JP7335642B2 - lice repellent - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pediculicide containing menthol or the like as an active ingredient effective in exterminating lice.

BACKGROUND ART Conventionally, sanitary pest control agents that are applied to humans and animals for use in order to prevent damage from lice and prevent the spread of damage are known. In general, lice often infest nursery school children, kindergarten children, and children in the lower grades of elementary school. Preparations containing DEET, ie N,N-diethyl-m-toluamide, are known.

For example, Patent Document 1 discloses a repellent against sanitary insect pests such as lice, which can be used for the human body and the like, contains essential oils such as DEET and menthol, and water.

In addition, Patent Document 2 discloses a spray composition comprising a solvent such as peppermint oil, menthol, and ethanol for exterminating sanitary pests such as mites.

JP 2014-201581 A

Japanese Patent Application Laid-Open No. 2004-10578

However, regarding the sanitary pest control agent for lice and the like described in Patent Document 1, it has been reported that excessive and repeated use of DEET over a long period of time causes symptoms of convulsions and coma in children. While it has become difficult to use DEET as an active ingredient, there has been a problem that essential oils such as menthol alone cannot kill lice.

In addition, Patent Document 2 discloses that a spray composition containing peppermint oil, menthol, etc. can kill mites, but it is not shown whether it has the same effect on lice. In addition, since the spray composition contains excessive menthol, side effects such as excessive redness and heat may occur when used by methods such as direct application or spraying on the outer skin of the human body. Concerned.

Therefore, it is an object of the present invention to provide a pediculicide that can exterminate lice with less irritation and less side effects even when used directly on human skin for external use.

[1] That is, the pediculicide according to the present invention contains menthol, an acid and a surfactant as active ingredients, and the acid is phosphoric acid, acetic acid, citric acid, or hydrochloric acid. It is a pediculicide.

[2] The pediculicide according to [1] , wherein the menthol and the acid are mixed in a ratio of menthol/acid=100/1 to 1/500.

INDUSTRIAL APPLICABILITY According to the pediculicide of the present invention, lice can be exterminated with less irritation and less side effects when applied directly to human skin.

Hereinafter, embodiments of the pediculicide of the present invention will be described in detail. In addition, when there is a notation indicating a range in the explanation, it includes the upper limit and the lower limit.

The menthol of the present invention is a cyclic monoterpene, a type of alcohol, and a volatile organic compound. Menthol is an active ingredient that exhibits synergistic effects of exterminating lice by coexisting with acid. Since menthol has diastereomers and enantiomers, 1-menthol is preferable because it has a great extermination effect on lice.

As for menthol, commercially available chemically synthesized products can be used, but since mint and mint contain a large amount of menthol, mint and mint extracts can be used.

The amount of menthol is preferably 0.1 to 20% by weight, more preferably 0.3 to 15% by weight, more preferably 0.5% by weight, in the pediculicide composition of the present invention. ~10% by weight is most preferred. When the amount of menthol blended is within this range, lice can be exterminated by a synergistic effect with the acid, and side effects can be caused even if the menthol is directly in contact with the outer skin of the human body by a method such as coating or spraying for use on the human body. does not cause irritation. Moreover, when using a mint or mint extract, it is preferable to adjust the menthol contained within the above range.

Acids of the present invention are inorganic acids and organic acids that exhibit acidity when dissolved in a water-soluble solvent such as water or ethanol. Acid is an active ingredient that exhibits synergistic action and effect of exterminating lice by coexisting with menthol.

Specific examples of acids include hydrogen halides such as phosphoric acid and hydrochloric acid, inorganic acids such as sulfuric acid, nitric acid, and boric acid, acids having a sulfo group, acids having a carboxyl group, acids having a phosphate ester bond, and the like. is preferred. As the organic acid having a sulfo group, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid and the like are preferable. Organic acids having a carboxy group include formic acid, acetic acid, propionic acid, glycolic acid, lactic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, gluconic acid, tartaric acid, malic acid, aspartic acid, maleic acid, fumaric acid, Citric acid, benzoic acid, salicylic acid, anisic acid, ascorbic acid, glucuronic acid, benzilic acid and the like are preferred. Preferred acids having a phosphate ester bond include oleyl phosphate and dioleyl phosphate. These compounds can be used singly or in combination of two or more.

