WO2011030122A2

WO2011030122A2 - Insect repellent: project fabric shield

Info

Publication number: WO2011030122A2
Application number: PCT/GB2010/051430
Authority: WO
Inventors: Andrew Martin Scrivener
Original assignee: Reckitt & Colman (Overseas) Limited
Priority date: 2009-09-09
Filing date: 2010-08-31
Publication date: 2011-03-17
Also published as: WO2011030122A3; GB0915703D0

Abstract

Animal pest repellent compositions and methods are disclosed that are particularly suitable for repelling flying insects such as mosquitoes. The compositions utilise very low concentrations of vapour active pyrethroid such a transfluthrin and metofluthrin dissolved in a carrier solvent such as ethanol. These compositions are sprayed onto a defined surface area of the clothing of an individual. The amount of vapour active pyrethroid and surface area covered may be varied according to the extent of effective repellency required. Advantageously, the vapour active pyrethroid need not be sprayed onto the skin in order to obtain a desirable level of protection.

Description

"Insect repellent: Project Fabric Shield"

Field of the Invention

This invention relates to compositions and methods utilising vapour active pyrethroids for repelling insects as well as other animals such as leeches, ticks and mites are regarded as pests towards humans.

Background to the Invention

There are a number of species of animals, particularly insects such as mosquitoes, flies and ants that bite humans and other animals. At the very least in some cases such bites are irritant. In other instances, even when not bitten, the constant buzzing of mosquitoes may deprive or reduce the ability of an individual to sleep soundly. Even in outdoor situations such as fishing, hiking and the like, the constant physical presence of mosquitoes buzzing around an individual is annoying. Of course, insects such as mosquitoes may be the vector for diseases which in the case of malaria, dengue fever and the like can be fatal to humans.

Whilst other flying pests such as biting midges, sand flies, black flies, house flies, bush flies, march flies, horse flies bees, wasps, may not necessarily be the vector for disease, they may still bite or sting and are generally irritating when in the presence of humans. This is also relevant to other pest species such as ants, cockroaches, leeches, ticks and mites. In this regard it will be noted that whilst these species are not flying insects and don't buzz, in the case of ants, leeches, ticks and mites they bite. Furthermore they may be disease vectors such as in the case of ticks or they may carry microorganisms such as bacteria in the case of cockroaches. In addition it should be noted that some people regard contact with such animal species as being an unpleasant experience. Such people would therefore regard effective repellency as quite beneficial. It is therefore desirable to be able to at least prevent biting by these species and preferably to be able to repel such species to an extent sufficient to reduce or eliminate there pest potential.

In the art a variety of approaches has been used against such pest species. Broadly these approaches comprise physical barriers, pesticidal compositions repellent compositions. The physical barrier is typified by devices such as the mosquito net, which in some cases may be impregnated with an insecticide. Such barriers are quite effective at preventing biting when an individual is sleeping but are of course impractical for all other circumstances when mosquitoes might be encountered. Another alternative is the insecticide which may take a variety of compositional forms. These forms include aerosol sprays, combustible mosquito coils and electrical driven devices for emanating insecticide into the atmosphere. All of these forms rely upon providing an effective amount of an insecticide into the atmosphere with the aim of ridding a defined space of the pest species. Whilst these forms are particularly effective in controlled spaces such as a room when entry of the pest species is prevented, they are of limited effectiveness in an outdoor environment or indeed any space where entry of the pest species may not be prevented.

Finally, compositions based on, for example, active repellent substances such as N,N-Diethyl-m-toluamide (DEET) are effective in repelling a range of flying insects such as mosquitoes and various flies. However, the compositions must be applied to the skin and clothing of individuals in order to be effective. Furthermore, the range of effective protection provided is such that an individual will both be able to hear a buzzing insect and physically perceive the presence of the insect. So whilst biting by the insect may be prevented, insects such as mosquitoes will still be visible and annoying. In addition, there is a growing concern amongst users that it is undesirable to apply such compositions to the skin for reason of perceived potential toxicity. This is particularly relevant in situations where repeated application is required. An example being a room where entry of the pest species cannot be prevented. Sleeping in such a room would require the daily application of the repellent composition.

