Topical skin components

Abstract

To provide an external composition for the skin having high emollient feeling which has both a barrier function by liposomes and penetration feeling by a bicell structure.SOLUTION: An external composition for the skin contains liposomes and a bicell structure, where liposomes contain component (A) phospholipid, component (B) phytosterol, component (C) polyhydric alcohol with an IOB value of 2.0 to 5.0, the bicell structure contains component (D) phospholipid, component (E) ceramides, component (F) at least one kind of surfactant selected from the group consisting of polyoxyethylene sterol ether, polyoxyethylene stanol ether, and polyglyceryl fatty acid ester bing an ester of polyglycerol with an average addition molar number of 5 to 20 and fatty acid with a carbon number of 10 to 22, and component (G) at least one kind of dihydric alcohol selected from the group consisting of propylene glycol, dipropylene glycol, and 1,3- butylene glycol.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for external use on the skin.

Background Art

[0002] Liposomes, which are closed vesicles of phospholipids, are widely used as skin care substrates for delivering active ingredients and achieving stratum corneum retention effects in the pharmaceutical and cosmetic fields. In recent years, in the cosmetic field, higher skin care effects and a wide range of texture selections have been demanded, and various attempts have been made (see, for example, Patent Documents 1 and 2). On the other hand, a bicelle structure (see, for example, Patent Document 3) is a disk-shaped molecular aggregate in which the ends of a bilayer flat membrane composed of long-chain phospholipids are covered with a surfactant such as a short-chain phospholipid. It has been used in the study of biological membranes as the simplest lipid bilayer membrane model. In recent years, it has also been known that applying a bicelle structure to the skin can penetrate into the stratum corneum and affect the lamellar structure of the stratum corneum, and it has begun to attract attention as a carrier.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Therefore, in pursuit of a new texture, we attempted to create a topical skin composition by combining liposomes and bicell structures. However, collisions between the two particles sometimes altered the particle morphology of both the liposomes and bicell structures, raising concerns about the composition's storage stability and maintaining a good texture. Thus, it was necessary to ensure that both particles could coexist stably over a long period of time. Therefore, the present invention aims to provide a highly emollient topical skin composition that combines the barrier function of liposomes and the penetrating sensation of bicell structures, by ensuring that both the liposome and bicell structures remain stable over a long period of time. [Means for solving the problem]

[0005] In light of these circumstances, the inventors diligently conducted research and, as a result, investigated the composition of liposomes and bicelle structures, thereby completing the present invention.

[0006] In other words, the present invention relates to the following: [1] A topical skin composition containing liposomes and a bicell structure, The liposome is a liposome containing component (A) phospholipid, component (B) phytosterol, and component (C) polyhydric alcohol with an IOB value of 2.0 to 5.0. The bicell structure contains at least one surfactant selected from the group consisting of component (D) phospholipids, component (E) ceramides, component (F) polyoxyethylene sterol ethers, polyoxyethylene stanol ethers, and polyglycerol fatty acid esters which are esters of polyglycerol with an average addition number of 5 to 20 and fatty acids having 10 to 22 carbon atoms, and component (G) at least one dihydric alcohol selected from the group consisting of propylene glycol, dipropylene glycol, and 1,3-butylene glycol, wherein the mass ratio of component (D) to component (F) (D) / (F) is 0.2 to 1.6, and the mass ratio of component (E) to the sum of component (D) and component (F) (E) / {(D)+(F)} is 0.1 to 0.8. Furthermore, the topical skin composition is such that the total amount of components (A) and (B) in the liposome and the total amount of components (D) to (F) of the bicell structure are in a mass ratio of 200:1 to 1:1. [2] The topical skin composition according to [1] further comprising component (H) an anionic polymer. [3] The topical skin composition according to [1] or [2], wherein component (H) contains one or more selected from carboxyvinyl polymers and / or alkyl-modified carboxyvinyl polymers. [Effects of the Invention]

[0007] The topical skin composition of the present invention exhibits excellent coexistence stability between liposomes and bicell structures, resulting in good penetration and film-forming properties when applied to the skin, and superior firmness after repeated use. Therefore, the topical skin composition of the present invention is useful as a skincare cosmetic, anti-aging cosmetic, etc., with high emollient effects. [Best Mode for Carrying Out the Invention]

[0008] Embodiments of the present invention will be described below. However, the present invention is not limited to the embodiments described below. In this specification, "X~Y" indicating a range includes X and Y, and means "X or greater and Y or less".

[0009] (Liposomes) In this specification, "liposome" refers to a spherical, closed vesicle having a lipid bilayer membrane, dispersed in an aqueous solvent. A liposome dispersion is obtained by dispersing components (A) to (C) in an aqueous solvent. A Malthese cross pattern is observed when the dispersion is observed under a polarized light microscope.

