WO2021246352A1

WO2021246352A1 - External dermatological composition for germicidal and virucidal use

Info

Publication number: WO2021246352A1
Application number: PCT/JP2021/020609
Authority: WO
Inventors: 安弘岡田; 利哉森川
Original assignee: 花王株式会社
Priority date: 2020-06-05
Filing date: 2021-05-31
Publication date: 2021-12-09
Also published as: TW202145995A; JP2021193078A

Abstract

An external dermatological composition for germicidal and virucidal use according to the present invention contains (A) one or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid, or a salt thereof, and (B) an acid other than component (A) that has a pKa of 3.0-5.0, or a salt thereof, wherein the content of component (A) is 0.1-10 mass% and the content of component (B) is 0.1-10 mass%, and the composition has a pH of 3.5-5.0.

Description

External skin composition for sterilization or virus killing

The present invention relates to an external skin preparation composition for sterilization or virus killing.

According to recent surveys, it is known that contact infection is the most common transmission route for bacteria or viruses in human daily life. Contact infections are mainly caused by the contact of fingers with contact objects such as bacteria or virus infected persons, doorknobs, handles, tableware, toys, other daily necessities, and interior goods.

There is a need for a method for preventing contact infection of bacteria or viruses due to such contact behavior in daily life.
As a method for preventing contact infection of bacteria or viruses via fingers, a method of sterilizing and disinfecting fingers by applying an alcohol-based disinfectant or the like is known. However, alcohol such as ethanol used as a sterilizing or disinfecting component is highly volatile, and the sustainability of the effect is not sufficient from the viewpoint of imparting a bactericidal and virus-killing effect to fingers. In addition, the alcohol component has limited application in terms of skin irritation to people with weak skin, people with low alcohol tolerance, and the like.

Therefore, a method of imparting a protective function against bacteria or viruses to the fingers is being studied in advance. According to this method, since the effect of preventing infection with bacteria or viruses can be continuously obtained, contact infection can be prevented even in an environment where there is no hand-washing place such as when going out. In particular, it is preferable in that infection can be prevented even when the contact object to which bacteria or viruses are attached is repeatedly contacted.

It is also known to use an organic acid or a salt thereof as a component for realizing sterilization or virus killing.
For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2008-523064), a compound or composition capable of reducing the skin pH to less than about 4 as a method for suppressing bacteria and viruses present on the skin surface of mammals. Disclosed are methods comprising contacting the skin with the skin for at least about 0.5 hours. Examples of the compound or composition capable of reducing the skin pH include those containing an organic acid such as a monocarboxylic acid or a polycarboxylic acid.
In Patent Document 2 (US Pat. No. 6,034,133), a virus-killing composition (hand lotion) containing citric acid, malic acid, and C1-6 alcohol is identified as having a rhinovirus cold. , Or a method of applying to the hands of a patient before exposure to rhinovirus to kill the rhinovirus and prevent the spread of the cold by the rhinovirus is disclosed.

The present invention provides the following [1] to [3].
[1] Other than (A) one or more acids selected from the group consisting of lactic acid, pyruvate and urocanic acid or salts thereof, and (B) component (A) having a pKa of 3.0 or more and 5.0 or less. The content of the component (A) is 0.1% by mass or more and 10% by mass or less, and the content of the component (B) is 0.1% by mass or more and 10% by mass or less. A composition for external use of skin for sterilization or virus killing, wherein the pH is 3.5 or more and 5.0 or less.
[2] A method for protecting the skin from bacteria or viruses, wherein one or more acids selected from the group consisting of (A) lactic acid, pyruvate and urocanic acid or salts thereof, and (B) pKa are 3. It contains an acid other than the component (A) which is 0 or more and 5.0 or less, or a salt thereof, and the content of the component (A) is 0.1% by mass or more and 10% by mass or less and the component (B). A method comprising the step of applying a composition having a content of 0.1% by mass or more and 10% by mass or less and a pH of 3.5 or more and 5.0 or less to the skin.
[3] Other than (A) one or more acids selected from the group consisting of lactic acid, pyruvate and urocanic acid or salts thereof, and (B) component (A) having a pKa of 3.0 or more and 5.0 or less. The content of the component (A) is 0.1% by mass or more and 10% by mass or less, and the content of the component (B) is 0.1% by mass or more and 10% by mass or less. A leave-on finger external preparation composition, wherein the pH is 3.5 or more and 5.0 or less, and the content of clay mineral is 3% by mass or less.

3 is a graph showing pH changes on fingers to which Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and a control external finger composition are applied.

[Composition of external skin preparation for sterilization or virus killing]
The composition for external use of skin for sterilization or virus killing of the present invention (hereinafter, also referred to as "composition of the present invention") is used.
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less, the content of the component (B) is 0.1% by mass or more and 10% by mass or less, and the pH is 3. 5 or more and 5.0 or less.
By having the above composition, the composition of the present invention is an external skin preparation composition which is excellent in bactericidal or virus-killing effect and its sustainability, has less skin irritation, and is highly safe for the human body.

Examples 2 of Patent Document 1 disclose compositions 2A to 2C containing citric acid and malic acid, of which the composition showing anti-rhinovirus activity has a composition pH of 2.3. Only thing 2A. Further, the pH of the anti-rhinovirus composition 2D containing citric acid and malic acid disclosed in Example 3 is 3.1. However, applying a low pH composition to the skin is not preferable from the viewpoint of skin irritation.
The hand lotion described in Patent Document 2 requires citric acid, malic acid, and C1-6 alcohol, and has not been shown to be virus-killing by hand lotions having other compositions.

An object of the present invention is to provide a composition for external skin for bactericidal or virus-killing, which has a good bactericidal or virus-killing effect and its sustainability, is less irritating to the skin, and is highly safe for the human body. ..

The present inventors have skin containing one or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and acids having a predetermined pKa or salts thereof, and having a predetermined pH range. It has been found that the external preparation composition can solve the above-mentioned problems.

According to the present invention, a composition for external use of a skin for sterilization or virus-killing, which has a good bactericidal or virus-killing effect and its sustainability, and has low skin irritation and high safety to the human body, and sterilization or killing. It is possible to provide a leave-on external preparation composition having a viral effect.

As used herein, the term "bactericidal or virus-killing effect" refers to (1) a bactericidal / virus-killing effect expressed against bacteria / viruses adhering to the skin surface after the composition of the present invention is applied to the skin surface. (2) Bactericidal / virus-killing effect developed by applying the composition of the present invention to bacteria / viruses adhering to the skin, (3) Effect of conditioning the skin to skin not mediated by bacteria / viruses, (4) ) The effect of protecting the skin from bacteria and viruses and keeping it hygienic, (5) the effect of preventing the transmission of bacteria and viruses through the skin and contact infection, and (6) the ability of the skin to protect against infection by bacteria and viruses. It includes concepts such as enhancing effect, and the composition of the present invention can be used in product forms such as hand disinfectants and hand cream cosmetics.

As used herein, the term "persistence of bactericidal or virus-killing effect" means the ability to exhibit a bactericidal or virus-killing effect even after a long period of time after applying the composition of the present invention to the skin. For example, it is preferable that the bactericidal or virus-killing effect can be exhibited even after preferably 30 minutes or more, more preferably 60 minutes or more, and further preferably 120 minutes or more after applying the composition of the present invention to the skin.
In the present invention, if the pH of the skin surface to which the composition is applied is maintained at a low pH, the bactericidal or virus-killing effect of the component (A) described later is enhanced, and more specifically, the composition is used. It is preferable that the ΔpH at 120 minutes after application is within 0.45.

Further, in the present specification, it is assumed that skin irritation can be suppressed if the pH of the composition at 25 ° C. is 3.5 or higher.

