An Overview of Recent Patents on Nanocarrier Based Ophthalmic Drug Delivery Systems

Nanomedicine is one of the most promising drug delivery technologies. Treatment of anterior or posterior segment ocular diseases has always been a challenging task. The primary constraint to ophthalmic drug delivery is to deliver therapeutics at the target tissue without altering protective physiological mechanisms of the eye. In the last decade, research advancements in the field of nanotechnology have met many challenges for the treatment of ocular diseases. These nanomedicines have been employed to improve stability, solubility and ocular bioavailability, and also to reduce eye irritation caused by drug candidate or the formulation. This review article is focused on the patents issued for ophthalmic formulations particularly nanomedicines during the period of 2000-2011. The patents on nanomedicines are classified in different categories such as liposomes, polymeric nanoparticles, dendrimers, micelles and nanoemulsion. Moreover, this review article also discusses the patents in which two approaches (such as nanoparticles suspended in contact lens, nanoemulsion in situ gelling system and nanoparticles delivered via iontophoresis) are combined to achieve the best formulation for ocular treatments.