Analytical methods development and validation play important roles in the discovery, development, and manufacture of pharmaceuticals. The current good manufacturing practice (cGMP) and Food Drug Administration (FDA) Guidelines insist for adoption of sound methods of analysis with greater sensitivity and reproducibility. This thesis describes analytical methods developed for drug determination in pharmaceutical dosage forms and biological matrixes including Chromatography (RP-HPLC) and Hyphenated Techniques (LC-MS/MS). Methods have been developed for separation and quantification of selected drugs from categories like Antihypertensive, Antihyperlipidemic, Skeletal Muscle Relaxant, Non-Steroidal Anti-inflammatory Drug (NSAID), Antibiotic, Anticonvulsant, Antiviral, and Analeptic.