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c/coldchain·posted 1 months ago by u/adaeze_weiss

why does nobody talk about stability

Data

why does nobody talk about stability. I would rather ask a basic question now than get this wrong quietly for two months.

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.

Gel pack fully liquid on arrival, powder tested 98.1% against a claimed 97.5% afterwards. The pack had done its job for as long as it was designed to.

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.

Research-use-only material is not approved for human use and nothing here should be read as a recommendation to use it.

95 up / 31 down75% upvoted12 commentsid q3poau17 Jun 2026

12 comments

12 in this archive, depth 5

best — the order this archive was captured in

u/search_before_post19 points·1 months ago

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.

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u/bence_ibarra14 points·1 months ago

Push back: you cannot infer degradation from a temperature excursion alone. That is what testing is for.

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u/kian_solberg8 points·1 months ago

Correction: that stability figure covers the lyophilised powder, not the reconstituted solution. Different claim entirely.

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u/analog_alphabet7 points·1 months ago

ask what storage condition the stability statement was written against

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[deleted]5 points·1 months ago

[deleted]

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u/bastian_ekstrom4 points·1 months ago

How many days in transit, and which month?

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u/niels_norgaard11 points·1 months ago

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.

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u/coldchain_karenMOD7 points·1 months ago

Retitled: the original asserted degradation the post does not evidence.

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u/priya_weiss5 points·1 months ago

I would not freeze it in solution. That is a different failure mode and a worse one.

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u/elodie_kuipers3 points·1 months ago·edited

Lyophilisation removes the water that drives most degradation pathways. That is why the dry cake is comparatively robust and the reconstituted solution is not.

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u/zeynep_ndiaye2 points·1 months ago

if you want to know, log it, otherwise you are guessing

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u/prior_auth_painappeals1 point·1 months ago

Small fix — refrigerated, not frozen, once it is in solution.

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About c/coldchain

Temperature and stability in the real world: what an excursion actually costs you, why lyophilised powder is far more forgiving than reconstituted solution, how to read a logger CSV, and how to photograph a failed shipment so the conversation with the vendor is short.

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  1. Excursion claims need a logger trace or a photo taken at unboxing. "It felt warm" is not data.
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