DEVELOPMENT AND IN VIVO EVALUATION OF GASTRORETENTIVE FLOATING TABLETS OF ANTIPSYCHOTIC DRUG RISPERIDONE

Objective: The objective of this research work was to formulate and evaluate the floating drug delivery system containing Risperidone, to improve oral bioavailability by increasing gastric residence time.Methods: Total fifteen formulations of Risperidone floating tablets were prepared by direct compression method using different grades of HPMC polymers, Gelucire, Polyox and NaHCO3. In vivo radiographic studies were performed in human volunteers by incorporating barium sulphate.Results: The prepared tablets were characterized and found to exhibit satisfactory physicochemical characteristics. All the prepared batches showed good in vitro buoyancy with low floating lag time. It was observed that the tablets remained buoyant for more than 12h. Optimized formulation (F15) consisting of HPMC K100M, WSR 301, Gelucire 50/13 and NaHCO3, followed diffusion controlled zero-order kinetics and non-fickian transport of the drug. FTIR and DSC studies revealed the absence of any chemical interaction between drug and polymers used. The in vivo radiographic studies revealed that the tablets remained in the stomach for 6h in fasting human volunteers. In vivo bioavailability studies performed in healthy human volunteers and Tmax, Cmax, AUC was calculated and confirmed significant improvement in bioavailability when compared with marketed formulation Respidon 2.Conclusion: The data obtained thus suggests that floating delivery system of Risperidone can be successfully designed to give controlled drug delivery and improved oral bioavailability.