Aim: To determine the inhibition potential of test compound for BCRP (Breast Cancer Resistance Protein Multidrug Transporter), an efflux transporter, using the Caco-2 cell model.

Background information: Caco-2 cells are a human colon adenocarcinoma cell line which express efflux transporters, such as P-gp (P-glycoprotein) and BCRP. Efflux transporters are involved in drug absorption and disposition. Inhibition of transporter-mediated efflux may affect the efficacy and safety of potential concomitant drugs in a clinical setting.

Inhibition transport assays are conducted both in the absorption (apical-to-basolateral) and efflux (basolateral-to-apical) directions. Probe substrate is added to either the apical or basolateral sides of the monolayer in the absence and presence of test compound. Probe substrate concentrations are quantified by UPLC-MS/MS using a calibration curve.