JP5989137B2 - Oil-in-water emulsion composition and use thereof - Google Patents

Description

  The present invention relates to an oil-in-water emulsion composition and use thereof.

A C ₃₀ compound biosynthesized using squalene as a starting material is called a triterpene. Triterpene compounds are roughly classified into four types, dammarane-based, hopane-based, onoselan-based, lanostane-based, and cycloartane-based, depending on the ring bonding mode.

Of these, the Danmaran group is a group containing the most types of compounds, such as a tetracyclic group such as Danmaran and Euphane, and a pentacyclic group such as Lupine and Oleanane. In addition, many compounds classified as danmarans are known to have pharmacological action or physiological activity.
Many danmaran compounds are known as main components of plant extracts that exhibit functions such as anti-inflammation, moisturizing, whitening, anti-wrinkle and antibacterial when used in cosmetics. Among them, triterpene compounds that are pentacyclic and have a carboxylic acid as a substituent are known to have particularly useful functions as cosmetics (Shingo Tanaka, triterpene and triterpene saponins, revised natural product chemistry) 6th edition, Nanedo (1985), p130-p140).

Although these triterpene compounds are excellent in functionality, they are generally poorly soluble in water and have low solubility in oil, which has been a major limitation when blended into cosmetics and the like. In particular, when blended with transparent cosmetics such as lotions and essences, the transparency is impaired, so the blending amount is limited to a very small amount. Therefore, it has been strongly desired to maintain transparency and achieve a sufficient amount of triterpene.
Further, when this type of triterpene is made into a nano-dispersion for transparency, there is a tendency that particle growth with time tends to be large during storage, and turbidity rises during storage and transparency is significantly impaired. Become. Further, when particle growth occurs, particle aggregation and sedimentation occur, and in an extreme case, there is a problem that the active ingredient is phase-separated, and it has been desired to fundamentally solve these problems.

  As a method for solving these problems, for example, a method of forming an oil-in-water emulsion having oil droplets of 200 nm or less and forming a lamellar liquid crystal film and stabilizing it has been proposed (Japanese Patent Laid-Open No. Hei 8). -127526).

  N-acylamino acid monoesters are conventionally known as good solvents for organic ultraviolet absorbers. For example, JP-A-11-246841 discloses an oily, W / O (water-in-oil) cream form, O / W (oil-in-water type) cream form in which an organic ultraviolet absorber is dissolved in an N-acylamino acid monoester. Lotion is shown.

  JP-T-2008-540670 discloses that an N-acylamino acid compound and glycyrrhetinic acid are used in combination as an active substance for personal care in a personal care composition.

However, in the method described in JP-A-8-127526, the emulsion particles cannot be made to have a particle size of 100 nm or less, and have not been sufficiently transparent.
Japanese Patent Application Laid-Open No. 11-246841 does not disclose a specific example of an emulsion composition in which a triterpene and an N-acylamino acid monoester are combined.
JP 2008-540670 A discloses an example in which an N-acylamino acid compound and glycyrrhetinic acid are combined as an active substance for personal care, but only prescriptions are disclosed in the examples. Specifically, it is not disclosed in what form it is blended. Japanese Patent Application Publication No. 2008-540670 does not disclose further combining a specific component called reticin. Therefore, even if an oil-in-water emulsion composition is prepared according to the formulation described in JP-T-2008-540670, it is considered that the transparency and storage stability of the emulsion composition cannot be maintained.

  Under such circumstances, development of an oil-in-water emulsion composition that can maintain the transparency and storage stability of the emulsion composition is awaited.

  An object of the present invention is to provide an oil-in-water emulsion composition containing a pentacyclic triterpene that can maintain storage stability and transparency. Another object of the present invention is to provide a composition for external skin and a scalp cosmetic capable of maintaining storage stability and transparency.

Means for solving the above-mentioned problems are as follows.
<1> a pentacyclic triterpene, (b) an N-acylamino acid monoester, and (c) an oil phase containing lecithin, and an aqueous phase containing a polyglycerin fatty acid ester of HLB 10-16 , and (b) N -An acylamino acid monoester is a compound comprising a neutral amino acid residue, an alkylacyl group bonded to the N-position of the neutral amino acid residue, and an alkylester moiety. A saturated or unsaturated alkyl acyl group having 6 to 22 linear or branched chains, wherein the alkyl ester moiety is linear or branched having 1 to 40 carbon atoms, or cyclic having 3 to 30 carbon atoms An oil- in- water emulsion composition which is an ester moiety containing an alkyl group .
<2> The water according to <1>, wherein the neutral amino acid is a neutral amino acid selected from the group consisting of glycine, alanine, β-alanine, aminobutyric acid, aminopropionic acid, sarcosine, and N-methyl-β-alanine. Oil-type emulsion composition.
< 3 > (a) The oil-in-water emulsion composition according to <1> or <2> , wherein the pentacyclic triterpene is a pentacyclic triterpene having a carboxyl group.
< 4 > (a) The oil-in-water emulsion composition according to any one of <1> to <3> , wherein the pentacyclic triterpene is glycyrrhetinic acid.
< 5 > (b) N-acyl amino acid monoester is an N-acyl amino acid monoalkyl ester, and an amino acid selected from the group consisting of sarcosine, alanine, glycine and N-methyl-β-alanine is converted to N-caproyl. N-lauroylated, N-myristylated, N-palmitoylated, N-stearoylated, N-behenoylated, or N-cocoylated partial structure and branched or straight chain corresponding to the alkyl part of the ester The oil-in-water emulsion composition according to any one of <1> to < 4 >, which has an alkyl partial structure having an alkyl chain length of 2 to 8 carbon atoms.
< 6 > (b) The oil-in-water emulsion composition according to any one of <1> to < 5 >, wherein the N-acylamino acid monoester is N-lauroyl sarcosine isopropyl.
< 7 > (c) The oil-in-water emulsion composition according to any one of <1> to < 6 >, wherein the lecithin is soybean lecithin.
< 8 > (c) The content of lecithin is 2% by mass to 50% by mass with respect to the total mass of (a) pentacyclic triterpene and (b) N-acylamino acid monoester. 7. An oil-in-water emulsion composition according to any one of 7 > .
< 9> The polyglycerol fatty acid ester of HLB 10 to 16 is at least one compound selected from the group consisting of polyglycerol monooleate, polyglycerol monostearate and polyglycerol monoisostearate <1> <8> The oil-in-water emulsion composition according to any one of the above.
<10> The oil-in-water emulsion composition according to any one of <1> to <9>, including emulsion particles having an average particle diameter of 20 nm to 150 nm.
<11> An external composition for skin containing the oil-in-water emulsion composition according to any one of <1> to <10>.
<12> The external composition for skin according to <11>, wherein the total amount of the oil phase component is 5% by mass or less based on the total mass of the external composition for skin.
<13> The external composition for skin according to <11> or <12>, wherein the content of ethanol is 10% by mass or less based on the total mass of the external composition for skin.
<14> A scalp cosmetic containing the external composition for skin according to any one of <11> to <13>.

  According to the present invention, it is possible to provide an oil-in-water emulsion composition containing a pentacyclic triterpene capable of maintaining storage stability and transparency. Further, according to the present invention, it is possible to provide a composition for external skin and a scalp cosmetic capable of maintaining storage stability and transparency.

<Oil-in-water emulsion composition>
The oil-in-water emulsion composition of the present invention (hereinafter sometimes referred to as “the emulsion composition of the present invention”) comprises (a) a pentacyclic triterpene, (b) an N-acylamino acid monoester, and (c ) An oil-in-water emulsion composition containing an oil phase containing lecithin and an aqueous phase.

  The emulsion composition of the present invention can improve the solubility of the pentacyclic triterpene in the oil phase and exhibit excellent storage stability and transparency by having the above-described configuration.

