JP7257354B2 - How to avoid lice - Google Patents

Description

TECHNICAL FIELD The present invention relates to a louse repelling method capable of continuously repelling lice.

Human lice include body lice (eg, head lice, body lice, etc.) and pubic lice. Among these lice, the infestation rate of head lice has been increasing in recent years, and the damage to kindergarteners and children who live in groups is particularly remarkable. In addition, transmission from kindergarteners and children to family members has been reported.

Head lice live on human hair and survive by sucking blood from the scalp. Therefore, when parasitized by head lice, the scalp is accompanied by strong itching due to blood sucking. In addition, blood-sucking or intensely itchy scratches can become infected with bacteria or viruses, which can lead to infections, swollen lymph nodes, and fever.

Conventionally, in order to prevent such lice damage, a method of using a shampoo containing a pyrethroid compound on the hair infested with lice to exterminate them has been generally performed (Patent Document 1). However, extermination using shampoo is a method for exterminating already parasitized lice, and a certain amount of time is required until extermination. Therefore, until the lice are exterminated, it is impossible to avoid damage such as the strong itching described above.

Therefore, it is preferable to prevent the infestation of lice rather than to exterminate the infested lice. However, lice are pests that are difficult to control, and at present, repellents for lice have hardly been studied. Under such circumstances, Patent Document 2 describes that N,N-diethyl-m-toluamide (DEET) is effective as a louse repellent component. However, since DEET has a peculiar odor, the odor poses a problem when used. Therefore, in order to use DEET, it must be used together with a masking agent to alleviate discomfort during use, and its repellent effect is not sufficient.

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

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

式（Ｉ）中、Ｒは、Ｈまたは炭素数が１～４個のアルキル基を示す。 As a result of intensive studies conducted by the present inventors to solve the above problems, the inventors have found a means for solving the problems described below, and have completed the present invention.
(1) A method for repelling lice, which comprises applying a menthyl ester represented by the following formula (I) to a portion where lice are to be repelled so that the treated 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 repelling method of the present invention, lice can be continuously repelled.

FIG. 4 is an explanatory diagram for explaining a contact repelling test method performed in Examples.

The louse repellent of the present invention contains menthyl ester as an active ingredient. A 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 louse repellent of the present invention is not particularly limited, and has, for example, the structure shown in formula (I) below.

R in formula (I) represents H or an alkyl group having 1 to 4 carbon atoms. Among these, R is preferably H, methyl group or ethyl group. When R is a methyl group, the menthyl ester is menthyl acetate represented by the following formula (II), when R is H, it is menthyl formate, and when R is an ethyl group, it is menthyl propanoate. Menthyl esters are easily metabolized and decomposed when in contact with or inhaled by the human body, and are highly safe. It also has the characteristic of providing a refreshing feeling when applied to the human body.

Furthermore, in consideration of usability, excipients may be used as long as they do not impair the effects of the present invention. Excipients are appropriately selected according to the desired dosage form. For example, when preparing a liquid louse repellent, excipients include water, alcohols (e.g., ethanol, glycerin, etc.), polyols such as polyalkylene glycol, their ethers, and solvents such as glycol ethers. used. A liquid formulation may be prepared by dissolving or suspending the menthyl ester in these solvents. On the other hand, when preparing a solid louse repellent, excipients used include polyols such as polyalkylene glycol and their ethers, starch, dextrin, lactose, resins, inorganic powders, pulp and the like.

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

Furthermore, the louse repellent of the present invention may optionally contain fragrances, antioxidants, deodorants, pigments, chelating agents, surfactants, retention agents, pH adjusters, bactericides, antifungal agents, and the like. Additives may be included.

The dosage form of the louse repellent of the present invention is not particularly limited. The louse repellent of the present invention may be a liquid formulation or a solid formulation 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 applied to a location where lice are desired to be repelled. The treatment amount is not particularly limited, and in order to efficiently repel lice, the treatment amount of menthyl ester is preferably at least 3 mg/cm ² , more preferably at least 5 mg/cm ² . The type of lice repelled by the louse repellent of the present invention is not particularly limited, and examples thereof include head lice, body lice, and pubic lice.

A place where it is desired to avoid lice, that is, an object to be treated with the repellent of the present invention includes, for example, what is thought to be an infection route of lice. Specific examples of objects to be treated include clothes, bedding (pillows, blankets, etc.), towels, bath towels, baskets for undressing, hairbrushes, etc., and are appropriately selected according to the type of lice to be repelled. Alternatively, the human body such as hair is also included in the treatment target, and can be applied directly to the human body.

When the louse repellent agent of the present invention is used as a liquid agent, it may be used as it is, for example, in the form of a spray or an aerosol. Propellants used in aerosol form include, for example, 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 liquid agent onto the object to be treated, 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 dressing or treatment.

