Forced degradation studies: designing one that is informative — does this still hold? posts 31–42
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.
Collapsed as off-topic by two members at trust level 3 or above
Genuine question rather than a rhetorical one: has anyone here actually observed Forced degradation studies, as opposed to read about it? The thread is long and I cannot tell.
Building on post #30 rather than restating it.
Adding a reference point for Forced degradation studies. Mine is a single case, collected without controls, and I am posting the method alongside it so it can be discounted appropriately.
Reading back through, this was answered upthread and I missed it. My fault.
Transfer between laboratories: a method can be transferred from one lab to another, but the receiving lab needs to demonstrate that they can achieve the same performance. This requires comparative testing and sometimes small method refinements.
Why two laboratories may disagree: after validating the same method, they may still report different purity on the same sample due to integration differences, column age differences, subtle differences in mobile phase pH or temperature. This is normal and not a sign that one is wrong.
That is a description of practice, not a recommendation of it.
Where I part company with post #36, and it is a narrow parting.
I have no financial interest in anything named in this thread and I want to say so before I comment on Forced degradation studies, because it is the sort of subject where it matters.
System suitability is the ongoing evidence that a validated method is still performing. Validation is done once; suitability is done every run, and it is the one that appears on a certificate.
Post #37 put the caveat in the right place and I want to underline it.
Something worth flagging about Forced degradation studies: the strongest-sounding claims in this thread are the ones with no source attached, which is the usual pattern and not a coincidence.
I have three months of notes on Forced degradation studies and the honest summary is that the trend is real and the week-to-week numbers are noise. I nearly drew the opposite conclusion from the first fortnight.
This topic was referenced in
- What a stability-indicating method is and how you demonstrate oneAnalytics › Method validation · 4 replies
- Revisiting: Spike-and-recover accuracy for a peptide assayAnalytics › Method validation · 2 replies
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