The fungus or virus to which the composition of the present invention exerts a bactericidal or virus-killing effect is not particularly limited as long as it is inactivated or killed by contact with an acid, and is, for example, an infection in a nursery school of the Ministry of Health, Labor and Welfare. It is considered that the microorganisms described in the disease control guidelines can be applied.
Specifically, the bacteria include anthrax, tuberculosis, hemolytic streptococcus, yellow staphylococcus, pneumoniae, etc., which are gram-positive bacteria, or Francisella tularensis, pest, brusella, and nasal bacillus, which are gram-negative bacteria. , Cholera, Salmonella, Shigella, Intestinal hemorrhagic Escherichia coli, Bordetella pertussis and the like. The viruses include arenavirus, ebola virus, porosity virus, Nyrovirus, Marburg virus, coronavirus, monkey pox virus, beta coronavirus, influenza virus, RS virus, herpesvirus, mumps virus, and varicella. -The herpes zoster virus, wind shin virus, hemp virus and the like, and non-enveloped viruses entererovirus, adenovirus, coxsackie virus, norovirus, rotavirus and the like can be mentioned.
In this example, Escherichia coli, enterococci, and Serratia marcescens are taken as examples to evaluate the bactericidal property, which is attached to microorganisms that can be ethically attached to the skin or to human skin. The evaluation method used is adopted from the viewpoint that it is a microorganism established in a public test method or an academic paper, and the fungus or virus targeted by the present invention is not limited thereto.

The reason why the composition of the present invention exerts the above effect is not clear, but it is considered as follows.
Lactic acid, pyruvic acid, and urocanic acid, which are components (A), originally exist on the surface of human skin by being supplied from sweat glands, and have a bactericidal and virus-killing function against bacteria, viruses, etc., especially on fingers. The present inventors have found that they are responsible. Therefore, it is considered that the composition for external use on the skin containing the component (A) can be a composition having a bactericidal or virus-killing effect, less skin irritation, and high human safety.
Regarding the above-mentioned bactericidal or virus-killing effect, it is known that even in the composition containing the component (A), the lower the pH, the higher the bactericidal or virus-killing effect. For example, lactic acid, which is the component (A), _{can take the form of an acid type (CH 3} CH (OH) COOH) and a dissociated type (CH ₃ CH (OH) COO ⁻ ) in an aqueous solution, but the acid type is more charged. It is considered that the acid type exhibits a higher bactericidal or virus-killing effect because it is easily taken up by bacteria or viruses. The acid type / dissociation type ratio of lactic acid depends on the pH, and when the pH exceeds 5, the acid type presence ratio decreases, and the ratio of lactic acid present in the acid type to the total amount of lactic acid blended is, for example, 5. It will be below the mol% level. The composition of the present invention exhibits a good bactericidal or virus-killing effect against bacteria or viruses when the pH is 5.0 or less.

On the other hand, even when the component (A) is used, there is a concern that the composition in the low pH range may cause skin irritation. Further, after the composition containing the component (A) is applied to the skin, there is also a problem that the pH of the skin surface rises with time and the bactericidal or virus-killing effect gradually decreases. This is because as the pH increases, the proportion of the acid-type component (A) on the skin surface also decreases.
Therefore, the present inventors have a pH in a relatively high range of 3.5 or more by using a predetermined amount of each of the component (A) and the component (B) which is an acid having a predetermined pKa or a salt thereof. It has been found that even a composition having less skin irritation can maintain a bactericidal or virus-killing effect for a long time after being applied to the skin. Since the component (B) is a weak acid or a salt thereof and has a buffering action, the composition used in combination with the component (A) suppresses the increase in pH over time even after the composition is applied to the skin. As a result, the ratio of the acid-type component (A), which is the main bactericidal or virus-killing component, is kept in a high range, so that the bactericidal or virus-killing effect is considered to be sustained for a long time.

The composition of the present invention is preferably a leave-on preparation. This is because the composition of the present invention can improve the bactericidal or virus-killing effect on bacteria or viruses and the sustainability thereof by leaving the component (A) which is a bactericidal or virus-killing component on the skin surface. Therefore, it is preferable that the composition of the present invention is applied to the skin and then left on the skin surface without being removed by washing with water or the like. Further, from the viewpoint of preventing contact infection by bacteria or viruses, it is more preferable to apply it to fingers even on the surface of the skin.

<Ingredient (A)>
The component (A) used in the composition of the present invention is one or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid, or salts thereof. Component (A) acts as a bactericidal or virus-killing component.
Examples of the salts of lactic acid, pyruvate and urocanic acid include alkali metal salts of lactic acid or pyruvate such as potassium salt and sodium salt; alkaline earth metal salts such as calcium salt and magnesium salt; amine salts; ammonium salts and the like. Be done. Among these, it is selected from the group consisting of alkali metal salts and alkaline earth metal salts of lactic acid, pyruvate and urocanic acid from the viewpoint of bactericidal or virus-killing effect and its sustainability improvement, and from the viewpoint of availability. More than one species is preferable, one or more selected from the group consisting of potassium salt, sodium salt, and calcium salt is more preferable, and one or more species selected from the group consisting of potassium lactate, sodium lactate, and calcium lactate is further preferable.
From the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability, lactic acid or a salt thereof is preferable as the component (A), and one or more selected from the group consisting of lactic acid, potassium lactate, sodium lactate, and calcium lactate is more preferable. , Lactic acid is more preferable.
Further, the content of lactic acid or a salt thereof in the total amount of the component (A) is preferably 80% by mass or more, more preferably 90% by mass or more, from the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability. Yes, most preferably 100% by mass.

The content of the component (A) in the composition of the present invention is 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.3% by mass or more, from the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability. Is 0.5% by mass or more, more preferably 0.8% by mass or more. Further, from the viewpoint of suppressing skin irritation, it is 10% by mass or less, preferably 8.0% by mass or less, more preferably 6.0% by mass or less, still more preferably 5.0% by mass or less, still more preferably. Is 3.0% by mass or less, more preferably 1.5% by mass or less. The content of the component (A) in the composition of the present invention is 0.1% by mass or more and 10% by mass or less, preferably 0.3% by mass or more and 8.0% by mass or less, and more preferably 0. .3% by mass or more and 6.0% by mass or less, more preferably 0.3% by mass or more and 5.0% by mass or less, still more preferably 0.3% by mass or more and 3.0% by mass or less, still more preferably 0. .3% by mass or more and 1.5% by mass or less, more preferably 0.5% by mass or more and 1.5% by mass or less.
In the present specification, when the component (A) contains a salt, the "content of the component (A)" means an amount converted into an acid.

The content of the component (A) present in the acid form in the composition of the present invention is preferably 0.01% by mass or more, more preferably 0. It is 1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.3% by mass or more. Further, from the viewpoint of suppressing skin irritation, it is preferably 7% by mass or less, more preferably 3.5% by mass or less, still more preferably 2.5% by mass or less, still more preferably 2% by mass or less, still more preferably. Is 1.5% by mass or less, more preferably 1% by mass or less. The content of the component (A) present in the acid form in the composition of the present invention is preferably 0.01% by mass or more and 7% by mass or less, more preferably 0.1% by mass or more and 3.5% by mass. % Or less, more preferably 0.1% by mass or more and 2.5% by mass or less, still more preferably 0.1% by mass or more and 2% by mass or less, still more preferably 0.1% by mass or more and 1.5% by mass or less. , More preferably 0.1% by mass or more and 1% by mass or less, still more preferably 0.2% by mass or more and 1% by mass or less, and even more preferably 0.3% by mass or more and 1% by mass or less.

The molar ratio of the component (A) present in the acid type to the total of the component (A) present in the acid type and the component (A) present in the dissociated type in the composition of the present invention [acid type / (acid type). + Dissociation type)] is preferably 0.068 or more, more preferably 0.12 or more, from the viewpoint of bactericidal or virus-killing effect and its sustainability improvement. Further, from the viewpoint of suppressing skin irritation, it is preferably 0.7 or less, more preferably 0.5 or less. The molar ratio [acid type / (acid type + dissociation type)] in the composition is preferably 0.068 or more and 0.7 or less, and more preferably 0.12 or more and 0.5 or less.
Specifically, the molar ratio can be calculated by the method described in Examples.

In addition, in this specification, "the component (A) which exists in an acid form in a composition" means the component (A) which exists as lactic acid, pyruvic acid and urocanic acid in a composition. , "Dissociated component (A) in the composition" means a component of the component (A) that is present as lactic acid ion, pyruvate ion and urocanate ion in the composition.

