JP6758043B2 - Oil-in-water emulsified composition - Google Patents

Description

The present invention relates to an oil-in-water emulsified composition suitable for external preparations for skin.

The emulsifier type is used as a dosage form for external preparations for skin such as emulsions and creams, and the oil-in-water emulsifier type is particularly preferred because it provides a fresh feeling of use.

Emulsion is an unstable dispersion system with high energy state. Therefore, in order to stably disperse the emulsified particles in the outer phase, a method of lowering the interfacial tension by using a surfactant is usually adopted for the preparation of the emulsifier type. At that time, the HLB (Hydrophilic-Lypophilic Balance) value of the surfactant is used as an index of emulsification, and its adjustment depends largely on the experience of skill.
In addition, for stable emulsification, a total amount of 2 to 5% by mass of a surfactant is generally used with respect to the entire composition.

By the way, in recent years, "gemini-type ionic surfactant" has been used for the preparation of emulsifier type. The gemini-type ionic surfactant has a dimer structure in which a general ionic surfactant is linked by a linking group, and has a higher surface activating ability than the original single ionic surfactant. Are known. Various emulsifier-type cosmetics utilizing such high surface-activating ability have been proposed (Patent Documents 1, 2, etc.).

Japanese Unexamined Patent Publication No. 2014-73991 Japanese Unexamined Patent Publication No. 2013-1698

Since it is necessary to use an appropriate surfactant for the preparation of the emulsifier type, there are many matters to be considered such as adjustment of HLB and content, compatibility with oils, etc., so stable emulsion production can be easily achieved. There is no standard guideline yet.
In view of such a situation, it is an object of the present invention to provide an oil-in-water emulsified composition which is excellent in time and temperature stability and exhibits a good usability.

As a result of diligent research to solve the above problems, the present inventors have been able to produce a finer emulsion by combining the acyl amino acid lysine and / or a salt thereof with a specific surfactant. , The present invention has been completed by finding that the above problems can be solved.

That is, the present invention is as follows.
[1] The polyglycerin fatty acid ester containing (A) acyl amino acid lysine and / or a salt thereof, and (B) surfactin and a salt thereof, mannosyl erythritol lipid, and one or more selected from polyglycerin fatty acid esters. Is an oil-in-water emulsified composition which is an ester of a fatty acid having 12 to 18 carbon atoms and glycerin having a degree of polymerization of 4 to 6.
[2] The oil-in-water emulsified composition according to [1], wherein the total content of (A) is 0.01 to 5% by mass with respect to the entire composition.
[3] The oil-in-water emulsified composition according to [1] or [2], wherein the total content of (B) is 0.01 to 10% by mass with respect to the entire composition.
[4] The water according to any one of [1] to [3], wherein the mass ratio of the total content of (A) to the total content of (B) is 9: 1 to 1: 9. Oil-type emulsified composition.
[5] The oil-in-water emulsified composition according to any one of [1] to [4], which is an external preparation for skin.
[6] The oil-in-water emulsified composition according to [5], which is a cosmetic.

INDUSTRIAL APPLICABILITY The present invention provides an oil-in-water emulsified composition which is excellent in time and temperature stability and exhibits a good usability. In addition, when preparing an emulsion, the formulation components can be selected without excessively imposing complicated adjustments on the HLB and content of the surfactant, compatibility with the oil agent, and the like. Furthermore, since the content of the surfactant can be reduced while imparting excellent stability and a good feeling of use to the composition, the degree of freedom of prescription is improved, and the safety and health of consumers are conscious. You can also appeal.

The oil-in-water emulsified composition of the present invention is one or more selected from (A) acylamino acid lysine and / or a salt thereof, (B) surfactin and a salt thereof, mannosyl erythritol lipid, and a specific polyglycerin fatty acid ester. And contains.
The present invention is in that an oil-in-water emulsified composition which is excellent in time and temperature stability and exhibits a good usability can be easily prepared by a method of combining the surfactants (A) and (B). It is epoch-making.

The component (A), which is an essential component in the present invention, is the acyl amino acid lysine and / or a salt thereof.
As the acyl amino acid lysine in the present invention, lysine diacylglutamate whose acyl group is derived from fatty acid is preferable, and lysine dilauroyl glutamate, lysine dimyristyl glutamate, lysine distearoyl glutamate, lysine dilinole oil glutamic acid and the like are preferably mentioned.
Examples of these salts include alkali metal salts such as sodium salt and potassium salt, organic amine salts such as triethanolamine salt, and basic amino acid salts such as arginine.
Acylamino acid lysine or a salt thereof can be obtained by a synthetic reaction of lysine hydrochloride and acylamino acid anhydride. Moreover, a commercially available product can also be used.

