Coming back to: What published stability data actually covers, and what it does not posts 61–90
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.
Post #59 is the version of this I will quote in future. One addition.
Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed.
I had written a reply contradicting post #63 and deleted it. Here is what survived.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
That is clearer than the version I had in my head. Thank you.
Published stability data actually covers looks different depending on whether you are reading the primary literature or the summaries of it, and the difference is not in our favour.
Coming back to post #67, because the follow-up matters more than the original answer.
Adding a small correction to the published stability data actually covers summary above rather than a disagreement with it. The substance holds; one of the figures is out by a factor that matters.
Published stability data actually covers is a good example of a question where the honest answer is boring and the interesting answers are unsupported. I would go with boring.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
The claim is narrower than it sounds, and deliberately so.
Room-temperature stability claims for licensed products in this class are specific about duration and about whether the period is cumulative. Cumulative is the word that gets dropped in summaries.
Adding it because I spent an afternoon working it out and nobody should have to twice.
Confirming post #70 from a second method, which matters more than confirming it from a second person.
Reframing published stability data actually covers slightly, because I think the disagreement is about the question rather than the answer. If the question is "does it happen", yes. If it is "how often", nobody here knows.
A supplier stability statement tied to a named storage condition can be evaluated. One that says "store cool" cannot, and the difference between those two documents is larger than it looks.
I would not lead a decision with this, but I would not ignore it either.
Post #72 describes the usual case. This is about the unusual one.
My understanding of published stability data actually covers is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it.
This is the sort of exchange that makes the archive worth searching.
The arithmetic in post #78 is right; the assumption feeding it is the part to check.
Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed.
Room-temperature stability claims for licensed products in this class are specific about duration and about whether the period is cumulative. Cumulative is the word that gets dropped in summaries.
If it helps: the failure mode here is usually boring rather than dramatic.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
It is the sort of thing that seems obvious in retrospect and was not at the time.
Building on post #85 rather than restating it.
Published stability data actually covers: I have looked for the primary source twice and failed twice. Either it does not exist or it is somewhere I do not know to look, and I would like to know which.
Everything in post #85 holds. The case it does not cover is the one I have.
The practical version of published stability data actually covers is three sentences long. The rigorous version is three pages and reaches the same conclusion with the conditions attached.
Post #85 and I disagree about the size of the effect, not about the direction.
Published stability data actually covers sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly.
Taking post #89 at face value and following it one step further.
Trying to state the published stability data actually covers position in a way that someone who disagrees would recognise as fair, because I do not think the version in this thread passes that test.