[Discussion] can we stop arguing about ice pack until somebody posts a number
can we stop arguing about ice pack until somebody posts a number. Searched first, found three threads that contradict each other, hence the post.
Put a logger in three consecutive orders. Two never went above the range at all and the third spent four hours warm on a Friday. Cost me almost nothing to stop wondering.
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
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.
Lyophilisation removes the water that drives most degradation pathways. That is why the dry cake is comparatively robust and the reconstituted solution is not.
regional stock removes most of this problem entirely
Is this a line they hold in regional stock or is it shipping from origin?
if you want to know, log it, otherwise you are guessing
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.
I would not freeze it in solution. That is a different failure mode and a worse one.
A stability statement is only meaningful with its conditions attached: temperature, duration, light exposure, and whether it covers powder or solution. Ask which.
ask which lines are held in regional stock before you order in July
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.
lyophilised powder is far more forgiving than the panic threads suggest
Left up and added to the lane table. Origin, destination and month were all included, which is all we ask.
lyophilised powder is far more forgiving than the panic threads suggest
bence_ibarra is right that the pack failing is not the material failing. Two separate claims.
Push back: you cannot infer degradation from a temperature excursion alone. That is what testing is for.
ask what storage condition the stability statement was written against
Gel pack fully liquid on arrival, powder tested 98.6% against a claimed 98.5% afterwards. The pack had done its job for as long as it was designed to.
Not convinced. A warm pack on day six is expected behaviour from a pack designed for four.
That is a lane problem rather than a packaging problem, and the fixes are different.
a warm gel pack tells you the pack failed, not that the material did
a warm gel pack tells you the pack failed, not that the material did
This is the distinction that resolves most threads here — powder and solution are different problems.