Red Blood Cell BindingPhysicochemistry and Binding
Binding to red blood cells affects the partitioning of the compound between blood and plasma and may lead to high blood to plasma ratio. If not taken into account, high blood to plasma ratio may result in incorrect calculation of the pharmacokinetic parameters as they are typically determined by analysis of compound concentrations in the plasma.
The degree of red blood cell binding is elucidated by incubating the study compound in fresh whole blood and plasma. The blood is centrifuged to plasma and the ratio of study compound observed in plasma in comparison to reference plasma sample will be used to calculate red blood cell binding and blood to plasma partitioning ratio. Also, a version with analysis of both plasma and red blood cell fractions is available.