JP2020109126A - Louse repelling method - Google Patents

Abstract

To provide a louse repelling method which can repel a louse in a sustained manner.SOLUTION: The present invention provides a louse repelling method where, menthyl ester, represented by formula (I), is applied to a place at which a louse is to be repelled, so that the amount of applied menthyl ester is at least 3 mg/cm2. (In formula (I), R is H or a C1-4 alkyl group).SELECTED DRAWING: None

Description

The present invention relates to a lice repellent method capable of continuously repelling lice.

Human lice include human lice (for example, head lice, white lice, etc.) and lice. Among these lice, the head lice infestation rate has been increasing in recent years, and particularly, the damage to children and children who live in groups is remarkable. In addition, infections of children and families have been reported.

Head lice are parasitic on human hair and live by sucking blood from the scalp. Therefore, when it is parasitized by head lice, the scalp is accompanied by strong itching due to blood feeding. In addition, bacteria or viruses may be infected from the blood-sucking part or scratches caused by strong itching, which may cause infection, swelling of lymph nodes, or fever.

Conventionally, in order to prevent such damages of lice, a method of using shampoo containing a pyrethroid compound on hair infested with lice is generally used (Patent Document 1). However, extermination using shampoo is a method of exterminating lice that have already parasitized, and some time is required until extermination. Therefore, until the lice are exterminated, the above-mentioned damage such as itching cannot be avoided.

Therefore, it is preferable to prevent the lice from parasitizing itself, rather than eliminating the parasitic lice. However, lice are difficult-to-control pests, and lice repellents are rarely studied. Under such circumstances, Patent Document 2 describes that N,N-diethyl-m-toluamide (DEET) is effective as a lice repellent component. However, since DEET has a unique odor, the odor becomes a problem during use. Therefore, in order to use DEET, it is necessary to improve the discomfort during use by using it together with a masking agent and the repellent effect is not sufficient.

JP 2009-7291 A JP, 2014-201581, A

An object of the present invention is to provide a lice repellent method capable of continuously repelling lice.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and completed the present invention.
(1) A method for repelling lice, which comprises treating the menthyl ester represented by the following formula (I) at a location where repelling lice is desired so that the treatment amount is at least 3 mg/cm ² .
In formula (I), R represents H or an alkyl group having 1 to 4 carbon atoms.

According to the lice repellent method of the present invention, lice can be repelled continuously.

It is explanatory drawing for demonstrating the method of the contact repellent test performed in the Example.

The lice repellent of the present invention contains menthyl ester as an active ingredient. Menthyl ester is a kind of terpene and is a compound having a structure in which menthol and an organic acid are esterified. The menthyl ester contained in the lice repellent of the present invention is not particularly limited and has, for example, a structure represented by the following formula (I).

R in the formula (I) represents H or an alkyl group having 1 to 4 carbon atoms. Among these, R is preferably H, a methyl group or an ethyl group. When R is a methyl group, the menthyl ester is menthyl acetate represented by the following formula (II), when R is H, menthyl formate, and when R is an ethyl group, menthyl propanoate. Menthyl ester is easily metabolized and decomposed when it comes into contact with the human body or is inhaled, and it is highly safe. In addition, there is also a feature that a refreshing feeling can be obtained when processed by the human body.

Further, in consideration of usability, an excipient may be used within a range that does not impair the effects of the present invention. Excipients are appropriately selected depending on the desired dosage form. For example, when preparing a liquid lice repellent, as the excipient, water, alcohols (eg, ethanol, glycerin, etc.), polyols such as polyalkylene glycols and their ethers, solvents such as glycol ethers are used. used. The liquid preparation may be prepared by dissolving or suspending menthyl ester in these solvents. On the other hand, when preparing a solid louse repellent, polyols such as polyalkylene glycol and ethers thereof, starch, dextrin, lactose, resin, inorganic powder, pulp and the like are used as excipients.

