TWI800570B - Mosquito repellent composition - Google Patents

Abstract

The current invention relates to an insect repellent composition comprising: a vapour-active pyrethroid; a flammable bulk material; and a binder; wherein the vapour-active pyrethroid is selected from one or more of the group selected from metofluthrin, transfluthrin, dimefluthrin, meperfluthrin, renofluthrin and heptafluthrin. The invention also includes a method of preparing an insect repellent composition, an article comprising the composition, a kit comprising such an article and a method of repelling insects by igniting the composition.

Description

Mosquito repellent composition

Field of Invention This invention relates to a composition and method for repelling insects, particularly flying insects such as mosquitoes.

Background of the Invention The list or discussion of previously published documents in this specification should not be regarded as an admission that the documents are part of the prior art or common knowledge.

In many parts of the world, the buzzing of mosquitoes can be more than just a distraction. It signals the potential for a bite to transmit diseases such as malaria, dengue fever, chikungunya, and Zika. Thus, even when an individual tries to protect themselves from insect repellent, the repellent may not be effective until the mosquito is inches away. The constant buzzing of a mosquito can be annoying and can even induce anxiety or fear of being bitten.

Other pests can also pose a threat to individuals through bites or stings, which can cause irritation, and in severe cases, lead to life-threatening allergies. These species include, but are not limited to, midges, sand flies, black flies, houseflies, jungle flies, horseflies, bees, wasps, ants, cockroaches, leeches, ticks, and mites. While most (but not all) of these species are not disease vectors, their presence in or around humans and animals can cause suffering for various reasons.

In light of the above, considerable efforts have been made to keep these pests away from humans and/or animals, with varying degrees of success. These efforts generally focus on physical barriers, pesticide formulations, and insecticide formulations.

Physical barriers, such as mosquito nets soaked in pesticides and/or insect repellents, have proven effective in preventing bites, but require a person to remain in one place, such as when sleeping in bed. However, this barrier is not suitable for mobile people (because it restricts movement) or recreational environments, whether indoors or outdoors, as it may prevent individuals from enjoying their surroundings.

Pesticides have limited success in reducing or eliminating the threat of bites to individuals in enclosed environments (e.g., indoors). Pesticides are provided in the form of aerosol sprays, combustible mosquito coils, and electronic devices that release pesticides over a period of time. All of these forms rely on releasing an effective amount of pesticide into the air to eliminate pest species within a defined space for the duration of the pesticide's effectiveness.

The active ingredients (especially insecticides/pesticides) used in conventional mosquito coils are slowly released into the environment as the coil burns. Therefore, mosquito coils (and similar products) require initialization time before they can provide a sufficient pesticide concentration in the enclosed space to achieve an acceptable level of protection. In other words, using mosquito coils does not provide immediate protection against mosquitoes, leading to a period where the user believes they are protected but are not, increasing the risk of mosquito bites. In areas where mosquitoes have developed resistance to some insecticides, a larger amount of insecticide needs to enter the environment before the mosquitoes are knocked down, thus increasing the initialization time and the risk of mosquito bites. To provide protection, conventional mosquito coils must burn for a long time. This means that there is a risk of fire if used indoors, such as to protect a sleeping user, or at least the possibility that the smoke produced by the burning mosquito coil may make the user uncomfortable.

JP2011012056 discloses a method for controlling pests in which burning mosquito coils releases pyrethroid compounds with a vapor pressure of 2× ^10⁻⁴ to 1× ^10⁻² mmHg at 30°C. The specification states that pyrethroids have particle sizes smaller than 1µm, so they are carried into the smoke generated by burning mosquito coils as small particles and volatilize upon heating. Compared to conventional mosquito coils, these coils contain a larger amount of insecticidal components, significantly reducing the rate of volatilization of the insecticidal components caused by the burning of the mosquito coil and the removal of insecticidal particles by the smoke generated during combustion.

Therefore, there is a need for a mosquito coil alternative that can quickly release the active ingredient while providing long-lasting protection without excessive pesticide load or requiring prolonged smoke production to carry pesticide particles into the air.

Summary of the Invention In a first embodiment, an insecticide composition is provided, comprising: a vapor-activated pyrethrin; a flammable bulk material; and a binder; wherein the vapor-activated pyrethrin is selected from one or more of the group consisting of meperfluthrin, renofluthrin, and heptafluthrin, and more particularly metofluthrin, transfluthrin, and dimefluthrin, and the vapor-activated pyrethrin is capable of... The pyrethroid is present in amounts providing the following release rates: wherein the pyrethroid is metronidazole, with a release rate from 0.05 to 0.30 mg/min; wherein the pyrethroid is phenylephrine, with a release rate from 0.15 to 0.45 mg/min; wherein the pyrethroid is tetrafluoroethylene, with a release rate from 0.05 to 0.50 mg/min; wherein the pyrethroid is cyfluthrin, with a release rate from 0.04 to 0.40 mg/min; wherein the pyrethroid is renafenone, with a release rate from 0.05 to 0.50 mg/min; and wherein the pyrethroid is heptafluoroethylene, with a release rate from 0.05 to 0.50 mg/min.

In a second embodiment, a method for preparing an insecticide composition according to the present invention is provided, comprising the following steps: a) providing a vapor-activated pyrethroid; b) providing a flammable bulk material; c) providing a binder; and d) mixing the vapor-activated pyrethroid, the flammable bulk material, and the binder with water.

In the third embodiment, an object comprising an insect repellent composition according to the invention is provided.

In the fourth embodiment, a kit is provided comprising an object according to the invention and a base supporting the object.

