A new rapid, simple and reproducible UV spectrophotometric method was developed and validated for the estimation of Naproxen Sodium (NpSd) in bulk and pharmaceutical formulation. The quantification of NpSd was done at 230 nm in methanol and in buffer of pH 6.8 and 9. Beer’s law was obeyed in the concentration range of 4 - 36 (r2 = 0.999) in methanol and 5 - 25 μgmL﹣1 in buffer of pH 6.8 and 9 (r2 = 0.988 and 0.997) respectively. The apparent molar absorptivity values were also calculated in all mediums. All parameters according to ICH guideline were tested and validated. The detection and quantitation limits were found to be 0.054, 0.083, 0.073 and 0.181, 0.251, 0.211 μgmL﹣1 respectively. These methods were applied directly to the analysis of the pharmaceutical tablet preparations (Anex? tablet 250 mg). The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation < 3%), while being simple, cheap and less time consuming and hence can be suitably applied for the estimation of NpSd in dosage forms and dissolution studies.
 S. Mohideen, M. Shivakanth, P. SureshKumar, S. N. Krishnan, Y. Surendranath and T. Satyanarayana, “Development and Validation of Analytical Method for Naproxen and Pantoprazole in Capsule Dosage Form,” Der Pharmacia Sinica, Vol. 2, No. 6, 2011, pp. 114-121.
 G. Kanoute, E. Nivaud, B. Paulet and P. Boucly, “Dosage de Derives de l’acide Phenylpropionique: A Activite Pharmacologique par Titrage Coulometrique,” Talanta, Vol. 31, No. 2, 1984, pp. 144-146.
 M. S. Mahrous, M. M. Abdel-Khalek and M. E. Abdel-Hamid, “Quantitation of Indomethacin, Naproxen, and Ibuprofen in Pharmaceutical Dosage Forms by First and Second Derivative Ultraviolet Spectrometry,” Journal-Association of Official Analytical Chemists, Vol. 68, No. 3, 1985, pp. 535-539.
 S. Kulsum, M. Padmalatha, K. Sandeep, B. Saptasila and G. Vidyasagar, “Spectrophotometric Methods for the Determination of Naproxen Sodium in Pure and Pharmaceutical Dosage Forms,” International Journal of Biomedical and Pharmaceutical Sciences, Vol. 2, 2011, pp. 1303-1307.
 R. P. Gondalia and A. P. Dharamsi, “Spectrophotometric Simultaneous Estimation of Naproxen Sodium and Sumatriptan Succinate in Tablet Dosage Forms,” International Journal of Biomedical and Pharmaceutical Sciences, Vol. 1, 2011, pp. 24-26.
 T. Haque, M. M. U. Talukder, S. Laila, K. Fatema and A. K. L. Kabir, “Simultaneous Estimation of Naproxen and Ranitidine HCl by Using UV Spectrophotometer,” Stamford Journal of Pharmaceutical Sciences, Vol. 1, 2008, pp. 18-24.
 A. Segura Carretero, C. Cruces-Blanco, M. I. Ramirez Garcia, B. Canabate Diaz and A. Fernandez Gutierrez, “Simple and Rapid Determination of the Drug Naproxen in Pharmaceutical Preparations by Heavy Atom-Induced Room Temperature Phosphorescence,” Talanta, Vol. 50, No. 2, 1999, pp. 401-407.
 P. Venkatarao, M. N. Kumar and M. R. Kumar, “Novel Validated Stability-Indicating UPLC Method for the Estimation of Naproxen and Its Impurities in Bulk Drugs and Pharmaceutical Dosage Form,” Scientia Pharmaceutica, Vol. 80, 2012, pp. 965-976.
 I. W. Wainer and T. D. Doyle, “Application of High-Performance Liquid Chromatographic Chiral Stationary Phases to Pharmaceutical Analysis Structural and Conformational Effects in the Direct Enantiomeric Resolution of α-Methylarylacetic Acid Antiinflammatory Agents,” Journal of Chromatography A, Vol. 284, 1984, pp. 117-124.
 R. Kumar, P. Singh and H. Singh, “Development and Validation of Rp-hplc Method for Simultaneous Estimation of Naproxen and Pantoprazole in Pharmaceutical Dosage Form,” International Journal of Pharma Research and Development, Vol. 2, 2011, p. 6.
 Y. H. Hsu, Y. B. Liou, J. A. Lee, C. Y. Chen and A. B. Wu, “Assay of Naproxen by High Performance Liquid Chromatography and Identification of Its Photo-products by LC-ESI MS,” Biomedical Chromatography, Vol. 20, No. 8, 2006, pp. 787-793.
 L. Monser and F. Darghouth, “Simultaneous Determination of Naproxen and Related Compounds by HPLC Using Porous Graphitic Carbon Column,” Journal of Pharmaceutical and Biomedical Analysis, Vol. 32, No. 4-5, 2003, pp. 1087-1092.
 W. R. G. Baeyens, G. Van der Weken and M. Schelkens, “Diclofenac and Naproxen Analysis by Microbore Liquid Chromatography (LC) with Native Fluorescence Detection,” Journal of Fluorescence, Vol. 5, No. 2, 1995, pp. 131-134.