Ocular application of chitosan.

INTRODUCTION: A major problem in ocular therapeutics with classical formulations is the maintenance of an effective drug concentration at the site of action for a long period of time. Enhancement of ocular bioavailability with increased dose penetration and longer retention time at desired sites can be achieved by recent formulations. Chitosan stands out with its unique structural advantageous characteristics for different types of formulations like in situ gelling systems, micro- and nanoparticles, inserts, etc. AREAS COVERED: In this review, the authors focus on ocular therapeutics and the characteristics that make chitosan more acceptable in ocular applications. EXPERT OPINION: Chitosan seems to be one of the most promising polymeric carriers for both hydrophilic and lipophilic drugs for ocular application.