WO2020213660A1 - O/d-type emulsion composition containing glycyrrhetinic acid, and oil-in-water-type emulsion composition - Google Patents

Abstract

An O/D-type emulsion composition containing glycyrrhetinic acid, the emulsion composition comprising (a) an oil comprising at least one of a higher alcohol and an ester oil, (b) a nonionic surfactant and (c) a polyhydric alcohol, wherein the ratio of the content of the nonionic surfactant (b) to the content of the oil (a), i.e., (b)/(a), is 0.26 to 3.5, the ratio of the content of the polyhydric alcohol (c) to the content of the nonionic surfactant (b), i.e., (c)/(b), is 0.75 to 6, and the content of water (d) is 0 to 15% by mass. The present invention also provides: a method for producing an O/D-type emulsion composition; an oil-in-water-type emulsion composition containing an O/D-type emulsion composition and a method for producing the oil-in-water-type emulsion composition; and an external preparation for skin, comprising an O/D-type emulsion composition or an oil-in-water-type emulsion composition. According to the O/D-type emulsion composition of the present invention, it becomes possible to produce an oil-in-water-type emulsion composition having glycyrrhetinic acid stably dispersed therein by adding a water-based medium to the O/D-type emulsion composition.

Description

O / D type emulsification composition containing glycyrrhetinic acid, oil-in-water emulsification composition

The present invention relates to an O / D type emulsified composition containing glycyrrhetinic acid and an oil-in-water emulsified composition containing the same. Furthermore, the present invention also relates to an external preparation for skin containing these O / D type emulsified compositions or oil-in-water emulsified compositions.

Β-Glycyrrhizic acid (hereinafter, simply referred to as "glycyrrhetinic acid") is an aglycone of glycyrrhizic acid obtained from the rhizome of licorice and the like, and is a compound obtained by hydrolyzing glycyrrhizic acid. Glycyrrhetinic acid is known to have useful actions such as anti-inflammatory action and whitening action, and is blended in many skin cosmetics by utilizing the actions (for example, Non-Patent Document 1).

Shigeru Sekine et al., New Cosmetics Handbook, Nikko Chemicals Co., Ltd. et al., October 30, 2006, pp. 575-577

Although glycyrrhetinic acid has an excellent anti-inflammatory effect, it has a problem that it is poorly soluble in water and can be used only under limited conditions. For example, a method of dissolving glycyrrhetinic acid in ethanol and blending it in an external preparation for skin or the like, or a method of dissolving glycyrrhetinic acid in an oil agent and then emulsifying it has been performed, but in each case, the composition contains a large amount of water. Since glycyrrhetinic acid was precipitated, it was difficult to obtain a skin external preparation containing a large amount of water such as a lotion or an emulsion.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a water-containing composition in which glycyrrhetinic acid is stably dispersed, and a composition useful for obtaining such a water-containing composition. ..

As a result of research to solve the above problems, the present inventor uses a D (Detergent: surfactant) phase emulsification method and uses a predetermined oil agent, surfactant and polyhydric alcohol to form an O / D type. By preparing an emulsified composition and adding an aqueous medium to the emulsified composition, it has been found that an oil-in-water emulsified composition in which glycyrrhetinic acid is stably dispersed can be obtained, and the present invention has been completed. Specifically, the present invention is as follows.

[1] An O / D type emulsified composition containing glycyrrhetinic acid.
An oil agent (a) containing at least one of a higher alcohol and an ester oil;
Containing nonionic surfactant (b); and polyhydric alcohol (c);
The ratio (b) / (a) of the content of the nonionic surfactant (b) to the content of the oil agent (a) is 0.26 to 3.5.
The ratio (c) / (b) of the content of the polyhydric alcohol (c) to the content of the nonionic surfactant (b) is 0.75 to 6.
An O / D type emulsified composition characterized in that the content of water (d) is 0 to 15% by mass.
[2] The higher alcohol or the ester oil contains at least one selected from the group consisting of isostearyl alcohol, 2-octyldodecanol, hexyldecanol, ethyl hexyl palmitate, and propylene glycol caprylate [1]. ] The O / D type emulsified composition.
[3] The O / D type emulsified composition according to [1] or [2], wherein the oil agent (a) contains at least isostearyl alcohol.
[4] The O / D type emulsified composition according to [1] to [3], wherein the oil agent (a) contains a hydrocarbon.
[5] The O / D type emulsified composition according to [1] to [4], wherein the required HLB of the surfactant in the O / D type emulsified composition of the nonionic surfactant (b) is 11 to 16. object.
[6] The O / D type emulsified composition according to [1] to [5], wherein the polyhydric alcohol (c) contains 1,3-butylene glycol and glycerin.
[7] The O / D type emulsified composition according to [1] to [6], wherein the content of the oil agent (a) is 5 to 70% by mass.
[8] The O / D type emulsified composition according to [1] to [7], wherein the content of the nonionic surfactant (b) is 10 to 30% by mass.
[9] The O / D type emulsified composition according to [1] to [8], wherein the content of the polyhydric alcohol (c) is 16 to 70% by mass.
[10] The method for producing an O / D type emulsified composition according to [1] to [9].
The glycyrrhetinic acid is dissolved in the oil agent (a) to prepare an oil component constituting the oil phase.
The nonionic surfactant (b) and the polyhydric alcohol (c) are mixed to prepare a solution constituting the surfactant phase.
A method for producing an O / D type emulsified composition, which comprises adding an oil component constituting the oil phase to a solution constituting the surfactant phase.
[11] An oil-in-water emulsified composition comprising the O / D type emulsified composition according to [1] to [9] and an aqueous medium.
[12] The oil-in-water emulsified composition according to [11], which has a water content of 35 to 99.999% by mass.
[13] The oil-in-water emulsified composition according to [11] or [12], wherein the average particle size of the oil droplets is 10 to 200 nm.
[14] The O / D type emulsified composition according to [1] to [9] was prepared.
A method for producing an oil-in-water emulsified composition, which comprises adding an aqueous medium to the O / D type emulsified composition.
[15] An external preparation for skin, which comprises the O / D type emulsified composition according to [1] to [9] or the oil-in-water emulsified composition according to [10] to [12].