[0010] (Component (A): Phospholipids) The component (A) phospholipid used in the liposomes of the present invention is a lipid having a phosphate ester moiety in its molecular structure. Specifically, examples include phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, and phosphatidic acid. Among these, phosphatidylcholine and phosphatidylethanolamine are preferred from the viewpoint of the stability of the liposome composition, and phosphatidylcholine (PC) is more preferred. Specifically, a mixture of the above phospholipids, whose composition differs depending on their origin, can be used. It is not particularly limited as long as it is used in ordinary cosmetics, quasi-drugs, pharmaceuticals, etc. Examples include soybean-derived phospholipids, soybean-derived hydrogenated phospholipids, soybean-derived lysophospholipids, soybean-derived hydrogenated lysophospholipids, egg yolk-derived phospholipids, egg yolk-derived hydrogenated phospholipids, egg yolk-derived lysophospholipids, and egg yolk-derived hydrogenated lysophospholipids. One or more of these can be used as needed. From the viewpoint of stability, preferred candidates include soybean-derived hydrogenated phospholipids, soybean-derived hydrogenated lysophospholipids, egg yolk-derived hydrogenated phospholipids, and egg yolk-derived hydrogenated lysophospholipids, and more preferably soybean-derived hydrogenated phospholipids and soybean-derived hydrogenated lysophospholipids. Among these, from the viewpoint of liposome stability, those with high PC purity (preferably 70% by mass or more) can be used. Specifically, commercially available products such as NIKKOL Lesinol S-10E (manufactured by Nikko Chemicals Co., Ltd.), Basis LS-60HR (manufactured by Nisshin Oillio Group Co., Ltd.), egg yolk lecithin PL-100P (manufactured by Kewpie Corporation), and HSL-70 (manufactured by YMC Co., Ltd.) can be used.

[0011] Component (A) is included as the main component that forms the lipid bilayer of the liposome. Furthermore, in this invention, the moisturizing effect and skin affinity inherent in phospholipids themselves can synergistically impart a higher moisturizing effect to the topical skin composition of this invention in conjunction with other active ingredients.

[0012] The content of component (A) in the present invention is not particularly limited, but from the viewpoint of liposome stability and the coexistence stability of liposomes and bicell structures, it is preferably in the range of 0.5 to 10% by mass (hereinafter simply referred to as "%") in the topical skin composition, more preferably in the range of 1.0 to 7.0%, and even more preferably in the range of 1.5 to 5%.

[0013] (Component (B): Phytosterol) Component (B), phytosterol, used in the liposomes of the present invention is a type of sterol, but it is a component found in trace amounts in plants such as soybeans and rapeseed, and is a mixture of several sterols such as β-sitosterol, campesterol, stigmasterol, and brassicasterol. Component (B) contributes to the stability of the lipid bilayer structure, and when combined with component (A), it can improve the storage stability of the liposomes. Furthermore, because it has a larger molecular weight than other sterols such as cholesterol and is a mixture of several sterols, it can impart gloss and firmness to the topical skin composition of the present invention. A commercially available product is Phytosterol QI (manufactured by Eisai Food Chemical Co., Ltd.).

[0014] The content of component (B) in the present invention is not particularly limited, but from the viewpoint of liposome stability, firmness, etc., it is preferably in the range of 0.05 to 2.0%, more preferably in the range of 0.1 to 1.5%, and even more preferably in the range of 0.1 to 1.0% in the topical skin composition.

[0015] Furthermore, in the present invention, the mass ratio (A) / (B) of component (A) to component (B) is not particularly limited, but from the viewpoint of liposome stability and the coexistence stability of liposomes and bicell structures, it is preferably in the range of 1 to 30, more preferably in the range of 2 to 10, and even more preferably in the range of 2 to 6.

[0016] (Component (C): Polyhydric alcohol with an IOB value of 2.0 to 5.0) The polyhydric alcohol of component (C) used in the liposome in the present invention has a structure having two or more hydroxyl groups in the molecule, and is not particularly limited as long as it is used in ordinary cosmetics, quasi-drugs, pharmaceuticals, etc., but its IOB value (weighted average when multiple types are used) is 2.0 to 5.0.

[0017] The IOB value in the present invention is a value determined based on the organic concept diagram (Fujita Akira, Prediction of Organic Compounds and Organic Concept Diagrams, Chemistry Field VOL.11, No.10 (1957) 719-715). More specifically, in this organic concept diagram, regarding the physicochemical properties of compounds, the degree of physical properties mainly due to Van der Waals forces is defined as "organicity", and the degree of physical properties mainly due to electrical affinity is defined as "inorganicity" and expressed as a value. The IOB value is an index indicating the balance between inorganicity and organicity, and is expressed as IOB value = inorganicity value / organicity value. It can be said that a compound with a larger value shows more hydrophilic properties and higher polarity.

