CN117881384A - Skin external preparation containing 12-hydroxystearic acid and having bicontinuous microemulsion structure - Google Patents

Abstract

The purpose of the present invention is to provide a gel-like or solid external skin preparation which has sufficient viscosity, hardness and stability while maintaining the original detergency of a bicontinuous microemulsion. The external preparation for skin of the present invention is characterized by comprising: the skin external preparation has a bicontinuous microemulsion structure and is gel-like or solid, and (A) water, (B) a water-soluble organic solvent, (C) a surfactant, (D) an oil component, and (E) 12-hydroxystearic acid.

Description

Skin external preparation containing 12-hydroxystearic acid and having bicontinuous microemulsion structure

Technical Field

The present invention relates to a skin external preparation having a bicontinuous microemulsion structure. More specifically, the present invention relates to a gel-like or solid external preparation for skin which contains 12-hydroxystearic acid, has sufficient viscosity, hardness and stability while maintaining the original detergency of a bicontinuous microemulsion, and can prevent dripping and is excellent in handling properties.

Background

Cleansing cosmetics are generally classified broadly into oily cleansing cosmetics and aqueous cleansing cosmetics. Since oily cleansing cosmetics contain a large amount of oily components, they have excellent cleansing power due to good fusion with makeup dirt, but have a remarkable sticky feeling due to the oily components and poor feeling in use. On the other hand, the amount of oily components blended in the aqueous cleansing cosmetic is small, and therefore, the aqueous cleansing cosmetic has a fresh feel in use, but tends to be poor in fusion with makeup dirt and poor in detergency.

Thus, as a technique for achieving these advantages, many cleansing cosmetics having a bicontinuous microemulsion structure (isotropic surfactant continuous phase) in which a continuous phase is formed from an oil phase and an aqueous phase have been proposed.

For example, patent document 1 discloses a cleaning agent composition comprising an amphoteric surfactant and an anionic surfactant in a specific ratio, and further comprising a liquid alcohol and/or a liquid fatty acid and water, and is considered to have excellent cleaning ability by forming an isotropic surfactant continuous phase, that is, a bicontinuous phase.

Patent document 2 discloses a cleansing product which contains a nonionic surfactant, a polar oil, a silicone oil, and water in a specific blending amount, and which has an isotropic surfactant continuous phase, so that the cleansing product has excellent fusion with makeup and a high cleansing effect.

Bicontinuous microemulsions are layers of aqueous components and layers of oily components that are three-dimensionally intricately formed into two continuous structures, exhibiting optically isotropic, transparent, one-liquid phase properties. By using the bicontinuous microemulsion in a cleansing cosmetic, the surface tension of oil/water becomes small and the fusion with makeup dirt becomes good, a high cleansing performance can be obtained, and the continuous phase becomes oil and water and the cleansing effect of the makeup dirt is excellent and a fresh feeling of use can be obtained.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2002-20791

Patent document 2: japanese patent laid-open No. 2000-256132

Disclosure of Invention

Problems to be solved by the invention

However, the skin external preparation having a bicontinuous microemulsion structure is low in viscosity and has fluidity as high as that of a liquid, and thus, is inferior in operability such as generation of dripping at the time of application. In addition, when the components are different, phase separation may occur between the aqueous phase and the oil phase if the temperature is deviated from an appropriate temperature, resulting in poor stability.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a gel-like or solid external preparation for skin having sufficient viscosity, hardness and stability while maintaining the original detergency of a bicontinuous microemulsion.

Solution for solving the problem

The present inventors have conducted intensive studies to solve the above problems, and as a result, found that: by compounding 12-hydroxystearic acid, sufficient viscosity or hardness and stability can be obtained while having a bicontinuous microemulsion structure, thus completing the present invention.

That is, the gist of the present invention is to provide a gel-like or solid external skin preparation comprising:

(A) Water, water,

(B) A water-soluble organic solvent,

(C) A surfactant (S),

(D) Oil content and

(E) 12-hydroxy-stearic acid,

the skin external agent has a bicontinuous microemulsion structure.

ADVANTAGEOUS EFFECTS OF INVENTION

By adopting the technical scheme, the skin external preparation provided by the invention can realize the skin external preparation with sufficient viscosity, hardness and stability and a bicontinuous microemulsion structure. This is thought to be because 12-hydroxystearic acid enters the molecular film of the surfactant arranged between the oil layer and the water layer like a wedge, physically supporting the structure.

