Insect repellent composition, insect repellent, and insect repellent method

Abstract

To provide a pest repelling composition and a pest repellent which exhibit excellent repelling effect on pests and maintain formulation stability, offering superior usability.SOLUTION: The present invention provides a pest repelling composition and a pest repellent each containing 3-[acetyl(butyl)amino]ethylpropionate and 2-hydroxypropyl-β-cyclodextrin. There is also provided a pest repelling method using the pest repelling composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a pest repellent composition, a pest repellent, and a pest repellent method.

Background Art

[0002] Pests such as mosquitoes, midges, and mites transmit various infectious diseases (for example, malaria, yellow fever, Lyme disease, dengue fever, etc.). Conventionally, by applying a pest repellent, these pests have been repelled, and many pest repellents have been developed. For example, as pest repellent components, those using ethyl 3-[acetyl(butyl)amino]propionate, N,N-diethyl-m-toluamide (DEET), etc. are known. Such pest repellents are usually used by directly applying them to hands, feet, arms, etc., or applying them from above clothes.

[0003] However, the above-mentioned pest repellent components have low solubility in water, resulting in problems with the stability of the formulation, and also problems with the feeling during use such as stickiness when using the pest repellent. Therefore, it has been studied to improve the stability of the formulation and the feeling during use by blending ethanol and other components. For example, Patent Document 1 describes a pest repellent aerosol that contains ethanol as a solvent, contains DEET and monoterpenes, has little stickiness and skin irritation when applied to the human skin surface, has an excellent feeling during use, reduces irritation to the nasal mucosa when atomized by spraying, and has excellent persistence of pest repellent efficacy when applied. Patent Document 2 describes a sanitary pest repellent that contains a specific amount of DEET, essential oil, water, and alcohol (ethanol), does not give a sticky feeling or an unpleasant feeling of roughness to hair, and can repel sanitary pests due to the synergistic effect of DEET and essential oil. Furthermore, since repellents using ethanol can cause irritation during use, Patent Document 3 describes the study of an ethanol-free repellent that is less irritating, stable, comfortable to use, and has excellent retention of the active ingredient, by incorporating a specific surfactant and a specific alcohol into the repellent active ingredient (such as picaridin). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-171703 [Patent Document 2] Japanese Patent Publication No. 2014-201581 [Patent Document 3] Japanese Patent Publication No. 2019-26603 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide an insect repellent composition, an insect repellent agent, and a method of insect repellent using the insect repellent composition that exhibit excellent insect repellent effects and excellent formulation stability, even when incorporating insect repellent components with low water solubility. Furthermore, the object of the present invention is to provide an insect repellent composition, an insect repellent agent, and a method of insect repellent using the insect repellent composition that have excellent usability. [Means for solving the problem]

[0006] The inventors of the present invention conducted diligent studies to solve the above problems and, as a result, discovered a solution consisting of the following configuration, thereby completing the present invention. [1] An insect repellent composition containing ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin. [2] The insect repellent composition described in [1] further contains l-menthol. [3] The insect repellent composition according to [2], wherein the content of 2-hydroxypropyl-β-cyclodextrin relative to the content of l-menthol is 2 to 20 by mass ratio. [4] The insect repellent composition according to any one of the claims [1] to [3], wherein the content of 2-hydroxypropyl-β-cyclodextrin relative to the content of ethyl 3-[acetyl(butyl)amino]propionate is 0.1 to 1 by mass ratio. [5] The insect repellent composition according to any one of [1] to [4], wherein the content of 2-hydroxypropyl-β-cyclodextrin is 1% to 10% by mass. [6] An insect repellent comprising an insect repellent composition described in any one of items (1) to (5). [7] A method for repelling insects using an insect repellent composition described in any one of items [1] to [5]. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an insect repellent composition, an insect repellent agent, and a method of insect repellent using the insect repellent composition that exhibit excellent repellent effects against insects and have excellent formulation stability. Furthermore, it is possible to provide an insect repellent composition, an insect repellent agent, and a method of insect repellent using the insect repellent composition that have excellent usability. [Modes for carrying out the invention]

[0008] The insect repellent composition of the present invention contains ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin.

[0009] Ethyl 3-[acetyl(butyl)amino]propionate has the structure shown in formula (A) below.

