Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Having -c- – wherein x is chalcogen – bonded directly to...
Reexamination Certificate
2002-02-06
2003-12-09
Pryor, Alton N. (Department: 1616)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Having -c-, wherein x is chalcogen, bonded directly to...
C514S531000, C514S717000
Reexamination Certificate
active
06660768
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to compositions for controlling ectoparasites. Specifically, the invention provides parasitical pyrethroid- and pyrethrin-containing formulations comprising solvent systems containing glycol ethers and/or terpenes.
BACKGROUND OF THE INVENTION
Pyrethrins are natural compounds extracted from tropical strains of chrysanthemum flowers (
Pyrethrum cinerariaefolium
). Pyrethroids are synthetic analogs of pyrethrins. Both pyrethrins and pyrethroids have been used as insecticides for controlling ectoparasites (e.g., fleas, flies and ticks) infestations on animals as described e.g., U.S. Pat. No. 4,020,181. A preferred pyrethroid for this purpose is permethrin.
For purpose of administration, the pyrethroid or pyrethrin typically is formulated in a liquid carrier and then applied topically to an animal in need of relief from fleas or other ectoparasites. Desirable carrier substances are solvents that can be mixed with the active agent to provide formulations that can be poured onto an animal. Carriers substances for pyrethroids and pyrethrins have included, for example, aromatic petroleum products such as xylene and toluene, cyclohexamine, alcohols, corn oil, eucalyptus oil and alkyl glycol ethers. While most prior art pyrethroid-containing insecticidal formulations contain only up to 50% by weight of pyrethroid, U.S. Pat. No. 5,236,954 discloses pyrethroid formulations, in particular permethrin formulations, containing permethrin concentrations greater than 50% by using an alkyl glycol ether such as diethylene glycol monomethyl ether. An insecticidal composition having such a high concentration of active ingredient allows for small, easily applied and yet effective doses.
Concentrations of more than 50% by weight active ingredients make topical application more convenient and more aesthetically acceptable. The higher the concentration, the smaller the dose for effective ectoparasite control. A small dose can be applied to a relatively small region of the skin, thus preventing the host from being covered with solvent. This formula and method of application is particularly useful for treating domestic companion animals such as dogs because the animal will not drip solvent or feel sticky when petting occurs immediately after application. Such small doses can be applied without the treated animal being made aware thus easing administration. Although the composition is applied as one or more small doses to a localized region on the animal, the pyrethroid translocates to effectively control ectoparasite infestation over relatively all of the animal. Formulations containing more than 50% by weight of a pyrethroid thus obtain many advantages not present in formulations having a maximum concentration of only up to 50% by weight of the total formulation.
With a larger concentration of active ingredient, such as for example a 65% or greater solution of permethrin, there is not a large amount of solvent present in the formulation, and it has been discovered that pyrethroids and pyrethrins can crystallize out of solution at lower temperatures, e.g., below about 20° C. This is problematic, as it means that the concentration of the pyrethroid or pyrethrin in solution and available for administration to the animal is lessened. Accordingly, there is a need for a solvent system that prevents or minimizes the crystallization of pyrethroids or pyrethrins at lower temperatures.
There is also a need to develop formulations that have a longer period of efficacy than is available from products currently on the market. Products that are efficacious for longer periods of time obviously are desirable as they are more cost effective and will require fewer applications over time to provide effective protection.
SUMMARY OF THE INVENTION
The present invention fulfills this need by providing materials and methods for controlling ectoparasite infestations.
One aspect of the invention provides a parasiticidal composition for topical application to an animal that comprises a pyrethroid or a pyrethrin and a carrier, wherein said carrier comprises a terpene, such as d-limonene. In another embodiment of the invention, the carrier also comprises an alkyl glycol ether. Preferred alkyl glycol ethers include propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and/or diethylene glycol monomethyl ether. Particularly preferred compositions contain a pyrethroid or pyrethrin in an amount greater than 50% by weight of the total composition. Even more preferred are compositions containing a pyrethroid or pyrethrin in an amount at least about 65% by weight of the total composition. Preferably the pyrethroid is permethrin.
DETAILED DESCRIPTION OF THE INVENTION
All references cited herein are hereby incorporated in their entirety by reference.
The invention provides compositions for controlling ectoparasites that can be found on animals, in particular domestic animals including dogs and cats, but also horses, as well as on food-producing animals such as cattle, sheep and swine. The compositions can be used to treat ectoparasites including fleas, ticks, mange, mites, mosquitoes, nuisance and biting flies, lice, anthropod vectors of disease, as well as internal parasites, e.g., heartworms, hookworms and helmiths.
The compositions of the invention comprise a pyrethroid or a pyrethrin and a carrier comprising a terpene or terpene derivative or a combination of a terpene or terpene derivative and another carrier such as an alkyl glycol ether. Surprisingly, it has been found that when a terpene, such as d-limonene (CAS #5989-27-5), is used as the carrier, crystallization can be minimized and/or avoided. In a preferred embodiment, the carrier comprises a combination of a terpene and propylene glycol monomethyl ether, or a combination of a terpene and dipropylene glycol monomethyl ether (CAS #107-98-2). Preferably the composition comprises from about 30% to about 70% by weight of the terpene or the terpene-alkyl glycol ether combination.
Pyrethroids that can be used to practice the invention include permethrin, phenothrin, acrinathrin, allethrin, bioallethrin, bifenthrin, bioresmethrin, cycloprothrin, cypermethrin, cyhalothrin, lambda cyhalothrin, cyfluthrin, cyphenothrin, tralomethrin, tralocythrin, deltamethrin, empenthrin, fenpropathrin, kadethrin, prallethrin, pyrethrins, resmethrin, sluvalinate, tefluthrin, tetramethrin, transfluthrin, fluvinate, flumethrin and fenvalerate. The most preferred pyrethroid for use in this invention is permethrin (CAS #52645-53-1). Permethrin has a molecular weight of 391.28 grams/mole and technical permethrin comprises from about 25 to 80% cis isomer and from about 20 to 75% trans isomer by weight. In the insecticidal composition of the invention, technical permethrin is suitable and it preferably has a minimum amount of the trans isomer of about 45% by weight and a minimum amount of cis isomer of about 35% by weight.
The ectoparasiticide compositions according to the invention, the concentration of permethrin or other pyrethroid typically is from about 30 about 95% by weight, with preferred level being at least about 45%, even more preferred from 50-75% (by weight). The remaining portion of the composition is the carrier substance.
In addition to d-limonene, other terpenes suitable for use in the claimed invention include (&agr;-pinene, &bgr;-pinene, &bgr;-myrcene and terpinolene. In addition, terpene derivatives, or terpenoids, may also be used as the carrier or as one component of the carrier. As used herein, the terms “terpene derivative” or “terpenoid” include terpene alcohols such as geraniol, terpineol and linalool, terpene aldehydes such as citronellal, and terpene ketones such as pulegone, all of which are suitable for use as the carrier or as one component of the carrier in the compounds of the claimed invention.
The terpene, or the terpene alcohol, aldehyde or ketone, can be used as the sole liquid carrier in the compositions of this invention. Alternatively, the carrier can comprise a combination of the terpene or terpen
Endris Richard G.
Rose Shirley Maxine
Rose Wayne B.
Pryor Alton N.
Rose Shirley Maxine
Schering-Plough Animal Health Corporation
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