Research progress on ophthalmic drug delivery systems

Due to the special physiological structure and the existence of barriers, traditional ocular preparations having some disadvantages of low bioavailability, short retention time and strong irritation in ocular, are difficult to achieve target treatment effect. Recently, with the application of various new technology, such as nano preparations, implants and contact lenses, et al, ocular drug delivery systems have made a great progress. Nanomaterials including polymeric micelles, nanoparticles, nanosuspensions, liposomes and nanoemulsions, etc, have been widely used for ocular drug delivery system, because they have the characteristics of small size, degradability, strong targeting and little irritation to biological tissues. Currently, the above new technologies have shown good application prospects in ocular drug delivery systems. In this paper, the development in these areas in recent years are reviewed in order to provide reference for the development of ocular drug delivery systems.