Bioequivalence study of two favipiravir tablet formulations in healthy male subjects.

Objective The global pandemic called COVID-19 has dragged the world into a healthcare crisis, and favipiravir is one of the most prescribed agents against the virus so far. Favipiravir is a repurposed antiviral agent in treatment of SARS-CoV-2 infection, and to meet the current need, pharmaceutical companies are working for manufacturing licensed generic favipiravir. For getting the marketing authorization, the bioequivalence of the generic product must be proven first. The aim of this study is to demonstrate the bioequivalence of a new favipiravir tablet formulation as compared to the reference tablet formulation in healthy male subjects under fasting conditions. Materials and methods To prove the bioequivalence, a randomized, single oral dose, cross-over, two-period study was carried out in 30 healthy subjects under fasting conditions. Plasma favipiravir levels were quantified by using an in-house-developed high performance liquid chromatography with mass spectrometry detector (LC-MSD) method. Results The 90% CIs for the test/reference geometric mean ratios of the Cmax and AUC0-tlast were 88.02 - 103.11% and 98.19 - 102.06%, respectively. Conclusion This single-dose study has shown that the test and reference favipiravir products met the required bioequivalence criteria. Besides, both products were well tolerated and safe.