Bioequivalence and Bioavailability Forum

FDA “Draft Guidance on Budesonide” part 5, provides Recommendation Related to the Population Bioequivalence (PBE) Statistical Analysis Procedure (Step 3):

a. If SigmaR is greater than 0.1, the reference-scaled procedure should be used.
b. If SigmaR is less or equal to 0.1, then the constant-scaled procedure should be used.

However, when stage (m) is 1, SigmaR cannot be defined because the calculation for MSWk cannot proceed when m = 1 (see formula for MSWk in the guidance).



What approach should be used to calculate PBE when m = 1? Are there any alternative methods or approaches recommended in this scenario?

I have attached formula from Draft Guidance on Budesonide for reference.

Thanks for replying and suggesting!