This thesis is concerned with the analysis of certain drugs representing different classes of CNS and anti-diabetics agents including Esilicarpazepine , Pregabalin, Tramadol HCl , Saxagliptin hydrochloride and Dapagliflozin propanediol monohydrate. These drugs are widely prescribed; therefore it is significant to develop a simple, accurate, sensitive and applicable methods for their determination in pure form and in their pharmaceutical dosage forms. We utilized high-performance liquid chromatography as a powerful separation technique, spectrophotometry as a simple reagent-less separation-free technique, and voltammetry as a selective and efficient technique the determination of the cited drugs in different matrices.