Bioequivalence and Bioavailability Forum

Dear Erol,

❝ What should be the freezer storage intervals for plasma to be stored at -20°C. Our freezer's range is between -15°C and -40°C. We have a question for this. Question is upper limit is high and it must be maximum -25°C.

I guess you mean the lower limit, giving a range of -25°C to -15°C ?

❝ Is anyone can give me information for the stability of plasma samples -40°C is wrong and why?

Generally speaking, if your analyte is stable at -20°C it will be also stable at -40°C. The EMA guideline allows a bracketing approach for small molecules (i.e. if you demonstrate stability at -70°C and -20°C it will cover all temperatures in between). The FDA 2018 guidance goes farther and states that stability at -20°C would cover colder temperatures. The draft M10 guideline allows extrapolation to lower temperatures only for small molecules but allows bracketing for large molecules. This still remains from the Crystal City 3 discussions and White Paper (hey, this one used to be free and now seems to be only accessible for a fee ?). I've heard since at a number of bioanalytical conferences that there is no published data to back up this distinction between small and large molecules. My understanding from discussions at the 13^th WRIB last week is that industry will try and have it removed from the M10 final guidance.

Oh, by the way: I doubt your -20°C freezer would be able to reach -40°C anyway.