N-acylamino acid monoester is a highly hydrophilic component. Therefore, when the oil phase component in the emulsion composition contains an N-acyl amino acid monoester, the interfacial tension at the interface between the aqueous phase and the oil phase is lower than when no N-acyl amino acid monoester is contained. Tend to be. As a result, it is presumed that the effect of stabilizing the emulsion particles due to the adsorption to the interface of the emulsifier is reduced, and it is presumed that it is difficult to maintain the storage stability and transparency of the emulsion composition over a long period of time.
On the other hand, in the emulsion composition of the present invention, since the oil phase contains an N-acylamino acid monoester and lecithin, the solubility of the pentacyclic triterpene in the oil phase can be improved, and the length of the emulsion composition can be increased. Storage stability and transparency over a period can be maintained.

  The emulsion composition of the present invention is an oil-in-water emulsion composition, and includes an aqueous phase composition composed of an aqueous phase component and an oil phase composition composed of an oil phase component.

  As will be described later, the emulsion composition of the present invention is preferably obtained by emulsifying and mixing an aqueous phase composition composed of an aqueous phase component and an oil phase composition composed of an oil phase component.

In the present invention, the numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the present invention, the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. To do.
In the present invention, “aqueous phase” is used as a term for “oil phase” regardless of the type of solvent.
In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended purpose of this process is achieved even when it cannot be clearly distinguished from other processes. .
In the present specification, the “polyglycerin fatty acid ester” means an ester containing a plurality of glycerin units and at least one fatty acid unit.
In the present invention, “storage stability” means that after the emulsion composition is prepared, aggregation and coalescence of the emulsion particles over time can be suppressed, and the stability of the emulsified state can be maintained without being impaired. .
Hereinafter, each component in the present invention will be described in detail.

((A) pentacyclic triterpene)
The emulsion particles (oil phase) contained in the oil-in-water emulsion composition of the present invention contain a pentacyclic triterpene.

Since the pentacyclic triterpene is a poorly soluble compound that is hardly soluble in water and oil, it is difficult to uniformly disperse in water and oil, and since crystallization in water is remarkable, However, it was extremely difficult to keep the dispersion state stable. For this reason, conventionally, it has been difficult to obtain a composition containing a pentacyclic triterpene at a concentration sufficient to exhibit the intended function.
On the other hand, since the emulsion composition of the present invention contains N-acylamino acid monoester and lecithin, pentacyclic triterpene can be blended at a high concentration sufficient to exhibit the intended function, and Thus, an oil-in-water emulsion composition having excellent storage stability and transparency can be obtained.

  The pentacyclic triterpene may be a natural product or a synthetic product, but can be mainly obtained from a plant extract. Specifically, a pentacyclic triterpene can be extracted from a plant extract using a solvent such as ethanol.

  Examples of pentacyclic triterpenes in the present invention are pentacyclic having one or more carboxyl groups or derivatives thereof as a substituent in the basic skeleton such as acid type, glycoside type, or fatty acid ester type pentacyclic triterpenes. Triterpenes are mentioned, and any of these triterpenes can be applied in the present invention.

  As for the pentacyclic triterpene in the emulsion composition of the present invention, only one kind may be contained alone in the emulsion particles, or two or more kinds may be used in combination.

Here, the acid-type pentacyclic triterpene is a pentacyclic triterpene having a carboxyl group as a substituent in the basic skeleton.
In addition, glycoside type pentacyclic triterpenes and fatty acid ester type pentacyclic triterpenes are pentacyclic triterpenes having a carboxyl group derivative as a substituent in the basic skeleton. Glycoside pentacyclic triterpenes are those in which the carboxyl group of the basic skeleton is sugar-modified, and fatty acid ester type pentacyclic triterpenes are those in which the carboxyl group of the basic skeleton is modified with fatty acid ester type. It is.

In the glycoside type pentacyclic triterpene, monosaccharide, disaccharide, or oligosaccharide is preferable as the sugar that is a component of the glycoside. Examples include glucose, fructose, galactose, mannose, arabinose (above monosaccharide), maltose, sucrose, lactose (above disaccharide), maltooligosaccharide, fructooligosaccharide, galactooligosaccharide, mannan oligosaccharide, raffinose, stachyose (above oligo) Sugar).
In the fatty acid ester type, examples of the alcohol to be esterified with the carboxyl group of the pentacyclic triterpene include all saturated or unsaturated linear or branched alcohols having 1 to 20 carbon atoms.

  From the viewpoint of pharmacological activity, the pentacyclic triterpene is preferably an acid type pentacyclic triterpene.

  Examples of acid-type pentacyclic triterpenes that can be obtained from plant extracts include asiatic acid, madecascic acid contained in cinnamon extract; ursolic acid, oleanolic acid, betulinic acid contained in rosemary extract; contained in perilla leaf extract Oleanolic acid, ursolic acid, tormentic acid; glycyrrhetinic acid contained in licorice extract; maslinic acid, corosolic acid and the like contained in banaba extract, but are not limited thereto.

  Examples of pentacyclic triterpenes that can be obtained from plant extracts include glycoside pentacyclic triterpenes bound to sugars, in addition to the acid pentacyclic triterpenes described above. The glycoside pentacyclic triterpene is a form that exists in a large amount as a storage form (referred to as a heteroside) in a plant body, and can easily produce an acid type triterpene (sapogenin or aglycone) by hydrolysis or enzymatic degradation. Are known.

Among these pentacyclic triterpenes, glycyrrhetinic acid is preferable from the viewpoint of anti-inflammatory effect, antioxidant effect, anti-aging effect and the like. Glycyrrhetinic acid is one of β-amylin (oleanan) -based pentacyclic terpenoid derivatives obtained by hydrolysis of glycyrrhizic acid obtained from licorice. Glycyrrhetinic acid can be blended in cosmetics and quasi-drugs for anti-aging care and the like in anticipation of anti-inflammatory action, antioxidant action and anti-aging action in the cosmetics field.
Glycyrrhetinic acid is said to have a remarkable effect on acute or chronic dermatitis, and is known to have anti-inflammatory effects, anti-allergic effects, and bacteria (S. aureus, diphtheria, salmonella, etc.) growth inhibitory effects. Yes. Glycyrrhetinic acid is excellent in alleviating skin inflammation, suppressing sebum secretion in acne and the like, and anti-inflammatory effect, and is used in many skin care products and lipsticks. In addition, scalp care products are often used because they have effects such as preventing hair loss and suppressing dandruff and itching.

  The pentacyclic triterpene in the present invention can be used in the form of an extract extracted from a plant extract, for example. In this case, since a plurality of types of triterpenes having different structures are usually mixed in the plant extract, a plurality of types of pentacyclic triterpenes are mixed in the emulsion particles.

In addition, as the pentacyclic triterpene in the present invention, β-glycyrrhetinic acid, asiatic acid, ursolic acid, oleanolic acid, betulinic acid, corosolic acid and the like which can be synthesized according to a known synthesis method may be used.
Moreover, the pentacyclic triterpene in this invention may use a commercial item. Examples of commercially available products include TECA (trade name) manufactured by Bayer Healthcare Co., Ltd., tsuboxa extract, dextran extract, β-glycyrrhetinic acid manufactured by Maruzen Pharmaceutical Co., Ltd., asiatic acid manufactured by Bayer Healthcare, manufactured by Sabinsa Japan Examples include ursolic acid; oleanolic acid manufactured by Tokyo Chemical Industry.

  The content of the pentacyclic triterpene in the emulsion composition of the present invention is preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass to 5% with respect to the total mass of the emulsion composition. More preferably, it is 0.1% by mass to 2% by mass from the viewpoint of high concentration and stability.

  Further, the content of the pentacyclic triterpene in the entire emulsion particle (oil phase) of the present invention is preferably 0.5% by mass or more and 20% by mass or less, and preferably 1% by mass with respect to the total mass of the entire emulsion particle (oil phase). % To 10% by mass is particularly preferable.

((B) N-acyl amino acid monoester)
The emulsion particles (oil phase) contained in the oil-in-water emulsion composition of the present invention contain an N-acyl amino acid monoester.

