Is an insulated cool box good enough for storing reconstituted dulaglutide?

Setup, so nobody has to ask: an insulated cool box · dulaglutide.

This is a planning question. I know what my options are; I do not know how to weigh them.

What I want is the minimum viable version, which I suspect is smaller than what I would design.

How do I make this decision on evidence rather than on feel?

Answer first: dry, cold, dark and still, with the lot code where you can still read it in a year.

Lyophilised powder: refrigerated at two to eight degrees for months, frozen at minus twenty for longer. The gain from minus eighty over minus twenty is small for a dry solid and is not usually worth the arrangement.

Store with the desiccant sachet if one was supplied, inside the secondary container rather than loose in a drawer. Residual moisture is the dominant variable in solid-state stability.

Equilibrate before opening or you condense water into the cake.

The short version: powder in the freezer or fridge, reconstituted in the fridge for weeks, and never anything on a windowsill.

Keep vials in their original carton or in an opaque box. Light exposure matters for tryptophan-containing sequences and for anything with a chromophore, and a closed box is free.

Reconstituted with a preservative-containing diluent: refrigerated, conventionally treated as usable for about 28 days from first entry. Without a preservative, single use and discard.

Keep the desiccant with the vial and the certificate with the lot code.

edited 6 May 2025 by esben_lykke — added the citation requested in comments

The honest answer is that ordinary refrigeration handles almost every case people ask about.

Let a refrigerated or frozen vial equilibrate to room temperature before opening, so humid air does not condense water onto a cold cake.

Keep the certificate with the vial, physically or as a photograph filed under the lot code. A vial without a traceable certificate is an anonymous vial regardless of where it came from.

The 28-day in-use period for preservative-containing multi-dose preparations is printed on the diluent labelling and is a long-standing pharmacy convention.

Minus eighty buys very little over minus twenty for a dry solid.

Desiccant matters more than the last few degrees of cold for a lyophilised powder.

Label the vial at reconstitution with the date, the concentration and the resulting units per dose. This is the single most useful thirty seconds in the whole process.

Residual moisture is the dominant determinant of solid-state stability, which is why desiccants accompany lyophilised material.

Label the vial at reconstitution with date, concentration and units per dose.

Keep the paperwork with the material, or the material becomes anonymous.

Position matters less than people think: upright or on its side makes no difference to a lyophilised powder, and upright is marginally better for a reconstituted vial because it keeps the stopper dry.

Two-to-eight-degree refrigeration and minus-twenty freezing are the standard storage conditions for lyophilised peptides in supplier documentation across the market.

The caveat is that storage conditions preserve what you have and cannot improve it.

Dry, cold, dark, still. Four words and you have the answer.