Drug delivery to the posterior segment of the eye for pharmacologic therapy

Abstract

Treatment of diseases of the 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 that can overcome the many barriers for efficacious delivery of therapeutic drug concentrations. 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 article summarizes recent advances in the research and development of drug delivery methods of the posterior chamber of the eye, with an emphasis on the use of implantable devices as well as micro- and nanoparticles.

Keywords::

• biodegradable
• drug delivery
• intravitreal
• iontophoresis
• microbubbles
• microspheres
• nonbiodegradable
• subconjunctival
• sustained release
• transscleral

Financial & competing interests disclosure

The authors are supported in part by NIH grants EY006311 (James M Hill), EY019144 (Partha S Bhattacharjee) and EY02377 (LSU Eye Center Core Grant for Vision Research), by a Research to Prevent Blindness Senior Scientific Investigator Award (James M Hill), by the Louisiana Vaccine Center and the South Louisiana Institute for Infectious Disease Research sponsored by the Louisiana Board of Regents (James M Hill), an unrestricted grant to the LSU Eye Center from Research to Prevent Blindness (NY, USA) and funding from the Louisiana Lions Eye Foundation, New Orleans and Lions International. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.