The external skin preparation of the present invention has a bicontinuous microemulsion structure but is in a gel or solid state, and thus can achieve excellent detergency and handleability.

Detailed Description

The external skin preparation of the present invention comprises:

(A) Water, water,

(B) A water-soluble organic solvent,

(C) A surfactant (S),

(D) Oil content and

(E) 12-hydroxystearic acid.

The following is a detailed description.

Hereinafter, polyoxyethylene may be referred to simply as "POE", polyoxypropylene may be referred to simply as "POP", and polyethylene glycol may be referred to simply as "PEG".

Water < (A)

The water (a) to be blended in the present invention (hereinafter, sometimes referred to as "component (a)") is not particularly limited, and purified water, ion-exchanged water, distilled water, or the like can be used.

(A) The amount of water to be blended is not particularly limited, but is preferably 10 to 70% by mass, more preferably 20 to 50% by mass, based on the total amount of the external preparation for skin. When the amount is less than 10% by mass, the feeling of use of the composition with water may not be obtained, and when the amount exceeds 70% by mass, the stability and the cleaning property of the preparation may be deteriorated.

(B) Water-soluble organic solvent ]

The water-soluble organic solvent (B) blended in the present invention (hereinafter, sometimes referred to as "component (B)") affects the association state of the surfactant (C), and can increase the solubilization amount of the oil component (D) and the 12-hydroxystearic acid (E) in the hydrophobic portion of the surfactant (C).

As the water-soluble organic solvent (B), a lower alcohol, a polyhydric alcohol or a block alkylene oxide derivative is preferably used.

Examples of the lower alcohol include ethanol, propanol, isopropanol, butanol, and the like.

Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1, 3-butanediol, 1, 4-butanediol, 1, 2-pentanediol (pentanediol), 1, 5-pentanediol, neopentyl glycol, 1, 2-hexanediol, 1, 6-hexanediol, 1, 2-cyclohexanediol, heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, glycerin, pentaerythritol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, and the like.

Examples of the block alkylene oxide derivatives include random or block copolymer dimethyl ethers of polyoxyethylene and polyoxypropylene (in this specification, the numbers in brackets after POE and POP represent the molar numbers of addition), such as POE (9) POP (2) dimethyl ether, POE (14) POP (7) dimethyl ether, POE (10) POP (10) dimethyl ether, POE (6) POP (14) dimethyl ether, POE (7) POP (14) dimethyl ether, POE (17) POP (4) dimethyl ether, and the like (in this specification, these may be simply referred to as "POE/POP dimethyl ether").

Particularly preferred (B) water-soluble organic solvents are 1 or more selected from the group consisting of dipropylene glycol, 1, 3-butanediol, 1, 2-pentanediol, POE/POP dimethyl ether, polyethylene glycol and glycerin. These may be used alone or in combination of 2 or more.

(B) The amount of the water-soluble organic solvent to be blended is not particularly limited, but is preferably 3 to 60% by mass, more preferably 10 to 30% by mass, based on the total amount of the external preparation for skin. When the blending amount is less than 3% by mass, a bicontinuous microemulsion structure may not be obtained, and when the blending amount exceeds 60% by mass, stability and cleaning performance of the preparation may be deteriorated.

(C) surfactant

The surfactant (C) to be blended in the present invention (hereinafter, sometimes referred to as "component (C)") is not particularly limited as long as it can form a bicontinuous microemulsion structure, but among them, a hydrophilic nonionic surfactant is preferable.

The surfactant (C) is preferably 1 or more selected from the group consisting of polyethylene glycol fatty acid esters, polyethylene glycol alkyl ethers, polyethylene glycol alkylphenyl ethers, polyethylene glycol castor oil derivatives, polyethylene glycol hydrogenated castor oil derivatives, and ethylene oxide derivatives of glycerol fatty acid esters, for example.

Specifically, polyethylene glycol distearate, polyethylene glycol monooleate, ethylene glycol distearate, polyethylene glycol lauryl ether, PEG-10 hydrogenated castor oil, PEG-8 glycerol isostearate, PEG-7 glycerol cocoate, PEG-20 glycerol triisostearate, PEG-60 glycerol isostearate, and the like can be cited.

In the case of blending a plurality of surfactants having different HLB values as the surfactant (C), the average HLB is preferably 8.5 to 14, more preferably 9 to 12. In the present specification, "average HLB" means a weighted average.

