This book deals with the Pharmacokinetic evaluation of Sitagliptin, which is an oral DPP-4 inhibitor for the treatment of Type 2 Diabetes. This book provides the information about bio-analytical method development and validation of drugs by high performance liquid chromatography. The developed method for Sitagliptin in this book might be applicable to bioavailability and bioequivalence studies. Users of this book will be provided the simple, sensitive and validated bio-analytical method for the estimation of Sitagliptin in plasma and its applications to the pharmacokinetic studies.