<Ingredient (B)>
The component (B) used in the composition of the present invention is an acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof. The composition of the present invention exerts a buffering action by containing the component (A) and the component (B), and even after applying the composition having a pH in a relatively high range of 3.5 or more to the skin, the skin It is considered that the increase in pH of the surface over time can be suppressed. As a result, it is considered that the decrease in the ratio of the acid type component (A) on the skin surface is suppressed, and the bactericidal or virus-killing effect can be sustained for a long time.
As used herein, pKa means the acid dissociation constant in an aqueous solution at 25 ° C. For acids having a plurality of pKa such as the first acid dissociation constant (PKa ₁ ) and the second acid dissociation constant (PKa ₂ ), any acid having a pKa of 3.0 or more and 5.0 or less is required. For example, it shall be included in the acid specified in the component (B).

The acid in the component (B) has a pKa of 3 as the acid in the component (B) from the viewpoint of improving the bactericidal or virus-killing effect of the skin surface to which the composition is applied and its persistence, and suppressing the skin irritation. It is 9.0 or more, preferably 3.2 or more, more preferably 3.5 or more, still more preferably 3.7 or more, still more preferably 4.0 or more. Further, from the viewpoint of exerting a buffering action when used in combination with the component (A), the pKa is 5.0 or less, preferably 4.7 or less, and more preferably 4.5 or less. The pKa of the acid in the component (B) is 3.0 or more and 5.0 or less, preferably 3.2 or more and 4.7 or less, more preferably 3.5 or more and 4.5 or less, and further preferably 3. It is 7.7 or more and 4.5 or less, more preferably 4.0 or more and 4.5 or less. In the case of the component (B) having a plurality of pKa in the range of pKa of 3.0 or more and 5.0 or less, the pKa having a larger value keeps the pH of the composition at 5.0 or less. , It is considered that it contributes to the bactericidal or virus-killing effect of the skin surface to which the composition is applied and the effect of improving its sustainability.

The acid in the component (B) may be either an organic acid or an inorganic acid as long as it has the above pKa, but an organic acid is preferable from the viewpoint of suppressing skin irritation.
The organic acid may be a monovalent acid or a polyvalent acid, but is preferably a polyvalent acid from the viewpoint of improving the sustainability of the bactericidal or virus-killing effect on the skin surface to which the composition is applied.
As the organic acid, ascorbic acid and a carboxylic acid compound are preferable. These may be either low molecular weight compounds or high molecular weight compounds, but from the viewpoint of water solubility, they are preferably low molecular weight compounds having 8 or less carbon atoms, and more preferably 6 or less carbon atoms.

Specific examples of the acid in the component (B) include ascorbic acid (primary acid dissociation constant pKa ₁ : 4.17, secondary acid dissociation constant pKa ₂ : 11.6, molecular weight 176.1 g / mol); gluconic acid ( Acid dissociation constant pKa: 3.86, molecular weight 196 g / mol), citric acid (primary acid dissociation constant pKa ₁ : 3.09, secondary acid dissociation constant pKa ₂ : 4.8, tertiary acid dissociation constant pKa ₃ : 6.41, molecular weight 192.1 g / mol (anhydrous)), malic acid (primary acid dissociation constant pKa ₁ : 3.4, secondary acid dissociation constant pKa ₂ : 5.1, molecular weight 134.1 g / mol) , Tartrate (first acid dissociation constant pKa ₁ : 2.82, second acid dissociation constant pKa ₂ : 3.96, molecular weight 150.1 g / mol) and other hydroxycarboxylic acids; fumaric acid (first acid dissociation constant pKa _1). : 3.02, secondary acid dissociation constant pKa ₂ : 4.38, molecular weight 116.1 g / mol), succinic acid (first dissociation constant pKa ₁ : 4.2, second dissociation constant pKa ₂ : 5.6, Molecular weight 118.1 g / mol), adipic acid (first dissociation constant pKa ₁ : 4.42, second dissociation constant pKa ₂ : 5.42, molecular weight 146.1 g / mol), etc. Valuable carboxylic acids; acidic polymers having a pKa in the above range, such as polyacrylic acid; and the like; these can be used alone or in combination of two or more.
Among the above, the molecular weight of the acid in the component (B) is preferably 50 g / mol or more, more preferably 80 g / mol or more, from the viewpoint of improving the sustainability of the bactericidal or virus-killing effect. Further, from the viewpoint of improving the bactericidal or virus-killing effect, it is preferably 300 g / mol or less, and more preferably 150 g / mol or less. The molecular weight of the acid in the component (B) is preferably 50 g / mol or more and 300 g / mol or less, and more preferably 80 g / mol or more and 150 g / mol or less.

Examples of the acid salt in the component (B) include alkali metal salts such as potassium salt and sodium salt of the acid; alkaline earth metal salts such as calcium salt and magnesium salt; amine salt; ammonium salt and the like. Among these, from the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability, one or more selected from the group consisting of the alkali metal salt of the acid and the alkaline earth metal salt is preferable, and potassium salt, sodium salt, and calcium are preferable. More preferably, one or more selected from the group consisting of salts.

From the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability, the component (B) is one selected from the group consisting of ascorbic acid, hydroxycarboxylic acid, polyvalent carboxylic acid having no hydroxy group, and salts thereof. The above is preferable, a polyvalent carboxylic acid having no hydroxy group or a salt thereof is more preferable, a polyvalent carboxylic acid having no hydroxy group is more preferable, and one or more selected from the group consisting of succinic acid and adipic acid is preferable. Even more preferred, succinic acid is even more preferred.

The content of the component (B) in the composition of the present invention is 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.3% by mass or more, from the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability. Is 0.5% by mass or more, more preferably 0.7% by mass or more. Further, from the viewpoint of suppressing skin irritation, it is 10% by mass or less, preferably 7% by mass or less, further preferably 5% by mass or less, still more preferably 3% by mass or less. The content of the component (B) in the composition of the present invention is 0.1% by mass or more and 10% by mass or less, preferably 0.3% by mass or more and 7% by mass or less, more preferably 0.5. It is by mass% or more and 5% by mass or less, more preferably 0.7% by mass or more and 5% by mass or less, and even more preferably 0.7% by mass or more and 3% by mass or less.
In the present specification, when the component (B) contains a salt, the "content of the component (B)" means an amount converted into an acid.

The total content of the component (A) and the component (B) in the composition of the present invention is preferably 0.2% by mass or more, more preferably 0. 3% by mass or more, still more preferably 0.5% by mass or more, still more preferably 0.8% by mass or more, still more preferably 1% by mass or more, still more preferably 1.2% by mass or more, still more preferably. It is 1.5% by mass or more, more preferably 1.7% by mass or more. Further, from the viewpoint of suppressing skin irritation, it is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 8% by mass or less, still more preferably 6% by mass or less, still more preferably 5% by mass. % Or less, more preferably 3% by mass or less. The specific range of the total content of the component (A) and the component (B) in the composition of the present invention is preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.3% by mass or more. 10% by mass or less, more preferably 0.5% by mass or more and 8% by mass or less, still more preferably 0.8% by mass or more and 6% by mass or less, still more preferably 1% by mass or more and 6% by mass or less, still more preferable. Is 1.2% by mass or more and 6% by mass or less, more preferably 1.5% by mass or more and 5% by mass or less, still more preferably 1.7% by mass or more and 5% by mass or less, still more preferably 1.7% by mass. % Or more and 3% by mass or less.

Further, the mass ratio (B / A) of the component (B) to the component (A) in the composition of the present invention is preferably 0.1 or more, more preferably 0.1 or more, from the viewpoint of improving the sustainability of the bactericidal or virus-killing effect. Is 0.2 or more, more preferably 0.5 or more. Further, from the viewpoint of improving the bactericidal or virus-killing effect, it is preferably 20 or less, more preferably 10 or less, still more preferably 8 or less, still more preferably 7 or less, still more preferably 6 or less, still more preferably 5 or less. be. The mass ratio (B / A) in the composition of the present invention is preferably 0.1 or more and 20 or less, more preferably 0.2 or more and 10 or less, still more preferably 0.2 or more and 8 or less, and further. It is preferably 0.2 or more and 7 or less, more preferably 0.2 or more and 6 or less, still more preferably 0.2 or more and 5 or less, and even more preferably 0.5 or more and 5 or less.