(C) The amount of the surfactant to be blended is not particularly limited, but is preferably 10 to 45% by mass, more preferably 20 to 40% by mass, based on the total amount of the external preparation for skin. If the amount is less than 10% by mass, the detergency will be low, and if it exceeds 45% by mass, the composition will be sticky when used.

Oil (D)

The oil component (D) (hereinafter, sometimes referred to as "component (D)") to be blended in the present invention is not particularly limited, and various oil components widely used in external preparations for skin can be blended. Among them, 1 or more selected from the group consisting of liquid oils and fats, hydrocarbon oils, ester oils, and silicone oils is preferable.

Specifically, there may be mentioned avocado oil, evening primrose oil, camellia seed oil, turtle oil, macadamia nut (MACADAMIA INTEGRIFOLIA) seed oil, sunflower (HELIANTHUS ANNUUS) seed oil, sweet almond (PRUNUS AMYGDALUS DULCIS) oil, corn oil, mink oil, olive (Olea EUROPAEA) fruit oil, rapeseed oil, egg oil, sesame oil, peach kernel oil, wheat germ oil, camellia oil, castor oil, linseed oil, safflower oil, cottonseed oil, perilla oil, soybean oil, peanut oil, tea seed oil, torreya oil, rice bran oil, jatropha oil, japanese tung oil, jojoba (SIMMONDSIA CHINENSIS) seed oil, germ oil and other liquid oils; hydrocarbon oils such as isododecane, liquid paraffin, squalene, pristane, and polybutene; ethylhexyl palmitate, cetyl octanoate, ethyl 2-acetate, hexyl dimethyloctanoate, ethyl laurate, hexyl laurate, isopropyl myristate, 2-hexyl decyl myristate, myristyl myristate, octyl dodecanol myristate, isopropyl palmitate, 2-ethylhexyl palmitate, isocetyl palmitate, 2-heptyl undecyl palmitate, butyl stearate, isocetyl isostearate, decyl oleate, dodecyl oleate, oil oleate, myristyl lactate, cetyl lactate, diisostearyl malate, cholesterol 12-hydroxystearate, methyl ricinoleate, 2-ethylhexyl succinate, diisobutyl adipate, 2-hexyl decyl adipate, di (heptyl undecyl) adipate, diisopropyl sebacate, di (2-ethylhexyl) sebacate, ethylene glycol di (2-ethylhexyl) undecyl palmitate, neopentyl glycol dicaprate, neopentyl glycol di (ethyl caproate), acetyl glyceride, diisostearyl glyceride, triisocaprylate, triglyceryl glyceride, triglyceryl palmitate, triglyceryl 2-hydroxyethyl stearate, triglyceryl (2-ethylhexyl) isocyanurate, triglyceryl palmitate, triglyceryl (2-methyl) isopropyl myristate, triglyceryl stearate, triglyceryl (2-ethyl-hydroxyethyl) myristate, triglyceryl stearate, and the like; silicone oils such as chain polysiloxanes such as dimethylpolysiloxane, polymethylphenylsiloxane, diphenylpolysiloxane, cyclic polysiloxanes such as octamethyl cyclotetrasiloxane, cyclopentadimethicone, and dodecamethyl cyclosiloxane, and various modified polysiloxanes such as amino-modified polysiloxanes, polyether-modified polysiloxanes, alkyl-modified polysiloxanes, and fluorine-modified polysiloxanes.

(D) The amount of the oil to be blended is not particularly limited, but is preferably 5 to 25% by mass, more preferably 10 to 20% by mass, based on the total amount of the skin external preparation. When the amount is less than 5% by mass, the cleaning effect may be reduced, and when the amount exceeds 25% by mass, the stability of the preparation may be deteriorated.

Selection condition of preferred combination of (B), (C) and (D)

The combination of (B) the water-soluble organic solvent, (C) the surfactant and (D) the oil component blended in the skin external agent of the present invention is preferably selected so as to satisfy the following conditions (i) and (ii):

(i) When preparing a mixture of (A) water, (B) a water-soluble organic solvent, (C) a surfactant and (D) an oil component, a 1-phase system of either one of a liquid crystal phase and an isotropic surfactant continuous phase formed by a surfactant association or a coexistence system of either one of the liquid crystal phase and the isotropic surfactant continuous phase and the other phase is formed;

(ii) The viscosity of the mixture at 25 ℃ is below 250 mPas.

