Lipid Prodrug Approach for Retina and Posterior Segment Disease

Abstract

An inch or less. That is the short distance an ocular drug must travel to reach a target site at the back of the eye. Research has traveled a long way over the past four decades in efforts to make this inch-long journey more successful. Delivering ocular drugs to their target tissues often requires them to traverse the fat–water–fat structure of the corneal barrier while ensuring minimum wastage through tear washout and systemic absorption. This is why delivering drugs effectively to the posterior of the eye is a challenge that many companies have worked to overcome. Treatment of diseases of the retina and posterior segment of the eye, such as age-related macular degeneration, cytomegalovirus retinitis, diabetic retinopathy, posterior uveitis, and retinitis pigmentosa, requires novel drug delivery systems for efficacious delivery of therapeutic drugs. This challenge has prompted the development of biodegradable and nonbiodegradable sustained release systems for injection or transplantation into the vitreous as well as drug-loaded nanoparticles, microspheres, and liposomes. These drug delivery systems utilize topical, systemic, subconjunctival, intravitreal, transscleral, and iontophoretic routes of administration. The focus of research has been the development of methods that will increase the efficacy of spatiotemporal drug application, resulting in more successful therapy for patients with posterior segment diseases. This chapter summarizes recent advances in the research and development of drug delivery methods of the posterior chamber of the eye, with special emphasis on the use of lipid prodrug approach.