[0018] Specific examples of component (C) include 1,3-butylene glycol (IOB value = 2.5), diglycerin (IOB value = 3.5), propylene glycol (IOB value = 3.3), glycerin (IOB value = 5.0), sorbitol (IOB value = 5.0), etc. From the viewpoints of liposome stability, crystal inhibition of phytosterol, etc., it is preferably one or more selected from propylene glycol, 1,3-butylene glycol, and glycerin, and more preferably a combination of 1,3-butylene glycol and glycerin.

[0019] The content of component (C) in the present invention is not particularly limited, but from the viewpoints of the stability of the liposome composition, etc., it is preferably in the range of 5 to 40% in the skin-external composition, more preferably in the range of 5 to 30%, and even more preferably in the range of 10 to 30%.

[0020] As described above, the liposomes in the present invention exist as a liposome dispersion dispersed in an aqueous solvent, and thus the dispersion contains aqueous components such as water and lower alcohols. As the water, for example, in addition to purified water, hard water, soft water, natural water, tap water, seawater, deep ocean water, electrolyzed alkaline ion water, electrolyzed acidic ion water, ionized water, cluster water, and plant-derived steam-distilled water such as lavender water, rose water, and orange flower water can be mentioned. Further, in addition to components (A) to (C), an oil agent, a surfactant, a water-soluble polymer, various beauty active ingredients, a preservative, an antibacterial agent, an antioxidant, a pH adjuster, a chelating agent, a fragrance, etc. can be appropriately contained within a range that does not damage the structure of the liposomes.

[0021] For the production of the liposome dispersion, conventional methods known to those skilled in the art can be used. Although not particularly limited, for example, components (A) to (C) are heated in advance and uniformly mixed, and an aqueous component heated with stirring is added thereto to obtain a liposome dispersion. Subsequently, high-pressure treatment may be performed. Here, regarding the obtained liposome dispersion, by performing polarization microscope observation under crossed Nicol and confirming the Maltese cross image, it is possible to confirm that a lipid bilayer membrane is formed.

[0022] The average particle diameter of the liposomes in the present invention is not particularly limited, but from the viewpoint of more preferably exerting the effects of the present invention, it is preferably 50 to 300 nm, more preferably 100 to 250 nm, and even more preferably 100 to 200 nm. The average particle diameter of the liposome composition of the present invention can be measured with a real-time nanoparticle size measuring device DelsaMax CORE (manufactured by Beckman Coulter, Inc.).

[0023] (Bicelle structure) The "bicelle structure" in this specification refers to a disk-shaped molecular structure in which the ends of a flat membrane having a lipid bilayer membrane are covered with a surfactant such as a short-chain phospholipid, and the structure is obtained in a state of a dispersion in an aqueous solvent.

[0024] (Component (D): Phospholipids) The phospholipid component (D) used in the bicell structure in the present invention is the same as component (A) used in the liposome described above. Component (D) is used mainly as a component of the bilayer structure of the bicell structure, and while the optimal component can be selected independently of component (A), it is preferable that it be the same type of phospholipid as component (A) from the viewpoint of stability as a topical skin composition. Furthermore, the moisturizing effect and skin affinity inherent in the phospholipid itself can impart a higher sense of penetration and moisturizing effect to the topical skin composition of the present invention.

[0025] The content of component (D) in the present invention is not particularly limited, but is preferably 0.001 to 5% and more preferably 0.005 to 3% in the topical skin composition. Within this range, a composition with superior long-term stability can be obtained.

[0026] (Component (E): Ceramides) The component (E) ceramides used in the bicell structure of the present invention are nonionic amphiphilic substances having one or more long-chain linear and / or branched alkyl or alkenyl groups in the molecule, and further having at least two or more hydroxyl groups and one or more amide groups (and / or amino groups), or derivatives in which a phosphatidylcholine residue or a sugar residue is bonded to the hydroxyl group of the nonionic amphiphilic substance, and may be a natural extract or a synthetic product. While generally not limited to substances usable in cosmetics, examples include natural ceramides such as sphingosine, phytosphingosine, and their long-chain fatty acid amides, such as ceramide 1, ceramide 2, ceramide 3, ceramide 3B, ceramide 4, ceramide 5, ceramide 6, ceramide 6I, and ceramide 6II; sphingophospholipids such as sphingomyelin and phytosphingomyelin, which are phospholipid derivatives of sphingosine and phytosphingosine; and sphingoglycolipids and phytosphingoglycolipids such as cerebrosides and gangliosides, which are glycosides of these substances. One or more of these can be used in combination. Among these, natural ceramides are preferred from the viewpoint of vesicle structure stability, and ceramide 2 and ceramide 3 are particularly preferred. Examples of commercially available natural ceramides include Ceramide I, Ceramide III, Ceramide VI (all manufactured by EVONIC), Ceramide TIC-001 (manufactured by Takasago International Corporation), CERAMIDE 2 (manufactured by Croda Japan), CERAMIDE 3 (manufactured by Cosmo Farm), and Ceracare AC45 (manufactured by NFC Corporation). Component (E), together with component (D), can contribute to the stability of the bicell structure as a component that mainly constitutes the plate portion of the bicell structure.

