Figure 4.

In vitro–in vivo correlation of efflux in multidrug resistance 1 transfected Madin-Darby canine kidney (MDCK-MDR1) cells and K_p,br/mu. K_p,br/mu is depicted as function of efflux derived from in vitro transporter experiments at 10 µM compound concentration in MDCK-MDR1 cells (MDCK_{Pgp_10_Efflux}). Regression analysis was performed with all data depicted in this plot. Solid line represents regression, blue area indicates the 2-fold error range, dashed lines are 3-fold error lines. Compounds from subgroup 1 (red circles) and subgroup 2 are highlighted because they were tested in additional in vitro transporter assays (see Figure 5; Figure 6 and corresponding text). Symbols represent average values (n = 2–3 for K_p,br/mu and n = 2 for in vitro efflux). Data are listed in Supplement Table S4.