The component (B), which is an essential component in the present invention, is one or more selected from surfactin and a salt thereof, mannosyl erythritol lipid, and a specific polyglycerin fatty acid ester. Of these, one or more selected from surfactin and salts thereof, and mannosyl erythritol lipid are preferable.

Surfactin is a so-called biosurfactant and cyclic peptide 2-Deamino-3- (10-methylundecyl) -cyclo [L-Ser * -L-Glu-L-Leu-D-Leu-L-Val-L. -Asp-D-Leu-L-Leu-]. As the salt of surfactin, a sodium salt can be preferably used in the present invention.

Mannosyl erythritol lipid (MEL) is also a biosurfactant, and any of MEL-A, B, C, and D can be used in the present invention, with MEL-B being more preferred.

The polyglycerin fatty acid ester that can be used as the component (B) in the present invention is an ester of a fatty acid having 12 to 18 carbon atoms and glycerin having a degree of polymerization of 4 to 6. The number of carbon atoms of the fatty acid is preferably 12 to 16. The fatty acid may be either a branched chain or a linear fatty acid, and may be either a saturated fatty acid or an unsaturated fatty acid. The number of fatty acids added is not particularly limited and may be mono-, di-, tri-, or more, but monoester is preferable.
The HLB value of the surfactant of the polyglycerin fatty acid ester is not particularly limited, but those of 3 to 18 are preferable. In this specification, the HLB value refers to a value calculated from Griffin's formula.
Further, it is preferable that the critical filling parameter (CPP) representing the geometric ratio of the hydrophilic part and the hydrophobic part of the amphipathic substance is 1/2 to 1.
Particularly preferred examples of the polyglycerin fatty acid ester include polyglyceryl-5 monooleate, polyglyceryl-6 monolaurate, polyglyceryl-4 monolaurate, polyglyceryl monopalmitate-6, polyglyceryl dilaurate-6 and the like.

In the present invention, the total content of the component (A) is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass, and further preferably 0.05 to 2% by mass with respect to the entire composition. It is mass%. Further, in the present invention, the total content of the component (B) is preferably 0.01 to 10% by mass, more preferably 0.01 to 3% by mass, and further preferably 0.05 with respect to the entire composition. ~ 2% by mass.
Further, the total content of the components (A) and (B) is preferably 0.02 to 11% by mass, more preferably 0.02 to 6% by mass, still more preferably, with respect to the entire composition. Is 0.06 to 4% by mass. If it is less than 0.02% by mass, the emulsion stability may be impaired, and if it is more than 11% by mass, a film feeling may be produced when the produced composition is applied to the skin. Further, as shown in Examples described later, the oil-in-water emulsified composition of the present invention has a time and temperature even when the total content of the components (A) and (B) is 1% by mass. It has excellent stability and a good usability. This is useful in the present invention because the content of the surfactant can be reduced as compared with the content of the surfactant in a general oil-in-water emulsified composition of 2 to 5% by mass. Represents sex.
Further, in the present invention, the mass ratio of the total content of the component (A) to the total content of the component (B) is preferably 9: 1 to 1: 9, and more preferably 8: 2 to 2: 8. Is. By using a surfactant having two different properties in combination in such a mass ratio, it becomes easier to form finer emulsified particles, and it becomes easier to improve the time and temperature stability of the oil-in-water emulsified composition. ..

The oil-in-water emulsified composition of the present invention can be produced according to a conventional method.
For example, the surfactant, the aqueous phase component, and the oil phase component of the component (A) and the component (B) may be stirred and mixed in an appropriate order to form an emulsion. At that time, heating to about 40 to 80 ° C. is preferable for homogenization.

The internal phase of the oil-in-water emulsified composition of the present invention is composed of oil phase components.
The oily component is usually composed of an oily component, and the oily component is not limited to so-called oily agents, but is a component that is suspended in water at 25 to 65 ° C. and allowed to stand for 1 hour, and then phase-separated from water (excluding surfactants). Point to.
Oily components that can be blended in the oil-in-water emulsified composition of the present invention include polar oils having polarity and non-polar oils having no polarity. Examples of polar oils include synthetic polar oils, natural oils, oil-soluble vitamins such as vitamins A and E, and examples of non-polar oils include hydrocarbon oils and silicone oils. Silicone oil may have polarity depending on its chemical structural formula. According to the present invention, all oil phase components can be stably emulsified.