[0027] The content of component (E) in the present invention is not particularly limited, but is preferably 0.003 to 3% and more preferably 0.005 to 2% in the topical skin composition. Within this range, a composition with superior long-term stability can be obtained.

[0028] (Component (F): At least one surfactant selected from the group consisting of polyoxyethylene sterol ether, polyoxyethylene stanol ether, and polyglycerol fatty acid esters, which are esters of polyglycerol with an average addition number of 5 to 20 and fatty acids having 10 to 22 carbon atoms.) Component (F) used in the bicell structure in the present invention is a component that mainly constitutes the ends of the bicell structure and can contribute to the stability of the bicell structure. It is at least one surfactant selected from the group consisting of a structure in which a polyoxyethylene chain is attached to a sterol or stanol, and a structure in which a fatty acid having 10 to 22 carbon atoms is esterified to a polyglycerol chain with an average number of added moles of 5 to 20.

[0029] As a surfactant with a structure in which a polyoxyethylene chain is attached to a sterol or stanol, the average number of moles of ethylene oxide corresponding to the hydrophilic part is not particularly limited, but is preferably 10 to 30, and more preferably 20 to 30. Furthermore, phytosterols are preferred as the hydrophobic part. Specifically, POE(30) phytosteryl ether is even more preferred from the viewpoint of the formation rate of bicelle structures and stability over time, and a commercially available product of this is NIKKOL BPS-30 (manufactured by Nikko Chemicals Co., Ltd.).

[0030] As a surfactant having a structure in which a fatty acid with 10 to 22 carbon atoms is esterified to a polyglycerin chain with an average number of added moles of 5 to 20, the average number of added moles of glycerin corresponding to the hydrophilic part is 5 to 20, more preferably 10 to 20. The fatty acid as the hydrophobic part may be linear or branched, and may be saturated or unsaturated, but its carbon number is 10 to 22, more preferably 12 to 18. Specifically, examples include polyglyceryl-6 laurate, polyglyceryl-10 stearate, and polyglyceryl-10 oleate. From the viewpoint of the formation rate of bicelle structures and stability over time, polyglyceryl-10 oleate is even more preferred, and a commercially available example is NIKKOL DECAGLYN 1-OV (manufactured by Nikko Chemicals Co., Ltd.).

[0031] The content of component (F) in the present invention is not particularly limited, but is preferably 0.001 to 3% and more preferably 0.005 to 2% in the topical skin composition. Within this range, a composition with superior stability over time and superior penetration can be obtained.

[0032] In the bicell structure of the present invention, the mass ratio (D) / (F) of component (D) to component (F) is 0.2 to 1.6. If the mass ratio (D) / (F) is less than 0.2 or greater than 1.6, the bicell structure formation rate may not be good. Also, the mass ratio (E) / {(D)+(F)} of component (E) to the sum of component (D) and component (F) is 0.1 to 0.8. If the mass ratio (E) / {(D)+(F)} is less than 0.1 or greater than 0.8, the bicell structure formation rate may not be good, or the stability over time may not be good. From the viewpoint of stability over time, a mass ratio (E) / {(D)+(F)} of 0.1 to 0.5 is more preferable. Within this range, when the bicell structure is coexisted with liposomes in the topical skin composition of the present invention, the shape retention of the bicell structure can be further improved, which is preferable.

[0033] (Component (G): At least one dihydric alcohol selected from the group consisting of propylene glycol, dipropylene glycol, and 1,3-butylene glycol) Component (G) used in the bicell structure in the present invention is a solvent for preparing a bicell structure with superior long-term stability, and can be used as needed, either alone or in combination of two or more, but from the viewpoint of solubility of ceramides, dipropylene glycol is preferred.

[0034] The content of component (G) in the present invention is not particularly limited, but is preferably 0.01 to 20% and more preferably 0.03 to 10% in the topical skin composition. This range is preferred because it provides particularly excellent long-term stability for compositions containing the BiCell structure.