[0010] [ka]

[0011] In the insect repellent composition according to the embodiment of the present invention, ethyl 3-[acetyl(butyl)amino]propionate is contained as an insect repellent component.

[0012] The insect repellent composition according to the embodiment of the present invention may further contain insect repellent components other than ethyl 3-[acetyl(butyl)amino]propionate. Examples of insect repellent components that may be further contained include N,N-diethyl-3-methylbenzamide (DEET), 1-methylpropyl ester of 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid, and p-menthane-3,8-diol. Other possible insect repellent components may include essential oil components and extracts of citronellal, citronellol, citral, linalool, terpineol, α-pinene, camphor, geraniol, caran-3,4-diol, peppermint, cedarwood, lavender, tea tree, chamomile, geranium, cinnamon, citronella, lemongrass, clover, bergamot, bay laurel, eucalyptus, etc. Furthermore, the insect repellent components that may be included are, for example, pyrethroid compounds such as acrinatrin, allethrin, beta-cyfluthrin, bifenthrin, cycloprothrin, cyfluthrin, cyhalothrin, cypermethrin, empenthrin, deltamethrin, esfenvalerate, etofenprox, fenpropathrin, fenvalerate, phthalthrin, flucitrinate, flufenprox, flumetrin, fluvalinate, halfenprox, permethrin, prallethrin, pyrethrin, silafluofen, tefluthrin, tralomethrin, transfluthrin, tetramethrin, phenothrin, cyphenothrin, lambda-cyhalothrin, gamma-cyhalothrin, flamethrin, taufluvalinate, metofluthrin, dimefluthrin, mepafluthrin, profluthrin, monfluorothrin, and resmethrin. These insect repellent components other than ethyl 3-[acetyl(butyl)amino]propionate may be present individually or in combination of two or more.

[0013] The content of ethyl 3-[acetyl(butyl)amino]propionate in the pest repellent composition according to an embodiment of the present invention is not particularly limited. In the pest repellent composition according to an embodiment of the present invention, the content of ethyl 3-[acetyl(butyl)amino]propionate is preferably 1% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more. The upper limit of the content of ethyl 3-[acetyl(butyl)amino]propionate is not particularly limited, but is usually about 30% by mass, and preferably 20% by mass or less. By containing ethyl 3-[acetyl(butyl)amino]propionate at such a concentration, a sufficient pest repellent effect is exhibited. When further containing a pest repellent component other than ethyl 3-[acetyl(butyl)amino]propionate, the content thereof is preferably 0.01% by mass to 30% by mass.

[0014] The pest repellent composition according to an embodiment of the present invention needs to contain 2-hydroxypropyl-β-cyclodextrin. 2-Hydroxypropyl-β-cyclodextrin is a cyclic oligosaccharide that can be used as an inclusion compound that includes a poorly soluble substance and dissolves it in a solvent. By containing 2-hydroxypropyl-β-cyclodextrin, the pest repellent composition according to an embodiment of the present invention can dissolve ethyl 3-[acetyl(butyl)amino]propionate, which has low solubility in water, in water, and has excellent stability of the preparation. Known means can be used for the method of including ethyl 3-[acetyl(butyl)amino]propionate with 2-hydroxypropyl-β-cyclodextrin. For example, there is a method of gradually adding ethyl 3-[acetyl(butyl)amino]propionate while stirring a slurry or an aqueous solution of ethyl 3-[acetyl(butyl)amino]propionate.

[0015] The pest repellent composition according to an embodiment of the present invention may further contain an inclusion compound other than 2-hydroxypropyl-β-cyclodextrin. The inclusion compound that can be further contained is not particularly limited. For example, cyclic oligosaccharides such as cyclodextrins such as α-cyclodextrin, β-cyclodextrin other than 2-hydroxypropyl-β-cyclodextrin, and γ-cyclodextrin can be mentioned.

