External preparation for skin

Abstract

To provide an external preparation for skin that has a structure of emulsion including a specific aliphatic alcohol and a specific surfactant, necessary for the barrier performance of its preparation, and also excels in the strength and barrier performance of preparation coating.SOLUTION: An external preparation for skin contains following components (A)-(E): (A) at least one selected from C14-20 aliphatic alcohols, (B) at least one selected from polyhydric alcohol fatty acid ester-based nonionic surfactants, (C) at least one selected from ionic surfactants, (D) water and (E) fibers with an average fiber diameter of 0.001-7 μm inclusive and an average fiber length of 0.01- 1000 μm inclusive in an amount of 0.01-10 mass%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an external preparation for skin.

Background Art

[0002] Conventionally, many proposals have been made for external preparations for skin aimed at improving the skin barrier function. For example, skin cosmetics containing an intercellular lipid component, a moisturizing component, and a phospholipid (Patent Document 1), an external preparation for skin containing N-acylglutamic acid diester and pyrrolidone carboxylic acid-modified dimethylpolysiloxane (Patent Document 2), an external preparation composition containing a specific diamide derivative and a keratinocyte intercellular lipid component (Patent Document 3), and the like can be mentioned.

[0003] On the other hand, external preparations for skin containing fibers are also known for the purpose of improving makeup retention and giving a smooth feeling to the skin (Patent Documents 4 to 6).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, although the topical skin preparations described in Patent Documents 1 to 3 improve the skin barrier function, the effect of suppressing substance permeation was not sufficient. Further, the topical skin preparations described in Patent Documents 4 to 6 could not be said to be fully satisfactory in terms of emulsion stability and the feeling of use during application. Furthermore, generally, after a topical skin preparation is applied to the skin, the durability of the film on the skin against physical stimuli such as clothing rubbing is not sufficient, and for this reason, there is a problem that the performance of the preparation deteriorates. None of the topical skin preparations of Patent Documents 1 to 6 could reduce such problems.

[0006] Therefore, the present invention relates to a topical skin preparation in which fine fibers are blended in a structure of an emulsion containing a specific aliphatic alcohol and a specific surfactant necessary for the barrier performance (substance permeation suppression and suppression of water evaporation from inside the skin) of the preparation, whereby the barrier performance is further improved and the strength of the preparation film is excellent.

Means for Solving the Problems

[0007] The present inventors have found that the above problems can be solved by incorporating specific fibers into a base formulation containing a specific higher alcohol, a specific nonionic surfactant, an ionic surfactant, and water, and have completed the present invention.

[0008] The present invention provides a topical skin preparation containing the following components (A) to (E). (A) One or more selected from aliphatic alcohols having 14 to 20 carbon atoms (B) One or more selected from polyhydric alcohol fatty acid ester type nonionic surfactants (C) One or more selected from ionic surfactants (D) Water (E) Fibers having an average fiber diameter of 0.001 μm or more and 7 μm or less and an average fiber length of 0.01 μm or more and 1000 μm or less, 0.01% by mass or more and 10% by mass or less

Effects of the Invention

[0009] The external preparation for skin of the present invention has further improved barrier performance of the preparation due to the formation of a structure by the emulsion, and is excellent in the strength of the preparation film.

Brief Description of Drawings

[0010]

Figure 1

Modes for Carrying Out the Invention

[0011] In the external preparation for skin of the present invention, specific fibers coexist with the structure formed by the emulsion, so that the emulsified state is stabilized, that is, the structure is maintained. Furthermore, smoothness and good elongation during application can be ensured, so that it is excellent in forming a uniform film. Furthermore, since the fibers coexist with the structure in the preparation film, the strength of the preparation film after drying is excellent, and an improvement in the barrier performance by the preparation film is expected. Here, examples of the barrier performance include suppression of permeation of substances such as allergens and suppression of transpiration of moisture from inside the skin.

[0012] The external preparation for skin of the present invention contains the following components (A) to (E). The structure of the emulsion is formed by components (A), (B), (C) and (D). And when component (E) further coexists therewith, the strength of the preparation film after drying is remarkably improved, and the barrier performance is also improved. Here, the film means a film-like structure containing the structure of the emulsion formed by applying the external preparation for skin of the present invention on the skin, which is different from a mere liquid film or an accumulation of powder, and component (E) coexists with the structure of this emulsion in the film.

[0013] 〔Component (A): aliphatic alcohol having 14 to 20 carbon atoms〕 As the aliphatic alcohol having 14 or more and 20 or less carbon atoms of component (A), a linear aliphatic alcohol and / or a saturated aliphatic alcohol is preferable, and a linear saturated aliphatic alcohol is more preferable. Specific examples of component (A) include myristyl alcohol, cetyl alcohol, stearyl alcohol, and arachidyl alcohol.

[0014] As the component (A), any one of them can be used alone or in combination of two or more. From the viewpoint of storage stability in an emulsified state, it is preferable to use a combination of two or more compounds having different carbon numbers. Further, from the same viewpoint, among the component (A), the mass ratio (a1) / (a2) of the short-chain (carbon number 14 or more and less than 18) aliphatic alcohol to the long-chain (carbon number 18 or more and 20 or less) aliphatic alcohol is preferably 0.1 or more, more preferably 0.6 or more, still more preferably 1.0 or more, and is preferably 7.0 or less, more preferably 5.0 or less, still more preferably 3.0 or less, and even more preferably 2.5 or less.

[0015] The content of the component (A) in the external preparation for skin of the present invention is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, still more preferably 0.8% by mass or more from the viewpoint of suppressing substance permeation, and is preferably 4.0% by mass or less, more preferably 3.0% by mass or less, still more preferably 2.5% by mass or less, and even more preferably 2.0% by mass or less from the viewpoint of storage stability in an emulsified state.

[0016] [Component (B): Polyhydric Alcohol Fatty Acid Ester Type Nonionic Surfactant] Examples of component (B) include sucrose fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan monofatty acids, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene hydrogenated castor oil, and the like. Component (B) can be used alone or in combination of two or more thereof, and it is preferable to use two or more thereof in combination. As a combination of two or more polyhydric alcohol fatty acid esters, from the viewpoint of forming a dry film having an emulsion structure excellent in barrier performance, (b1) one or more polyhydric alcohol fatty acid esters having an HLB of 3 or more and 7 or less, more preferably 4 or more and 6 or less, and (b2) an HLB of 11 or more and 16, more preferably 13 or more and 15 or less. A combination with one or more polyhydric alcohol fatty acid esters is preferred. Also, from the same viewpoint, the mass ratio (b1) / (b2) of these is preferably 0.25 or more, more preferably 0.4 or more, still more preferably 0.6 or more, and is preferably 4.0 or less, more preferably 2.0 or less, still more preferably 1.5 or less.

[0017] From the viewpoint of storage stability in the emulsified state, the content of component (B) in the external preparation for skin of the present invention is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, still more preferably 1.5% by mass or more, and from the viewpoint of smoothness during application, it is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, still more preferably 3.0% by mass or less, still more preferably 2.0% by mass or less.

[0018] From the viewpoint of suppressing substance permeation, the mass ratio (A) / (B) of component (A) and component (B) in the external preparation for skin of the present invention is preferably 0.3 or more, more preferably 0.35 or more, still more preferably 0.4 or more, and from the viewpoint of good elongation during application, it is preferably 3.0 or less, more preferably 2.0 or less, still more preferably 1.5 or less.

[0019] [Component (C): Ionic surfactant] The ionic surfactant of component (C) is a component that imparts a substance permeation inhibitory function to a structure of an emulsion containing specific aliphatic alcohols and surfactants formed on the skin, preferably a dry film having a lamellar structure. Examples of component (C) include one or more selected from anionic surfactants, cationic surfactants, and amphoteric surfactants, and preferably include one or more selected from anionic surfactants and amphoteric surfactants.

