Molecularly imprinted therapeutic contact lenses
Authors: White, Charles J; Byrne, Mark E
Source: Expert Opinion on Drug Delivery, Volume 7, Number 6, June 2010 , pp. 765-780(16)
Publisher: Informa Healthcare
Abstract:Importance of the field: There exists a considerable unmet need for more efficacious delivery of ocular therapeutics. Contact lenses have been developed with high loading and controllable sustained release to overcome limited patient compliance and significant ocular transport limitations. This can best be achieved by extending and controlling the residence time of drugs on the eye surface and thereby limiting drug loss by lacrimation, drainage and non-productive absorption.
Areas covered in the review: Within hydrogels, molecular imprinting can be used to create memory for template molecules embedded within a flexible macromolecular network. Control in therapeutic loading and delay of release have been demonstrated with careful attention to the functional monomer/template ratio, the diversity of functional monomers, and the polymer backbone and network structure. Experimental work has also confirmed that macromolecular memory and not structural differences or phenomena are responsible for delayed drug release kinetics compared with non-imprinted systems. A therapeutically relevant amount of drug can be loaded for release to occur over multiple days, which allows the technique to be applied to daily-wear and extended-wear contact lenses.
What the reader will gain: The focus of this article is to review the emerging field of molecularly imprinted contact lenses and highlight significant accomplishments, trends, as well as future strategies and directions.
Take home message: In the past 8 years, molecular imprinting has been used to produce therapeutic contact lenses with enhanced loading and delayed release. Progress in the field has mostly included low-molecular-weight therapeutics such as anti-glaucoma, antihistamine, antibiotic and anti-inflammatory therapeutics used to treat anterior eye disorders. Recently, high molecular weight comfort molecules have also been successfully demonstrated. Current methods can produce lenses of suitable thickness, water content, and mechanical and optical properties compared with commercial lenses on the market today.
Keywords: anti-inflammatory; antibiotic; antihistamine; beta blocker; combination device; comfort molecule; contact lens; controlled release; drug delivery; macromolecular memory; molecular imprinting; ophthalmology
Document Type: Research Article
Publication date: 2010-06-01