[0035] As described above, the BiCell structure in the present invention exists as a BiCell structure dispersion in an aqueous solvent, and therefore the dispersion contains aqueous components such as water and lower alcohols. As for the water, for example, in addition to purified water, hard water, soft water, natural water, tap water, seawater, deep-sea water, electrolyzed alkaline ionized water, electrolyzed acidic ionized water, ionized water, cluster water, or plant-derived steam distilled water such as lavender water, rose water, and orange blossom water can be used. Furthermore, within a range that does not hinder the formation of the BiCell structure, optional components other than components (D) to (G) that are normally incorporated into cosmetics, specifically preservatives, antibacterial agents, fragrances, antioxidants, pH adjusters, chelating agents, and cosmetic active ingredients can be included.

[0036] The bicell structure in the present invention is not particularly limited and can be manufactured by various methods for manufacturing ordinary cosmetics, etc. However, a manufacturing method in which components (D), (E), and (F) are dispersed in component (G), and then mixed and stirred with an aqueous solvent is preferred because it is suitable for mass production due to its high yield and the fact that it does not require special equipment (e.g., a high-pressure emulsifier). Specifically, components (D), (E), and (F) are dispersed in component (G) heated to a temperature of about 80°C, the solution is added to an aqueous solvent heated to a temperature of about 80°C and mixed and stirred, then gradually cooled to room temperature, and optional components are added as needed and mixed and stirred. The stirring method during preparation and cooling is also not particularly limited.

[0037] As described above, the bicell composition of the present invention is obtained, and the presence of a disk-like image and particle size of the bicell structure can be confirmed by transmission electron microscopy. The average particle size of the bicell structure in the present invention is preferably 10 to 80 nm, more preferably 15 to 70 nm, for the major axis, and preferably 1 to 10 nm, more preferably 3 to 8 nm, for the minor axis.

[0038] (Skin external composition) The topical skin composition of the present invention is obtained by appropriately mixing the liposome dispersion and the Bicell structure dispersion. From the viewpoint of long-term stability and firmness, it is preferable that the total amount of (A) and (B) in the liposomes and the total amount of components (D) to (F) in the Bicell structure are in a mass ratio of 200:1 to 1:1 and 180:1 to 2:1.

[0039] The skin topical composition of the present invention can be made even more stable by further including an anionic polymer as component (H). Component (H) used in the skin topical composition of the present invention is a polymer having anionic functional groups in its molecule, and is not particularly limited as long as it is commonly used in cosmetics. Specifically, examples include water-soluble polymers such as alginic acid, hyaluronic acid, gum arabic, carrageenan, chondroitin sulfate, gelatin, carboxymethylcellulose, carboxyvinyl polymer, alkyl-modified carboxyvinyl polymer, polyacrylic acid, and their derivatives, and one or more of these can be used. These are not particularly limited by their origin, whether natural or synthetic. Among these, carboxyvinyl polymer and / or alkyl-modified carboxyvinyl polymer are preferred from the viewpoint of long-term stability. Commercially available carboxyvinyl polymers include CARBOPOL940, CARBOPOL941, CARBOPOL980, CARBOPOL934 (all manufactured by LUBRIZOL ADVANCED MATERIALS), and AQUPEC HV-501 (manufactured by Sumitomo Seika Co., Ltd.). Commercially available alkyl-modified carboxyvinyl polymers include CARBOPOL1342, CARBOPOL1382 (both manufactured by LUBRIZOL ADVANCED MATERIALS), Pemulene TR-1, and Pemulene TR-2 (both manufactured by NOVEON).

[0040] From the viewpoint of long-term stability, the content of component (H) in the present invention is preferably 0.01 to 0.8% in the topical skin composition.

[0041] Furthermore, the topical skin composition of the present invention may use ingredients commonly found in cosmetics and topical skin preparations, as long as they do not interfere with the effects of the present invention. Specific examples of such ingredients include alcohols, powders, film-forming agents, surfactants other than essential components, oil-soluble gelling agents, organically modified clay minerals, resins, UV absorbers, preservatives, antibacterial agents, fragrances, antioxidants, pH adjusters, chelating agents, and skin-active ingredients.

[0042] The skin external composition of the present invention obtained as described above can be used as a cosmetic, quasi-drug, or skin external preparation. Examples include cosmetics such as lotions, emulsions, creams, eye creams, serums, massage products, packs, hand creams, body lotions, body creams, makeup bases, and sunscreens; and skin external preparations such as topical liquids, topical gels, creams, ointments, liniments, lotions, poultices, plasters, sprays, and aerosols. Methods of use include application by hand or finger, and application by impregnating cotton or nonwoven fabric. [Examples]

[0043] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to the following examples. (Production Examples 1 to 4, Production Comparative Examples 1 to 2: Bicelle structure dispersion liquid) A bicell structure dispersion with the composition shown in Table 1 was prepared according to the manufacturing method described below. Furthermore, the formation rate of bicelle structures and the temporal stability of the dispersion were confirmed and evaluated using the following evaluation method.

