This educational tool is provided by Epicur Pharma, a division of Stokes Healthcare Inc., an FDA-registered outsourcing facility that produces compounded animal drugs under CGMP. Because the draft directly affects our operations and the veterinary practices we serve, we have a commercial interest in its outcome. We encourage every user to review the draft. We built this page to help veterinarians share their own views with FDA. We do not submit comments for you, and your letter should reflect your own views and experience.
This is not GFI #256. That guidance is already in effect. #256B is a new draft covering 503B outsourcing facilities and the office-use drugs they supply. FDA plans to fold it into GFI #256 once it's final.
Draft Guidance #256B proposes the circumstances under which FDA generally would not take enforcement action when federally registered facilities produce animal drugs from bulk substances under CGMP. As written, it could reduce access to CGMP-produced compounded office-stock medications and create additional costs, waste, treatment delays, and administrative burdens for veterinary practices and animal owners. Only a handful of facilities make compounded animal drugs under cGMP, so without veterinarians, CVM will hear mostly from the facilities themselves.
The central concern is that FDA proposes to apply substantially the same office-stock product list to traditional pharmacy compounding and CGMP production, despite meaningful differences that may include, but are not limited to, manufacturing controls, testing, stability programs, federal oversight and distribution traceability.
This page helps you write your own comment in about five minutes.
CGMP-produced office stock would generally be tied to the same FDA list used for traditional pharmacy compounding under GFI #256, including limitations by substance, species, dosage form, strength, and clinical need. The draft also restricts distribution and transfer between locations.
§ III.BFederally registered facilities would remain responsible for CGMP compliance, FDA registration and inspection, product testing, stability programs, drug listing and labeling, but would receive little additional office-stock flexibility compared with traditional pharmacies operating under GFI #256.
§ I, III.A.10, III.B.8If a compounded drug shares an active ingredient and route with an approved drug, you must document the clinical difference for that patient. Cost is not a valid reason.
§ III.A.5FDA says it will treat group prescriptions as disguised office stock when the quantity makes it "implausible" only that group will be treated.
§ III.A, n.14Read the draft: FDA guidance page · Federal Register notice
Neither pathway makes these compounded animal drugs FDA approved. Important differences may include, but are not limited to, manufacturing controls, testing, federal oversight, traceability, and the evidence supporting expiration dating.
| State-licensed 503A pharmacy under GFI #256 | Federally registered 503B CGMP facility under Draft GFI #256B | |
|---|---|---|
| FDA-approved drugs? | No | No |
| Quality standard | Applicable pharmacy and USP compounding standards, primarily overseen by state boards | CGMP quality systems, with FDA-led drug-quality oversight and routine federal inspection |
| Dating on sterile products | Beyond-use dating established under applicable pharmacy and USP standards; dating varies by preparation and compounding category | Expiration dating assigned under CGMP; where supported by stability data, some products can carry dating of up to one year |
| Ingredient and finished-product testing | Pharmacy-level ingredient and compounding controls under applicable state and USP standards | May include testing of incoming ingredients from qualified suppliers, identity testing, and finished-product release testing against established specifications |
| Traceability and oversight | Primarily overseen by state boards of pharmacy | Subject to FDA CGMP oversight and routine federal inspection, with batch and distribution records supporting investigation and recall |
| Office stock under GFI #256 today | Allowed for drugs on FDA's list or under FDA review | Hospitals stock many sterile 503B products today, and several states require that compounded medications for office use come from a 503B facility |
| Office stock under Draft #256B | No change | Limited to the same FDA list as 503As, plus full cGMP, registration and NDC listing |
General comparison only. Specific requirements and practices vary by facility, product and state.
Consistency and clinical interpretation. Traditional pharmacy compounding generally does not require laboratory potency testing of every finished batch before dispensing. CGMP release testing is designed to confirm that each batch meets established specifications, such as strength. This can provide greater objective assurance of batch consistency and may reduce one potential variable when a veterinarian evaluates treatment response.
As written, Draft GFI #256B could reduce access to CGMP-produced office-stock medications. The flow below shows how relying on the same FDA product list for traditional pharmacy compounding and CGMP production could affect veterinary practices.
Applying the same product list to traditional pharmacy compounding and CGMP production does not recognize the additional testing, stability, quality-system and federal-oversight requirements associated with CGMP production. Without a distinct CGMP pathway, continued investment in some longer-dated, tested office-stock products may become unsustainable. The result could be fewer dependable CGMP-produced options for veterinary hospitals, particularly for sterile, complex and lower-volume medications.
