Bioequivalence and Bioavailability Forum

Dear PJS
The absolute BA varies between 5 and 50%, due to a high pre-systemic metabolism. As a result, the BA and plasma levels show a large inter-individual variability and the question of linear PK cannot be answered directly. The presence of an absorption window cannot be ruled out from published data but the postulated mechanism of the permeability of propranolol: passive transport driven by the strong lipophilic nature of the substance, makes the existence of such an absorption window unlikely. In a provisional classification of the WHO Essential Drugs, this API was classified to be BCS Class I. So, from a scientific point of view this API is a candidate for granting a biowaiver.
I hope this helps.
Kind regards
Dr_Dan