The pentacyclic triterpene is a poorly soluble compound that is hardly soluble in water and oil, and it has been difficult to obtain a composition containing a pentacyclic triterpene at a concentration sufficient to exhibit the intended function. .
On the other hand, since the oil-in-water emulsion composition of the present invention contains an N-acylamino acid monoester, a pentacyclic triterpene can be blended at a high concentration sufficient to exhibit the intended function. .

  N-acylamino acid monoesters may be synthesized by a chemical reaction between an acyl group, a neutral amino acid, and an alcohol that forms an ester moiety. Examples of the method for synthesizing the N-acylamino acid monoester include the methods described in paragraph numbers [0047] to [0053] of JP-A No. 11-246841.

As the acyl group, for example, an acyl group having a straight chain or branched chain having 6 to 22 carbon atoms and having a hydroxyl group removed from a saturated or unsaturated carboxylic acid, for example, capric acid, lauric acid, myristic acid, Examples include acyl groups that can be derived from palmitic acid, stearic acid, behenic acid, linoleic acid, linolenic acid, oleic acid, isostearic acid, 2-ethylhexanoic acid, coconut oil fatty acid, beef tallow fatty acid, hardened tallow fatty acid and the like.
Preferred acyl groups include caproyl group, lauroyl group, myristyl group, palmitoyl group, stearoyl group, behenoyl group, cocoyl group and the like.

  Examples of neutral amino acids include glycine, alanine, β-alanine, aminobutyric acid, aminopropionic acid, sarcosine, N-methyl-β-alanine, and preferably glycine, alanine, valine, leucine, isoleucine, Serine, threonine, proline, β-alanine, aminobutyric acid, sarcosine, N-methyl-β-alanine, particularly preferably sarcosine, alanine, glycine and N-methyl-β-alanine. These amino acids may be either optically active or racemic.

As an example of alcohol which comprises an ester site | part, a C1-C40 linear or branched chain, a C3-C30 cyclic alcohol, etc. are mentioned.
Examples of the linear or branched alcohol having 1 to 40 carbon atoms include lower alcohols having 1 to 5 carbon atoms and higher alcohols having 6 to 20 carbon atoms.
From the viewpoint of the solubility of the pentacyclic triterpene in the oil phase, alcohols having a branched or linear alkyl group or alkenyl group having 1 to 10 carbon atoms in the molecule are preferable, and those having 1 to 10 carbon atoms. Alcohols having a branched or straight chain alkyl group in the molecule are more preferred.
Examples of the cyclic alcohol having 3 to 30 carbon atoms include cyclopropanol, cyclobutanol, cyclopentanol, and cyclohexanol.
In addition to the above, examples of alcohols constituting the ester moiety include sterols such as cholesterol, dihydrocholesterol, and phytosterol.
Examples of alcohols constituting the ester moiety include, for example, methanol, ethanol, propanol, isopropanol, butanol, t-butanol, isobutanol, 3-methyl-1-butanol, 2-methyl-1-butanol, pentanol, Hexanol, cyclohexanol, octanol, 2-ethyl-hexanol, decanol, fusel oil and the like.
Among them, alcohols having a branched or straight chain alkyl group having 2 to 8 carbon atoms in the molecule are preferable, and isopropanol is most preferable.

  Examples of combinations of acyl groups, neutral amino acids, and alcohols that create ester sites used in the synthesis of N-acyl amino acid monoesters include “lauroyl group, sarcosine and isopropanol”, “myristoyl group, β-alanine” And phytosterols "or combinations such as" caproyl group, glycine and isobutanol ".

In addition, the N-acylamino acid monoester in the present invention can be synthesized according to the above-described known synthesis method, or a commercially available product may be used. Examples of commercially available products include N-lauroyl sarcosine isopropyl (trade name: Erdeu SL-205) manufactured by Ajinomoto Co., Inc., N-myristoyl-N-methyl β-alanine phytosteryl decyltetradecyl (trade name: Erdueu APS307), Japan Examples include emulsion myristoylmethylaminopropionate hexyldecyl (trade name AMITER MA-HD).
These N-acylamino acid monoesters can be used singly or in combination as necessary.

As an N-acyl amino acid monoester, an amino acid selected from the group consisting of sarcosine, alanine, glycine and N-methyl-β-alanine is converted to N-caproylation, N-lauroylation, N-myristylation, and N-palmitoylation. N-stearoylated, N-behenoylated, or N-cocoylated partial structure, and a branched or linear partial structure obtained by alkyl esterification and having an alkyl chain length of 2 to 8 carbon atoms. Having an amino acid selected from the group consisting of sarcosine, alanine, glycine and N-methyl-β-alanine (N-caproylated, N-lauroylated, N-myristyl) , N-palmitoylation, N-stearoylation, N-behenoylation, or N-cocoylation And those having a branched or straight chain corresponding to the alkyl portion of the ester and having an alkyl chain length of 2 to 8 carbon atoms) are preferred.
Particularly preferred as N-acylamino acid monoester is N-lauroylsarcosine isopropyl.

  The content of the N-acylamino acid monoester in the oil-in-water emulsion composition of the present invention is 2 to 200 times on a mass basis with respect to the total mass of the pentacyclic triterpene contained in the oil-in-water emulsion composition. Preferably, 5 times to 100 times are more preferable, and 10 times to 50 times are more preferable. When the total mass of the pentacyclic triterpene contained in the oil-in-water emulsion composition is in the range of 2 to 200 times on a mass basis, the stability of the emulsion composition is favorable and preferable.

((C) lecithin)
The oil-in-water emulsion composition of the present invention contains lecithin in the oil phase composition.

N-acylamino acid monoester is a highly hydrophilic component. Therefore, when the N-acylamino acid monoester contains an oil phase component, the interfacial tension between the aqueous phase interface and the oil phase interface tends to be lower than when no N-acylamino acid monoester is contained. . As a result, it is presumed that the effect of stabilizing the emulsion particles due to the adsorption to the interface of the emulsifier is reduced, and it is presumed that it becomes difficult to maintain the storage stability and transparency of the emulsion composition by storage over time.
On the other hand, since the emulsion composition of the present invention contains lecithin, the emulsion composition containing an N-acylamino acid monoester in the oil phase can maintain the storage stability and transparency over a long period of time.

  In the present specification, lecithin is not limited to phosphatidylcholine (PC), but means a lipid mixture mainly composed of various phospholipids. Examples of lipids include phosphatidic acid, phosphatidylglycerin, phosphatidylinositol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylcholine, phosphatidylserine, bisphosphatidic acid And glycerolecithin such as diphosphatidylglycerin (cardiolipin); sphingolecithin such as sphingomyelin and the like.

  Lecithin is often used as an emulsifier for foods and cosmetics because of its safety and emulsifying ability to form an emulsion by dispersing oil in water. In pharmaceuticals, osmotic action that permeates and absorbs substances from the skin and mucous membranes is used, and it is used as a material for pharmaceutical liposomes, fat emulsions for intravenous injections, therapeutic agents for wrinkles and skin diseases. Soy lecithin is often used for food and cosmetics mainly from the viewpoint of cost.

Lecithin is a kind of glycerophospholipid, which is present in all cells of natural animals and plants, and is a major component of biological membranes.
Examples of lecithin derived from natural products that can be used in the present invention include lecithin derived from soybeans, lecithin derived from egg yolk, and lecithin derived from animals and plants.

Soy lecithin is produced by drying and refining oil cake produced as a by-product in the soybean oil refining process. Pasty lecithin having a phospholipid content of 70% or less is inexpensive because it contains about 30% crude soybean oil, and in the food field, this paste-like lecithin having a phospholipid content of 70% or less is used.
In recent years, techniques such as high purification, fractionation, and modification have been added due to the physiological activity of phospholipids themselves and the need for more advanced emulsifiers, and various lecithin groups having different performance and functions have been created.

Highly purified lecithin is deoiled from the above-mentioned pasty lecithin using a solvent such as acetone and powdered, and generally has a lecithin content of 90% or more.
Examples of this highly purified lecithin include commercially available products such as Phospholipon 20 (Lipoid), Recion P (Riken Vitamin), SLP White (Tsubame Oil Co., Ltd.), Emmalmatic 300 (Lucas Meier Cosmetics).

