WO2011120427A1

WO2011120427A1 - Insecticide composition and method of controlling insects using the same

Info

Publication number: WO2011120427A1
Application number: PCT/CN2011/072280
Authority: WO
Inventors: James Timothy Bristow
Original assignee: Rotam Agrochem International Co., Ltd
Priority date: 2010-04-01
Filing date: 2011-03-30
Publication date: 2011-10-06
Also published as: UA108229C2; TW201138621A; AR081105A1; MA34052B1; CO6602122A2; CN102651967A; CN102651967B; BR112012022607A2; ECSP12012143A; TWI434647B

Abstract

A pour-on formulation for control of an external parasite on an animal is provided, the formulation comprising an effective amount of an ectoparasiticidally active ingredient and at least one C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier. The ectoparasiticidally active ingredient is preferably an insect growth regulator (IGR). There is further provided the use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether for improving the properties of a pour-on formulation, in particular the properties of stability, efficacy and water-resistance.

Description

INSECTICIDE COMPOSITION AND METHOD OF CONTROLLING INSECTS

USING THE SAME

FIELD OF THE INVENTION

The present invention relates to a composition for controlling insects, in particular to a pour-on composition of an ectoparasiticidally active agent such as Insect Growth Regulator (IGR) and insecticides, and to a method of treating or controlling insects and parasites using the same, in particular the control of insects or parasites on animals. In particular, the present invention relates to a pour-on composition of water insoluble IGR in one or more non-aqueous solvents.

BACKGROUND OF THE INVENTION

The infestation of parasites, such as fleas, on domestic animals still represents for the veterinarian and for the keeper a problem that has not yet been satisfactorily resolved.

In the past, animals have generally been treated for the control of insects, and internal and external parasites by a range of different measures. It is also known to formulate compositions for treating infested animals as powders for application to the skin of the animal. The use of such dusting powders is generally not accepted without resistance by the animal, as it takes a few minutes to treat the whole skin surface evenly, and inevitably dust reaches the mouth, nose and eyes, causing discomfort or pain to the animal. Even during careful application, the possibility that the powder will be inhaled by the animal and the keeper cannot be excluded. In general, it is practically unavoidable that the person treating the animal will also come into significant contact with the composition and such contact can only be excluded or eliminated by time consuming and difficult measures.

It is also known to formulate agents for treating infested animals as liquid compositions. Such liquid compositions may be applied to the animal in a number of ways, for example by either dipping the whole animal in a bath containing the liquid composition comprising the parasiticidally effective agent or by spraying the entire body surface of the animal with such a composition. In certain cases, appropriate liquid compositions, such as flea-active shampoos, cannot be used successfully, as many animals, in particular cats and numerous dogs, do not let their keepers bathe them at all or only with force. In addition, the effect of such bathing treatment lasts for only a limited period of time, for example at most about one week, and the whole

troublesome procedure has to be repeated at frequent intervals. The same or similar problems arise when using dips or rinses.

With the use of sprays, for many persons there will be an unpleasant surprise, since most animals, especially cats, take flight or react aggressively as soon as they hear the spraying noise. Moreover, sprays also have all the disadvantages mentioned for solid compositions, in particular powders. In addition, the liquid compositions applied as sprays are generally more finely dispersed in the atmosphere than powders and therefore more easily inhaled by both the persons applying them and the animals being treated.

A number of parasites, for example fleas, are also controlled frequently with collars or bands impregnated with a suitable parasiticidally active agent, such as so-called flea collars, which guarantee good effectiveness for a transient period. A certain weakness of this means of treatment is, in particular, the locally very restricted application. The killing activity of the collar or band in the neck and chest areas is generally very high, perhaps even approaching 100 %. However, parts of the body further away are more difficult to treat and, in some cases, can be hardly affected. In addition, there is a time limit to the activity of these collars. Further, many of these collars are unattractive and may disturb the animal while being worn.

As a further alternative, one can also obtain discs, which hang from customary collars and contain an active component. These are typically of an attractive appearance, but their activity is generally unsatisfactory because the contact between the disc and the skin of the animal is insufficient.