In the fifth embodiment, a method for repelling insects is provided, wherein the method involves burning an insect repellent composition according to the invention to repel insects.

Detailed Description of Preferred Embodiments This invention relates to an insecticide composition comprising a vapor-activated pyrethroid. It further relates to an object comprising the insecticide composition and a method for preparing the composition and the object obtained therefrom. This invention further relates to a sleeve comprising the object and a base supporting the object. It further relates to a method of insect repelling, wherein the method involves burning the insecticide composition to repel insects. The composition of this invention comprises a combustible bulk material and a binder, and optionally contains a preservative and an adjuvant or other additive. The vapor-activated pyrethroid is selected from one or more of the group consisting of chlorpyrifos, renafenone, sevomethrin, and more particularly mefenoxam, phenylephrine, and tetrafluoromethrin, and is present in an amount capable of providing the following release rates: wherein the pyrethroid is mefenoxam, the release rate is from 0.05 to 0.30 mg/min; wherein the pyrethroid is phenylephrine, the release rate is from 0.15 to 0.45 mg/min. The proposed pyrethroid is tetrafluoromethrin, with a release rate from 0.05 to 0.50 mg/min; The proposed pyrethroid is cyfluthrin, with a release rate from 0.04 to 0.40 mg/min; The proposed pyrethroid is renafurine, with a release rate from 0.05 to 0.50 mg/min; and The proposed pyrethroid is heptafluoromethrin, with a release rate from 0.05 to 0.50 mg/min.

As used in this article, the term "repel (repelling or repellent)" or its equivalents generally refer to preventing insects from entering or remaining in a place, or, if they do enter a place, preventing them from landing on people and/or animals. This includes exposure to behavioral effects such as confusion and disorientation leading to uncoordinated landings on human and/or animal targets, as well as being knocked down or killed.

When used herein, the term "release rate" is the amount of pyrethroid present in the composition multiplied by its evaporation rate, divided by the burning time of the bulk material. Those skilled in the art will understand that the release rate of different pyrethroids may vary, but as long as the release rate is sufficient to release a adequate amount of pyrethroid into the environment, the same insect-killing effect will be achieved. This invention achieves effective kill without using excessive amounts of pyrethroid in the composition. The inventors recognize that relatively low concentrations of pyrethroid in combustible bulk materials may be effective in certain situations (e.g., indoors or enclosed spaces).

When used herein, the term "evaporation rate" refers to the proportion of pyrethroids present in the composition that are released into the air as vapors during the combustion of the composition. It will be less than 100% because, for example, some pyrethroids may decompose during the combustion of the composition.

When used herein, the term “burning time” means the time during which an object made from the components disclosed herein burns before it is exhausted or reaches a point where it can no longer support combustion.

In one embodiment, the pyrethroid may be metronidazole and the release rate may be from 0.05 to 0.30 mg/min.

In one embodiment, the pyrethroid may be tetrafluoromethrin and the release rate may be from 0.05 to 0.50 mg/min.

In one embodiment, the pyrethroid may be Adfurine and the release rate may be from 0.15 to 0.45 mg/min.

In one embodiment, the pyrethroid may be chlorpyrifos and the release rate may be from 0.04 to 0.40 mg/min.

In one embodiment, the pyrethroid may be renafurine and the release rate may be from 0.05 to 0.50 mg/min.

In one embodiment, the pyrethroid may be heptafluthrin and the release rate may be from 0.05 to 0.50 mg/min.

In one embodiment, the composition disclosed herein may provide an amount of metronidazole capable of releasing at a rate of 0.08 to 0.27 mg/min. In one embodiment, hydantoin may be provided capable of releasing at a rate of 0.16 to 0.45 mg/min. In one embodiment, tetrafluoromethrin may be provided capable of releasing at a rate of 0.06 to 0.21 mg/min.

Those skilled in the art will be able to determine the appropriate amount of pyrethroid contained in the composition within the above-set release rate range. In one embodiment, the amount of metronidazole present can be from 0.10 to 5.00% w/w, preferably from 0.50 to 3.00% w/w, and more preferably from 0.35 to 0.66% w/w. In one embodiment, the amount of hymexazol present can be from 0.1 to 5.00% w/w, preferably from 1.00 to 3.00% w/w, and more preferably from 0.56 to 1.00% w/w. In one embodiment, the amount of tetrafluoromethrin present can range from 0 to 5.00% w/w, more preferably from 1.00 to 3.00% w/w, and even more preferably from 0.24 to 1.10% w/w.

The pyrethroid may be provided in any physical form. In one embodiment, the pyrethroid may be provided as the compound itself. The compound may be in solid, semi-solid, or liquid form.

Typically, when the compound is provided in its entirety, it may be designated as a "technology class". In an alternative embodiment, the pyrethroid may be provided in emulsion form. In yet another embodiment, the pyrethroid may be provided in microemulsion form.

Any suitable combustible bulk material may be used. In one embodiment, the combustible bulk material may be in powder form of a substance selected from one or more of the group consisting of wood, sawdust, paper, cardboard, coconut shell, powder made from nut shells other than leaves or coconut shells, jute, bagasse, rice husk, tea residue, coffee grounds, charcoal, and pyrethrum residue.

In one embodiment, the combustible bulk material may be one or more substances selected from the group consisting of wood flour, coconut shell powder, charcoal powder and pyrethrum residue.

Those skilled in the art will be able to determine the appropriate amount of the flammable bulk material contained in the composition. The amount of the flammable bulk material will be affected by the flammability of the selected material, the desired burning time, and the properties of the other components in the composition. In one embodiment, the flammable bulk material may be provided in an amount of 60 to 95% w/w, preferably 70 to 90% w/w, and more preferably 75 to 85% w/w.