According to the O / D type emulsified composition of the present invention, an oil-in-water emulsified composition in which glycyrrhetinic acid is stably dispersed can be obtained by adding an aqueous medium. Further, the oil-in-water emulsified composition of the present invention is one in which glycyrrhetinic acid is stably dispersed.

Hereinafter, embodiments of the present invention will be described.

[O / D type emulsified composition]
The O / D type emulsified composition according to the embodiment of the present invention is an oil agent (a) containing glycyrrhetinic acid and containing at least one of a higher alcohol and an ester oil; a nonionic surfactant (b). And polyhydric alcohol (c);

(1) Glycyrrhetinic acid Glycyrrhetinic acid is a compound obtained by hydrolyzing glycyrrhizin extracted from licorice or the like. Glycyrrhetinic acid has an excellent anti-inflammatory effect and is widely blended in external preparations for skin and scalp. The glycyrrhetinic acid may be obtained from an extract from a natural product, or may be synthesized by a known synthetic method.

The content of glycyrrhetinic acid in the O / D composition is not particularly limited, but the lower limit can be, for example, 0.001% by mass or more, 0.01% by mass or more, and glycyrrhetinic acid can be used within such a range. By containing it, the action of glycyrrhetinic acid can be effectively exerted in the obtained O / D type emulsification composition and oil-in-water emulsification composition.
On the other hand, the upper limit value can be, for example, 3.5% by mass or less, 3.2% by mass or less, 2.5% by mass or less, and if the content of glycyrrhetinic acid is in such a range, O / D The dispersibility of glycyrrhetinic acid can be further improved in the mold emulsification composition and the oil-in-water emulsion composition.

(2) Oil agent (a)
(2-1) Higher Alcohol and Ester Oil The oil agent (a) used in the present embodiment contains at least one of higher alcohol and ester oil.
Since the higher alcohol and the ester oil dissolve glycyrrhetinic acid well, the glycyrrhetinic acid can be stably dispersed in the obtained emulsified composition (O / D type emulsified composition and oil-in-water emulsified composition).

As used herein, the term "higher alcohol" refers to a monohydric alcohol having 6 or more carbon atoms. In the present embodiment, the number of carbon atoms is preferably 12 to 22, and more preferably 16 to 20 carbon atoms.
Examples of the higher alcohol that can be used in the present embodiment include lauryl alcohol, myristyl alcohol, cetyl alcohol (cetyl alcohol), hexyldecanol, stearyl alcohol, isostearyl alcohol, 2-octyldodecanol, oleyl alcohol, and behenyl alcohol. Of these, branched alcohols are preferable, and isostearyl alcohols, hexyldecanols, and 2-octyldodecanols are preferable.

Examples of the ester oil that can be used in the present embodiment include an ester of a higher fatty acid and a monohydric alcohol, an ester of a higher fatty acid and a polyhydric alcohol, and the like. In addition, in this specification, "higher fatty acid" means a monovalent carboxylic acid having 6 or more carbon atoms.
Examples of higher fatty acids include capric acid, sebacic acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid and the like.
Examples of alcohols that form esters with fatty acids include monohydric alcohols such as methanol, ethanol, propanol, butanol, pentanol, and ethylhexanol; and polyhydric alcohols such as ethylene glycol, butylene glycol, propylene glycol, and glycerin. ..

