Reversed phase isocratic method has been developed for the quantitative analysis of local anesthetics drugs bupivacaine, ropivacaine and mepivacaine with very good separation for determination in bulk drug and dosage form of pharmaceutical. A Hypersil BDS C18 250×4.6mm,5µm column, mobile phase mix buffer and acetonitrile (34:66v/v) in 1000 ml and adjust pH 7.5 with diluted KOH solution, isocratic flow rate 0.9 mL/min and system detection is performed at 220 nm has been used for HPLC and LC-MS. Forced degradation study is perform in different stress condition such as by keeping it in sunlight, UV light, thermal, humidity, acidic, basic, and oxidative for extended time. Degradation products separation on HPLC chromatography. Degradation products separation on HPLC chromatography. Degradation study experiments are also analyzed on newly developed HPLC method.