Bioequivalence and Bioavailability Forum

Dear Phani!

❝ Are the terms ERROR VARIANCE, VARIABILITY, CV the same.

No. You get the error variance from ANOVA (mostly denoted as MSE - mean squares error). CV is calculated form MSE (see e.g. this post). Variability is a sloppy term (used for a manifold of things: variance, standard deviation, standard error, CV). You will not find it in statistical textbooks. If ever people should use it, only if the meaning is evident from the context.

❝ What factors contribute to the variability, the molecular or the formulation?

Please search the forum. A very similar question is still on the main page. CV depends not only the drug (essentially clearance) and formulation (F_a, potency), but also on ‘external’ variables (clinical performance, analytical method,…).

❝ How can it be estimated from the pilot study, if previous studies do not publish this.

❝ Is there any formula?

Hey, don’t you remember Mumbai (slides 11-16)?