Among the esters of the above higher fatty acids and monohydric alcohols or polyhydric alcohols, those such as isopropyl myristate, isopropyl palmitate, diisopropyl myristate, ethylhexyl myristate, ethylhexyl palmitate, propylene glycol monocaprate, and propylene glycol dicaprate. Esters or diesters can be preferably exemplified.

The higher alcohol or the ester oil may be used alone or in combination of two or more.
The higher alcohol or the ester oil preferably has fluidity at room temperature (23 ° C.), that is, the melting point or softening point is preferably 23 ° C. or lower.

The higher alcohol or the ester oil has a solubility of glycyrrhetinic acid at room temperature (23 ° C.) of preferably 1% by mass or more, more preferably 2% by mass or more, and 2.5% by mass or more. Is particularly preferable. By using a higher alcohol or ester oil having a solubility of glycyrrhetinic acid in such a range, the dispersibility of glycyrrhetinic acid can be made particularly excellent in the O / D type emulsification composition and the oil-in-water emulsification composition.

From the above viewpoint, it is preferable to use isostearyl alcohol, 2-octyldodecanol, hexyldecanol, ethyl hexyl palmitate, and propylene glycol caprylate as the higher alcohol or the ester oil, and it is preferable to use isostearyl alcohol. Especially preferable.
In particular, isostearyl alcohol is a liquid at room temperature and has a solubility of glycyrrhetinic acid of more than 3% by mass, so that the dispersibility of glycyrrhetinic acid is particularly excellent. Further, since the emulsion stability is particularly excellent in combination with the nonionic surfactant (b) described later, it is particularly preferably used in the present embodiment.
When isostearyl alcohol is used, the ratio of glycyrrhetinic acid to isostearyl alcohol (glycyrrhetinic acid / isostearyl alcohol) in the O / D type emulsified composition may be 0.00001 to 0.05, 0.001. It may be ~ 0.45 and may be 0.01 ~ 0.04. Within such a range, the action of glycyrrhetinic acid can be easily exerted, and the dispersibility of glycyrrhetinic acid becomes even more excellent.
In the present embodiment, only the isostearyl alcohol may be used as the higher alcohol and the ester oil, or may be used in combination with the other higher alcohols or ester oils described above. The ratio of the isostearyl alcohol content to the total content of the higher alcohol and the ester oil is preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. ..

(2-2) Hydrocarbons In the present embodiment, it is preferable that the oil agent (a) further contains a hydrocarbon. By containing a hydrocarbon, coalescence of micelles can be suppressed in the obtained oil-in-water emulsification composition, and emulsion stability can be enhanced.

Examples of the hydrocarbon include squalane, squalene, liquid paraffin, light isoparaffin, light liquid isoparaffin, hydrogenated polybutene, paraffin, petrolatum, microcrystalline wax, ceresin and the like, and one type may be used alone or in combination of two or more types. be able to. Of these, squalane is particularly preferred.

The ratio of the content of the hydrocarbon to the content of the oil agent (a) is preferably 0.1 to 25% by mass, more preferably 1 to 20% by mass, and 5 to 15% by mass. Is particularly preferable. Within such a range, the emulsion stability effect of the hydrocarbon becomes more remarkable.

(2-3) Content of oil agent The content of the oil agent (a) in the O / D type emulsified composition is preferably 5 to 70% by mass, more preferably 10 to 65% by mass, and 20 It is particularly preferably about 60% by mass.
When the content of the oil agent (a) is 5% by mass or more, it is easy to set the content of glycyrrhetinic acid in the obtained O / D type emulsification composition or oil-in-water emulsification composition within a suitable range. Become. On the other hand, when the content of the oil agent (a) is 70% by mass or less, the emulsification stability of the obtained O / D type emulsification composition or oil-in-water emulsification composition becomes more excellent.

(3) Nonionic surfactant (b)
In this embodiment, a nonionic surfactant is used to emulsify the glycyrrhetinic acid and the oil agent (a). The nonionic surfactant is particularly suitable when used as an external preparation for the skin or scalp because it has excellent emulsion stability and less skin irritation in the present embodiment.

Examples of the nonionic surfactant that can be used in the present embodiment include propylene glycol fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, POE (polyoxyethylene) sorbitan fatty acid ester, and POE sorbit fatty acid. Estel, POE glycerin fatty acid ester, POE alkyl ether, POE fatty acid ester, POE hardened castor oil, POE castor oil, POE phytosterol, POE / POP (polyoxyethylene / polyoxypropylene) copolymer, POE / POP alkyl ether, poly Examples thereof include ether-modified silicone lauric acid alkanolamide, alkylamine oxide, and hydrogenated soybean phospholipid.

