Abstract
The communication presents the derivation and application of formulas for estimating the parameters MRT and VRT of the linear or linearised complex time invariant pharmacokinetic system, with or without shunt and time delays, defined on the animal body after any route of drug administration. the derivation is based on the model of the system transfer function and/or the model of the system weighting function. Thus the estimation of the system parameters MRT and VRT according to the formulas presented is not restricted only to using experimental data corresponding to the instantaneous system input. the approach provides feasibility of MRT and VRT estimation and may increase the accuracy of the estimates.