Skin external preparation

Abstract

To provide a skin external preparation which exhibits excellent bactericidal or virucidal properties and has low skin irritation.SOLUTION: There is provided a skin external preparation obtained by storing a skin external preparation composition in a fixed quantity discharging container, wherein the composition comprises one or more acids and salts thereof (A) selected from the group consisting of lactic acid, pyruvic acid and urocanic acid and when a component present in an acid form of the acids present in the composition is defined as a component (A1), the content of the component (A1) in the composition discharged from the fixed quantity discharging container by one dispensing operation is 0.05 mg or more and 80 mg or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a topical skin preparation. [Background technology]

[0002] Recent studies have shown that contact transmission is a common route of bacterial or viral infection in daily life. Contact transmission primarily occurs when hands come into contact with infected individuals, doorknobs, handles, dishes, toys, other everyday items, interior furnishings, and other objects.

[0003] There is a need for methods to prevent contact transmission of bacteria or viruses through such everyday contact activities. One known method for preventing contact transmission of bacteria or viruses through the hands is to apply alcohol-based disinfectants to the hands to kill and disinfect them. However, alcohols such as ethanol used as disinfectants are highly volatile, and their effectiveness in providing bactericidal and antiviral effects to the hands is not sufficiently sustained.

[0004] Therefore, methods are being considered to pre-apply protective functions against bacteria or viruses to the hands. According to these methods, a continuous effect of preventing infection by bacteria or viruses can be obtained, making it possible to prevent contact infection even in environments where there are no handwashing facilities, such as when going out. This is particularly preferable because it can prevent infection even when repeatedly coming into contact with objects to which bacteria or viruses have adhered.

[0005] Patent Document 1 discloses that topical compositions such as hand sanitizer compositions containing niacinamide or its derivatives; a first quaternary ammonium salt including didecyldimethylammonium chloride; a second quaternary ammonium salt such as benzethonium chloride, benzalkonium chloride, or polydiallyldimethylammonium chloride; and a base acceptable as a cosmetic can provide long-lasting antibacterial effects. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2019-518720 [Overview of the project] [Problems that the invention aims to solve]

[0007] The bactericidal and antimicrobial agents used in the technology disclosed in Patent Document 1 have substantially limited amounts that can be incorporated into skin compositions from the viewpoint of safety for the human body. Therefore, the bactericidal or antiviral activity of the skin by the bactericidal or antimicrobial agents is not sufficient, and further improvements have been desired. The present invention aims to provide a topical skin preparation that exhibits excellent bactericidal or antiviral properties and has low skin irritation. [Means for solving the problem]

[0008] The present inventors have found that the above problem can be solved by using a topical skin preparation comprising a composition for topical skin use containing a predetermined organic acid or a salt thereof, housed in a container capable of dispensing it in a manner that satisfies predetermined requirements. In other words, the present invention relates to the following. [1] A topical skin preparation composition contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). A topical skin preparation in which, when the acid present in the composition is defined as component (A1), the amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less. [2] A method for supplying one or more acids or salts thereof (A) selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid to an application site on the skin surface, comprising the following steps (I) and (II) in order. Step (I): A step of cleaning the application area. Step (II): A step of supplying the composition containing component (A) to the application site by discharging the composition from a quantitative discharging container containing the composition in a single discharging operation, wherein, when the acid present in the composition is in acid form (A1), the content of component (A1) in the composition discharged from the quantitative discharging container in a single discharging operation is 0.05 mg or more and 80 mg or less. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a topical skin preparation that exhibits excellent bactericidal or antiviral properties and has low skin irritation. [Modes for carrying out the invention]

[0010] [Definition] In this specification, "component present in acid form (A1)" means one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid derived from component (A), which are present in the composition as lactic acid, pyruvic acid, and urocanic acid. Furthermore, in the following description, one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid derived from component (A), which are present in the composition as lactate ions, pyruvate ions, and urocanic acid ions, are also referred to as "component present in dissociated form (A2)".

[0011] In this specification, "bactericidal or virucidal activity" refers to the bactericidal or virucidal activity of the skin surface to which the topical skin preparation composition has been applied. For example, bactericidal activity against Serratia bacteria can be specifically evaluated by the method described in the examples. Bactericidal and virucidal activity against other bacteria and viruses can be evaluated with reference to common technical knowledge.

[0012] In this specification, "exhibiting bactericidal or virucidal properties" encompasses the concepts of: (1) bactericidal and virucidal effects exhibited against bacteria and viruses attached to the skin surface after the topical skin preparation composition is applied to the skin surface; (2) bactericidal and virucidal effects exhibited against bacteria and viruses attached to the skin by applying the composition; (3) effects that prepare the skin to be free from the transmission of bacteria and viruses; (4) effects that protect the skin from bacteria and viruses and keep it hygienic; (5) effects that prevent the transmission of bacteria and viruses through the skin and contact infection; and (6) effects that enhance the skin's ability to protect against infection by bacteria and viruses.

[0013] [Topical skin preparations] The present invention relates to a topical skin preparation comprising a topical skin preparation composition (hereinafter also simply referred to as "composition") contained in a quantitative dispensing container, wherein the composition contains one or more acids or salts thereof selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, and when the acid present in the composition exists in acid form, the content of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less. In other words, the topical skin preparation of the present invention means a topical skin product comprising the topical skin preparation composition and the quantitative dispensing container. The topical skin preparation of the present invention, having the above-described structure, exhibits excellent bactericidal or antiviral properties and has low skin irritation.

[0014] The reason why the topical skin preparation of the present invention produces the above-mentioned effects is not entirely clear, but it is thought to be as follows. The topical skin preparation of the present invention uses component (A) as a bactericidal or antiviral component. Lactic acid, pyruvic acid, and urocanic acid, which are component (A), are originally present on the human skin, such as being supplied from sweat glands. The inventors have found that, particularly on the fingers, they play a bactericidal and antiviral function against bacteria, viruses, etc. Therefore, it is considered that the topical skin preparation composition containing component (A) can be a composition with low skin irritation and high human body safety while having bactericidal or antiviral properties. Regarding the above-mentioned bactericidal or antiviral properties, it is known that in a composition containing component (A), the lower the pH, the higher the bactericidal or antiviral properties. For example, lactic acid, which is component (A), can exist in the form of an acid type (CH3CH(OH)COOH) and a dissociated type (CH3CH(OH)COO - ) in an aqueous solution. Since the acid type has no charge and is easily taken into bacteria or viruses, it is considered that the acid type exhibits higher bactericidal or antiviral properties.

[0015] On the other hand, even in a composition containing component (A), there is a concern that a composition in a low pH range may cause skin irritation. Therefore, the inventors focused on the content of component (A1) that exists in the acid type among the above acids in the topical skin preparation composition applied to the skin. Then, by containing the topical skin preparation composition containing component (A) in a quantitative discharge container and setting the component (A1) in the composition discharged by one discharge operation from the container within a predetermined range, it was found that excellent bactericidal or antiviral properties can be exhibited and skin irritation can be reduced.

[0016] The topical skin preparation of the present invention comprises a topical skin preparation composition contained in a quantitative dispensing container, wherein the amount of component (A1) contained in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less. By having the content of component (A1) in the dispensed composition within the above range, the topical skin preparation exhibits excellent bactericidal or antiviral properties and has low skin irritation. Furthermore, since the content of component (A1) contained in the dispensed composition is controlled to be within the above range in a single dispensing operation of the topical skin preparation of the present invention, it is possible to easily and stably supply the skin with an amount of component (A1) that exhibits excellent bactericidal or antiviral properties while achieving low skin irritation.

[0017] The content of component (A1) in the composition dispensed in a single dispensing operation from a quantitative dispensing container is preferably 0.1 mg or more, more preferably 0.2 mg or more, even more preferably 0.4 mg or more, even more preferably 0.5 mg or more, even more preferably 1.0 mg or more, and even more preferably 2.0 mg or more, from the viewpoint of improving bactericidal or antiviral properties, and preferably 60 mg or less, more preferably 50 mg or less, and even more preferably 45 mg or less, from the viewpoint of making it easier to suppress skin irritation even when the composition is continuously applied to the skin. Furthermore, the content of component (A1) in the composition dispensed in a single dispensing operation from a quantitative dispensing container is 0.05 mg or more and 80 mg or less, preferably 0.1 mg or more and 60 mg or less, more preferably 0.2 mg or more and 60 mg or less, even more preferably 0.4 mg or more and 50 mg or less, even more preferably 0.5 mg or more and 50 mg or less, even more preferably 1.0 mg or more and 45 mg or less, and even more preferably 2.0 mg or more and 45 mg or less. The amount of component (A1) in the composition dispensed in a single dispensing operation can be calculated by the method described in the examples.

[0018] The amount of component (A1) in the composition dispensed in a single dispensing operation can be controlled by the amount of component (A) in the composition used in the topical skin preparation of the present invention, the pH of the composition, the viscosity of the composition, the type of quantitative dispensing container, and the amount dispensed in a single dispensing operation, or a combination thereof.

