Composition containing lipid membrane structure and method for producing the same

Abstract

To provide compositions containing lipid membrane structures to enable easy preparation of minute lipid membrane structures and production methods thereof.SOLUTION: The composition containing lipid membrane structures contains: (a) a phospholipid whose PC content is 55 mass% or more; (b) one or more components selected from (ascorbyl / tocopheryl) phosphate and a salt thereof and anionic surfactants; (c) a C5-C6 alkanediol, where the mass ratio of the component (a) and the component (b) is from 80:20 to 99:1; the component (a) is a hydrogenated phospholipid; and the component (b) is one or more components selected from (ascorbyl / tocopheryl) phosphate, N-acylamino acid salt, fatty acid salt, N-acyltaurine salt and alkyl sulfate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composition containing lipid membrane structures, which is used in cosmetics, external skin preparations, etc., and a method for producing the same. [Background technology]

[0002] Lipid membrane structures are widely used in fields such as cosmetics. Examples of lipid membrane structures include bicelles and liposomes. Bicelles are considered to be the smallest lipid bilayer membrane model and have a disc-shaped, single-lamellar structure. Liposomes, on the other hand, are spherical, closed endoplasmic reticulum composed of a lipid bilayer membrane. These lipid membrane structures have skin care effects such as moisturizing, and can also encapsulate active ingredients.

[0003] A liposome-containing composition disclosed in Patent Document 1 has been known as a composition that is incorporated into skin cosmetics, for example. The composition contains phospholipids, ceramides, and a branched alcohol, and the flexibility of the liposome membrane is enhanced. The improved flexibility allows the liposome shape to be maintained without collapse, resulting in excellent storage stability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-032230 Summary of the Invention [Problem to be solved by the invention]

[0005] In preparing lipid membrane structures, emulsification using a high-pressure homogenizer or similar is generally required to form fine lipid membrane structures. However, this method tends to increase workability and costs. Meanwhile, the Bangham method is known as a method for preparing bicelles, which are lipid membrane structures. However, because this method uses organic solvents such as chloroform, the organic solvent must be removed during the manufacturing process, making it unsuitable for mass production.

[0006] An object of the present invention is to provide a composition containing lipid membrane structures that allows fine lipid membrane structures to be easily obtained, and a method for producing the same. [Means for solving the problem]

[0007] The composition containing the lipid membrane structure of the present invention (hereinafter simply referred to as the composition) comprises: (a) Phospholipids containing 55% or more PC by mass (b) one or more surfactants selected from (ascorbyl / tocopheryl) phosphate and its salts, and anionic surfactants (c) Alkanediols with 5 to 6 carbon atoms Contains The mass ratio of the component (a) to the component (b) is 80:20 to 99:1.

[0008] The component (a) is a hydrogenated phospholipid, and the component (a) has an acid value of less than 5 mg KOH / g.

[0009] The component (b) is characterized in that it is one or more selected from the group consisting of (ascorbyl / tocopheryl) phosphates, N-acylamino acid salts, fatty acid salts, N-acyltaurine salts, and alkyl sulfates.

[0010] The component (b) is one or more selected from N-acylamino acid salts and N-acyltaurine salts, and is characterized by having an acyl group derived from a fatty acid having 14 to 18 carbon atoms.

[0011] Furthermore, it is characterized by containing glycerin as component (d).

[0012] Furthermore, the composition is characterized in that it contains, as component (e), one or more selected from phytosterol, cholesterol, phytosteryl ester, and cholesteryl ester.

[0013] The mass ratio ((e) / (a)) of the component (e) to the component (a) is 1 / 100 to 1 / 50.

[0014] The composition containing the lipid membrane structure is a cosmetic or an external skin preparation.

