power of bioequivalence test [Power / Sample Size]
❝ The BE test of the pharmacokinetic parameters (Cmax and AUC) should be powered to be 0.8.
I completely agree with d_labes and will add that power is not a formalised requirement. Consider it from a regulator's view; it is all about risks and benefit when she or he gives his nod to a dossier or shreds it. Given a dossier, the assessor has a study report with the actual results available. Power at this point will not affect neither the risk or the benefit, only the result of the trial counts here.
Power is your chance of showing equivalence with a given number of subjects provided your assumptions (around CV and T/R) are met. Therefore, power is not your headache and it is not the regulator's headache either. Power is a headache that belongs to the guy in the Armani suit who allocates money to your project. Such people often are not too well versed with science but they know how make a Windsor tie knot and other very useful stuff. Give such guy a graph of power versus N comes and present it as "chance of success as function of N" or even "chance of approval as function of cost" (in some cases give him an aspirin as well).
Pass or fail!