Bioequivalence and Bioavailability Forum

Dear Dipesh!

❝ 1. is it possible to estimate sample size for 2way crossover from parallel

❝ BE study????

No!
From a parallel study you only get information on the total variability (= between and within, or inter- and intra- subject); there is no way to extract the intra-subject CV from this kind of study.
One thing is granted: CV-intra < CV-total
For some drugs CV-total is >50%, but CV-intra <10%...

❝ 2. Assume that we have a data for 3way crossover(3 period - 6 sequence)

❝ pilot - BE study in which two test products(T1 and T2) were compared with

❝ RLD. Now we want to go ahead with either of the test formulation (i.e.

❝ either T1 or T2) to be compared with RLD in 2way crossover(2 period - 2

❝ sequence) pivotal study, then how to estimate the correct Sample Size for

❝ it???

It's quite reasonable to apply the CV-intra from the 3×6 study in sample size estimation for the pivotal 2×2.

❝ please suggest me way out or some reading on it????

S-C Chow and J-p Liu
Design and Analysis of Bioavailability and Bioequivalence Studies
Marcel Dekker, New York, 2nd Ed. (2000)

S Patterson and B Jones
Bioequivalence and Statistics in Clinical Pharmacology
Chapman & Hall, Boca Raton (2006)

D Hauschke, V Steinijans and I Pigeot
Bioequivalence Studies in Drug Development - Methods and Applications
John Wiley & Sons, Chichester (2007)