A stability-indicating ultra perfomance liquid chromatography (UPLC) method was developed for the simultaneous determination of sumatriptan succinate and Naproxen sodium in pharmaceutical dosage forms. The chromatographic separation was achieved on C18, 50 mm × 4.8 mm, 1.8-µm particle size column. The mobile phase contains a mixture of 0.2% ortho phosphoric acid and acetonitrile as the mobile phase in gradient elution technique. The retention time of Sumatriptan and Naproxen was found to be 1.7 and 2.7 min respectively. The total runtime was 5 min within which two active compounds and degradation products were separated. This method allows the determination of 850-2565 µg mL -1 of sumatriptan succinate and 5000-15000 µg mL -1 of Naproxen sodium. The flow rate was 1.0 mL min -1 and the detection wavelength was 225 nm. The limit of detection (LOD) for sumatriptan succinate and Naproxen sodium was 1.9 and 1.5 µg mL -1 , respectively. The limit of quantification (LOQ) for sumatriptan succinate and Naproxen sodium was 6.3 and 4.8 µg mL -1 , respectively. This method was validated for accuracy, precision, linearity and robustness. sumatriptan succinate and Naproxen sodium were subjected to different ICH prescribed stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation and the method was also found to be stability indicating. Ultra performance liquid chromatography (UPLC) is a recent technique in liquid chromatography, which enables significant reductions in separation time and solvent consumption. Literature indicates that UPLC system allows about ninefold decrease in analysis time as compared to the conventional HPLC system using 5μm particle size analytical columns, and about threefold decrease in analysis time in comparison with 3μm particle size analytical columns without compromise on overall separation [23][24][25][26][27]. Rapid Simultaneous Determination of SumatriptanHence, a rapid, accurate stability indicating UPLC method for the simultaneous determination of SS and NS from combined dosage form was developed and validated. Experimental Instrumentation and chromatographic conditionsThe Waters UPLC Acquity system we used consists of a binary solvent manager, a sample manager and a UV detector. Zorbax SB C-18, 50 mm x 4.6 mm i.d with 1.8µm particles was used as stationary phase. 0.2% ortho phosphoric acid in water (pH 2.2) as solvent A and acetonitrile and water in the ratio 90:10; v/v, was as solvent B used for mobile phase. Prior to use, the mobile phase was mixed thoroughly and degassed. ReagentsStandards were supplied by D.C.O. Hyderabad, India. HPLC grade acetonitrile, analytical grade ortho phosphoric acids were purchased from Merck (Mumbai, India). Water was prepared by Millipore MilliQ Plus water purification system. Commercial pharmaceutical preparation of Triximet combined tablets were purchased from the market. The declared content of tablets was Sumatriptan 85 mg and Naproxen 500 mg per tablet. Preparation of solutionsStandard solutions: A standard so...