More recently, it has been found that a number of parasiticidally effective substances may be applied by a localized application (so-called "pour-on" application). Although the parasitically effective substance is supplied by localized application, the active agent migrates so as to protect the whole external surface of the animal. By "localized application" it is meant that the active ingredient is only applied to a minor portion of the outer surface of the animal, generally as a line or a spot on the animal's back.

It has long been common practice to control external parasites on sheep, cats, dogs, cattle and other animals including goats, pigs and horses by the localized topical application of a pour-on formulation. In most pour-on formulations, and in all current water insoluble IGR pour-on formulations known to the inventors, the active agent is dissolved in a non-aqueous solvent system to produce a suitable pour-on formulation. The solvent present in such pour-on formulations is formulated to achieve good spread around the skin and/or penetration of the epidermis of the animals. To date, commercial pour-on formulations are suspensions, emulsifiable concentrates or solutions and are often comprised of at least one organic solvent. Solvents commonly used as carriers in such pour-on formulations include propylene glycol, paraffins, isoparaffins, aromatics, isopropyl myristate (IPM), glycol ethers, and alcohols such as n-propyl alcohol. US 4,672,072 discloses a preferred solvent system comprises 30-70% xylene, 20-40% cyclohexanone and 5-25% vegetable oil.

Unfortunately, the solvent systems utilized as carriers/vehicles in commercially available pour-on formulations may result in some form of tissue reaction when applied to the skin of the animal, which in turn leads to discomfort to the animal and in many cases, damage to the hide, sheepskin, or fleece and resultant economic loss. In particular, some animals have very sensitive skins which react to the solvent systems in some commercially available pour-on formulations. For example, aromatics such as xylene and the paraffins produce tissue reactions such as dryness, redness and cracking of the skin.

European patent No.0137627B1 discloses a pour-on formulation in which the active ingredient is an endoparasticide and the carrier comprises at least one saturated aliphatic ester of a mono alkyl ether of a mono- or poly-alkylene glycol such as 1 -ethoxyprop-2-yl acetate and 2-(n-butoxy)ethyl butyrate.

While the specification claims that such formulations are free from adverse skin reaction in treated sheep or cattle, it is noted that adverse epidermal reactions can still be observed in some animals, particularly in sheep with sensitive skin.

Additionally, with conventional pour-on formulations 95-98% of the applied active ingredient remains at the site of application bound to the animal's fleece or hair. This in turn results in a lack of efficacy. As a result, greater amounts of active ingredient must be applied to the animal, in order to effectively control the infestation.

Further, with many known formulations it has been found that when in contact with water, the active ingredient may precipitate out of the solvent formulation. Accordingly, solvent IGR pour-on formulations are less effective if applied to an animal which is wet, or if the animal is exposed to water, such as heavy rain, shortly after application and before the treatment has dried. When many pour-on formulations are brought into contact with water, the active ingredient rapidly precipitates out of the formulation. If this formulation is applied to a wet animal, or if the animal is exposed to rain before the treatment has dried on the animal, the active ingredient precipitates out of solution and is deposited along the back of the animal, the solvents also being washed away by the rain. This hinders or prevents the spread of the active ingredient around the entire animal. This phenomenon is particularly important in relation to those areas on the underside of the animal. This phenomenon reduces the effectiveness of solvent-only based formulations under these conditions.

Accordingly, there is an ongoing need to find safe carriers for use in pour-on formulations, which are not only non-irritant to the animal, but also allow the final product to be an efficacious, stable, water-fast formulation of low mammalian toxicity. It would be preferable that the carrier has the advantage of a satisfactory freezing point, suitable viscosity and is cost effective. In addition, it would be preferred that the carrier can be readily formulated with the active ingredient, for example can easily dissolve any active agent, are easy to use and provide superior operator safety. In the present invention it has been found that some or all of the above disadvantages with prior art pour-on formulations may be reduced or overcome by the use of an C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a solvent or carrier in a pour-on formulation. The final product based on the new carriers is an efficacious, stable, water-fast formulation of low mammalian toxicity, which is non-irritant to the animal.

