Bioequivalence and Bioavailability Forum

Hi BE-proff,

as far as I know PowerTOST and other packages will generally be accepted.
Power is usually the sponsor's problem: It is the chance of showing BE when a set of assumptions are met. It usually does not affect patient's risk and so isn't where you get the most deficiency letters. At the end of the day, your assumptions are guess and guesses tend to have a lot of uncertainty, so power is in that perspective not a question of having a boatload of decimals right. Besides there is no regulatory power minimum or maximum though 80% or thereabouts is quite common.
Regulatory questions -or inspection triggers- may arise from bad guesses; for example it may be somewhat unethical to assume a CV of 8% and a GMR of 100.00% for most drugs (you'd be including too few patients for a realistic chance of showing BE). Thus, what the industry generally needs is a healthy dose of common sense rather than validation of power-calculating software to the 17th decimal. It is difficult to validate someone's ability to guess well anyhow.