Veterinary drug formulations for animal health care: An overview

Abstract

Abstract Controlled release dosage forms of drugs have a wide range of applications in veterinary therapeutics and in the control of parasitic diseases of animals. Because of species variations in digestive physiology, in the rate of biotransformation of lipid-soluble drugs, and in the system of management each product must be designed specifically for the target species. Ruminal boluses are a unique dosage form of oral product in that they provide a prolonged duration of drug release. They have particular application in the delivery of anthelmintics, pesticides as feed-through chemicals, and selected trace elements. The pattern of release is generally continuous, but pulsatile release can be an advantage in the control of certain parasitic infections. In the food-producing animals the frequency of drug administration and the avoidance of tissue residues are paramount considerations. Apart from the treatment of acute bovine mastitis, individual animal therapy is limited to the companion animal species. Since these species, like humans, are monogastric it is unlikely that oral dosage forms of therapeutic (including antimicrobial) agents will provide a dosing interval exceeding twenty-four hours. In the development of controlled release dosage forms for these species, ease of administration and parenteral products that are non-irritating to tissues must be given priority. Controlled release parenteral delivery systems, which include implantable devices, are the alternative to continuous intravenous infusion, which is not practical in animals. Insecticide impregnated tags and collars are an exceptional type of drug delivery system.