It is therefore evident that there exists a need that may be used as a repellent against a wide range of animal pest species that is effective to not only prevent biting, but in the case of flying buzzing insects to repel the species sufficiently from an individual such that the buzzing and the physical presence of the species is no longer evident to the individual. Desirably, such a repellent need not be applied to the skin in order to be effective.

Summary of the Invention It has been discovered by the present inventors that vapour active pyrethroids when applied to quite small areas of clothing in very low concentration function as effective repellents against mosquitoes. Such functionality is quite unexpected given that typically such vapour active pyrethroids require a certain energy input so as to create an effective atmospheric concentration.

Accordingly, in one aspect, the present invention consists in a method of repelling a pest species selected from the group consisting of mosquitoes, midges, flies, bees, wasps, ticks, mites, leeches, cockroaches and ants from a region around a clothed person, the method comprising applying sufficient of a composition, containing a vapour active pyrethroid in which the vapour active pyrethroid is dissolved in a carrier solvent, to an area of the clothes of at least 100 cm and allowing the solvent to evaporate so that at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

In another aspect, the present invention consists in the use of a composition, which comprises a vapour active pyrethroid dissolved in a carrier solvent, to repel a pest species selected from the group consisting of mosquitoes, midges, flies, ticks, mites, leeches, cockroaches and ants from a region around a clothed person in which sufficient of the composition is applied to an area of at least 100 cm of the clothes so that upon evaporation of the solvent, at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

In a further aspect, the present invention consists in a package for repelling a pest species selected from the group consisting of mosquitoes, midges, flies, bees, wasps, ticks, mites, leeches, cockroaches and ants from a region around a clothed person, the package comprising means to eject a composition contained therein as a spray adapted for application to an area of at least 100 cm of the clothes so that upon evaporation of a carrier solvent for a vapour active pyrethroid, both of which are included in the composition, at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

Disclosure of the Invention It will evident that the present invention offers a number of advantages over the prior art repellents. In particular, it is not necessary to apply the inventive composition to the skin. Rather, a relatively small amount is applied to a relatively small area of clothing. The result of application of the inventive composition is that pest species, such as mosquitoes, are effectively repelled to an extent sufficient such that there physical presence is not perceived either visually or aurally whilst of course not landing on an individual.

Typically, the extent of repellency achieved will create a region around an individual so the pest species approaches no closer then a distance of 10 cm away from the individual. Preferably, the distance achieved will be 20 cm, most preferably 50 cm up to a distance of 100 cm. As used in the specification the term "vapour active pyrethroid" refers to a pyrethroid which is preferably selected from the group consisting of metofluthrin, transfluthrin, empenthrin, methothrin, tefluthrin, profluthrin and fenfluthrin or mixtures thereof. The most preferred pyrethroids are metofluthrin or transfluthrin, particularly transfluthrin.

Preferably the carrier solvent has an evaporation rate according to ASTM D3539-87 of less than approximately 1.0 and a boiling point in the range of approximately 33-330°C. Most preferably the carrier solvent has a boiling point in the range of from about 50-265°C.

The carrier solvent may be selected from, but not limited to, chlorinated hydrocarbons (e.g. 1,1,1-trichloroethane, dichloromethane, chloroform); alcohols (e.g. methanol, ethanol, n-propanol); ketones; alcohol and ketone mixtures (e.g. acetone/ethanol (1: 1 by volume); normal paraffins with a boiling point range of about 155-276°C (e.g. Norpar 12); dearomatised aliphatic hydrocarbons and their blends in the boiling point range of about 33-265°C (e.g. pentane, heptane, hexane, Exxsol D40, Exxsol D80 and Exxsol D100); isoparaffins in the boiling point range of about 150- 300°C (e.g. Isopar G, and Isopar M); glycol ethers in the boiling point range of about 120-243°C; natural or synthetically derived aroma chemicals, preferably in the boiling point range of approximately 120-250°C (e.g. monoterpenes and sesquiterpenes, including monoterpene and sesquiterpene alcohols, aldehydes, ketones, esters, oxides and hydrocarbons such as linalool, geraniol, citronellal, citral, geranial, menthone, linalyl acetate, bornyl acetate, 1,8-cineole and limonene); and essential oils. Exxsol, Norpar and Isopar are trade marks of Exxon.