Any suitable binder may be used. In one embodiment, the binder may be selected from one or more of the following materials: joss powder, α-starch, makko powder, tabu powder, carboxymethyl cellulose, guar gum, cassava starch, tamarind starch, and tamarind kernel powder.

In one embodiment, the binder may be selected from one or more of the following materials: perfume powder, α-starch, Makko powder, sage powder, carboxymethyl cellulose and guar gum.

In one embodiment, the binder may be a fragrance and/or α-starch. In one embodiment, the ratio of fragrance to α-starch is from 4:1 to 6:1.

Those skilled in the art will be able to determine the appropriate amount of the binder contained in the composition. The amount of the binder will be affected by the binding strength of the binder and the properties of the other components in the composition. In one embodiment, the binder may be provided in an amount of 5 to 40% w/w, preferably 10 to 30% w/w, and more preferably 15 to 20% w/w.

In one embodiment, the insecticide composition may further include a preservative. For example, the preservative may be selected from one or more materials chosen from sodium acetate dehydrate, potassium sorbate, and sodium benzoate (e.g., sodium acetate dehydrate and sodium benzoate, such as sodium acetate dehydrate).

Those skilled in the art will be able to determine the appropriate amount of the preservative contained in the composition. The function of the preservative is to prevent the growth of mold and microorganisms that may affect the performance and appearance of the object containing the composition. The amount of the preservative will be affected by the desired shelf life and the properties of the other components in the composition. The preservative may be provided in amounts of 0 to 5% w/w, preferably 0.05 to 3% w/w, and more preferably 0.1 to 1% w/w.

In one embodiment, the insect repellent composition further includes other additives or excipients. These other additives include, but are not limited to, emulsifiers, fuel accelerators or oxygen-providing agents, flame retardants, preservatives, colorants, and fragrances. These may be incorporated into the composition and, in some cases, applied as a topcoat to objects formed from the composition.

A colorant enables an object containing the component to be colored for aesthetic reasons. In one embodiment, the amount of the colorant present can be from 0 to 5% w/w, more preferably from 0.1 to 0.5% w/w. Suitable colorants include, but are not limited to, malachite green, acid red, and rhodamine B. The presence of a fragrance in an object provides a consumer-friendly aroma when the object is burned. In one embodiment, the amount of the fragrance present in the object can be from 0 to 1% w/w, more specifically from 0.1 to 0.5% w/w. Suitable fragrances include, but are not limited to, jasmine or other flower oils or synthetic forms thereof. Fragrance powder can also act as a fragrance. The fragrance is typically introduced onto the surface of the object after it has been formed by impregnation.

The composition may contain an emulsifier. The emulsifier may be conjugated with the pyrethroid before being added to the composition, or the emulsifier and the pyrethroid may be added separately. In a particularly advantageous embodiment, the emulsifier may be introduced into the composition using an emulsion (EC) containing a pyrethroid solution formulated in an organic solvent and at least one emulsifier. Typically, the amount of the emulsifier present in the EC can be from 5% to 25% w/w, preferably from 10% to 20% w/w. A range of emulsifiers can be used, including, but not limited to, any one or a combination of anionic, cationic, amphoteric, nonionic, and polymeric surfactants. Solvents commonly used in EC formulations include hydrocarbon fluids, such as dearomatic hydrocarbon fluids, isoalkyl hydrocarbon fluids, and aromatic fluids.

If an oxygen-providing agent or accelerator is present, its function is to increase the rate of combustion of the substance. The amount of such oxygen-providing agent or accelerator may range from 0 to 5% w/w. Suitable accelerators or oxygen-providing agents for fuels include, but are not limited to, potassium nitrate and lead acetate. If a flame retardant is present, its function is to decrease the rate of combustion of the substance. The amount of such flame retardant may range from 0 to 5% w/w. Suitable flame retardants include, but are not limited to, potassium carbonate, boric acid, and talc.

In one embodiment, the composition may be made from: a vapor-activated pyrethroid selected from mefenoxuron and tetrafluoroethylene, alone or in combination, wherein the amount of the pyrethroid present may be from 0.2% to 1.0% w/w; covering both mefenoxuron and tetrafluoroethylene; a combustible bulk material, which may be one or more of a mixture of wood flour, coconut shell powder, charcoal powder and pyrethroid. The residue comprises a group, and is present in amounts ranging from 70% to 90% w/w; a binder, which may be flavoring powder and α-starch, with a flavoring powder:α-starch w/w ratio of 4:1 to 6:1; a preservative, which may be dehydrated sodium acetate, and is present in amounts ranging from 0.1% to 0.5% w/w; and an adjuvant and/or additive, and is present in amounts ranging from 0.5% to 5% w/w.

In one embodiment, a 1.3 to 1.5 g formulation containing at least 0.25% w/w of metronidazole and/or tetramethrin is provided. When tested with Culex quinquefasciatus in a free-flight test immediately after substantial pyrolysis of the formulation, this formulation provides KT ₅₀ from 7.0 to 10 minutes in a 30 ^m³ space. After 8 hours under the same conditions, the formulation further provides KT ₅₀ from 21 to ₆₀ minutes. Typically, the formulation disclosed herein provides KT ₅₀ from 7.0 to 8.5 minutes after substantial depletion of the formulation, and from 22 to 33 minutes after 8 hours.

In one embodiment, the composition may further contain water. Water is typically added to facilitate mixing and to shape the composition. Once the composition is formed, the water can be removed by drying; however, some water may remain in the composition and the object after formation.

