Bioequivalence and Bioavailability Forum

Dear Sir, I read a protocol for a Be study for an extended - release formulation.
It was a single dose study(only in fasted conditions) and multi- dose study. In this study, the first period of the single dose study was followed by the first period of the steady – state study. The wash out period began after the last dose administered in the steady - state study. The second period was identical with the first one. Is correct this design for the study?
I know that for extended - release formulations must be performed totally different studies (single dose and multi - dose studies) in different periods. Is this correct?
Thank you.