[0020] Examples of anionic surfactants include, for example, N-acyl amino acids, N-acyl taurines or their salts; fatty acids having 12 to 22 carbon atoms such as sodium laurate, potassium palmitate, arginine stearate or their salts; alkyl sulfate esters having 12 to 22 carbon atoms such as sodium lauryl sulfate, potassium lauryl sulfate or their salts; alkyl ether sulfate esters having 12 to 22 carbon atoms such as triethanolamine polyoxyethylene lauryl sulfate or their salts; N-acyl sarcosines having 12 to 22 carbon atoms such as sodium lauroyl sarcosinate or their salts; alkyl phosphates having 12 to 22 carbon atoms such as sodium monostearyl phosphate or their salts; polyoxyethylene alkyl ether phosphates having 12 to 22 carbon atoms such as sodium polyoxyethylene cetyl ether phosphate, sodium polyoxyethylene oleyl ether phosphate, sodium polyoxyethylene stearyl ether phosphate or their salts; dialkyl sulfosuccinates having 12 to 24 carbon atoms such as sodium di-2-ethylhexyl sulfosuccinate or their salts.

[0021] As an anionic surfactant, N-acyl amino acid, N-acyl taurine or a salt thereof is preferable. From the viewpoint of storage stability in an emulsified state, the acyl group of N-acyl amino acid and N-acyl taurine is preferably derived from a saturated or unsaturated linear or branched fatty acid or a mixed fatty acid thereof, more preferably derived from a linear fatty acid or a mixed fatty acid of linear fatty acids, the number of carbon atoms thereof is preferably 6 or more, more preferably 10 or more, still more preferably 12 or more, and also preferably 22 or less, more preferably 20 or less, still more preferably 18 or less. As such an acyl group, from the viewpoint of reducing skin irritation, one or more selected from a caproyl group, a lauroyl group, a myristoyl group, a palmitoyl group, a stearoyl group, and a cocooyl group are preferable, and an acyl group derived from animal or vegetable oil such as palm oil may also be used.

[0022] As the amino acid moiety of N-acyl amino acid, glutamic acid and aspartic acid are preferable from the viewpoint of storage stability of the drug. Here, glutamic acid may be any of D-form, L-form or a mixture of D-form and L-form, and L-form is preferable. As such N-acyl amino acid, specifically, from the viewpoint of storage stability in an emulsified state, one or more selected from N-stearoyl glutamic acid, N-lauroyl glutamic acid, N-myristoyl glutamic acid, N-cocooyl glutamic acid, N-palm fatty acid glutamic acid and N-lauroyl aspartic acid are preferable, and one or more selected from N-stearoyl glutamic acid and N-palm fatty acid glutamic acid are more preferable.

[0023] As N-acyl taurine, one or more selected from methyl taurine coconut oil fatty acid, N-caproyl methyl taurine, N-lauroyl methyl taurine, N-myristoyl methyl taurine, N-palmitoyl methyl taurine, N-stearoyl methyl taurine, and N-oleoyl methyl taurine are preferable from the viewpoint of storage stability in an emulsified state, and N-stearoyl methyl taurine is more preferable.

[0024] Examples of the salts of these N-acyl amino acids and N-acyl taurine include alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as calcium salt and magnesium salt; other metal salts such as aluminum salt and zinc salt; ammonium salt; organic amine salts such as monoethanolamine salt, diethanolamine salt, and triethanolamine salt; basic amino acid salts such as arginine salt, lysine salt, histidine salt, and ornithine salt. These may be used alone or in combination of two or more. Among them, as the salts of N-acyl amino acid salts and N-acyl taurine, from the viewpoint of storage stability in an emulsified state, alkali metal salts are preferred, and sodium salts are more preferred.

[0025] Examples of the cationic surfactant include didecyldimethylammonium chloride, distearyldimethylammonium chloride, dialkyldimethylammonium chloride, dibehenyldimethylammonium chloride, N-coconut fatty acid acyl-L-arginine ethyl salt, sphingosine salt, and the like.

[0026] Examples of the amphoteric surfactant include phospholipids. Examples of the phospholipids include glycerophospholipids such as lecithin, hydrogenated lecithin, hydroxylated lecithin, phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, phosphatidylinositol, phosphatidylglycerol, and cardiolipin; and sphingophospholipids such as sphingomyelin, cerebroside, and ganglioside. Among them, hydrogenated lecithin is preferred, and soybean hydrogenated lecithin is more preferred.

[0027] As component (C), among the above specific compounds, from the viewpoint of storage stability in an emulsified state, those classified into one or more selected from N-acyl amino acids, N-acyl taurine and their salts, and phospholipids are preferred, and those classified into sodium N-acylglutamate, sodium N-acylmethyltaurine and hydrogenated lecithin are more preferred.

[0028] Component (C) can be used alone or in combination of two or more thereof. From the viewpoints of suppressing substance permeation and improving the storage stability of the emulsified state, the content of component (C) in the external preparation for skin of the present invention is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.3% by mass or more. Also, from the viewpoints of smoothness during application and suppressing substance permeation, it is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, still more preferably 0.6% by mass or less, and still more preferably 0.5% by mass or less.

[0029] The mass ratio (A) / (C) of component (A) and component (C) in the external preparation for skin of the present invention is preferably 1.0 or more, more preferably 1.5 or more, still more preferably 2.0 or more from the viewpoint of suppressing substance permeation. Also, from the viewpoint of the storage stability of the emulsified state, it is preferably 15 or less, more preferably 10 or less, still more preferably 7.0 or less.

[0030] 〔Component (D): Water〕 From the viewpoint of good elongation during application, the content of component (D) in the external preparation for skin of the present invention is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more. Also, from the viewpoint of suppressing substance permeation, it is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less.

[0031] 〔Component (E): Fiber〕 Component (E) is a fiber having an average fiber diameter of 0.001 μm or more and 7 μm or less and an average fiber length of 0.01 μm or more and 1000 μm or less.

[0032] When the cross-section of the fiber of component (E) is circular, the fiber diameter is the diameter, but when the cross-section is elliptical, the fiber diameter is the major axis. From the viewpoints of enhancing the obtained film strength and suppressing substance permeation, the average fiber diameter of the fiber of component (E) is 0.001 μm or more and 7 μm or less. Considering realistic compounding amounts, it is preferably 0.05 μm or more, more preferably 0.1 μm or more, still more preferably 0.2 μm or more. Also, from the viewpoints of smoothness during coating and suppressing substance permeation, it is preferably 5 μm or less, more preferably 4 μm or less, still more preferably 3 μm or less, still more preferably 2 μm or less, still more preferably 1.5 μm or less.

[0033] The fiber diameter can be measured by observing the fiber magnified 2000 to 500000 times with a scanning electron microscope (SEM) or an atomic force microscope (AFM), arbitrarily selecting 100 fibers excluding defects (e.g., fiber aggregates, fiber intersections) from the two-dimensional image, drawing a line perpendicular to the longitudinal direction of the fiber, and directly reading the fiber diameter. The arithmetic mean of these measured values is taken as the average fiber diameter. When the fiber is dispersed in the film, the composition is thinly coated on a substrate and measured by SEM observation or AFM observation. This means is common in other measurements in this specification.

[0034] From the viewpoints of enhancing the obtained film strength and suppressing substance permeation, the length of the fiber of component (E) is 0.01 μm or more and 1000 μm or less as the average fiber length. From the viewpoints of enhancing the obtained film strength and suppressing substance permeation, the average fiber length of the fiber of component (E) is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 10 μm or more, still more preferably 50 μm or more. Also, from the viewpoint of suppressing entanglement and twisting between fibers during composition coating, it is preferably 750 μm or less, more preferably 600 μm or less, still more preferably 500 μm or less, still more preferably 300 μm or less, still more preferably 250 μm or less, still more preferably 150 μm or less.

