This book is an outcome of years of teaching to the undergraduate students and sincerely began with classroom handouts highlighting important concept, equation and their use. I have tried not to burden the text with too many mathematical details and unnecessary elaboration. However, where applicable, I have tried to explain the step-wise derivation of the final mathematical formula for the easy understanding which will be enough for undergraduate students. In addition, this book has adequate numerical practice along with multiple choices questions with solutions which will definitely help students who is looking for complete solutions as well. Brain Teaser questions collection in the book are for those wanting to understand concept of bio pharmaceutics and pharmaceutics in more pragmatic style. Simple Illustrations are also drawn to simplify mechanism of drug absorption, distribution, metabolism and other bio pharmaceutical aspects. I believe readers will find this book valuable. I am indebted to my mentors, parents, families, friends, seniors, juniors, and a number of former and current diligent and serious students without whom this book would never have been complete.