Bioequivalence and Bioavailability Forum

Dear Max
There is no cut-off half life limit to select a parallel design. In your case proceed with a two way crossover design. A maximum half life of 44 h would lead to a wash out of 14 days (or even less since this is more than 7 times thalf). A wash out period of 14 days is very common in standard bioequivalence studies. Per protocol, your study design is two way crossover and sample size is 46. If you can not recruit 46 subjects at once you have to conducted the study in cohorts and you do not necessarily need to prepare a protocol amendment. If your study conduct is standardised and the conditions are the same for both (all) subject groups then this will not affect study outcome adversely since the intra-subject (!) variabilty should not increase.
I hope this helps
Kind regards
Dr_Dan