[0035] The fiber length can be measured by observing under magnification of 250 to 50,000 times according to the fiber length through SEM observation or AFM observation. Arbitrarily select 100 fibers excluding defects (for example, fiber clusters, fiber intersection parts) from the two-dimensional image, draw a line in the longitudinal direction of the fiber, and directly read the fiber length to measure. The arithmetic mean of these measured values is defined as the average fiber length.

[0036] From the viewpoints of enhancing the obtained film strength and improving the storage stability of the emulsified state, the aspect ratio (average fiber length / average fiber diameter) of the fiber of component (E) is preferably 5 or more, more preferably 10 or more, still more preferably 50 or more, still more preferably 100 or more, and from the viewpoint of increasing the contact frequency between the fiber and the film component and improving the film strength, it is still more preferably 200 or more. Also, from the viewpoint of compatibility, it is preferably 10,000 or less, more preferably 5,000 or less, still more preferably 3,000 or less, still more preferably 1,000 or less, and still more preferably 500 or less. Note that the aspect ratio of the fiber as referred to in this specification is not a value for a single fiber, but a value calculated from the average fiber diameter obtained according to the measurement method of the fiber diameter and the average fiber length obtained according to the measurement method of the fiber length.

[0037] In the present invention, the fiber of component (E) has the above-mentioned average fiber diameter and average fiber length, so that when the formed film is changed by physical stimulation, friction is generated with the film component, thereby strengthening the film strength and further improving the barrier performance.

[0038] Furthermore, the specific surface area (surface area / unit volume) of component (E) is preferably 0.5 or more, more preferably 1 or more, still more preferably 2 or more, still more preferably 4 or more from the viewpoint that the friction increases as the contact area between the fiber and the film component increases, and from the viewpoint of improving the storage stability of the emulsified state, it is preferably 1500 or less, more preferably 1000 or less, still more preferably 500 or less, still more preferably 100 or less, still more preferably 50 or less, and still more preferably 30 or less.

[0039] In 1 mL of a 0.01% by mass aqueous solution of the external preparation for skin of the present invention, the number of fibers of component (E) is preferably 1.0×10 5 or more, more preferably 2.0×10 5 or more, still more preferably 5.0×10 5 or more, still more preferably 1.0×10 6 or more, from the viewpoint that as the number of fibers increases, the friction increases as the contact frequency between the film-forming component and the fibers increases. Also, from the viewpoint of improving the storage stability of the emulsified state, it is preferably 1.0×10 15 or less, more preferably 1.0×10 14 or less, still more preferably 1.0×10 8 or less.

[0040] Furthermore, the fibers of component (E) may form a network in the formed film. In this specification, a network means a state in which fibers dispersed in the film have two or more intersections with each other, so that there are gaps between the fibers, and a state in which components other than component (E) in the external preparation for skin can be held in these gaps. Whether or not the fibers form a network in the film is confirmed by SEM or AFM.

[0041] The fibers of component (E) can be produced by a method including a step of short-fibrillating fibers obtained by various known spinning techniques using a fiber-forming polymer. Here, the fiber-forming polymer is usually a chain polymer that is thermoplastic or soluble in a solvent, preferably a thermoplastic resin, and a thermoplastic resin having a weight average molecular weight of 1.0×10 4 g / mol to 2.0×10 5 g / mol is more preferable.

[0042] The weight average molecular weight of the thermoplastic resin can be measured according to the following conditions as the weight average molecular weight in terms of polystyrene when measuring the weight average molecular weight of the biodegradable polyester using, for example, gel permeation chromatography. As the polystyrene standard samples, polystyrene samples with known weight average molecular weights and different weight average molecular weights (for example, monodisperse polystyrene manufactured by Tosoh Corporation (model numbers: F450, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, A1000, A500, and A300)) are used to prepare a molecular weight calibration curve in advance, and it can be measured by comparing the calibration curve with the results of the measurement sample.

[0043] <Gel Permeation Chromatography Conditions> · Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation) · Column: GMHHR-H + GMHHR-H (manufactured by Tosoh Corporation) · Eluent: 1 mmol Farmine DM20 (manufactured by Kao Corporation) / CHCl3 · Eluent flow rate: 1.0 mL / min · Column temperature: 40°C · Detector: RI · Sample concentration: 0.1% by volume (chloroform solution) · Sample injection volume: 100 mL

[0044] Also, among the fiber-forming polymers, it is preferable to use a water-insoluble polymer in terms of maintaining the shape of the fibers in the film-forming composition. The water-insoluble polymer refers to a polymer that has the property that when 1 g of the polymer is weighed in an environment of 1 atm and 23°C and then immersed in 10 g of deionized water, and after 24 hours, more than 0.5 g of the immersed polymer does not dissolve.

[0045] Examples of the water-insoluble polymer include completely saponified polyvinyl alcohol that can be insolubilized after film formation, partially saponified polyvinyl alcohol that can be crosslinked after film formation by using it in combination with a crosslinking agent, oxazoline-modified silicone such as poly(N-propanoylethyleneimine) graft-dimethylsiloxane / γ-aminopropylmethylsiloxane copolymer, polyvinyl acetal diethylaminoacetate, zein (the main component of corn protein), polyester resins such as polylactic acid (PLA) and 3-hydroxybutyrate-3-hydroxyhexanoate copolymer (PHBH), polybutylene succinate, polyglycolic acid, polycaprolactone, polyhydroxyalkanoic acid, acrylic resins such as polyacrylonitrile resin and polymethacrylic acid resin, polystyrene resin, polyvinyl butyral resin, polyvinyl acetal resin, polyethylene terephthalate resin (PET), polybutylene terephthalate resin, polyurethane resin, polyamide resin, polyimide resin, polyamideimide resin, polyolefin resins (such as polypropylene resin and polyethylene resin), various water-insoluble polypeptides (such as collagen, gelatin, fibrin, casein, and silk), water-insoluble polysaccharides or derivatives thereof (such as cellulose-based polymers), and the like. These water-insoluble polymers can be used alone or in combination of two or more.

[0046] Among these water-insoluble polymers, one or more selected from completely saponified polyvinyl alcohol that can be insolubilized after film formation, partially saponified polyvinyl alcohol that can be crosslinked after film formation by using it in combination with a crosslinking agent, acrylic resins such as polymethacrylic acid resin, polyvinyl butyral resin, polyurethane resin, polylactic acid (PLA), oxazoline-modified silicone such as poly(N-propanoylethyleneimine) graft-dimethylsiloxane / γ-aminopropylmethylsiloxane copolymer, polyvinyl acetal diethylaminoacetate, zein, polyolefin resin, and cellulose-based polymer can be used.

[0047] Among these, from the viewpoint of the adhesion of the resulting film, one or more selected from polyvinyl butyral resin, acrylic resin, polylactic acid, polyurethane resin, polyolefin resin, and cellulose-based polymer are more preferable.

[0048] Examples of the acrylic resin include methacrylic acid·methyl methacrylate copolymer (methacrylic acid copolymer S (e.g., Eudragit S100, manufactured by Evonik), methacrylic acid copolymer L (e.g., Eudragit L100, manufactured by Evonik), etc.), methyl acrylate·methyl methacrylate·methacrylic acid polymer (e.g., Eudragit FS30D, manufactured by Evonik), octylacrylamide·alkyl acrylate copolymer (e.g., DERMACRYL 79, manufactured by Nouryon), methacrylic acid·alkyl methacrylate·dimethylpolysiloxane block copolymer (e.g., Myblock Wako 101, manufactured by Fujifilm Wako Pure Chemical Corporation), methacrylic acid·1,1-dimethylethyl acrylate·ethyl acrylate copolymer (e.g., Luvimer 100P, manufactured by BASF SE) are preferable.

[0049] Examples of the polyolefin include polyethylene (PE), polypropylene (PP), polystyrene (PS), and the like.

