CHARACTERIZATION AND EVALUATION OF NIZATIDINE FLOATING MICROSPHERES BASED DRUG DELIVERY SYSTEM FOR ANTI-ULCER ACTIVITY

Objective: The purpose of the present study to develop gastro-retentive drug delivery formulation for enhancing GRT, including the physiological and formulation variables affecting gastric retention. It is a widely employed approach to retain the dosage form in the stomach for an extended period and release the drug slowly that can address many challenges like poor bioavailability. Methods: Floating microspheres were prepared by solvent evaporation (oil-in-water emulsion) technique. In this 225 mg poly(methyl methacrylate) (PMMA) were dissolved in a mixture of dimethylformamide and dichloromethane (1:1) at room temperature. And 75 mg nizatidine hydrochloride was added in the above mixture. This was poured into 250 ml water containing 0.02% tween 80, maintained at a temperature 30 – 40 ºC and subsequent stirred at ranging agitation speed for 20 min to allow the volatile solvent to evaporate. The microspheres formed were filtered, washed with water and dried in vacuum. Results: The prepared floating microspheres were characterized in a different way like size distribution 131.4 ± 1.6 µm and 89.5 ± 1.4% entrapment efficiency was found, an in-vitro floating test of optimized floating microspheres formulation was studied in SGF (pH 1.2). The percent cumulative amount of drug release was found 87.2 ± 2.6% in SGF (pH 1.2), 90.2 ± 3.5% in SIF (pH 6.8) and 93.2 ± 3.5% in PBS (pH 7.4) up to 24 h. The ulcer protection of the microspheres formulation was 79.84% as compared to the nizatidine pure drug (66.05%) in ulcer induced rats. The C-max value of nizatidine as obtained from the graph was 575.14 ± 55.43 mg/ml with T-max value 2 h and for the formulation was 206.58 ± 7.71 mg/ml. Conclusion: Floating microspheres drug delivery system provides the possibility of enhancing the bioavailability and control the release of formulation exhibiting absorption window by prolonging the gastric emptying time of the dosage form ensuring availability of the drug at the absorption site for the desired period.