SUMMARY OF THE INVENTION

The present invention relates to a use of one or more C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether as solvents or carriers in a pour-on formulation of a parasiticidally active agent. The formulation is effective in reducing the irritation to the animals. In addition, the use of the

aforementioned ethers as solvents or carriers provide a formulation that is efficacious, stable, water-fast and of low mammalian toxicity.

In a first aspect, the invention provides a non-irritant pour-on formulation adapted for localized application to an animal, which formulation comprises an effective amount of an ectoparasiticidally active ingredient, preferably an insect growth regulator (IGR), and at least one C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier.

The C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether have been found to be chemically and physically stable, non-flammable, of low

mammalian toxicity and non-irritant to the animal. It has been found that a pour-on formulation comprising one or more of the aforementioned ethers in combination with an ectoparasiticidally active component, in particular an IGR, is effective in treating a range of parasitic infestations on animals, such as ticks, fleas and the like.

The formulation of the present invention comprises a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether. Any suitable C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether or combination of two or more such ethers may be used. More preferably, the C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether is selected from diethylene glycol dimethyl ether, diethylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether, dibutylene glycol dimethyl ether, dibutylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl ether, dipropylene glycol diethyl ether, dipropylene glycol ethyl ether, dibutylene glycol diethyl ether, dibutylene glycol ethyl ether, diethylene glycol dipropyl ether, diethylene glycol propyl ether, dipropylene glycol dipropyl ether, dipropylene glycol propyl ether, dibutylene glycol dipropyl ether, dibutylene glycol propyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl ether, dipropylene glycol dibutyl ether, dipropylene glycol butyl ether, dibutylene glycol dibutyl ether, dibutylene glycol butyl ether and mixtures thereof.

The C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether may be present in the formulation with one or more other solvents, to form the carrier for the active ingredient. More preferably, the formulation comprises a carrier consisting of one or more C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether .

The formulation of the present invention comprises an ectoparasiticidally active ingredient effective in controlling ectoparasites infesting the target animal. Suitable ectoparasiticidally active agents include insecticides and acaricides. In one embodiment, the ectoparasiticidally active agent is preferably one that affects, controls or regulates the growth of the parasite, for example is a chitin synthesis inhibitor or is a hormone mimic, such agents being generally known as and referred to herein as an insect growth regulator (IGR). The formulation may contain a single parasiticidally active agent or a mixture of two or more such agents, for example a single IGR or a mixture of two or more IGRs. Any water insoluble ectoparasiticidally active agent may be used in the formulation according to the present invention.

Suitable ectoparasticidally active agents are known in the art and are commercially available. For example, suitable IGRs that are known in the art for inclusion in the formulation of the present invention include diflubenzuron, triflumuron, fluazuron, lufenuron, novaluron, hexaflumuron, teflubenuron, chlorfluazuron, flufenoxuron, noviflumuron, and methoprene. Such IGRs are commercially available.

The formulation of the present invention may contain one or more other components conventionally included in pour-on formulations, as known in the art. Examples of suitable additional ingredients are stabilizers, such as antioxidants, spreading agents, preservatives, adhesion promoters, active solubilisers, such as oleic acid, viscosity modifiers, UV blockers or absorbers, and colorants. Surface active agents, including anionic, cationic, non-ionic and ampholytic surface active agents, can also be included in the pour-on formulations.

As noted above, the formulation of the present invention is of use in the control of infestations in animals. Accordingly, in a second aspect, the present invention provides a method of controlling insects or parasites on an animal, which method comprises externally applying an ectoparasiticidally effective amount (e.g. volume) of a pour-on formulation according to the first aspect of the invention. The formulation may be applied to some or all of the exterior of the animal. The method preferably comprises applying the formulation to a localized area of the external surface of the animal. In this respect, the term 'localized area' is a reference to an area of the exterior of the animal that is a small fraction of the total surface area of the animal. In particular, the localized area is from 0.1 to 10% of the surface area of the animal, more particularly from 0.5 to 5% of the external surface of the animal. It is a particular advantage of the formulation of the present invention that it need only be applied to a very small region of the surface of the animal, while still providing effective treatment against the infestation.

