FDA’s Latest Draft Guidance on Compounding Animal Drugs From Bulk Substances Seeks Industry Input! Comments Due on February 18, 2020

December 3, 2019By Karla L. Palmer

As we stated in our earlier blog post, on November 21, 2019, FDA released another draft guidance addressing compounding of animal drug products from bulk substances.  Recall that FDA first released its draft animal drug compounding guidance in 2015 (blogged about here).  With the release of that draft, FDA also withdrew its 2003 animal drug compounding guidance (Compliance Policy Guide Sec. 608.400).  FDA’s 2015 iteration of the compounding guidance was greeted with about 160 comments from industry.  Based on FDA’s consideration of those comments, it withdrew the draft guidance in 2017, which move likely reflected FDA’s significant struggle with determining its authority over animal drug compounding and the fact that the Drug Quality and Security Act (Title I, the Compounding Quality Act) and FDCA Section 503A by their terms do not apply to animal drug compounding.  Like the 2015 draft guidance, FDA’s latest attempt would exponentially expand FDA’s regulatory authority over veterinary medicine and the animal drug compounding space, which traditionally has been a state-regulated practice.  FDA likely will receive many comments on this latest draft, reflecting, among other issues, an alleged federal usurpation of state authority, and FDA’s overstepping through the use of guidance its limited statutory authority in the animal drug compounding space. Notably, the latest draft seems even more restrictive in terms of what may be compounded for use in animals than FDA’s withdrawn version.

Those interested in commenting on the draft should do so by February 18, 2020.  Comments should be submitted to this docket. (FDA-2018-D-4533).  In the Federal Register notice announcing publication of the draft, FDA states that it is specifically requesting comments on guidance section III.A.5, which provides that if that compounded drug contains the same active moiety as a marketed FDA-approved, conditionally approved or indexed drug, but as a different salt, ester, or other non-covalent derivative, there should be a difference between the compounded drug and the FDA approved, conditionally approved or indexed animal drug or FDA-approved human drug that will provide a clinical difference in the patient and the medical rationale is documented in the proscription.  If the veterinarian compounds the drug, the difference should be noted in the patient’s medical record.  Does this sound familiar?  It reminds this blogger of Congress’ prohibition on “essentially copies” of FDA-approved human drug products pursuant to Federal Food, Drug, and Cosmetic Act Sections 503A and 503B.  Notwithstanding, FDA states it is concerned that compounded versions (salts, esters, or non-covalent derivatives) of these products may affect the “absorption, distribution, metabolism excretion and stability of the compounded animal drug,” all of which factors contribute to a drug’s “safety and effectiveness.”  FDA also notes that compounding an animal drug from a different  salt, ester, ester, or other noncovalent derivative of the same active moiety as a marketed FDA-approved, conditionally approved or indexed animal drug or FDA-approved human drug may impact “incentives for seeking legal marketing status” of a new animal drug, and could serve as a disincentive for new animal drug sponsor to research or otherwise develop new animal drugs.