  In addition to ordinary purified lecithin, fractionated lecithin mainly with increased phosphatidylcholine (PC) content, enzymatically degraded (lyso) lecithin that has been single-stranded by enzymatic degradation, hydrogenated lecithin that has undergone hydrogenation treatment, etc. These modified lecithins can also be used in the present invention.

Fractionated lecithin is obtained by increasing the content of a specific phospholipid from the above highly purified lecithin by utilizing the difference in solubility in various solvents or by operations such as distillation, and generally has a PC content increased. ing.
Examples of fractionated lecithin with an increased PC content include Phospholipon 50 (PC 45%), Phosphopon 85G (PC 80%), Phosphopon 90G (PC 94%) (above, Lipoid), Emmeletic 900 ( PC50%), Emmeletic 930 (PC95%) (above, Lucas Meyer Cosmetics), SLP-PC70, SLP-PC90 (above, Sakai Oil), etc. are commercially available.

The modified lecithin can be roughly classified into hydrogenated lecithin and enzymatically decomposed lecithin.
Among these, hydrogenated lecithin is obtained by converting a fatty acid polyenoic acid in a lecithin structure into a saturated fatty acid by performing a hydrogenation treatment in order to oxidize or improve light stability. This lecithin can be preferably used for cosmetics and pharmaceuticals.
Examples of hydrogenated lecithin include Emalmetic 320 (Lucas Meyer Cosmetics), SLP White H (Tsubaki Oil) and the like. Examples of products that have been subjected to hydrogenation treatment after increasing the PC content include commercially available products such as Emulmatic 950 (Lucas Meyer Cosmetics), SLP-PC92H (Sakai Oil), Phospholipon 90H (Lipoid). Yes.

  On the other hand, enzyme-decomposed lecithin is obtained by selectively decomposing an ester bond of a fatty acid at the 2-position, which is usually bonded to glycerin, with an enzyme, and is called lysolecithin to distinguish it from normal lecithin. Lysolecithin has improved water solubility and generally improves emulsifying power compared to the original lecithin. This enzymatic decomposition treatment is usually performed on the first pasty lecithin and then highly purified, but the enzymatic decomposition treatment may be performed on the fractionated lecithin. A typical example of lysolecithin is SLP white lyso (Tsubaki Oil).

  Moreover, what decomposes | disassembles the ester bond between phosphoric acid and a base as a different enzyme-treated lecithin is also made. By performing this treatment, the base is removed from the phospholipid, and it becomes a phosphatidic acid form, thereby showing strong anionicity. As an example of this type of enzyme-treated lecithin, PA Nagase, lysophospholipid Nagase H and the like are commercially available.

In the present invention, any of the above-mentioned lecithins may be used, but from the viewpoint of maintaining the storage stability and transparency of the emulsion composition, soybean lecithin is preferable, and among them, highly purified lecithin, fractionation Lecithin is more preferred.
In addition, these lecithins that can be used in the present invention can be used alone or in the form of a mixture of plural kinds.
Among them, the phospholipid content is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more with respect to the total mass of lecithin.
Further, the phospholipid preferably contains phosphatidylcholine (PC) in an amount of 10% by mass to 100% by mass, more preferably 20% by mass to 90% by mass, and more preferably 30% by mass to 80%. What contains mass% is further more preferable.

  Moreover, as a lecithin, you may use a commercial item. Examples of commercially available products include SLP-White (manufactured by Sakai Oil), Emmeletic 900 (manufactured by Lucas Meyer), Phospholipon 50 (manufactured by Lipoid), Recion P (manufactured by Riken Vitamin), and the like.

  The content of lecithin in the oil-in-water emulsion composition of the present invention is 2% by mass to 50% by mass with respect to the total mass of (a) pentacyclic triterpene and (b) N-acylamino acid monoester. It is preferable that it is preferably 4% by mass to 40% by mass, and particularly preferably 6% by mass to 30% by mass.

(Other oil phase components)
The oil-in-water emulsion composition of the present invention may contain various oil phase components in addition to the pentacyclic triterpene, N-acyl amino acid monoester and lecithin.
As an example of an oil phase component, the oil phase component which shows a useful effect, for example when used for cosmetics etc. is mentioned.
Specific examples of oil phase components include oils and fats, hydrocarbons, waxes, esters, fatty acids, higher alcohols, polymers, oil-soluble pigments, oil-soluble proteins in terms of chemical structure. Etc.
In addition, various vegetable oils and animal oils, which are mixtures thereof, are also included in the examples of the oil phase components.

Examples of these oil phase components are more specifically fats and oils such as coconut oil, olive oil, corn oil and jojoba oil; higher fatty acids such as stearic acid, oleic acid, palmitic acid, myristic acid and lauric acid Higher alcohols such as behenyl alcohol, stearyl alcohol, cetanol, isostearyl alcohol, oleyl alcohol, decanol, dodecanol, tetradecanol, hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol; cholesterol, phytosterol, etc. Sterols; esters such as ethylhexyl palmitate, isopropyl myristate, octyldodecyl myristate, di-N-lauroyl-L-glutamate (phytosteryl, 2-octyldodecyl); squalane, water Polydecene, hydrocarbons such as hydrogenated polyisobutene, and the like.
In addition, as oil phase components (functional oil phase components) having characteristic functions, carotenoids such as β-carotene, astaxanthin, zeaxanthin, lycopene and lutein; vitamin Es such as tocopherol and tocotrienol; ubiquinones such as coenzyme Q10 Ω-3 oils and fats such as EPA, DHA, and linolenic acid may also be included.

Furthermore, although it is expensive as an oil phase component having a moisturizing function, active ceramides such as ceramide I, ceramide II, ceramide III, ceramide V and ceramide VI; glycosphingolipids such as glucosylceramide and galactosylceramide; sphingomyelin , Pseudoceramides can also be included.
Moreover, a phenolic antioxidant, a ultraviolet absorber, an emollient, etc. can also be contained as other oil phase components.

  The total mass of the pentacyclic triterpene, N-acylamino acid monoester and lecithin is preferably 30% by mass to 100% by mass, and 50% by mass to 100% by mass with respect to the total mass of the oil phase component in the emulsion composition of the present invention. Is more preferable, and 70% by mass to 100% by mass is particularly preferable.

(Emulsion particles)
The emulsion particles contained in the emulsion composition of the present invention are preferably emulsion particles having an average particle size of 20 nm to 150 nm.

The average particle diameter of emulsion particles means the volume average particle diameter of emulsion particles (oil droplets) present in the emulsion composition.
The average particle size of the emulsion particles in the present invention is preferably 20 nm to 150 nm, more preferably 20 nm to 100 nm, and still more preferably 20 nm to 80 nm, from the viewpoint of storage stability and composition transparency.

The average particle size of the emulsion particles contained in the emulsion composition of the present invention can be determined by a known method such as an electron microscope, a centrifugal sedimentation method, a liquid exclusion chromatography method, a laser scattering diffraction method, or a dynamic light scattering method. However, from the viewpoint of accuracy and simplicity of measurement, it is preferable to measure using a dynamic light scattering method.
Examples of commercially available measuring devices using dynamic light scattering include dense particle size analyzer FPAR-1000 (Otsuka Electronics Co., Ltd.), Nanotrack UPA (Nikkiso Co., Ltd.), Nanosizer (manufactured by Malvern), etc. Although the particle diameter in this invention is mentioned, the value measured at 25 degreeC using Nanotrac UPA is employ | adopted.
Specifically, the emulsion composition is measured as it is without being diluted, and is determined as the median diameter (d = 50).
The average particle size of the emulsion particles can be adjusted by factors such as the stirring conditions (shearing force, temperature, pressure) in the production method and the ratio of the oil phase to the water phase, in addition to the components of the composition. .

(Water phase component)
The emulsion composition of the present invention can appropriately contain a polyglycerin fatty acid ester and other water-soluble substances in the aqueous phase.

