as a sample and remained as an ultraviolet absorber remaining on the HPLC. The amount was quantified, and the residual amount after ultraviolet irradiation with respect to the blended amount was defined as the residual rate. The measurement results are shown in Table 1.

[0026]

Results As can be seen from the results in Table 1, the fade meter 96
Oxybenzone and octyl dimethylaminobenzoate were photolyzed in the W / O formulation by the time irradiation, and the residual rate was reduced. In addition, the appearance changed, and it was slightly yellowish. It is considered that the radicals generated from carbonyl undergo a radical chain reaction with oxygen and other organic compounds to generate oxidation products and other various products. On the other hand, O /
With the W / O formulation, almost no reduction in the residual rate was observed within the error range. From these results, it is considered that by encapsulating the ultraviolet absorber and the antioxidant in the inner oil phase, the radical reaction due to light irradiation and the subsequent oxidation reaction were efficiently suppressed.

<Experiment 2> Usage test Experimental method About 5 g of the O / W / O preparation and the W / O preparation prepared above were irradiated with light by a light resistance tester in the same manner as in the light irradiation test, and three kinds of before irradiation with light were used. We asked 50 healthy volunteers to use the formulation and the formulation after light irradiation in a half-face, and classified the types of irritation into 3 types: muzzle, tingling, and pain sensation. It was examined by a self-reported questionnaire by volunteers. At the same time, the W / O formulation and the O
The difference in the feeling of use of the / W / O preparations and the difference in the feeling of use of these preparations before and after light irradiation were examined by a questionnaire.

Criteria for Comprehensive Evaluation ◎ Those who replied that 50% or more were preferable ○ Those who replied that 10 to less than 50% were favorable △ Those who replied less than 10% or those who answered that 50% or more were normal × 50% or more As a result of the questionnaire, 2% of the O / W / O preparations felt a tingling sensation, whereas 6% of the W / O preparations of Prescription Example 2
Tingling sensation in 2%, tingling sensation in 2%, and in the formulation after irradiation with light, 8% tingling sensation, 6% tingling sensation,
The pain and irritation increased slightly to 2%. In the W / O preparation of Formulation Example 3 in which the ultraviolet absorber was not mixed, only 2% of the eyes had a tingling sensation, and 4% after the irradiation with light, the tingling was only found.

From the above, it was suggested that the W / O formulation would cause the stimulation by the high concentration of the ultraviolet absorber and the increase of the stimulation by the light irradiation. Moreover, these irritation was reduced by the O / W / O formulation in which the ultraviolet absorber was blended in the inner oil phase. Also in terms of usability, the O / W / O formulation was slightly less sticky than the W / O formulation, and the result was that the moist feeling was improved. Furthermore, the difference in the feeling of use before and after the light irradiation was not recognized within the error range. The results of the questionnaire are shown in Table 2 below.

[0031]

<Experiment 3> Patch test results Experimental method 16 healthy males aged 20 to 59 years old, 7 females
A total of 23 subjects were used as test samples of 6 types of creams before and after irradiation of the prescription examples 1, 2 and 3, and the fin chamber (manufactured by EPITEST Ltd. Oy) was used to apply the cream to the lateral arm of the subject. It was judged by performing a patch for 24 hours. That is, the sample is removed 24 hours after the application,
After minutes (shown in Table 5 as 24 hours judgment time), removal 24
After time (shown as a judgment time of 48 hours in Table 5) The judgment complies with the following criteria (Table 3).

[0033] Results Table 4 shows the results of the patch test conducted on 23 test subjects.
-1 and Table 4-2 show the tabulated results.

[0034]

[0035]

In the formulation of Formulation Example 1 (O / W / O formulation of the present invention) before irradiation with light, 30 minutes after removal of the test material (after 24 hours)
(±) was observed in 1 case, but the limbs disappeared 48 hours later. Regarding the formulation after light irradiation of Formulation Example 1, a reaction of (±) was observed in one case as in the pre-irradiation formulation, but 48
I lost my legs after a while.

In Prescription Example 2, the reaction before the light irradiation was observed in (+) 1 case and (±) 4 cases after 24 hours.
After one hour, only one reaction (±) was observed. With the formulation after light irradiation, one case was observed after 24 hours (++),
Responses of (+) 3 cases and (±) 2 cases were observed, and after 48 hours, it was reduced to (+) 1 case and (±) 3 cases, but it was suggested that the stimulation was increased by ultraviolet irradiation.