The formulation may be applied to a single localized area of the animal. Alternatively, the animal may be treated by applying the formulation to a plurality of different localized areas, the areas being sufficiently spaced apart.

The method may comprise applying the formulation to any suitable region of the animal. Preferred regions are the neck and back of the animal.

Another aspect of this invention relates to the use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier in a non-irritant pour-on formulation for controlling an external parasite in an animal, wherein the formulation also comprises an effective amount of an ectoparasiticidal agent.

DETAILED DESCRIPTION OF THE INVENTION

As noted above, in the present invention it has been surprisingly found that C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether are not only non-toxic and non-irritant carriers that can be used to prepare improved pour-on ectoparasiticidal formulations, but also can improve the pour-on formulations to be more efficacious, stable and water-fast.

For example, it has been found that IGR formulations prepared according to the present invention kill the majority of ticks (>96%) within 4-5 hours of application to a localized area of the animal.

Further, it has been found that the formulations of this invention are able to tolerate up to 10% by volume of water before the water insoluble IGR begins to slowly precipitate from the carrier solvents. This compatibility with water means that if the formulation is added to a wet animal, the active ingredient will continue to spread on the skin of the animal, but not run off the animal. This increased tolerance to water helps to increase the efficacy of the formulation. Similarly, if it rains shortly after the formulations of this invention are applied, the rain fall will help to spread the formulation across the skin of the animal without washing it off. This will again help to increase the efficacy of the formulation.

Additionally, the formulations also are efficacious when applied to the animal and no rain occurs for several weeks. In all these instances, it is believed that the carriers aid the spread of active ingredient over the surface of the animal. These beneficial effects are not obtainable at the moment with traditional or known solvent-based formulations.

In addition, this invention provides non-toxic and non-irritant carriers that can be used to prepare improved pour-on formulations. The invention also provides these improved formulations, which are especially beneficial because they can be topically applied to animals of agricultural worth to control ectoparasites without causing adverse epidermal reaction in the animals.

The invention also provides as noted above, a method of controlling ectoparasites in an animal of agricultural worth by topically applying one of the non-irritant, pour-on ectoparasiticidal formulations on the animal.

The formulation may contain one or more ectoparasiticidally active ingredients, including acaricides and insecticides. Such active ingredients are known in the art and include those active ingredients typically administered by pour-on formulations. The active ingredient is preferably an insect growth regulator (IGR). The active ingredient may be present in the formulation in any suitable amount. In particular, the active ingredient may be present in an amount of from 0.05 to 60% by weight of the composition, more preferably from 0.1 to 50% by weight, still more preferably from 0.1 to 40% by weight.

The ectoparasiticidally active ingredient may be any water insoluble agent. In particular, any water insoluble IGR can be used in the formulation. Suitable IGRs are known in the art and include diflubenzuron, triflumuron, fluazuron, lufenuron, novaluron, hexaflumuron, teflubenuron, chlorfluazuron, flufenoxuron, noviflumuron, and methoprene. Such IGRs are commercially available.

In the pour-on formulations of this invention, the active agent can be a single ectoparasiticidal compound or a combination of two or more

ectoparasiticidal compounds.

The formulation of the present invention contains a carrier comprising a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether. The composition may comprise a single C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether or a combination of two or more C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether.

More particularly, the carrier of the formulation comprises an ether selected the group ofC2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether , which includes diethylene glycol dimethyl ether, diethylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether, dibutylene glycol dimethyl ether, dibutylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl ether, dipropylene glycol diethyl ether,

dipropylene glycol ethyl ether, dibutylene glycol diethyl ether, dibutylene glycol ethyl ether, diethylene glycol dipropyl ether, diethylene glycol propyl ether, dipropylene glycol dipropyl ether, dipropylene glycol propyl ether, dibutylene glycol dipropyl ether, dibutylene glycol propyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl ether, dipropylene glycol dibutyl ether,

dipropylene glycol butyl ether, dibutylene glycol dibutyl ether, dibutylene glycol butyl ether and mixtures thereof.

