Bioequivalence and Bioavailability Forum

Dear LKN & MGR!

❝ ❝ If the Cv is 62% isn't it possible to have the wider acceptance range for equivalence as in HVD 0.7-1.33 [...]

Oops! Just a reminder:
Regulators commonly define an acceptable deviation from the reference of 20%. In the old days (no log-transformation of data) this meant an acceptance range of 80%-120%. When the log-transformation came into play in the mid '80ies - in order to keep the symetry around 100% - by convention (!) the lower limit in the untransformed scale was set to 100%-20% = 80% and the upper limit to its reciprocal 1/80% = 125%. In log-scale -0.2231 | +0.2231 (symetrical around zero). There was some debate whether the limits should be set to 100%+20% = 120% and 1/120% = 83.3...% (log-scale -0.1823 | -0.1823), but people advocating this approach lost - maybe just by chance...

Therefore there are no limits like 0.7-1.33!

In a very old European BE-draft (again from the '80ies) 70%-142.85714% (=1/0.7) were mentioned; currently 75%-133.33% are given as an example and sametimes a narrower range of 90%-111.11% for NTIDs.