Compounding is the manipulation of a drug, other than in accordance with the FDA approved label, to make a different formulation of the drug to meet the needs of a specific patient.

Compounding, including formulation in a novel drug delivery system (e.g. transdermal), may impact the absorption and depletion of a drug. The use of a compounded drug may result in drug concentrations that lead to the development of an adverse drug event, including therapeutic failure. In order to minimize the risk of adverse events associated with compounded drugs, the following actions are recommended:

1. The decision to use a compounded drug should be veterinarian (not pharmacy) driven, based on a veterinarian-client-patient relationship.
2. Compounding must be implemented in compliance with the Animal Medicinal Drug Use Clarification Act (AMDUCA) and the FDA Compliance Policy Guide 608.400 titled Compounding of Drugs for Use in Animals. Use of compounded drugs in food animals is accompanied by food safety concerns that preclude their use unless information exists to assure avoidance of illegal tissue residues.
3. Use of a compounded drug should be limited to:
   1. Those drugs for which both safety and efficacy have been demonstrated in the compounded form in the target species;
   2. Disease conditions for which response to therapy or drug concentration can be monitored; or
   3. Those individual patients for which no other method or route of drug delivery is practical. Use of a compounded drug should be accompanied by the same precautions followed when using a drug in its original form, including counseling of the client regarding potential adverse reactions and attention to the potential for unintended human or animal exposure to the drug.

For further information, please contact: Scientific Activities Division, Council on Biologic & Therapeutic Agents.