The formulation may contain one or more C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether in an amount of from 40 to 99.95% by weight of the composition, more preferably from 50 to 99.9% by weight, still more preferably from 60 to 99% by weight.

In one embodiment of the first aspect of the invention, a pour-on formulation for control of an external parasite in an animal of agriculture worth, is a formulation that comprises from 0.1 to 40% by weight of at least one active agent selected from the insect growth regulators and from 40 to 99.9% by weight of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether.

The pour-on formulation of this invention may be provided in any suitable form. In particular, the formulation may be in the form of a liquid, powder, emulsion, foam, paste, aerosol, ointment, salve or gel. Typically, the pour-on formulation is a liquid. The carriers of the formulation of this invention are non-aqueous. The active agent may be combined with a carrier in any suitable manner. For example, the active ingredient may be suspended, dissolved or dispersed in the carrier. As noted above, the carrier in the formulation of the present invention promotes the penetration of the active agent through the animal's coat and the spread of the active agent over the skin of the animal.

In addition to the carrier and the active agent, the pour-on formulations of this invention may also comprises one or more additional ingredients.

Examples of suitable additional ingredients are stabilizers, such as

antioxidants, spreading agents, preservatives, adhesion promoters, active solubilisers, such as oleic acid, viscosity modifiers, UV blockers or absorbers, and colorants. Surface active agents, including anionic, cationic, non-ionic and ampholytic surface active agents, can also be included in these formulations.

The formulations of this invention typically comprises an antioxidant. Suitable antioxidants are known in the art and are commercially available. One of suitable antioxidants is BHT (butylated hydroxytoluene). The antioxidant is generally present in amounts of from 0.05 to 10% by weight of the composition, more preferably from 0.1 to 5% by weight.

Suitable spreading agents for inclusion in the formulation are known in the art and are commercially available. Suitable spreading agents for use in the pour-on formulations include isopropyl myristate(IPM), IPP(isopropyl palmitate), caprylic/capric acid esters of saturated Ci₂ - Ci₈ fatty alcohols, oleic acid, oleyl ester methyl oleate, triglycerides, silicone oils. The spreading agents may be present in an amount of from 0.05 to 10% by weight of the composition, more preferably from 0.1 to 5% by weight.

The pour-on formulations of this invention may be prepared according to known techniques. For example, where the formulation is a solution of the active ingredient in the carrier, the active agent is mixed with the carrier, using heat and stirring where required. Auxiliary or additional ingredients may be added to the mixture of active agent and carrier or they can be mixed with the active agent prior to the addition of the carrier. If the pour-on formulation is an emulsion or suspension, these formulations are similarly prepared using known techniques.

A general procedure for preparing the formulations involves these steps: 1) weighing out the desired amount of technical active agent; 2) adding the appropriate antioxidant (if present); 3) adding the solubilizer (if present), and dissolving by stirring; 4) making up the desired volume by adding the carrier; 5) mixing by stirring and gently heating, if necessary, for example to up to 50°C; 6) dispensing into impervious containers and protecting from light.

This invention further provides a method of controlling an external parasite in an animal of agriculture worth, said method including applying topically to the animal an ectoparasiticidally effective volume of a pour-on formulation according to the invention, in particular to a localized area of the external surface of the animal.

The formulation of the present invention may be used to control or treat a wide range of ectoparasites, with the active ingredient being selected for its activity with respect to the target parasite. Target external parasites include lice, ticks, mites, biting flies, carnivorous flies and fleas. The formulations may be used on a wide range of animals, in particular animals having agricultural worth. Animals of agricultural worth include cattle, sheep, goats, pigs, horses, cats, dogs.