Typically the carrier solvent will be included in the compositions of the invention in an amount in the range of from 10-99.98% w/v, preferably , most preferably

It will of course be appreciated that the solvent must be compatible with a wide range of fabrics from which clothes are made. Preferred carrier solvents are the lower molecular weight alcohols such as ethanol.

It is within the scope of the invention that the carrier solvent consists of a mixture of solvents. Generally, the mixture will be constituted by two solvents where the co-solvent is included at a concentration of >0-30% w/v, preferably >0-10% w/v, most preferably >0-5% w/v.

Preferred co- solvents include d- limonene, normal paraffins with a boiling point range of about 155-276°C (e.g. Norpar 12); dearomatised aliphatic hydrocarbons and their blends in the boiling point range of about 33-265°C (e.g. pentane, heptane, hexane, Exxsol D40, Exxsol D80 and Exxsol D100); and isoparaffins in the boiling point range of about 150-300°C (e.g. Isopar G, and Isopar M). Particularly preferred are d-limonene and C₁₀-C₁₃ n-paraffins.

Water may be optionally included in the compositions of the invention in an amount of 1-90% w/v, preferably 10-80% w/v, most preferably 20-70% w/v. For example, water may be combined with carrier solvents such as ethanol with which it is miscible or it may be included to form an emulsion with immiscible carrier solvents such as isoparaffins. When emulsion compositions are formed, desirably these will include one or more emulsifiers typically in a concentration of about 1-10 times the concentration of vapour active pyrethroid. Therefore, the emulsifiers may be incorporated at a concentration of 0.1-30% w/v, preferably 0.2-20% w/v, most preferably 0.3-10% w/v. As used in this specification, "emulsion" includes a reference to "microemulsion".

The emulsifiers that may be used include polyglycerol oleate esters, Microflex NX and Microflex 1 (Microflex is registered trade mark of International Speciality Products) and Teric, for example Teric LA8N (Teric is a registered trade mark of Huntsman).

At least 0.2 mg of vapour active pyrethroid is deposited on area of clothing of at least 100 cm . The amount deposited may be increased so as to provide more effective repellency. By "more effective" it is meant that the length of time that repellency is provided may be increased. Alternatively under higher ambient temperature conditions, a greater amount of vapour active pyrethroid may need to be deposited.

For example vapour active pyrethroid may preferably be deposited in amounts of 1 mg or more, 2 mg or more, 5 mg or more, 10 mg or more, 25 mg or more, 50 mg or more, 100 mg or more. Generally, the maximum amount deposited would be up to about 200 mg. Suitable ranges of amounts deposited of the vapour active pyrethroid may be selected in amounts of from 0.2-200 mg, 0.2-100 mg, 0.2-50 mg, 0.2-25 mg, 0.2-10 mg. 0.2-5 mg, 0.2-2 mg, 2-200 mg, 2-100 mg, 2-50 mg, 2-25 mg, 2-10 mg, 2-5 mg, 5-200mg, 5-100 mg, 5-50 mg, 5-25 mg, 5-10 mg, 10-200 mg, 10-100 mg, 10-50 mg, 10-25 mg, 25-200 mg, 25-100 mg and 25-50 mg.

