Importance of assay specificity for plasma protein binding determinations

Plasma or serum protein binding determinations of extensively bound drugs are subject to serious error if the analytical methods employed do not discriminate between such drugs and their degradation products, metabolites, and impurities. Experimental evidence is presented to demonstrate the magnitude of this problem with respect to warfarin.Supported in part by Grant GM20852 from the National Institutes of Health.This is paper XVI in the series Comparative pharmacokinetics of coumarin anticoagulants. Previous paper: A. Yacobi, C.-M. Lai, and G. Levy,J. Pharm. Sci.64 (1975).