(Polyglycerin fatty acid ester)
The oil-in-water emulsion composition of the present invention may be added with a polyglycerin fatty acid ester of HLB 10 to 16 in the aqueous phase from the viewpoint of making the emulsion particles finer and further improving the storage stability of the emulsion composition. preferable.
The polyglycerol fatty acid ester added to the oil-in-water emulsion composition is presumed to function as an emulsifier.

From the viewpoint of emulsifying power, the polyglycerin fatty acid ester is more preferably HLB 11-15.
Here, HLB is a hydrophilic-hydrophobic balance that is usually used in the field of surfactants, and a commonly used calculation formula such as the Kawakami formula can be used. Kawakami's formula is shown below.
HLB = 7 + 11.7 log (M _w / M ₀ )
Here, the molecular weight M _w of the hydrophilic group, M ₀ is the molecular weight of the hydrophobic group.
Moreover, you may use the numerical value of HLB described in the catalog etc.
Further, as can be seen from the above formula, an emulsifier having an arbitrary HLB value can be obtained by utilizing the additivity of HLB.

As the polyglycerol fatty acid ester, polyglycerol monooleate of HLB 10-16, polyglycerol monostearate of HLB 10-16, polyglycerol monoisostearate of HLB 10-16, or the like is preferable.
Preferred specific examples of the polyglycerol fatty acid ester include hexaglycerol monomyristic acid ester, hexaglycerol monolaurate ester, decaglycerol monooleate ester, decaglycerol monostearate ester, decaglycerol monoisostearate ester, decaglycerol monopalmitic acid Examples thereof include esters, decaglycerin monomyristic acid ester, decaglycerin monolauric acid ester, decaglycerin monolinoleic acid ester, decaglycerin diisostearic acid ester and the like. Of these, decaglycerin monooleate, decaglycerin monostearate, decaglycerin monoisostearate, decaglycerin monopalmitate, decaglycerin monomyristate, decaglycerin monooleate, decaglycerin are preferred. Monostearic acid ester and decaglycerin monoisostearic acid ester are particularly preferred.
Moreover, as a polyglycerol fatty acid ester, you may use a commercial item. Examples of commercially available products include polyglyceryl isostearate-10 (HLB = 12) (manufactured by Nikko Chemical), polyglyceryl-10 oleate (HLB = 12) (manufactured by Nikko Chemical), polyglyceryl-10 myristate (HLB = 14), Examples thereof include polyglyceryl stearate-10 (HLB = 12), polyglyceryl myristate-6 (HLB = 11), and the like.
These polyglycerin fatty acid esters can be used singly or in combination.

  The content of the polyglycerol fatty acid ester in the oil-in-water emulsion composition of the present invention is preferably 0.1% by mass to 20% by mass with respect to the total mass of the emulsion composition, and 0.5% by mass to More preferably, it is 15 mass%, and 1 mass%-10 mass% are especially preferable.

(Other water phase components)
As an aqueous phase component of the emulsion composition of the present invention, in addition to polyglycerin fatty acid ester, polyhydric alcohol, nonionic surfactant other than polyglycerin fatty acid ester, ionic surfactant, water-soluble salts, polysaccharides , Proteins, pH adjusters, antioxidants, preservatives, pigments, fragrances, and the like.

The emulsion composition of the present invention can contain a polyhydric alcohol for the purpose of antiseptic properties and viscosity adjustment.
The polyhydric alcohol that can be used in the emulsion composition of the present invention is not particularly limited as long as it is a dihydric or higher alcohol. For example, glycerin, diglycerin, triglycerin, polyglycerin, 3-methyl-1,3-butanediol, 1,3-butylene glycol, isoprene glycol, polyethylene glycol, 1,2-pentanediol, 1,2-hexanediol , Propylene glycol, dipropylene glycol, polypropylene glycol, ethylene glycol, diethylene glycol, pentaerythritol, neopentyl glycol, maltitol, reduced starch syrup, sucrose, lactitol, palatinit, erythritol, sorbitol, mannitol, xylitol, xylose, glucose, lactose, mannose , Maltose, galactose, fructose, inositol, pentaerythritol, maltotriose, sorbitan, treha Over scan, amylolytic sugar, starch decomposed sugar reduced alcohol.
These dihydric or higher polyhydric alcohols can be used alone or in the form of a mixture of plural kinds. Moreover, these polyhydric alcohols can be mixed and used in arbitrary ratios with respect to the total mass of the aqueous phase composition.

Examples of nonionic surfactants other than polyglycerin fatty acid ester include glycerin fatty acid ester, organic acid monoglyceride, polyglycerin fatty acid ether, propylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, Polyoxyethylene sterol, polyoxyethylene hydrogenated castor oil, polyglycerin condensed ricinoleic acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester (polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monooleate) ) And the like. Among these, polyoxyethylene hydrogenated castor oil and polyoxyethylene sterol are preferable.
Preferable examples of the polyoxyethylene hydrogenated castor oil include PEG-60 hydrogenated castor oil and PEG-80 hydrogenated castor oil. Examples of polyoxyethylene sterols include PEG-20 soy sterol and PEG-30 soy sterol.
These nonionic surfactants can be used singly or in combination.

  The total amount of the nonionic surfactant including the polyglycerin fatty acid ester is preferably 0.1% by mass to 20% by mass, and 0.5% by mass to 15% by mass with respect to the total mass of the emulsion composition. It is more preferable that 1% by mass to 10% by mass is particularly preferable.

Examples of ionic surfactants include alkyl sulfonates, alkyl sulfates, monoalkyl phosphates, and fatty acid salts. As the salts, sodium chloride, sodium citrate, sodium ascorbate and the like are used. Examples of the polysaccharide include maltodextrin, oligosaccharide, inulin, gum arabic, chitosan, cyclodextrin, cluster dextrin and the like. Examples of proteins include various amino acids, oligopeptides, gelatin, water-soluble collagen, casein and the like.
These ionic surfactants can be used singly or in combination. Moreover, these ionic surfactants can be mixed and used in arbitrary ratios with respect to the total mass of the aqueous phase composition.

As the pH adjuster, a base solution such as sodium hydroxide, an acid such as hydrochloric acid, a buffer solution such as a phosphate buffer or a citrate buffer can be used.
Examples of the antioxidant include ascorbic acid, ascorbic acid derivatives, citric acid monoglyceride and the like.

  The emulsion composition of the present invention can be produced according to a known method. Examples of preferred production methods for the emulsion composition of the present invention include the production methods described below.

<Method for producing oil-in-water emulsion composition>
The oil-in-water emulsion composition of the present invention is obtained by mixing an oil phase composition containing (a) a pentacyclic triterpene, (b) an N-acylamino acid monoester, and (c) lecithin with an aqueous phase composition. It can be produced by emulsification. The method for producing the oil-in-water emulsion composition of the present invention is shown below. However, the method for producing the emulsion composition of the present invention is not limited to the following method.

First, it is preferable to prepare a uniform oil phase composition by mixing the above-described pentacyclic triterpene, N-acylamino acid monoester, and lecithin and heating to 60 ° C. to 90 ° C. The oil phase composition may contain other oil phase components as required.
Next, the prepared oil phase composition can be added and mixed with stirring into an aqueous phase composition containing a predetermined aqueous phase component heated to 40 ° C to 90 ° C.

The mixing ratio (mass) of the oil phase composition and the aqueous phase composition at this time is not particularly limited, but is 0.1 / 99 as an oil phase composition / water phase composition ratio (mass%). .9 to 50/50 is preferable, 0.5 / 99.5 to 30/70 is more preferable, and 1/99 to 20/80 is still more preferable.
By setting the ratio of the oil phase composition / water phase composition to 0.1 / 99.9 or more, the active ingredient does not decrease, so that the practical problems of the emulsion composition tend not to occur, which is preferable. Further, by setting the ratio of the oil phase composition / water phase composition to 50/50 or less, the emulsifier concentration does not become thin, and the stability of the emulsion composition tends not to deteriorate, which is preferable.