[0016] The content of 2-hydroxypropyl-β-cyclodextrin in the pest repellent composition according to an embodiment of the present invention is not particularly limited. In the pest repellent composition according to an embodiment of the present invention, the content of 2-hydroxypropyl-β-cyclodextrin is preferably 0.1% by mass or more, more preferably 1% by mass or more, and still more preferably 2% by mass or more. The upper limit of the content of 2-hydroxypropyl-β-cyclodextrin is not particularly limited, but is usually about 20% by mass, preferably 10% by mass or less, and more preferably 5% by mass or less. In the pest repellent composition according to an embodiment of the present invention, the content of 2-hydroxypropyl-β-cyclodextrin is preferably 1% to 10% by mass. The content ratio of 2-hydroxypropyl-β-cyclodextrin to the content of ethyl 3-[acetyl(butyl)amino]propionate is preferably 0.1 to 1, more preferably 0.1 to 0., and still more preferably 0.2 to 0.3 in terms of mass ratio.

[0017] By containing 2-hydroxypropyl-β-cyclodextrin at such a concentration, ethyl 3-[acetyl(butyl)amino]propionate can be dissolved in water, and sufficient stability of the preparation can be obtained. When further containing an inclusion compound other than 2-hydroxypropyl-β-cyclodextrin, the content is preferably 0.01% to 1% by mass.

[0018] In addition to ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin, the insect repellent composition according to the embodiment of the present invention may further contain l-menthol as an optional component. As described above, the insect repellent composition according to the embodiment of the present invention dissolves ethyl 3-[acetyl(butyl)amino]propionate, which is poorly soluble in water, in water by encapsulating it with 2-hydroxypropyl-β-cyclodextrin. Since 2-hydroxypropyl-β-cyclodextrin has thickening properties, insect repellents containing an insect repellent composition formulated with 2-hydroxypropyl-β-cyclodextrin may become sticky after the solvent evaporates when applied directly to the skin or hair. However, by incorporating l-menthol, the stickiness caused by 2-hydroxypropyl-β-cyclodextrin can be reduced, resulting in an insect repellent with a superior feel.

[0019] The l-menthol content in the insect repellent composition according to the embodiment of the present invention is not particularly limited. The l-menthol content in the insect repellent composition according to the embodiment of the present invention is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more. There is no particular upper limit to the l-menthol content, but from the viewpoint of suppressing irritation, it is preferably 10% by mass or less, and more preferably 5% by mass or less. The content of 2-hydroxypropyl-β-cyclodextrin relative to the l-menthol content is preferably 2 to 20 by mass, more preferably 2 to 10, and even more preferably 2 to 6.

[0020] In addition to the above components, the insect repellent composition according to the embodiment of the present invention may further contain optional components, to the extent that they do not inhibit the effects of the present invention. For example, optional components include solvents, nonionic, anionic or cationic surfactants, antioxidants such as butylhydroxytoluene; stabilizers such as citric acid and ascorbic acid; inorganic powders such as talc and silicic acid, disinfectants, fungicides, deodorizers, fragrances, dyes, ultraviolet absorbers, chelating agents, retainers, pH adjusters, thickeners, etc.

[0021] If a solvent is included, the type of solvent is not particularly limited. For example, solvents include water, ethanol, lower alcohols such as isopropyl alcohol, isopropyl myristate, propylene glycol, butylene glycol, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol diacetate, normal paraffin, isoparaffin, glycerin, etc. Solvents may be used in combination. Among these, water is preferred as the solvent because it can sufficiently dissolve the insect repellent component and prevents irritation during use. Furthermore, from the viewpoint of preventing irritation during use and obtaining a pleasant user experience, it is preferable not to include lower alcohols such as ethanol and isopropyl alcohol.

[0022] If a solvent is included, the solvent content is not particularly limited, but it is preferable that the solvent be added such that, for example, the concentration of a specific insect repellent component is 5% by mass or more. For example, the solvent content is preferably 50% by mass or more, and more preferably 60% by mass or more, in the insect repellent composition. Furthermore, the solvent content is preferably 95% by mass or less, and more preferably 90% by mass or less, in the insect repellent composition. When the solvent content is within the above range, the insect repellent composition can sufficiently dissolve the insect repellent component and easily exhibit an excellent insect repellent effect.

[0023] The method for producing the insect repellent composition according to the embodiment of the present invention is not particularly limited. For example, the above-mentioned ethyl 3-[acetyl(butyl)amino]propionate, 2-hydroxypropyl-β-cyclodextrin, and optionally a solvent or additive may be mixed and stirred to dissolve the ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin in the solvent.