[0015] The production method of the present invention is a method for producing the lipid membrane structure of the present invention, characterized in that the lipid membrane structure is obtained by heating and dissolving the above-mentioned components (a), (b), and (c), and then mixing and stirring the resultant with water. [Effects of the Invention]

[0016] Since the composition of the present invention contains the above-mentioned components (a) to (c), emulsification using a micronization means such as a high-pressure homogenizer is not required, and removal of the organic solvent is also not required. Therefore, a composition containing fine lipid membrane structures can be easily obtained. Furthermore, the composition of the present invention is useful as a cosmetic or topical skin preparation. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a photograph of the composition of Example 1-1 observed with a transmission electron microscope. [Figure 2] 1 is a photograph of the composition of Example 2-4 observed with a transmission electron microscope. [Figure 3] 1 is a photograph of the composition of Example 11 observed with a transmission electron microscope. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be described in detail below. In this specification, the symbol "to" means a range including the numerical values ​​before and after it.

[0019] <Component (a)> Component (a) in the present invention is a phospholipid having a PC (phosphatidylcholine) content of 55% by mass or more. From the viewpoint of forming a lipid membrane structure, a higher PC content is preferable, specifically, a PC content of 65% by mass or more is preferable, and a PC content of 75% by mass or more is more preferable. The PC content is, for example, 99.5% by mass or less.

[0020] Examples of phospholipids include natural phospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, lysophosphatidylcholine, sphingomyelin, egg yolk lecithin, and soybean lecithin; synthetic phospholipids such as dilauroylphosphatidylcholine and dimyristoylphosphatidylcholine; and hydrogenated phospholipids such as hydrogenated soybean lecithin, hydrogenated egg yolk lecithin, hydrogenated phosphatidylcholine, and hydrogenated phosphatidylserine. These may be used alone or in combination. When two or more types are used, the combined phospholipids may have a total PC content of 55% by mass or more, and some of the phospholipids constituting component (a) may contain less than 55% by mass of phospholipids.

[0021] From the viewpoint of storage stability, component (a) preferably contains a hydrogenated phospholipid, and more preferably contains a hydrogenated soybean phospholipid.

[0022] The acid value of component (a) (the value for all phospholipids when two or more types of phospholipids are used) is not particularly limited, and can be, for example, less than 15 mg KOH / g or less than 5 mg KOH / g. The acid value is the number of milligrams of potassium hydroxide (KOH) required to neutralize 1 g of sample. The acid value can be measured according to the general test method, oil and fat test method, acid value of the Japanese Pharmacopoeia (17th edition).

[0023] The content of component (a) is not particularly limited, but from the viewpoint of storage stability and dispersibility, it is preferably 0.05 to 3 mass % of the total amount of the composition, more preferably 0.05 to 2 mass %, and even more preferably 0.1 to 1.5 mass %.

[0024] <Ingredient (b)> The component (b) in the present invention is one or more selected from (ascorbyl / tocopheryl) phosphate and its salts, and anionic surfactants.

[0025] Ascorbyl / tocopheryl phosphate and its salts have a variety of functions, including antioxidant activity, active oxygen scavenging activity, moisturizing activity, and normalization of the stratum corneum regeneration cycle. For example, EPC (SENJU) manufactured by Senju Pharmaceutical Co., Ltd. is a commercially available ascorbyl / tocopheryl phosphate salt. EPC (SENJU) is an alkali metal salt containing 1 to 2 moles of potassium per mole of dl-α-tocopherol 2-L-ascorbic acid phosphate diester.

[0026] Anionic surfactants are a general term for surfactants having an anionic hydrophilic group, and examples of surfactants that can be used include carboxylic acid surfactants, phosphate ester surfactants, sulfate surfactants, and sulfonic acid surfactants.

[0027] Carboxylic acid surfactants are surfactants having one or more carboxyl groups in the molecule. Examples of carboxylic acid surfactants include N-acylamino acids, alkyl ether carboxylic acids, polyoxyethylene alkyl ether carboxylic acids, N-acylmethylalanines, diacylamino acids and their salts, and fatty acid salts. Examples of counter ions of the salts include alkali metals (sodium, potassium, etc.), alkaline earth metals (calcium, magnesium, etc.), and ammonium. The counter ions of the salts are similar to those of the other surfactants described below.

[0028] Phosphate ester surfactants are surfactants that have one or more phosphate ester bonds in the molecule, such as alkyl phosphate esters, polyoxyethylene alkyl ether phosphate esters, polyoxyethylene alkyl phenyl ether phosphate esters, and salts thereof.