In selecting the nonionic surfactant (b), it is useful to consider the required HLB of the surfactant in the O / D type emulsified composition. In the present embodiment, the required HLB of the surfactant in the O / D type emulsified composition is preferably 11 to 16, and particularly preferably 12 to 15. When the required HLB of the surfactant in the O / D type emulsified composition is 11 or more, the water content is increased when water is added to the O / D type emulsified composition to prepare the oil-in-water type composition. It is possible to make it more difficult for liquid / liquid separation between the oil phase and the aqueous phase to occur. On the other hand, when the HLB is 16 or less, the average particle size tends to be uniform, and an oil-in-water composition having good emulsion stability can be easily obtained.

Here, the required HLB in the O / D type emulsification composition is a weighted average of the HLBs of each surfactant contained in the O / D type emulsification composition, and the HLB of the surfactant i is Hi _i. , When the content of the surfactant i is X _i , it is expressed by the following formula.

When one type of surfactant is used, the HLB of the surfactant is the required HLB of the surfactant in the O / D type emulsified composition.
From the viewpoint of facilitating the adjustment of the required HLB of the surfactant in the O / D type emulsified composition within the above range, each nonionic surfactant (b) used in the present embodiment also has an HLB of 11 to 16. It is preferable to use, and it is particularly preferable to use 12 to 15.

From this point of view, examples of the nonionic surfactant (b) that can be particularly preferably used in the present embodiment include POE-cured castor oil, pyroglutamic acid isostearic acid POE-cured castor oil, and POE / POP decyltetradecyl ether.
As the POE-hardened castor oil, those to which 30 to 90 mol of POE is added are preferable, and those to which 40 to 80 mol of POE is added are particularly preferable.
Pyroglutamic acid isostearic acid POE-cured castor oil preferably has 20 to 80 mol of POE added, and particularly preferably 30 to 60 mol of POE added.
As the POE / POP decyltetradecyl ether, those to which 20 to 30 mol of POE is added and 10 to 15 mol of POP are added are preferable.

The content of the nonionic surfactant (b) in the O / D type emulsified composition is preferably 10 to 30% by mass, more preferably 12.5 to 27% by mass, and 15 to 25% by mass. Is particularly preferable.
When the content of the nonionic surfactant (b) is 10% by mass or more, the oil agent can be sufficiently emulsified, and an O / D type emulsified composition and an oil-in-water oil type composition having good emulsification stability can be easily obtained. Become. On the other hand, when the content of the nonionic surfactant (b) is 30% by mass or less, solidification is unlikely to occur as the water content increases, efficient emulsification becomes possible, and an oil-in-water type having good emulsification stability. The composition becomes easy to obtain.

(4) Multivalent alcohol (c)
In the present embodiment, the polyhydric alcohol (c) is used to form the D (Detergent: surfactant) phase in the O / D type emulsified composition. By using the polyhydric alcohol (c), the surfactant solution to be the D phase has isotropic properties, and the phase (O phase) of the oil agent is easily dispersed in the D phase, which is a stable O / D type. An emulsified composition can be obtained.

The polyhydric alcohol (c) used in the present embodiment is not particularly limited as long as it has two or more hydroxyl groups in the molecule.
Specific polyhydric alcohols (c) include, for example, ethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol, glycerin, 1,2-butylene glycol, and 1,3-butylene glycol. Lower polyhydric alcohols such as 1,2-pentanediol, 1,2-hexanediol, 1,2,4-butanetriol; polyethers of polyhydric alcohols such as diethylene glycol, dipropylene glycol, diglycerin; glucose, maltose , Sugars such as sucrose and fluctose; sugar alcohols such as xylitol, sorbitol, inositol and martitol; These can be used alone or in combination of two or more.
Among these, 1,3-butylene glycol, 1,3-propanediol, glycerin, and dipropylene glycol are preferably used, and 1,3-butylene glycol and glycerin are particularly preferable.

Furthermore, in this embodiment, it is particularly preferable to use 1,3-butylene glycol and glycerin in combination. Here, 1,3-butylene glycol is excellent in the action of preventing gelation by the nonionic surfactant (b) and orienting the surfactant toward the interface in an orderly manner while maintaining an appropriate hardness. On the other hand, glycerin is excellent in the action of preventing extreme gelation of the D phase when adding water to the O / D type emulsified composition and efficiently emulsifying. Therefore, by using 1,3-butylene glycol and glycerin in combination, the dispersion stability of glycyrrhetinic acid is improved in the oil-in-water emulsified composition obtained by adding water to the O / D type emulsified composition, and the obtained O is obtained. / D-type emulsification composition and oil-in-water emulsification composition have more excellent emulsion stability.
When 1,3-butylene glycol and glycerin are used in combination, the ratio of the glycerin content to the 1,3-butylene glycol content (glycerin / 1,3-butylene glycol) shall be 0.1 to 0.5. Is preferable, and 0.2 to 0.4 is more preferable.