The pour-on formulation of the present invention may be applied in any suitable manner. Suitable techniques for application are known in the art. For example, the formulation is typically applied by pouring in one or several lines or in a spot on the dorsal midline (back) or shoulder of an animal. More preferably, the formulation is applied by pouring it along the back of the animal, following the spine. The formulation can also be applied to the animal by other conventional methods, including wiping an impregnated material over at least a small area of the animal, or applying it using a commercially available applicator, such as by means of a syringe, by spraying or by using a spray race.

An effective amount of the pour-on formulation for topical application will depend on several factors, for example the animal being treated, the active agent in the formulation, and the specific formulation being used. Generally, the formulation is applied in an amount to provide from about 0.1 to 2000mg of the active agent/kg of animal body weight.

As noted above, it has been found that the use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier in a pour-on formulation, in particular a formulation comprising an active ingredient for treating or controlling ectoparasites on an animal, can be improved. In particular, the use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier has been found to improve the properties of efficacy, stability and water-resistance of the formulation. In addition, it has been found that the C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether cause reduced irritation to the animal.

Accordingly, in a further aspect, the present invention provides the use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier in pour-on formulation for reducing irritation to the animals.

In a further aspect, the present invention provides the use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier in a pour-on formulation for improving the efficacy, stability, and water-resistant properties of the formulation.

The present invention also provides a method of improving the efficacy, stability and/or water-resistant properties of a pour-on formulation and/or reducing the irritation to the animal to which the formulation is topically applied, the method comprising including in the formulation a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier.

In a still further aspect, the present invention provides a method of controlling an external parasite on an animal, the method comprising topically applying a formulation as hereinbefore described.

The present invention also provides the use of a formulation as

hereinbefore described in the control of external parasites on an animal.

The following examples further illustrate details for the preparation and use of the compositions of this invention. The invention, which is set forth in the foregoing disclosure, is not to be limited either in spirit or scope by these examples. Those skilled in the art will readily understand that known variations of the conditions and processes of the following preparative procedures can be used to prepare these compositions.

EXAMPLES

A general procedure for preparing the formulations involves these steps:

1) weighing out the desired amount of technical active agent;

2) adding the appropriate antioxidant (if present); 3) adding the solubilizer (if present), and dissolving by stirring;

4) making up the desired volume by adding the carrier;

5) mixing by stirring and gently heating, if necessary, for example to up to 50^°C;

6) dispensing into impervious containers and protecting from light.

The above general procedure was followed in the preparation of the pour-on formulations of Examples 1 to 12.

Example 1

A pour-on formulation was prepared having the following composition:

Lufenuron tech 1.0g

Diethyl glycol dimethyl ether 98.9g

BHT 0.1g

Total 100g

Example 2

A pour-on formulation was prepared having the following composition: 2.5g

77.5g

20g

100g

Example 3

A pour-on formulation was prepared having the following composition:

Hexaflumuron tech 5.0g

Dipropylene glycol dibutyl ether 84.9g

TWEEN 80 10g

BHT 0.1g

Total 100g

Example 4

A pour-on formulation was prepared having the following composition:

Triflumuron tech 5.0g Dipropylene glycol dimethyl ether 80g

ATLAS G-1674 BAA 10g

Agnique BL3080 5.0g

Total 100g

Example 5

A pour-on formulation was prepared having the following composition:

Lufenuron 1.0g

Dipropylene glycol methyl ether 98.9g

BHT 0.1g

Total 100g

Example 6

A pour-on formulation was prepared having the following composition:

Diflubenzuron tech 25g

TWEEN80 10g Dipropylene glycol methyl ether 55g

Gamma-butylactone 10g

Total 100g

Example 7

A pour-on formulation was prepared having the following composition:

Flufenoxuron tech 40g

TWEEN80 10g

Diethylene glycol ethyl ether 50g

Total 100g

Example 8

A pour-on formulation was prepared having the following composition:

Noviflumuron tech 15g

TWEEN80 12g

Dipropylene glycol diethyl ether 68g

Benzyl alcohol 5.0g Total 100g

Example 9

A pour-on formulation was prepared having the following composition:

Teflubenuron tech 16g

ATLAS G- 1674 BAA 10g

Agnique BL3080 10g

Dipropylene glycol ethyl ether 63g

BHT 1.0g

Total 100g

Example 10

A pour-on formulation was prepared having the following composition:

Chlorfluazuron tech 40g

ATLAS G- 1674 BAA 10g

Agnique BL3080 5.0g

Dibutylene glycol diethyl ether 40g Benzyl alcohol 5.0g

Total 100g

Example 11

A pour-on formulation was prepared having the following composition:

Methoprene tech 10g

TWEEN80 10g

Dibutylene glycol ethyl ether 74.9g

Gamma-butylactone 5.0g

BHT 0.1g

Total 100g

Example 12

A pour-on formulation was prepared having the following composition:

Diflubenuron tech 5.0g

Chlorfluazuron tech 5.0g

TWEEN80 10g Dipropylene glycol dipropyl ether 40g

Dibutylene glycol dipropyl ether 39,9g

BHT 0.1g

Total 100g

Results of Trials

Trials were conducted to assess the comparative efficiency and any undesirable effects of certain pour-on formulations of this invention in comparison with commercially available pour-on formulation in the control of external parasites, like ticks and fleas in cattle.

Tests were carried out using the following compositions compared to untreated controls and a commercially available pour-on formulation:

Composition (1): A formulation prepared according to Example 1 ;

Composition (2): A formulation prepared according to Example 5;

Composition (3): 2% Diflubenzuron pour-on commercial product based on N-methyl-2-pyrrolidone as the carrier (Stampede coopers, Farm Service NSW).

Compositions (1) to (3) were tested as follows:

The test subjects were adult cattle at Isaiah Pole Ntauiti's farm in llmugush, in the Mashuru division of Kajiado district, which is 76 km from Nairobi. This particular area is at 3000ft and has less than 500mm of rain fall per year. The region is important for livestock herders, mainly the Masai people, who are cattle herders. The area has a significant population of wildlife, including wildebeest, zebra and antelopes, which graze side by side with the cattle, as farms are not fenced and the area borders a game reserve. Due to this, the tick challenge within the region is extremely high and is a suitable area for testing acaricides.

The animals were tested in groups, as summarized in Table 1.

Table 1

Experimental groups and treatment

The adult cattle were randomly divided into four groups each having five animals selected on basis of even weight spread from the herd average of 350kg, tagged and treated and allowed to graze normally and freely. The selected groups were each treated with an assigned formulation (composition 1 , composition 2, and composition 3) as in Table 1.

Each animal received 40ml (or as recommended by manufacturer) of pour-on formulation applied uniformly along the spine from the base of the horns to the end of the tail (beginning of whisks) using a suitable applicator.

Treatment was repeated once weekly for 4 weeks on all animals. All treatments were given 7 days apart with the first day of treatment being day 0, subsequent treatments being on days 7, 14, 21 and 28. Each animal was treated with 40ml of the respective pour-on formulation at each treatment.

The cattle were suitably restrained to allow for absolute tick counts and application of the pour-on formulations. Tick counts for all animals were recorded on days 1 ,3,5,7 of every week.

The efficacy of each formulation was calculated using a modified formula according to Abbott:

% Efficacy = 100 - Tick count for Treatment x 100

Tick count for Control

Efficacy of the compositions of this invention was assessed by comparing post treatment tick counts on the treated cattle, with counts on a group of untreated cattle.

