Formulation and evaluation of floating tablet of nimesulide by direct compression method

Nimesulide has been used versatile on fever, pain, inflammation, rheumatoid arthritis, tendinitis, thrombophlebitis and trauma. Common drawbacks of conventional tablet dosage forms of nimesulide show an irritant effect on the stomach due to its weakly acidic nature along it has short duration of action leading to poor bioavailability. A Floating drug delivery system for Nimesulide leads to overcoming the problem related to an irritant on the stomach by avoiding direct contact with the mucosa. Thus, this study was designed and performed to formulate and evaluate the floating tablet of Nimesulide and determine the release pattern of the prepared formulation. Tablets were prepared by direct compression method using different polymers (HPMC, carbopol, and guar gum), either in an individual or in combination. The formulation blend was subjected to various pre-formulation and post-formulation studies including floating lag time, total floating time, hardness, friability, drug content, weight uniformity, and in-vitro dissolution. According to pre- pre-formulation study, the flow property was found to be good to passable. Similarly, all post-compression parameters of floating tablets were found to be within acceptable limits except the friability test of F1 and F2 formulations. The tablet’s floating lag time was determined to be in the range of 7-153.5 seconds, and the total floating time was in the range of 4-7 hrs. From the data of dissolution, carbopol showed a slower release of drugs than that of HPMC and guar gum. The use of carbopol as a floating polymer showed release of drugs from dosage form was 84.46% in 7 hrs and 99.10% in 3 hrs with the use of HPMC, 96.39% in 4 hrs with the use of guar gum. A combination of HPMC and guar gum released drugs in a slow release of drugs only for 3 hrs i.e. 98.02% in 3 hrs, the combination of carbopol and HPMC slowly released drugs for 6 hrs i.e. 90.43% in 6 hrs, and the combination of carbopol and guar gum showed maximum slow release of drugs for greater than 7 hrs i.e.74.16% in 7hrs. Hence, among all the formulations, F7 with the combination of carbopol and guar gum as polymer showed a maximum slowed release effect for greater than 7 hrs, which can be taken as the best batch.