Drug Delivery to Anterior Segment of the Eye

Transport of therapeutic agents into the anterior segment of the eye is highly restricted by various anatomical and physiological barriers. Topical administration is the most convenient method of drug delivery for the treatment of anterior segment eye diseases. The global market for eye care products is approximately $12.5 billion and is growing at a rate of 9% every year. Eye drops account for 90% of all conventional ophthalmic formulations. However, it suffers from several disadvantages such as nasolacrimal drainage, loss in conjunctival blood circulation, tear dilution, normal tear drainage and reflux blinking. There is a need for alternate drug delivery systems which can address poor ocular absorption associated with conventional drug delivery systems. In this chapter, we have made an attempt to briefly describe various drug delivery systems employed in the treatment of anterior segment eye diseases such as nanoemulsions, collagen corneal shields, hydrogels, vesicular systems (liposomes and niosomes), iontophoresis, phonophoresis, punctal plugs and contact lenses.

Keywords: Eye, anterior segment, novel systems, drug delivery, nanoemulsions, collagen corneal shields, hydrogels, vesicular systems, iontophoresis, phonophoresis, punctal plugs, contact lenses.