With its roots in the last century and currently exploiting the technology of today, the science of drug metabolism has made significant contributions to our understanding of chemico-biological interactions. This book reviews past successes and failures within the science and attempts to predict new directions. Each of the chapters of this book deals with an aspect of xenobiotic metabolism which has featured prominently in the development of the discipline. The volume is testimony to the breadth and depth of research into xenobiotic metabolism and covers the chemistry and enzymology of xenobiotic metabolism, enzyme modeling and structure activity relationships, pharmacokinetics, the use of recombinant gene technology, site directed mutagenesis, transgenic and gene knockout models, new analytical techniques including capillary electrophoresis-mass spectrometry, accelerator mass spectrometry, high throughput analysis toxicological assessment, pharmacogenetics, drug development and therapeutics. With new chemical entities constantly emerging and requiring evaluation, the concepts and techniques developed in this book will help focus future lines of investigation and help set priorities in the next millennium.