[0050] Examples of water-insoluble polysaccharides or derivatives thereof include methylcellulose, ethylcellulose, methylhydroxypropylcellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, nitrocellulose, sodium cellulose sulfate, sodium carboxymethylcellulose, crystalline cellulose, powdered cellulose, hydroxyethylcellulose hydroxypropyl stearyl ether sodium hydroxypropyl sulfonate, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidized cellulose, regenerated cellulose (rayon, cupra, etc.), cellulose-based polymers such as hypromellose phthalate, hypromellose acetate succinate, chitosan, chitin, and the like. Among these, hypromellose phthalate and hypromellose acetate succinate are preferred.

[0051] Furthermore, from the perspectives of SDGs and ESG in particular, resins with reduced environmental impact are preferred. Examples of resins with reduced environmental impact include seawater-soluble resins, biodegradable resins, and natural polymers.

[0052] As the water-soluble resin, from the viewpoint of solubility in seawater, an acrylic resin, or a water-insoluble polysaccharide or its derivative is preferable. Examples of the acrylic resin include methacrylic acid·methyl methacrylate copolymer (methacrylic acid copolymer S (for example, Eudragit S100, manufactured by Evonik), methacrylic acid copolymer L (for example, Eudragit L100, manufactured by Evonik), etc.), methyl acrylate·methyl methacrylate·methacrylic acid polymer (for example, Eudragit FS30D, manufactured by Evonik), octylacrylamide·alkyl acrylate copolymer (for example, DERMACRYL 79, manufactured by Nouryon), methacrylic acid·alkyl methacrylate·dimethylpolysiloxane block copolymer (for example, Myblock Wako 101, manufactured by Fujifilm Wako Pure Chemical Corporation), methacrylic acid·1,1-dimethylethyl acrylate·ethyl acrylate copolymer (for example, Luvimer 100P, manufactured by BASF SE), etc. Examples of the water-insoluble polysaccharide or its derivative include cellulose-based polymers such as hypromellose phthalate and hypromellose acetate succinate.

[0053] As the biodegradable resin, polylactic acid, polybutylene succinate, polyglycolic acid, polycaprolactone, polyhydroxyalkanoic acid, 3-hydroxybutyrate-3-hydroxyhexanoate copolymer, cellulose-based polymer, regenerated cellulose, and polypeptide are preferable. In this specification, "biodegradable" means that the biodegradability of the polyester measured according to JIS K6953-1 is 30% or more.

[0054] Examples of the natural polymer include water-insoluble polypeptides (such as collagen, gelatin, fibrin, casein, silk, etc.), water-insoluble polysaccharides (such as cellulose-based polymers, chitosan, chitin, etc.).

[0055] The fiber of component (E) preferably consists of a fiber-forming polymer containing a methacrylic acid·methyl methacrylate copolymer.

[0056] Examples of the spinning method include the electrospinning method (electrostatic spinning method) and the melt blowing method, and the electrospinning method is preferable in terms of obtaining fibers with a small fiber diameter.

[0057] Examples of the means for shortening the fibers include cutting, shearing, crushing, pulverizing, disintegrating, or defibrating methods. For example, mechanical vortex pulverizers, impact crushers such as hammer crushers, jet pulverizers such as jet mills, media-type pulverizers such as ball mills and rod mills, dry pulverization using cutter mill pulverizers and disk mill pulverizers, and wet pulverization using media pulverizers and media-less pulverizers using a liquid medium, and these can be used in combination.

[0058] More preferable means for shortening the fibers include, for example, after producing a fiber aggregate in which nanofibers are entangled, such as a non-woven fabric, cutting the fiber aggregate into an appropriate size, and then using a mechanical vortex pulverizer, a cutter mill pulverizer, a disk mill pulverization, a wet high-speed shear type media-less pulverizer, or a wet high-pressure shear type media-less pulverizer. Examples of the fiber aggregate include those having a predetermined thickness such as a cotton-like body in addition to non-woven fabrics.

[0059] Subsequent to the above-mentioned shortening of the fibers, if necessary, the short fibers can be washed with an insoluble solvent and then filtered to extract short fibers made of a fiber-forming polymer. Ethanol is preferable as the solvent when the resin constituting the short fibers is an ester-based resin such as PLA, and water is preferable when the resin is an acrylic-based resin.

[0060] The content of component (E) in the external preparation for skin of the present invention is 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.25% by mass or more, from the viewpoints of enhancing the film strength and suppressing the permeation of substances. Also, from the viewpoints of smoothness during application and storage stability of the emulsified state, it is 10% by mass or less, preferably 7% by mass or less, more preferably 5% by mass or less, still more preferably 4% by mass or less, still more preferably 2% by mass or less, still more preferably 1% by mass or less.

[0061] In addition, the skin external preparation of the present invention may contain powders used in ordinary cosmetics such as coloring pigments and extender pigments. However, from the viewpoints of ensuring the strength of the dry film and suppressing substance permeation, the content thereof is preferably less than the content of component (E), and more preferably 50% by mass or less of the content of component (E).

[0062] In the skin external preparation of the present invention, friction occurs between the fibers and the film components in the formed film, and the strength of the pharmaceutical film is improved. Therefore, the ratio of the square of the average fiber diameter of component (E) to the content of component (E) (average fiber diameter of component (E)) 2 / (content of component (E)) [μm 2 / mass%] is preferably 0.0000045 or more, more preferably 0.01 or more, still more preferably 0.1 or more, and preferably 10 or less, more preferably 2 or less, still more preferably 1 or less, and still more preferably 0.5 or less. This ratio is an index of the cumulative length of the fibers of component (E) contained in the skin external preparation, and means that the larger this value, the shorter the cumulative length.

[0063] Also, the mass ratio (E) / (C) of component (E) and component (C) in the skin external preparation of the present invention is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more from the viewpoint of enhancing the film strength, and preferably 12 or less, more preferably 6 or less, still more preferably 4 or less from the viewpoints of smoothness during application and storage stability of the emulsified state.

[0064] Also, the mass ratio (E) / (D) of component (E) and component (D) water in the skin external preparation of the present invention is preferably 0.001 or more, more preferably 0.002 or more, still more preferably 0.003 or more from the viewpoints of enhancing the film strength and suppressing substance permeation, and preferably 0.3 or less, more preferably 0.1 or less, still more preferably 0.07 or less from the viewpoints of smoothness during application and storage stability of the emulsified state.

[0065] In addition, from the perspective that the mass ratio (E) / [(A)+(B)+(C)] of component (E) to the sum of component (A), component (B), and component (C) in the external preparation for skin of the present invention increases the contact frequency with the film-forming component and the friction as the fiber content ratio increases, it is preferably 0.01 or more, more preferably 0.02 or more, still more preferably 0.03 or more, and even more preferably 0.05 or more. Also, from the perspective of improving the storage stability of the emulsified state, it is preferably 2.0 or less, more preferably 1.5 or less, still more preferably 1.0 or less, and even more preferably 0.7 or less.

[0066] From the perspectives of enhancing film strength and barrier performance and improving the storage stability of the emulsified state, the specific surface area or cumulative length index of component (E) in the external preparation for skin (that is, (average fiber diameter of component (E)) 2 / (content of component (E)) [μm 2 / mass%]) preferably satisfies the above-mentioned preferred range, and the mass ratio (E) / [(A)+(B)+(C)] preferably satisfies the above-mentioned preferred range. Also, it is preferable that the average fiber length of component (E) and the mass ratio (E) / [(A)+(B)+(C)] satisfy the above-mentioned preferred range, and the cumulative length index of component (E) in the external preparation for skin satisfies the above-mentioned preferred range. Also, it is preferable that the average fiber length of component (E) and the mass ratio (E) / [(A)+(B)+(C)] satisfy the above-mentioned preferred range, and the average fiber diameter or specific surface area of component (E) satisfies the above-mentioned preferred range. Furthermore, it is preferable that all of these parameters satisfy the above-mentioned preferred range.