In addition, chlorfluazuron, renafenone, sevomethrin, and phenylephrine can be used in similar compositions as those described above for metronidazole and tetrafluoroethylene. In these compositions, chlorfluazuron, renafenone, sevomethrin, and phenylephrine can be used alone or in combination with other active agents mentioned herein (including metronidazole and tetrafluoroethylene).

Those skilled in the art will understand that the composition of this invention can be prepared in various ways and then incorporated into an object. Typically, the flammable bulk material and binder can be ground into powder, combined, and then added to water containing the pyrethroid and other materials such as dyes, perfumes, binders, and preservatives. The resulting insecticide composition is in the form of dough and can be formed into an object.

The object can be any object, including conventional forms of coils or rods, but may also include other configurations. For example, the composition may be provided in a vial or container for combustion therein. This vial or container may be partially open to the atmosphere. For example, it may have an opening that exposes the insecticide composition, or the insecticide composition may be located in a chamber of the object with a vent to allow the evaporated pyrethroid to be released into the atmosphere.

It should be understood that the object can take the form of a coil or a rod. The coil can be formed into a planar circle, hexagon, or other spiral shape, and its formation involves rolling or extruding a sheet of dough formed by the method described above to a uniform thickness, then cutting out the coil and baking it to remove moisture. The coated rod can be made by wrapping a thin wooden stick with dough formed by the method described above.

Alternatively, molding or other forming methods (e.g., vacuum forming) can be used to shape the dough formed by the methods described above.

In one embodiment, the insect repellent composition is molded into an object. In another embodiment, a base is molded into the object. Optionally, a base may be provided together with the object for insertion prior to use. For example, a small hole may be incorporated into or formed in the object to position it on a vertical pin, forming part of a support for the object. This support may also form a dish or plate for collecting ash from burned objects.

The molded object according to the invention can be formed into any suitable shape. The object can be helical or malleably formed into a rod, disc, cylinder, prism, sphere, cone, or conical shape. A conical shape has a polygonal base with n sides, where n is 3, 4, or more, i.e., 3 to 8, preferably 3 to 6, typically 3 (i.e., a triangular base cone) or (i.e., a square base cone). A prism has a polygonal base with n sides, a second base that is a translational copy of the base, and n other faces connecting the corresponding sides of the second base, where n is 3, 4, or more, i.e., 3 to 12, preferably 4 to 8, typically 4 (i.e., a cubic or rectangular prism), 6, or 8. The object can be truncated, for example, a truncated cone or conical shape. The object can be of any shape, provided that it can be ignited and maintained in a configuration where combustion can continue for a desired period of time. Those skilled in the art will understand that certain shapes are easily molded, and the molding process can be specified to deviate from a generally described shape. For example, a molding method may specify the formation of a groove in the object to receive support elements during the molding process or to aid in demolding. For example, if the object is generally conical or generally pyramidal in shape, the provision of a groove can also aid in the stacking of the molded object. Typically, the groove is provided in the base, but if desired, recesses, indentations, shallow depressions, or openings can also be formed on the top surface or sides.

Those familiar with this technique will understand that some shapes may require support to ensure continued combustion, while others, such as cones or cylinders, are self-supporting and can burn without tipping over, provided they are placed on a non-ignitable surface. The shape of the object can be adjusted, for example, by adding flanges to increase the contact area with the supporting surface, making it more stable. The shape can also be adjusted for other purposes, such as incorporating ear flaps for easier handling. The object can include grooves on any surface or can be patterned in any way. The object can be formed by combining two or more pieces in any suitable manner.

In one embodiment, the molded object is self-supporting.

In one embodiment, the molded object may be generally tapered. It should be understood that the generally tapered object may be truncated and may include recesses on the bottom surface (if truncated) or the base or both, and may include other structural elements described above.

Typically, the weight of the molded article according to the invention ranges from 0.5 to 5.0 grams, preferably 0.8 to 3.0 grams, and most preferably 1.0 to 2.0 grams. The weight is affected by the generally required burning time. In one embodiment, the molded article generally needs to burn for ≥10 to 60 minutes, preferably ≥15 to 40 minutes, and most preferably ≥20 to 30 minutes. In a particularly advantageous embodiment, the invention provides a small and fast-burning product that provides rapid and long-lasting insect (e.g., mosquito) protection. A relatively small cone burns faster than a larger cone formulated in the same manner. The smaller cone provides faster insect protection than the larger cone, although the protection time is slightly shorter. The burning time is also affected by the formulation of the cone. For example, adding an accelerator will increase the burning time. The choice of flammable bulk materials will also affect the burning time. Accordingly, these parameters should be selected to achieve a burning time that provides adequate protection. When immediate protection is more important, a shorter burning time should be selected, while when the emphasis is on the duration of protection, a longer burning time should be selected.

The weight of the molded part is also affected by the form in which the pyrethroid is provided. When the pyrethroid is provided in emulsion form, although not to be bound by theory, it is generally believed that the amount of surfactant and/or organic solvent present in the emulsion is sufficient to give the insecticide composition an oily texture, making it difficult to mold. However, this can be solved by increasing the size of the product, which in turn allows it to be molded into a self-supporting shape, such as the desired cone shape.

In one embodiment, an object containing an emulsifier (such as a pyrethroid provided in emulsion or microemulsion form) can be formed into a self-supporting shape such as a cone.

The amount of pyrethroid in each molded object can be selected to achieve the desired release rate. This is more or less determined by the size of the molded object. Those skilled in this art can adjust the composition of the compound and the size and shape of the molded object to achieve the desired release rate of pyrethroid at the predetermined combustion time.

The present invention also provides a kit comprising an object including an insect repellent composition and a base for supporting the object.