Condition (i) >

Among the essential components blended in the skin external preparation of the present invention, the mixture composed of (E) 12-hydroxystearic acid, namely, only (a) water, (B) a water-soluble organic solvent, (C) a surfactant and (D) an oil component is preferably formed into a 1-phase system of a liquid crystal phase or an isotropic surfactant continuous phase or into a coexisting system of a liquid crystal phase and an isotropic surfactant continuous phase. An excellent cleaning effect can be obtained if the combination of (B) a water-soluble organic solvent, (C) a surfactant, and (D) an oil component is used to satisfy this condition.

The blending ratio of each component in the mixture is preferably the same as that of each component in the external preparation for skin. Specifically, the total amount of the mixture is preferably (A) 20 to 50% by mass of water, (B) 10 to 30% by mass of a water-soluble organic solvent, (C) 20 to 40% by mass of a surfactant, and (D) 10 to 20% by mass of an oil component.

Whether the mixture forms a liquid crystal phase and/or an isotropic surfactant continuous phase can be typically determined by a known method such as a light transmission test based on a polarizing plate, a dispersion test of aqueous and oily pigments, transmission electron microscope observation, and conductivity measurement at a temperature of 25 ℃.

Since the liquid crystal phase is optically anisotropic, the isotropic surfactant continuous phase can be distinguished by a light transmission test by a polarizing plate.

Condition (ii) >

The mixture composed of (A) water, (B) a water-soluble organic solvent, (C) a surfactant and (D) an oil component preferably has a viscosity of 250 mPas or less at 25 ℃. A combination of (B) a water-soluble organic solvent, (C) a surfactant and (D) an oil component to satisfy the viscosity can provide good detergency.

The "viscosity" of the mixture is a value measured at 25℃for 30 minutes or longer using a B-type viscometer under the conditions of rotor No.2, rotation speed of 30rpm and 1 minute.

(E) 12-hydroxystearic acid ]

The (E) 12-hydroxystearic acid (hereinafter sometimes referred to as the "(E) component") blended in the present invention is hydrogenated in ricinoleic acid, and is a saturated fatty acid having an asymmetric hydroxyl group in the carbon at the 12-position. The hydrogenated castor oil obtained by hydrogenating castor oil may be hydrolyzed or hydrogenated castor oil fatty acid obtained by hydrolyzing castor oil may be obtained by hydrogenating castor oil.

(E) The 12-hydroxystearic acid gels the skin external preparation of the present invention to impart sufficient viscosity, hardness and stability, but unlike general thickeners, does not cause wetting or tackiness. This is considered to be because (E) 12-hydroxystearic acid enters the molecular film of the surfactant arranged between the oil layer and the water layer like a wedge, and the three-dimensionally entered water layer is connected to the oil layer to physically support the bicontinuous microemulsion structure.

(E) The amount of 12-hydroxystearic acid to be blended is necessarily 0.5 to 10% by mass, more preferably 1 to 5% by mass, based on the total amount of the external preparation for skin. When the amount is less than 0.5% by mass, a sufficient gelation effect may not be obtained, and when it exceeds 10% by mass, a solid may be formed, and the handleability may be deteriorated.

< arbitrary ingredients >

The external preparation for skin of the present invention may contain components which are usually used for external preparation for skin, in addition to the components (a) to (E), within a range which does not impair the effects of the present invention. For example, a cleaning component such as an anionic surfactant, a chelating agent, a preservative, an antioxidant, a powder, a perfume, a colorant, a coloring matter, and the like may be appropriately blended as needed.

Structure of bicontinuous microemulsion

The skin external preparation of the present invention has a bicontinuous microemulsion structure. Whether or not the structure of the bicontinuous microemulsion is present can be determined by a known method such as a light transmission test by a polarizing plate, a dispersion test of an aqueous and oily dye, and a transmission electron microscope observation of a sample prepared by a freeze-cut replication method.

The skin external preparation of the present invention has a viscosity at 25℃of 400 mPas or more, preferably 1000 to 100000 mPas, more preferably 2000 to 30000 mPas, or a hardness (rheometer) at 25℃of 5 to 500gf, preferably 5 to 400gf, more preferably 5 to 300gf. The viscosity is an index when the external preparation for skin is in a liquid to gel state, and the hardness is an index when the gelation of the external preparation for skin further progresses and exceeds the upper limit of the measurement of the viscosity, that is, in a gel to solid state.

By satisfying such conditions of viscosity and hardness, the external skin preparation is in a moderate gel or solid state, and exhibits excellent handleability without dripping.