The composition of the present invention preferably further contains water from the viewpoint of dissolving the component (A) and the component (B) and facilitating application to the skin surface. The content of water in the composition of the present invention is preferably 10% by mass or more, more preferably 30% by mass or more, still more preferably 50% by mass or more, still more preferably 70% by mass or more, and more preferably. Is 99.8% by mass or less, more preferably 99% by mass or less. The content of water in the composition of the present invention is preferably 10% by mass or more and 99.8% by mass or less, more preferably 30% by mass or more and 99.8% by mass or less, and further preferably 50% by mass or more and 99. It is 8.8% by mass or less, more preferably 70% by mass or more and 99% by mass or less.

From the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability, the composition of the present invention preferably limits the content of clay minerals used for adsorbing and removing oil components and proteins. Examples of the clay minerals include silt; marine silt; tanakura clay; bentnite, montmorillonite, herculite, byderite, nontonite, saponite, hectrite, lucentite, soconite and stibunchite smectite clay minerals; kaolin, nacrite, deckite, halloysite. And kaolin-based clay minerals such as chrysotile; antigolite-based clay minerals such as antigolite, amesite and cronsteadite; pyrophyllite-based clay minerals such as pyrophyllite and talc (talc); , Celadonite, sericite, mica (mica), white mica, chrome white mica, black mica and other mica clay minerals; vermiculite clay minerals such as vermiculite; and green mudstone (chlorite) and other green mudstone clay minerals. Can be mentioned.

Here, limiting the content of clay mineral means that the content of clay mineral in the composition of the present invention is preferably 3% by mass or less, more preferably 1% by mass or less, and further preferably substantially contained. Means not.

The total content of the component (A), the component (B) and water in the composition of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably, from the viewpoint of obtaining the effect of the present invention. Is 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 100% by mass or less.

In addition to the above, the composition of the present invention may contain other components, for example, acids other than the components (A) and (B) or salts thereof, surfactants, thickeners, pH adjusters, as necessary. It can also contain an ultraviolet absorber, an antioxidant, an antiseptic, an antiperspirant, a fragrance, a moisturizer and the like.
Among the above, the viewpoint of improving the stability of the composition and the viewpoint of improving the shape-retaining property of the composition and allowing it to stay on the skin surface at the time of application, further improving the bactericidal or virus-killing effect and its sustainability. Therefore, it is preferable to include a surfactant in the composition of the present invention.
Surfactants include nonionic surfactants, anionic surfactants, cationic surfactants (excluding quaternary ammonium salts), amphoteric surfactants (excluding alkyldiaminoethylglycine hydrochloride and alkylpolyaminoethylglycine). ) Etc. can be mentioned. Among these, one or more selected from the group consisting of nonionic surfactants and anionic surfactants is preferable from the viewpoint of further improving the bactericidal or virus-killing effect and its sustainability.

Examples of the nonionic surfactant include alkyl glucoside, sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, and polyethylene glycol fatty acid ester from the viewpoint of improving the bactericidal or virus-killing effect. And one or more selected from the group consisting of polyoxyethylene alkyl ethers are preferred. Further, the average number of moles of ethyleneoxy groups added in polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, polyethylene glycol fatty acid ester, and polyoxyethylene alkyl ether (hereinafter referred to as "EO average number of added moles"". ) Is more preferably 3 or more and 20 or less, further preferably 3 or more and 15 or less, further preferably 5 or more and 9 or less, and further preferably 5 or more and 8 or less. The EO average number of moles added is a number average value.
Among the above, polyoxyethylene alkyl ether is more preferable as the nonionic surfactant. From the viewpoint of improving the bactericidal or virus-killing effect, a polyoxyethylene alkyl ether having 8 or more and 20 or less alkyl groups constituting the polyoxyethylene alkyl ether is preferable, and the EO average number of moles of the polyoxyethylene alkyl ether is 3. It is more preferably 20 or less, further preferably 3 or more and 15 or less, further preferably 5 or more and 9 or less, and even more preferably 5 or more and 8 or less.

Further, as the nonionic surfactant, the HLB value is preferably 8 or more and 16 or less, more preferably 10 or more and 14 or less, and further preferably 10 or more and 13 or less, from the viewpoint of improving the bactericidal or virus-killing effect.
HLB (Hydrophilic-Lipophilic Balance) indicates the molecular weight of the hydrophilic group portion of the total molecular weight of the surfactant, and for nonionic surfactants, Griffin's It is calculated by the formula.
The HLB of a mixed surfactant composed of two or more types of nonionic surfactants is a phase-added average of the HLB values of each nonionic surfactant based on the blending ratio, and is as follows. Desired.
Mixed HLB = Σ (HLBx × Wx) / ΣWx
HLBx indicates the HLB value of the nonionic surfactant X.
Wx indicates the mass (g) of the nonionic surfactant X having a value of HLBx.

The anionic surfactant comprises an alkyl sulfate ester salt, an alkyl phosphate ester salt, a polyoxyethylene alkyl ether sulfate ester salt, and a polyoxyethylene alkyl ether phosphate salt from the viewpoint of improving the bactericidal or virus-killing effect. One or more selected from the group is preferable.

When a surfactant is used, the content of the surfactant in the composition of the present invention is preferably 0.01% by mass or more, more preferably 0. It is 05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more, and preferably 10% by mass or less, more preferably 5 from the viewpoint of suppressing skin irritation. It is mass% or less, more preferably 3% by mass or less, still more preferably 2% by mass or less.
The specific range of the content of the surfactant in the composition of the present invention is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 5% by mass or less, and further preferably 0. .1% by mass or more and 3% by mass or less, more preferably 0.3% by mass or more and 2% by mass or less.

The composition of the present invention can be used as a sterilizing or virus-killing composition even if the ethanol content is low, from the viewpoint that the composition uses the component (A) as a sterilizing or virus-killing component. From this viewpoint and from the viewpoint of suppressing skin irritation, the content of ethanol in the composition is preferably 70% by mass or less, more preferably 50% by mass or less, still more preferably 30% by mass or less, still more preferably. Is 10% by mass or less, and more preferably 0% by mass.

The composition of the present invention is a quaternary ammonium salt such as benzalkonium chloride and benzethonium chloride from the viewpoint of using the component (A) as a bactericidal or virus-killing component; alkyldiaminoethylglycine hydrochloride, alkylpolyamino. Amphoteric surfactant-based disinfectants such as ethylglycine; biguanides such as chlorhexidine and chlorhexidine gluconate; sodium hypochlorite; lower alcohols other than ethanol such as isopropanol; aldehydes such as glutaral, phthalal and formarin; iodotinki; It can be used as a bactericidal or virus-killing composition without or in a small amount of a general-purpose disinfectant such as phenol; chlorhexidine solution; peracetic acid; oxidol; When a general-purpose bactericidal agent is blended in the composition, benzalkonium chloride is used from the viewpoint of maintaining the skin pH in a low range by the component (A) and the component (B), thereby enhancing the bactericidal sustaining effect of the general-purpose bactericidal agent. It is preferable to use a quaternary ammonium salt such as nium or benzethonium chloride.
When a general-purpose fungicide is blended, the blending amount is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, still more preferably, from the viewpoint of sterilizing or virus-killing effect and improving its sustainability. Is 0.05% by mass or more. On the other hand, from the viewpoint of suppressing skin irritation, it is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 3% by mass or less, still more preferably 1% by mass. It is more preferably 0.07% by mass or less, further preferably 0.03% by mass or less, and most preferably 0% by mass in substance.
In the present invention, the above-mentioned general-purpose fungicide and also acting as a surfactant is defined as a general-purpose fungicide.