When the oil phase composition and the aqueous phase composition are mixed and emulsified, the oil phase composition and the aqueous phase composition are mixed to obtain a coarse emulsion, and then finely divided using a fine emulsification means. Is preferable.
As a means for mixing the oil phase composition and the aqueous phase composition to obtain a crude emulsion, any commercially available mixing means may be used. For example, a uniform coarse emulsion can be prepared by mixing and stirring an aqueous medium with a magnetic stirrer, household mixer, paddle mixer, impeller mixer or the like.
Further, it is more preferable to mix the oil phase composition and the aqueous phase composition using a stirring means having a strong shearing force, that is, a homomixer, a disper mixer, an ultramixer or the like.
Furthermore, in order to enhance the effect of coarse emulsification, it is also preferable to use ultrasonic waves in addition to these stirring means.
As the ultrasonic wave imparting means, it is preferable to use an ultrasonic homogenizer. Examples of ultrasonic homogenizers include ultrasonic homogenizer US-600, US-1200T, US-1200T, US-1200T, and US-1200T (above, manufactured by Nippon Seiki Seisakusho Co., Ltd.), ultrasonic processor UIP2000, UIP-4000. , UIP-8000, UIP-16000 (above, manufactured by Heelscher) and the like.
These high-power ultrasonic irradiation devices can be used at a frequency of 25 kHz or less, preferably 15 to 20 kHz.
As another mixing means, a static mixer, a microchannel, a micromixer, or the like that does not have an external stirring unit and requires only low energy can be used.
The rough emulsification treatment can be carried out at an arbitrary temperature of 20 ° C. or higher and 90 ° C. or lower, preferably 40 ° C. or higher and 80 ° C. or lower.

Next, it is preferable to refine the resulting coarse emulsion using a fine emulsification means.
As a means for miniaturization, it is preferable to use a high-pressure homogenizer. Since the high-pressure homogenizer can give a larger shearing force than the stirring method, it can be miniaturized, and various apparatuses are commercially available.
High-pressure homogenizers can be broadly classified into a chamber-type high-pressure homogenizer having a fixed throttle portion and a homogeneous valve-type high-pressure homogenizer that controls the opening of the throttle. Examples of the former chamber type high-pressure homogenizer include a microfluidizer (manufactured by Microfluidics), a nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.), a starburst (manufactured by Sugino Machine Co., Ltd.), and the like. As the latter homogeneous valve type high pressure homogenizer, Gorin type homogenizer (manufactured by APV), Lanier type homogenizer (manufactured by Lanier), high pressure homogenizer (manufactured by Niro Soabi), homogenizer (manufactured by Sanwa Machinery Co., Ltd.), high pressure A homogenizer (made by Izumi Food Machinery Co., Ltd.), an ultrahigh pressure homogenizer (made by Ika Corporation), etc. are mentioned.

The high-pressure homogenizer is equipped with a very narrow chamber part and throttle part in the flow path, and a liquid is forcibly sent using a pump to the narrow flow path, creating a very large pressure difference before and after the throttle part, Using this pressure difference as driving energy, the liquid moves through a narrow pipe line at a speed comparable to the speed of sound, so a large shearing force is generated between the flow path walls and this becomes a dispersion force.
The applied pressure and the generated shear force are in a proportional relationship, and the higher the pressure applied, the higher the shear energy used for dispersion. However, not all shear force is used for dispersion, and it is known that the higher the pressure, the lower the energy efficiency and the greater the rate of conversion to heat. is there.

  In the production of the emulsion composition of the present invention, from the viewpoint of dispersibility (miniaturization), the pressure is 100 MPa or more, and more preferably 150 MPa or more. In the commercially available apparatus, the limit on the high pressure side is preferably 300 MPa or less from the viewpoint of temperature rise and pressure resistance.

In the case of refining using a fine emulsification means, the number of times of high-pressure treatment may be one, but in order to improve the uniformity of the whole liquid, it is preferable to carry out two or more high-pressure treatments. More preferably, the high pressure treatment is performed 5 times.
The temperature before the high-pressure dispersion treatment is preferably set to 20 ° C. to 80 ° C., more preferably 40 ° C. to 70 ° C. Immediately after the high-pressure dispersion treatment, it is preferable to quickly cool using a cooling means and lower the temperature to a predetermined temperature. Any commercially available heat exchanger can be used as the cooling device.

<Skin external composition>
The composition for external use of the skin of the present invention is an oil-in-water emulsion composition containing (a) a pentacyclic triterpene, (b) an N-acylamino acid monoester, and (c) an oil phase containing lecithin, and an aqueous phase. Containing.
Thereby, the composition for external use of skin of this invention can maintain storage stability and transparency.

For the details of the oil-in-water emulsion composition, the above-mentioned matters are applied as they are.
In addition to the components described in the section of the oil-in-water emulsion composition, the external composition for skin of the present invention is also referred to as an additive component (hereinafter referred to as “other additive component”) that is generally used in the fields of food, cosmetics and the like. ) May be appropriately contained according to the form.

The other additive component can be contained in the external composition for skin of the present invention as an oil-soluble or water-soluble additive component depending on its characteristics.
Examples of other additive components include polyhydric alcohols such as glycerin and 1,3-butylene glycol; copper carrageenan, locust bean gum, guar gum, hydroxypropyl guar gum, xanthan gum, karaya gum, tamarind seed polysaccharide, gum arabic, acacia Monosaccharides or polysaccharides such as gums, alkaligenes-producing polysaccharides (also referred to as “alkathylan”), tragacanth gum, gellan gum, native gellan gum, hyaluronic acid, sodium hyaluronate, sodium chondroitin sulfate, dextrin, inulin; sorbitol, mannitol Sugar alcohols such as maltitol, lactose, maltotriitol and xylitol; inorganic salts such as sodium chloride and sodium sulfate; casein, albumin, methylation Proteins with a molecular weight exceeding 5000, such as ragen, hydrolyzed collagen, water-soluble collagen, and gelatin; glycine, alanine, valine, leucine, isoleucine, serine, threonine, aspartic acid, glutamic acid, cystine, methionine, lysine, hydroxylysine, arginine, histidine , Phenylalanine, tyrosine, tryptophan, proline, hydroxyproline, acetylhydroxyproline and other amino acids and their derivatives; synthesis of carboxyvinyl polymer, sodium polyacrylate, polyvinyl alcohol, polyethylene glycol, ethylene oxide / propylene oxide block copolymer, etc. Polymers; water-soluble cellulose derivatives such as hydroxyethyl cellulose and methyl cellulose; catechins, anthocyanins, flavones, i Flavonoids such as flavone, flavan, flavanone, rutin; ascorbic acid, sodium ascorbate, potassium ascorbate, calcium ascorbate, L-ascorbic acid phosphate, magnesium ascorbyl phosphate, sodium ascorbyl phosphate, ascorbyl sulfate, ascorbyl sulfate Ascorbic acid or derivatives thereof such as disodium salt and ascorbyl-2-glucoside; tocotrienol and derivatives thereof; chlorogenic acid, ellagic acid, gallic acid, propyl gallate, lignans, curcumins, coumarins, pterostilbene, hydroxystilbene And other functional oil phase components such as oils and fats, fatty acids, higher alcohols, oil-soluble pigments, mineral oil, and polysilicon compounds.

In addition, the composition for external use of the skin of the present invention is usually used for its purposes such as a pH adjuster, a pH buffer, an ultraviolet absorber, an antiseptic, a fragrance, a colorant, an excipient, a viscosity modifier, a radical scavenger and the like. Other additives used can be used.
Moreover, various components can be mix | blended based on the function. For example, emollient, treatment agent, lubricant, moisturizer, hair restorer, hair nourishing agent, hair growth agent, anti-whitening agent, anti-aging agent, antioxidant, fragrance, coloring agent, antiperspirant, cooling agent, cooling agent And warming agents.
Moreover, as a pharmaceutical ingredient, a hair growth agent, a hair nourishing agent, a hair growth agent, an antibiotic, a bactericidal agent, an anti-inflammatory agent, an antiallergic agent, and the like can be further included.

