Controlled Drug Delivery through Soft Contact Lenses using Graphene Oxide

Abstract

Cyclosporine eye drop solution is widely used to manage dry eye syndrome (DES). However, they need frequent dosing affecting the routine life style of patient. Ocular drug delivery using contact lenses can substitute the eye drop therapy. But, the issues with hydrophobic drug (like cyclosporine) such as low drug uptake using a soaking method into preformed contact lenses and alteration in the swelling and transmittance of lenses restricts its application. This research uses graphene oxide (GO) to control the release of cyclosporine from contact lenses along with improvements in the drug uptake, release kinetics, water content (lens swelling) and transmittance. Graphene oxide (GO) is an atomically-thin sheet of carbon atoms laced with oxygen containing functional groups and possess a large surface area which enables high drug loading with improved swelling and transmittance. GO was incorporated into lenses during lens polymerization. These GO-laden contact lenses (SM-GO-Cys) as well as blank contact lenses (SM-Cys) were soaked in the solution of cyclosporine. Alternatively cyclosporine-GO-laden contact lenses (DL-Cys-20-GO) and cyclosporine-laden contact lenses (DL-Cys-20) were fabricated by adding drug-GO and drug during polymerization, respectively. GO improved the water holding capacity (swelling and contact angle data) of both soaked and direct loaded contact lenses due to hydrogen bonding between GO and water molecules. The significant improvement in the transmittance of GO-laden contact lenses was noted due to molecular dispersion of cyclosporine on the surface of GO. The drug uptake and in vitro release profile was improved with GO-laden contact lenses by soaking method (SM-GO-Cys-400n) which can be attributed to the hydrophobic interactions between GO and cyclosporine.