Synthetic polar oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate. , Lanolin acetate, Isocetyl stearate, Isocetyl isostearate, Cholesteryl 12-hydroxystearyl, Ethylene glycol di-2-ethylhexylate, Dipentaerythritol fatty acid ester, N-alkylglycol monoisostearate, Neopentyl glycol dicaprate, Appleic acid Diisostearyl, glyceryl di-2-heptyl undecanoate, trimethylol propane tri-2-ethylhexylate, trimethylol propane triisostearate, pentanerythritol tetra-2-ethylhexylate, glyceryl tri-2-ethylhexylate, triisostearic acid Trimethylol propane can be mentioned. In addition, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, glyceride tri-2-heptyl undecanoic acid, castor oil fatty acid methyl ester, oleic acid oil, cetostearyl alcohol, acetoglyceride, palmitic acid 2 -Heptylundecyl, diisobutyl adipate, N-lauroyl-L-glutamic acid-2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyllaurate, di-2-ethylhexyl sebatate, 2-hexyl myristate Examples thereof include decyl, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebatate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, triethyl citrate, and octylmethoxycinnamate.

Also, as natural oils, avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, southern ka oil, castor oil, flaxseed oil, Saflower oil, cotton seed oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnamon oil, Japanese millet oil, jojoba oil, germ oil, glyceryl trioctanoate, glyceryl triisopalmitate, tri ( Caprylic acid / capric acid) Glyceryl and the like can be mentioned. Examples of the hydrocarbon oil include isododecane, isohexadecane, squalane, petrolatum, hydrogenated poly (C6-12 olefin), hydrogenated polyisobutene and the like. Examples of the non-polar silicone oil include cyclopentasiloxane, decamethylcyclopentasiloxane, caprylylmethicone, dimethicone, (dimethicone / vinyldimethicone) crosspolymer, (dimethicone / phenylvinyldimethicone) crosspolymer and the like. Examples of the polar silicone oil include diphenylsiloxyphenyltrimethicone.

In the oil-in-water emulsified composition of the present invention, the content of the oil phase component is preferably 1 to 75% by mass, more preferably 3 to 50% by mass, and further preferably 5 to 30% by mass with respect to the entire composition. Add so that Further, it can be emulsified even if the proportion of polar oil is large, and it can be emulsified even if the proportion of polar oil in the oil phase component is 80% or more, and it can be emulsified even if it is 60% or more. Within such a range, it can be an oil-in-water emulsified composition excellent in time and temperature stability, and can be a skin external preparation exhibiting a good feeling of use.

The outer phase of the oil-in-water emulsified composition of the present invention is composed of an aqueous phase component.
The aqueous phase component is usually a water-soluble component in addition to water, and refers to a component (excluding surfactants) that dissolves in water after being suspended in water at 25 to 65 ° C. and allowed to stand for 1 hour.

It is preferable to contain a polyhydric alcohol as the aqueous phase component. By containing the polyhydric alcohol, the temperature and temporal stability of the oil-in-water emulsified composition can be further improved.
In the present invention, the content of the polyhydric alcohol is preferably 1 to 50% by mass, more preferably 10 to 40% by mass, and further preferably 25 to 35% by mass with respect to the entire composition.
If the content of the polyhydric alcohol is less than 1% by mass, it may be difficult to obtain emulsion stability, while if it is more than 50% by mass, a refreshing feel is obtained when the oil-in-water emulsified composition is applied to the skin. It may be difficult to get rid of.

The polyhydric alcohol is not particularly limited as long as it is divalent or higher, but trihydric or higher is preferable.
Specifically, divalent alcohols (eg, ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, tetramethylene glycol, 2,3-butylene glycol, pentamethylene glycol). , 2-Buten-1,4-diol, hexylene glycol, octylene glycol, etc.; trivalent alcohols (eg, glycerin, trimethylolpropane, etc.); tetravalent alcohols (eg, 1,2,6-hexanetriol, etc.) Pentaerythritol, etc.); pentavalent alcohol (eg, xylitol, etc.); hexavalent alcohol (eg, sorbitol, mannitol, etc.); polyhydric alcohol polymers (eg, diethylene glycol, dipropylene glycol, triethylene glycol, polypropylene glycol, etc.) Tetraethylene glycol, diglycerin, polyethylene glycol, triglycerin, tetraglycerin, polyglycerin, etc.; divalent alcohol alkyl ethers (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol mono) Phenyl ether, ethylene glycol monohexyl ether, ethylene glycol mono2-methylhexyl ether, ethylene glycol isoamyl ether, ethylene glycol benzyl ether, ethylene glycol isopropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, etc.); 2 Valuable alcohol alkyl ethers (eg, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol butyl ether, diethylene glycol methyl ethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene Glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol isopropyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, etc. ); Dihydric alcohol ether ester (eg, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, ethylene glycol diazibate, ethylene glycol disuccinate, diethylene glycol mono Ethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monophenyl ether acetate, etc.); glycerin monoalkyl ether (eg, xyl alcohol, ceracyl) Alcohols, batyl alcohols, etc.); Sugar alcohols (eg, sorbitol, martitol, maltotriose, mannitol, sucrose, erythritol, glucose, fructose, starch-degrading sugar, maltose, xylitos, starch-degrading sugar-reducing alcohol, etc.); Tetrahydrofurfuryl alcohol; POE-tetrahydrofurfuryl alcohol; POP-butyl ether; POP / POE-butyl ether; tripolyoxypropylene glycerin ether; POP-glycerin ether; POP-glycerin ether phosphoric acid; POP / POE-pentaneerythritol ether And so on.
Of these, glycerin, diglycerin, dipropylene glycol, and polyethylene glycol having a molecular weight of 600 or less are more preferable, and glycerin is particularly preferable.