In one embodiment, the object may have a degree of looseness, and the base may be adapted to insert the object. In particular, the base typically includes a portion adapted to pass through the object and a portion that supports the object when it is secured to the base. However, the base may also include support elements that do not pass through the object but can still support it.

In one configuration, the object may include a hole, wherein the base is adapted to engage the hole. In an alternative or additional configuration, the holder may include a dish or plate for collecting the ash from the burned object.

The kit may further include instructions for use.

The method of this invention involves igniting an insect repellent composition to repel insects. Typically, this method involves igniting one or more objects containing a composition according to this invention.

Those familiar with this technique will understand that insects may be killed because pyrethroids are insecticides. They will further understand that knocking down or killing insects serves to repel them, thus protecting people in areas protected by the burning materials of this invention from bites. Those familiar with this technique will also understand the effects of exposure on insect behavior, such as confusion and disorientation, leading to an uncoordinated landing on human and/or animal targets, and thus also serving the purpose of repelling insects.

In one embodiment, the insect repellent composition can be ignited in an enclosed space. In particular, the insect repellent composition can be ignited indoors, such as in a bedroom when the occupant is sleeping, to repel insects.

The number and spacing of the molded objects according to the invention can be determined by many factors. If used indoors, the size and shape of the room will affect the number of objects required in each room. If used in a partially open space, the size and shape of that space will affect the number of objects required in each space. This is also affected by factors such as the degree of airtightness of the space and the presence of wind. The size of the molded object and its pyrethroid content will also affect the number of objects required in each room or space. Typically, the molded objects according to the invention can provide a coverage of ≤12.0 ^m² in enclosed rooms, which is a typical room size.

The components of this invention are active against a wide variety of insects, particularly flying insects. In one embodiment, the insect is selected from one or more species of a group consisting of mosquitoes, midges, sand flies, black flies, houseflies, jungle flies, horseflies, honeybees, wasps, ants, cockroaches, leeches, ticks, and mites.

In one implementation, the insect is a mosquito.

Those familiar with this technique should understand that mosquitoes in some areas have developed resistance to pesticides commonly used in those regions.

Those familiar with this technique will understand that components of this invention, providing long-term protection, may be particularly useful in situations where it is necessary to minimize or even avoid exposure to mosquitoes. Example materials and methods.

Metformin and tetrafluoromethrin are supplied in the form of SumiOne ^™ 5% emulsion and Detrans ^™ 1209 5% microemulsion, respectively, both sourced from Sumitomo Chemical Asia (Singapore). Bayfuning is available as an industrial-grade or analytical standard, sourced from Sumitomo Chemical Company, LTD (JAPAN).

Standard mosquito coils containing 0.2% w/w of Pynamin Forte (also referred to in this document as Malaysian Standard Reference Coiled Mosquito Coils) are available from retail stores. These mosquito coils are recommended by the Malaysian Standards Department, see Household Insecticide Products - Physical, Chemical and Biological Efficacy Requirements – Mosquito Coils (Fourth Edition) MS 23: PART 1:2006 Malaysia: Department of Standards Malaysia; 2006.

The paper-based insecticide (also referred to in this article as Bayer Powder-impregnated paper) was obtained from Godrej, Indonesia, for comparative purposes. The paper was burned for about three minutes and then impregnated with about 4 mg of Bayer Powder.

Female Culex quinquefasciatus mosquitoes are 2-5 days old. This mosquito is a susceptible strain obtained from a laboratory.

Resistant wild mosquitoes ( Aedes aegypti ) were collected from a dengue fever hotspot in Gombak district, Selangor, Malaysia (February/March 2017).

Unless otherwise stated, other chemicals are obtained from standard commercial suppliers.

Unless otherwise specified, the following examples use a large room (L4.0m x W3.0m x H2.5m = ^30m³ ). Example 1 formulation and distribution.

Table 1 below lists the components present in pesticide compositions. Table 1

Weigh the flavoring powder, coconut shell powder, and α-starch, and mix them thoroughly to form a powder mixture. Weigh the dehydrated sodium acetate and place it in a beaker, then add water to form a clear solution. Next, add the dehydrated sodium acetate solution and the SumiOne ^™ 5% EC (containing 5.05% w/w SumiOne) to the powder mixture. Rinse the beaker containing the solution with water, and then add that water to the powder mixture as well. Knead the resulting mixture into a dough, and while the dough is still wet, mold it using a tapered mold (the inner diameter of the mold should provide a cone 3.00 cm high and 1.5 cm wide at its widest point). The target weight for each cone should be 2.50 to 2.70 g when wet (1.30 to 1.50 g when dry). Dry the wet cones in an oven at 60ºC until they reach a stable weight (approximately 3 hours).

It should be understood that the amount of water added to the powder mixture varies depending on the base material used.

The above procedure describes only one possible method for preparing an insecticide composition. Other known methods for preparing insecticides may also be used, provided they produce insecticides with the compositions provided in Table 1. Example 2 Laboratory Tests

Subsequently, in a large room with four walls and a volume of ^30m³ , a dried cone containing ~5mg of methionine/cone (prepared according to the procedure in Example 1) was compared with Pyrzophos-impregnated paper and Malaysian standard reference coil mosquito coils (containing 0.20% w/w Pynamin Forte). The test plan used free flight, and the procedures for each of the above are detailed below. Mosquito Coil (Malaysian Standard) Test Method

A smoldering mosquito coil was clipped to a metal stand, and after recording its initial weight, it was immediately placed in the center of a large room. Then, 100 female mosquitoes (Culex pipiens quinquefolius) were immediately released into the room. The number of mosquitoes knocked down (upside down) was counted at appropriate intervals of 120 minutes. At the end of the observation period, the weight of the mosquito coil was weighed again to calculate the burning rate. No fan was used in this test, and each of the following tests was repeated 3 to 5 times. Conical Test Method

Evaluate the knockdown efficiency of the dried cone after 0, 4, and 8 hours in the large chamber. Before testing, place a cone on a metal disc in the center of the chamber and ignite it. Extinguish the flame quickly and allow it to smolder until the entire cone is used up.