Prescription example 3 (W / O containing no UV absorber)
In the formulation), one reaction of (±) was observed in the formulation before light irradiation, but the leg disappeared 48 hours later. In the formulation after light irradiation, the reaction of (±) was 1 after 24 hours as in the case before light irradiation.
Some cases were observed, but she lost her leg 48 hours later. Further, the judgment was made 7 days after the sample was removed, but no abnormality was found in all the cases. From the above results, Prescription Examples 1 and 3
In regard to the above, only one case (±) was observed and all 23 cases were negative.

On the other hand, with regard to Formulation Example 2 (W / O preparation containing an ultraviolet absorber), one preparation was positive (+) after 24 hours in the preparation before light irradiation, and four preparations were positive in the preparation after light irradiation. One case was positive after the time, and it decreased with time, but irritation was clearly observed. The cause of the irritation is, as is clear from the comparison with Formulation Example 3, oxybenzone, an ultraviolet absorber,
It is considered to be due to octyl paradimethylaminobenzoate and a photodegradation product (photooxide) of these substances.

Next, a formulation example of the present invention will be shown. In addition, in the compounding ratio, the “appropriate amount” means an amount of 100% by weight in the entire formulation.

[0041]

[Formulation example] <Formulation example 1> Cream (% by weight) A 1.4-tert-butyl-4′-methoxydibenzoylmethane 1.5 2. Cetanol 2.0 3. Beef tallow 3.0 4. Cetyl octanoate 4.4 5. Natural Vitamin E 0.05 B 6. Polyoxy monostearate ethylene sorbitan (20E.0.) 1.50 C 7. Purified water proper amount 8. Glycerin 5.0 9. Xanthan gum 0.3 D 10 .Dimethylsiloxane / methyl (polyoxyalkylene) siloxane copolymer 3.0 11. Methylphenylpolysiloxane 10.0 12. Methylpolycyclosiloxane 15.0 13. Natural vitamin E 0.08

<Formulation Example 2> Cream (% by weight) A 1.4-tert-butyl-4′-methoxydibenzoylmethane 1.5 2. Octyl paramethoxycinnamate 4.7 3. Cetanol 2.0 4. Beef tallow 3.0 5. Cetyl Octanoate 4.4 6. Natural Vitamin E 0.05 B 7. Polyoxy Monostearate Ethylenesorbitan (20E.0.) 1.50 C 8. Purified Water Appropriate amount 9. Glycerin 5.0 10. Xanthan gum 0.3 11. Kojic acid 0.7 12. NaHSO ₃ 0.08 D 13. Dimethyl siloxane / methyl (polyoxyalkylene) siloxane copolymer 3.0 14. Methylphenyl polysiloxane 10.0 15. Methyl polycyclosiloxane 15.0 16. Natural vitamin E 0.08

<Formulation Example 3> Emulsion (% by weight) A 1. Ethylene glycol salicylate 1.5 2. Octyl paramethoxycinnamate 2.5 3. Salix beeswax 1.5 4. Cholesterol 0.6 5. Liquid paraffin 3. 0 6. Propyl gallate 0.005 B 7. Cetyldiethanolamine phosphate 1.20 C 8. Purified water proper amount 9. Glycerin 5.0 10. Carboxyvinyl polymer 0.18 11. Kojic acid 1.5 D 12. Glycerin monostearate 2.0 13. Liquid paraffin 7.0 14. Methyl polycyclosiloxane 6.8

<Formulation Example 4> Emulsion (% by weight) A 1. Ethyl urocanate 0.5 2. Phenyl salicylate 1.5 3. Paradimethylaminobenzoate 2.5 2-Ethylhexyl 4. Microcrystalline wax 1.8 5. Cholesterol 0.6 6. Liquid paraffin 3.0 7. Catechin 0.005 B 8. Sodium N-acyl-L-glutamate 0.80 C 9. Purified water proper amount 10. Glycerin 5.0 11. Carboxyvinyl Polymer 0.18 12.1,3-BG 2.0 13. Thyme extract 0.01 D 14. Dimethylsiloxane-methyl (polyoxyalkylene) siloxane copolymer 2.0 15. Methylphenylpolysiloxane 7.0 16. Methyl polycyclosiloxane 10.0