[0024] The insect repellent composition according to the embodiment of the present invention can be used as an insect repellent. The insect repellent according to the embodiment of the present invention may contain the above-mentioned insect repellent composition. The insect repellent composition according to the embodiment of the present invention can be used in an insect repellent method. The method of use of the insect repellent according to the embodiment of the present invention is not particularly limited, and its dosage form is not particularly limited. For example, the insect repellent may be a liquid formulation containing the above-mentioned insect repellent composition as is. If the insect repellent according to the embodiment of the present invention is a liquid formulation, the insect repellent can be applied by impregnating a suitable cloth or the like and wiping the area to be applied. Furthermore, insect repellents may be formulated by adding the above-mentioned optional components to the insect repellent composition during the formulation process. For example, by incorporating optional components such as surfactants and gelling agents, they can be formulated into emulsions, gels, pastes, aerosols, pumps, etc.

[0025] When formulated as an aerosol, the insect repellent composition according to the present invention and a propellant can be sealed in an aerosol can for use. On the other hand, when used in spray form, the insect repellent composition according to the present invention can be sealed in a container such as a hand sprayer for use. Examples of propellants include liquefied gases and compressed gases. Examples of liquefied gases include liquefied petroleum gas, dimethyl ether, hydrofluoroolefins, and difluoromonochloroethanes. Examples of compressed gases include carbon dioxide, nitrogen gas, and compressed air. In both aerosol and spray forms, the average particle size of the mist-like droplets is not particularly limited. For example, the 50% average particle size at a distance of 30 cm from the nozzle is approximately 10 to 1000 μm. When formulated as an aerosol or pump-type insect repellent, it can be used by spraying an appropriate amount onto the application area. For example, it is typically used by spraying it onto the hands, feet, arms, or clothing.

[0026] Thus, by using an insect repellent composition containing ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin, the ethyl 3-[acetyl(butyl)amino]propionate can be solubilized in a solvent, stabilizing the formulation and allowing the insect repellent to be sprayed without problems. Furthermore, by solubilizing ethyl 3-[acetyl(butyl)amino]propionate without adding ethanol, irritation from the insect repellent sprayed in mist form can be prevented. In addition, in a preferred embodiment, the addition of l-menthol can prevent stickiness and result in an insect repellent with a superior user experience.

[0027] The types of target pests that the insect repellent composition of this embodiment targets are not particularly limited. Target pests include, for example, pests that inhabit indoors and outdoors, such as house mosquitoes such as Culex pipiens, Culex tropicalis, Culex tritaeniorhynchus, Culex tritaeniorhynchus, Culex pipiens, Culex tritaeniorhynchus, Culex pipiens, Culex leucocephala, Culex leucocephala, Culex serrata, Culex serrata, Aedes mosquitoes such as Aedes albopictus, Aedes aegypti, Aedes japonica, Aedes leucocephala, Aedes japonica, Culex serrata Examples include blood-sucking and biting insects such as flies, fleas, lice, bed bugs, assassin bugs, ticks, chiggers, and leeches; midges such as Chironomidae, Chironomidae, Chironomidae, Chironomidae, and Chironomidae; cockroaches such as German cockroaches, American cockroaches, Common cockroaches, Japanese cockroaches, and brown cockroaches; flies; ants such as Pheidole ants, Black garden ants, Brown wrinkled ants, and Reticulated ants; termites; wasps; house centipedes; rice weevils, confused flour beetles, cigarette beetles, carpet beetles, and varied carpet beetles, which are stored grain pests. Blood-sucking and biting insects are particularly suitable.

[0028] As described above, the insect repellent composition of this embodiment, by containing ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin, exhibits excellent repellent effects against insects and maintains the stability of the formulation. Furthermore, it has a low irritation and a pleasant feel to use. [Examples]

[0029] 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.

[0030] (Example 1) 10 g of ethyl 3-[acetyl(butyl)amino]propionate and 1 g of 2-hydroxypropyl-β-cyclodextrin were mixed. Purified water was added to the resulting mixture so that the total volume of the preparation became 100 g, and the mixture was stirred to prepare Sample 1. The concentration of the insect repellent component in Sample 1 was 10% by mass.