In addition, the oil-in-water emulsified composition of the present invention may contain other optional components as long as its effect is not impaired.
The optional component is not particularly limited as long as it is a component that can be usually blended with an external preparation for skin, and other surfactants (cationic surfactant, anionic surfactant, nonionic surfactant, silicone-based surfactant). Activators, etc.), various active ingredients, moisturizers, pH regulators, thickeners, preservatives, powders, organically modified clay minerals, antibacterial agents, etc. Examples of the antibacterial agent include synthetic systems such as 1,3-butylene glycol and paraoxybenzoic acid ester, as well as natural antibacterial substances such as caprylyl glycol, glyceryl caprylate, ethylhexyl glycerin and capryl hydroxamic acid. As the surfactant, those having no ethylene oxide (EO) group are preferable.
Examples of the active ingredient include a moisturizing ingredient, a whitening ingredient, a wrinkle improving ingredient, an anti-inflammatory ingredient, an extract derived from animals and plants, and the like, and may contain only one kind, or may contain two or more kinds.

The oil-in-water emulsified composition of the present invention is excellent in time and temperature stability because fine emulsified particles are stably dispersed in the outer phase. In addition, when applied to the skin, it does not give a film feeling, a refreshing feel is obtained, and the skin can be given a soft feeling, so that a good usability is exhibited.
Therefore, the oil-in-water emulsified composition of the present invention can be preferably used as an external preparation for skin. In particular, cosmetics (including quasi-drugs) are preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded.

The oil-in-water emulsified compositions of Examples and Comparative Examples were prepared according to the formulations shown in Table 1, respectively. Specifically, a, b, and c were heated to 80 ° C. to homogenize each of them, and b was added to the mixture of a and c, and then cooled to 30 ° C. with stirring.

<Test Example 1> Evaluation of Emulsified Particle Size Each of the oil-in-water emulsified compositions of the above Examples and Comparative Examples was left at 20 ° C. for 1 day after preparation, and then observed with an optical microscope (OLYMPUS BX51). The size and uniformity were evaluated in the following four stages. The results are shown in Table 1.
⊚: The emulsified particles are small (1 μm or less) and uniform.
◯: The emulsified particles are small (1 μm or less) but non-uniform.
Δ: The emulsified particles are large (more than 1 μm) but uniform.
X: The emulsified particles are large (more than 1 μm) and non-uniform.

<Test Example 2> Evaluation of time and temperature stability After each of the oil-in-water emulsified compositions of the above Examples and Comparative Examples was placed at 40 ° C. for 1 month after preparation, changes in state such as phase separation and creaming were visually observed. The presence or absence was observed. The results are shown in Table 1.

<Test Example 3> Usability Evaluation Each of the oil-in-water emulsified compositions of the above Examples and Comparative Examples was used on the skin by 20 female subjects, and the feeling of use (stickiness and softness) was as follows. I was evaluated in stages. The average value of 20 people is shown in Table 1 as the evaluation result.
(A feeling of stickiness)
5: Not sticky at all 4: Almost not sticky 3: Not very sticky 2: Sticky 1: Very sticky (flexibility)
5: Very feel 4: Feel 3: Slightly feel 2: Not feel (slightly hard)
1: I don't feel it at all (hard)

INDUSTRIAL APPLICABILITY The present invention provides an oil-in-water emulsified composition which is excellent in time and temperature stability and exhibits a good usability. Further, since the content of the surfactant can be reduced, the degree of freedom of formulation can be improved, and the oil-in-water emulsified composition can be appealed to consumers for safety and health. Therefore, the oil-in-water emulsified composition of the present invention can be suitably used as an external preparation for skin and the like, and is particularly suitable as a cosmetic, and is therefore very useful in industry.

Claims (3)

(A) Acyl amino acid lysine and / or a salt thereof,
(B) An oil-in-water emulsified composition containing mannosyl erythritol lipid. The oil-in-water emulsified composition according to claim 1, wherein the total content of (B) is 0.01 to 10% by mass with respect to the entire composition. The oil-in-water emulsified composition according to claim 1 or 2 , wherein the mass ratio of the total content of (A) to the total content of (B) is 9: 1 to 1: 9.