The content of the polyhydric alcohol (c) in the O / D type emulsified composition is preferably 16 to 70% by mass, more preferably 18 to 65% by mass, and more preferably 20 to 60% by mass. Is particularly preferable.
When the content of the polyhydric alcohol (c) is 16% by mass or more, the viscosity due to water addition to the O / D type emulsified composition is reduced, and the O / D type emulsified composition and the obtained oil-in-water emulsified composition are reduced. The product has excellent emulsion stability. On the other hand, when the content of the polyhydric alcohol (c) is 70% by mass or less, the nonionic surfactant is orderedly oriented to the interface to form an O / D type emulsified composition capable of efficiently dispersing the oil agent. This makes it possible to obtain excellent emulsion stability in the O / D type emulsification composition and the obtained oil-in-water emulsification composition.

(5) Water (d)
In the present embodiment, in forming the D (Detergent: surfactant) phase in the O / D type emulsified composition, water may be used in addition to the nonionic surfactant (b) and the polyhydric alcohol (c). Good. The use of water (d) is preferable because the orientation of the nonionic surfactant to the interface is improved and the dispersibility of the oil phase (O phase) to the D phase is further improved.

In the O / D type emulsified composition, water (d) is an optional component, and the content of water (d) may be 0% by mass. However, in order to improve the interfacial orientation of the nonionic surfactant (b), a small amount of water (d) may be added. For example, the content of water (d) in the O / D type emulsified composition may be 0.1% by mass or more, 0.2% by mass or more, and 0.5% by mass or more. Good.
The upper limit of the content of water (d) in the O / D type emulsified composition is preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 8% by mass or less. preferable. When the content of water (d) in the O / D type emulsification composition is not more than the above upper limit value, it becomes possible to efficiently emulsify under the condition that the D phase is not extremely gelled by water addition, and O / D type emulsification composition. The D-type emulsification composition and the obtained oil-in-water emulsification composition have excellent emulsion stability.

(6) Content ratio In the O / D type emulsified composition according to the present embodiment, the dispersion stability of glycyrrhetinic acid, the emulsified stability of the O / D type emulsified composition, and the oil-in-water emulsified composition described later From the viewpoint of emulsion stability, it is preferable to specify the ratio of the contents of each component within a predetermined range.

In the O / D type emulsified composition of the present embodiment, the ratio (b) / (a) of the content of the nonionic surfactant (b) to the content of the oil agent (a) is 0.26 to 3.5. It is preferably, more preferably 0.3 to 2.5, and particularly preferably 0.5 to 1.5.
When (b) / (a) is 0.26 or more, a sufficient amount of the nonionic surfactant (b) for dispersing the oil agent (a) is contained, and the O / D type emulsified composition and the obtained product. In the oil-in-water emulsified composition to be obtained, the emulsion stability is excellent.
On the other hand, when (b) / (a) is 3.5 or less, a sufficient amount of the oil agent (a) is contained within a range in which the O / D type emulsification composition and the oil-in-water emulsification composition can be well dispersed. Therefore, the dispersion stability of glycyrrhetinic acid is particularly excellent.

In the O / D type emulsified composition of the present embodiment, the ratio (c) / (b) of the content of the polyhydric alcohol (c) to the content of the nonionic surfactant (b) is 0.75 to 6. It is preferably 1.0 to 5, more preferably 1.25 to 4, and particularly preferably 1.25 to 4. When (c) / (b) is in such a range, the effect of stabilizing the dispersion of the oil phase (O phase) by the nonionic surfactant (b) can be effectively exhibited.

In the O / D type emulsified composition of the present embodiment, the ratio (d) / (b) of the content of water (d) to the content of the nonionic surfactant (b) is 0.005 or more and less than 1. It may be 0.01 to 0.7, and may be 0.05 to 0.6.

(7) Method for Producing O / D Type Emulsification Composition The O / D type emulsification composition according to the present embodiment can be produced according to a known D-phase emulsification method.
For example, glycyrrhetinic acid is dissolved in an oil agent (a) containing at least one of the higher alcohol and the ester oil. In this case, in order to increase the solubility of glycyrrhetinic acid, heating may be performed if necessary. If necessary, hydrocarbons are added to the obtained solution to prepare the oil components constituting the oil phase (O phase). Further, a nonionic surfactant (b), a polyhydric alcohol (c) and water (d), if necessary, are mixed to prepare a solution constituting the surfactant phase (D phase).
Next, the O / D type emulsified composition of the present embodiment can be obtained by adding the oil component constituting the O phase to the solution constituting the D phase. In this case, for example, by stirring the solution constituting the D phase, adding the oil constituting the O phase little by little and further stirring, the emulsion stability, the dispersion stability of glycyrrhetinic acid, and the water described later will be described. An O / D type emulsified composition having good emulsion stability when an oil type emulsified composition is prepared can be easily obtained. The stirring conditions are not particularly limited, and for example, by stirring under the conditions of 500 to 2500 rpm and further 1000 to 2000 rpm using a homodisper or the like, the O phase is satisfactorily dispersed in the D phase. ..

