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.
The arithmetic in post #30 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.
Someone will know this better than I do and I hope they say so.
Door storage in a refrigerator is the warmest and most variable position in the appliance. A shelf at the back is a materially different environment.
I would want a second opinion before relying on that.
What I want from this published stability data actually covers thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.
Post #32 describes the usual case. This is about the unusual one.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
This is where my knowledge stops and I would rather mark the edge than blur it.
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.
The short answer was in the first line; everything after is the working.
Same experience here, different supplier, so it is at least not unique to one of them.
Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed.
Flagging that the sources on this are thinner than the confidence in the thread suggests.
Everything in post #41 holds. The case it does not cover is the one I have.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
Narrowing post #41, because the general version has more than one answer.
The most useful thing anyone has posted about published stability data actually covers in this category was a table of what had been measured and by whom. That is what I would want again.
Two claims get bundled together under published stability data actually covers and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.
Almost every disagreement in threads like this one dissolves once you say which of the two you are making.
Published stability data applies specifically to the formulation studied, under the specific conditions stated. It does not automatically transfer to something reconstituted at home in a different concentration with a different diluent. That caveat is not small.
The literature is thinner on this than the confidence in the thread implies.
The arithmetic in post #45 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.
The part I am sure of is shorter than the part I have written.
Worth separating two things that post #45 runs together.
I want to gently push back on the reply above about storage extrapolation. The advice is sound and the confidence is not.
We are extrapolating from stability data on a licensed formulation to a preparation that differs in concentration, diluent and container. That extrapolation is reasonable and it is still an extrapolation. Saying so does not weaken the practical recommendation; it just stops the recommendation from hardening into a fact that someone cites as certain.
This follows post #49 rather than contradicting it.
The useful distinction on published stability data actually covers is between what was measured and what was inferred from it. Both end up in the same sentence and only one of them has error bars.
I have three months of notes on published stability data actually covers 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.
Post #52 answers the question as asked. The question underneath it is different.
Published stability data covers a specific formulation at a specific concentration in a specific container. A home-reconstituted preparation matches none of those, and that caveat is the whole of the honest answer.
I read post #50 twice before replying, because I had assumed the opposite.
Second-hand on published stability data actually covers, so weight it accordingly — someone whose method I trust told me this and I have not verified it myself.
Where the published stability data actually covers discussion usually stalls is that nobody wants to say "I do not know" and everyone is willing to say "it varies". Those are the same sentence with different clothes on.
Post #55 and I disagree about the size of the effect, not about the direction.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
Narrowing post #56, because the general version has more than one answer.
My position on published stability data actually covers is current rather than settled. I have revised it once already and I expect to again, so treat it accordingly.
Adding the measurement that post #56 says would settle it.
A note on how published stability data actually covers gets discussed rather than on published stability data actually covers itself: the confident posts get the replies and the careful ones get ignored, and the careful ones have been right more often.
Helpful, and short, which on this subject is harder than long.