Alternatively or in addition, the surface area to which the vapour active pyrethroid is deposited may be increased. For example, the area onto which the vapour active pyrethroid may be preferably deposited comprises 200 cm 2 or more, 500 cm 2 or more, 1,000 cm 2 or more, 3,000 cm 2 or more, 6,000 cm 2 or more, 10,000 cm 2 or more. Generally the maximum surface area onto which the vapour active pyrethroid will be deposited will be 15,000 cm . Suitable ranges of surface areas for deposition may selected from 100-15,000 cm², 200-15,000 cm², 500-15,000 cm², 1,000-15,000 cm², 3,000-15,000 cm², 6,000-15,000 cm², 10,000-15,000 cm², 100-10,000 cm², 200-10,000 cm², 500-10,000 cm², 1,000-10,000 cm², 3,000-10,000 cm², 6,000-10,000 cm²,

100-6,000 cm², 200-6,000 cm², 500-6,000 cm², 1,000-6,000 cm², 3,000-6„000 cm², 100-3,000 cm², 200-3,000 cm², 500-3,000 cm², 1,000-3,000 cm²,

100-1,000 cm², 200-1,000 cm², 500-1,000 cm², 100-500 cm², 100-200 cm², and 200- 500 cm².

Typically, it is possible to obtain repellencies of at least 50% landing inhibition for at least 2 hours, preferably, 60% landing inhibition for at least 4 hours, more preferably 70% landing inhibition for at least 6 hours, most preferably 80% landing inhibition for at least 8 hours.

In this specification, it is to be understood that effective repellency requires a minimum landing inhibition of 40% for at least 2 hours.

A wide range of concentrations of vapour active pyrethroid in the carrier solvent may be provided. The concentration will be determined by the amount required to be deposited, it being recognised that the volume of solvent ought not to be so great as to unduly wet the fabric to which it is applied. Typical concentrations will be in the range of 0.02 to 10% w/v, preferably 0.1 to 5% w/v, most preferably 0.2 to 2.0% w/v.

The package aspect of the invention comprises means to eject a composition contained therein as a spray adapted for application to an area of at least 100 cm of the clothes so that upon evaporation of a carrier solvent for a vapour active pyrethroid, both of which are included in the composition, at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

Broadly, the package may comprise a pump type spray or an aerosol package. In the case of the pump type spray, the composition may comprise vapour active pyrethroid dissolved in a solvent with no other ingredients necessarily being required. However, it should be noted that in addition to the carrier solvent and vapour active pyrethroid, to enhance consumer acceptance, a fragrance may be added typically in a concentration up to about 10% w/v. In addition, preservatives and antioxidants such as butylated hydroxtoluene may be included in a concentration of up to about 2% w/v. Given the relative low viscosity of these compositions, a wide range of pump type sprays known in the art may be used. For example, the container for the composition may comprise a high density polyethylene bottle and a pump assembly formed of a polypropylene housing and dip tube and a high density polyethylene actuator, the pump dispensing a volume of 180 microlitres per stroke. In the case of an aerosol package, a typical composition will comprise vapour active pyrethroid, a fragrance may be in a concentration up to about 10% w/v, preservatives and antioxidants such as butylated hydroxtoluene or sodium benzoate in a concentration of 0.0001% up to about 10% w/v, a propellant, such as butane in a concentration of about 10-90% w/v, with the balance being carrier solvent. Preferably the butylated hydroxtoluene or sodium benzoate is in a concentration of 0.0005-5% w/v, most preferably 0.001-2% w/v. Preferably the propellant is in a concentration of 15-80% w/v, most preferably 20-70% w/v. Particularly preferred is a concentration of about 30% w/v of propellant.

A typical aerosol package comprises a 52 mm diameter tinplate can, preferably lacquered internally, with a 162 mm length and a 150 mL nominal fill capacity. The valving arrangement comprises a 25.4 mm diameter valve, sleeved gasket with a tinplate valve cup and a polyethylene dip tube. The actuator is a two piece high density polyethylene with 0.64 mm orifice and an output of 1.0 mL/sec

Modes for Carrying Out the Invention Example 1

A series of trials was conducted in a tropical environment in which a high concentration of mosquitoes were present. The trials involved individuals clothed in mosquito suits, each of which had a patch of fabric of predetermined area attached to their clothing. A predetermined amount of vapour active pyrethroid was sprayed onto each fabric patch. Landing inhibition of the mosquitoes was determined at various times.

The composition used to apply the vapour active pyrethroid comprised the specified concentration of vapour active pyrethroid dissolved in ethanol, the composition being contained in a pump spray package.

