Toxicokinetics in the evaluation of toxicity data.

Toxicokinetics provides a powerful tool, which is not used sufficiently in the conduct and interpretation of animal toxicity studies. In selecting doses for toxicity studies toxicokinetic data can be used effectively. The tools of toxicokinetics are limited only by the toxicologists' understanding of basic biologic mechanisms. More knowledge on mechanisms of action implicates the possibility of more detailed toxicokinetic models. Physiologically based pharmacokinetic models are valuable in the interpretation of animal toxicity studies. They provide a physiological basis for extrapolating between species and routes of administration, and the future use of these models in setting acceptable levels of exposure for non-cancer toxicity in humans deserves serious consideration.