Bioequivalence and Bioavailability Forum

Hi everyone,

I was doing some RSABE refreshments (yeah getting old) and noticed a disparity between sample size generated by PowerTost & Endrenyi vs a paper from B. Davit et al.

Davit et al published a table showing the sample sizes for a 4-way replicate study design for a series of intrasubject CVs with GMR set at 1.0 and power=80%.

CV      Davit    PowerTost
30%      18      15
45%      34      16
60%      56      17
75%      80      19

I didn't tabulate results from Endrenyi's paper since the numbers are similar to the ones from PowerTOST. I can't confirm how Davit et al's paper arrived with their numbers since the article didn't mention the origin of those values.

The paper is:

B. Davit et al. Implementation of a Reference-Scaled Average Bioequivalence Approach for Highly Variable Generic Drug Products by the US Food and Drug Administration. The AAPS Journal, Vol. 14, No. 4, December 2012

Thanks

John