[0044] [Table 1]

[0045] (Manufacturing method) 1: Heat ingredients (1) to (5) to 80°C and dissolve. 2: Heat ingredient (6) to 80°C. Add 1 to a 3:2 ratio and mix and stir using a Despa mixer. The 4:3 mixture was cooled to room temperature, components (7) to (9) were added, and the mixture was stirred to obtain a Bicell structure dispersion.

[0046] (Evaluation Method 1) Disk images specific to bicell structures were observed using a transmission electron microscope, and the ratio of (number of disk images / total number of particle images) within the observation field (350 nm × 350 nm) of an arbitrarily selected electron microscope was calculated and judged according to the following criteria. (Evaluation result): (Judgment) (Number of disk images / Total number of particle images) is 0.8 or higher: ◎ (Number of disk images / Total number of particle images) is 0.5 or greater and less than 0.8: ○

[0047] (Evaluation Method 2) Each sample was filled into a standard No. 5 bottle and stored for two weeks in a constant temperature bath at 50°C and a constant temperature bath at 25°C. The samples were then compared, and the transparency and presence or absence of precipitates were visually observed. The sample stored at 25°C was used as the standard for evaluation. (Evaluation result): (Judgment) No change in appearance: ◎ A slight cloudiness is visible on the surface, but no precipitates are observed: ○

[0048] Examples 1-13 and Comparative Examples 1-4: Topical skin preparations A topical skin preparation with the composition shown in Table 2 was prepared according to the manufacturing method described below. Each sample obtained was evaluated for "coexistence stability of liposomes and vesicle structures" and "firmness" using the evaluation method and criteria described below. The results are shown in Table 2.

[0049] [Table 2]

[0050] (Manufacturing method) A: Heat ingredients (1) to (5) to 80°C and mix them uniformly. B: Heat component (6) to 80°C. C: Gradually add B to A and mix and stir using a Despa mixer. After cooling D:C to room temperature, it is subjected to high-pressure treatment in a microfluidizer to obtain a liposome dispersion. E: Dissolve component (8) uniformly in component (9). Components (7), (10) to (15), and E were added to F:D and mixed and stirred in a Despa mixer to obtain a topical skin preparation.

[0051] (Evaluation method 1: Coexistence stability of liposomes and bicell structures) The coexistence stability of liposomes and bicell structures was evaluated by replacing it with the retention of liposome shape. This is because poor coexistence stability between liposomes and bicell structures is reflected in changes in the average particle size of liposomes due to liposome disintegration or coalescence. Each sample from Examples 1-13 and Comparative Examples 1-4 was filled into a No. 5 standard bottle and stored at a constant temperature of 50°C for one month. The average particle size of liposomes in each sample was then measured. The rate of change in average particle size was then calculated using the average particle size of liposomes measured before mixing with the bicell structure as a reference. The average particle size was measured by filling each sample into a plastic cuvette UVette 220-1600nm (Eppendorf) and measuring it using a real-time nanoparticle size analyzer DelsaMax CORE (Beckman Coulter, Inc.). [Judgment criteria] (Evaluation result): (Judgment) The rate of change in average particle size is less than ±15%: ◎ The rate of change in average particle size is ±15% or more and less than ±20%: ○ The rate of change in average particle size is ±20% or more and less than ±35%: △ The rate of change in average particle size is ±35% or more: ×

[0052] (Evaluation method 2: firmness) A panel of 25 cosmetic product evaluators aged 35-50 took approximately 1g of each sample from Examples 1-13 and Comparative Examples 1-4 twice a day, morning and evening, after washing their faces. They applied one sample to one half of their face and the other sample to the other half, conducting a simultaneous use test of both samples. After two weeks of continuous use, they evaluated the firmness of their skin on a 5-point scale using the evaluation criteria below. Furthermore, the average score of each sample from the panel was determined using the judgment criteria below. [Evaluation Criteria] (Evaluation result): (Score) Very good: 5 points Good: 4 points Normal: 3 points Slightly poor: 2 points Defective: 1 point [Judgment criteria] (Judgment): (Average score) ◎: 4.5 or higher ○: 3.5 or higher and less than 4.5 △: 1.5 or higher, but less than 3.5 ×: Less than 1.5

[0053] (result) As is clear from Table 2, all of the topical skin preparations in Examples 1 to 13 exhibited excellent coexistence stability between liposomes and bicell structures, and were also found to provide excellent firmness after prolonged use. On the other hand, Comparative Example 1, which had a high liposome content, did not achieve the penetration effect of the BiCell structure, and the feeling of firmness after continuous use was not entirely satisfactory. In Comparative Example 2, which also had a high BiCell structure content, although a feeling of firmness was obtained due to the penetration effect of the BiCell structure, the amount of BiCell components was too high relative to the liposomes, causing the liposome structure to collapse. This resulted in poor coexistence stability between liposomes and BiCell structures, leading to subsequent changes in appearance. Comparative Examples 3 and 4, which were prepared using BiCell structures with deviations from the (D) / (F) ratio and (E) / ((D)+(F)) ratio, did not achieve satisfactory coexistence stability between liposomes and BiCell structures.