The amount of the excipient used is not particularly limited, but if it is diluted too much, a large amount of the lice repellent must be treated to treat an effective amount of, for example, menthyl ester. Therefore, the amount of the excipient used is usually 20 parts by mass or less, and preferably about 2 to 10 parts by mass with respect to 1 part by mass of the menthyl ester.

Furthermore, the lice repellent of the present invention may include a fragrance, an antioxidant, a deodorant, a dye, a chelating agent, a surfactant, a retention agent, a pH adjuster, a bactericide, a fungicide, etc., if necessary. Additives may be included.

The dosage form of the lice repellent of the present invention is not particularly limited. The lice repellent of the present invention may be a liquid preparation or a solid preparation such as powder, granules and tablets. In order to repel lice using the lice repellent of the present invention, the repellent of the present invention may be treated at the place where the lice is desired to be repelled. The treatment amount is not particularly limited, and in order to repel lice efficiently, the treatment amount of menthyl ester may be at least 3 mg/cm ² , more preferably at least 5 mg/cm ² . The type of lice repelled by the lice repellent of the present invention is not particularly limited, and examples thereof include head lice, lice, and lice.

The place where lice are desired to be repelled, that is, the subject to be treated with the repellent of the present invention includes, for example, those considered to be the lice infection route. Specific examples of the object to be treated include clothing, bedding (pillows, duvets, etc.), towels, bath towels, undressing baskets, hair brushes, etc., and are appropriately selected depending on the type of lice to be repelled. Alternatively, the human body such as hair may be included in the object to be treated and directly applied to the human body.

When the lice repellent of the present invention is used as a liquid agent, it may be used as it is, for example, it may be used in a spray form or an aerosol form. Examples of the propellant used in the aerosol form include liquefied petroleum gas, dimethyl ether, 1,3,3,3-tetrafluoropropene, nitrogen gas, carbon dioxide gas and the like.

Specific examples of the method of treating the liquid agent include a method of spraying the object to be treated with the liquid agent, a method of immersing the object to be treated in the liquid agent, and a method of applying the liquid agent to the object to be treated with a brush or the like. When used for hair, it may be used in the form of a hair styling agent or a treatment.

On the other hand, when the lice repellent of the present invention is used as a solid agent, for example, the solid agent may be put in a bag of a desired size and put in a closet or a closet together with clothes, towels, bath towels and the like. Well, you can put it in a pillow or a futon. Alternatively, the bag body containing the repellent may be sewn on the lining of clothing or the like. Further, in the case of powder, it may be directly sprayed on the object to be treated.

For example, in the case of head lice, lice attaches to towels, bath towels, hairbrushes, pillows, etc. used by the infected person, and infection occurs when another person uses these towels and the like with the lice attached. Therefore, by treating these towels and the like with the lice repellent of the present invention, even if the lice adheres, the lice are repelled, so that the lice do not exist from these towels and the like.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Example 1)
Menthyl acetate and acetone were mixed to prepare an acetone solution of menthyl acetate having an appropriate concentration. Next, filter paper (manufactured by Advantech Toyo Co., Ltd., product number: 00021150) is cut into a circle having a diameter of 9 cm, and the obtained circular filter paper is further cut into two halves to obtain two semicircular filter papers. Got The prepared acetone solution of menthyl acetate was added dropwise to one semicircular filter paper (treatment group). Specifically, 1 mL of an acetone solution of menthyl acetate was dropped, and an acetone solution was dropped so that the amount of menthyl acetate was 5 mg per 1 cm ^{2 of} an area of a semicircular filter paper and air-dried. 1 mL of acetone was dropped on the remaining semicircular filter paper and air-dried (untreated section).

