This one has a reasonably settled answer, so here it is. 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.

KevinCompounds 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.

Ask again with the specifics and you will get a better answer than this one.

PharmacoVig_BOS said:

My pharmacy stopped supplying with three weeks notice and a letter that explained nothing, so I went and read the statute.

Can confirm the pattern PharmacoVig_BOS describes. 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.

FDA inspection results for compounding pharmacies selling compounded supply: you can look up any 503B facility's FDA inspection history on the FDA website.

Check for: Form 483 observations (violations), warning letters, and recall history. A clean inspection record is a strong indicator of quality. My pharmacy has had 0 Form 483 observations in their last 3 inspections.

This is public information. Use it. Link: fda.gov/inspections-compliance-enforcement-and-criminal-investigations