Only the free unbound form of a drug is available in the body to exert its pharmacological effect, be biotransformed or be excreted. Thus binding of a compound to plasma or tissue proteins can potentially affect the pharmacokinetics, efficacy and toxicity of the drug.
Using the gold-standard equilibrium methodology and unique designed devices, i.e., HTDialysis and Rapid Equilibrium Dialysis (RED) , we provide a variety of protein binding assays.
PK parameters calculated from the plasma data may be misleading if differences exist between concentrations of the drug in the plasma and the red blood cells due to differential binding to a specific component in the blood. Therefore, measured blood-to-plasma (B/P) ratios may be helpful to conduct appropriate interpretation of PK results. Besides, B/P ratio can also be used to understand potential haemotoxicity.
The human colon carcinoma cell line caco-2, which exhibits a well-differentiated brush border on the apical surface and tight junctions, has been shown to acquire many of the features of absorptive intestinal cells when grown to a confluent monolayer. Thus it is widely employed as an in-vitro model to evaluate drug intestinal permeability. Besides, Caco-2 monolayers also functionally express various efflux transporters such as P-gp and BCRP and are therefore extensively used for studying efflux transporter-mediated transport.
Using the Corning HTS Transwell-24 System, we provide Caco-2 permeability services with different purposes: 1) to measure bi-directional apparent permeability coefficients (Papp) and efflux ratio (ER) of test compound, 2) to evaluate the potential of test compound as a P-gp/BCRP substrate, and 3) to evaluate the potential of the test compound as a P-gp inhibitor.
