Bioequivalence and Bioavailability Forum

❝ […] In the 2×2 the ISCV is actually derived from a common variance of the treatment ones. If treat­ment vari­ances are substantially different (e.g., high for a ‘bad’ reference and low for a ‘good’ test), the residual error – and therefore the CI – will be inflated. That’s why we need high sample sizes for 2×2 Xovers of HVDPs – the test will be punished for the reference’s CV. In (fully) replicated design together with RSABE in this case you will get a reward in terms of sample size. But that’s somehow OT.

Very interesting. I am wondering if an estimated CVintra from a 2×2 study (test two different formulation) is still a good estimate when the Cmax or AUC difference between the two formulations are <30%, assumming this 30% is not substantially different?

Thanks
zan

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Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Helmut]