[0067] 〔Component (F): Medicinal ingredient〕 The external preparation for skin of the present invention can further contain a medicinal ingredient (excluding those corresponding to component (C)) as component (F). As the medicinal ingredient, an anti-inflammatory agent is preferable, and one or more selected from steroid anti-inflammatory agents, non-steroidal anti-inflammatory agents, and mucopolysaccharides or their derivatives are more preferable.

[0068] Among the components (F), as steroid anti-inflammatory agents, there are clobetasol propionate, diflorasone diacetate, mometasone furoate, betamethasone butyrate propionate, fluocinonide, betamethasone dipropionate, difluprednate, amcinonide, diflucortolone valerate, hydrocortisone butyrate propionate, deprodone propionate, dexamethasone propionate, dexamethasone valerate, betamethasone valerate, beclomethasone propionate, fluocinolone acetonide, prednisolone valerate acetate, triamcinolone acetonide, alclometasone propionate, clobetasol butyrate, hydrocortisone butyrate, prednisolone, dexamethasone acetate, hydrocortisone acetate, prednisolone acetate, hydrocortisone valerate, dexamethasone metasulfobenzoate sodium, prednisolone valerate, dexamethasone, hydrocortisone. Among these, betamethasone valerate, prednisolone valerate acetate, triamcinolone acetonide, prednisolone, dexamethasone acetate, hydrocortisone acetate, prednisolone acetate are preferred, and prednisolone valerate acetate, prednisolone, hydrocortisone acetate are more preferred.

[0069] Among the components (F), examples of non-steroidal anti-inflammatory agents include ufenamate, ibuprofen piconol, actarit, acemetacin, ampiroxicam, anfenac, ibuprofen, indomethacin, etodolac, ketoprofen, zaliprofen, diclofenac, sulindac, celecoxib, tiaprofenic acid, tenoxicam, naproxen, piroxicam, felbinac, pranoprofen, flurbiprofen, mefenamic acid, medico xib, meloxicam, mofezolac, lefe coxib, loxoprofen, lobenzarit, lornoxicam, and salts thereof. Among these, from the viewpoint of storage stability of the drug, one or more selected from ufenamate and ibuprofen piconol are preferred.

[0070] Examples of mucopolysaccharides or their derivatives among the components (F) include hyaluronic acid, chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, keratan sulfate, heparin, heparin-like substances, carboxymethyl chitin, and the like. Examples of salts of mucopolysaccharides or their derivatives include alkali metal salts such as lithium salts, sodium salts, and potassium salts; alkaline earth metal salts such as magnesium salts and calcium salts; ammonium salts; alkanolamine salts such as triethanolamine salts and diisopropanolamine salts; and basic amino acid salts such as lysine salts, arginine salts, and histidine salts. These can be used alone or in combination of two or more. Among these, heparin-like substances are preferred.

[0071] Heparin-like substances are substances also known as mucopolysaccharide polysulfates or heparinoids, and are obtained by polysulfating a mucopolysaccharide having a disaccharide composed of D-glucuronic acid and N-acetyl-D-galactosamine as a repeating unit. As heparin-like substances, heparin-like substances described in the Japanese Pharmaceutical Excipients Standards 2002 are preferred.

[0072] The average molecular weight of the heparin-like substance is not particularly limited, but from the viewpoint of drug efficacy such as moisturizing effect, 1000 to 1,000,000 Mw is preferable, and 5000 to 100,000 Mw is particularly preferable. Further, the amount (%) of the organic sulfate group in the heparin-like substance is not particularly limited, but from the viewpoint of drug efficacy such as moisturizing effect, 20 to 40% is preferable, and 25 to 38% is more preferable. The amount of the organic sulfate group is measured by the method described in the section of "Heparin-like substance" in the Japanese Pharmaceutical Excipients Standards 2002.

[0073] From the viewpoint of the effectiveness of the drug, the content of component (F) in the external preparation for skin of the present invention is preferably 0.025% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.10% by mass or more. Further, from the viewpoint of the storage stability of the emulsified state, it is preferably 6.5% by mass or less, more preferably 6.0% by mass or less, still more preferably 5.5% by mass or less.

[0074] More specifically, when component (F) is a steroid anti-inflammatory agent, its content is preferably 0.025% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.10% by mass or more from the same viewpoints as above. Also, it is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.3% by mass or less. When component (F) is a non-steroid anti-inflammatory agent, its content is preferably 0.5% by mass or more, more preferably 2.5% by mass or more, still more preferably 4.5% by mass or more from the same viewpoints as above. Also, it is preferably 6.5% by mass or less, more preferably 6.0% by mass or less, still more preferably 5.5% by mass or less. When component (F) is a mucopolysaccharide or its derivative, its content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more from the same viewpoints as above. Also, it is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less.

[0075] [Component (G): Ceramides] In the external preparation for skin of the present invention, ceramides can be contained as component (G) in order to further improve the skin barrier function.

[0076] Examples of ceramides include one or more selected from natural ceramides and pseudo-ceramides. Specific examples of natural ceramides include ceramide Types 1 to 7 in which sphingosine, dihydrosphingosine, phytosphingosine or sphingadienine is amidated, and further include N-alkyl derivatives (for example, N-methyl derivatives) thereof. Specific examples of pseudo-ceramides include (N-hexadecyloxyhydroxypropyl)-N-hydroxyhexadecanamide, (N-hexadecyloxyhydroxypropyl)-N-hydroxydecanoamide, and N-[2-(2,3-dihydroxypropyloxy)-3-hexadecyloxypropyl]-N-3-methoxypropyltetradecaneamide.

[0077] The content of component (G) in the external preparation for skin of the present invention is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, still more preferably 2.0% by mass or more from the viewpoint of further improving the skin barrier function, and is preferably 6.0% by mass or less, more preferably 5.0% by mass or less, still more preferably 4.0% by mass or less from the viewpoint of good elongation during application.

[0078] 〔pH〕 The pH of the external preparation for skin of the present invention is preferably 7.0 or less, more preferably 6.5 or less, still more preferably 6.0 or less from the viewpoints of adjusting to the pH environment of normal skin and improving the stability of component (F), and is preferably 4.0 or more, more preferably 4.2 or more, still more preferably 4.4 or more from the viewpoint of reducing skin irritation.

[0079] When the topical skin preparation of the present invention contains a steroid anti-inflammatory agent as component (F), its pH is preferably 5.5 or less, more preferably 5.0 or less, still more preferably 4.8 or less, from the viewpoint of the stability of component (F), and preferably 4.0 or more, more preferably 4.2 or more, still more preferably 4.4 or more, from the viewpoint of the storage stability of the emulsified state.

[0080] When the topical skin preparation of the present invention contains a non-steroid anti-inflammatory agent as component (F), its pH is preferably 7.0 or less, more preferably 6.5 or less, still more preferably 6.0 or less, from the viewpoint of the storage stability of the emulsified state, and preferably 4.0 or more, more preferably 4.5 or more, still more preferably 5.0 or more, from the same viewpoint.

[0081] When the topical skin preparation of the present invention contains a mucopolysaccharide or its derivative as component (F), its pH is preferably 7.0 or less, more preferably 6.5 or less, still more preferably 6.0 or less, from the viewpoint of the storage stability of the emulsified state, and preferably 4.0 or more, more preferably 4.5 or more, still more preferably 5.0 or more, from the same viewpoint.

[0082] 〔Other components〕 The topical skin preparation of the present invention can appropriately contain components other than the aforementioned components, such as hydrocarbon oils, ether oils, ester oils, silicone oils, fluorine-based oils, waxes, cholesterol derivatives, phytosterol derivatives, dipentaerythritol fatty acid esters, triglycerides, lanolin, lanosterol derivatives, petrolatum and other oils other than component (A), polyhydric alcohols such as glycerin and propylene glycol, thickeners, bactericides, moisturizers, wetting agents, coloring agents, preservatives, feel improvers, powders, fragrances, anti-inflammatory agents, whitening agents, antiperspirants, ultraviolet absorbers, antioxidants, etc.

