Abstract: A polymeric device and method for the control of insects on animals is disclosed. The device is in the form of an ear tag or other shape which can be attached to an animal using known techniques. A unique polymer/insecticidal formulation is provided by combining an ectoparasiticidal active compound, such as one or more organophosphates, carbamates, pyrethroids and organochlorines, with a polyurethane polymer. The polymer is the reaction product of 4,4'-diphenylmethane diisocyanate, polytetramethylene glycol and 1,4-butanediol. By utilizing the particular polymers described, high loadings of insecticides are possible and the resulting product shows no tendency to exude insecticide during prolonged storage. The product made according to the invention can provide effective control of horn flies on cattle for six months or more utilizing a single ear tag or the like where it would take two tags constructed according to the prior art to achieve comparable results.

Abstract: A polymeric device and method for the control of insects on animals is disclosed. The device is in the form of an ear tag or other shape which can be attached to an animal using known techniques. A unique polymer/insecticidal formulation is provided by combining an ectoparasiticidal active compound, preferably an organophosphate, with a polyurethane polymer. The polymer is the reaction product of 4,4'-diphenylmethane diisocyanate, polytetramethylene glycol and 1,4-butanediol. By utilizing the particular polymers described, high loadings of insecticides are possible and the resulting product shows no tendency to exude insecticide during prolonged storage. The product made according to the invention can provide effective control of horn flies on cattle for six months or more utilizing a single ear tag or the like where it would take two tags constructed according to the prior art to achieve comparable results.

Abstract: This invention relates to medically useful compositions, each comprising in intimate physical combination: (a) one or more of certain organophsophorus compounds, (b) porous solid particles of a polyvinylic resin, and (c) one or more of certain styrene/maleic anhydride copolymers, each of said compositions being characterized by the property of protecting the organophosphorus compound from adverse effects of materials which contact said composition, yet releasing the organophosphorus compound at a controlled rate to an aqueous liquid in contact with said composition.