PHARMACOKINETIC BASIS FOR INFLUENCE OF ROUTE OF ADMINISTRATION ON AREA UNDER PLASMA CONCENTRATION-TIME CURVE

A three‐compartment open system is proposed to explain the influence of route of administration (i.e., intravenous versus oral) on the area under the plasma concentration‐time curve. The hepatoportal system is treated as a compartment distinct from the vascular site being sampled. Computer analysis of the model using estimated pharmacokinetic parameters provided a successful prediction of the relative area under the plasma concentration‐time curves after oral and intravenous administration of aspirin in man. It is shown also that the proposed model yields a plasma concentration‐time curve after intravenous administration which may be described adequately by a biexponential equation under experimental conditions. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company