When can we do i.v. Study for-determining %F ?
As described under Q.7, if you are developing your drug only for oral route you do not have to characterize the absolute bioavailability (%F). However, if you are developing your drug for oral and IV routes you need to characterize the absolute bioavailability. The absolute bioavailability evaluation needs to be part of characterizing the basic pharmacokinetics of the drug including having it as one of your objectives in the radiolabel ADME study.
