I would be cautious about generalising from the published stability data actually covers example above. It is a good example. It is one example.
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Practice · Storage & stability · continued
Coming back to: What published stability data actually covers, and what it does not posts 121–149
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.
a.zamora, post #4: The arithmetic in post #3 is right; the assumption feeding it is the part to check. Published stability data actually covers: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this. Go to post
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
Genuinely open to being wrong about this one.
OTeixeira, post #44: 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. Go to post
Noted, and thank you for writing it out rather than summarising it.
r.nakamura, post #72: 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. Go to post
I had written a reply contradicting post #122 and deleted it. Here is what survived.
A definition problem is doing most of the work in this published stability data actually covers discussion. Once the term is pinned down I suspect the disagreement mostly goes away and what is left is small.
m.eriksen, post #88: Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed. If that reads as pedantic, it is, and it has saved me twice. Go to post
This follows post #124 rather than contradicting it.
Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed.
Norrington, post #116: Adding the measurement that post #115 says would settle it. Something worth flagging about published stability data actually covers: the strongest-sounding claims in this thread are the ones with no source attached, which is the usual pattern and not a coincidence. Go to post
What I would check first on published stability data actually covers is whether the thing being measured moved or whether the way of measuring it moved. Those look identical in a graph.
Filing a mild objection to the consensus on published stability data actually covers. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit.
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Taking post #128 at face value and following it one step further.
Published stability data actually covers was covered in the wiki last year and the page has a review date on it, which is a better starting point than my memory of a thread.
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peak_purity, post #89: 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. Go to post
A methods point on published stability data actually covers rather than a substantive one: if the comparison is not like for like, the difference you are measuring is the difference in method.
Collapsed as off-topic by two members at trust level 3 or above
Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed.
Everything in post #129 holds. The case it does not cover is the one I have.
If someone has run published stability data actually covers properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
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Narrowing post #133, because the general version has more than one answer.
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.
That holds under the stated conditions and I have stated them.
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j.petrov, post #106: Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed. Go to post
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 read post #133 twice before replying, because I had assumed the opposite.
Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear.
I looked this up rather than remembered it, which is the right order.
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Two people in this thread mean different things by published stability data actually covers and are disagreeing about the definition while believing they are disagreeing about the facts. Worth pausing to define it.
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Where I part company with post #137, and it is a narrow parting.
What I would want before treating published stability data actually covers as settled: the method, the sample, and whether anyone tried to find the opposite result. Two of the three are usually missing.
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Post #137 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.
That has been true for the cases I have seen and I have not seen many.
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r.oyelaran, post #119: Practical experience of published stability data actually covers, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable. Go to post
The number people quote for published stability data actually covers is a central estimate presented without its interval, and the interval is wide enough that the estimate is nearly uninformative on its own.
g.valckenaere, post #10: Acknowledging rather than arguing. The reasoning holds as far as I can follow it. Go to post
Post #140 put the caveat in the right place and I want to underline it.
Reading this published stability data actually covers thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.
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.
If the premise is wrong, everything after it is decoration.
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LJankowiak, post #137: I read post #133 twice before replying, because I had assumed the opposite. Clarity is a weak test. A solution can lose a significant fraction of its active content to degradation or adsorption while remaining perfectly clear. I looked this up rather than remembered it, which is the right order. Go to post
Post #142 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.
h.lindqvist, post #26: On published stability data actually covers I would separate what is worth knowing from what is worth acting on. The first list is long and the second is short, and conflating them is how threads get heated. Go to post
Where I part company with post #144, and it is a narrow parting.
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.
a.lindqvist, post #9: 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. This has been discussed before and I could not find the thread, so, again. Go to post
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.
This topic was closed 180 days after the last reply. Closing is automatic for quiet topics so that a settled answer does not collect new questions underneath it. If you have a follow-up, open a new topic and link back to this one — that keeps both readable and gives your question its own title.
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