Abstract
Purpose:
To report the in vivo testing of a dexamethasone-eluting contact lens designed for the treatment of ocular inflammation.
Methods:
Drug-eluting therapeutic contact lenses (TCL) were created by encapsulating dexamethasone-Poly(lactic-co-glycolic acid) films in methafilcon A by ultraviolet light polymerization. TCLs were inserted on the left eye of New Zealand white rabbits (n=4) for 7 days. The eyes were examined under an operating microscope and the anterior chamber (AC) fluid was collected each day over the course of one week of continuous wear. In addition, TCL’s were placed on the left eye of rabbits, which were euthanized 6 hours or 24 hours later. Drug concentrations were measured by high-performance liquid chromatography in combination with high-resolution mass spectrometry (LC-MS).
Results:
In vivo, the TCLs demonstrated no signs of toxicity. The TCL demonstrated a large early burst with followed by a steady state delivery rate that remained well above therapeutic levels for one week. Through 4 days of continuous wear, TCLs delivered more drug to the anterior chamber each day than dexamethsone drops administered every hour. After 24 hours of TCL, tissue drug concentrations (ng/g) were equal to or greater than reported values for hourly drops for all tissues tested: cornea (9,381 + 154), sclera (734 + 170), aqueous humor (1,224 + 190), iris (2,268 + 306), vitreous (91 + 25), retina (934 + 638), and choroid (667 + 149).<br />
Conclusions:
<br /> This contact lens design can potentially be used as a treatment for ocular inflammation and as a platform for ocular drug delivery with widespread applications.