As shown in FIG. 1, the filter papers of the treated section 2 and the untreated section 3 were attached to the bottom of the metal dish 1. Next, 10 white lice (female adult) were released into the metal dish 1 and the number of individuals existing in the treated section 2 and the untreated section 3 was counted every 15 minutes. It was carried out until 120 minutes after it was thrown into the metal dish 1. From the counted number of individuals, the repellent rate was calculated using the following formula. The same test was repeated 3 times, and the average value of the repelling rate was calculated 3 times. The results are shown in Table 1. Note that Table 1 shows relative values when the repellent rate of DEET (Comparative Example 1) is 100.
Repelling rate (%)={(untreated area-treated area)/untreated area}×100

(Example 2)
The repellent rate was calculated by the same procedure as in Example 1 except that the acetone solution was added dropwise so that the amount of menthyl acetate in the treated section 2 was 3 mg per 1 cm ² of the semicircular filter paper. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. In addition, Table 1 shows relative values when the repellency of Comparative Example 1 described later is 100.

(Example 3)
The repellent rate was calculated by the same procedure as in Example 1 except that menthyl formate was used instead of menthyl acetate as the repellent component. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. In addition, Table 1 shows relative values when the repellency of Comparative Example 1 described later is 100.

(Example 4)
The repellent rate was calculated by the same procedure as in Example 3 except that the acetone solution was dropped so that the amount of menthyl formate in the treated section 2 was 3 mg per 1 cm ² of the semicircular filter paper. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. In addition, Table 1 shows relative values when the repellency of Comparative Example 1 described later is 100.

(Example 5)
The repellent rate was calculated by the same procedure as in Example 1 except that menthyl propanoate was used instead of menthyl acetate as the repellent component. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. In addition, Table 1 shows relative values when the repellency of Comparative Example 1 described later is 100.

(Example 6)
The repellent rate was calculated by the same procedure as in Example 5 except that the acetone solution was dropped so that the amount of menthyl propanoate in the treated section 2 was 3 mg per 1 cm ² of the semicircular filter paper. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. In addition, Table 1 shows relative values when the repellency of Comparative Example 1 described later is 100.

(Comparative Example 1)
The repellent rate was calculated by the same procedure as in Example 1 except that DEET was used instead of menthyl acetate as the repellent component. The average value of the repellent rate for three times was calculated. In addition, in Table 1, the calculated repellent rate is described as "100".

(Comparative example 2)
As a repellent component, the same procedure as in Example 1 was repeated except that 3-(N-n-butyl-N-acetyl)aminopropionic acid ethyl ester (IR3535, manufactured by Merck) was used instead of menthyl acetate. The rate was calculated. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. Table 1 shows relative values when the repellency rate of Comparative Example 1 is 100.

(Comparative example 3)
The repellent rate was calculated by the same procedure as in Example 1 except that eugenol was used as the repellent component instead of menthyl acetate. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. Table 1 shows relative values when the repellency of Comparative Example 1 is 100.

(Comparative Example 4)
The repellent rate was calculated by the same procedure as in Example 1 except that α-pinene was used as the repellent component instead of menthyl acetate. The average value of the repellent rate for three times was calculated. The results are shown in Table 1. Table 1 shows relative values when the repellency rate of Comparative Example 1 is 100.

As shown in Table 1, Comparative Examples 2 to 4 using IR3535, eugenol or α-pinene, which are conventionally known as various pest repellents, did not have an effective repellent effect against white lice. On the other hand, Examples 1 to 6 using the menthyl ester exhibit a repellent effect that is 20 to 30% higher than DEET having an effective repellent effect against white lice, and the effect is long-lasting. Recognize. Furthermore, since the menthyl acetate used in Examples 1 and 2 does not have the odor like DEET, no unpleasant odor was felt during the repellent test.

1 Metal Petri dish 2 treated area 3 untreated area

Claims (1)

A lice repellent method which comprises treating the menthyl ester represented by the following formula (I) at a place where lice is desired to be repelled so that the treatment amount is at least 3 mg/cm ² .
In formula (I), R represents H or an alkyl group having 1 to 4 carbon atoms.