<Formulation Example 5> Pack (wiping type ) (% by weight) A 1. Ethylene glycol salicylate 2.5 2. Ethyl urocanate 1.7 3. Cholesterol 2.5 4. Cholesteryl stearate 1.5 5 Glyceryl trioctanoate 4.4 6. Natural vitamin E 0.05 B 7. Polyoxy monostearate 1.5 Ethylenesorbitan (20E.O.) C 8. Purified water proper amount 9.NaHSO ₃ 0.03 10. Propylene Glycol 5.0 11. Carboxyvinyl polymer 0.3 12. Polyvinyl alcohol 0.1 D 13. Dimethyl siloxane / methyl (polyoxyalkylene) siloxane copolymer 3.0 14. Liquid paraffin 10.0 15. Refined avocado oil 15.0 16. Natural Vitamin E 0.04

<Formulation Example 6> Pack (wiping type ) (% by weight) A 1. Oxybenzone 2.3 2. Cholesterol 2.5 3. Cholesteryl stearate 1.5 4. Glyceryl trioctanoate 4.4 5. BHA 0.05 B 6. Polyoxy ethylene sorbitan monostearate (20 E.O.) 1.5 C 7. Purified water Appropriate amount 8. NaHSO ₃ 0.03 9. Propylene glycol 5.0 10. Carboxyvinyl polymer 0.3 11. Polyvinyl alcohol 0.1 D 12. Glycerin monostearate 3.6 13. Liquid paraffin 13.0 15. Cetyl octoate 12.5 16. Natural vitamin E 0.04

[0047] <Formulation Example 7> Sunscreen emulsion (wt%) A 1. salicylate ethylene glycol 2.5 2.4-tert-butyl-4'-methoxydibenzoylmethane 1.5 3. Parametoki shea Octyl 1 7 4. Cholesterol 2.5 5. Cholesteryl stearate 1.5 6. Glyceryl trioctanoate 4.4 7. Natural vitamin E 0.05 B 8. Polyoxy monostearate ethylene sorbitan (20E.0.) 1.5 9. Sodium N-acyl-L-glutamate 0.1 C 10. Purified water proper amount 11. NaHSO ₃ 0.03 12. Propylene glycol 5.0 13. Carboxyvinyl polymer 0.3 14. Polyvinyl alcohol 0.1 15 .Sucrose fatty acid ester 0.1 D 16. Dimethyl siloxane / methyl (polyoxyalkylene) siloxane copolymer 3.0 17. Fine titanium oxide 3.5 18. Zinc stearate 0.5 19. Decamethylcyclopentasiloxane 7.5 20. Trimethylsiloxysilicic acid 0.5 21. Methylpolysiloxane 10.0 22. Refined avocado oil 1.0 23. Natural vitamins E 0.01

<Formulation Example 8> Sunscreen emulsion (% by weight) A 1. Oxybenzone 3.5 2.4-tert-butyl-4'-methoxydibenzoylmethane 1.5 3. Octyl paramethoxy cinnamate 3.0 4 .Cholesterol 2.5 5. Cholesteryl stearate 1.5 6. Glyceryl trioctanoate 4.4 7. Natural vitamin E 0.05 B 8. Polyoxy monostearate ethylene sorbitan (20E.0.) 1.5 9.N -Acyl-L-sodium glutamate 0.1 C 10. Purified water proper amount 11. NaHSO ₃ 0.03 12. Propylene glycol 5.0 13. Carboxyvinyl polymer 0.3 14. Polyvinyl alcohol 0.1 15. Sucrose Fatty acid ester 0.1 D 16. Dimethyl siloxane / methyl (polyoxyalkylene) siloxane copolymer 3.0 17. Sorbitan monooleate 0.2 18. Fine-grained titanium oxide 3.5 19. Zinc stearate 0.5 20. Decamethylcyclopentasiloxane 7.5 21. Trimethylsiloxysilicic acid 0.5 22. Methylpolysiloxane 10.0 23. Refined jojoba oil 1. 24. Natural Vitamin E 0.01 It was confirmed that each of Formulation Examples 1 to 8 having 0.01 or more is a preparation having a satisfactory effect for the purpose of the present invention.

[0049]

According to the present invention, there is provided an O / W / O type multi-layer emulsion in which a UV absorber is mixed in the inner oil phase, and the multi-layer emulsion suppresses the oxidation of the UV absorber by light or air. As a result, skin irritation is reduced, the feeling of use is good, and it can be used by people who were more sensitive to the stimulation of UV absorbers than before and could not use sunscreen agents. It will be possible.
In addition, by adding a water-soluble drug that is easily oxidized by light or air to the water phase of the O / W / O preparation, the oxidation can be efficiently suppressed and a higher stabilizing effect can be obtained.

Claims (1)

[Claims] 1. A multi-layer emulsion of O / W / O type, wherein an ultraviolet absorber is blended in the inner oil phase.