The composition of the present invention preferably has a low content of polyol from the viewpoint of improving usability. The polyol referred to here refers to a compound other than the component (A) and the component (B) having two or more hydroxy groups in the molecule. The content of the polyol in the composition is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 3% by mass or less, from the viewpoint of improving the usability. , More preferably, it is substantially 0% by mass.

Further, the ratio of the total content of ethanol, isopropanol, and polyol to the content of water in the composition of the present invention is a mass ratio [(ethanol +) from the viewpoint of suppressing skin irritation and improving usability. Isopropanol + polyol) / water] is preferably 2 or less, more preferably 1 or less, still more preferably 0.5 or less, still more preferably 0.1 or less.

<pH>
The composition of the present invention has a pH of 3.5 or higher, preferably 3.7 or higher, from the viewpoint of suppressing skin irritation. Further, from the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability, it is 5.0 or less, preferably 4.5 or less. The specific pH range of the composition of the present invention is 3.5 or more and 5.0 or less, preferably 3.7 or more and 4.5 or less.
The pH is a value at 25 ° C., and can be specifically measured by the method described in Examples.

The form of the composition of the present invention is not particularly limited, and may be, for example, solid, liquid, gel, or cream. From the viewpoint of ease of application to the skin, it is preferably in the form of a gel or cream. The composition may be in the form of an emulsified composition, and the emulsified composition may be either an oil-in-water emulsified composition or a water-in-oil emulsified composition.

As described above, the composition of the present invention is preferably used as a leave-on preparation, but the dosage form of the preparation is not particularly limited. For example, a stick preparation provided with a solid composition; a roll-on preparation filled with a liquid composition. Alternatively, a spray formulation; a formulation in which a liquid, gel-like or cream-like composition is filled in a bottle, tube, dispenser-type container or the like, a sheet product impregnated with the composition, or the like can be mentioned.

Examples of the product form of the composition of the present invention include lotions, gels, sprays, creams, etc. for fingers or bodies.

[Defense method]
The present invention is also a method of protecting the skin from bacteria or viruses.
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less, the content of the component (B) is 0.1% by mass or more and 10% by mass or less, and the pH is 3. Provided is a method having a step of applying a composition of 5 or more and 5.0 or less to the skin (hereinafter, also simply referred to as “the method of the present invention”).
According to the method of the present invention, the skin is protected from bacteria or viruses by the bactericidal or virus-killing effect and its persistence, and the skin irritation is low, so that the safety to the human body is high.

The composition of the present invention described above is preferable as the composition used in the method of the present invention, and the details and suitable range thereof are the same as those of the composition. The fungus or virus to be protected by the method of the present invention is the same as described above.

The method for applying the composition to the skin can be appropriately selected depending on the dosage form, application site, etc. of the composition, and for example, the composition can be applied to the skin by application, spraying, or the like.
The body part to which the composition is applied is not particularly limited, and can be applied to any body part such as fingers, upper arms, lower limbs, neck, and torso. From the viewpoint of cutting off the route of infection and transmission of bacteria and viruses by contact between humans and objects, it is preferable to apply it to public objects and fingers that often touch the nose and mouth of oneself in daily life.

In the process, the amount of component (A) present in the acid form in the skin surface to which the said composition, from the viewpoint of sterilization or virucidal effect and its durability improves skin 1 cm ² per preferably 0. It is 2 μg or more, more preferably 1.5 μg or more, still more preferably 1.7 μg or more, still more preferably 1.8 μg or more, still more preferably 2 μg or more. Further, from the viewpoint of suppressing skin irritation, it is preferably 200 μg or less, more preferably 100 μg or less, and further preferably 50 μg or less. The amount of component (A) in the skin surface to which the said composition, present in acid form, preferably per skin 1 cm ² is 0.2μg least 200μg or less, more preferably 1.5μg least 200μg or less, more preferably Is 1.7 μg or more and 100 μg or less, more preferably 1.8 μg or more and 50 μg or less, and even more preferably 2 μg or more and 50 μg or less.
The "amount of the acid-type component (A) present on the skin surface to which the composition is applied" is the acid-type component derived from the composition on the skin surface at the time of applying the composition (the composition). It is the total amount of A) and the acid-type component (A) naturally present on the skin surface, and can be specifically obtained by the method described in Examples.

The molar ratio of the component (A) present in the acid type to the total of the component (A) present in the acid type and the component (A) present in the dissociated type on the skin surface to which the composition is applied [acid type / ( Acid type + dissociation type)] is preferably 0.15 or more, more preferably 0.17 or more, still more preferably 0.18 or more, from the viewpoint of bactericidal or virus-killing effect and its sustainability improvement. Further, from the viewpoint of suppressing skin irritation, it is preferably 0.70 or less, more preferably 0.50 or less, still more preferably 0.30 or less. The molar ratio [acid type / (acid type + dissociation type)] on the skin surface to which the composition is applied is preferably 0.15 or more and 0.70 or less, more preferably 0.17 or more and 0.50 or less. , More preferably 0.18 or more and 0.30 or less.
In the above molar ratio [acid type / (acid type + dissociation type)], the component (A) derived from the composition on the skin surface at the time of applying the composition and the component naturally present on the skin surface ( Both A) are considered. The molar ratio can be specifically determined by the method described in Examples.

The pH of the skin surface after applying the composition is preferably 3.50 or higher, more preferably 3.70 or higher, still more preferably 3.90 or higher, from the viewpoint of suppressing skin irritation. Further, from the viewpoint of bactericidal or virus-killing effect and improvement of its sustainability, the pH of the skin surface after applying the composition is preferably 4.60 or less, more preferably 4.55 or less, still more preferably 4.50. It is as follows. The pH of the skin surface after applying the composition is preferably 3.50 or more and 4.60 or less, more preferably 3.70 or more and 4.55 or less, and further preferably 3.90 or more and 4.50 or less. Is.
From the viewpoint of improving the sustainability of the bactericidal or virus-killing effect, the pH of the skin surface is preferably in the above range even after 30 minutes or more, more preferably 60 minutes or more after applying the composition.
The pH of the skin surface is a measured value at an environmental temperature to which the method of the present invention is applied, and can be specifically measured by the method described in Examples.

In the method of the present invention, it is preferable that the composition is not removed by washing with water or the like after being applied to the skin, but remains on the skin surface. This is because the composition can be used as a leave-on preparation to leave the component (A), which is a bactericidal or virus-killing component, on the skin surface, thereby imparting a bactericidal or virus-killing effect and its persistence.
The composition may be applied to the skin after washing the skin with water, soap, body soap, hand soap or the like in advance, or may be applied to the unwashed skin. The washed skin is in a state in which components such as lactic acid that are naturally present are washed away and the bactericidal or virus-killing property against bacteria and viruses existing in the outside world is reduced. It is more preferable to apply a substance to carry out the method of the present invention.

[Leave-on finger external preparation composition]
The present invention is also a leave-on finger external preparation composition.
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less, the content of the component (B) is 0.1% by mass or more and 10% by mass or less, and the pH is 3. 5 or more and 5.0 or less,
Provided is a leave-on finger external preparation composition having a clay mineral content of 3% by mass or less.
The leave-on finger external preparation composition of the present invention has a high bactericidal or virus-killing effect and its durability, and has low skin irritation, so that it is highly safe for the human body.
The components (A) and (B) used in the leave-on finger external preparation composition, the clay minerals specified in the leave-on finger external preparation composition, and the details and suitable ranges thereof are the same as those of the composition of the present invention.

The composition of the present invention is described below from the viewpoint of providing a bactericidal or virus-killing external preparation composition for bactericidal or virus-killing, which has a high bactericidal or virus-killing effect and its durability, is less irritating to the skin, and is highly safe for the human body. It contains the component (A) and the component (B), the content of the component (A) is 0.1% by mass or more and 1.5% by mass or less, and the content of the component (B) is 0.3% by mass or more. It is preferably a composition for external use of fingers for sterilization or virus killing, which is 10% by mass or less and has a pH of 3.5 or more and 5.0 or less.
(A) Lactic acid or a salt thereof (B) An acid other than the component (A) having a pKa of 3.5 or more and 4.5 or less, or a salt thereof.