In the initial test immediately following ignition, 100 female mosquitoes (Culex pipiens quinquefolius) were released into the chamber. Four and eight hours after the initial ignition, another batch of 100 female mosquitoes was released. In each case, the number of mosquitoes knocked down (upside down) was counted at appropriate intervals from the release time up to 120 minutes, and the KT ₅₀ value was evaluated using Probit Analysis. Dipping Paper Test Method

The knockdown efficiency of ~4mg Bayven paper was evaluated after being placed in a large Peet Grady chamber at 0, 4, and 8 hours. Before testing, a sheet of paper was placed on a metal disc located in the center of the chamber, and only one side was ignited. The flame was quickly extinguished, allowing it to flash burn until the entire sheet of paper was completely burned.

In the initial test immediately following ignition, 100 female mosquitoes (Culex pipiens quinquefolius) were released into the chamber. Four and eight hours after the initial ignition, new batches of 100 female mosquitoes were released. In each case, the number of mosquitoes knocked down (upside down) was counted at appropriate intervals of up to 120 minutes from the release time, and the KT ₅₀ value was evaluated using Probit Analysis. Results

The test results are summarized in Table 2. Table 2

The test data above confirms that the cone provides mosquito protection for up to 8 hours from the time it is ignited. In contrast, while paper provides effective immediate protection while burning, its effectiveness is limited after ignition. As shown, the coil takes a considerable amount of time before it begins to provide effective protection.

The experiment in Example 2 was repeated, but compared to a Malaysian standard reference coil mosquito coil containing 0.6% w/w Pynamin Forte. It was found that at least 7.20 mg of Pynamin Forte was needed in the composition to achieve the same or lower KT ₅₀ value as the reference product. Example 3

A comparison of cone-shaped mosquito coils containing metronidazole with those containing other vapor-activated pyrethroids and Malaysian standard coil mosquito coils. Conical

Prepare cones containing one of the following: metronidazole, tetrafluoromethrin, phenylephrine, and profluthrin, using the formulation and method of Example 1 (dried at 60ºC). Adjust the amount of active agent in each cone (based on pure active agent) and list it in Table 3 below. Test Methods

The test method described in Example 2 was repeated for each cone containing metronidazole, tetrafluoromethrin, phenylephrine, and propargite, but data were collected only once, 8 hours after initial ignition. Results

The results of this test are shown in Table 3 below. Table 3

As shown in Table 3, tetrafluoromethrin exhibits greater activity than other tested pyrethroids. At least, metronidazole, tetrafluoromethrin, and phenylephrine provide efficacy for up to 8 hours at a range of concentrations (based on efficacy measured in comparison with the KT ₅₀ value of standard coiled mosquito coils). See Example 1 for susceptibility testing of laboratory and Gombak strains of Aedes aegypti .

This study compared the susceptibility of laboratory and wild Aedes aegypti mosquito strains (collected from Gombak district, Selangor, Malaysia, a dengue-endemic area) to standard Malaysian coil mosquito coils. The tests were conducted in a Peet Grady chamber (L1.8m x W1.8m x 1.8m = ^5.8m³ ) using Pynamin Forte coil mosquito coils at various concentrations. Coil mosquito coil testing method.

A sheet of white paper was placed on the floor of a 5.8 ^m³ Peet Grady chamber. A smoldering mosquito coil was clipped to a metal holder, and after recording its initial weight, it was immediately placed into the Peet Grady chamber. Then, 100 female mosquitoes were immediately released into the chamber. Landing (landing and resting on the floor) and knocked-down (upside down) mosquitoes were counted at appropriate intervals of up to 120 minutes. Probit Analysis was used to analyze and evaluate the landing and knock-down times (LT ₅₀ and KT ₅₀ ) for 50% of the test population. Results

^#1 No bioavailability testing was conducted.

^#2 did not achieve a 50% landing or knockdown rate for the test group within the time limit (i.e., within 120 minutes). Table 4

Test data showed that wild Aedes aegypti mosquitoes exhibited significantly lower susceptibility (i.e., higher tolerance) compared to laboratory susceptibility strains. Example 4

This study evaluated the efficacy of higher-dose methamidophos and tetramethrin cone-shaped inhalers against tolerant Aedes aegypti mosquito strains in the wild. Both active agents were compared to standard Malaysian coil mosquito coils. Conical Inhaler

To manufacture cone-shaped mosquito coils containing 0.35% w/w or 0.60% w/w (based on pure active ingredient) of either methamidophos or tetramethrin, using the formulation and method of Example 1 (dried at 60ºC). This is achieved using the same amount (0.35% w/w) of coconut shell powder as used in the formulation of Example 1, or a reduced amount (0.60% w/w). Test Method for Coil-Type Mosquito Coils

A sheet of white paper was placed on the floor of a 0.3 ^m³ glass chamber, and a 0.5 g coil of mosquito coil was fixed to its holder. Both ends were then lit. Once the coil had completely burned, 20 female mosquitoes were released into the chamber through a sliding door, and the timing was started. Landing and knockdown were observed and recorded at appropriate 30-minute intervals. Landing time (LT ₉₀ ) and knockdown (KT ₅₀ ) values were evaluated using Probit analysis. Conical test method.