In addition, it is preferable that content of an oil-phase component shall be 5 mass% or less with respect to the total mass of the composition for skin external use of the composition for skin external use of this invention.
Thereby, the composition for external use of skin of this invention shows high transparency immediately after preparation, and can also maintain the transparency by storage with time.
In addition, from the viewpoint of storage stability and transparency, the composition for external skin of the present invention is such that the content of the oil phase component is 0.01 to 3% by mass relative to the total mass of the composition for external skin. Preferably, it is more preferably 0.1 to 1% by mass.

Moreover, it is preferable that content of ethanol is 10 mass% or less with respect to the total mass of the composition for external skins of the composition for external use of this invention.
Thereby, the composition for external use of skin of this invention comes to be able to ease the irritation | stimulation to skin.
Further, from the viewpoint of alleviating irritation to the skin, the composition for external use of the present invention is more preferably 0 to 5% by mass of ethanol based on the total mass of the composition for external application of skin. More preferably, it is made into 3 mass%.

The transparency of the composition for external skin of the present invention can be easily judged by visually observing the appearance, but it is more preferable to measure transparency by measuring turbidity.
Turbidity is measured as absorbance at 650 nm at 25 ° C. in a 10 mm cell using a UV-VISABLE spectral photometer UV-2550 (manufactured by Shimadzu Corporation).
In the present invention, the fact that the composition for external use on skin is transparent means that the measured value of absorbance at 650 nm is 0.1 or less. Moreover, the external composition for skin whose measured value of the light absorbency of 650 nm is 0.05 or less is more preferable.

As described above, the external composition for skin according to the present invention is excellent in storage stability.
In general, emulsion oil droplets (emulsion particles) grow and / or agglomerate during storage of the composition for external use on the skin, thereby increasing the average particle diameter of the measured emulsion particles. The transparency of the composition for external use prepared by using it is impaired.
Therefore, the storage stability of the external composition for skin can be evaluated by measuring the turbidity before and after storage of the external composition for skin.

The composition for external use of the skin of the present invention can contain a sufficient amount of pentacyclic triterpene for expression of the effect, and is excellent in transparency and storage stability. Can be used as a body cosmetic. Among them, it is preferably used as a scalp cosmetic.
There is no restriction | limiting in particular in the form of cosmetics, Cosmetics for scalp, such as skin lotion (lotion), a cosmetic liquid, and hair growth lotion, can be illustrated. From the viewpoint that the cosmetic can be uniformly applied to the target site, skin lotion and hair growth lotion are particularly preferable.

  In addition, the composition for external use of skin of this invention can be manufactured according to a well-known method. For example, an oil-in-water emulsion composition is diluted 2 to 100 times with purified water or the like so that the active ingredient concentration is 0.001% to 1%, etc., relative to the total mass of the composition for external use on the skin Can be obtained.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

<Example (1)>
(Preparation of oil-in-water emulsion composition)
β-glycyrrhetinic acid (manufactured by Maruzen Pharmaceutical Co., Ltd.) 1.00 g, N-lauroyl sarcosine isopropyl (manufactured by Ajinomoto; L-Du SL-205) 20.00 g, high-purity soybean lecithin (manufactured by Tsuji Oil; SLP-white) It melt | dissolved with stirring at 70 degreeC, and let this be an oil phase composition.
On the other hand, water obtained by dissolving 6.00 g of polyglyceryl isostearate-10 (HLB = 12) (manufactured by Nikko Chemical Co., Ltd.) in a mixed solution of 100.00 g of glycerin (manufactured by Wako Pure Chemical Industries, Ltd.) and purified water at 70 ° C. A phase composition was obtained. The amount of purified water used was appropriately adjusted so that the total mass of the prepared emulsion composition was 200 g.
Each dissolved aqueous phase composition and oil phase composition were coarsely emulsified with a TK homomixer (manufactured by Primemix) at 60 ° C. for 15 minutes at a rotation speed of 500 rpm. This coarse emulsion is passed twice at a pressure of 200 MPa while being kept at 60 ° C. with a starburst mini machine (manufactured by Sugino Machine), which is an ultra-high pressure dispersion device, to prepare a fine emulsion (oil-in-water emulsion composition). did. This was designated as Emulsion (1).
(Average oil droplet size measurement)
For the sample obtained by diluting the above emulsion (1) with purified water five times, the oil droplet (emulsion particle) size measurement is performed with Nanotrac UPA (manufactured by Nikkiso), and the volume average diameter (Mv) is obtained. It is shown in Table 1.
(Preparation of external composition for skin)
The emulsion (1) was diluted 50 times with purified water to prepare a skin external composition (1).
(Measure turbidity and evaluate turbidity change)
The turbidity at 650 nm of the external composition for skin (1) was measured as an absorbance at 650 nm at 25 ° C. using a UV-VISABLE spectrum photometer UV-2550 (manufactured by Shimadzu Corporation). The initial turbidity was 0.08.
The sample cell at this time is made of quartz glass and the optical path length is 10 mm.
Moreover, the turbidity value after leaving the composition for external use (1) in a 20 ml glass vial at 40 ° C. for 2 months was measured in the same manner as described above. The turbidity at this time was 0.08, and the turbidity change was 0.00.
Table 1 shows the initial turbidity and the turbidity change (turbidity change) after 2 months of stationary storage.