[0019] In the topical skin preparation of the present invention, the amount of the composition dispensed in a single dispensing operation from the quantitative dispensing container is preferably 0.05 g or more, more preferably 0.1 g or more, and even more preferably 0.2 g or more, from the viewpoint of improving bactericidal or antiviral properties and improving applicability to the skin, and preferably 3.0 g or less, more preferably 2.5 g or less, and even more preferably 2.0 g or less, from the viewpoint of suppressing skin irritation and suppressing dripping after application to the skin. Furthermore, the amount of the composition dispensed in a single dispensing operation from the quantitative dispensing container is preferably 0.05 g or more and 3.0 g or less, more preferably 0.1 g or more and 2.5 g or less, and even more preferably 0.2 g or more and 2.0 g or less.

[0020] <Quantitative dispensing container> The topical skin preparation of the present invention comprises a topical skin preparation composition containing one or more acids or salts thereof selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid (A), which is contained in a quantitative dispensing container. In this specification, "quantitative dispensing container" means a container capable of containing a topical skin preparation composition, and capable of dispensing approximately a constant amount of the topical skin preparation composition, which is the contents of the container, by performing a dispensing operation.

[0021] Examples of quantitative dispensing containers include pressure-type containers such as stroke-type and squeeze-type containers; electric dispenser-type containers; and the like. Single-use individual packaging containers are also included in the quantitative dispensing containers of this invention. Among press-type containers, stroke-type press-type containers include pump-type and spray-type containers, and the stroke-type press-type container described in Japanese Patent Publication No. 2019-51949 can be cited as an example. Furthermore, the squeeze-type press-type container described in Japanese Patent Publication No. 2001-151283 can be cited as an example. Examples of electric dispenser containers include those equipped with a mechanism that automatically dispenses a fixed amount of contents when a hand is placed over a sensor.

[0022] In this specification, a single dispensing operation of a quantitative dispensing container is defined as follows: If the quantitative dispensing container is a stroke-type press-type container, one dispensing operation is defined as pressing the container once with a full stroke. A full stroke here means applying a load of 7 kg for 3 seconds through the stroke. If the quantitative dispensing container is a squeeze-type pressure-operated container, one dispensing operation is defined as the operation of pressing the pressure part of the container once to cause squeeze deformation. Here, squeeze deformation means the state in which a load of 7 kg is applied by pressing for 3 seconds. The pressure part of the container may differ depending on the shape of the container, but for example, it refers to the outer circumference of the side of the container. If the quantitative dispensing container is an electric dispenser, one dispensing operation is, for example, the operation of placing a hand over the sensor that controls the dispensing of the contents of the container once.

[0023] While there are no particular restrictions on the capacity of a quantitative dispensing container intended for multiple dispensings, from the viewpoint of accommodating topical skin preparation compositions, it is usually in the range of 5 mL or more and 2,000 mL or less.

[0024] <Skin topical preparation composition> The topical skin preparation composition used in the topical skin preparation of the present invention (hereinafter also referred to as the topical skin preparation composition of the present invention or the composition of the present invention) is a composition containing one or more acids or salts thereof selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid (A). The composition is contained in the quantitative dispensing container and used by dispensing it from the quantitative dispensing container.

[0025] (Component (A)) Component (A) is one or more acids or salts thereof selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid. Component (A) acts as a bactericidal or antiviral component. Examples of salts of lactic acid, pyruvic acid, and urocanic acid include alkali metal salts of lactic acid or pyruvic acid such as potassium salts and sodium salts; alkaline earth metal salts of lactic acid or pyruvic acid such as calcium salts and magnesium salts; amine salts; and ammonium salts. Among these, from the viewpoint of improving bactericidal or virucidal activity and ease of availability, one or more selected from the group consisting of alkali metal salts and alkaline earth metal salts of lactic acid, pyruvic acid, and urocanic acid are preferred, one or more selected from the group consisting of potassium salts, sodium salts, and calcium salts are more preferred, and one or more selected from the group consisting of potassium lactate, sodium lactate, and calcium lactate are even more preferred. From the viewpoint of improving bactericidal or virucidal properties, component (A) is preferably lactic acid or a salt thereof, more preferably one or more selected from the group consisting of lactic acid, potassium lactate, sodium lactate, and calcium lactate, and even more preferably contains lactic acid. If component (A) contains lactic acid, the content of lactic acid or its salt in the total amount of component (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass, from the viewpoint of improving bactericidal or antiviral properties.

[0026] From the viewpoint of improving bactericidal or antiviral properties, the content of component (A) in the composition of the present invention is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. Furthermore, from the viewpoint of suppressing skin irritation, it is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5.0% by mass or less, even more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, even more preferably 2.5% by mass or less, and even more preferably 2.0% by mass or less. Furthermore, the content of component (A) in the composition is preferably 0.05% by mass or more and 15% by mass or less, more preferably 0.05% by mass or more and 10% by mass or less, even more preferably 0.1% by mass or more and 10% by mass or less, even more preferably 0.2% by mass or more and 5.0% by mass or less, even more preferably 0.3% by mass or more and 4.0% by mass or less, even more preferably 0.5% by mass or more and 3.0% by mass or less, even more preferably 0.5% by mass or more and 2.5% by mass or less, and even more preferably 0.5% by mass or more and 2.0% by mass or less. In this specification, if component (A) contains a salt, "content of component (A)" means the sum of the amount of the acid ("component (A1) present in acid form" and "component (A2) present in dissociated form") and the amount of the salt converted to its dissociated form.

[0027] From the viewpoint of improving bactericidal or antiviral properties, the content of component (A1) in the composition of the present invention is preferably 0.02% by mass or more, more preferably 0.04% by mass or more, even more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more. Furthermore, from the viewpoint of suppressing skin irritation, it is preferably 10% by mass or less, more preferably 5.0% by mass or less, even more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, even more preferably 2.5% by mass or less, even more preferably 2.0% by mass or less, and even more preferably 1.0% by mass or less. Furthermore, the content of component (A1) in the composition of the present invention is preferably 0.02% by mass or more and 10% by mass or less, more preferably 0.04% by mass or more and 5.0% by mass or less, even more preferably 0.05% by mass or more and 4.0% by mass or less, even more preferably 0.1% by mass or more and 3.0% by mass or less, even more preferably 0.2% by mass or more and 2.5% by mass or less, even more preferably 0.3% by mass or more and 2.0% by mass or less, and even more preferably 0.3% by mass or more and 1.0% by mass or less.

[0028] The content of component (A1) in the composition of the present invention can be calculated using the following formula, where component (A1) is the acid derived from component (A) present in the composition of the present invention, and component (A2) is the acid that exists in the acid form. Content (mass%) of component (A1) in the composition = Content (mass%) of component (A) in the composition × Molar ratio in the composition [(A1) / {(A1)+(A2)}] Here, "molar ratio in the composition [(A1) / {(A1)+(A2)}]" means the molar ratio of component (A1) to the total of components (A1) and (A2) present in the composition, and can be calculated specifically by the method described in the examples of this invention. The molar ratio [(A1) / {(A1)+(A2)}] in the composition is preferably 0.2 or higher, more preferably 0.3 or higher, and even more preferably 0.4 or higher, from the viewpoint of improving bactericidal or antiviral properties. Furthermore, from the viewpoint of suppressing skin irritation, it is preferably 0.6 or lower, more preferably 0.55 or lower, and even more preferably 0.5 or lower. When the acid derived from component (A) present in the composition is considered as component (A1) if it exists in acid form and as component (A2) if it exists in dissociated form, the molar ratio [(A1) / {(A1)+(A2)}] in the composition is preferably 0.2 to 0.6, more preferably 0.3 to 0.55, and even more preferably 0.4 to 0.5.

[0029] (Ingredient (B): Nonionic thickener) From the viewpoint of improving the feel of use, the topical skin preparation composition may further contain a nonionic thickener as component (B). In this specification, "good feel of use" means that when the topical skin preparation composition is applied to the skin, dried, and then wetted with water, there is little squeaky feeling and the texture is good. The component (B) used in the composition of the present invention is preferably a water-soluble nonionic thickener from the viewpoint of improving usability, improving or maintaining bactericidal or virucidal properties, and improving solubility in the composition. Specific examples of component (B) include cellulose ethers such as hydroxybutyl methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, and hydroxyethyl cellulose; propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl guar gum, locust bean gum, amylose, hydroxyethyl amylose, starch, or derivatives thereof, and one or more of these can be used. Among the above, from the viewpoint of maintaining bactericidal or antiviral properties and improving the feel of the composition, component (B) is preferably one or more selected from the group consisting of cellulose ethers and polyvinyl alcohol, more preferably one or more selected from the group consisting of hydroxybutyl methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, and polyvinyl alcohol, even more preferably one or more selected from the group consisting of hydroxyethyl cellulose and polyvinyl alcohol, and even more preferably hydroxyethyl cellulose.

[0030] The degree of polymerization of the polyvinyl alcohol used as component (B) is preferably 500 or more, more preferably 700 or more, even more preferably 1,000 or more, even more preferably 1,500 or more, and even more preferably 2,000 or more, from the viewpoint of improving the feel of the composition, and preferably 8,000 or less, more preferably 6,000 or less, and even more preferably 5,000 or less, from the viewpoint of the dischargeability of the composition. Furthermore, the degree of polymerization of the polyvinyl alcohol is preferably 500 to 8,000, more preferably 700 to 8,000, even more preferably 1,000 to 6,000, even more preferably 1,500 to 6,000, and even more preferably 2,000 to 5,000. The saponification value of polyvinyl alcohol is not particularly limited, but from the viewpoint of improving the feel of the composition, it is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less.