A sheet of white paper was placed on the floor of a 0.3 ^m³ glass chamber, and a cone-shaped insecticide (0.35% w/w or 0.60% w/w of methamidophos or tetrafluoromethrin) was placed on a metal plate, with its tip ignited. The flame was quickly extinguished, allowing the cone to smolder until completely burned. Twenty female mosquitoes were released into the chamber through a sliding door, and the timing was started. Landing and knockdown were observed and recorded at appropriate 30-minute intervals. Landing time (LT ₉₀ ) and knockdown (KT ₅₀ ) values were evaluated using Probit analysis. Results

The results are provided in Table 5 below. Table 5

As shown, the coiled mosquito coil failed to provide rapid knockdown of tolerant mosquitoes under these test conditions. However, both dosage levels of Metformin and Tetrafluorometholone provided effective knockdown of mosquitoes and had similar efficacy (95% confidence threshold overlap). Therefore, even if the mosquitoes are from tolerant strains, the cone-shaped type described in this paper is effective in stopping and killing mosquitoes. Example 5: Effect of Burning Rate

In a large chamber (30 m³), cones (~5 mg of metronidazole) with various combustion rates were formulated and evaluated. The combustion rate was accelerated by (a) adding potassium nitrate to change the composition of the cones, and (b) changing the size of the cones. The formulation details are described in Table 6 below. Table 6

The evaluated evaporation rate is ~60%. Test Method for Coil-Type Mosquito Coils (Malaysian Standard)

A smoldering mosquito coil was clipped to a metal stand. After recording its initial weight, the coil was immediately placed into a large room. One hundred female mosquitoes were then immediately released into the room. The time was continuously timed after release to observe the knockdown time. The coil was allowed to burn continuously in the room. The number of knocked-down mosquitoes (upside down) was counted at two-hour intervals. At the end of the observation period, the weight of the coil was weighed again to calculate the burning rate. Conical Test Method

The bioefficiency of the cones from Table 5 was evaluated in the same large chamber at 0 hours (initial), 4 hours, and 8 hours. Before testing, a cone was placed on a metal disc in the center of the chamber floor. The tip of the cone was then ignited. The flame was quickly extinguished, allowing the cone to smolder until the entire cone was burned. a) Initial release of mosquitoes

In the initial step, immediately after ignition, release 10 female mosquitoes into the chamber (0 hours). Release them every 1 minute for a total of 10 minutes. Each release consists of 10 female mosquitoes (total insect count per chamber = 110). b) Delayed release of mosquitoes

Four hours later, a new batch of insects (100 female mosquitoes) was released into the room, and then released again eight hours later.

The knockdown time was measured immediately after the insects were released. The number of mosquitoes knocked down (upside down) was counted after an appropriate time of 2 hours.

The KT ₅₀ value (derived from knockdown data) was evaluated using Probit analysis.

The results are shown in Table 7. Table 7

The test data presented in Table 7 shows that cone-shaped mosquito coils with a burning time of 20 to 30 minutes provide excellent knockdown effectiveness for both immediate and long-term (at least 8 hours) mosquito protection. Cone-shaped coils with shorter burning times still provide protection after a longer period, but to a slightly lower degree. Cone-shaped coils with a burning time longer than 20 to 30 minutes initially provide a slightly lower level of protection. A comparison with the reference coil-shaped mosquito coil shows that all cone-shaped formulations provide sufficient levels of initial and long-term protection. Example 6

Cone mosquito coils containing ~5mg of one of the following: resveratrol, chlorpyrifos, and sevomethrin (using the formulation and method of Example 1), were manufactured and evaluated using a typical room method (in a ^30m³ room). The burning time of the cones of this formulation was 20 to 30 minutes, with an evaporation rate of at least 60%. Test details are described below. Coil-type mosquito coils (Malaysian standard) test method.

A smoldering mosquito coil was clipped to a metal stand. After recording its initial weight, the coil was immediately placed into a large room, and 100 female mosquitoes (Egyptian striped, susceptible strain) were immediately released into the room. The knockdown time was immediately observed after release. The coil was allowed to continue burning in the room. The number of knocked-down mosquitoes (those upside down) was counted at appropriate 2-hour intervals. At the end of the observation period, the weight of the coil was weighed again to calculate the burning rate. Conical Test Method

The bioefficiency of the incense cone of this formulation was evaluated in a large house at 0 hours (initial) and 8 hours. Before testing, one incense cone of the formulation (containing one of the active ingredients) was placed on a metal disc in the center of the room floor. The cone was then ignited from the tip. The flame was quickly extinguished, allowing the cone to smolder until completely burned. a) Immediate release of mosquitoes

For the initial test immediately after ignition (0 hours), 100 female mosquitoes (Aedes aegypti, susceptible strain) were immediately released into the chamber. b) Delayed release of mosquitoes

In the 8-hour delayed release test, 100 female mosquitoes (Aedes aegypti, susceptible strain) were released into the chamber after 8 hours. Knockdown time was observed immediately after release. The number of knocked-down mosquitoes (upside down) was counted at appropriate 2-hour intervals. The KT ₅₀ value (from the knockdown data) was evaluated using Probit analysis. Results

^#1 Delayed Release: After 8 hours, release a new batch of insects (100 female Aedes aegypti mosquitoes) into the chamber. Table 8

Incense cones containing ~5mg of resveratrol, chlorpyrifos, and sevomethrin showed faster knockdown efficiency than Malaysian reference coil mosquito coils at burning rates of 0.09 to 0.14 mg/min.