The composite weekly tick count totals and consolidated total counts for the 28-day period are presented in the Table 2. WEEK TOTAL

EFFICACY

GROUP DAY 1 2 3 4 TOTAL

%

0 653 653

Y 1 0 0 0 0 0 100

3 0 0 0 0 0 100

5 0 0 0 0 0 100

7 0 0 0 0 0 100

0 179 0 0 0 179

B 1 0 0 0 0 0 100

3 0 0 0 0 0 100

5 0 0 0 0 0 100

7 0 0 0 0 0 100

0 149 149

G 1 148 146 147 145 586

3 150 152 152 154 608

5 153 155 156 156 620 7 147 146 145 147 585

0 653 653

R 1 0 0 700 0 700

3 0 0 710 0 710

5 0 0 730 0 730

7 0 0 0 0 0 100

Table 2

RESULTS AND OBSERVATIONS

1. The initial spread of Composition 1 and Composition 2 was similar. Both compositions spread well over the skin of the animal. However, Composition 3 spread more slowly. All three compositions spread within 4 to 5 hours of application on the animal, in particular down to the midline of the animal from the spine line. The ticks, tsetse flies and fleas on the mid line were killed off.

2. Composition 3 caused excessive matting of hairs at the site of application and increased irritation on exposure to sunlight with cattle seeking shade to avoid the pain. Compositions 1 and 2 caused little to no matting of the hair and no irritation to the skin of the animals. There was rain fall as from day 15 of the trial. The rain fall did not affect the efficacy of Composition 1 and Composition 2. In contrast, Composition 3 was not water-fast and the rain caused tick and flea populations to increase before the following treatment. Composition 1 and Composition 2 effectively controlled ticks during the period of trial. Composition 1 and composition 2 repelled Tsetse flies and had a knock down effect on the flies. Based on these observations, the compositions according to this invention (Compositions 1 and 2) spread well down to the midline of the animal, causing no skin irritation, in particular killed ticks and repelled flies for up to 7 days. The products of this invention can be used once every two weeks. The compositions of the present invention were not reduced in there effectiveness by the presence of water, in particular during and after rain fall.

Claims

1. A pour-on formulation for control of an external parasite on an animal comprising an effective amount of an ectoparasiticidally active ingredient and at least one C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier.

2. The formulation according to claim 1 , wherein the ectoparasiticidally active ingredient comprises an insect growth regulator (IGR).

3. The formulation according to claim 2, wherein the insect growth regulator (IGR) comprises a compound selected from diflubenzuron, triflumuron, fluazuron, lufenuron, novaluron, hexaflumuron, teflubenuron,

chlorfluazuron, flufenoxuron, noviflumuron, and methoprene, and mixtures thereof.

4. The formulation according to any preceding claim, comprising from 0.1 % to 40% by weight of the ectoparasiticidally active ingredient and from 40% to 99.9% by weight of at least one C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether.

5. The formulation according to any preceding claim, wherein two or more ectoparasiticidally active ingredients are present.

6. The formulation according to any preceding claim, wherein two or more C2-C4 dialkylene glycol di-/mono- C1-C4 alkyl ether are present.

7. The formulation according to any preceding claim, wherein the C2-C4

dialkylene glycol mono/di - C1-C4 alkyl ether is diethylene glycol dimethyl ether, diethylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether, dibutylene glycol dimethyl ether, dibutylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl ether, dipropylene glycol diethyl ether, dipropylene glycol ethyl ether, dibutylene glycol diethyl ether, dibutylene glycol ethyl ether, diethylene glycol dipropyl ether, diethylene glycol propyl ether, dipropylene glycol dipropyl ether, dipropylene glycol propyl ether, dibutylene glycol dipropyl ether, dibutylene glycol propyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl ether, dipropylene glycol dibutyl ether, dipropylene glycol butyl ether, dibutylene glycol dibutyl ether, dibutylene glycol butyl ether or a mixture thereof.

8. The use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a

carrier in pour-on formulation for reducing the irritation to the animals.

9. The use of a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a

carrier in a pour-on formulation for improving the efficacious, stability, and water-resistant properties of the formulation.

10. A method for improving the efficacy, stability and/or water-resistant

properties of a pour-on formulation and/or reducing the irritation to the animal to which the formulation is topically applied, the method comprising including in the formulation a C2-C4 dialkylene glycol mono/di - C1-C4 alkyl ether as a carrier.

11. A method of controlling an external parasite on an animal, the method

comprising topically applying a formulation according to any of claims 1 to 7.

12. The use of a formulation according to any of claims 1 to 7 in the control of external parasites on an animal.