Bioequivalence and Bioavailability Forum

Dear Srinivas,

❝ As per US FDA's guideline on Bio analytical method validation "Recovery experiments should be performed by comparing the analytical results for extracted samples at three concentrations (low, medium, and high) with unextracted standards that represent 100% recovery"

Which is actually incorrect: you should compare with samples spiked post-extraction, not with unextracted standards. Otherwise in LC-MS/MS methods what you will calculate is a mix of recovery and matrix effects, not just recovery.

❝ Now my doubt is if an additional QC (say MQC3(lower conc. than MQC2)) is introduced into the run, so that the subject samples meet at least two levels of QCs as per EMEA's guideline recommendation, is there a chance that the regulator may ask us to demonstrate the recovery at that additional QC level also?

I think not. There were even discussions at some bioanalytical conferences lately, where the FDA was present, that checking recovery at 2 levels of concentration (low and high) should be enough. The draft guidance asks you to check at 3 levels of concentration, not at each QC level.