[0031] As component (B), commercially available nonionic thickeners can also be used. Examples of hydroxyethylcellulose include "Natrosol HEC 250HHX" from Ashland Co., Ltd. and "HEC Daicel 850SE" from Daicel Corporation, while examples of polyvinyl alcohol include "JC-40" from Nippon Vinegar Vinegar Co., Ltd.

[0032] When component (B) is used, the content of component (B) in the composition of the present invention is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, from the viewpoint of improving the feel of the composition, and from the viewpoint of improving or maintaining the dischargeability and bactericidal or virucidal properties of the composition of the present invention, it is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.5% by mass or less. Furthermore, the content of component (B) in the composition of the present invention is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.02% by mass or more and 15% by mass or less, even more preferably 0.05% by mass or more and 15% by mass or less, even more preferably 0.1% by mass or more and 10% by mass or less, even more preferably 0.2% by mass or more and 5% by mass or less, even more preferably 0.2% by mass or more and 3% by mass or less, even more preferably 0.2% by mass or more and 1% by mass or less, and even more preferably 0.2% by mass or more and 0.5% by mass or less.

[0033] (water) The topical skin preparation composition of the present invention preferably further contains water from the viewpoint of dissolving component (A) and improving the dischargeability of the composition. The water content in the composition is preferably 40% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and also preferably 99.95% by mass or less.

[0034] The total content of component (A) and water in the topical skin preparation composition of the present invention is preferably 70.05% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, and also 100% by mass or less, from the viewpoint of obtaining the effects of the present invention, the solubility of component (A), and improving dispensability.

[0035] (Polyol) The topical skin preparation composition of the present invention may further contain a polyol, from the viewpoint of bringing the polarity of the composition closer to the polarity of the skin surface, making it easier to spread on the skin, and ensuring that the bactericidal or antiviral components are evenly exerted on the intended application surface.

[0036] Preferably, polyols with a logPow value (octanol / water partition coefficient) of -2.0 or higher can be used. A higher logPow value indicates higher hydrophobicity, and by including a predetermined amount of such polyol in the composition, it is expected that the composition will become hydrophobic and more easily absorbed by the skin than pure water. Here, Pow: The ratio of polyol concentrations in two solvent phases when a polyol is added to two solvent phases, 1-octanol and water, to reach equilibrium. logPow = log10(concentration of polyol in the 1-octanol phase / concentration of polyol in the aqueous phase) That is the case. The logPow value of a polyol can be calculated using the algorithm "XLOGP3" described in Renxiao Wang et al., J.Chem.Inf.Model.2007, Vol.47, pp.2140.

[0037] Specific examples of polyols include propylene glycol (1,2-propanediol), 1,3-propanediol, dipropylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 1,6-hexanediol, Linear diols such as 1,2-heptanediol, 1,7-heptanediol, 1,2-octanediol, 1,8-octanediol, 1,2-nonanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1,2-dodecanediol, 1,12-dodecanediol, 1,2-tetradecanediol, 1,2-hexadecanediol, and 1,16-hexadecanediol; Linear triols such as glycerin, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,7-heptanetriol, 1,2,8-octantriol, 1,2,9-nonanetriol, and 1,2,10-decanetriol; Branched-chain diols or triols such as 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2-methylpentane-2,4-diol, 2-ethyl-1,3-hexanediol, tripropylene glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-(2-ethylhexyloxy)-1,2-propanediol, (lauryl / myristyl) glycol hydroxypropyl ether, 3,7,11,15-tetramethylhexadecane-1,2,3-triol; and, Examples include polymers such as polyethylene glycol, polyglycerin, and PPG-10 butanediol; one or more of these can be used.

[0038] When the topical skin preparation composition of the present invention contains a polyol, the polyol content in the topical skin preparation composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 2.0% by mass or more, from the viewpoint of easy application to the skin and evenly exerting the bactericidal or antiviral component on the intended application surface. Furthermore, from the viewpoint of reducing stickiness during application, it is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. The polyol content in the topical skin preparation composition is preferably 0.05% by mass or more and 50% by mass or less, more preferably 0.1% by mass or more and 50% by mass or less, even more preferably 0.5% by mass or more and 30% by mass or less, even more preferably 1.0% by mass or more and 30% by mass or less, even more preferably 1.5% by mass or more and 20% by mass or less, and even more preferably 2.0% by mass or more and 20% by mass or less.

[0039] (pH adjuster) The topical skin preparation composition of the present invention preferably contains a pH adjusting agent, from the viewpoint of adjusting the pH to a suitable range. The pH adjusting agent can be any component that can adjust the pH of the composition to a desired range, such as an acid component, an alkaline component, or a buffering agent component. Among these, it is preferable to use at least an alkaline component as the pH adjusting agent, from the viewpoint of setting the pH of the composition containing component (A) at 25°C to the range described later (preferably 3.5 or higher). As the alkaline component, either an organic alkaline agent or an inorganic alkaline agent can be used, but from the viewpoint of solubility in water, availability, and cost-effectiveness, an inorganic alkaline agent is preferred. Examples of inorganic alkaline agents include metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide, and metal carbonates such as sodium carbonate and sodium bicarbonate. One or more of these can be used. Among these, from the viewpoint of availability and economic efficiency, it is preferable to use one or more selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides, more preferably alkali metal hydroxides, even more preferably one or more selected from the group consisting of sodium hydroxide and potassium hydroxide, and even more preferably sodium hydroxide. If a topical skin preparation composition contains a pH adjuster, the amount of the pH adjuster in the composition should be such that it can adjust the pH of the composition to the desired range.

[0040] (Metal ion concentration) In the present invention, from the viewpoint of increasing the content of component (A1) in the topical skin preparation composition of the present invention, it is preferable to increase the content of component (A) in the topical skin preparation composition of the present invention. Furthermore, even when the content of component (A) in the topical skin preparation composition is increased, from the viewpoint of controlling the pH within the desired range, one or more selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides are preferably used in the topical skin preparation composition. The alkali metal hydroxides and alkaline earth metal hydroxides are as described above. As a result of using one or more selected from the group consisting of alkali metal hydroxides and alkaline earth metal hydroxides, the metal ion concentration in the topical skin preparation composition is preferably 0.002 mol / L or higher, more preferably 0.005 mol / L or higher, even more preferably 0.01 mol / L or higher, and even more preferably 0.02 mol / L or higher. On the other hand, from the viewpoint of maintaining the mineral balance of the skin, the metal ion concentration in the topical skin preparation composition is preferably 0.80 mol / L or lower, more preferably 0.50 mol / L or lower, even more preferably 0.30 mol / L or lower, and even more preferably 0.20 mol / L or lower. Furthermore, the metal ion concentration in the topical skin preparation composition is preferably 0.002 mol / L or more and 0.80 mol / L or less, more preferably 0.002 mol / L or more and 0.50 mol / L or less, even more preferably 0.005 mol / L or more and 0.50 mol / L or less, even more preferably 0.01 mol / L or more and 0.30 mol / L or less, and even more preferably 0.02 mol / L or more and 0.20 mol / L or less.

[0041] In this specification, "concentration of metal ions in a topical skin preparation composition" means the total concentration of metal ions present in the composition. In the composition used in the present invention, this is mainly the sum of the concentrations of metal ions derived from a predetermined organic acid salt contained in component (A) and metal ions derived from the pH adjusting agent. Generally, the presence of metal ions in a composition tends to inhibit the bactericidal effect of disinfectants such as benzalkonium chloride. However, in the topical skin preparation composition used in the present invention, the bactericidal or virucidal properties of component (A) are not inhibited by metal ions, and therefore excellent bactericidal or virucidal properties can be exhibited. The concentration of metal ions in the composition can be measured by the ion-selective electrode method.

[0042] (Other ingredients) In addition to the above, the topical skin preparation composition of the present invention may also contain other components as needed, such as surfactants, UV absorbers, antioxidants, preservatives, antiperspirants, fragrances, moisturizers, texture modifiers, anti-inflammatory agents, etc.

[0043] From the viewpoint that the topical skin preparation composition of the present invention is a composition that uses component (A) as a bactericidal or antiviral component, it can exhibit bactericidal or antiviral properties even without incorporating monoalcohols having 4 or fewer carbon atoms, such as ethanol or isopropanol. Furthermore, from the viewpoint of suppressing skin irritation, the content of monoalcohols having 4 or fewer carbon atoms in the composition is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 10% by mass or less, even more preferably 5.0% by mass or less, even more preferably 1.0% by mass or less, even more preferably 0.05% by mass or less, even more preferably less than 0.01% by mass, and most preferably substantially 0% by mass.

