title: Extended ocular drug delivery systems for the anterior and posterior segments: biomaterial options and applications.
abstract: The development of new therapies for treating various eye conditions has led to a demand for extended release delivery systems, which would lessen the need for frequent application while still achieving therapeutic drug levels in the target tissues. Areas covered: Following an overview of the different ocular drug delivery modalities, this article surveys the biomaterials used to develop sustained release drug delivery systems. Microspheres, nanospheres, liposomes, hydrogels, and composite systems are discussed in terms of their primary materials. The advantages and disadvantages of each drug delivery system are discussed for various applications. Recommendations for modifications and strategies for improvements to these basic systems are also discussed. Expert opinion: An ideal sustained release drug delivery system should be able to encapsulate and deliver the necessary drug to the target tissues at a therapeutic level without any detriment to the drug. Drug encapsulation should be as high as possible to minimize loss and unless it is specifically desired, the initial burst of drug release should be kept to a minimum. By modifying various biomaterials, it is possible to achieve sustained drug delivery to both the anterior and posterior segments of the eye.
authors.affiliation: a Department of Biomedical Engineering , Illinois Institute of Technology , Chicago , IL , USA.
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Kang-Mieler
authors.affiliation: a Department of Biomedical Engineering , Illinois Institute of Technology , Chicago , IL , USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Dosmar
authors.affiliation: a Department of Biomedical Engineering , Illinois Institute of Technology , Chicago , IL , USA.
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Liu
authors.affiliation: b Department of Ophthalmology and Visual Sciences , University of Illinois at Chicago , Chicago , IL , USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Mieler
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005123:Eye / Q000378:metabolism*; D005128:Eye Diseases / Q000188:drug therapy*; D006801:Humans; D020100:Hydrogels; D008081:Liposomes; D008863:Microspheres
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D020100:Hydrogels; D008081:Liposomes
keywords: Anterior segment delivery; PLGA; drug delivery; eye; hydrogels; liposomes; microspheres; nanospheres; posterior segment delivery