The amount of the acid to be added is preferably 0.01 to 20% by weight, more preferably 0.03 to 15% by weight, and more preferably 0.05% by weight in the pediculicide composition of the present invention. ~10% by weight is most preferred. When the amount of the acid is within this range, lice can be exterminated by a synergistic effect with menthol.

The mixing ratio of menthol and acid is preferably menthol/acid = 100/1 to 1/500, more preferably 50/1 to 1/300, and 20/1 to 1/200. is most preferred. When the blending ratio of menthol and acid is within the above range, the menthol and acid synergistically act to exterminate lice even when the blending ratio of menthol and acid is minimal.

In the present invention, alcohols having 2 to 6 carbon atoms and water can be used as solvents.

The alcohol having 2 to 6 carbon atoms is an alcohol having 2 to 6 total carbon atoms that is liquid under the conditions of 1 atmospheric pressure and 25°C. Preferred examples of alcohols having 2 to 6 carbon atoms include ethanol, 1-propanol, isopropanol, 1-butanol, ethylene glycol, propylene glycol, diethylene glycol and glycerin. The blending ratio of the alcohol having 2 to 6 carbon atoms is preferably 5 to 60% by weight, more preferably 10 to 50% by weight and volume. When the alcohol having 2 to 6 carbon atoms is blended in this range, it is possible to impart water solubility to the pediculicide of the present invention and to uniformly dissolve and disperse menthol and acid.

The water is preferably water that conforms to Japanese Pharmacopoeia standards, for example, ordinary water such as tap water or well water, and either distillation, ion exchange treatment with an ion exchange membrane, ultrafiltration treatment with an ultrafiltration membrane, or Purified water obtained by treating ordinary water with a combination thereof, and sterilized purified water obtained by sterilizing purified water by heating or the like can be mentioned. The amount of water to be blended is preferably the remainder excluding menthol and acid.

In order to use the pediculicide of the present invention as a cleansing agent for hair, a surfactant may be added to remove oily components adhering to the hair and scalp. As surfactants, it is preferable to use nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like. By incorporating surfactants, menthol and acid, which are active ingredients in the formulation, are uniformly dispersed, and the long-term uniformity of the formulation can be maintained. By spreading uniformly, the effect of exterminating lice can be fully expressed.

As the nonionic surfactant, specifically, a nonionic surfactant having an HLB of 10 to 17 is preferable, and furthermore, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl Ethers, polyoxyethylene alkyl ethers such as polyoxyethylene myristyl ether, polyoxyethylene octyldodecyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan Polyoxyethylene sorbitan fatty acid esters such as monooleate, polyoxyethylene fatty acid esters such as polyethylene glycol monolaurate and polyethylene glycol monostearate, polyoxyethylene alkylamines, polyoxyethylene glycerin monolaurate, polyoxyethylene glycerin monolaurate Palmitate, polyoxyethylene glycerin fatty acid esters such as polyoxyethylene glycerin monooleate, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, glycerin monolaurate, glycerin Preferred are glycerin fatty acid esters such as monopalmitate, glycerin monostearate and glycerin distearate, alkylamine oxides such as coconut alkylamine oxide having an alkyl group having 12 to 14 carbon atoms, and alkylalkanolamides.

