In Vitro ADME

       The plasma protein binding assay determines the proportion of non-protein-bound (free) compounds in plasma through equilibrium dialysis. Since only compounds in the free state can bind to their targets to generate activity, compounds bound to plasma proteins may have longer half-lives and clearance rates. Therefore, the determination of plasma protein binding rate is an important reference for understanding the activity of compounds as well as tissue distribution.   

       In addition to plasma protein binding, protein binding assays also include liver microsomal binding and tissue binding.