Presently eligible for FDA's interim enforcement-discretion policy while the nomination is reviewed. Because Draft GFI 256B relies on the same list, FDA's eventual decision would affect both the traditional-pharmacy and CGMP pathways. If FDA declines to list the product, it would no longer fall within FDA's stated office-stock enforcement-discretion policy for either pathway.
The product would generally fall outside Draft GFI 256B's stated office-stock policy for federally registered CGMP facilities and GFI 256's stated policy for traditional pharmacy compounding from bulk substances. Access may be limited to patient-specific compounding, leaving no ready office stock for urgent or unpredictable cases.
FDA outcome context. As of October 5, 2026, FDA's dog, cat, and horse office-stock tables contained 101 reviewed-and-not-listed determination entries compared with 33 listed entries: approximately three not-listed outcomes for every listed outcome. Table entries are not a precise count of individual nominations and may combine or distinguish species, dosage forms, and strengths. Products still under review are excluded.
Potential unintended consequences
Bottom line: As written, GFI #256B could limit veterinary access to important compounded medications and reduce the availability of CGMP-produced products with tested, extended expiration dating. Unless the final guidance meaningfully distinguishes CGMP production from traditional pharmacy compounding, veterinary hospitals could ultimately have fewer dependable office-stock treatment options.
Without office stock, you lose the win-win of treating in the clinic: starting care immediately for continuity of care, better patient compliance, and showing clients how to give the medication before they leave.
What should change: FDA should establish a distinct office-stock pathway for federally registered CGMP facilities rather than applying the traditional-pharmacy product list equally to both production systems. Permitting a product under the CGMP pathway should not automatically make it eligible for traditional pharmacy office-stock compounding.
Sources: FDA, List of Bulk Drug Substances for Compounding Office Stock Drugs for Use in Nonfood-Producing Animals; Bulk Drug Substances Currently Under Review; Bulk Drug Substances Reviewed and Not Listed (all updated Oct 5, 2026). Draft GFI #256B, Federal Register, Aug 28, 2026. GFI #256B is a draft guidance and may change when finalized. Covers drugs compounded from bulk drug substances only.
Pick only the ones that reflect your experience. Your letter will cover these and nothing else.
Rough notes are fine. Full sentences work best. Use the prompts below as a guide: pick as many or as few as you like to expand on, and each one adds a starter line to your story.
FDA gives the greatest value to specific, substantive information. In your own words, describe the medication, species, clinical setting, why immediate availability matters, how often inventory expires before use, and what would happen without a dependable CGMP source.
Before you write. Focus on clinical access, timing, product quality, availability and patient consequences. Do not argue that an approved product or patient-specific prescription is undesirable merely because another option costs less; FDA does not treat lower cost alone as a sufficient clinical justification. Do not include patient-identifying information, pet-owner names, contact details, medical records, license numbers or financial information, and do not claim that a compounded product is FDA approved, proven safer or clinically superior unless you have reliable evidence supporting that statement. Where you can, include actual delays, costs or medication waste you have documented.
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Read the entire draft carefully. Correct every factual statement, personalize it with your own experience, delete anything you cannot verify, and make sure the final comment expresses your own views before submitting it under your name.
FDA gives the greatest value to specific, substantive information. Describe your own products, patients, timing needs, hospital operations and likely consequences. A personalized comment is more useful than repeating a general form letter.
Your draft is written by Claude, an artificial intelligence (AI) model made by Anthropic, using only the talking points you select and the information you type. It is a starting point, not a finished comment. Read the whole letter, edit it so it says what you mean in your own words, and delete anything you do not agree with before you submit it. The draft includes a line noting that it was drafted with the help of an AI writing tool. You are the author and signer of your comment.
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Check every statement before you submit. AI can make mistakes, including stating facts, numbers or descriptions of the draft guidance incorrectly. Do not rely on this draft without checking it against the draft guidance itself and your own knowledge and records. Include only experiences that actually happened and statements you believe are true; comments to FDA are submitted under your name to a federal agency. Epicur Pharma does not review or verify letters drafted with this tool, and nothing on this page is legal, regulatory or professional advice.
FDA's official public record is the docket. To ensure FDA can consider your comment as part of that record, submit it through regulations.gov or by mail using the docket number below. File by the current November 27, 2026 deadline unless FDA announces an extension.
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