[0029] Examples of sulfate-type surfactants include alkyl sulfate esters, polyoxyethylene alkyl sulfate esters, alkyl ether sulfates, polyoxyethylene alkyl ether sulfates, and salts thereof.

[0030] Sulfonic acid surfactants are surfactants having a sulfonic acid group, such as alkanesulfonic acids, alkylbenzenesulfonic acids, α-olefinsulfonic acids, α-sulfofatty acid methyl esters, N-acyltaurines, and salts thereof.

[0031] In particular, component (b) preferably contains one or more selected from (ascorbyl / tocopheryl) phosphates, N-acylamino acid salts, fatty acid salts, N-acyltaurine salts, and alkyl sulfates. Furthermore, in the case of N-acylamino acid salts and N-acyltaurine salts, it is preferable that the molecular structure contains an acyl group derived from a fatty acid having 14 to 18 carbon atoms.

[0032] Examples of N-acylamino acid salts include N-acylglutamates such as N-lauroyl-L-glutamate, N-myristoyl-L-glutamate, N-stearoyl-L-glutamate, N-coconut oil fatty acid acyl-L-glutamate, and N-acyl-L-glutamate, N-acylglycine salts such as N-coconut oil fatty acid acylglycine, and N-acylsarcosine salts such as lauroylsarcosine, myristoylmethylaminoacetate, and palmitoylsarcosine. Examples of fatty acid salts include myristate, laurate, palmitate, stearate, and oleate.

[0033] Examples of N-acyltaurate salts include lauroyl methyl taurine, myristoyl methyl taurine, N-stearoyl-N-methyl taurine, etc. Examples of alkyl sulfate salts include lauryl sulfate, myristyl sulfate, cetyl sulfate, and hydrogenated coconut oil fatty acid glyceryl sulfate.

[0034] The content of component (b) is not particularly limited, but is preferably 0.005 to 0.5 mass % relative to the total amount of the composition, more preferably 0.01 to 0.3 mass %, and even more preferably 0.01 to 0.05 mass %.

[0035] In the present invention, the mass ratio of component (a) to component (b) is 80:20 to 99:1. When the content of component (b) relative to the content of component (a) exceeds a certain level, it tends to become difficult to form lipid membrane structures. The mass ratio is preferably 90:10 to 99:1, and more preferably 90:10 to 95:5.

[0036] <Ingredient (c)> Component (c) in the present invention is an alkanediol having 5 to 6 carbon atoms. This alkanediol has a structure in which two hydroxyl groups are added to a linear or branched alkane having 5 to 6 carbon atoms. As will be shown in the examples below, when the carbon number is 4 or less or 7 or more, it is difficult to form a fine lipid membrane structure.

[0037] Examples of alkanediols having 5 to 6 carbon atoms include 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, isopentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, etc. Among these, it is preferable to use one or two selected from 1,2-pentanediol and 1,2-hexanediol.

[0038] The content of component (c) is not particularly limited, but is preferably 1 to 5 mass % and more preferably 2 to 5 mass % based on the total amount of the composition.

[0039] <Ingredient (d)> The composition of the present invention may further contain glycerin as component (d). The content of glycerin is preferably 1 to 5 mass% and more preferably 2 to 5 mass% of the total amount of the composition. Furthermore, it is preferable that component (d) is contained in the same amount as component (c). Specifically, the mass ratio of component (d) to component (c) is preferably 40:60 to 60:40 and more preferably 45:55 to 55:45.

[0040] <Ingredient (e)> The composition of the present invention may further contain a fat-soluble compound as component (e). Examples of fat-soluble compounds include sterols such as phytosterol and cholesterol; sterol esters such as phytosteryl ester and cholesteryl ester; higher fatty acids such as oleic acid and behenic acid; ceramides such as ceramide EOS, ceramide NG (ceramide 2), and ceramide NP (ceramide 3); fat-soluble vitamins such as retinol and tocopherol; and hydrocarbons such as limonene, petrolatum, and squalane. Sterols and ceramides are also known as active ingredients for improving the skin's barrier function.

