Mathematical basis and generalization of the Loo-Riegelman method for the determination of in vivo drug absorption.

A general numerical deconvolution method is derived for the determination of in vivo drug input functions. The derivation is based on linear interpolation of observed drug concentrations and deconvolution of the resulting trapezoidal function. Derived in vivo input functions are discontinuous. A general expression for the cumulative drug input is also derived. The latter expression is a generalization of the Loo-Riegelman equations. This deconvolution method give similar results to the "point-area" deconvolution method when deriving in vivo drug input functions.