(without)

Claims (39)

An insecticide composition comprising: a vapor-activated pyrethroid; a combustible bulk material; and a binder; wherein the vapor-activated pyrethroid is selected from one or more of the group consisting of metofluthrin, transfluthrin, dimefluthrin, meperfluthrin, renofluthrin, and heptafluthrin, and the vapor-activated pyrethroid is capable of improving... The pyrethroid is present in amounts with the following release rates: where the pyrethroid is metronidazole, with a release rate from 0.05 to 0.27 mg/min; where the pyrethroid is phenylephrine, with a release rate from 0.15 to 0.45 mg/min; where the pyrethroid is tetrafluoroethylene, with a release rate from 0.05 to 0.50 mg/min; where the pyrethroid is cyfluthrin, with a release rate from 0.04 to 0.40 mg/min; where the pyrethroid is renafenone, with a release rate from 0.05 to 0.50 mg/min; and where the pyrethroid is heptafluoroethylene, with a release rate from 0.05 to 0.50 mg/min. The composition of claim 1, wherein the pyrethroid is metronidazole and the release rate is from 0.05 to 0.27 mg/s. The composition of claim 1, wherein the proposed pyrethroid is tetrafluoromethrin and the release rate is from 0.05 to 0.50 mg/s. The composition of claim 1, wherein the proposed pyrethroid is phenylethylamine and the release rate is from 0.15 to 0.45 mg/s. The composition of claim 1, wherein the proposed pyrethroid is chlorpyrifos and the release rate is from 0.04 to 0.40 mg/s. The composition of claim 1, wherein the proposed pyrethroid is renafenone and the release rate is from 0.05 to 0.50 mg/s. The composition of claim 1, wherein the proposed pyrethroid is heptafluthrin and the release rate is from 0.05 to 0.50 mg/s. The composition of claim 1, wherein: metronidazole is present in an amount of 0.35 to 0.66% w/w; and/or phenylephrine is present in an amount of 0.56 to 1.00% w/w; and/or tetramethrin is present in an amount of 0.24 to 3.00% w/w. As in claim 1, the pyrethroid is provided in the form of the compound itself. As in claim 1, the proposed pyrethroid is provided in the form of an emulsion or microemulsion. As in claim 1, wherein the combustible bulk material is in powder form of a substance selected from one or more of the group consisting of wood, sawdust, paper, cardboard, coconut shell, powder made from leaves or other nut shells, jute, bagasse, rice husk, tea residue, coffee grounds, charcoal, and pyrethrum residue. As in claim 11, the combustible bulk material is one or more substances selected from the group consisting of wood flour, coconut shell powder, charcoal powder, and pyrethrum residue. As in component of claim 1, wherein the flammable bulk material is supplied in an amount of 70 to 90% w/w. As in the composition of claim 1, wherein the binder is selected from one or more materials chosen from joss powder, α-starch, makko powder, tabu powder, carboxymethyl cellulose, guar gum, cassava starch, tamarind starch, and tamarind kernel powder. As in the composition of claim 14, wherein the binder is a fragrance and/or α- starch. As in the composition of claim 1, wherein the binder is provided in an amount of 5 to 40% w/w. As in component 1 of claim, it further comprises a preservative. As in the composition of claim 17, wherein the preservative is selected from one or more materials chosen from sodium acetate dehydrate, potassium sorbate, and sodium benzoate. As in the composition of claim 17, wherein the preservative is provided in an amount of 0 to 1.0% w/w. The composition of claim 1 further comprises at least one emulsifier. The composition of claim 1 further comprises at least one fuel accelerator or oxygen-generating agent. The composition of claim 1 further comprises at least one flame retardant. The composition of claim 1 further comprises at least one colorant and/or fragrance. A method for preparing an insecticide composition as defined in claim 1, comprising the steps of: a) providing a vapor-activated pyrethroid; b) providing a combustible bulk material; c) providing a binder; and d) optionally providing a preservative; e) optionally providing at least one additive selected from the group consisting of emulsifiers, fuel promoters or oxygen suppliers, flame retardants, colorants, and fragrances; and f) mixing the vapor-activated pyrethroid, the combustible bulk material, and the binder with water, and optionally the preservative and/or at least one additive. The method of claim 24 further includes the step of forming the components into an object. An article comprising an insecticide composition as defined in claim 1, wherein the article is in the form of: a coil; a rod; the provided composition contained in a vial or container and configured to burn therein; or the provided composition is in a chamber of the article having a vent configured to allow evaporated pyrethroids to be released into the atmosphere. The item in claim 26, wherein the composition comprises a pyrethroid in emulsion or microemulsion form. Such as the object in request item 26, where the object is self-supporting. The object in request item 28 is approximately conical in shape. Items as described in claim 26, weighing between 0.5 and 5.0 grams. Items as described in claim 30, weighing between 0.8 grams and 3.0 grams. The item described in claim 31, for example, weighs between 1.0 and 2.0 grams. Items such as those in claim 26 are configured to burn for 10 to 60 minutes. The item in claim 33 is configured to burn for 15 to 40 minutes. The item in request item 34 is configured to burn for 20 to 30 minutes. A kit comprising an object containing an insect repellent composition as defined in claim 26, which is not self-supporting, and including a base for supporting the object. A method for repelling insects, wherein the method involves igniting an insect repellent composition as defined in claim 1 to repel insects. As in the method of claim 37, the insect is selected from one or more species of a group consisting of mosquitoes, midges, sand flies, black flies, houseflies, jungle flies, horseflies, honeybees, wasps, ants, cockroaches, leeches, ticks, and mites. The method described in claim 38, where the insect is a mosquito.