The purpose of the research work was to develop a floating drug delivery System of ritonavir (RN) in order to prolong the gastric resideııce time and im rense its bioa\’ailability. The floating tablets of RN were prepared bv direct compression techniqııe, using polymers such as different grades of hydroxypropvl methyfçellulose (HPMÇ, Methocel E15LV, E50LV, K100LV and K4M) and poly\’invl pvrrolidone (PVP K30). Sodiıım bicarbonate w as used as gas releasing agent. The formıdations w ere optimized on the basis of matris integritv, duration offloating, swelling behavior and in vitro drug release. Escept series FA, w here floating time was 10 hr, other series such as FB, FC and FD w ere showing more than 12 hr offloating time. The highest average swelling index of 170.68 ± 0.45 was found in FD3 batch. The in vitro drug release indicated estended release of RN and more than 62 percent of drug was released at the end of the 12 hr for ali the batches, The mechanism of RN release from the floating tablets for FA, FB and FC series is anomaloııs diffusion transport andfollows zero order kinetics, but FD series indicated Higuchi kinetics with release rate esponent (n) of 0.44. Further, the scanning electron microscopy showed porous structured formed on the tablet surface at different times (0, 3, 6, 9 and 12 hr) of dissolution for the selected batch FC3. Finallv, FC3 batch showed no signifıcant change in above parameters after storage atroom temperature (28-32°C% 40°C and 50°Cfor one month.
Keywords: Ritonavir, Floating tablet, Estended release, Higuchi kinetics, Gas formation.\r\n