[0083] The external preparation for skin of the present invention contains components (A) to (E) in a predetermined ratio. When applied to the skin and the moisture evaporates, a structure of an emulsion excellent in barrier performance, preferably a dry film having a lamellar structure, can be formed on the skin surface. The lamellar structure can be confirmed by wide-angle X-ray diffraction, polarized microscopy, etc.

[0084] The external preparation for skin of the present invention is applied in an appropriate amount to the skin, preferably to any of the face, neck, body, limbs, etc., more preferably to the skin of the parts such as the neck, back, arms, and legs that are rubbed by clothes. However, it may be spread on the target part by hand or directly applied to the target part. The application amount is preferably about 0.5 g if it is the area of two palms.

[0085] Regarding the embodiments described above, the preferred embodiments of the present invention are further disclosed below.

[0086] <1> An external preparation for skin containing the following components (A) to (E). (A) One or more selected from aliphatic alcohols having 14 to 20 carbon atoms (B) One or more selected from polyhydric alcohol fatty acid ester type nonionic surfactants (C) One or more selected from ionic surfactants (D) Water (E) Fibers having an average fiber diameter of 0.001 μm or more and 7 μm or less and an average fiber length of 0.01 μm or more and 1000 μm or less, 0.01 mass% or more and 10 mass% or less

[0087] <2> The external preparation for skin according to <1>, wherein component (A) is preferably a linear aliphatic alcohol and / or a saturated aliphatic alcohol, more preferably a linear saturated aliphatic alcohol, and still more preferably one or more selected from myristyl alcohol, cetyl alcohol, stearyl alcohol, and arachidyl alcohol.

[0088] <3> Component (A) is a combination of (a1) a short-chain (having 14 or more and less than 18 carbon atoms) aliphatic alcohol and (a2) a long-chain (having 18 or more and 20 or less carbon atoms) aliphatic alcohol, and the mass ratio (a1) / (a2) thereof is preferably 0.1 or more, more preferably 0.6 or more, still more preferably 1.0 or more, and is also preferably 7.0 or less, more preferably 5.0 or less, still more preferably 3.0 or less, still more preferably 2.5 or less, the skin external preparation according to <1> or <2>.

[0089] <4> The content of component (A) is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, still more preferably 0.8% by mass or more, and is also preferably 4.0% by mass or less, more preferably 3.0% by mass or less, still more preferably 2.5% by mass or less, still more preferably 2.0% by mass or less, the skin external preparation according to any one of <1> to <3>.

[0090] <5> Component (B) is preferably at least one selected from sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan mono-fatty acid, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene fatty acid ester and polyoxyethylene hydrogenated castor oil, the skin external preparation according to any one of <1> to <4>.

[0091] <6> Component (B) is a combination of (b1) at least one polyhydric alcohol fatty acid ester having an HLB of 3 or more and 7 or less, more preferably 4 or more and 6 or less, and (b2) at least one polyhydric alcohol fatty acid ester having an HLB of 11 or more and 16, more preferably 13 or more and 15 or less, and the mass ratio (b1) / (b2) thereof is preferably 0.25 or more, more preferably 0.4 or more, still more preferably 0.6 or more, and is also preferably 4.0 or less, more preferably 2.0 or less, still more preferably 1.5 or less, the skin external preparation according to any one of <1> to <5>.

[0092] <7> The content of component (B) is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, and is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less. <1> ~ <6> 13. The skin topical preparation according to claim 12.

[0093] <8> The mass ratio (A) / (B) of the component (A) to the component (B) is preferably 0.3 or more, more preferably 0.35 or more, even more preferably 0.4 or more, and is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.5 or less. <1> ~ <7> 13. The skin topical preparation according to claim 12.

[0094] <9> Component (C) preferably contains one or more selected from anionic surfactants, cationic surfactants, and amphoteric surfactants, more preferably one or more selected from anionic surfactants and amphoteric surfactants. <1> ~ <8> 13. The skin topical preparation according to claim 12.

[0095] <10> The component (C) is preferably one or more selected from N-acylamino acids, N-acyltaurines and their salts, and phospholipids, and more preferably one or more selected from sodium N-acylglutamate, sodium N-acylmethyltaurine, and hydrogenated lecithin. <1> ~ <9> 13. The skin topical preparation according to claim 12.

[0096] <11> The content of component (C) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and is preferably 1.0% by mass or less, more preferably 0.8% by mass or less, even more preferably 0.6% by mass or less, even more preferably 0.5% by mass or less. <1> ~ <10> 13. The skin topical preparation according to claim 12.

[0097] <12> The mass ratio (A) / (C) of component (A) to component (C) is preferably 1.0 or more, more preferably 1.5 or more, still more preferably 2.0 or more, and is preferably 15 or less, more preferably 10 or less, still more preferably 7.0 or less. The external preparation for skin according to any one of <1> to <11>.

[0098] <13> The content of component (D) is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less. The external preparation for skin according to any one of <1> to <12>.

[0099] <14> The average fiber diameter of the fiber of component (E) is preferably 0.05 μm or more, more preferably 0.1 μm or more, still more preferably 0.2 μm or more, and is preferably 5 μm or less, more preferably 4 μm or less, still more preferably 3 μm or less, still more preferably 2.0 μm or less, still more preferably 1.5 μm or less. The external preparation for skin according to any one of <1> to <13>.

[0100] <15> The average fiber length of the fiber of component (E) is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 10 μm or more, still more preferably 50 μm or more, and is preferably 750 μm or less, more preferably 600 μm or less, still more preferably 500 μm or less, still more preferably 300 μm or less, still more preferably 250 μm or less, still more preferably 150 μm or less. The external preparation for skin according to any one of <1> to <14>.

[0101] <16> The aspect ratio (average fiber length / average fiber diameter) of the fibers of component (E) is preferably 5 or more, more preferably 10 or more, still more preferably 50 or more, still more preferably 100 or more, still more preferably 200 or more, and is preferably 10000 or less, more preferably 5000 or less, still more preferably 3000 or less, still more preferably 1000 or less, still more preferably 500 or less, a skin external preparation according to any one of <1> to <15>.

[0102] <17> The specific surface area (surface area / unit volume) of the fibers of component (E) is preferably 0.5 or more, more preferably 1 or more, still more preferably 2 or more, still more preferably 4 or more, and is preferably 1500 or less, more preferably 1000 or less, still more preferably 500 or less, still more preferably 100 or less, still more preferably 50 or less, still more preferably 30 or less, a skin external preparation according to any one of <1> to <16>.

[0103] <18> The number of component (E) in 1 mL of a 0.01 mass% aqueous solution of the skin external preparation is preferably 1.0×10 5 or more, more preferably 2.0×10 5 or more, still more preferably 5.0×10 5 or more, still more preferably 1.0×10 6 or more, and is preferably 1.0×10 15 or less, more preferably 1.0×10 14 or less, still more preferably 1.0×10 8 or less, a skin external preparation according to any one of <1> to <17>.

[0104] <19> The component (E) is preferably a fiber composed of a water-insoluble polymer, more preferably completely saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, oxazoline-modified silicone, polyvinyl acetal diethylaminoacetate, zein (the main component of corn protein), polyester resin, polybutylene succinate, polyglycolic acid, polycaprolactone, polyhydroxyalkanoic acid, polyacrylonitrile resin, acrylic resin, polystyrene resin, polyvinyl butyral resin, polyvinyl acetal resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyurethane resin, polyamide resin, polyimide resin, polyamideimide resin, polyolefin resin, water-insoluble polypeptide, water-insoluble polysaccharide or a derivative thereof, and is a fiber composed of one or more selected from the above, and is a skin external preparation according to any one of <1> to <18>.

[0105] <20> The component (E) is preferably composed of a fiber-forming polymer containing an environmentally friendly resin, and is a skin external preparation according to any one of <1> to <19>.