[0044] (Component (C): Organic acids or salts thereof other than component (A)) From the viewpoint that the topical skin preparation composition is a composition using component (A) as a bactericidal or antiviral component, it can exhibit bactericidal or antiviral properties even without the inclusion of organic acids or salts thereof other than component (A) (hereinafter also referred to as "component (C)"). From this viewpoint, and from the viewpoint of suppressing skin irritation, the content of organic acids or salts thereof (C) other than component (A) in the composition is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, even more preferably less than 0.5% by mass, and even more preferably less than 0.1% by mass, and most preferably substantially 0% by mass. In this specification, if component (C) is an organic acid salt, "content of component (C)" refers to the amount converted to the equivalent amount of the organic acid.

[0045] Furthermore, the mass ratio of organic acids other than component (A) or their salts (C) (C) to component (A) in the topical skin preparation composition [(C) / (A)] is preferably less than 1, more preferably 0.8 or less, even more preferably 0.6 or less, even more preferably 0.5 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, even more preferably 0.1 or less, even more preferably 0.05 or less, even more preferably 0.01 or less, and even more preferably substantially 0.

[0046] In addition, organic acids other than component (A) that correspond to component (C) or their salts include carboxylic acid compounds other than component (A), sulfonic acid compounds, or salts thereof. Examples of the carboxylic acid compounds or salts thereof include aliphatic monocarboxylic acids having 4 or fewer carbon atoms, such as acetic acid, propionic acid, and butanoic acid; aromatic monocarboxylic acids such as benzoic acid; aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and fumaric acid; aromatic dicarboxylic acids such as phthalic acid and isophthalic acid; polycarboxylic acids such as polyglutamic acid; hydroxycarboxylic acids such as malic acid, glycolic acid, hydroxyacrylic acid, glyceric acid, tartaric acid, and citric acid; acidic amino acids such as glutamic acid and aspartic acid; pyrrolidone carboxylic acids; or salts thereof. Examples of the above-mentioned sulfonic acid compounds or their salts include aliphatic sulfonic acids such as methanesulfonic acid and ethanesulfonic acid; aromatic sulfonic acids such as p-toluenesulfonic acid and naphthalenesulfonic acid; and salts thereof. Examples of salts of the above-mentioned organic acids include alkali metal salts such as potassium salts and sodium salts; alkaline earth metal salts such as calcium salts and magnesium salts; amine salts; and ammonium salts.

[0047] The topical skin preparation composition, in terms of being a composition using component (A) as a bactericidal or antiviral component, exhibits bactericidal or antiviral properties even without the inclusion of bactericidal agents such as quaternary ammonium salts like benzalkonium chloride and benzethonium chloride; amphoteric surfactants like alkyldiaminoethylglycine chloride and alkylpolyaminoethylglycine; biguanides like chlorhexidine gluconate; sodium hypochlorite; aldehydes like glutaraldehyde, phthalaldehyde, and formalin; povidone-iodine; iodine tincture; phenol; cresol soap solution; peracetic acid; and hydrogen peroxide. From this viewpoint, and from the viewpoint of suppressing skin irritation, the bactericide content in the composition is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.07% by mass or less, even more preferably 0.05% by mass or less, even more preferably 0.03% by mass or less, even more preferably less than 0.01% by mass, and most preferably substantially 0% by mass. On the other hand, when the above bactericide is included, from the viewpoint of improving bactericidal or antiviral properties, the bactericide content in the composition is preferably 0.01% by mass or more, even more preferably 0.05% by mass or more. Furthermore, from the viewpoint of suppressing skin irritation, the mass ratio of the disinfectant to component (A) (disinfectant / component (A)) is preferably 0.5 or less, more preferably 0.2 or less, even more preferably 0.1 or less, even more preferably 0.05 or less, even more preferably 0.03 or less, and even more preferably 0.01 or less, and most preferably substantially 0. On the other hand, when the disinfectant is included, from the viewpoint of improving bactericidal or antiviral activity, the mass ratio of the disinfectant to component (A) (disinfectant / component (A)) is preferably 0.01 or more, and more preferably 0.05 or more. In this specification, an agent that is a disinfectant and also acts as a surfactant is defined as a disinfectant.

[0048] (viscosity) The viscosity of the topical skin preparation composition at 25°C is preferably 1.0 mPa·s or higher, more preferably 2.0 mPa·s or higher, and even more preferably 3.0 mPa·s or higher, from the viewpoint of homogenizing the amount dispensed per dispensing operation of a quantitative dispensing container and improving applicability to the skin. From the viewpoint of improving dispensability by a quantitative dispensing container and improving or maintaining bactericidal or antiviral properties, it is preferably 30,000 mPa·s or lower, more preferably 25,000 mPa·s or lower, even more preferably 10,000 mPa·s or lower, even more preferably 8,000 mPa·s or lower, even more preferably 6,500 mPa·s or lower, even more preferably 5,000 mPa·s or lower, even more preferably 2,000 mPa·s or lower, even more preferably 1,000 mPa·s or lower, and even more preferably 700 mPa·s or lower. The lower the viscosity of a topical skin preparation composition, the more difficult it becomes to control the amount supplied to the skin. However, the topical skin preparation of the present invention has the advantage of being able to dispense a constant amount and supply it to the skin even if the composition has low viscosity. When the quantitative dispensing container containing the composition is a stroke-type and pump-type pressure-type container, the viscosity of the composition at 25°C is more preferably 10,000 mPa·s or less, more preferably 8,000 mPa·s or less, more preferably 6,500 mPa·s or less, more preferably 5,000 mPa·s or less, more preferably 2,000 mPa·s or less, more preferably 1,000 mPa·s or less, and more preferably 700 mPa·s or less, from the viewpoint of improving dispensability and ease of spreading during application. Furthermore, from the viewpoint of preventing dripping during dispensing and reducing spillage during application, it may be 5.0 mPa·s or more, and even more preferably 100 mPa·s or more. When the quantitative dispensing container containing the composition is a stroke-type and spray-type press-type container, the viscosity of the composition at 25°C is more preferably 1,000 mPa·s or less, more preferably 800 mPa·s or less, more preferably 500 mPa·s or less, more preferably 300 mPa·s or less, more preferably 200 mPa·s or less, and more preferably 100 mPa·s or less, from the viewpoint of improving dispensing performance and ease of spreading during application. Furthermore, from the viewpoint of preventing dripping during dispensing and reducing spillage during application, it may be 5.0 mPa·s or more, and even more preferably 10.0 mPa·s or more.

[0049] If the quantitative dispensing container containing the composition is a squeeze-type press-type container, the viscosity of the composition at 25°C is, from the viewpoint of quantitative dispensing, more preferably 25,000 mPa·s or less, more preferably 10,000 mPa·s or less, more preferably 8,000 mPa·s or less, more preferably 6,500 mPa·s or less, and more preferably 2,000 mPa·s or less, and from the same viewpoint, more preferably 100 mPa·s or more, and more preferably 500 mPa·s or more. When the quantitative dispensing container containing the composition is an electrically operated dispenser type container, the viscosity of the composition at 25°C is, from the viewpoint of dispensing performance, more preferably 1,000 mPa·s or less, more preferably 800 mPa·s or less, more preferably 500 mPa·s or less, more preferably 300 mPa·s or less, more preferably 200 mPa·s or less, and more preferably 100 mPa·s or less. Furthermore, from the viewpoint of preventing dripping during dispensing and reducing spillage during application, it may be 5.0 mPa·s or more, and even more preferably 10.0 mPa·s or more. The viscosity of the composition at 25°C can be measured specifically by the method described in the examples.

[0050] (pH) The topical skin preparation composition has a pH of 3.5 or higher, more preferably 3.7 or higher, at 25°C, from the viewpoint of adjusting the content ratio of component (A1) in the composition of the present invention and from the viewpoint of suppressing skin irritation. Furthermore, from the viewpoint of improving bactericidal or antiviral properties, it is preferably 5.0 or lower, more preferably 4.5 or lower. In addition, the pH of the topical skin preparation composition at 25°C is preferably 3.5 or higher and 5.0 or lower, more preferably 3.5 or higher and 4.5 or lower, and even more preferably 3.7 or higher and 4.5 or lower. The pH of the composition at 25°C can be measured specifically by the method described in the examples.

[0051] <Form of topical skin preparation composition> The topical skin preparation composition used in the present invention only needs to be fluid at 25°C. Its form is not particularly limited; for example, it can be liquid, gel, cream, or foam. A liquid form is preferable from the viewpoint of easy application to the skin and ensuring even distribution of the bactericidal or antiviral component on the intended application surface. Furthermore, a gel, cream, or foam form is preferable from the viewpoint of preventing dripping from the skin and supplying the intended amount of component (A1) to the skin. Furthermore, the composition may be in the form of an emulsion, and the emulsion may be either an oil-in-water emulsion or an oil-in-water emulsion. From the viewpoint of being easy to spread on the skin and evenly exerting the bactericidal or antiviral component on the intended application surface, an oil-in-water emulsion is preferred. Also, from the viewpoint of preventing dripping from the skin when applied and supplying the component (A1) in the intended amount, an oil-in-water emulsion is preferred.

