Impurity profiling and drug degradation pathways are essentials features for regulatory acceptance of any new drug entity. Despite of technological advancements in pharmaceutical analysis, structural elucidation of drug molecules, impurities produced during formulation remains challenging tasks for researchers. Unique chemical behavior, complex properties and interactions of different functional groups involved in active pharmaceutical ingredients along with different chemical environments with excipients and storage condition further complicate the issues. Furthermore isolation and characterization of impurities with special references to toxic metabolites is essential for acceptance of new drug molecules by regulatory agencies. Recently discovered and patented nitrate esters of paracetamol having improved analgesic and anti-inflammatory activities then parent drug and less hepatotoxicity in overdose is selected as model drug entity. This book is an attempt to provide experimental insights into the chemical, analytical and establishment of drug degradation pathways in forced conditions in lucid manner for easy understanding to meet future expectations of scientific fraternities.