[Oil-in-water emulsified composition]
The oil-in-water emulsified composition according to the present embodiment contains the O / D type emulsified composition according to the above-described embodiment and an aqueous medium.
The aqueous medium is a liquid using water as a solvent, and may contain other components as appropriate.

As a method for producing the oil-in-water emulsified composition, an aqueous medium may be added to the O / D emulsified composition according to the above embodiment, and if necessary, an operation such as stirring may be performed as appropriate. In the O / D type emulsification composition, the surfactant phase (D phase) was a continuous phase, but by adding an aqueous medium, the continuous phase is replaced with the aqueous phase, and the oil in water having excellent emulsion stability ( An O / W) type emulsified composition can be easily obtained.
The mixing ratio of the O / D type emulsified composition and the aqueous medium is not particularly limited, and for example, the O / D type emulsified composition: aqueous medium = 0.001: 99.999 to 65:35 can be used. ..

In the obtained oil-in-water emulsified composition, the content of water is preferably 35 to 99.999% by mass, more preferably 40 to 90% by mass. The oil-in-water emulsified composition containing water in such a range has preferable properties as an external preparation for skin and the like because glycyrrhetinic acid and the oil phase can be dispersed more stably and the viscosity and the like are sufficiently low. Here, the water content in the oil-in-water emulsification composition is the total of the water derived from the water (d) of the O / D type emulsification composition and the water derived from the aqueous medium.

The content of glycyrrhetinic acid in the oil-in-water emulsification composition is appropriately determined according to the content of the above water, the content of the oil agent (a) derived from the O / D-type emulsification composition in the oil-in-water emulsification composition, and the like. Although it can be set, for example, the lower limit value can be 0.00001 mass% or more, 0.01 mass% or more, and the upper limit value is 3 mass% or less, 2 mass% or less, 1.5 mass% or more. It can be as follows.

The oil-in-water emulsified composition of the present embodiment does not have to contain substantially ethanol. Since glycyrrhetinic acid is soluble in ethanol, conventional skin external preparations containing glycyrrhetinic acid contain a considerable amount of ethanol, but some consumers are sensitive to ethanol. From the viewpoint of appealing to such consumers, it may be preferable to use an oil-in-water emulsified composition that does not substantially contain ethanol.
The fact that the oil-in-water emulsified composition does not substantially contain ethanol means that, more specifically, the content of ethanol in the oil-in-water emulsified composition can be 0.5% by mass or less, 0.1. It can be 0% by mass or less, 0.03% by mass or less, and can be completely free of ethanol.

In the oil-in-water emulsified composition of the present embodiment, the value of the average particle size (volume average particle size) of the oil droplets is preferably 200 nm or less, more preferably 150 nm or less, and more preferably 100 nm or less. Is particularly preferable. It can be said that the oil-in-water emulsified composition having an average particle size of oil droplets in such a range is excellent in emulsification stability by suppressing creaming of oil droplets. The oil droplets having the average particle size can be easily obtained with the oil-in-water emulsified composition according to the present embodiment. The lower limit of the average particle size is not particularly limited, but may be, for example, 10 nm or more. The average particle size of the oil droplets can be measured using a dynamic light scattering type particle size distribution measuring device or the like.

[External skin preparation]
Since the O / D type emulsification composition or the oil-in-water emulsification composition of the above-described embodiment contains glycyrrhetinic acid, has excellent emulsion stability, and can increase the water content, it is contained in an external preparation for skin. It is suitable for.
The type of external preparation for skin is not particularly limited as long as it is used transdermally. For example, skin cosmetics such as creams, emulsions, lotions, lotions, gels; hair tonics, hair creams, etc. , Hair liquid, shampoo, pomade, rinse and other scalp cosmetics; etc.

The external preparation for skin of the present embodiment is an auxiliary agent or other components used in the production of a normal external preparation for skin as long as it does not interfere with the physiological activity of glycyrrhetinic acid such as anti-inflammatory action, for example, astringent, bactericidal / antibacterial. Agents, whitening agents, ultraviolet absorbers, moisturizers, cell activators, anti-inflammatory / antiallergic agents, antioxidant / active oxygen removers, pH adjusters, fragrances and the like can be used. These components can be used as an oil phase (O phase) or a surfactant phase (D phase) in an O / D type emulsified composition, and / or an aqueous medium in an oil-in-water emulsified composition, depending on their solubility and the like. By containing it, it can be contained in an oil-in-water emulsified composition or an external preparation for skin.

According to the O / D type emulsified composition according to the above-described embodiment, an oil-in-water emulsified composition in which glycyrrhetinic acid is stably dispersed can be easily obtained by adding an aqueous medium. Further, the oil-in-water emulsified composition according to the above embodiment has glycyrrhetinic acid stably dispersed, and is also excellent in emulsification stability, and is suitable as an external preparation for skin.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

Hereinafter, the present invention will be described in more detail by showing production examples, test examples, etc., but the present invention is not limited to the following test examples, etc.

