Accepted answer
They are not the same word, and the gap between your two vials is almost certainly a category difference plus a sterility test, not a disagreement about chemistry.
BUD is not expiry
An expiration date belongs to a manufactured product and is supported by stability studies on that formulation in that container closure, run to a protocol, with assay data at each timepoint. A beyond-use date is assigned to a compounded preparation and, under the sterile-compounding chapter, is primarily a microbiological limit — a statement about how long the preparation can be relied upon to remain sterile given how it was made, not a statement that the drug is still at label strength. Those are different guarantees. A vial within its BUD is presumed sterile; it is not thereby proven potent.
Where the numbers come from
The revised sterile-compounding chapter sorts preparations into categories, and the category plus a small number of facts sets the maximum BUD. Simplified, for aseptically processed preparations:
| Category and how made | Room temp | Refrigerated | Frozen |
|---|
| Category 1 (compounded in an unclassified segregated area) | 12 hours | 24 hours | — |
| Category 2, from nonsterile components, no sterility test | 1 day | 4 days | 45 days |
| Category 2, from sterile components only, no sterility test | 4 days | 10 days | 45 days |
| Category 2, from nonsterile components, sterility test passed | 30 days | 45 days | 60 days |
| Category 2, from sterile components only, sterility test passed | 45 days | 60 days | 90 days |
| Category 3 (extra controls, testing and stability data) | up to 60 days | up to 90 days | up to 180 days |
Read your two vials against that. A preparation made by dissolving a nonsterile powder and filtering is "from nonsterile components". Without a sterility test that caps at 4 days refrigerated, which nobody is shipping. With a passing sterility test it reaches 45 days refrigerated. To get to 90 days refrigerated you are in Category 3 territory, which is a substantially heavier regime: additional environmental and personnel controls, sterility and bacterial endotoxin testing, and — the part that matters here — documented stability data supporting the assigned date, not just a microbiological argument.
So the honest reading of your two vials is that the 28-day pharmacy is sitting comfortably inside a Category 2 sterility-tested envelope, and the 90-day pharmacy is either operating a Category 3 programme, or has assigned a date its process does not support. Both are possible. The way to tell them apart is to ask, in one sentence: "which category was this preparation assigned, was a sterility test performed and released on this lot, and what stability data supports the assigned BUD?" A Category 3 operation answers with documents. The other kind answers with adjectives.
PCAB
PCAB is the Pharmacy Compounding Accreditation Board, now operating as a compounding-specific accreditation service of the Accreditation Commission for Health Care. It is voluntary, third-party, and it audits the quality system: written master formulation and compounding records, personnel training and competency including gloved-fingertip and media-fill testing, environmental monitoring, cleaning and garbing procedures, equipment calibration, ingredient sourcing and COA review, and BUD assignment rationale. Surveyors visit the site. That is a real audit, and an accredited pharmacy has demonstrably been looked at by someone who understands the chapters.
What it is not: it is not FDA approval of any product, it does not test your specific vial, and it does not make the preparation a licensed drug. Accreditation tells you the process was audited on a date. Release data tells you about the thing in your hand. You want both, and only one of them is a marketing phrase.
Verify the claim rather than accept it — accreditation status is checkable with the accreditor, and "USP 797 compliant" is self-asserted by definition, since nobody issues 797 certificates.
edited 25 Jan 2026 by tyndall_haze — added the placebo-arm figures
6The one-sentence question at the end is the whole answer. Category, sterility release, stability basis. – vial_five 6 months ago 5Worth adding that BUD restarts nothing on first puncture. In-use limits are a separate and usually shorter clock. – tobias_maartens 5 months ago add a comment