Topical application is the preferred route of administration for bacterial conjunctivitis and keratitis because the drops provide therapeutically effective concentrations; the drops wash away bacteria and bacterial antigens; adverse systemic effects of the drugs are decreased or eliminated. Our present work describes the formulation and evaluation of an ocular delivery system of ofloxacin based on the concept of an ion activated in situ gelling system. Gellan alone was investigated as vehicle for the formulation of eye drop of ofloxacin which undergoes gelation when instilled into the cul-de-sac of the eye. The developed formulation was characterized for pH, clarity, in vitro drug release profile, transcorneal permeation profile, ocular irritation and in vivo precorneal drainage study. In situ gel forming ability of the developed system significantly controls precorneal drainage as studied by gamma scintigraphy. The formulation was also found to be nonirritant and well tolerable. The developed in situ gelling system form good clear gel over the corneal surface immediately after administration. In situ gel forming ability of the developed system significantly controls precorneal drainage; thus increased residence time in the eye that would help to increase ocular bioavailability.
