A REVIEW ARTICLE ON OCCULAR DRUG DELIVERY SYSTEM

The scientist’s faced many challenges in Ocular drug delivery system due to unique anatomy and physiology of eye. In ocular drug delivery system there are two types of barriers static and dynamic barrier.  Static barriers consist of different segment of eye such as cornea, sclera, retina and blood- retinal barriers. In other way dynamic barriers consists choroidal and conjunctival blood flow, lymphatic clearance, and tear dilution.  These both barriers affect the bioavailability of drugs. In recent year some new concept of drug delivery such as iontophoresis, liposome bio adhesive gels, ocular insert, contacts lenses etc.  Has been developed to overcome problems associated by static and dynamic barriers. These formulation-based approaches have high capacity to carry maximum concentration of drug at targeted site   of eye.

Therefore, a demand for improved cell culture that can replace animal experimentation with an adequate reproducibility is mandatory. Corneal epithelial cell culture models are the longer-considered strategy to study in vitro ocular drug delivery. From these, rabbit and human cell lines are the most frequently used. Primary cells have been employed that were transformed by using some chemicals or viruses to establish continuous/immortalized cells. Alternatively, original immortalized cells because of a tumour were also employed. Additionally, some attempts have been made to develop a tridimensional corneal structure.

Key Words: Ocular Drug Delivery System, Intra Ocular Barriers