The anionic surfactant is preferably at least one selected from carboxylic acid type, sulfonic acid type, sulfate ester type, and phosphate ester type, and not only liquid or solid 100% pure compounds, but also It may be an aqueous solution diluted with a certain amount of water. Carboxylic acid-type anionic surfactants include sodium laurate, sodium stearate, sodium laureth-6 carboxylate (sodium polyoxyethylene (4.5) lauryl ether acetate), sodium lauroyl sarcosinate, sodium octanoate, and decanoic acid. Sodium, sodium myristate, sodium palmitate, coconut oil fatty acid (C8-18) sodium sarconsin and the like are preferred. Sulfonic acid-type anionic surfactants include sodium laurylsulfoacetate, sodium 1-hexanesulfonate, sodium 1-octanesulfonate, sodium 1-decanesulfonate, sodium 1-dodecanesulfonate, sodium toluenesulfonate, and cumene. Sodium sulfonate, sodium naphthalene sulfonate, disodium naphthalene disulfonate, trisodium naphthalene trisulfonate, sodium alpha olefin sulfonate, and the like are preferred. Sulfate ester type anionic surfactants include sodium lauryl sulfate, sodium myristyl sulfate, sodium laureth sulfate (polyoxyethylene (3) sodium lauryl ether sulfate), sodium cetyl sulfate, sodium cocoglyceryl sulfate (hardened coconut oil fatty acid glyceryl sulfate sodium), triethanolamine lauryl sulfate, ammonium lauryl sulfate, triethanolamine laureth sulfate, and the like. As the phosphate ester type anionic surfactant, sodium lauryl phosphate, sodium polyoxyethylene cetyl ether phosphate (polyoxyethylene (5) cetyl ether sodium phosphate), lauryl phosphoric acid, potassium lauryl phosphate, etc. are preferable. .

To the pediculicide of the present invention, a feel agent such as polyether silicone can be added in order to improve the feeling of use, such as imparting a dry feeling when it adheres to the skin of the human body, and an antioxidant. Vitamin C (ascorbic acid), vitamin E (tocopherol), BHT (dibutylhydroxytoluene), BHA (butylhydroxyanisole), and the like can be added as additives.

Furthermore, various fragrances can be added in order to impart fragrance to the pediculicide of the present invention as long as the pediculicidal effect is not reduced.

Examples of the present invention will be specifically described below. In addition, the present invention is not limited to the following examples.

<Example 1>
10% by weight of phosphoric acid, 0.5% by weight of l-menthol, 10% by weight of ethanol, and 79.5% by weight of purified water as the remainder were added and stirred until uniform to obtain a pediculicide.

<Examples 2 to 13>
A pediculicide was obtained in the same manner as in Example 1 according to the mixing ratio of the acid and l-menthol shown in Table 1. In Examples 10 and 12, mint oil containing 30% by weight of l-menthol was used instead of l-menthol.

<Comparative Examples 1 to 4>
A pediculicide was obtained in the same manner as in Example 1 according to the blending ratio of l-menthol shown in Table 2.

<Evaluation: Extermination rate of lice>
The extermination rate of the obtained pediculicide was confirmed by the following test method using lice as sanitary pests. That is, 20 body lice were placed in a petri dish, and the lice were immersed in the pediculicide obtained in each example and each comparative example for 5 minutes, then pulled out, washed with water for 1 minute, and then washed for 24 hours. Observed the state after the passage. Observed after 24 hours, counted the number of living insects (number of survivors) and the number of dead insects (dead insects) that were stationary and dead or in a state similar to that (dead insects), eradication rate (%) = {dead insects /(surviving number + dead insect number)} x 100, the efficacy was calculated as a percentage to calculate the extermination rate. If the extermination rate was less than 50%, it was judged that there was no extermination effect, if it was 50% or more and less than 70%, it was judged that there was an extermination effect, and if it was 70% or more, it was judged that there was a sufficient extermination effect. Table 1 shows the extermination effect of each example and each comparative example.

From this Table 1, in Comparative Examples 1 to 4, even if phosphoric acid, citric acid, acetic acid, and l-menthol are used alone as active ingredients, the lice extermination rate is as low as 0 to 10%, but the implementation In Examples 1 to 13, by using l-menthol and one acid selected from among phosphoric acid, citric acid, acetic acid and hydrochloric acid in a predetermined compounding ratio, the lice extermination rate is as good as 70% or more. It was found to show good results. From this, it was found that the combined use of menthol and acid as active ingredients produces an effect of acting synergistically to exterminate lice.

Claims (2)

A pediculicide comprising menthol, an acid and a surfactant as active ingredients, wherein the acid comprises any one of phosphoric acid, acetic acid, citric acid and hydrochloric acid . 2. The pediculicide according to claim 1 , wherein the blending ratio of said menthol and said acid is said menthol/ said acid=100/1 to 1/500.