In the present study, a novel floating oral drug delivery system was developed utilizing concept of controlled release in order to obtain a unique drug delivery system which could remain in the stomach and control the drug release for an extended period of time. Nizatidine microspheres were prepared by solvent evaporation and spray drying method by using polymers such as Hydroxy propyl methyl cellulose, Ethyl cellulose. Optimized batch was obtained by the Design of experiment. The prepared formulation was subjected to particle size and shape analysis, percentage drug entrapment efficiency, in-vitro floatability, in vitro drug release studies. The compatibility study of drug and polymer was carried out by IR, DSC, and XRD analysis. The polymer and drug were compatible to each other. The prepared microspheres were discrete, spherical with a mean particle size in the range 448 μm to 645μm for solvent evaporated microspheres, and 1-100μm for spray dried microspheres. Entrapment efficiency was found to be 60- 90% for solvent evaporated microspheres, and 60-80% for spray dried microspheres. In-vitro drug release for all the formulations in 0.1N HCL was diffusion controlled gradually over a period of 8hr and followed by first order kinetics. There was no significant change in physicochemical characteristics of the microspheres stored at room temperature for 1 month. The developed system has the dual advantages of being gastro-retentive, to increase oral bioavailability and releasing drug in a controlled manner, to reduce frequency of administration there by promoting patient compliance.