The results are set out in Table 1 below. It is evident that even after 8 hours, as little as 0.3 mg of metofluthrin was effective using 90% as a minimum efficacy level.

Example 2

A second trial was conducted in the Northern Territory of Australia at a temperature of 30°C +. In this trial, clothing combinations typically worn in these hot tropical areas were worn by individuals in the trial over mosquito suits. The vapour active pyrethroid, transfluthrin, was applied by spraying directly onto the clothing. The results for this trial are shown in Table. 2 below. Table 1

Key: Poly (polyester fabric) Trans (transfluthrin) Meto (metofluthrin) LI (landing inhibition) Table 2

Key: LI (landing inhibition) It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A method of repelling a pest species selected from the group consisting of mosquitoes, midges, flies, bees, wasps, ticks, mites, leeches, cockroaches and ants from a region around a clothed person, the method comprising applying sufficient of a composition, containing a vapour active pyrethroid in which the vapour active pyrethroid is dissolved in a carrier solvent and optionally water, to an area of the clothes of at least 100 cm and allowing the solvent to evaporate so that at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

2. A method as in claim 1 in which the region is a minimum of at least 10 cm from the individual.

3. A method as in claim 1 or claim 2 wherein the vapour active pyrethroid is selected from the group consisting of metofluthrin, transfluthrin, empenthrin, methothrin, tefluthrin, profluthrin and fenfluthrin or mixtures thereof.

4. A method as in claim 3 wherein the vapour active pyrethroid is metofluthrin or transfluthrin, preferably transfluthrin.

5. A method as in any one of claims 1 to 4 in which the amount of vapour active pyrethroid deposited is in an amount of from 0.2-200 mg.

6. A method as in any one of claims 1 to 5 in which the area of the clothes is from 200-15,000 cm²

7. A method as in any one of claims 1 to 6 in which the carrier solvent is selected from the group consisting of chlorinated hydrocarbons, alcohols, ketones,, alcohol and ketone mixtures, normal paraffins with a boiling point range of about 155-276°C, dearomatised aliphatic hydrocarbons and their blends in the boiling point range of about 33-265°C, isoparaffins in the boiling point range of about 150-300°C, glycol ethers in the boiling point range of about 120-243 °C; natural or synthetically derived aroma chemicals, preferably in the boiling point range of 120-250°C, and essential oils. 8. A method as in claim 7 wherein the carrier solvent is selected from the group consisting of 1,1,1-trichloroethane, dichloromethane, chloroform, methanol, ethanol, n- propanol, acetone/ethanol (1 : 1 by volume), pentane, heptane, hexane, monoterpenes and sesquiterpenes, including monoterpene and sesquiterpene alcohols, aldehydes, ketones, esters, oxides and hydrocarbons including linalool, geraniol, citronellal, citral, geranial, menthone, linalyl acetate, bornyl acetate, 1,

8-cineole and limonene.

9. A method as in claim 8 wherein the carrier solvent is ethanol.

10. A method as in any one of claims 1 to 9 including a co- solvent.

11. A method as in any one of claims 1 to 10 including water.

12. A method as in claim 11 wherein the composition is an emulsion.

13. Use of a composition, which comprises a vapour active pyrethroid dissolved in a carrier solvent, to repel a pest species selected from the group consisting of mosquitoes, midges, flies, bees, wasps ticks, mites, leeches, cockroaches and ants from a region around a clothed person in which sufficient of the composition is applied to an area of at least 100 cm of the clothes so that upon evaporation of the solvent, at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

14. A package for repelling a pest species selected from the group consisting of mosquitoes, midges, flies, bees, wasps, ticks, mites, leeches, cockroaches and ants from a region around a clothed person, the package comprising means to eject a composition contained therein as a spray adapted for application to an area of at least 100 cm of the clothes so that upon evaporation of a carrier solvent for a vapour active pyrethroid, both of which are included in the composition, at least 0.2 mg of the vapour active pyrethroid is deposited onto the area of the clothes.

15. A package for repelling a pest species as in claim 14 wherein the package is in the form of a pump spray.

16. A package for repelling a pest species as in claim 14 wherein the package is in the form of an aerosol.