[0106] <21> The environmentally friendly resin is one or more selected from seawater-soluble resin, biodegradable resin and natural polymer, and is a skin external preparation according to <20>.

[0107] <22> The component (E) is composed of a fiber-forming polymer containing a methacrylic acid-methyl methacrylate copolymer, and is a skin external preparation according to any one of <1> to <21>.

[0108] <23> The component (E) is preferably a fiber produced by an electrospinning method or a melt blowing method, and is a skin external preparation according to any one of <1> to <22>.

[0109] <24> The content of component (E) is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.25% by mass or more, and preferably 7% by mass or less, more preferably 5% by mass or less, still more preferably 4% by mass or less, still more preferably 2% by mass or less, still more preferably 1% by mass or less. The external preparation for skin according to any one of <1> to <23>.

[0110] <25> The ratio of the square of the average fiber diameter of component (E) to the content of component (E) (average fiber diameter of component (E)) 2 / (content of component (E)) [μm 2 / mass%] is preferably 0.0000045 or more, more preferably 0.01 or more, still more preferably 0.1 or more, and preferably 10 or less, more preferably 2 or less, still more preferably 1 or less, still more preferably 0.5 or less. The external preparation for skin according to any one of <1> to <24>.

[0111] <26> The mass ratio (E) / (C) of component (E) and component (C) is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, and preferably 12 or less, more preferably 6 or less, still more preferably 4 or less. The external preparation for skin according to any one of <1> to <25>.

[0112] <27> The mass ratio (E) / (D) of component (E) and component (D) is preferably 0.001 or more, more preferably 0.002 or more, still more preferably 0.003 or more, and preferably 0.3 or less, more preferably 0.1 or less, still more preferably 0.07 or less. The external preparation for skin according to any one of <1> to <26>.

[0113] <28> The mass ratio of component (E) to the sum of component (A), component (B) and component (C), (E) / [(A)+(B)+(C)], is preferably 0.01 or more, more preferably 0.02 or more, still more preferably 0.03 or more, and even more preferably 0.05 or more, and is preferably 2.0 or less, more preferably 1.5 or less, still more preferably 1.0 or less, and even more preferably 0.7 or less. The external preparation for skin according to any one of <1> to <27>.

[0114] <29> Preferably, further, the external preparation for skin according to any one of <1> to <28> contains a medicinal ingredient (excluding those corresponding to component (C)) as component (F).

[0115] <30> Component (F) is preferably one or more selected from anti-inflammatory agents, more preferably steroid anti-inflammatory agents, non-steroidal anti-inflammatory agents and mucopolysaccharides or their derivatives. The external preparation for skin according to <29>.

[0116] <31> The content of component (F) is preferably 0.025% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.10% by mass or more, and is preferably 6.5% by mass or less, more preferably 6.0% by mass or less, still more preferably 5.5% by mass or less. The external preparation for skin according to <29> or <30>.

[0117] <32> Preferably, component (F) is a steroid anti-inflammatory agent, and its content is preferably 0.025% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.10% by mass or more, and is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.3% by mass or less. The external preparation for skin according to <29> or <30>.

[0118] <33> Preferably, component (F) is a non-steroidal anti-inflammatory agent, and its content is preferably 0.5% by mass or more, more preferably 2.5% by mass or more, still more preferably 4.5% by mass or more, and preferably 6.5% by mass or less, more preferably 6.0% by mass or less, still more preferably 5.5% by mass or less, the skin external preparation according to <29> or <30>.

[0119] <34> Preferably, component (F) is a mucopolysaccharide or a derivative thereof, and its content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more, and preferably 3.0% by mass or less, more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less, the skin external preparation according to <29> or <30>.

[0120] <35> Preferably, further containing ceramides as component (G), the skin external preparation according to any one of <1> to <34>.

[0121] <36> The content of component (G) is preferably 1.0% by mass or more, more preferably 1.5% by mass or more, still more preferably 2.0% by mass or more, and preferably 6.0% by mass or less, more preferably 5.0% by mass or less, still more preferably 4.0% by mass or less, the skin external preparation according to <35>.

[0122] <37> The pH is preferably 7.0 or less, more preferably 6.5 or less, still more preferably 6.0 or less, and preferably 4.0 or more, more preferably 4.2 or more, still more preferably 4.4 or more, the skin external preparation according to any one of <1> to <36>.

[0123] <38> Preferably, the topical skin preparation contains a steroid anti-inflammatory agent as component (F), and the pH of the topical skin preparation is preferably 5.5 or less, more preferably 5.0 or less, still more preferably 4.8 or less, and is also preferably 4.0 or more, more preferably 4.2 or more, still more preferably 4.4 or more. The topical skin preparation according to any one of <1> to <36>.

[0124] <39> Preferably, the topical skin preparation contains a non-steroid anti-inflammatory agent as component (F), and the pH of the topical skin preparation is preferably 7.0 or less, more preferably 6.5 or less, still more preferably 6.0 or less, and is also preferably 4.0 or more, more preferably 4.5 or more, still more preferably 5.0 or more. The topical skin preparation according to any one of <1> to <36>.

[0125] <40> Preferably, the topical skin preparation contains mucopolysaccharide or a derivative thereof as component (F), and the pH of the topical skin preparation is preferably 7.0 or less, more preferably 6.5 or less, still more preferably 6.0 or less, and is also preferably 4.0 or more, more preferably 4.5 or more, still more preferably 5.0 or more. The topical skin preparation according to any one of <1> to <36>.

[0126] <41> A method for forming a film on the skin, which comprises applying the topical skin preparation according to any one of <1> to <40> to the skin, preferably the face, neck, body or limbs, more preferably the neck, back, arms or legs.

Example

[0127] Production Example 1 of Component (E) (1) Methacrylic acid copolymer S (manufactured by Evonik, Eudragit S100) was dissolved in ethanol and DMSO (mass ratio 80:30) to obtain a 16% by mass solution. Using the apparatus for the electrospinning method shown in FIG. 1, a nanofiber sheet was formed on the surface of the collector. The production conditions of the nanofibers are as follows. ·Applied voltage: nozzle voltage 30 kV, collection voltage -30 kV · Distance between capillary and collector: 800 mm · Aqueous solution discharge rate: 20 g / Hour · Environment: 25°C, 30% RH (2) After appropriately cutting the obtained nanofiber sheet, a dispersing blade was attached to a stirring system (manufactured by Primix Corporation, Labolution (registered trademark)), and shearing was performed at 3000 rpm for 3 minutes to obtain fibers.

[0128] Production Example 2 of Component (E) (1) Using a meltblowing apparatus, nanofibers were formed from low molecular weight polyethylene (manufactured by Sanyo Chemical Industries, Sunwax 161-P). The production conditions of the nanofibers are as follows. · Resin temperature: about 190 - 195°C · Hot air temperature: 300°C · Hot air volume: 350 L / min. · Discharge rate: about 1 g / min (2) After appropriately cutting the obtained nanofibers, a rotor was attached to an in-line type dispersion and pulverizer (manufactured by Shinmaru Enterprises Corporation, Magic Lab), and shearing was performed at a peripheral speed of 32 m / s, a clearance of 0.32 mm for 10 minutes to obtain fibers.

[0129] Production Example 3 of Component (E) (1) A cross nozzle (nozzle diameter 160 μm) was attached to a Nanovator (manufactured by Yoshida Kikai Kogyo Co., Ltd.), and low-substituted hydroxypropyl cellulose (manufactured by Shin-Etsu Chemical Co., Ltd., LODICEL) was defibrated at a pressure of 150 Mpa for 5 passes to obtain fibers.

[0130] Examples 1 - 32, Comparative Examples 1 - 7 According to the following Production Method 1 or 2, external skin preparations shown in Tables 1 - 8 were prepared, and "stability of emulsion state", "feeling of use during application", "strength of dry film", and "ability to suppress water vapor transpiration of formulation film" were evaluated according to the following methods and criteria.

