2,3,7,8-tetrachlorodibenzo-p-dioxin elimination in the rat: first order or zero order?

Summary Data on the elimination of 2,3,7,8-tetrachlorodibenzo- p -dioxin from the rat were analysed for the best fit to a zero- or a first-order kinetic process. The limited data available made it impossible to distinguish the order of the process, and therefore previously reported values for the half-life of this compound may be invalid. The nature of the mathematics used and the importance of the kinetic order in evaluating the disposition of xenobiotics are discussed.