Tabriz University of Medical Sciences Advanced Pharmaceutical Bulletin 2228-5881 6 2 2016 06 30 Development of Floating-Mucoadhesive Microsphere for Site Specific Release of Metronidazole 195 200 10.15171/apb.2016.027 EN Md. Lutful Amin Tajnin Ahmed Md. Abdul Mannan Journal Article 10.15171/apb.2016.027 2015 08 01 2016 04 24 Purpose: The purpose of this study was to develop and evaluate metronidazole loadedfloating-mucoadhesive microsphere for sustained drug release at the gastric mucosa.Methods: Alginate gastroretentive microspheres containing metronidazole were preparedby ionic gelation method using sodium bicarbonate as gas forming agent, guar gum asmucoadhesive polymer, and Eudragit L100 as drug release modifier. Carbopol was used forincreasing the bead strength. The microspheres were characterized by scanning electronmicroscopy and evaluated by means of drug entrapment efficiency, in vitro buoyancy, andswelling studies. In vitro mucoadhesion and drug release studies were carried out in order toevaluate site specific sustained drug release.Results: All formulations showed 100% buoyancy in vitro for a prolonged period of time.Amount of guar gum influenced the properties of different formulations. The formulationcontaining drug and guar gum at a ratio of 1:0.5 showed the best results with 76.3% drugentrapment efficiency, 61.21% mucoadhesion, and sustained drug release. Carbopol wasfound to increase surface smoothness of the microspheres.Conclusion: Metronidazole mucoadhesive-floating microspheres can be effectively usedfor sustained drug release to the gastric mucosa in treatment of upper GIT infection.