This book show a good practical examples of application of Sodium-1,2-Naphthoquinone-4- Sulfonate (NQS) in analysis of pharmaceutical amines by spectrophotometer. In this book the optimization, validation, and application of spectrophotometry for determination of three cardiovascular drugs, namely: Atenolol (ATE), Doxazosin mesylate (DOX) and Lisinopril dihydrate (LID); and one antipsychotic drug, namely: Olanzapine (OLP) in pharmaceutical formulations are described