On the other hand, when the louse 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 chest of drawers together with clothes, towels, bath towels, etc. Well, you can put it in your pillow or futon. Alternatively, a bag containing the repellent may be sewn onto the lining of clothing or the like. Furthermore, in the case of dust, it may be sprayed directly on the object to be treated.

For example, in the case of head lice, lice adhere to towels, bath towels, hairbrushes, pillows, etc. used by an infected person, and other people use these towels with lice adhered to the infected person. Therefore, by treating these towels with the lice repellent agent of the present invention, even if lice adhere to the towels, the lice will be repelled, so that the towels will be free of lice.

EXAMPLES The present invention will be specifically described below 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 of appropriate concentration. Next, a filter paper (manufactured by Advantech Toyo Co., Ltd., product number: 00021150) is cut into a circle with a diameter of 9 cm, and the obtained circular filter paper is further cut in half to obtain two semicircular filter papers. got The prepared acetone solution of menthyl acetate was dropped onto one of the semicircular filter papers (treated area). Specifically, 1 mL of an acetone solution of menthyl acetate was dropped, and the acetone solution was dropped so that the amount of menthyl acetate was 5 mg per 1 cm ² of the area of the semicircular filter paper, followed by air drying. 1 mL of acetone was dropped on the remaining semicircular filter paper and air-dried (untreated area).

As shown in FIG. 1, the filter papers of the treated area 2 and the untreated area 3 were attached to the bottom of a metal petri dish 1, respectively. Then, 10 body lice (female adults) were released into the metal petri dish 1, and the number of individuals present in the treated area 2 and the untreated area 3 was counted every 15 minutes. After leaving in the metal Petri dish 1, it continued until 120 minutes later. From the number of individuals counted, the repellency rate was calculated using the following formula. A similar test was repeated 3 times, and the average value of the 3 repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repellency rate of DEET (Comparative Example 1) is set to 100.
Repellent rate (%) = {(untreated area - treated area) / untreated area} x 100

(Example 2)
The repellency rate was calculated in the same manner as in Example 1, except that the acetone solution was added dropwise so that the amount of menthyl acetate in treated area 2 was 3 mg per 1 cm ² area of the semicircular filter paper. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 described later is set to 100.

(Example 3)
The repellency rate was calculated in the same manner as in Example 1, except that menthyl formate was used as the repellent component instead of menthyl acetate. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 described later is set to 100.

(Example 4)
The repellency rate was calculated in the same manner as in Example 3, except that the acetone solution was added dropwise so that the amount of menthyl formate in treated area 2 was 3 mg per 1 cm ² area of the semicircular filter paper. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 described later is set to 100.

(Example 5)
The repellency rate was calculated in the same manner as in Example 1, except that menthyl propanoate was used instead of menthyl acetate as the repellent component. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 described later is set to 100.

(Example 6)
The repellency rate was calculated in the same manner as in Example 5, except that the acetone solution was dropped so that the amount of menthyl propanoate in treated area 2 was 3 mg per 1 cm ² area of the semicircular filter paper. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 described later is set to 100.

(Comparative example 1)
The repellency rate was calculated in the same manner as in Example 1, except that DEET was used as the repellent component instead of menthyl acetate. An average value of three repellency rates was obtained. In addition, in Table 1, the calculated repelling rate is described as "100".

(Comparative example 2)
Repellent was applied in the same manner as in Example 1, except that 3-(Nn-butyl-N-acetyl)aminopropionic acid ethyl ester (IR3535, manufactured by Merck) was used as the repellent component instead of menthyl acetate. rate was calculated. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 is set to 100.

(Comparative Example 3)
The repellency rate was calculated in the same manner as in Example 1, except that eugenol was used as the repellent component instead of menthyl acetate. An average value of three times of repellency was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 is set to 100.

(Comparative Example 4)
The repellency rate was calculated in the same manner as in Example 1, except that α-pinene was used as the repellent component instead of menthyl acetate. An average value of three repellency rates was obtained. Table 1 shows the results. Table 1 shows relative values when the repelling rate of Comparative Example 1 is set to 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 body lice. On the other hand, Examples 1 to 6 using menthyl ester exhibited a 20 to 30% higher repellent effect than DEET, which has an effective repellent effect against body lice, and the effect lasted for a long time. Recognize. Furthermore, since the menthyl acetate used in Examples 1 and 2 did not have an odor like DEET, no unpleasant odor was perceived during the repellency test.

1 metal petri dish 2 treated area 3 untreated area

Claims (1)

A method for repelling lice, which comprises applying a menthyl ester represented by the following formula (I) to a place where lice are to be repelled in an amount of at least 3 mg/cm ² .

In formula (I), R represents H or an alkyl group having 1 to 4 carbon atoms.

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