The composition of the present invention has the following components (A) and the following components (A) from the viewpoint of providing a leave-on hand-finger external preparation composition having a bactericidal or virus-killing effect, high durability thereof, low skin irritation, and high safety to the human body. When the content of the component (B) is contained, the content of the component (A) is 0.1% by mass or more and 1.5% by mass or less, and the content of the component (B) is 0.3% by mass or more and 10% by mass or less. It is preferable that the composition is a leave-on external preparation for fingers having a pH of 3.5 or more and 5.0 or less.
(A) Lactic acid or a salt thereof (B) An acid other than the component (A) having a pKa of 3.5 or more and 4.5 or less, or a salt thereof.

With respect to the above embodiments, the present invention further discloses the following embodiments.
<1>
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
An external skin composition for sterilization or virus killing, wherein the pH at 25 ° C. is 3.5 or more and 5.0 or less.
<2>
The content of the component (A) in the external preparation composition for skin is preferably 0.3% by mass or more and 8.0% by mass or less, more preferably 0.3% by mass or more and 6.0% by mass or less, still more preferably. Is 0.3% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 3.0% by mass or less, still more preferably 0.3% by mass or more and 1.5% by mass or less, still more. The composition for external skin preparation for sterilization or virus killing of <1>, preferably 0.5% by mass or more and 1.5% by mass or less.
<3>
The content of the component (A) present in the acid form in the external preparation composition for skin is preferably 0.01% by mass or more and 7% by mass or less, more preferably 0.1% by mass or more and 3.5% by mass. Hereinafter, more preferably 0.1% by mass or more and 2.5% by mass or less, still more preferably 0.1% by mass or more and 2% by mass or less, still more preferably 0.1% by mass or more and 1.5% by mass or less, More preferably 0.1% by mass or more and 1% by mass or less, further preferably 0.2% by mass or more and 1% by mass or less, still more preferably 0.3% by mass or more and 1% by mass or less, <1>. Or, an external skin preparation composition for sterilizing or killing virus according to <2>.
<4>
The pKa of the acid in the component (B) is preferably 3.2 or more and 4.7 or less, more preferably 3.5 or more and 4.5 or less, still more preferably 3.7 or more and 4.5 or less, still more preferably 4. .0 or more and 4.5 or less, the composition for external skin preparation for sterilization or virus killing of any one of <1> to <3>.
<5>
The acid in the component (B) is at least one selected from the group consisting of ascorbic acid, gluconic acid, citric acid, malic acid, tartaric acid, fumaric acid, succinic acid, adipic acid, and polyacrylic acid, <1>. ~ <4> The composition for external skin preparation for sterilizing or killing a virus according to any one of <4>.
<6>
Sterilization of any one of <1> to <5>, wherein the molecular weight of the acid in the component (B) is preferably 50 g / mol or more and 300 g / mol or less, and more preferably 80 g / mol or more and 150 g / mol or less. Or a composition for external use of skin for virus killing.
<7>
The content of the component (B) in the external preparation composition for skin is preferably 0.3% by mass or more and 7% by mass or less, more preferably 0.5% by mass or more and 5% by mass or less, still more preferably 0.7. The composition for external skin preparation for sterilization or virus killing according to any one of <1> to <6>, which is 5% by mass or more, more preferably 0.7% by mass or more and 3% by mass or less.
<8>
The mass ratio (B / A) of the component (B) to the component (A) in the external preparation composition for skin is preferably 0.1 or more and 20 or less, more preferably 0.2 or more and 10 or less, and further preferably 0. .2 or more and 8 or less, more preferably 0.2 or more and 7 or less, still more preferably 0.2 or more and 6 or less, still more preferably 0.2 or more and 5 or less, still more preferably 0.5 or more and 5 or less. An external skin preparation composition for sterilizing or killing a virus according to any one of <1> to <7>.
<9>
The external preparation composition for skin further contains water, and the content of water in the composition is preferably 10% by mass or more and 99.8% by mass or less, more preferably 30% by mass or more and 99.8% by mass or less. , More preferably 50% by mass or more and 99.8% by mass or less, still more preferably 70% by mass or more and 99% by mass or less, for external use on the skin for sterilization or virus killing of any one of <1> to <8>. Agent composition.
<10>
The content of the clay mineral in the external skin preparation composition is preferably 3% by mass or less, more preferably 1% by mass or less, and further preferably substantially not contained, any of <1> to <9>. A composition for external use of skin for sterilization or virus killing.
<11>
The content of the general-purpose bactericidal agent in the external preparation composition for skin is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 3% by mass or less, still more. Of <1> to <10>, preferably 1% by mass or less, still more preferably 0.07% by mass or less, still more preferably 0.03% by mass or less, and substantially 0% by mass. The external skin preparation composition for sterilizing or killing any one of the viruses.

<12>
The skin external preparation composition for sterilization or virus killing according to any one of <1> to <11>, wherein the pH of the external skin preparation composition at 25 ° C. is preferably 3.7 or more and 4.5 or less.
<13>
Any of <1> to <12>, wherein the content of lactic acid or a salt thereof in the total amount of the component (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass. 1. A composition for external use of skin for sterilization or virus killing.
<14>
In addition, surfactants, preferably nonionic surfactants, anionic surfactants, cationic surfactants (excluding quaternary ammonium salts), and amphoteric surfactants (alkyldiaminoethylglycine hydrochloride and alkylpolyaminoethyl). A surfactant composition for sterilizing or virus-killing any one of <1> to <13>, which contains at least one selected from the group consisting of (excluding glycine).
<15>
The surfactants include nonionic surfactants, anionic surfactants, cationic surfactants (excluding quaternary ammonium salts), and amphoteric surfactants (alkyldiaminoethylglycine hydrochloride and alkylpolyaminoethylglycine). One or more selected from the group consisting of (excluding), preferably one or more selected from the group consisting of nonionic surfactants and anionic surfactants, more preferably nonionic surfactants <14>. Surfactant composition for sterilizing or killing viruses.
<16>
The nonionic surfactant consists of a group consisting of alkyl glucoside, sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, polyethylene glycol fatty acid ester, and polyoxyethylene alkyl ether. For sterilization or virus killing of <15>, which is one or more selected polyoxyethylene alkyl ethers, preferably polyoxyethylene lauryl ethers, more preferably polyoxyethylene alkyl ethers having 8 or more and 20 or less alkyl groups constituting the polyoxyethylene alkyl ethers. Skin external preparation composition.
<17>
The average number of moles of ethyleneoxy groups added to the polyoxyethylene sorbitan fatty acid ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, polyethylene glycol fatty acid ester, and polyoxyethylene alkyl ether is 3 or more and 20 or less, preferably 3 or more and 15 or less. , More preferably 5 or more and 9 or less, still more preferably 5 or more and 8 or less, the composition for external skin preparation for sterilization or virus killing of <16>.
<18>
The bactericidal or virus-killing virus of any one of <15> to <17>, wherein the HLB value of the nonionic surfactant is 8 or more and 16 or less, preferably 10 or more and 14 or less, and more preferably 10 or more and 13 or less. Skin external preparation composition for.
<19>
The anionic surfactant is at least one selected from the group consisting of an alkyl sulfate ester salt, an alkyl phosphate ester salt, a polyoxyethylene alkyl ether sulfate ester salt, and a polyoxyethylene alkyl ether phosphate. A composition for external use on the skin for sterilizing or killing a virus according to any one of 15> to <18>.
<20>
The content of the surfactant in the external preparation composition for skin is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 5% by mass or less, still more preferably 0.1% by mass. % Or more and 3% by mass or less, more preferably 0.3% by mass or more and 2% by mass or less, the composition for external skin preparation for sterilization or virus killing according to any one of <14> to <19>.
<21>
The content of ethanol in the external preparation composition for skin is preferably 70% by mass or less, more preferably 50% by mass or less, still more preferably 30% by mass or less, still more preferably 10% by mass or less, and further. The composition for external skin preparation for sterilization or virus killing according to any one of <1> to <20>, preferably substantially 0% by mass.
<22>
The content of the polyol in the external preparation composition for skin is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, still more preferably 3% by mass or less, and further. The composition for external skin preparation for sterilization or virus killing according to any one of <1> to <21>, preferably substantially 0% by mass.
<23>
The ratio of the total content of ethanol, isopropanol, and polyol to the content of water in the skin external preparation composition is preferably 2 or less as the mass ratio [(ethanol + isopropanol + polyol) / water], more preferably. Is 1 or less, more preferably 0.5 or less, still more preferably 0.1 or less, and the composition for external skin preparation for sterilization or virus killing according to any one of <1> to <22>.
<24>
An external skin composition for sterilizing or virus-killing any one of <1> to <23>, which is a leave-on preparation.
<25>
A way to protect the skin from bacteria or viruses,
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
A method comprising the step of applying a composition having a pH of 3.5 or more and 5.0 or less at 25 ° C. to the skin, preferably fingers.
<26>
The content of the component (A) in the composition is preferably 0.3% by mass or more and 8.0% by mass or less, more preferably 0.3% by mass or more and 6.0% by mass or less, and further preferably 0. 3% by mass or more and 5.0% by mass or less, more preferably 0.3% by mass or more and 3.0% by mass or less, still more preferably 0.3% by mass or more and 1.5% by mass or less, still more preferably 0. The method of <25>, which is 0.5% by mass or more and 1.5% by mass or less.
<27>
The method of <25> or <26>, wherein the content of lactic acid or a salt thereof in the total amount of the component (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass. ..
<28>
The method according to any one of <25> to <27>, wherein the molecular weight of the acid in the component (B) is preferably 50 g / mol or more and 300 g / mol or less, and more preferably 80 g / mol or more and 150 g / mol or less. ..
<29>
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
A leave-on finger external preparation composition having a pH of 3.5 or more and 5.0 or less at 25 ° C.
<30>
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
A composition for external use of a skin for suppressing bacterial or virus transmission, which has a pH of 3.5 or more and 5.0 or less at 25 ° C.
<31>
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
An external skin preparation composition for protecting against bacteria or viruses, which has a pH of 3.5 or more and 5.0 or less at 25 ° C.
<32>
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
A composition for external use on the skin for preventing transmission of bacteria or viruses and prevention of contact infection, which has a pH of 3.5 or more and 5.0 or less at 25 ° C.
<33>
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
Contains,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less.
The content of the component (B) is 0.1% by mass or more and 10% by mass or less.
An external skin composition for protecting fingers, having a pH of 3.5 or more and 5.0 or less at 25 ° C.
<34>
The composition for external use on the skin according to <33>, which is used to protect fingers from bacteria or viruses.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the scope of the examples. In this example, various measurements and evaluations were performed by the following methods.

