Bioequivalence and Bioavailability Forum

Hi Venu!

❝ Before conducting Pivotal study do you always require to conduct a pilot study of the same generic drug for calculation of intrasubject variability (of pilot study and then using this varibility for calculation of sample size for pivotal study).

No, because data from previous studies or from published data also suffice.
If you are using published data you should be cautious, because side conditions (sampling time points, hospitalization rules, posology, posture, analytical methods) may be quite different to the ones you will apply in your pivotal study.

❝ If the literature/pilot study is not available/conducted and a pivotal study is to be conducted then which/what intrasubject variability do you consider for those generic drugs.

I would consider it simply as ‘unknown’, which calls for a pilot study anyhow.
Remark: even if the CV is not given, you can calculate it from the confidence limits and the sample size of a published study by means of a little bit of algebra.