Drug discovery refers to the process of finding potential new therapeutic entities by using a combination of translational, computational, experimental and clinical models. The process of developing new drugs based on an understanding of a biological target is known as drug design. It entails designing molecules with shapes and charge which is complementary to the molecular target with which they bind and interact. Preclinical research using animal and cell-based models, clinical trials on humans, and obtaining regulatory approval to market the drugs are the key steps involved in the development and discovery of new drugs. Modern drug discovery encompasses the identification of screening hits, medicinal chemistry and optimization of those screening hits to improve their selectivity, metabolic stability, affinity, oral bioavailability and efficacy. This book explores all the new frontiers in drug design and discovery. It covers in detail some existent theories and innovative concepts revolving around this domain. The extensive content of this book provides the readers with a thorough understanding of the subject.