<Example (2)>
In the above Example (1), the amount of β-glycyrrhetinic acid in the oil phase composition is 2.00 g, the amount of N-lauroyl sarcosine isopropyl is 4.00 g, the amount of high-purity soybean lecithin is 4.00 g, Except that the amount of polyglyceryl isostearate-10 in the composition was 9.00 g, an emulsion was prepared in the same manner as in Example (1), and then a composition for external skin was prepared. It was.
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (3)>
In the above Example (1), the amount of β-glycyrrhetinic acid in the oil phase composition is 2.00 g, the amount of N-lauroyl sarcosine isopropyl is 7.00 g, the amount of high-purity soybean lecithin is 8.00 g, and the aqueous phase Except that the amount of polyglyceryl isostearate-10 in the composition was 9.00 g, an emulsion was prepared in the same manner as in Example (1), and then a composition for external skin was prepared. It was.
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (4)>
In Example (1), 200 g of the emulsion (1) was diluted with a mixed solvent of 744 g of purified water and 56 g of ethanol to prepare a composition for external use on skin, which was designated as composition for external use of skin (4).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (5)>
In the above Example (1), an emulsion was obtained in the same manner as in Example (1) except that polyglyceryl-10 isostearate in the aqueous phase composition was replaced with the same amount of polyglyceryl-10 oleate (HLB = 12). And the skin external composition was prepared and this was made into the skin external composition (5).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (6)>
In Example (1) above, Example (1) is the same as Example (1) except that the high-purity soybean lecithin in the oil phase composition was replaced with the same amount of hydrogenated soybean lecithin (manufactured by Sumi Oil; SLP-White H). Similarly, an emulsion and a composition for external use on the skin were prepared, and this was used as an external composition for skin (6).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (7)>
In the above Example (1), N-lauroylsarcosine isopropyl in the oil phase composition was replaced with 60.00 g of N-myristoyl-N-methyl β-alanine phytosteryl decyltetradecyl (Ajinomoto; Erduou APS307). Except for the above, an emulsion (7) was prepared in the same manner as in Example (1). Using this emulsion (7), the skin external composition was prepared like Example (1), and this was made into the skin external composition (7).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (8)>
In the above Example (1), the emulsion (8) was the same as Example (1) except that β-glycyrrhetinic acid in the oil phase composition was replaced with the same amount of asiatic acid (manufactured by Bayer Healthcare). Was prepared. Using this emulsion (8), the skin external composition was prepared like Example (1), and this was made into the skin external composition (8).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (9)>
In the above Example (1), except that β-glycyrrhetinic acid in the oil phase composition was replaced with the same amount of ursolic acid (manufactured by Sabinsa Japan), the emulsion (9) was prepared in the same manner as in Example (1). Prepared. Using this emulsion (9), the skin external composition was prepared like Example (1), and this was made into the skin external composition (9).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (10)>
In the above Example (1), except that β-glycyrrhetinic acid in the oil phase composition was replaced with the same amount of oleanolic acid (manufactured by Tokyo Chemical Industry), the emulsion (10) was prepared in the same manner as in Example (1). Prepared. Using this emulsion (10), the composition for external use of skin was prepared like Example (1), and this was made into the composition for external use of skin (10).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (11)>
In Example (1) above, 200 g of the emulsion (1) was diluted with a mixed solvent of 695 g of purified water and 105 g of ethanol to prepare an external composition for skin, which was combined with the external composition for skin (11). did.
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (12)>
In Example (7) above, except that the amount of polyglyceryl isostearate in the aqueous phase composition was 3.00 g, an emulsion was prepared in the same manner as in Example (7), and then a composition for external use on the skin was prepared. This was designated as a skin external composition (12).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Example (13)>
To 200 g of the emulsion (1) used in Example (1) above, 300 g of the following emulsion (13) is added, and this mixture is dissolved in 500 g of purified water to prepare a skin external composition. It was set as the composition (13).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).
(Preparation of emulsion (13))
An oil phase composition in which 100.00 g of ethylhexyl palmitate (manufactured by Nikko Chemical) and 10.00 g of polysorbate 40 (manufactured by Nikko Chemical) are mixed and dissolved at 70 ° C. is mixed with 190 g of purified water and roughly dispersed with a TK homomixer. After that, the emulsion (13) was obtained by passing it through a Starburst mini machine at 60 ° C. at 200 MPa three times.
<Comparative Example (14)>
In the above Example (1), N-lauroylsarcosine propyl in the oil phase composition was replaced with 70.00 g of isopropyl myristate (manufactured by Nikko Chemical Co., Ltd.) as in Example (1). 14) was prepared. Using this emulsion (14), the skin external composition was prepared like Example (1), and this was made into the skin external composition (14).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Comparative Example (15)>
In Example (1), N-lauroylsarcosine propyl in the oil phase composition was replaced with 90.00 g of medium chain fatty acid triglyceride (Nisshin Oilio; ODO). An emulsion (15) was prepared in the same manner as 1). Using this emulsion (15), the skin external composition was prepared similarly to Example (1), and this was made into the skin external composition (15).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Comparative Example (16)>
In the above Example (1), except that N-lauroyl sarcosine propyl in the oil phase composition was replaced with 90.00 g of N-lauroyl glutamate di (cholesteryl octadecyl) (Ajinomoto; Erdeu CL-202), An emulsion (16) was prepared in the same manner as in Example (1). Using this emulsion (16), a skin external composition was prepared in the same manner as in Example (1), and this was designated as skin external composition (16).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Comparative Example (17)>
In Example (1) above, except that high-purity soybean lecithin in the oil phase composition was removed, an emulsion and a composition for external skin use were prepared in the same manner as in Example (1). It was set as the external composition (17).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Comparative Example (18)>
In Example (1) above, except for high-purity soybean lecithin in the oil phase composition, except that the amount of polyglyceryl isostearate-10 in the aqueous phase composition was 9.00 g, the same as Example (1) An emulsion and a composition for external use on the skin were prepared, and this was used as an external composition for skin (18).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

<Comparative Example (19)>
In Example (7) above, except for high-purity soybean lecithin in the oil phase composition, except that the amount of polyglyceryl isostearate-10 in the aqueous phase composition was 9.00 g, the same as Example (7) Then, an emulsion and a composition for external use on the skin were prepared, and this was used as an external composition for skin (19).
In addition, the evaluation of oil droplet size and turbidity was performed in the same manner as in Example (1).

  The thus obtained (initial) oil droplet volume average size (denoted as “oil droplet size” in the table), the turbidity value at 650 nm of the (initial) external composition for skin (in the table, “initial” Table 1 and Table 2 below show the change in turbidity (denoted as “turbidity change” in the table) after storage at 40 ° C. for 2 months. In the table, “(amount)” represents the content (mass%) of each component with respect to the total mass of the composition for external use on skin.

From this result, it was revealed that the emulsion composition of the present invention has high initial transparency. Moreover, it became clear that the external composition for skin containing the emulsion composition of this invention has a small turbidity change at the time of a preservation | save.
In addition, when the composition for external skin was prepared, when the ethanol concentration contained in the composition for external skin was high, it became clear that the turbidity change at the time of storage tends to be prominent. Moreover, when the density | concentration of the oil phase component contained in the composition for external use of skin was high, it became clear that the transparency of the composition for external use of skin tends to fall by the increase in initial turbidity.

The disclosure of Japanese Patent Application No. 2013-008700 filed on January 21, 2013 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

Claims (14)

(A) a pentacyclic triterpene, (b) an N-acylamino acid monoester, and (c) an oil phase containing lecithin, and an aqueous phase containing a polyglycerol fatty acid ester of HLB 10-16 ,
(B) N-acylamino acid monoester is a compound comprising a neutral amino acid residue, an alkylacyl group bonded to the N-position of the neutral amino acid residue, and an alkylester moiety;
The alkyl acyl group is a saturated or unsaturated alkyl acyl group having a straight chain or branched chain having 6 to 22 carbon atoms;
The oil- in- water emulsion composition, wherein the alkyl ester moiety is an ester moiety containing a linear or branched chain having 1 to 40 carbon atoms or a cyclic alkyl group having 3 to 30 carbon atoms . The oil-in-water emulsion according to claim 1, wherein the neutral amino acid is a neutral amino acid selected from the group consisting of glycine, alanine, β-alanine, aminobutyric acid, aminopropionic acid, sarcosine, and N-methyl-β-alanine. Composition. (A) The oil-in-water emulsion composition according to claim 1 or 2 , wherein the pentacyclic triterpene is a pentacyclic triterpene having a carboxyl group. The oil-in-water emulsion composition according to any one of claims 1 to 3 , wherein (a) the pentacyclic triterpene is glycyrrhetinic acid. (B) The N-acylamino acid monoester is an N-acylamino acid monoalkyl ester, and an amino acid selected from the group consisting of sarcosine, alanine, glycine and N-methyl-β-alanine is converted to N-caproylated, N- Lauroylation, N-myristylation, N-palmitoylation, N-stearoylation, N-behenoylation, or N-cocoylation partial structure, branched or straight chain corresponding to the alkyl part of ester, and having 2 carbon atoms The oil-in-water emulsion composition according to any one of claims 1 to 4 , which has an alkyl partial structure having an alkyl chain length of -8. (B) The oil-in-water emulsion composition according to any one of claims 1 to 5 , wherein the N-acylamino acid monoester is N-lauroyl sarcosine isopropyl. (C) The lecithin is soybean lecithin. The oil-in-water emulsion composition according to any one of claims 1 to 6 . (C) the content of lecithin, (a) the total weight of the 5 triterpenes and (b) N-acylamino acid monoester, a 2% by mass to 50% of claims 1 to 7 The oil-in-water emulsion composition according to any one of the above. Polyglycerol fatty acid esters HLB10~16 is, polyglycerol monooleate, claims 1 is at least one compound selected from the group consisting of polyglycerol monostearate and polyglycerol monoisostearate ester 8 The oil-in-water emulsion composition according to any one of the above.   The oil-in-water emulsion composition according to any one of claims 1 to 9, comprising emulsion particles having an average particle size of 20 nm to 150 nm.   An external composition for skin containing the oil-in-water emulsion composition according to any one of claims 1 to 10.   The external composition for skin according to claim 11, wherein the total amount of the oil phase component is 5% by mass or less based on the total mass of the external composition for skin.   The composition for external skin according to claim 11 or 12, wherein the content of ethanol is 10% by mass or less based on the total mass of the composition for external skin.   A scalp cosmetic containing the external composition for skin according to any one of claims 11 to 13.