Encequidar (HM30181) mesylate monohydrate is a potent selective inhibitor of MDR1 (ABCB1, P-gp) with IC50 of 0.63 nM.
Encequidar (HM30181) effectively blocked transepithelial transport of paclitaxel in MDCK monolayers.
Encequidar (HM30181) does not inhibit MRP1 (ABCC1), MRP2 (ABCC2), and MRP3 (ABCC3), and partially inhibited BCRP (ABCG2) only at very high concentrations.
Oral co-administration of paclitaxel and HM30181 showed a tumor-inhibitory strength equal or superior to that of intravenous paclitaxel in the xenograft model in nude mice.