< preparation method >)

As a method for producing a skin external preparation having a bicontinuous microemulsion structure, generally, a raw material that is solid at ordinary temperature is dissolved once, and then all components are uniformly mixed and cooled.

However, if the components (a) to (E) blended in the external skin preparation of the present invention are heated and mixed and cooled only, crystals of (E) 12-hydroxystearic acid may precipitate and separate, and thus proper viscosity and hardness may not be obtained.

In order to incorporate (E) 12-hydroxystearic acid into the bilayer membrane of surfactant disposed between the oil layer and the water layer to form a bicontinuous microemulsion structure with moderate viscosity or hardness and stability, it is necessary to first solubilize (E) 12-hydroxystearic acid in the hydrophobic portion of (C) surfactant, then mix with water and cool.

The specific production method preferably includes the following steps (i) to (iii):

(i) A step of heating (B) a water-soluble organic solvent, (C) a surfactant, (D) an oil component, and (E) 12-hydroxystearic acid to 60 to 90 ℃ and uniformly dissolving them to prepare an intermediate composition;

(ii) A step of adding the intermediate composition obtained in the step (i) to an aqueous medium containing (a) water while stirring to prepare a mixture, or a step of adding an aqueous medium containing (a) water to the intermediate composition obtained in the step (i) while stirring to prepare a mixture; and

(iii) And (c) cooling the mixture obtained in step (ii) to room temperature.

< usage >

The external skin preparation of the present invention can be used mainly as a cleanser, and is particularly preferably used as a cleanser or the like. The skin external agent of the present invention may be used by immersing a substrate such as nonwoven fabric to prepare a sheet-like cleansing composition for wiping off makeup dirt and sebum dirt.

Examples

The present invention will be further described in detail with reference to the following examples, but the present invention is not limited thereto. The amount to be blended is expressed as mass% of the system to be blended with the component unless otherwise specified. Before the embodiments are specifically described, the evaluation method employed will be described.

(1) Viscosity of the mixture

The viscosity of the prepared skin external preparation was maintained at 25℃for 30 minutes or more, and then measured using a B-type viscometer under the conditions of a rotor No.3, a rotation speed of 12rpm and 1 minute.

(2) Hardness of

For the hardness of the prepared skin external preparation after being kept at 25 ℃ for 30 minutes or more, the external preparation was subjected to load using a rheometer (Sun Scientific co., ltd.): 200g, measurement terminals: 8mm phi, needle penetration depth: 10mm, rise speed: 300 mm/min, determination temperature: measured at 25 ℃.

(3) Stability of

The prepared external preparation for skin was stored at 50℃for 1 month, and then the state of the external preparation for skin was visually observed, and the stability was evaluated according to the following criteria.

A: no crystal precipitation and/or phase separation was confirmed at all.

B: minimal crystal precipitation and/or phase separation were confirmed, but at a level at which there was no problem in use.

C: the crystal deposition and/or phase separation were confirmed to be unusable levels.

(4) Usability of the article

The skin external preparations of examples and comparative examples were used by 20 members of the cosmetic evaluation panelists, the usability (presence/absence of dripping and the degree of satisfactory handling) was evaluated in 5 stages according to the following criteria, and the average score of all the members was determined according to the following 3-stage criteria.

(evaluation criterion)

Evaluation results: scoring of

Very good: 5 minutes

Good: 4 minutes

Common: 3 minutes

Slightly bad: 2 minutes

The method is not good: 1 minute

(determination criterion)

And (3) judging: average score

A: more than 4

B:3 or more and less than 4

C: below 3

Examples 1 to 6 and comparative examples 1 to 2 >

External preparations for skin having the compositions shown in Table 1 were prepared, and the viscosity, hardness, stability and usability were evaluated by the evaluation methods described above.

TABLE 1

As shown in table 1 above, when (a) water, (B) a water-soluble organic solvent, (C) a surfactant, and (D) an oil component are contained and (E) 12-hydroxystearic acid is contained in the range of 0.5 to 10 mass%, a bicontinuous microemulsion structure can be formed and excellent stability and usability can be obtained (examples 1 to 6). On the other hand, when (E) 12-hydroxystearic acid was not blended, dripping occurred, and usability was significantly deteriorated (comparative example 1). If the amount of (E) 12-hydroxystearic acid blended is too large, the crystallinity becomes strong, and both stability and usability are insufficient (comparative example 2). In comparative example 2, since the formation of the bicontinuous microemulsion structure was not observed, and crystal deposition was confirmed, the measurement of viscosity and hardness was not performed.

