A linear recirculation model for drug disposition.

A new approach to the modeling of drug disposition is described. Disposition is regarded as the result of repetitive passes of the drug around the circulation. Mathematical analysis of experimental blood concentration data yields an expression describing the kinetics of a single pass through the tissues. In physicochemical terms the single-pass behavior depends to a large extent on the interaction of the drug with individual tissues, which greatly simplifies interpretation. The method may reveal features of disposition not apparent from experimental blood concentration data.