[0031] (Example 2) 10 g of ethyl 3-[acetyl(butyl)amino]propionate, 1 g of 2-hydroxypropyl-β-cyclodextrin, and 0.5 g of l-menthol were mixed. Purified water was added to the resulting mixture so that the total volume of the preparation became 100 g, and the mixture was stirred to prepare sample 2. The concentration of the insect repellent component in sample 2 was 10% by mass.

[0032] (Examples 3-11) Samples 3 to 11 were prepared using the same procedure as in Example 1 or 2, except that the amounts of 2-hydroxypropyl-β-cyclodextrin and l-menthol were changed as shown in Table 1.

[0033] (Comparative example) A comparative example sample was prepared by adding purified water to 10 g of ethyl 3-[acetyl(butyl)amino]propionate until the total volume reached 100 g, and then stirring. The concentration of the insect repellent component in the comparative example sample was 10% by mass.

[0034] Next, the solubility of samples 1 to 11 obtained in Examples 1 to 11 and Comparative Examples, as well as the comparative example sample, was evaluated. Furthermore, the feel (irritation, stickiness) of samples 1 to 11 was evaluated. In the comparative example sample, ethyl 3-[acetyl(butyl)amino]propionate did not dissolve in water, making it impossible to evaluate the feel.

[0035] (Solubility) Samples 1-11 and the comparative example were sealed in glass bottles and left to stand for 24 hours. After that, their appearance was evaluated according to the following criteria. <Standards> ○: When distributed. ×: When separated.

[0036] (Feeling of use (stimulation)) Samples 1-11 were each sealed in a hand spray bottle (single spray volume: approximately 0.3 mL). Ten panelists (five men and five women) were each sprayed once from the hand spray bottle onto their shoulders from a distance of 15 cm from the front. The ten panelists evaluated the irritation they felt after spraying according to the following criteria. All samples from 1-11 were non-irritating, and the result was ○. <Standards> ○: When little or no sensation was felt. △: If you feel a slight irritation that is not noticeable in practical use. ×: If you feel a stimulating sensation.

[0037] (Feeling of use (stickiness)) Samples 1-11 were each sealed in a hand spray bottle (single spray volume: approximately 0.3 mL). Ten male and female panelists sprayed the sealed sample once onto their forearms from a distance of 15 cm from the front. The ten panelists evaluated the stickiness they felt after spraying according to the following criteria. The results are shown in Table 1. <Standards> 5. If you did not feel any stickiness. 4. If you didn't feel much stickiness. 3: When you can't say whether you felt sticky or not. 2: If you feel it is slightly sticky. 1: If you feel stickiness.

[0038] [Table 1]

[0039] As shown in Table 1, samples 1 to 11 obtained in Examples 1 to 11 exhibited excellent solubility and low irritancy. Even when ethyl 3-[acetyl(butyl)amino]propionate, which is poorly soluble in water, was added, there were no problems with solubility, indicating that the stability of the formulation was maintained. Furthermore, because it does not contain alcohol such as ethanol, it is less likely to cause irritation and has a superior feel. In addition, Examples 2, 4, 6, and 8, which contained l-menthol, were less sticky than Examples 1, 3, 5, and 7, which did not contain l-menthol. Furthermore, Examples 4 and 9-11, which contained 0.1g to 0.5g of l-menthol, were found to be less sticky and have a superior feel compared to Example 3.

Claims

1. It contains ethyl 3-[acetyl(butyl)amino]propionate and 2-hydroxypropyl-β-cyclodextrin, Furthermore, it contains l-menthol, The content of 2-hydroxypropyl-β-cyclodextrin relative to the content of l-menthol is 2 to 20 by mass, An insect repellent composition that does not contain ethanol or isopropyl alcohol.

2. The insect repellent composition according to claim 1, wherein the content of 2-hydroxypropyl-β-cyclodextrin relative to the content of ethyl 3-[acetyl(butyl)amino]propionate is 0.1 to 1 by mass ratio.

3. The insect repellent composition according to claim 1 or 2, wherein the content of 2-hydroxypropyl-β-cyclodextrin is 1% by mass to 10% by mass.

4. An insect repellent comprising the insect repellent composition described in claim 1 or 2.

5. A method for repelling insects using the insect repellent composition described in claim 1 or 2.

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