Implants as drug delivery devices for the treatment of eye diseases

The treatment of diseases affecting the posterior segment of the eye is limited by the difficulty in transporting effective doses of drugs to the vitreous, retina, and choroid. Topically applied drugs are poorly absorbed due to the low permeability of the external ocular tissues and tearing. The blood-retina barrier limits drug diffusion from the systemic blood to the posterior segment, thus high doses of drug are needed to maintain therapeutic levels. In addition, systemic side effects are common. Intraocular injections could be an alternative, but the fast flowing blood supply in this region, associated with rapid clearance rates, causes drug concentration to quickly fall below therapeutic levels. To obtain therapeutic levels over longer time periods, polymeric sustained-drug release systems implanted within the vitreous are being studied for the treatment of vitreoretinal disorders. These systems are prepared using different kinds of biodegradable or non-biodegradable polymers. This review aims to demonstrate the main characteristics of these drug delivery implants and their potential for clinical application.

Bibliographic Details

Main Authors:	Silva,Gisele Rodrigues da, Fialho,Sílvia Ligório, Siqueira,Rubens Camargo, Jorge,Rodrigo, Cunha Júnior,Armando da Silva
Format:	Digital revista
Language:	English
Published:	Universidade de São Paulo, Faculdade de Ciências Farmacêuticas 2010
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000300024
Tags:	Add Tag No Tags, Be the first to tag this record!