All drugs display their efficacy and toxicity by binding to intended and non-intended targets with various levels of occupancy and duration. The ability to accurately determine kinetic rate constants enables compound differentiation otherwise indistinguishable by binding affinity. Moreover, for in vivo experiments with inconclusive PK–PD relationships, knowledge of drug residence time on the target of interest may be extremely helpful to explain observed data. Several methods have been developed to determine kinetic on- and off-rates for small molecules…