Dear All,
This is regarding the bioequivalence Q & A guidance posted by EMEA and FDA for the parent guidance on Bioavailability and Bioequivalence studies.
I am dealing with a Tablet formulation of a drug Paroxetine Hydrochloride.
Literature reports say that the drug shows non-linear kinetics due to saturable first pass effect at higher single doses and on multiple doses. Also, it is recommended to be given only with food, since the Cmax is higher with slightly early Tmax in fed state. However, the non-linearity is small and limited to the fast metabolisers. Also, the drug accumulates on multiple dosing.
As per the guidances, for non-linear drugs having more than proportional increase in AUC with increasing doses, a single dose study on HIGHEST DOSE will suffice. But if accumulation occurs, then a steady state study may be warranted. since it is to be given with food, a fed study may also be required.
Now, we have already done the study in a fasting state before the Q & A guidance was published. But we are about to make the submission now.
What kind of justifications etc could be given to justify the available study and are there any regulatory experience with anyone in the forum regarding the same?
Your comments on the requirements of the BE studies and the presented case are awaited.
thanks and regards
k.p.