the lyophilised question that gets asked weekly, answered properly
the lyophilised question that gets asked weekly, answered properly, and I am aware this is a minority view on this board.
Gel packs are designed for a duty cycle. A liquid pack at the end of a longer-than-expected transit is a pack behaving as specified, not evidence of an excursion in the vial.
A transit temperature logger records a distribution, and time above a threshold matters as much as peak temperature. That is the argument for logging rather than guessing.
Regional stock changes the question rather than answering it: shorter lanes mean less exposure and fewer variables, which is why the warehouse question is worth asking before ordering in summer.
If two or three other people have done the same thing we might actually learn something. Alone it is an anecdote.
best — the order this archive was captured in
Once in solution, the relevant risks are hydrolysis, aggregation and, for some sequences, oxidation. Refrigeration slows all three; freezing a solution introduces a separate risk at the ice interface.
Once in solution, the relevant risks are hydrolysis, aggregation and, for some sequences, oxidation.
Disagreeing with this line only: freezing a reconstituted vial is not a safe default.
Push back: you cannot infer degradation from a temperature excursion alone. That is what testing is for.
Yes — a logger in the box turns a fortnight of speculation into a chart.
Wrote the reconstitution date on the vial for the first time last year. Have never once since wondered how old a solution is.
Careful. "The cold chain failed" is a strong claim and the evidence you have is a warm box.
Not convinced. A warm pack on day six is expected behaviour from a pack designed for four.
Correction: that stability figure covers the lyophilised powder, not the reconstituted solution. Different claim entirely.
Not convinced.
Adding the practical version: ask which lines are held regionally before you order in July.
the door shelf is the worst place in the fridge
You cannot infer potency from a temperature record. The record tells you what happened to the box; only a test tells you what happened to the material.
You cannot infer potency from a temperature record.
This is the distinction that resolves most threads here — powder and solution are different problems.
This is the distinction that resolves most threads here — powder and solution are different problems.
Agreed, and a logger costs less than the vial you are worrying about.
powder at room temperature for a few days is usually a non-event
Is this a line they hold in regional stock or is it shipping from origin?
Kept a vial at room temperature for eleven days by accident. Tested it out of guilt. It was fine.
the excursion that matters is the one after reconstitution
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