APPLICATIONS OF NOVEL VESICULAR DRUG DELIVERY SYSTEM AS OCULAR DRUG VEHICLES: A REVIEW

The eye is the most easily reachable organ available for topical drug delivery of local as well as interiorly acting drugs. Ideal drug delivery system aims to provide loading and maintenance dose of drug while being within therapeutic limits at the desired site of action for the desired period of time. In the treatment of ocular disease, the site of action is very narrow and undesired side effects may cause serious injuries to eye tissues. Thus, ideal ocular drug delivery should be site specific, controlled release and non-irritating. Many drugs (more than 85%) belong to BCS class IV exhibiting poor solubility and permeability. Moreover; the precorneal losses like tear secretion, naso-lachrymal drainage and less permeability of corneal tissue causes only 1% absorption of instilled dose. These limitations lead to increased loading dose and dosing frequency to maintain minimum therapeutic level for action which ultimately causes over exposure of drug to eye and leads to serious side effects. Due to these hurdles of conventional drug delivery system, the vesicular drug delivery system is gaining more popularity day by day as they offer improved permeability and altered bioavailability of drug. These formulations mainly include liposome and niosome made up of phospholipids and non-ionic surfactants respectively. They are non-antigenic, biodegradable and non-irritating. The present article reveals the key-work done on vesicular drug delivery system as potential ocular drug delivery system and justifies the need for further research on vesicular drug delivery system as ocular vehicles.