Considering the low ocular bioavailability of conventional formulations used for ocular bacterial infection treatment, there is a need for developing efficient modern drug delivery systems. Main attempt in this study was to extend the interaction of the carrier with negatively charged ocular surfaces for enhanced penetration from both corneal and non-corneal sites in order to improve ocular bioavailability. Self-cationic, mucoadhesive and permeation-enhancing characters make chitosan an ideal polymer for ocular application of active agents. In this study ornidazole incorporated chitosan nanoparticles were prepared by spray-drying process. In vitro characterization showed that enhanced ocular bioavailability could be achieved by non-toxic chitosan nanoparticles.