[0041] Phytosterols are a type of sterol, also known as plant sterols. Examples of phytosterols include β-sitosterol, campesterol, stigmasterol, and brassicasterol. Cholesterol is also a type of sterol.

[0042] Phytosteryl esters can be obtained, for example, by esterifying fatty acids with phytosterol. Examples of fatty acids include fatty acids having 4 to 32 carbon atoms. Specific examples include butyric acid, caproic acid, caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, and linolenic acid. In addition, fatty acids may be used as mixtures extracted from natural products, such as lanolin acid and macadamia nut fatty acids, or hydroxyl fatty acids such as hydroxystearic acid and amino acid derivatives such as N-lauroylglutamic acid.

[0043] Cholesteryl esters can be obtained, for example, by esterifying fatty acids with cholesterol. Examples of fatty acids include the above-mentioned fatty acids having 4 to 32 carbon atoms. Furthermore, mixtures of fatty acids extracted from natural products, such as lanolin acid and macadamia nut fatty acids, may also be used. Furthermore, hydroxyl fatty acids such as hydroxystearic acid and amino acid derivatives such as N-lauroyl glutamic acid may also be used.

[0044] One or more of the phytosterols, cholesterol, phytosteryl esters, and cholesteryl esters may be used. For example, a commercially available sterol ester mixture may be used.

[0045] The content of component (e) is preferably 0.001 to 3 mass%, more preferably 0.005 to 1 mass%, and even more preferably 0.005 to 0.5 mass%, based on the total amount of the composition. The mass ratio of component (e) to component (a) ((e) / (a)) is preferably 1 / 100 to 1 / 10, and more preferably 1 / 100 to 1 / 50.

[0046] <Component (f)> The composition of the present invention may further contain water as component (f). In this case, component (f) is used as a dispersion medium for lipid membrane structures. Component (f) can be any component commonly used in the fields of cosmetics, pharmaceuticals, etc., and is not particularly limited. For example, purified water, tap water, hot spring water, deep sea water, etc. can be used as component (f), and one or more of these can be used as appropriate. The content of component (f) is not particularly limited, but is preferably 70 to 95% by mass, more preferably 80 to 95% by mass.

[0047] <Ingredients (g)> The composition of the present invention may further contain a polyhydric alcohol other than components (c) and (d) as component (g). Component (g) functions as a solvent for the oily components during the preparation of the composition. For example, one or more alcohols selected from propylene glycol, dipropylene glycol, and 1,3-butylene glycol can be used as component (g).

[0048] The content of component (g) is not particularly limited, but is preferably 3 to 20 mass % and more preferably 3 to 10 mass % relative to the total amount of the composition.

[0049] In addition to the above components (a) to (g), the composition of the present invention may also contain other optional components that are typically incorporated into cosmetics and topical skin preparations, such as oils, water-soluble polymers, amino acids, organic acids, inorganic salts, chelating agents, preservatives, pH adjusters, pigments, and water-soluble drugs, if necessary.

[0050] The composition of the present invention contains lipid membrane structures. Lipid membrane structures refer to particles having a lipid bilayer (lamella) structure, in which lipid molecules are arranged with their hydrophilic groups facing outward and their hydrophobic groups facing inward. Specific forms of lipid membrane structures include liposomes and bicelles. The composition of the present invention may contain a mixture of liposomes and bicelles, and the lamellar structure may be composed of a single layer or multiple layers.

[0051] In the present invention, the formation of lipid membrane structures can be finally confirmed using a transmission electron microscope (TEM). However, in the examples described below, from the viewpoint of screening, the formation of lipid membrane structures is primarily determined by the average particle diameter measured using a dynamic light scattering measurement device. Specifically, it is determined that lipid membrane structures have been formed when the average particle diameter is 200 nm or less. From the viewpoints of dispersibility and skin permeability, the average particle diameter is preferably 150 nm or less, more preferably 100 nm or less, and even more preferably 80 nm or less. Furthermore, the average particle diameter is, for example, 15 nm or more. In the present invention, the average particle diameter of lipid membrane structures is determined in accordance with JIS Z8826:2005, particle size analysis - photon correlation spectroscopy.