[0131] (Production Method 1) After dissolving the component (C) and the aqueous phase component shown in Tables 1 and 2 at 75 to 95°C, the component (A), component (B), component (F), and component (G) and the oil phase component were added, cooled gradually, stirred at 60 to 70°C (3000 r / m) using a homomixer, and further cooled gradually to 35°C. Then, the component (E) was added and stirred (7000 r / m) using a homomixer to produce an oil-in-water type emulsified composition.

[0132] (Production Method 2) To the oil phase in which the components (A), (B), (C), and (G) shown in Tables 3 to 8 and the oil phase component were dissolved at 75 to 95°C, while stirring with a homomixer (7000 r / m), the aqueous phase in which the components (F) and the aqueous phase component shown in Tables 3 to 8 were uniformly dissolved was gradually added for emulsification. After cooling to 35°C, the component (E) was added and stirred (7000 r / m) using a homomixer to produce an oil-in-water type emulsified composition. The pH of the produced emulsified composition was measured at 25°C as a stock solution (manufactured by HORIBA, LAQUA F-74).

[0133] (1) Stability of the emulsified state The state (any of creaming, aggregation, and water separation) of the composition after storage at room temperature for 1 month was visually judged according to the following criteria. A: No change B: Slight change in state C: Obvious change in state

[0134] (2) Feeling of use during application (smoothness, good elongation) Ten professional panelists conducted a sensory evaluation on the smoothness when applying each topical skin preparation and judged according to the following criteria. A: 7 to 10 panelists evaluated it as good B: 5 or 6 panelists evaluated it as good C: 3 or 4 panelists evaluated it as good D: 1 or 2 panelists evaluated it as good E: No panelist evaluated it as good

[0135] (3) Strength of the dried film The strength of the dried film was evaluated by rheological analysis of the dried film. Based on the strain-stress response, the stress value corresponding to the strain at which irreversible changes appeared in the film was analyzed and shown as a relative value with respect to the stress when the fiber content was 0%. For the measurement, MCR301 manufactured by Anton Paar was used as a rotational rheometer, and the measurement was carried out at 40 °C in an environment open to the atmosphere. For the topical preparation, a strain within the linear strain region was applied within the range of angular frequencies from 628 to 0.000628 s -1 This measurement was performed after the volatilization of the volatile components contained in the topical preparation had generally ended, and the strain dependence of the shear stress was determined when measuring up to the non-linear strain region of the topical preparation. For the topical preparation, a shear rate in the range of 0.0001 to 1000 s -1 was applied stepwise from a small rate to a large rate. Among the strain and stress at the point where the stress-strain dependence starts to deviate from the linear strain region, the stress was used for analysis as the dried film strength.

[0136] (4) Suppression of water evaporation through the formulation film The water content in the formulation film was calculated and evaluated from the weight change when the formulation film was dried on artificial leather under the condition of 32 °C. It was evaluated as a relative value with respect to the water amount in the formulation film when the fiber content was 0%.

[0137] (5) Residual amount of the drug on the skin After applying the formulation to the inner part of the forearm, the residual amount of component (F) was analyzed and evaluated when living while wearing long-sleeved clothing that closely adheres to the skin so as to receive clothing rubbing. The analysis of the residual amount of component (F) was performed by quantifying component (F) in the sample by HPLC using, as an analysis sample, the one collected by wiping the skin surface 3.5 hours after the formulation application with a cotton swab impregnated with ethanol. The evaluation conditions are as follows. · Formulation application amount: 2 mg / cm 2 · Formulation application area: 9 cm 2 (3 cm × 3 cm) · Formulation drying time: 10 min. <HPLC measurement conditions> · Measuring device: Prominence-i LC-2030 (manufactured by Shimadzu Corporation) · Column: l-column2, ODS, particle size 5 μM, 150 mm × 4.6 mm (manufactured by the National Institute of Advanced Industrial Science and Technology) · Eluent: methanol: water = 10:3 · Eluent flow rate: 1.0 mL / min · Column temperature: 40 °C · Detector: UV (detection wavelength 243 nm) · Sample injection volume: 5 μL

[0138]

Table 1

[0139]

Table 2

[0140]

Table 3

[0141]

Table 4

[0142]

Table 5

[0143]

Table 6

[0144]

Table 7

[0145]

Table 8

Description of Symbols

[0146] 10 Electrostatic spraying device 11 Syringe 12 High-voltage source 13 Conductive collector 11a Cylinder 11b Piston 11c Capillary

Claims

1. A topical skin preparation containing the following components (A) to (E). (A) One or more selected from aliphatic alcohols having 14 to 20 carbon atoms (B) A polyhydric alcohol fatty acid ester type nonionic surfactant composed of (b1) one or more polyhydric alcohol fatty acid esters having an HLB of 3 or more and 7 or less and (b2) one or more polyhydric alcohol fatty acid esters having an HLB of 11 or more and 16, wherein the mass ratio (b1) / (b2) thereof is 0.25 or more and 4.0 or less, and one or more selected from polyhydric alcohol fatty acid ester type nonionic surfactants (C) One or more selected from ionic surfactants (D) Water (E) 0.01% by mass or more and 10% by mass or less of fibers having an average fiber diameter of 0.001 μm or more and 7 μm or less and an average fiber length of 0.01 μm or more and 1000 μm or less

2. The topical skin preparation according to claim 1, wherein the content of component (C) is 0.1% by mass or more and 1.0% by mass or less.

3. The topical skin preparation according to claim 1 or 2, wherein the mass ratio (A) / (B) of component (A) and component (B) is 0.3 or more and 3.0 or less.

4. The topical skin preparation according to claim 3, wherein the mass ratio (A) / (B) of component (A) and component (B) is 0.35 or more and 2.0 or less.

5. The topical skin preparation according to any one of claims 1 to 4, wherein the mass ratio (A) / (C) of component (A) and component (C) is 1.0 or more and 15 or less

6. The topical skin preparation according to any one of claims 1 to 5, containing a medicinal ingredient (excluding those corresponding to component (C)) as component (F).

7. The topical skin preparation according to claim 6, wherein the content of component (F) is 0.025% by mass or more and 6.5% by mass or less.

8. The topical skin preparation according to any one of claims 1 to 7, wherein component (C) is one or more selected from N-acyl amino acids, N-acyl taurines and their salts, and phospholipids.

9. The topical skin preparation according to claim 8, wherein component (C) is one or more selected from sodium N-acyl glutamate, sodium N-acyl methyl taurine and hydrogenated lecithin.

10. The topical skin preparation according to any one of claims 1 to 9, containing ceramides as component (G).

11. The topical skin preparation according to any one of claims 1 to 10, wherein component (E) is a fiber of a water-insoluble polymer.

12. The external preparation for skin according to any one of claims 1 to 11, wherein the component (E) is an electrospun fiber or a meltblown fiber.

13. The external preparation for skin according to any one of claims 1 to 12, wherein the component (E) is a fiber composed of a polysaccharide or a derivative thereof.

14. The external preparation for skin according to any one of claims 1 to 13, wherein the component (E) is a fiber having an average fiber diameter of 0.1 μm or more and 2.0 μm or less and an average fiber length of 10 μm or more and 300 μm or less.

15. The external preparation for skin according to any one of claims 1 to 14, wherein the content of the component (E) is 0.1% by mass or more and 4% by mass or less.

16. The external preparation for skin according to any one of claims 1 to 15, wherein the mass ratio (E) / [(A)+(B)+(C)] of the component (E) to the sum of the components (A), (B) and (C) is 0.01 or more and 2.0 or less.

17. The external preparation for skin according to any one of claims 1 to 16, wherein the pH is 7.0 or less.

18. A method for forming a film on the skin, which comprises applying the external preparation for skin according to any one of claims 1 to 17 to the skin.

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