Development and in-vitro Evaluation of Once Daily Tablet Dosage Form of Loxoprofen Sodium

Purpose: To formulate and characterize once daily controlled release tablet of loxoprofen sodium. Methods: Eudragit RS-100, hydroxylpropyl methylcellulose (HPMC) and pectin were used as release retarding polymers. All the formulations were prepared by direct compression method. Various pre-compression studies were carried out to determine Hausner's ratio, Carr's index, angle of repose, bulk density and tapped density Differential scanning calorimetry (DSC) studies and also post-compression studies to evaluate hardness, friability, weight variation, drug content, in-vitro drug release were conducted on the tablets. The drug release data were subjected to kinetic models, including zero order, first order, Hixon Crowell, Higuchi and Korsmeyer-Peppas. Results: Compressibility index (7.6 +/- 1.32 - 12.5 +/- 1.43%), Hausner's ratio (1.08 +/- 0.04 - 1.14 +/- 0.03), angle of repose (27.78 +/- 0.47 - 30.49 +/- 0.46 degrees), hardness (6.25 +/- 0.27 - 7.21 +/- 0.21 kg/cm(2)), friability (0.14 +/- 0.06 - 0.28 +/- 0.0 %), weight variation (249.5 +/- 2.09 - 251.35 +/- 2.41 mg) and drug content (97.30 +/- 0.28 - 103.70 +/- 0.31 %) were within generally accepted limits for the pre- and post-compression formulations, respectively. The tablets having the maximum amount of among the three polymers tested as matrix materials, HPMC, represented by F3 tablets, exerted better sustained release properties after 12 h. Release pattern was more of Fickian diffusion followed by Higuchi mechanism. Conclusion: The release of the loxoprofen sodium was optimized up to 12 h.