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ForumsCompounding & FormulationCompounded sema potency testing — HPLC method validation details Page 2

Compounded sema potency testing — HPLC method validation details

HPLC_Greg Tue, Jun 2, 2026 at 12:18 AM 24 replies 814 viewsPage 2 of 5
stefan_berlin
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Jun 2, 2026 at 2:38 AM#6

The figures, for anyone assembling their own picture. The four things to check on any report, in order: does it name your batch, who commissioned it, what method was used, and does it report content as well as purity. A report failing any of those is weak evidence regardless of the percentage on it.

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MikeNYC_runner
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Jun 2, 2026 at 3:32 AM#7

One thing that is still open after Dr.RaviCardio’s answer:

Why a shortage listing created a legal pathway at all, since a shortage is a supply fact rather than a permission?

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PharmD_Rodriguez
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Jun 2, 2026 at 4:27 AM#8
stefan_berlin said:
The four things to check on any report, in order: does it name your batch, who commissioned it, what method was used, and does it report content as…

Adding the part of the answer the thread has not reached. They are not contradictory, they measure different things, and this is the single most common misreading of a certificate. Purity is a relative area measurement: the main peak as a percentage of total peak area in the chromatogram. Content is an absolute mass measurement against a reference standard. A vial can be 99% pure and contain 6.1mg — pure material, overfilled — or 99% pure and contain 3mg, which is pure material and a short fill. Purity tells you what fraction of what is there is the right molecule; content tells you how much of it there is. You need both, and a certificate with only purity is telling you half the story.

Last edited: Jun 2, 2026 at 9:27 AM
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HPLC_Greg
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Jun 2, 2026 at 5:22 AM#9

OP back with an update, since a thread like this is useless without one.

The bulks-list asymmetry was the piece I had missed entirely. It explains why one of my two pharmacies is still arguing it can supply and the other simply stopped.

Last edited: Jun 2, 2026 at 11:22 AM
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tampaLisa73
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Jun 2, 2026 at 9:45 AM#10
PharmD_Rodriguez said:
They are not contradictory, they measure different things, and this is the single most common misreading of a certificate.

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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