[0052] The topical skin preparation of the present invention is more preferably in the form of (I) or (II) below. (I) A topical skin preparation composition contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). In a topical skin preparation in which, when the acid present in the composition is defined as component (A1), the amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less, The above component (A) is lactic acid or a salt thereof, In the composition, the mass ratio of an organic acid other than component (A) or its salt (C) to component (A) [(C) / (A)] is less than 1. A topical skin preparation having a pH of 3.5 or higher and 5.0 or lower at 25°C. (II) A topical skin preparation composition contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). In a topical skin preparation in which, when the acid present in the composition is defined as component (A1), the amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less, The composition further contains a nonionic thickener (B), A topical skin preparation having a viscosity of 100 mPa·s or more and 10,000 mPa·s or less at 25°C.

[0053] The topical skin preparation according to embodiment (I) above exhibits a remarkable bactericidal or antiviral effect due to having the above configuration. In the topical skin preparation composition used in the embodiment of (I) above, the mass ratio of an organic acid other than component (A) or its salt (C) (C) to component (A) [(C) / (A)] is less than 1, preferably 0.8 or less, more preferably 0.6 or less, even more preferably 0.5 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, even more preferably 0.1 or less, even more preferably 0.05 or less, even more preferably 0.01 or less, and even more preferably substantially 0. The pH at 25°C of the topical skin preparation composition used in the topical skin preparation according to embodiment (I) above is 3.5 or more and 5.0 or less, preferably 3.5 or more and 4.5 or less, and more preferably 3.7 or more and 4.5 or less. Other requirements and their preferred scope are the same as described above.

[0054] The topical skin preparation according to embodiment (II) above, having the above configuration, can achieve both bactericidal or antiviral properties and a better user experience. The viscosity at 25°C of the topical skin preparation composition used in the aspect of (II) described above is 100 mPa·s or more and 10,000 mPa·s or less, preferably 100 mPa·s or more and 5,000 mPa·s or less, more preferably 100 mPa·s or more and 8,000 mPa·s or less, even more preferably 100 mPa·s or more and 2,000 mPa·s or less, even more preferably 100 mPa·s or more and 1,000 mPa·s or less, even more preferably 100 mPa·s or more and 800 mPa·s or less, and even more preferably 100 mPa·s or more and 700 mPa·s or less, from the viewpoint of maintaining bactericidal or antiviral properties and improving usability. Other requirements and their preferred scope are the same as described above.

[0055] <Form of topical skin preparation> The topical skin preparation of the present invention exhibits bactericidal or antiviral properties on the skin surface by leaving component (A), which is a bactericidal or antiviral component contained in the dispensed composition, on the skin surface. From the viewpoint of obtaining this effect, the topical skin preparation of the present invention is preferably a leave-on topical skin preparation. That is, when using the topical skin preparation of the present invention, the composition dispensed from the quantitative dispensing container is applied to the skin by application or the like, and then the composition is not removed by washing with water or the like, but is left on the skin surface for use. From the viewpoint of preventing contact infection by bacteria or viruses, the skin topical preparation of the present invention is more preferably a leave-on skin topical preparation for the hands.

[0056] <Bacteria or viruses that exhibit bactericidal or virticidal properties> The bacteria or viruses that the topical skin preparation of the present invention is intended to bactericidate or antiviral are not particularly limited as long as they are inactivated or killed by contact with acid. For example, it is considered that microorganisms listed in the Ministry of Health, Labour and Welfare's guidelines for infectious disease control in childcare facilities can be used. Specifically, examples of bacteria include Gram-positive bacteria such as Bacillus anthrax, Mycobacterium tuberculosis, Streptococcus lyticus, Staphylococcus aureus, and Streptococcus pneumoniae, or Gram-negative bacteria such as Bacillus tularensis, Plague bacillus, Brucella, Glanders, Vibrio cholerae, Salmonella, Shigella, enterohemorrhagic Escherichia coli, and Bordetella pertussis. Examples of viruses include enveloped viruses such as arenavirus, Ebola virus, smallpox virus, nairovirus, Marburg virus, coronavirus, monkeypox virus, beta-coronavirus, influenza virus, RSV, herpesvirus, mumps virus, varicella-zoster virus, rubella virus, and measles virus, as well as non-enveloped viruses such as enterovirus, adenovirus, coxsackievirus, norovirus, and rotavirus. In this example, the bactericidal and virucidal properties are evaluated using Serratia bacteria as an example, but the bacteria or viruses targeted by this invention are not limited to these.

[0057] [Method for supplying ingredient (A) to the application site on the skin surface] The present invention also provides a method for supplying one or more acids or salts thereof (A) selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid to an application site on the skin surface, the method comprising the following steps (I) and (II) in order (hereinafter also simply referred to as "the method of the present invention"). Step (I): A step of cleaning the application area. Step (II): A step of supplying the composition containing component (A) to the application site by discharging the composition from a quantitative discharging container containing the composition in a single discharging operation, wherein, when the acid present in the composition is in acid form (A1), the content of component (A1) in the composition discharged from the quantitative discharging container in a single discharging operation is 0.05 mg or more and 80 mg or less.

[0058] According to the method of the present invention, excellent bactericidal or antiviral properties can be exhibited on the skin surface, and skin irritation can be suppressed. The component (A), the composition containing the component (A), the quantitative dispensing container, and preferred embodiments thereof are the same as described above.

[0059] In step (I), the application area on the skin surface is cleansed beforehand using water, soap, body wash, hand soap, etc. Since the skin after cleansing has had naturally present components such as lactic acid washed away, and its ability to defend against bacteria and viruses in the external environment is reduced, it is preferable to apply the composition in step (II) after performing step (I) and carry out the method of the present invention.

[0060] After cleaning in step (I), the application area on the skin surface can be dried by air drying or other means before proceeding to step (II).

[0061] In step (II), the composition containing component (A) is dispensed onto the application site of the skin surface that was cleaned in step (I). The amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more, preferably 0.1 mg or more, more preferably 0.2 mg or more, even more preferably 0.4 mg or more, even more preferably 0.5 mg or more, even more preferably 1.0 mg or more, and even more preferably 2.0 mg or more, and 80 mg or less, preferably 60 mg or less, more preferably 50 mg or less, and even more preferably 45 mg or less, from the viewpoint of suppressing skin irritation. Furthermore, the content of component (A1) in the composition discharged in a single discharge operation from the quantitative discharge container is 0.05 mg or more and 80 mg or less, preferably 0.1 mg or more and 60 mg or less, more preferably 0.2 mg or more and 60 mg or less, even more preferably 0.4 mg or more and 50 mg or less, even more preferably 0.5 mg or more and 50 mg or less, even more preferably 1.0 mg or more and 45 mg or less, and even more preferably 2.0 mg or more and 45 mg or less. The amount of component (A1) in the composition dispensed in a single dispensing operation can be determined by the same method as described above.

[0062] After supplying the composition to the skin in step (II), it is preferable not to remove the composition by washing with water or the like, but to leave it on the skin surface. This is because by using the composition as a leave-on formulation, the bactericidal or antiviral component (A) can be left on the skin surface, thereby imparting bactericidal or antiviral properties to the skin surface.