[Preparation of O / D type emulsified composition]
0.2975 parts by mass of glycyrrhetinic acid was added to 8.2 parts by mass of isostearyl alcohol, and the mixture was heated to 100 ° C. to completely dissolve it. 0.0142 parts by mass of squalane was added to and mixed with the obtained solution to prepare an oil component constituting an oil phase (O phase).
4.0 parts by mass of polyoxyethylene (40) hardened castor oil, 4.8 parts by mass of 1,3-butylene glycol, 1.2 parts by mass of glycerin, and 0.5 parts by mass of purified water are stirred and mixed to obtain surface activity. A uniform solution constituting the agent phase (D phase) was obtained. To the obtained solution, 8.475 parts by mass of oil constituting the oil phase (O phase) was gradually added while stirring at 500 rpm using a homodisper (2.5 type, manufactured by Primix Corporation). After the addition, the mixture was further stirred at 500 rpm for 1 minute to obtain an O / D type emulsified composition of Sample 1.
The composition of each component in the O / D type emulsified composition is shown in the upper part of Table 1.

The stability of the obtained O / D type emulsified composition was evaluated according to the following criteria. The results are shown in Table 1.
⊚: It was a clear liquid with very slight viscosity.
◯: It was a very slightly viscous, slightly cloudy liquid.
Δ: It was a very slightly viscous, cloudy liquid.
X: A very slightly viscous, cloudy liquid that was phase-separated immediately after preparation.

[Preparation of oil-in-water emulsified composition]
Purified water 80. While stirring 19.0117 parts by mass of the O / D type emulsified composition of Sample 1 obtained by the above method at 1000 rpm using Homo Disper (2.5 type, manufactured by Primix Corporation). 9883 parts by mass was added, and the mixture was further stirred at 1000 rpm for 1 minute to obtain an oil-in-water emulsified composition.
The composition of each component in the oil-in-water emulsified composition is shown in the lower part of Table 1.

The obtained oil-in-water emulsified composition was stored at 50 ° C. for 30 days, and then the stability was evaluated according to the following criteria. The results are shown in Table 1.
⊚: It was a clear pale blue liquid.
◯: It was a pale blue liquid.
Δ: There was a liquid that was white and a very slight precipitation of glycyrrhetinic acid was confirmed.
X: The liquid was white, phase-separated, and the precipitation of glycyrrhetinic acid was confirmed.
When the particle size of the oil-in-water emulsified composition becomes smaller, light having a short wavelength is more likely to be scattered, and the liquid color becomes blue. That is, the fact that the liquid is pale blue indicates that the particle size of the oil-in-water emulsified composition tends to be small.

Further, the obtained oil-in-water emulsified composition was diluted by adding 200 times the amount of purified water immediately after preparation and after storage at 50 ° C. for 30 days, respectively, and the particle size distribution of oil droplets in the diluted solution was determined. The measurement was performed using a dynamic light scattering type particle size distribution measuring device (Nanotrac WaveII-EX150, manufactured by Microtrac Bell Co., Ltd.), and the median size (D50) was taken as the average particle size. The results are shown in Table 1.

[Samples 2-40]
An O / D type emulsification composition and an oil-in-water emulsification composition were prepared in the same manner as in Sample 1, except that the composition of each component was changed as shown in Table 1. The composition of each component in each O / D type emulsification composition is shown in the upper part of Tables 1 to 3, and the composition of each component in the corresponding oil-in-water emulsification composition is shown in the lower part of Tables 1 to 3, respectively. Shown.

The details of each component used in the preparation of samples 1 to 40 are as follows.
・ Glycyrrhetinic acid (manufactured by Maruzen Pharmaceuticals Co., Ltd.)
(Oil)
・ Isostearyl alcohol (manufactured by Higher Alcohol Industry Co., Ltd.)
・ Octyldodecanol (trade name: Lysonol 20SP, manufactured by Higher Alcohol Industry Co., Ltd.)
・ Ethylhexyl palmitate (trade name: NIKKOL IOP, manufactured by Nikko Chemicals Co., Ltd.)
-Caprylic acid PG: Propylene glycol monocaprylate (trade name: NIKKOL SEFSOL-218, manufactured by Nikko Chemicals Co., Ltd.)
・ Squalene (Product name: Olive Squalene, manufactured by Higher Alcohol Industry Co., Ltd.)
(Nonion surfactant)
・ POE (60) hardened castor oil (trade name: NIKKOL HCO-60, manufactured by Nikko Chemicals Co., Ltd.)
-Pyroglutamic acid isostearic acid POE (40) hardened castor oil (trade name: PYROTER CPI-40, manufactured by Nippon Emulsion Co., Ltd.)
・ POE (20) ・ POP (13) Decyl Tetradecyl Ether (Product Name: Unilube 50MT-2200B, manufactured by NOF CORPORATION)
(Multivalent alcohol)
・ 1,3-butylene glycol (manufactured by Daicel Chemical Industries, Ltd.)
・ Glycerin (manufactured by Sakamoto Pharmaceutical Co., Ltd.)
・ Dipropylene glycol (manufactured by ADEKA)

