Bioavailability and pharmacokinetic studies of rofecoxib solid dispersion.

The present investigation deals with the determination of bioavailability of Rofecoxib solid dispersion compared to pure rofecoxib (RFB). The study of a non-blinded, open-label, crossover design was conducted in six healthy volunteers. Blood samples were collected for 12 h at specified intervals of time after the administration of formulations and analysed by suitable HPLC method. The pharmacokinetic parameters such as maximum plasma concentration (Cmax), time to reach (tmax), elimination rate constant (Kel) biological half-life (t1/2), absorption rate constant (Ka) and area under curve (AUC0-12 and AUC0-) were determined. Significant difference in the bioavailability of pure rofecoxib and solid mixture of rofecoxib prepared using hupu gum as carrier has been reported from the studies. The Peak plasma concentrations (Cmax) of 8.34 ng/mL at tmax of 4 h and Cmax of 76.84 ng/mL at tmax of 3 h were observed for RFB and solid mixture respectively. The results clearly indicated an enhancement in the bioavailability of rofecoxib in solid mixture preparation.