Ion activated in situ gel system for ophthalmic delivery of moxifloxacin hydrochloride

Rapid precorneal elimination of drug is a major limitation of conventional ophthalmic formulations. An ion activated in situ gel forming systems of an antibacterial agent moxifloxacin hydrochloride for instillation as drops into eye undergoing a sol to gel transition in the cul-de-sac was formulated. Sodium alginate was used as the gelling agent in combination with hydroxypropylmethyl cellulose. Formulations were evaluated for gelling capacity, pH, in vitro release, rheological study, Draize eye irritation test and storage stability. Systems exhibited pseudoplastic rheology, evidenced by shear thinning with increase in shear stress and increased angular velocity. The in vitro release rate of moxifloxacin hydrochloride from gel decreased as an inverse function of polymer concentration. The optimized products were stable and non irritant. Equal amounts of sodium alginate and hydroxypropylmethyl cellulose exhibit encouraging rheological properties with therapeutically effective and non-irritant product. This in situ gel system can be a viable alternative to conventional eye drops. Colegio de Farmacéuticos de la Provincia de Buenos Aires