(PH)
The pH of the composition was measured at 25 ° C. with an electrode 6637-10D (manufactured by HORIBA, Ltd.). The pH of the skin surface (palm) was measured with an electrode Skin-pH-Meter PH905 (Courage + Khazaka).

(Mole ratio of component (A) [acid type / (acid type + dissociation type)])
The molar ratio of the component (A) in the composition and on the skin surface after the composition was applied was determined by the following formula. Incidentally, the acid form "HA", the dissociative ^- denoted as "A".
^{pH = pKa + log (A -} / HA)
^{log (A - / HA) =} pH-pKa
^{A - / HA = 10 ^ (} pH-pKa)
^{A - = 10 ^ (pH-} pKa) × HA
From the above, the acid form mole ratio of [the acid form / (acid type + dissociation type)] is ^{HA / (HA + A -)} = HA / (^ HA + 10 (pH-pKa) × HA)
= 1 / (1 + 10 ^ (pH-pKa))
Here, when lactic acid is used as the component (A) (pKa = 3.86),
Mole ratio [lactic acid / (lactic acid + lactic acid ion)] = 1 / (1 + 10 ^ (x-3.86))
(X indicates the pH of the composition or the pH of the skin surface.)
When the component (A) is composed of a plurality of components, the following calculation method is defined in the present invention. By measuring the pH of the composition by the method described above and substituting the pKa of each of the plurality of components into the above formula, the molar ratio [acid type / (acid type + dissociation type)] of each component is obtained. Next, by adding the molar ratios [acid type / (acid type + dissociation type)] of each component, the molar ratio [acid type] of the component (A) when a plurality of types of components (A) are used. / (Acid type + dissociation type)] can be obtained.

(Preparation of bacterial solution)
For the bactericidal evaluation, a bacterial solution of Escherichia coli, Enterococcus, or Serratia prepared by the following method was used.
NBRC3301 strain was used as Escherichia coli, NBRC3181 strain was used as enterococcus, and NBRC12648 strain was used as Serratia bacterium. Each of these bacteria was cultured in an LB liquid medium, and the cells were collected by centrifugation and then adjusted to _{OD 600 = 10 using pure water.}

(Bactericidal evaluation 1: Escherichia coli and enterococci bactericidal)
The subject's hands were washed with "Biore u Rg" (manufactured by Kao Corporation) and rinsed with tap water for 30 seconds and pure water for 10 seconds in order. After waiting for 1 to 5 minutes, the prepared compositions of Examples 1 to 11 and Comparative Examples 1 to 4 were ^{uniformly applied to the palm in a fixed amount (3 μL / 3 cm 2} ), and then allowed to stand for 3 minutes to dry. .. At this time, the pH of the skin surface at the site where the composition was applied was measured by the above method, and from this pH value, lactic acid with respect to the total amount of lactic acid and lactic acid ions on the skin surface after the composition was applied by the above formula. [Lactic acid / (lactic acid + lactic acid ion)] was determined.
Then, the bacterial solution of Escherichia coli or enterococcus prepared by the above method was uniformly applied to the site where the composition was applied on the palm in a fixed amount (3 μL / 3 cm ² ). After allowing to stand for 3 minutes, the bacterial solution applied using two swabs is collected, and the viable bacterial count is measured by the following method using an incubation leader "HiTS" (manufactured by Sinix Co., Ltd.) to determine the bacterial count. The amount of decrease (number of surviving bacteria / initial number of viable bacteria) was confirmed.
[Measurement of decrease in bacterial count]
The collected bacterial solution was liquid-cultured at 37 ° C. in an incubation leader "HiTS", and the absorbance (turbidity) at a wavelength of 600 nm was measured over time to create a growth curve of the viable cell count in the bacterial solution. At the same time, the bacterial solution having a known viable cell count was serially diluted, and the culture and growth curve were similarly prepared to prepare a calibration curve between the time to reach a certain turbidity and the viable cell count. From this calibration curve, the number of surviving bacteria in the collected bacterial solution was estimated, and the decrease in the number of bacteria was confirmed.
The degree of decrease in the number of bacteria is shown in Table 1 by taking the -log value of the amount of decrease in the number of bacteria. The higher the value of "-log" for Escherichia coli or enterococci, the higher the bactericidal activity.

(Bactericidal evaluation 2: Serratia bactericidal property)
[Bactericidal property (logarithmic decrease value) 5 minutes and 30 minutes after application of the composition]
The inner part of the forearm of the subject was washed with "Biore u Rg" (manufactured by Kao Corporation), and rinsed with tap water for 30 seconds and with pure water for 10 seconds in order. After waiting for 1 to 5 minutes, the compositions of Examples 2 and 12 and Comparative Examples 1 and 5 are ^{uniformly applied to the skin surface of the inner part of the forearm in a fixed amount (2 μL / cm 2} ), and then allowed to stand for 5 minutes or 30 minutes. Placed and dried. At this time, the pH of the skin surface at the site where the composition was applied was measured by the above method, and from this pH value, lactic acid with respect to the total amount of lactic acid and lactic acid ions on the skin surface after the composition was applied by the above formula. [Lactic acid / (lactic acid + lactic acid ion)] was determined.
Then, the bacterial solution of Serratia marcescens prepared by the above method was uniformly applied to the site where the composition was applied on the palm in a fixed amount (1 μL / cm ² ). After allowing to stand for 3 minutes, the applied bacterial solution was collected using two swabs, and the number of surviving bacteria was measured by the same method as described above using an incubation leader "HiTS" (manufactured by Sinix Co., Ltd.). The amount of decrease in the number of bacteria (surviving number / initial viable number) was confirmed.
The degree of decrease in the number of bacteria (logarithmic decrease value) is shown in Table 1 by taking the -log value of the amount of decrease in the number of bacteria. The larger this value is, the higher the bactericidal property is.

