The present title “Pharmacokinetics” has been written for those in the pharmaceutical research and those responsible for the education and training in pharmaceutical science and technology of graduate and undergraduate students. Medicine is an ever changing science. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required. This branch of life science has progressed enormously in recent years and the significant advances in therapeutics and an understanding of the need to optimize during delivery in the body have brought about an increased awareness of the valuable role played by the dosage forms.