Abstract
Purpose :
Efficient topical treatment of ocular pathologies still remains as a challenge. In this context, the endowing of contact lenses (CL) with the ability to host/release active substances has been largely pursued; but none tested approach has yet proven to be easily implemented at industrial scale. Our purpose was to design a unique material which could be processed using broadly adopted and well stablished CL manufacturing technologies but which, at the same time, could simultaneously perform as versatile drug/demulcent release platform. This designed material benefits from the incorporation of cyclodextrins as hosting agents, but without hydrogel network structure alteration. Overall, it can be considered to be a game-changing material agent for the CL state-of- the-art.
Methods :
Several compositions of hydroxyethyl methacrylate-co-glycidyl methacrylate hydrogels were synthesized and then post-functionalizated with cyclodextrin. Subsequent uptake/release tests of a-lipoic acid, an antioxidant molecule which preserves corneal sensitivity, essential for the normal physiological function of the eye surface were carried out. Optimized composition was used to synthesize bottom discs at industrial scale which were transformed in CL applying the lathe cutting method. The cyclodextrin-decorated CL were evaluated regarding optical properties, oxygen permeability, swelling, ocular irritation, drug release and drug penetration through bovine cornea (using conventional eye drops as reference)
Results :
The designed cyclodextrin-decorated hydrogels showed full industrial-adequate properties to be used as CL, rendering remarkably high load amounts of α-lipoic acid (60 mg/g vs. 10 mg/g for conventional CL) and also sustained release for several hours. Bovine corneal permeability tests demonstrated that the released α-lipoic acid can efficiently accumulate into the cornea and eventually cross it, despite low concentration environments on lachrymal fluid.
Conclusions :
The designed material shows excellent processability properties and also remarkable affinity for target active substances. This proofs that cyclodextrin-decorated CL, be this either with or without graduation, offers new ways for the therapeutics of the eye pathologies and also for the prevention of CL discomfort syndrome, just by adequately choosing the cyclodextrin that best fits to the requirements of each drug/demulcent release.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.