[0054] <Example 14: Lotion> (Prescription) (%) (1) Phospholipids Note 1 2.0 (2) Phytosterols Note 3 0.3 (3) Glycerin 5.0 (4) 1,3-Butylene glycol 15.0 (5) Diglycerin 5.0 (6) Purified water 50.0 (7) Bicell structure dispersion of Manufacturing Example 1 1.0 (8) Tocopherol 0.05 (9) Carbomer 0.05 (10) Sodium hydroxide 0.02 (11) Phenoxyethanol 0.5 (12) Ethanol 1.0 (13) Purified water remaining amount

[0055] (Manufacturing method) A: Heat ingredients (1) to (5) to 80°C and mix them uniformly. B: Heat component (6) to 80°C. C: Gradually add B to A and disperse using a dispersive mixer. D:C is cooled to room temperature and then subjected to high-pressure processing in a microfluidizer. E:D was mixed with ingredients (7) to (13) to obtain a lotion. The resulting cloudy lotion exhibited excellent temporal stability of liposomes and bicell structures, as well as superior usability, including firmness. The mass ratio of the total amount of components (A) and (B) in the liposomes to the total amount of components (D) to (F) in the bicell structures was 23:1.

[0056] <Example 15: Serum> (Prescription) (%) (1) Phospholipids Note 1 3.0 (2) Phytosterols Note 3 0.5 (3) Ceramide 2 0.01 (4) Glycerin 5.0 (5) 1,3-Butylene glycol 7.5 (6) Purified water 50.0 (7) Bicell structure dispersion of manufacturing example 4 15.0 (8) Acrylates / Acrylic Acid (C10-30) Crosspolymer 0.3 (9) Carrageenan Note 4 0.1 (10) Tocopherol 0.02 (11) Succinic acid 0.01 (12) Disodium succinate 0.05 (13) Sodium hydroxide 0.1 (14) Ethanol 4.0 (15) Nylon-12 2.0 (16) Purified water remaining amount Note 4: Carrageenan J (manufactured by Asahi Chemical Industry Co., Ltd.)

[0057] (Manufacturing method) A: Heat ingredients (1) to (5) to 80°C and mix them uniformly. B: Heat component (6) to 80°C. C: Gradually add B to A and disperse using a dispersive mixer. D:C is cooled to room temperature and then subjected to high-pressure processing in a microfluidizer. E: Mix ingredients (7) to (16) uniformly. A serum was obtained by adding D to F:E and mixing them uniformly. (result) The resulting serum exhibited excellent stability over time for both liposomes and bicell structures, as well as superior usability, including firmness. The mass ratio of the total amount of components (A) and (B) in the liposomes to the total amount of components (D) to (F) in the bicell structures was 2:1.

[0058] <Example 16: Oil-in-water emulsion> (Prescription) (%) (1) Phospholipids Note 1 3.0 (2) Phytosterols Note 3 0.5 (4) Glycerin 10.0 (5) 1,3-Butylene glycol 15.0 (6) Dipropylglycol 5.0 (7) Purified water 50.0 (8) Hydrogenated polydecene Note 5 0.5 (9) Macadamia nut fatty acid phytosteryl Note 6 0.5 (10) Tocopherol 0.01 (11) Cetyl 2-ethylhexanoate 1.0 (12) Polyoxyethylene hydrogenated (60) castor oil 0.8 (13) Cetostearyl alcohol 0.15 (14) Bicell structure dispersion of manufacturing example 3.0 (15) Acrylates / C10-30 Acrylic Acid Crosspolymer 0.2 (16) Carbomer Na Note 7 0.2 (17) Sodium hydroxide 0.06 (18)Fragrance 0.1 (19) Ethanol 2.0 (20) Silica 0.005 (21) EDTA-2Na 0.05 (22) Phenoxyethanol 0.5 (23) Purified water remaining amount Note 5: SILKFLO 364 (manufactured by LIPO CHEMICALS INC.) Note 6: PLANDOOL-MAS (manufactured by Nippon Seika Co., Ltd.) Note 7: AQUPEC MG N40R (manufactured by Sumitomo Seika Co., Ltd.)

