the data logger question that gets asked weekly, answered properly
the data logger question that gets asked weekly, answered properly — a position I have arrived at slowly and would like tested.
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.
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.
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.
If somebody has the same thing measured a different way, post it next to mine and we will see whether they agree.
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.
Small fix — refrigerated, not frozen, once it is in solution.
Push back: you cannot infer degradation from a temperature excursion alone. That is what testing is for.
That is the ambient temperature at the destination, not the temperature inside the box. The logger measures the second one.
if you want to know, log it, otherwise you are guessing
ask which lines are held in regional stock before you order in July
transit temperature is a distribution, not a number
transit temperature is a distribution, not a number
Adding the practical version: ask which lines are held regionally before you order in July.
Same. Door shelf is the worst place in the fridge and it is where everybody puts them.
Left up and added to the lane table. Origin, destination and month were all included, which is all we ask.
ask what storage condition the stability statement was written against
ask what storage condition the stability statement was written against
Agreed, and a logger costs less than the vial you are worrying about.
This. A liquid gel pack on arrival tells you about the pack’s duty cycle, not about the vial.
Wrote the reconstitution date on the vial for the first time last year. Have never once since wondered how old a solution is.
Where in the fridge is it sitting now?
the door shelf is the worst place in the fridge
Powder or already in solution?
A stability statement is only meaningful with its conditions attached: temperature, duration, light exposure, and whether it covers powder or solution. Ask which.
A stability statement is only meaningful with its conditions attached: temperature, duration, light exposure, and whether it covers powder or solution
This is the distinction that resolves most threads here — powder and solution are different problems.
Kept a vial at room temperature for eleven days by accident. Tested it out of guilt. It was fine.
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.
Correction: that stability figure covers the lyophilised powder, not the reconstituted solution. Different claim entirely.
Moved everything off the fridge door after reading a thread here and my temperature log immediately got boring.
lyophilised powder is far more forgiving than the panic threads suggest
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.
Gel pack fully liquid on arrival, powder tested 98.4% against a claimed 98.0% afterwards. The pack had done its job for as long as it was designed to.
Lyophilisation removes the water that drives most degradation pathways. That is why the dry cake is comparatively robust and the reconstituted solution is not.
Asked SSA which lines they hold regionally and got a straight list back. That answered my summer ordering question completely.
light matters more than people think for some of these
- 1Once in solution, the relevant risks are hydrolysis, aggregation and, for…8 comments in this branch · started by u/anya_rautio
- 2Same. Door shelf is the worst place in the fridge and it is where everybody…8 comments in this branch · started by u/nikhil_asante