Bioequivalence and Bioavailability Forum

Dear all,

FDA has prposed scaling approach in the OGDs of tacrolimus and warfarin.This will lead to narrower than 90-111.11% CI range for the drugs having intraCV less than 10.1%. Residual variability for AUC of warfarin has been reported to be 5.7%. Intrasub CV will be lesser than this. Hence AR will be much narrower. what could be the switchability issue between drug having GMR closer to 90% and other having GMR closer to 110%.what is practical evidence?
AR of 90-111.11% has been acceptable in some regulatories.what could be the consumer risk if the following approach has been followed?

1. AR-90-111.11% for the dugs having the Intracv equal to or less than 10.1%
   
2. AR- as per FDA scaling method for the intracv 10.1% to 21.42%
   
3. AR- 80-125% for intracv equal to or more than 21.42%

Regards,
pjs