[0059] (Manufacturing method) A: Heat ingredients (1) to (6) to 80°C and mix them uniformly. B: Heat component (7) to 80°C. C: Gradually add B to A and disperse using a dispersive mixer. D:C is cooled to room temperature and then subjected to high-pressure processing in a microfluidizer. E: Heat ingredients (8) to (13) to 70°C and mix uniformly. F: Heat a portion of components (21), (22), and (23) to 70°C and mix them uniformly. Add F to G:E and mix with a Despa mixer until emulsified. After cooling H:G to room temperature, components (14) to (20) and the remainder of (23) were added and mixed uniformly to obtain an oil-in-water emulsion. (result) The resulting oil-in-water emulsion exhibited excellent stability over time for both liposomes and bicell structures, as well as superior usability, including firmness. The mass ratio of the total amount of components (A) and (B) in the liposomes to the total amount of components (D) to (F) in the bicell structures was 12:1.

[0060] <Example 17: Oil-in-water cream> (Prescription) (%) (1) Phospholipids Note 1 3.0 (2) Phytosterols Note 3 0.5 (3) Glycerin 12.0 (4) 1,3-Butylene glycol 10.0 (5) Purified water 40.0 (6) Hydrogenated isobutene Note 8 3.0 (7) Lauroyl glutamate di(octyldodecyl / phytosteryl / Behenyl) Note 9 0.4 (8) Tocopherol 0.02 (9) Triethylhexanoin 2.0 (10) Lauryl polyglyceryl-3 polydimethylsiloxyethyl dimethicone Note 10 0.1 (11) Cetostearyl alcohol 0.8 (12) Bicell structure dispersion of manufacturing example 4 0.3 (13) Acrylates / Acrylic Acid (C10-30) Crosspolymer 0.2 (15) Carbomer 0.2 (16) PVP 0.15 (17) Sodium hydroxide 0.15 (18) Sodium monohydrogen phosphate 0.03 (19) Sodium dihydrogen phosphate 0.3 (20)Fragrance 0.2 (21) Ethanol 3.0 (22) EDTA-2Na 0.05 (23) Phenoxyethanol 0.5 (24) Purified water remaining amount Note 8: Pearlream 18 (manufactured by NOF Corporation) Note 9: Eldew PS-306 (manufactured by Ajinomoto Co., Inc.) Note 10: KF-6105 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0061] (Manufacturing method) A: Heat ingredients (1) to (4) to 80°C and mix them uniformly. B: Heat component (5) to 80°C. C: Gradually add B to A and disperse using a dispersive mixer. D:C is cooled to room temperature and then subjected to high-pressure processing in a microfluidizer. E: Heat ingredients (8) to (11) to 70°C and mix uniformly. F: Heat a portion of components (22), (23), and (24) to 70°C and mix them uniformly. Add F to G:E and mix with a Despa mixer until emulsified. After cooling H:G to room temperature, the remaining components (12) to (21) and (24) were added and mixed uniformly to obtain an oil-in-water cream. (result) The resulting oil-in-water cream exhibited excellent stability over time for both liposomes and bicell structures, as well as superior usability, including firmness. The mass ratio of the total amount of components (A) and (B) in the liposomes to the total amount of components (D) to (F) in the bicell structures was 117:1.

Claims

1. A topical skin composition containing liposomes and a bicell structure, The liposome is a liposome containing component (A) phospholipid, component (B) phytosterol, and component (C) polyhydric alcohol with an IOB value of 2.0 to 5.

0. The bicell structure contains at least one surfactant selected from the group consisting of component (D) phospholipids, component (E) ceramides, component (F) polyoxyethylene sterol ethers, polyoxyethylene stanol ethers, and polyglycerin fatty acid esters which are esters of polyglycerin with an average addition number of 5 to 20 and fatty acids having 10 to 22 carbon atoms, and component (G) at least one dihydric alcohol selected from the group consisting of propylene glycol, dipropylene glycol, and 1,3-butylene glycol, wherein the mass ratio of component (D) to component (F) (D) / (F) is 0.2 to 1.6, and the mass ratio of component (E) to the sum of component (D) and component (F) (E) / {(D)+(F)} is 0.1 to 0.

8. Furthermore, the topical skin composition is such that the total amount of components (A) and (B) in the liposome and the total amount of components (D) to (F) of the bicell structure are in a mass ratio of 200:1 to 1:

1.

2. The topical skin composition according to claim 1, further comprising component (H) an anionic polymer.

3. The topical skin composition according to claim 2, wherein the component (H) contains one or more selected from carboxyvinyl polymers and / or alkyl-modified carboxyvinyl polymers.

Images