Has anyone dealt with compounded tirz stability at room temperature?

BethLabQueen said:

They are two different exemptions from the same federal requirements and they buy different things.

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to. It is a different legal universe with no pharmacy oversight, no patient relationship and no content guarantee, and conflating the two in these threads helps nobody.

The figures, for anyone assembling their own picture. 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.

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

COA_Karl said:

A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to.

Coming at COA_Karl’s question from a different direction. Resolution therefore closed the doors unevenly, and the asymmetry follows from the bulks lists. For 503B the shortage clause was the only route to these molecules, so that route shut completely. A 503A pharmacy can still argue a doorway via "component of an approved drug" — but only for the substance in the form present in the approved product, which is exactly where the base-versus-salt argument lives, and it does nothing about the copy restriction, which came back into force on resolution.

Worth separating that from compounded supply, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

Happy to go further on any of that.

A narrower follow-up, since the general answer is now clear:

What actually distinguishes 503A from 503B, in terms of what each may make and from what starting material?

Reporting back.

Update: the excursion was survivable and the vial was fine. I now keep a cheap fridge thermometer, which costs nothing and ends the argument.