Short answer first, then the reasoning. The shortage clause is the answer to the second question and it is a subtraction rather than an addition. Both exemptions forbid compounding something that is essentially a copy of a commercially available approved product. A product FDA has listed as in shortage is not treated as commercially available, so listing removed the objection that otherwise blocked compounding. It never created a permission; it withdrew a prohibition, which is why it evaporated the moment the supply fact changed.
My pharmacy stopped supplying with three weeks notice and a letter that explained nothing, so I went and read the statute.
Two things anyone can check: a state licence number for a 503A, and an FDA outsourcing-facility registration for a 503B. Both are publicly searchable, and a pharmacy unwilling to give you either has answered the question.
So the question, as narrowly as I can put it: what actually distinguishes 503A from 503B, in terms of what each may make and from what starting material.
Tell me what I have not thought of.
mike_nyc said:The shortage clause is the answer to the second question and it is a subtraction rather than an addition.
Agreed, and the enforcement dates were staggered by category — 503A first, 503B a few weeks later — because outsourcing facilities have manufactured inventory and clinic contracts to unwind while a 503A makes to order.
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Browse GL Biochemmel_PDX said:My pharmacy stopped supplying with three weeks notice and a letter that explained nothing, so I went and read the statute.
Same position here, arrived at the long way round. They are two different exemptions from the same federal requirements and they buy different things. A 503A pharmacy is regulated primarily by the state board, needs a patient-specific prescription, is exempt from CGMP, and may use a bulk substance that has a USP monograph, is a component of an approved drug, or appears on the 503A bulks list — three independent doorways. A 503B outsourcing facility registers with the FDA, is inspected on a risk basis, must comply with CGMP, may compound for office stock without a patient-specific prescription, and has one doorway to a permitted bulk substance: the 503B bulks list, or the drug shortage list.
From the other side of the consultation, briefly.
503A vs 503B compounding pharmacies for compounded supply — this distinction matters enormously:
| Feature | 503A | 503B |
|---|---|---|
| Regulation | State Board of Pharmacy | FDA-registered |
| Prescription | Required (patient-specific) | Can compound without patient Rx |
| Testing | Varies by state | cGMP required |
| Scale | Small batches | Larger production |
| Quality consistency | Variable | Generally higher |
I strongly recommend 503B facilities. The FDA oversight and cGMP requirements mean more consistent product quality.