On April 14, 2022, FDA issued Guidance for Industry #256 entitled “Compounding Animal Drugs from Bulk Drug Substances.” The GFI describes the agency’s approach to addressing situations where veterinarians need access to compounded unapproved drugs to provide appropriate care for the medical needs of the diverse species they treat. FDA maintains lists of bulk drug substances for compounding office stock for nonfood-producing animals, antidotes for food-producing animals, and sedatives or anesthetics for free-ranging wildlife species. FDA will accept nominations of additional bulk drug substances at any time and will continue to review nominations and update lists.
FDA intends to include a bulk drug substance on either of the lists when:
- There is no marketed FDA-approved, conditionally approved, or indexed animal drug(s) that can be used as labeled to treat the condition;
- There is no marketed FDA-approved, conditionally approved, or indexed animal or human drug(s) with the same active ingredient(s) that could be used in an extralabel manner to treat the condition; and
- FDA has not identified a significant safety concern specific to use of the bulk drug substance in animals.
For bulk drug substances used to compound drugs intended as office stock for nonfood-producing animals, in addition to 1- 3 above:
- Urgent treatment with the compounded drug is necessary to avoid animal suffering or death, or to protect public safety.
For bulk drug substances used to compound drugs intended for use as antidotes in food-producing animals or for use as sedatives or anesthetics for free-ranging wildlife species, in addition to 1-3 above:
- There is sufficient scientific information for the prescribing veterinarian to determine appropriate withdrawal, withholding, or discard time(s) for meat, milk, eggs, or any food which might be derived from the treated animal(s).
Bulk drug substances that do not appear on 1) The List of Bulk Drug Substances for Compounding Office Stock Drugs for Use in Nonfood-Producing Animals, or 2) The List of Bulk Drug Substances for Compounding Drugs for Use in Food-Producing Animals or Free-Ranging Wildlife Species are an enforcement priority for FDA when used to compound animal drugs for office stock.
For bulk drug substances that were nominated and are still under FDA review, FDA generally intends to refrain from taking enforcement action when these bulk drug substances are used to compound a finished drug as described in the initial nomination. These bulk drug substances will be identified on Bulk Drug Substances Currently Under Review.
Bulk drug substances that have been reviewed by FDA and were not included on a list can be found on Bulk Drug Substances Reviewed and Not Listed.
Interested stakeholders may nominate additional bulk drug substances using the nomination procedure described in the appendix to GFI #256.