The objective of the present investigation is to formulate multiparticulate gastroretentive dosage form of Nizatidine, a H2-receptor antagonist widely prescribed in gastric ulcers, duodenal ulcers. The short biological half-life (1 -2 hours), maximum absorption in initial part of small intestine, colonic metabolism of Nizatidine favors, development of gastro retentive floating dosage form. The present study involves preparation and evaluation of floating microspheres prepared by solvent evaporation and spray drying method using polymers HPMC and EC with Nizatidine as model drug for prolongation of gastric residence time. The drug-excipient compatible studies performed using FTIR and DSC and study revealed that there is no drug-excipient interaction. The central composite design was employed to evaluate contribution of HPMC: EC and SET: SDT technique on entrapment efficiency and percentage of drug release of floating microspheres. The prepared multiparticulate system were evaluated for various physicochemical parameters such as flow properties, in-vitro buoyancy (floating lag time, total floating time), swelling studies, drug content and in-vitro drug release. The shape and surface morphology of prepared microspheres were characterized by optical and scanning electron microscopy, respectively Size of the microparticle ranged from 5-20 μm expressing that microparticle are spherical and non-aggregated. As the mean particle size increased, the drug release rate decreased at higher polymer concentration. In this study it was found that spray drying was effective method to produce floating microparticles successfully without use of solvents like dichloromethane, which is a class II solvent or aromatic solvents like ethyl acetate. Microparticles were evaluated for buoyancy and drug release study using paddle type dissolution apparatus using pH 1.2 buffer as dissolution medium. The in vitro drug release pattern of Nizatidine floating microspheres was fitted to different kinetic models which showed highest regression for zero order kinetics with non fickian diffusion mechanism and prepared microspheres exhibited prolonged drug release (8 h) and remained buoyant for >10 h.
Loading....