Studies In Formulation Of Orodispersible Tablets Of Rofecoxib
Orodispersible tablets are better choice for the pediatric and geriatric patients. Present study demonstrates the use of factorial design in the formulation of orodispersible tablets of rofecoxib. Preliminary screening of three superdisintegrants namely sodium starch glycolate, crospovidone and croscarmellose sodium was carried out (batches AA1 to AA9) and crospovidone was found most effective giving lowest disintegration time and wetting time. Batches AA10 to AA12 were prepared to optimize the amount of crospovidone and the optimum concentration of crospovidone was found to be around 10%. Mannitol was incorporated as a diluent to improve palatability and to impart sweet taste as well as to keep the tablet weight (100 mg) constant in all the batches. From the preliminary results, a 32full factorial design was employed for preparation of tablets possessing optimized characteristics (batches AA13 to AA21). The percentage of crospovidone (X1) and mannitol (X2) were selected as independent variables. Wetting time and disintegration time were selected as dependent variables (response; Y). Full and refined models were derived for the prediction of the response variabley. Based on the results of multiple linear regression analysis, it was concluded that lower disintegration time and wetting time could be obtained when X1 is kept at high level and X2 is kept at low level. Promising batch (batch AA18) was compared with two marketed samples (brand A and B) of rofecoxib tablets for in vitro drug release after 30 min in three dissolution media. Tablets of batch AA18 exhibited better drug dissolution after 30 min than, the tablets of brand A and B in all the dissolution media.