[0063] With regard to the embodiments described above, the present invention further discloses the following. <1> A topical skin preparation composition is contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). A topical skin preparation in which, when the acid present in the composition is defined as component (A1), the amount of component (A1) dispensed from the quantitative dispensing container in a single dispensing operation is 0.05 mg or more and 80 mg or less. <2> The content of component (A1) in the composition discharged in a single discharge operation from the quantitative discharge container is preferably 0.1 mg to 60 mg, more preferably 0.2 mg to 60 mg, even more preferably 0.4 mg to 50 mg, even more preferably 0.5 mg to 50 mg, even more preferably 1.0 mg to 45 mg, and even more preferably 2.0 mg to 45 mg. <1> Topical skin preparations as described above. <3> The amount of the composition dispensed from the quantitative dispensing container in a single dispensing operation is preferably 0.05 g or more and 3.0 g or less, more preferably 0.1 g or more and 2.5 g or less, and even more preferably 0.2 g or more and 2.0 g or less. <1> or <2> Topical skin preparations as described above. <4> The aforementioned component (A) contains lactic acid or a salt thereof, preferably one or more selected from the group consisting of lactic acid, potassium lactate, sodium lactate, and calcium lactate, more preferably lactic acid. <1> ~ <3> A topical skin preparation as described in any one of the following: <5> The aforementioned component (A) contains lactic acid, and the content of lactic acid or its salt in the total amount of component (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass. <1> ~ <4> A topical skin preparation as described in any one of the following: <6> The content of component (A) in the composition is preferably 0.05% by mass or more and 15% by mass or less, more preferably 0.05% by mass or more and 10% by mass or less, even more preferably 0.1% by mass or more and 10% by mass or less, even more preferably 0.2% by mass or more and 5.0% by mass or less, even more preferably 0.3% by mass or more and 4.0% by mass or less, even more preferably 0.5% by mass or more and 3.0% by mass or less, even more preferably 0.5% by mass or more and 2.5% by mass or less, and even more preferably 0.5% by mass or more and 2.0% by mass or less. <1> ~ <5> A topical skin preparation as described in any one of the following: <7> The content of component (A1) in the composition is preferably 0.02% by mass or more and 10% by mass or less, more preferably 0.04% by mass or more and 5.0% by mass or less, even more preferably 0.05% by mass or more and 4.0% by mass or less, even more preferably 0.1% by mass or more and 3.0% by mass or less, even more preferably 0.2% by mass or more and 2.5% by mass or less, even more preferably 0.3% by mass or more and 2.0% by mass or less, and even more preferably 0.3% by mass or more and 1.0% by mass or less. <1> ~ <6> A topical skin preparation as described in any one of the following: <8> When the acid derived from component (A) present in the composition is defined as component (A1) if it exists in acid form and component (A2) if it exists in dissociated form, the molar ratio [(A1) / {(A1)+(A2)}] in the composition is preferably 0.2 or more and 0.6 or less, more preferably 0.3 or more and 0.55 or less, and even more preferably 0.4 or more and 0.5 or less. <1> ~ <7> A topical skin preparation as described in any one of the following: <9> The composition further contains a nonionic thickener as component (B). <1> ~ <8> A topical skin preparation as described in any one of the following: <10> The aforementioned component (B) is a water-soluble nonionic thickener, preferably one or more selected from the group consisting of cellulose ethers, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl guar gum, locust bean gum, amylose, hydroxyethyl amylose, starch, or derivatives thereof; more preferably one or more selected from the group consisting of cellulose ethers and polyvinyl alcohol; even more preferably one or more selected from the group consisting of hydroxybutyl methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl cellulose, and polyvinyl alcohol; even more preferably one or more selected from the group consisting of hydroxyethyl cellulose and polyvinyl alcohol; and even more preferably hydroxyethyl cellulose. <9> Topical skin preparations as described above. <11> The degree of polymerization of the polyvinyl alcohol is preferably 500 to 8,000, more preferably 700 to 8,000, even more preferably 1,000 to 6,000, even more preferably 1,500 to 6,000, and even more preferably 2,000 to 5,000. <10> Topical skin preparations as described above. <12> The saponification value of the polyvinyl alcohol is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less. <10> or <11> Topical skin preparations as described above. <13> The content of component (B) in the composition is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.02% by mass or more and 15% by mass or less, even more preferably 0.05% by mass or more and 15% by mass or less, even more preferably 0.1% by mass or more and 10% by mass or less, even more preferably 0.2% by mass or more and 5% by mass or less, even more preferably 0.2% by mass or more and 3% by mass or less, even more preferably 0.2% by mass or more and 1% by mass or less, and even more preferably 0.2% by mass or more and 0.5% by mass or less. <9> ~ <12> A topical skin preparation as described in any one of the following: <14> The composition further contains water, the water content of which is preferably 40% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and also preferably 99.95% by mass or less. <1> ~ <13> A topical skin preparation as described in any one of the following: <15> The total content of component (A) and water in the composition is preferably 70.05% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, and also 100% by mass or less. <1> ~ <14> A topical skin preparation as described in any one of the following:

[0064] <16> The composition further contains a polyol. <1> ~ <15> A topical skin preparation as described in any one of the following: <17> The polyol satisfies the condition that the logPow value, which is the octanol / water partition coefficient, is -2.0 or greater. <16> Topical skin preparations as described above. <18> The polyols include propylene glycol (1,2-propanediol), 1,3-propanediol, dipropylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,2-heptanediol, and 1 ,7-heptanediol, 1,2-octanediol, 1,8-octanediol, 1,2-nonanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1,2-dodecanediol, 1,12-dodecanediol, 1,2-tetradecanediol, 1,2-hexadecanediol, 1,16-hexadecanediol, glycerin, 1,2,3-butanetriol, 1,2,4-butanetriol 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,7-heptanetriol, 1,2,8-octantriol, 1,2,9-nonanetriol, 1,2,10-decanetriol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,3-butanediol, 2-methylpentane-2,4-diol, 2-ethyl-1,3-hexanediol One or more selected from the group consisting of ol, tripropylene glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-(2-ethylhexyloxy)-1,2-propanediol, (lauryl / myristyl) glycol hydroxypropyl ether, 3,7,11,15-tetramethylhexadecane-1,2,3-triol, polyethylene glycol, polyglycerin, and PPG-10 butanediol. <16> or <17> Topical skin preparations as described above. <19> The polyol content in the composition is preferably 0.05% by mass or more and 50% by mass or less, more preferably 0.1% by mass or more and 50% by mass or less, even more preferably 0.5% by mass or more and 30% by mass or less, even more preferably 1.0% by mass or more and 30% by mass or less, even more preferably 1.5% by mass or more and 20% by mass or less, and even more preferably 2.0% by mass or more and 20% by mass or less. <16> ~ <18> A topical skin preparation as described in any one of the following: <20> The composition contains one or more pH adjusters, preferably inorganic alkaline agents, more preferably alkali metal hydroxides and alkaline earth metal hydroxides, even more preferably alkali metal hydroxides, even more preferably one or more selected from the group consisting of sodium hydroxide and potassium hydroxide, and even more preferably sodium hydroxide. <1> ~ <19> A topical skin preparation as described in any one of the following: <21> The metal ion concentration in the composition is preferably 0.002 mol / L or more and 0.80 mol / L or less, more preferably 0.002 mol / L or more and 0.50 mol / L or less, even more preferably 0.005 mol / L or more and 0.50 mol / L or less, even more preferably 0.01 mol / L or more and 0.30 mol / L or less, and even more preferably 0.02 mol / L or more and 0.20 mol / L or less. <1> ~ <20> A topical skin preparation as described in any one of the following: <22> The content of monoalcohols having 4 or fewer carbon atoms in the composition is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 10% by mass or less, even more preferably 5.0% by mass or less, even more preferably 1.0% by mass or less, even more preferably 0.05% by mass or less, even more preferably less than 0.01% by mass, and most preferably substantially 0% by mass. <1> ~ <21> A topical skin preparation as described in any one of the following: <23> The content of organic acids or their salts (C) other than component (A) in the composition is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, even more preferably less than 0.5% by mass, even more preferably less than 0.1% by mass, and most preferably substantially 0% by mass. <1> ~ <22> A topical skin preparation as described in any one of the following: <24> In the composition, the mass ratio of an organic acid other than component (A) or its salt (C) to component (A) [(C) / (A)] is preferably less than 1, more preferably 0.8 or less, even more preferably 0.6 or less, even more preferably 0.5 or less, even more preferably 0.3 or less, even more preferably 0.2 or less, even more preferably 0.1 or less, even more preferably 0.05 or less, even more preferably 0.01 or less, and even more preferably substantially 0. <23> Topical skin preparations as described above. <25> The bactericidal agent content in the composition is preferably 15% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 1% by mass or less, even more preferably 0.07% by mass or less, even more preferably 0.05% by mass or less, even more preferably 0.03% by mass or less, even more preferably less than 0.01% by mass, and most preferably substantially 0% by mass. <1> ~ <24> A topical skin preparation as described in any one of the following: <26> The composition contains a bactericide, and the bactericide content in the composition is preferably 0.01% by mass or more, and more preferably 0.05% by mass or more. <1> ~ <25> A topical skin preparation as described in any one of the following:

[0065] <27> The viscosity of the composition at 25°C is preferably 1.0 mPa·s or more, more preferably 2.0 mPa·s or more, even more preferably 3.0 mPa·s or more, preferably 30,000 mPa·s or less, more preferably 25,000 mPa·s or less, even more preferably 10,000 mPa·s or less, even more preferably 8,000 mPa·s or less, even more preferably 6,500 mPa·s or less, even more preferably 5,000 mPa·s or less, even more preferably 2,000 mPa·s or less, even more preferably 1,000 mPa·s or less, and even more preferably 700 mPa·s or less. <1> ~ <26> A topical skin preparation as described in any one of the following: <28> The quantitative dispensing container for containing the composition is a stroke-type and pump-type press-type container, and the viscosity of the composition at 25°C is more preferably 5.0 mPa·s or more, and more preferably 100 mPa·s or more. <27> Topical skin preparations as described above. <29> The quantitative dispensing container for containing the composition is a stroke-type and spray-type press-type container, and the viscosity of the composition at 25°C is more preferably 800 mPa·s or less, more preferably 500 mPa·s or less, more preferably 300 mPa·s or less, more preferably 200 mPa·s or less, more preferably 100 mPa·s or less, more preferably 5.0 mPa·s or more, and more preferably 10.0 mPa·s or more. <27> Topical skin preparations as described above. <30> The quantitative dispensing container for containing the composition is a squeeze-type press-type container, and the viscosity of the composition at 25°C is more preferably 25,000 mPa·s or less, more preferably 10,000 mPa·s or less, more preferably 8,000 mPa·s or less, more preferably 6,500 mPa·s or less, more preferably 2,000 mPa·s or less, more preferably 100 mPa·s or more, and more preferably 500 mPa·s or more. <27> Topical skin preparations as described above. <31> The quantitative dispensing container for containing the composition is an electric dispenser type container, and the viscosity of the composition at 25°C is more preferably 800 mPa·s or less, more preferably 500 mPa·s or less, more preferably 300 mPa·s or less, more preferably 200 mPa·s or less, more preferably 100 mPa·s or less, more preferably 5.0 mPa·s or more, and more preferably 10.0 mPa·s or more. <27> Topical skin preparations as described above. <32> The pH of the composition at 25°C is preferably 3.5 or more and 5.0 or less, more preferably 3.5 or more and 4.5 or less, and even more preferably 3.7 or more and 4.5 or less. <1> ~ <31> A topical skin preparation as described in any one of the following: <33> The following is the form (I) or (II): <1> ~ <32> A topical skin preparation as described in any one of the following: (I) A topical skin preparation composition contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). In a topical skin preparation in which, when the acid present in the composition is defined as component (A1), the amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less, The above component (A) is lactic acid or a salt thereof, In the composition, the mass ratio of an organic acid other than component (A) or its salt (C) to component (A) [(C) / (A)] is less than 1. A topical skin preparation having a pH of 3.5 or higher and 5.0 or lower at 25°C. (II) A topical skin preparation composition contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). In a topical skin preparation in which, when the acid present in the composition is defined as component (A1), the amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less, The composition further contains a nonionic thickener (B), A topical skin preparation having a viscosity of 100 mPa·s or more and 10,000 mPa·s or less at 25°C. <34> The viscosity at 25°C of the topical skin preparation composition used in the aspect of (II) described above is preferably 100 mPa·s or more and 5,000 mPa·s or less, more preferably 100 mPa·s or more and 8,000 mPa·s or less, even more preferably 100 mPa·s or more and 2,000 mPa·s or less, even more preferably 100 mPa·s or more and 1,000 mPa·s or less, even more preferably 100 mPa·s or more and 800 mPa·s or less, and even more preferably 100 mPa·s or more and 700 mPa·s or less. <33> Topical skin preparations as described above. <35> The composition is liquid, gel, cream, or foam. <1> ~ <34> A topical skin preparation as described in any one of the following: <36> The aforementioned topical skin preparation is a leave-on topical skin preparation, preferably a leave-on topical skin preparation for the hands. <1> ~ <35> A topical skin preparation as described in any one of the following: <37> A topical skin product comprising a skin topical preparation composition contained in a quantitative dispensing container, The composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid, or a salt thereof (A). A topical skin product wherein, when the acid present in the composition is defined as component (A1), the amount of component (A1) in the composition dispensed in a single dispensing operation from the quantitative dispensing container is 0.05 mg or more and 80 mg or less. <38> A method for supplying one or more acids or salts thereof (A) selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid to an application site on the skin surface, comprising the following steps (I) and (II) in order. Step (I): A step of cleaning the application area. Step (II): A step of supplying the composition containing component (A) to the application site by discharging the composition from a quantitative discharging container containing the composition in a single discharging operation, wherein, when the acid present in the composition is in acid form (A1), the content of component (A1) in the composition discharged from the quantitative discharging container in a single discharging operation is 0.05 mg or more and 80 mg or less. [Examples]

[0066] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of these examples. In these examples, various measurements and evaluations were performed by the following methods.

[0067] (Sodium ion concentration) The sodium ion concentration of the topical skin preparation composition was calculated from the amount of pH adjusting agent (1 mol / L sodium hydroxide aqueous solution) used. It should be assumed that the only metal ions contained in the compositions of this example and the comparative example are sodium ions.

[0068] (viscosity) The viscosity of the topical skin preparation composition was measured three times at 25°C using a vibrating viscometer (VM-10AL, manufactured by Sekonic Corporation), and the average value was used. The measurement conditions, depending on the viscosity of the target, are as follows: ·Viscosity: 1~100mPa·s Jig M1, rotation speed 60 rpm ·Viscosity over 100mPa·s and below 1,000mPa·s Jig M2, rotation speed 30 rpm ·Viscosity over 1,000mPa·s and below 10,000mPa·s Jig M3, rotation speed 12 rpm ·Viscosity over 10,000mPa·s and below 100,000mPa·s Jig M4, rotation speed 6 rpm

[0069] (pH) The pH of the topical skin preparation composition was measured at 25°C using an electrode 6367-10D (manufactured by Horiba, Ltd.).

[0070] (Content of component (A1) in the topical skin preparation composition) The content (mass%) of component (A1) in a topical skin preparation composition can be calculated using the following formula, where component (A1) is defined as the acidic form of the acid derived from component (A) present in the composition, and component (A2) is defined as the dissociated form. Content (mass%) of component (A1) in the skin topical preparation composition = Content (mass%) of component (A) in the composition × {Molar ratio in the composition [(A1) / {(A1)+(A2)]} Furthermore, the amount (mg) of component (A1) in the discharged composition can be calculated using the following formula. The amount of component (A1) in the discharged composition (mg) = Mass of composition (g) × 1000 × Amount of component (A) in the composition (mass%) × {Molar ratio in the composition [(A1) / {(A1)+(A2)]} ÷ 100}

[0071] Here, the "molar ratio in the composition [(A1) / {(A1)+(A2)]" is determined by the following calculation. In the following description, the molar amount of component (A1) is "HA", and the molar amount of component (A2) is "A - It is written as "". pH = pKa + log(A) - / HA) log( A - / HA) = pH - pKa A - / HA=10^(pH-pKa) A - = 10^(pH-pKa) × HA From the above, the molar ratio [(A1) / {(A1)+(A2)] is HA / (HA+A - ) = HA / (HA + 10^(pH - pKa) × HA) = 1 / (1 + 10^(pH - pKa)) Here, when lactic acid is used as component (A) (pKa = 3.86), Molar ratio [lactic acid / (lactic acid + lactate ion)] = 1 / (1 + 10^(x - 3.86)) (x represents the pH of the composition or the pH of the skin surface.)

[0072] When component (A) consists of a plurality of components, the following calculation method is defined in the present invention. Measure the pH of the composition by the method described above, substitute the pKa of each of the plurality of components into the above calculation formula, and obtain the molar ratio [(A1) / {(A1)+(A2)}] for each component. Next, by adding up the molar ratios [(A1) / {(A1)+(A2)}] for each component, the molar ratio [(A1) / {(A1)+(A2)}] when using a plurality of types of component (A) can be obtained.

[0073] Examples 1 to 12, Comparative Examples 1 to 8 (Preparation and evaluation of skin external preparation compositions) Mix each component in the amounts shown in Tables 1 to 2, and after mixing at room temperature, adjust the pH to the pH described in each table using a 1 mol / L hydrochloric acid aqueous solution and / or a 1 mol / L sodium hydroxide aqueous solution as a pH adjuster to prepare a skin external preparation composition. The amounts shown in Tables 1 to 2 are the amounts of the active ingredients (mass %) of each component. After accommodating this skin external preparation composition in a quantitative discharge container, discharge it in the amounts shown in Tables 1 and 2, and conduct the following model experiment. Specifically, using a pipetteman (manufactured by Gilson), apply an amount corresponding to the condition of spreading the compositions shown in Tables 1 and 2 over the entire palms of both hands onto the skin surface by the method described later, and evaluate the in vivo bactericidal property and skin irritation. Note that the "amount corresponding to the condition of spreading over the entire palms of both hands" refers to the amount obtained by dividing the amount (g) of the discharged composition by the average area of the palms of both hands, which is 500 cm 2 The value of the average area of the palms of both hands, 500 cm 2This value is an estimate based on the TPSA (total palm surface area mean palm area with fingers), which is the arithmetic mean of the surface area of ​​one hand, as listed in Table 2 of Hyuk Choi et al., "Palm surface area database and estimation formula in Korean children using the alginate method" (Applied Ergonomics, Vol. 42 (2011), 873-882). More specifically, the total TPSA value for men (cm²) is as listed in Table 2. 2 ) and the total value of TPSA in women (cm 2 The arithmetic mean of ) was calculated, and twice this value was taken as the average area of ​​both palms.

[0074] (Preparation of bacterial suspension) For in vivo bactericidal activity evaluation, a bacterial suspension of Serratia bacteria prepared by the following method was used. The Serratia strain used was NBRC12648. This bacterium was cultured in LB liquid medium, the cells were collected by centrifugation, and then purified with distilled water (OD). 600 I adjusted it so that it equals 10.

[0075] (In vivo bactericidal properties: Table 1) The inner forearm of the subject was washed with Biore u Rg (manufactured by Kao Corporation). After waiting 5-10 minutes, the topical skin preparation composition was dispensed from a quantitative dispensing container in a single dispensing operation and applied to the skin surface of the inner forearm (1 cm). 2 The product was applied and spread over a (1cm x 1cm) area to an amount equivalent to that applied to the entire palms of both hands. The type of quantitative dispensing container and the amount of topical skin preparation composition dispensed in a single dispensing operation are shown in Table 1. After standing for 5 minutes to dry, a certain amount (1 μL / cm³) of the Serratia bacterium solution prepared by the above method is applied to the skin surface after the composition has been applied. 2 The solution was applied. After letting it stand for 3 minutes to dry, the applied bacterial solution was collected using two swabs. The collected bacteria were then cooled with ice to stop the reaction (the effect of the composition on the bacterial solution). Next, the number of viable bacteria was measured using the incubation reader "HiTS" (manufactured by Cynics Co., Ltd.) according to the following method, and the amount of decrease in bacterial count (number of viable bacteria / initial number of viable bacteria) was confirmed. Liquid cultures were performed at 37°C in the incubation leader "HiTS," and the absorbance (turbidity) at a wavelength of 600 nm was measured over time to create growth curves for the number of viable cells in the bacterial suspension. Simultaneously, bacterial suspensions with known viable cell counts were serially diluted, and culture and growth curves were created in the same manner to create calibration curves between the time to reach a certain turbidity and the number of viable cells. From the relationship between the time to reach a certain turbidity and the calibration curve, the number of viable cells in the bacterial suspension after the reaction was stopped was estimated, and the amount of decrease in the number of cells was confirmed. The degree of reduction in bacterial count (logarithmic reduction) is shown in Table 1, calculated by subtracting the logarithm value of the bacterial count reduction mentioned above. A larger value indicates higher in vivo bactericidal activity.

