Formulation and Evaluation of Norfloxacin Ocular In-situ Gel

The study aims to prepare and evaluate the in situ Norfloxacin gel for the treatment of Conjunctivitis. The pronounced fluctuations and repeated administration of conventional eye drops are the main disadvantages of ophthalmic drug delivery. The ocular in situ gelling system is designed to achieve a prolonged therapeutic effect by improving residence time at the application site. Infrared spectroscopy studies of Norfloxacin, Sodium alginate, Gellan gum, and HPMC K4M alone and their physical mixture revealed that Norfloxacin is compatible with all the polymers used. The Ophthalmic in situ gelling system of Norfloxacin was successfully formulated using different gelling agents viz. Sodium alginate, Gellan gum, and HPMC K4M are viscosity-enhancing agents. Prepared in situ gels were subjected to evaluation such as visual appearance, pH, and drug content. All formulations were found transparent and clear, the pH of the formulations was between 7.1 to 7.4, and drug content was found within 95-98% in all in situ gelling systems. All the formulations showed instantaneous gelation when contacted with simulated tear fluid. The viscosity of all formulations decreased as the shear rate increased, indicating the pseudoplastic fluid's character. In vitro release of Norfloxacin from the prepared formulations was studied for 6 hours. Results reveal that all formulations exhibited sustained release of the drug from the gelrite polymeric network over 6 hrs. The stability studies confirmed that in situ gelling formulations of Norfloxacin remained more stable at ambient temperature and humidity. The present work was a satisfactory preliminary study in developing in situ gelling systems of Norfloxacin. Keywords: Conjunctivitis, Norfloxacin, in situ gel, Sodium alginate, sustained release.