Examples 7 to 9 and comparative example 3 >, respectively

External preparations for skin having the compositions shown in Table 2 were prepared, and the viscosity, stability and usability were evaluated by the evaluation methods described above.

TABLE 2

As shown in table 2, the compositions of the surfactant (C) and the oil component (D) were changed to form a bicontinuous microemulsion structure, and sufficient stability and usability were obtained (examples 7 to 9). On the other hand, if the amount of the surfactant (C) blended is too small, phase separation occurs, and the stability and usability are deteriorated (comparative example 3). This is considered to be because the blending amount of the surfactant (C) is too small, and the oil content of the (E) 12-hydroxystearic acid and the (D) oil content is not sufficiently solubilized. In comparative example 3, the bicontinuous microemulsion structure was not formed, and phase separation occurred, so that the viscosity was not measured.

Examples 10 to 12 and comparative examples 4 to 5 >, respectively

External preparations for skin having the compositions shown in Table 3 were prepared, and the viscosity, stability and usability were evaluated by the evaluation methods described above.

TABLE 3

As shown in table 3, the composition of the surfactant (C) was changed within the range of 8.5 to 14, and the bicontinuous microemulsion structure was formed, and sufficient stability and usability were obtained (examples 10 to 12). On the other hand, if surfactants having average HLB of 8 and 16 were used, the (E) 12-hydroxystearic acid and (D) oil were not sufficiently solubilized and phase separation occurred (comparative examples 4 and 5). In comparative examples 4 and 5, a bicontinuous microemulsion structure was not formed, and phase separation occurred, so that viscosity was not measured.

Claims (8)

1. A gel-like or solid external preparation for skin comprising:

(A) Water, water,

(B) A water-soluble organic solvent,

(C) A surfactant (S),

(D) Oil content and

(E) 12-hydroxy-stearic acid,

the skin external agent has a bicontinuous microemulsion structure.

2. The external preparation for skin according to claim 1, wherein,

(B) The water-soluble organic solvent, (C) the surfactant and (D) the oil component satisfy the following conditions (i) and (ii):

(i) When preparing a mixture of (A) water, (B) a water-soluble organic solvent, (C) a surfactant and (D) an oil component, a 1-phase system of either one of a liquid crystal phase and an isotropic surfactant continuous phase formed by a surfactant association or a coexistence system of either one of the liquid crystal phase and the isotropic surfactant continuous phase and the other phase is formed;

(ii) The viscosity of the mixture at 25 ℃ is below 250 mPas.

3. The external preparation for skin according to claim 1, wherein the amount of (E) 12-hydroxystearic acid is 0.5 to 10% by mass based on the total amount of the external preparation for skin.

4. The external skin preparation according to claim 1, wherein the surfactant (C) is 1 or more nonionic surfactants selected from the group consisting of polyethylene glycol fatty acid esters, polyethylene glycol alkyl ethers, polyethylene glycol alkylphenyl ethers, polyethylene glycol castor oil derivatives, polyethylene glycol hydrogenated castor oil derivatives, and ethylene oxide derivatives of glycerin fatty acid esters.

5. The external preparation for skin according to claim 1, wherein the amount of the surfactant (C) is 10 to 45% by mass based on the total amount of the external preparation for skin, and the average HLB of the surfactant (C) is 8.5 to 14.

6. The external preparation for skin according to claim 1, wherein (B) the water-soluble organic solvent is 1 or more selected from the group consisting of dipropylene glycol, 1, 3-butanediol, 1, 2-pentanediol, POE/POP dimethyl ether, polyethylene glycol and glycerin.

7. The external preparation for skin according to claim 1, wherein the oil component (D) is 1 or more selected from the group consisting of liquid oils and fats, hydrocarbon oils, ester oils and silicone oils.

8. A method for producing the external preparation for skin according to claim 1, comprising the following steps (i) to (iii):

(i) A step of heating (B) a water-soluble organic solvent, (C) a surfactant, (D) an oil component, and (E) 12-hydroxystearic acid to 60 to 90 ℃ and uniformly dissolving them to prepare an intermediate composition;

(ii) A step of adding the intermediate composition obtained in the step (i) to an aqueous medium containing (a) water while stirring to prepare a mixture, or a step of adding an aqueous medium containing (a) water to the intermediate composition obtained in the step (i) while stirring to prepare a mixture; and

(iii) And (c) cooling the mixture obtained in step (ii) to room temperature.