[0052] In the present invention, the lipid membrane structure preferably contains a unilamellar structure, and more preferably contains a bicelle. Bicelles are fine, disc-shaped unilamellar structures that are excellent in compound encapsulation efficiency and skin permeability. The formation of bicelles can be confirmed by observing disc images using a transmission electron microscope (TEM). When the composition contains bicelles, the proportion of bicelles (number of disc images / total number of particle images in the field of view observed by the electron microscope) is preferably 50% or more, and more preferably 80% or more.

[0053] The composition of the present invention is preferably transparent from the viewpoint of appearance and storage stability. This transparency can be evaluated by the transmittance measured at a specific wavelength using an ultraviolet-visible spectrophotometer, as shown in the examples described below. The transmittance of the composition of the present invention is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more.

[0054] The composition of the present invention can be obtained by heating and dissolving components (a), (b), and (c) (and, if necessary, components (d) and / or (e)), adding the resulting solution to a heated aqueous phase while mixing and stirring, and optionally purifying and cooling the mixture. The aqueous phase contains component (f) (and, if necessary, component (g)). The heating temperature is not particularly limited, but is preferably 50 to 90°C, more preferably 70 to 90°C. The mixing time is, for example, about 1 to 30 minutes.

[0055] The mixing means used for mixing is not particularly limited, and conventional mixing means such as a magnetic stirrer such as a hot stirrer, a paddle mixer, or a propeller mixer can be used. Stirring and mixing using these mixing means is performed under non-pressurized conditions and does not require high mechanical shear force. As described above, in the present invention, by combining specific components, fine lipid membrane structures can be easily formed without using micronization means such as a high-pressure homogenizer.

[0056] The composition of the present invention may be used as a cosmetic or topical skin preparation as it is, or may be prepared and then combined with other ingredients to be used as a cosmetic or topical skin preparation. The dosage form is not particularly limited, and may be, for example, a gel, paste, liquid, cream, solid, or other dosage form. [Example]

[0057] The present invention will be specifically explained below by way of examples, but the present invention is not limited to these examples in any way.

[0058] Compositions having the compositions shown in Tables 1 to 11 were prepared. Specifically, phase A and phase B were each weighed and dissolved by heating at 80°C. Phase B was then heated with a hot stirrer while being stirred with a stirrer, and phase A was gradually added thereto. After the entire amount of phase A was added, the mixture was stirred for about 1 minute. The mixture was then cooled with water to 35°C while being stirred with a stirring rod, to obtain a composition.

[0059] <Average particle size> The average particle size of the particles in the obtained composition was measured using a dynamic light scattering measurement device (Zetasizer Nano ZS). The average particle size (Z-Average) obtained by cumulant analysis was used as the average particle size. In the examples, it was determined that lipid membrane structures had been formed when the average particle size was 200 nm or less. Furthermore, in some examples, the formation of lipid membrane structures was actually confirmed using TEM. The results are shown in Tables 1 to 11.

[0060] <Transmittance> To evaluate the transparency of the resulting compositions, the transmittance at a wavelength of 700 nm was measured using an ultraviolet-visible spectrophotometer (UV-1600). The results are shown in Tables 1 to 11.

[0061] First, each of the components (a), (b), and (c) was examined in Tables 1 to 4. In Tables 1 to 4, the components other than the examined components and their blending amounts are the same.

[0062] [Table 1]

[0063] In Table 1, the phospholipids of component (a) were examined. As shown in Table 1, lipid membrane structures were formed when the PC content was 55% by mass or more. Furthermore, as the PC content increased, the average particle size tended to increase and the transmittance tended to decrease. When the appearance of the compositions of Examples 1-1 to 1-5 was observed, all of them exhibited a microemulsion-like appearance. In Table 1, the acid value of the hydrogenated soybean phospholipid with a PC content of 90% was less than 5 mg KOH / g, and the acid value of the hydrogenated soybean phospholipid with a PC content of 75 to 85% was 10 mg KOH / g or more and less than 15 mg KOH / g. The composition of Example 1-1 was observed under a microscope using a transmission electron microscope (JEM-1400Plus). The photograph is shown in Figure 1. As shown in Figure 1, many rod-shaped images were observed, confirming the formation of bicelles.

