Bioequivalence and Bioavailability Forum

Dear bjkim97

First, I understand your English and English is not my mother language, don't worry.

I used to be a rookie in this business and your problem was my problem and I'm sure this was everyone problem.

I think your problem is not sample size calculation because your calculated sample size from initial parameters is correct but the problem might be CV selection.

You give 2 papers and I also have a few pantoprazole BE papers but I cannot access full text your first one and its abstract did not give number of subjects in the study, so the intra-subject CV of the first one could not be accessed by only the information from its abstract. However, the rest literature (that I have) indicated this drug is not high CV drug, it's around 11-18% but it seem to be higher in fed condition and also in MR. If I were you I will set 20% CV into the sample size calculation and find more information for fed condition or MR.

The intra-subject CV is a random variable, so it can be any value around its mean with its variance in each condition. It's not surprising if CV from any study are difference because the condition is not same at least time condition.

IMHO, CV selection depend on you and your sponsor, you should explain them and then cooperate with them to decide with full any support and select the optimum CV that make you and your sponsor feel safe under the budget limitation.

Boonchai L.