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Surfactant-laden soft contact lenses for extended delivery of ophthalmic drugs

Paper ID Volume ID Publish Year Pages File Format Full-Text
9432 629 2009 12 PDF Available
Title
Surfactant-laden soft contact lenses for extended delivery of ophthalmic drugs
Abstract

Eye drops are inefficient means of delivering ophthalmic drugs because of limited bioavailability and these can cause significant side effects due to systemic uptake of the drug. The bioavailability for ophthalmic drugs can be increased significantly by using contact lenses. This study focuses on the development of surfactant-laden poly-hydroxy ethyl methacrylate (p-HEMA) contact lenses that can release Cyclosporine A (CyA) at a controlled rate for extended periods of time. We focus on various Brij surfactants to investigate the effects of chain length and the presence of an unsaturated group on the drug release dynamics and partitioning inside the surfactant domains inside the gel. The gels were imaged by cryogenic scanning electron microscopy (cryo-SEM) to obtain direct evidence of the presence of surfactant aggregates in the gel, and to investigate the detailed microstructure for different surfactants. The images show a distribution of nano pores inside the surfactant-laden hydrogels which we speculate are regions of surfactant aggregates, possibly vesicles that have a high affinity for the hydrophobic drug molecule. The gels are further characterized by studying their mechanical and physical properties such as transparency, surface contact angle and equilibrium water content to determine their suitability as extended wear contact lenses. Results show that Brij surfactant-laden p-HEMA gels provide extended release of CyA, and possess suitable mechanical and optical properties for contact lens applications. The gels are not as effective for extended release of two other hydrophobic ophthalmic drugs, dexamethasone (DMS) and dexamethasone 21 acetate (DMSA) because of insufficient partitioning inside the surfactant aggregates.

Keywords
Surfactant-laden gels; Contact lenses; Cyclosporine A; p-HEMA; Transport; Modeling; Microstructure; Brij; Hydration; Viscoelasticity; Moduli; Wettability
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Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 30, Issue 5, February 2009, Pages 867–878
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us