Toxicokinetics

Abstract

Toxicokinetics is essentially the study of the kinetics, or movement, of a toxic chemical into and around the body as well as its fate within the body. Thus, there are four basic processes involved in toxicokinetics: absorption, distribution, metabolism, and excretion, all of which are characterized descriptively and mathematically in terms of rate and extent. Toxicokinetics represents an important part of the safety evaluation of chemicals, but because the subject is perceived as being mathematically based it tends to be regarded as difficult and rather unapproachable by biologists. This chapter relates the underlying physiological and biochemical processes to the basic pharmacokinetic parameters and constants. This is followed by a consideration of the types of experimental data that are needed in order to determine the various parameters. The chapter concludes with a consideration of specific aspects related to the interpretation of high‐dose, chronic animal studies.