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Preparation and Evaluation of Floating Microspheres of Ritonavir.

Syed Ershad, V Sai Kishore, U Kartheek, M Sandeep, K Prameela Rani, and K Adithya

Floating microspheres of Ritonavir was prepared by ionic gelation method with an aim of increasing the gastric residence time and for controlled release. Sodium alginate, polymeric mixture of Sodium alginate and Guargum were used as polymers. Sodium bicarbonate was used as the gas-forming gent. The prepared floating microspheres were evaluated with respect to particle size distribution, floating behaviour, drug content, entrapment efficency, morphology and in vitro release study. These results indicated that the release rate was found to decrease with increase in concentration of coating material applied. The wall thickness of microspheres was found to be increased with the increase in concentration of coating material applied. The floating microspheres followed zero order kinetics and the mechanisam of drug release was governed by peppas model. For all the microspheres the exponential coefficient values were found to be in between 0.7664 and 0.8565., indicating non fickian diffusion controlled release mechanism.