An important feature of modern pharmaceutical analysis is the introduction of more refined and sensitive methods of physico-chemical analysis such as spectroscopy (colorimetry, spectrometry including UV, visible and IR regions, fluorimetry, nephlometry or turbidometry, NMR and Mass) and chromatography (GLC, HPLC and HPTLC) that enable us to ascertain the quality of drugs more accurately and with the smallest consumption of the analyte, reagents in less time. Reverse phase high performance liquid chromatography with ultra violet detection is the most accepted method of analysis by the pharmacopeias of the developed countries at present. UV-Visible spectrophotometry is one of the classical and widely used methods for the routine analysis of drugs. This book describes about new, simple, selective, sensitive and economical RP-HPLC and UV-Spectrophotometric methods for the quantification of drugs, such as pregabalin, azithromycin, sumatriptan succinate, imatinib mesylate, imatinib mesylate and ambroxol from bulk and pharmaceutical dosage forms. All these methods were validated as per ICH guidelines.