Bioequivalence and Bioavailability Forum

Hi Sereng,

❝ What are the sample size “benefits” or “efficiencies” of undertaking this study as a replicate CO design (e.g., Test 50 x 2; Ref 50 x 2) versus a 2-way CO (Test 100 x 2; Ref 100 x 2). Any help would be much appreciated.

None. In both cases you risk a Refuse-to-Receive because you deviate from the guidance (recommending the 20 µg strength administered as a 60 µg dose). Theoretically you could deviate from the guidance if you have good reasons for doing so and initiate a Controlled Correspondence. However, I think your chance is close to nil because the guidance offers the option of biowaivers for the strengths 13, 25, 50, 75, 88, 100, 112, 125, 137, 150, and 175 µg. Only if you can’t perform a study with the 20 µg strength – because you don’t have in your line of strengths – you can give it a try.