Fig. 5.

Relationship between human jejunal permeability (P_eff [34, 35]) and Caco-2 A-B apparent permeability (P_app [31]) at pH 7.4 measured using either pH 7.4 buffer (purple) or human plasma (green) as the transport medium. Solid lines represent the lines of best fit to the Log transformed data (for buffer: slope = 0.6989, y-int = − 0.3941; for plasma: slope = 0.7255, y-int = − 0.4239). The reported relationship from Sun et al. [45] is shown by the dashed black line (slope = 0.6836, y-int = − 0.5579)