This Book is useful to M. Pharm students of all specializations those who are having Screening Methods, Clinical Research and Toxicology subject, M.Sc. Pharmacology and also for Ph. D scholars those who are doing Course studies and for scientists who work in laboratories while performing preclinical evaluation. This Book covers all steps of drug discovery like lead synthesis, preclinical studies, FDA requirements and clinical studies and also about High Throughput Screening. It also covers about all aspects about experimental animals. Breeding techniques, blood collection techniques, caring techniques and about production of various experimental useful animals. Various methods used in preclinical evaluations instead of animal models to minimize the usage of animals. It also contains Bioassays those are useful to estimate potential of sample by comparing with standard preparations. The book also covers various screening techniques of several drugs which are used to treat the CNS, CVS, ANS, Respiratory etc., system disorders. It also contains various principles of toxicology, mutagenicity, carcinogenicity, teratogenicity. Various types of poisons, general treatment of poisoning and special treatment of various poisonings.