<b>Analytical Methods Development and Validation of Naproxen and Sumatriptan by RP HPLC</b> Aim and objective A simple, précised, accurate method was developed for the estimation of Crizotinib by RP HPLC technique. Chromatographic conditions used are stationary phase BDS 250x4.6 mm, 5µ. Mobile phase buffer Methodology Acetonitrile in the ratio of 60 40 and flow rate was maintained at1ml min, detection wave length was 267 nm, column temperature was set to 30o C and diluents was methanol water System suitability parameters were studied by injecting the standard five times and results were well 50 50 , Results and Discussion Conditions were finalized as optimized method under acceptance criteria. Linearity study was carried out between 25 to 150 levels, r2 value was found to be as 0.999. Precision was found to be 1.26 for repeatability and 0.93 for intermediate precision. LOD and LOQ are 0.080 ug ml. By using above method assay of marketed formulation was carried out 100.24 was present. Crizotinib, HPLC, ICH Guidelines, Method development 325-327 Issue-4 Volume-3 Prapulla Putta