Bioequivalence and Bioavailability Forum

Dear Auditor,

By aqueous stability I suppose that you mean stability in the stock and working solutions ? If this is the case I would indeed go for the peak area rather than area ratio. This is particularly important if a stable isotope labelled IS is being used: in such a case you can expect the analyte and the IS to have the same stability, or lack of stability: meaning that even if your signal decreases by 90 % the ratio will not be modified, and you will conclude that the analyte is stable...

Regarding recovery I would also consider separately the analyte and the internal standard, as you need information on the recovery of both when developing your method. The ratio brings little relevant information, if any.

Regards
Ohlbe