[0076] (In vivo bactericidal properties: Table 2) In the above, the same procedure as described above was followed, except that the skin topical formulations listed in Table 2 (Example 5, Comparative Example 1, and Comparative Example 8) were used, and the standing time after applying the composition to the skin surface was set to 1, 2, 3, 4, and 5 minutes, and data was obtained for each. The degree of reduction in bacterial count (logarithmic reduction value) was taken as the -log value of the bacterial count reduction and is shown in Table 2.

[0077] (Skin irritation) The inner forearm of each subject was washed with Biore u Rg (manufactured by Kao Corporation), and then rinsed with tap water and purified water. After waiting 5-10 minutes, the topical skin preparation composition was dispensed from a quantitative dispensing container in five steps and applied to a 9mm diameter filter paper (Patch Tester Torii, manufactured by Ribatape Pharmaceutical Co., Ltd.) in an amount equivalent to that applied to the entire palms of both hands, allowing it to soak in. This filter paper was placed on the skin surface of the inner forearm, sealed from above, and left to stand for 60 minutes. After 60 minutes, the seal was removed, and 30 minutes later, the skin surface was visually observed to see if redness was present. In Table 1, "-" indicates no redness, and "+" indicates redness. A "-" rating means no skin irritation.

[0078] [Table 1]

[0079] [Table 2]

[0080] <Ingredients in the composition> (A) Lactic acid: "Lactic acid (active: 90%)" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. (C1) Citric acid: Manufactured by Fujifilm Wako Pure Chemical Corporation (C2) Pyrrolidone carboxylic acid: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. pH adjuster: 1 mol / L hydrochloric acid aqueous solution and / or 1 mol / L sodium hydroxide aqueous solution • Hydrochloric acid solution: "Hydrochloric acid (1 mol / L)" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. • Sodium hydroxide aqueous solution: We used "NaOH (sodium hydroxide aqueous solution) 48%" manufactured by Kanto Chemical Co., Ltd., which was adjusted to a 1 mol / L sodium hydroxide aqueous solution. Benzalkonium chloride: "Benzalkonium chloride (50% aqueous solution)" manufactured by Tokyo Chemical Industry Co., Ltd.

[0081] Table 1 shows that the topical skin preparation of this embodiment provides high bactericidal activity on the skin surface while suppressing skin irritation. Furthermore, as shown in Table 2, the topical skin preparation composition used in this embodiment differs from the existing bactericide, benzalkonium chloride aqueous solution (Comparative Example 8), in that, after application to the skin, its bactericidal activity does not decrease over time, but rather tends to improve.

[0082] Examples 13-29 (Dispensing test of topical skin preparation composition) The amounts of each component shown in Table 3 were combined and mixed at room temperature. The pH was then adjusted to the pH shown in Table 3 using a 1 mol / L aqueous hydrochloric acid solution and / or a 1 mol / L aqueous sodium hydroxide solution as pH adjusters to prepare the topical skin preparation composition. The amounts listed in Table 3 represent the amount of active ingredient (mass%) of each component. This topical skin preparation composition was filled into quantitative dispensing containers (stroke-type spray container X or pump container Y) as described in Table 3 to obtain containerized topical skin preparations. The amount of topical skin preparation composition filled was 50 mL for spray container X and 120 mL for pump container Y. One dispensing operation was performed for each container, and the amount of composition dispensed in one dispensing operation was confirmed. One dispensing operation was performed by applying a load of 7 kg to the stroke of the quantitative dispensing container for 3 seconds.

[0083] (in vivo bactericidal) The in vivo bactericidal activity was evaluated using the same method as shown in Table 1.

[0084] (Feeling of use) 1.0 g of the topical skin preparation composition listed in Table 3 was dispensed and spread evenly over both hands until it was completely covered and allowed to dry. Then, the fingertips were wet with tap water at 20°C and a flow rate of 80 mL / s for 1 second, and the squeaking sensation when the fingertips were rubbed together was evaluated. The evaluation was conducted by five expert panelists according to the following criteria, and the average score was used as the evaluation value. <When using quantitative dispensing vessel X> 1: The squeaking sensation is stronger than in Example 13. 2: It feels slightly more squeaky than in Example 13. 3: Equivalent to Example 13 4: Slightly less squeaky than in Example 13. 5: Less squeaking than in Example 13. <When using quantitative dispensing vessel Y> 1: The squeaking sensation is stronger than in Example 16. 2: It feels slightly more squeaky than in Example 16. 3: Equivalent to Example 16 4: Slightly less squeaky than Example 16. 5: Less squeaking than in Example 16.

[0085] [Table 3]

[0086] <Types of quantitative dispensing vessels> X: Stroke-type spray container (Spray head: Takemoto Container Co., Ltd. "Z-155-C110"), 50mL capacity Y: Stroke-type pump container for "and and Custom Essence" manufactured by Kao Corporation, 120mL capacity.

[0087] <Ingredients in the composition> (A) Lactic acid: "Lactic acid (active: 90%)" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. (B1) Polyvinyl alcohol: "JC-40" manufactured by Nippon Bi-Poval Co., Ltd., degree of polymerization 4,000, saponification value 99.0-99.5 mol% (B2) Hydroxyethylcellulose 1: "Natrosol HEC 250HHX" manufactured by Ashland Co., Ltd. (B3) Hydroxyethylcellulose 2: "HEC Daicel 850SE" manufactured by Daicel Corporation pH adjuster: 1 mol / L hydrochloric acid aqueous solution and / or 1 mol / L sodium hydroxide aqueous solution • Hydrochloric acid solution: "Hydrochloric acid (1 mol / L)" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. • Sodium hydroxide aqueous solution: We used "NaOH (sodium hydroxide aqueous solution) 48%" manufactured by Kanto Chemical Co., Ltd., which was adjusted to a 1 mol / L sodium hydroxide aqueous solution. [Industrial applicability]

[0088] According to the present invention, it is possible to provide a topical skin preparation that exhibits excellent bactericidal or antiviral properties and has low skin irritation.

Claims

1. A topical skin preparation, wherein the topical skin preparation composition is contained in a metered-dose container, the composition contains one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid or salts thereof (A), when the acid present in the composition in acid form is designated as component (A1), the content of the component (A1) in the composition discharged from the metered-dose container by one discharge operation is 0.05 mg or more and 80 mg or less. A topical skin preparation.

2. The topical skin preparation according to claim 1, wherein the amount of the composition discharged from the metered-dose container by one discharge operation is 0.05 g or more and 3.0 g or less.

3. The topical skin preparation according to claim 1 or 2, wherein the viscosity of the composition at 25°C is 1.0 mPa·s or more and 10,000 mPa·s or less.

4. The topical skin preparation according to claim 1 or 2, wherein the pH of the composition at 25°C is 3.5 or more and 5.0 or less.

5. The topical skin preparation according to claim 1 or 2, wherein the content of the component (A) in the composition is 0.05% by mass or more and 10% by mass or less.

6. The topical skin preparation according to claim 1 or 2, wherein the content of the component (A1) in the composition is 0.02% by mass or more and 10% by mass or less.

7. The topical skin preparation according to claim 1 or 2, wherein the metal ion concentration in the composition is 0.002 mol / L or more and 0.50 mol / L or less.

8. The topical skin preparation according to claim 1 or 2, wherein the metered-dose container is a stroke-type pressing container, and the one discharge operation is an operation of pressing the container once at full stroke.

9. The component (A) is lactic acid or a salt thereof, the mass ratio [(C) / (A)] of the organic acid or its salt (C) other than the component (A) to the component (A) in the composition is less than 1, The topical skin preparation according to claim 1 or 2, wherein the pH of the composition at 25°C is 3.5 or more and 5.0 or less.

10. The composition further contains a nonionic thickener (B), The topical skin preparation according to claim 1 or 2, wherein the viscosity of the composition at 25°C is 100 mPa·s or more and 10,000 mPa·s or less.

11. A method for supplying one or more acids selected from the group consisting of lactic acid, pyruvic acid, and urocanic acid or salts thereof (A) to an application site on the skin surface, the method having the following steps (I) and (II) in sequence. Step (I): A step of cleaning the application site Step (II): A step of discharging the composition contained in the metering discharge container containing the component (A) by one discharge operation and supplying it to the application site, wherein when the acid present in the acid form among the acids present in the composition is designated as (A1), the content of the component (A1) in the composition discharged from the metering discharge container by one discharge operation is 0.05 mg or more and 80 mg or less.