The last decade or so has witnessed tremendous progress in methodology in the field of drug development in general and pharmacokinetics in particular. Clinical pharmacokinetics is using new tools for probing into the "black box" once being ac cessible only partly through experimental techniques and, mostly through mathemati cal and computer means. Development of computerized scanning, positron emission tomography (PET), stereoselectivity and other techniques are now enabling investi gators to have better pictures of the systems they are studying. Mathematical models through computer...