Bioequivalence and Bioavailability Forum

Hi
According to the guideline evaluation of bioequivalence should be based upon measured concentrations of the parent compound. The reason for this is that Cmax of a parent compound is usually more sensitive to detect differences between formulations in absorption rate than Cmax of a metabolite. Also for inactive prodrugs, demonstration of bioequivalence for parent compound is recommended. The active metabolite does not need to be measured. The use of a metabolite as a surrogate for an active parent compound is not encouraged. I made the experience that the regulatory authorities asked for metobolite data but reluctantly accepted that I did not presented these data with reference to the guideline.
I hope this helps.
Kind regards
Dan