Regarding the obtained O / D type emulsified composition and oil-in-water emulsified composition, the stability of each and the average particle size of oil droplets in the oil-in-water emulsified composition were measured in the same manner as in Sample 1. The results are shown in Tables 1 to 3.

As shown in Tables 1 to 3, by preparing an oil-in-water emulsification composition from an O / D type emulsification composition satisfying the requirements of the present invention, glycyrrhetinic acid is stably dispersed and also has an emulsion stability. An excellent oil-in-water emulsified composition could be obtained.
On the other hand, in the oil-in-water emulsified composition (Samples 29 to 40) prepared from the O / D type emulsified composition which does not satisfy the requirements of the present invention, precipitation of glycyrrhetinic acid and phase separation were confirmed.

Regarding the particle size distribution of the oil droplets, in Samples 29 to 35 and 40, the oil-in-water emulsified composition was semi-solid (viscosity 4000 mPa · s or more) or solid (viscosity 10,000 mPa · s or more), and was 200 times larger. The average particle size could not be measured because it was not diluted by adding an amount of purified water.
For Samples 36, 37, 38 and 39, the particle size distribution of the oil droplets did not follow the lognormal distribution, and the peak was broad or a peak different from the average particle size peak was confirmed. Further, after the sample 36 was stored at 50 ° C. for 30 days, the phase was completely separated and the particle size could not be measured.

Claims (15)

An O / D type emulsified composition containing glycyrrhetinic acid.
Oil agent (a) containing at least one of a higher alcohol and an ester oil;
Containing nonionic surfactant (b); and polyhydric alcohol (c);
The ratio (b) / (a) of the content of the nonionic surfactant (b) to the content of the oil agent (a) is 0.26 to 3.5.
The ratio (c) / (b) of the content of the polyhydric alcohol (c) to the content of the nonionic surfactant (b) is 0.75 to 6.
An O / D type emulsified composition characterized in that the content of water (d) is 0 to 15% by mass. The higher alcohol or ester oil comprises at least one selected from the group consisting of isostearyl alcohol, 2-octyldodecanol, hexyldecanol, ethyl hexyl palmitate, and propylene glycol caprylate, according to claim 1. O / D type emulsified composition. The O / D type emulsified composition according to claim 1 or 2, wherein the oil agent (a) contains at least isostearyl alcohol. The O / D type emulsified composition according to any one of claims 1 to 3, wherein the oil agent (a) contains a hydrocarbon. The O / D type emulsified composition according to any one of claims 1 to 4, wherein the required HLB of the surfactant in the O / D type emulsified composition of the nonionic surfactant (b) is 11 to 16. object. The O / D type emulsified composition according to any one of claims 1 to 5, wherein the polyhydric alcohol (c) contains 1,3-butylene glycol and glycerin. The O / D type emulsified composition according to any one of claims 1 to 6, wherein the content of the oil agent (a) is 5 to 70% by mass. The O / D type emulsified composition according to any one of claims 1 to 7, wherein the content of the nonionic surfactant (b) is 10 to 30% by mass. The O / D type emulsified composition according to any one of claims 1 to 8, wherein the content of the polyhydric alcohol (c) is 16 to 70% by mass. The method for producing an O / D type emulsified composition according to any one of claims 1 to 9.
The glycyrrhetinic acid is dissolved in the oil agent (a) to prepare an oil component constituting the oil phase.
The nonionic surfactant (b) and the polyhydric alcohol (c) are mixed to prepare a solution constituting the surfactant phase.
A method for producing an O / D type emulsified composition, which comprises adding an oil component constituting the oil phase to a solution constituting the surfactant phase. An oil-in-water emulsified composition comprising the O / D type emulsified composition according to any one of claims 1 to 9 and an aqueous medium. The oil-in-water emulsified composition according to claim 11, wherein the water content is 35 to 99.999% by mass. The oil-in-water emulsified composition according to claim 11 or 12, wherein the average particle size of the oil droplets is 10 to 200 nm. The O / D type emulsified composition according to any one of claims 1 to 9 is prepared.
A method for producing an oil-in-water emulsified composition, which comprises adding an aqueous medium to the O / D type emulsified composition. External use on the skin, which comprises the O / D type emulsified composition according to any one of claims 1 to 9 or the oil-in-water emulsified composition according to any one of claims 10 to 12. Agent.