Formulation and evaluation of rofecoxib capsules

Rofecoxib [ROF] is an analgesic, antipyretic and anti-inflammatory drug. It is a selective inhibitor of cyclooxygenase enzyme [Cox-2 inhibitor]. The aim of this work was to formulate and evaluate ROF capsules and compare them with a commercial ROF product. The ROF capsules were prepared using different excipients namely: Sta-Rx starch 1500, cellactose, anhydrous lactose and tablettose. Compatibility of the drug with the used excipients was studied by differential scanning calorimetry. The effect of cogrinding of ROF with either PVP 40000 or Avicel PH 101 in the ratio of 1:5 w/w on the drug release from the prepared capsules was also studied. Differential scanning calorimetry and x-ray diffraction studies showed reduction in crystallinity or conversion of the drug to an amorphous form upon grinding with either PVP 40000 or Avicel PH 101 respectively. All formulae of ROF capsules complied with the USP XXV requirements for uniformity of dosage units. Formulae No. 6 and 7 containing ground mixture of the drug with either PVP 4000 or Avicel PH 101 in a ratio of 1:5 drug to carrier and Sta-Rx starch 1500 as diluent gave a higher dissolution rate of ROF [t[50%] = 5 and 9 min., respectively] in comparison with the commercial ROF product Rhumacure [t[50%] = 25 min.] Moreover; the anti-inflammatory activity was studied in rats using paw-edema method and the results obtained were analyzed using ANOVA test at the level of significance [P

Formulation and evaluation of rofecoxib tablets in comparison with marketed product

Rofecoxib [ROF] is an analgesic anti-inflammatory drug. It is a selective inhibitor of cyclooxygenase enzyme [Cox-2]. The aim of this work was to prepare and evaluate ROF tablets with higher dissolution rates and higher activity and to compare them with the marketed product. Direct compression technique was adopted for preparation of ROF tablets using different excipients namely; Sta-Rx starch 1500 or mixture of anhydrous lactose and microcrystalline cellulose Avicel pH 101 [1:1 w/w. ratio]. The effect of co-grinding method of ROF with either-polyvinyl pyro-lidone [PVP] 40000 or Avicel pH 101 in a ratio of 1:5 w/w on the drug release from the prepared tablets was also studied. All the tablet quality control tests and the thermal behavior were studied. The anti-inflammatory activity was also studied in rats using paw-edema method and the results were investigated by statistical analysis using ANOVA test at the level of significance [P = 0.05]. All formulations of ROF tablets showed good mechanical properties and complied with the USP XXV pharmacopeial standard requirements for uniformity of dosage units and friability. Differential scanning calorimetry showed transformation of the drug to the amorphous form. Formulae No. 2, 3 [containing co-ground mixture of the drug with either PVP 40000 or Avicel pH 101 and Sta-Rx starch 1500] gave higher percentage of ROF release [t[50%] = 15, 9 min. respectively,] in comparison with the marketed product [t[50%] = 25 min]. It was found also that the prepared ROF tablets show superior anti-inflammatory activity in comparison with the marketed product upon analysis of data using ANOVA test