[0064] [Table 2]

[0065] [Table 3]

[0066] Tables 2 and 3 examine the anionic surfactant of component (b). As shown in Table 2, when the composition did not contain component (b) (Comparative Example 2-1), lipid membrane structures were not formed. The results in Tables 2 and 3 show that lipid membrane structures were formed by combining (ascorbyl / tocopheryl) phosphate, or a carboxylic acid, sulfate, or sulfonic acid anionic surfactant with component (a) and component (c). Furthermore, when the composition of Example 2-4 was observed using a transmission electron microscope, the formation of bicelles was confirmed (see FIG. 2). Similarly, the formation of bicelles was also confirmed by microscopic observation of the composition of Example 3-2.

[0067] [Table 4]

[0068] Polyhydric alcohols as component (c) were examined in Table 4. As shown in Table 4, lipid membrane structures were formed when 1,2-pentanediol and 1,2-hexanediol were used as component (c) (Examples 4-1 and 4-2). On the other hand, when the carbon number was 4 or less (Comparative Examples 4-1 and 4-2), the average particle size increased and the transmittance also decreased significantly. When the carbon number was 7 or more (Comparative Example 4-5), a precipitate formed and the composition separated. Furthermore, even when the carbon number was 6, the average particle size increased when an ether bond was present in the side chain (Comparative Examples 4-3 and 4-4).

[0069] Next, the mass ratio of component (a) to component (b) was examined in Tables 5 and 6. Potassium (ascorbyl / tocopheryl) phosphate was used as component (b). In Tables 5 and 6 (including Tables 7 to 11 described below), only purified water (f) was used as phase B.

[0070] [Table 5]

[0071] As shown in Table 5, fine lipid membrane structures were formed when the mass ratio of component (a) to component (b) was 80:20 to 99:1. Furthermore, within that mass ratio range, the larger the content ratio of component (b) to component (a), the smaller the average particle size tended to be. On the other hand, when the mass ratio of component (a) to component (b) was 70:30 (Comparative Example 5-1), the average particle size became larger. Furthermore, when glycerin, component (d), was added (Examples 5-6 to 5-8), almost no effect on the average particle size and transmittance was observed. Furthermore, for the compositions of Examples 5-2 to 5-5, the formation of bicelles was confirmed by microscopic observation.

[0072] [Table 6]

[0073] In Table 6, the mass ratio was investigated by fixing the content of (b) potassium (ascorbyl / tocopheryl) phosphate at 0.035% by mass and varying the content of (a) phospholipid from 0.4 to 1% by mass. As shown in Examples 6-1 to 6-7, within the mass ratio (a:b) range of approximately 97:3 to 92:8, the average particle size tended to decrease as the content ratio of component (b) to component (a) increased. Furthermore, the transmittance increased as the average particle size decreased. Furthermore, for the compositions of Examples 6-8 and 6-9, the formation of bicelles was confirmed by microscopic observation.

[0074] Next, the fat-soluble compound of component (e) was examined in Tables 7 to 10. Specifically, the content of (a) phospholipid was fixed at 0.7% by mass, and the mass ratio of component (e) to component (a) was examined in the range of 1 / 700 to 1 / 5.

[0075] [Table 7]

[0076] In Table 7, a cholesteric liquid crystal was used as component (e). The sterol ester mixture in Table 7 is a mixture of dihydrocholesteryl oleate, cholesteryl nonanoate, dihydrocholesteryl butyrate, cholesteryl butyrate, and phytosteryl oleate. In other words, the composition shown in Table 7 uses a mixture of phytosteryl ester and cholesteryl ester as component (e). As shown in Table 7, when the mass ratio ((e) / (a)) was in the range of 1 / 100 to 1 / 14, both the average particle size and the transmittance were good and no significant differences were observed. On the other hand, in the visual observation, oil floating was observed in Examples 7-6 to 7-8, and a decrease in uniformity was confirmed. Furthermore, for the composition of Example 7-5, the formation of bicelles was confirmed by microscopic observation.