Examples 1 to 12 and Comparative Examples 1 to 5 (preparation and evaluation of a composition for external use of fingers)
After blending each component in the amounts shown in Table 1 and mixing at room temperature, a hydrochloric acid aqueous solution having a concentration of 1 mol / L and / or an aqueous sodium hydroxide solution having a concentration of 1 mol / L was used as a pH adjuster except for Comparative Example 1. The pH was adjusted to 4.0 to prepare a finger external preparation composition. The blending amount shown in the table is the amount of the active ingredient (% by mass) of each component except for sodium dihydrogen phosphate. For sodium dihydrogen phosphate, the compounding amount in terms of phosphoric acid is shown in Table 1. Further, the pKa described in the table is the pKa of the acid in the component (B).
Various evaluations were carried out by the above method using the obtained composition. The results are shown in Table 1.

The components listed in Table 1 are as follows.
Lactic acid: Lactate (active: 90%) Made by Fujifilm Wako Junyaku Co., Ltd. Succinic acid: Succinic acid Made by Fujifilm Wako Junyaku Co., Ltd. Ascorbic acid: Ascorbic acid Made by Fujifilm Wako Junyaku Co., Ltd. Apple acid: Apple Acid Fujifilm Wako Junyaku Co., Ltd. Citric acid: Citric acid Fujifilm Wako Junyaku Co., Ltd. Adipic acid: Adipic acid Fujifilm Wako Junyaku Co., Ltd. Sodium dihydrogen phosphate: Anhydrous sodium dihydrogen phosphate FUJIFILM Wako Junyaku Co., Ltd. Polyoxyethylene (EO average number of added moles 6) Lauryl ether: Emargen 108 Kao Co., Ltd., HLB 12.1
Polyoxyethylene (Average number of moles added by EO: 9) Lauryl ether: Emargen 109P, manufactured by Kao Corporation, HLB13.6
Aqueous solution of hydrochloric acid: Hydrochloride (1 mol / L) Wako Pure Chemical Industries, Ltd. Sodium hydroxide aqueous solution: NaOH (sodium hydroxide aqueous solution) 48% Kanto Kagaku Co., Ltd. made 1 mol / L aqueous solution of sodium hydroxide Adjusted and used.
Benzalkonium chloride: Benzalkonium chloride aqueous solution manufactured by Tokyo Chemical Industry Co., Ltd.

From Table 1, it can be seen that the composition of this example has a higher skin bactericidal effect than the composition of the comparative example. It is considered that this is because the pH of the skin surface is kept in the range of about 4.6 or less, and the ratio of the acid type component (A), which is the main bactericidal component, present on the skin surface is high.
Further, in the comparison between Comparative Example 1 and Comparative Example 5, the bactericidal effect was hardly enhanced even if benzalkonium chloride was contained, whereas in the comparison between Example 2 and Example 12, the composition of the present invention was used. It can be seen that the bactericidal effect is significantly enhanced by containing benzalkonium chloride. This is considered to be based on the following reasons.
-The composition containing benzalkonium chloride and adjusted to pH 4.0 with hydrochloric acid (Comparative Example 5) has a bactericidal effect equivalent to that of pure water. This is because the composition of Comparative Example 5 does not have the ability to buffer the skin pH, the skin pH rises after application, and the surface charge of the skin tilts negatively, so that cationic benzalkonium chloride is applied to the skin. This is because the bactericidal effect of benzalkonium chloride is suppressed by facilitating adsorption.
-In the composition (Example 12) in which benzalkonium chloride is contained in the composition of the present invention, the skin pH is maintained at around pH 4 by the buffering capacity of the components (A) and (B), so that the skin can be treated. It is possible to suppress the negative inclination of the surface charge, and as a result, suppress the adsorption of benzalkonium chloride on the skin, and exert the bactericidal effect of benzalkonium chloride. As a result, the bactericidal effect of the composition of the present invention can be enhanced by containing benzalkonium chloride in combination with the bactericidal effect of the components (A) and (B).

(Low pH sustaining effect)
The subject's hands were washed with "Biore u Rg" (manufactured by Kao Corporation) and rinsed with tap water for 30 seconds and pure water for 10 seconds in order. After waiting for 3 minutes, a fixed amount (3 μL / 3 cm ² ) of the composition for evaluation was uniformly applied to the palm. After a lapse of a certain period of time, the pH of the skin surface at the site where the composition was applied was measured by the above method.
The compositions of Example 1, Comparative Example 2, and Comparative Example 3 were used for the evaluation, and an aqueous hydrochloric acid solution (pH 1.5) was used as a control composition for external fingers. The pH change on the fingers after application of the composition is shown in the graph of FIG.

From FIG. 1, the following can be seen.
The compositions of Example 1, Comparative Example 2 and Comparative Example 3 all have a pH of 4.0, but the pH behavior on the fingers to which the composition is applied is different.
It can be seen that the initial pH of the fingers to which the composition of Example 1 is applied is also low, and the pH is maintained in a relatively low range even after a long period of time.
On the other hand, when the composition of Comparative Example 3 having the same content of the component (A) as that of Example 1 and not containing the component (B) was used, Comparative Example 1 (deionized water) was used. The initial pH is lower than that of the case and the case of using Comparative Example 2 (deionized water adjusted to pH 4.0), but the pH is increased with the passage of time.
Even when an aqueous hydrochloric acid solution having a pH of 1.5 is used, the initial pH decreases to the same level as that of the composition of Example 1, but the pH increases significantly with the passage of time.

As the composition of the present invention, the formulations shown in Table 2 can be prepared by conventional methods.

The components listed in Table 2 are as follows.
Lactic acid: Lactic acid (active: 90%) Made by Fujifilm Wako Pure Chemical Industries, Ltd. Succinic acid: Succinic acid Made by Fujifilm Wako Pure Chemical Industries, Ltd. Polyoxyethylene (EO average number of moles added 6) Lauryl ether: Emargen 108 Kao ( Made by HLB 12.1
Polyoxyethylene (Average number of moles added by EO: 9) Lauryl ether: Emargen 109P, manufactured by Kao Corporation, HLB13.6
Sodium hydroxide: NaOH (sodium hydroxide aqueous solution) 48% Kanto Chemical Co., Ltd. was used after adjusting to a 1 mol / L aqueous solution of sodium hydroxide.

According to the present invention, it is possible to provide an external skin preparation composition for bactericidal or virus-killing, which has a good bactericidal or virus-killing effect and its sustainability, is less irritating to the skin, and is highly safe for the human body. ..

Claims

(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less, the content of the component (B) is 0.1% by mass or more and 10% by mass or less, and the pH is 3. An external skin preparation composition for bactericidal or virus-killing, which is 5 or more and 5.0 or less.
The skin external preparation composition according to claim 1, wherein the pKa of the acid in the component (B) is 3.5 or more and 4.5 or less.
The skin external preparation composition according to claim 1 or 2, which is a leave-on preparation.
A way to protect the skin from bacteria or viruses,
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less, the content of the component (B) is 0.1% by mass or more and 10% by mass or less, and the pH is 3. A method comprising the step of applying a composition of 5 or more and 5.0 or less to the skin.
(A) One or more acids selected from the group consisting of lactic acid, pyruvic acid and urocanic acid or salts thereof, and
(B) An acid other than the component (A) having a pKa of 3.0 or more and 5.0 or less, or a salt thereof,
The content of the component (A) is 0.1% by mass or more and 10% by mass or less, the content of the component (B) is 0.1% by mass or more and 10% by mass or less, and the pH is 3. 5 or more and 5.0 or less,
A leave-on finger external preparation composition having a clay mineral content of 3% by mass or less.