Fig. 2.

Upper panel, comparison between jejunal P _eff,int calculated by: a M1 (cylindrical SA), b M2 (mSA according to Wilson’s method) and c M3 (mSA according to Helander and Fändriks’ method). Lower panel, prediction of ileal absorption clearance (permeability clearance) employing jejunal P _eff and ileal surface area using: d M1, e M2 and f M3. Solid light circles, BCS class 1; solid light squares, BCS class 2; solid dark upper triangles, BCS class 3; and solid dark lower triangles, BCS class 4. Black solid line represents the line of unity, whereas the dashed grey lines represent the twofold error