[0077] [Table 8]

[0078] Phytosterol was used as component (e) in Table 8. Table 8 shows that, within the mass ratio ((e) / (a)) range of 1 / 70 to 1 / 5, the average particle size tends to increase and the transmittance tends to decrease as the content ratio of component (e) to component (a) increases. Furthermore, for the compositions of Examples 8-3, 8-5, and 8-6, the formation of bicelles was confirmed by microscopic observation.

[0079] [Table 9]

[0080] In Table 9, cholesterol was used as component (e). In Table 9, the same results as in Table 8 were obtained.

[0081] [Table 10]

[0082] In Table 10, higher fatty acids, ceramides, and hydrocarbons were used as component (e). Table 10 also shows a tendency that as the mass ratio ((e) / (a)) increases, the average particle size increases and the transmittance decreases. Furthermore, for the composition of Example 10-9, the formation of bicelles was confirmed by microscopic observation.

[0083] Next, two types of compositions were compared using a manufacturing method using a hot stirrer (Method A) and a manufacturing method using a high-pressure homogenizer (emulsifying and dispersing device) (Method B). The manufacturing method using a hot stirrer is a manufacturing method in which phases A and B are stirred normally, as described above. Meanwhile, the manufacturing method using a high-pressure homogenizer is a manufacturing method in which phases A (and B) are stirred using a microfluidizer. The results are shown in Table 11.

[0084] [Table 11]

[0085] As shown in Table 11, in Example 11, results obtained using the hot stirrer were comparable to those obtained using the high-pressure homogenizer. In particular, the hot stirrer produced superior results in terms of transmittance. Furthermore, when the compositions obtained by Method A and Method B in Example 11 were observed using a transmission electron microscope, bicelles were confirmed to have formed. For reference, FIG. 3 shows a micrograph of the composition obtained by Method B. On the other hand, in Comparative Example 11, which did not contain component (c), lipid membrane structures were not formed by normal stirring, but lipid membrane structures were formed by using a high-pressure homogenizer.

[0086] The results of the above examples demonstrate that, according to the present invention, by using at least components (a) to (c) in combination, fine lipid membrane structures can be easily formed without using micronization means such as a high-pressure homogenizer.

Claims

1. (a) a phospholipid having a PC content of 55% by mass or more (b) one or more surfactants selected from (ascorbyl / tocopheryl) phosphate and its salts, and anionic surfactants (c) one or two selected from 1,2-pentanediol and 1,2-hexanediol Contains the mass ratio of the component (a) to the component (b) is 90:10 to 99:1; The component (a) has an acid value of less than 5 mg KOH / g, the component (b) is one or more selected from the group consisting of (ascorbyl / tocopheryl) phosphates, N-acylamino acid salts, fatty acid salts, N-acyltaurine salts, and alkyl sulfates; The composition containing a lipid membrane structure further contains, as component (e), one or more selected from phytosterol, cholesterol, phytosteryl ester, and cholesteryl ester, and the mass ratio of component (e) to component (a) ((e) / (a)) is 1 / 100 to 1 / 50.

2. 2. The composition containing lipid membrane structures according to claim 1, wherein the component (a) is a hydrogenated phospholipid.

3. 3. The composition containing lipid membrane structures according to claim 1, wherein the component (b) is one or more selected from N-acylamino acid salts and N-acyltaurine salts, and has an acyl group derived from a fatty acid having 14 to 18 carbon atoms.

4. 4. The composition comprising the lipid membrane structure according to claim 1, further comprising glycerin as a component (d).

5. A composition comprising the lipid membrane structure according to any one of claims 1 to 4, which is a cosmetic or an external skin preparation.

6. A method for producing a composition containing the lipid membrane structure according to any one of claims 1 to 3, comprising: A method for producing a composition containing lipid membrane structures, comprising heating and dissolving the components (a), (b), (c), and (e), and then mixing and stirring the resulting mixture with water.

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