Uptake and Release of Ciprofloxacin by Soft Contact Lens Materials Loaded With Hyaluronic Acid

Abstract

Purpose: : The purpose of this study was to determine the effect of hyaluronic acid (HA) in model conventional hydrogel and silicone hydrogel (SH) materials on the uptake and release of the fluoroquinolone antibiotic ciprofloxacin, and to evaluate the potential of these materials as ocular drug delivery devices.

Methods: : A 3 mg/ml ciprofloxacin solution (0.3%) was prepared in borate buffered saline. Three hydrogel material samples (pHEMA; pHEMA TRIS; DMAA TRIS) were prepared with and without HA of molecular weight (MW) 35 or 132 kDa. Hydrogel discs were punched out from a sheet of material with a uniform diameter of 5mm. Uptake kinetics were evaluated at room temperature by soaking the discs in 0.3% ciprofloxacin for 24 hours. Release kinetics were evaluated by placing the drug-loaded discs in saline at 34°C in a shaking water bath. At various time points over 6 days, aliquots of the releasate were removed and ciprofloxacin amounts determined by fluorescence spectroscopy.

Results: : All materials released sufficient drug to meet the MIC 90 for most common bacterial isolates (0.00025 to 0.032 mg/ml). Overall, the silicone-based hydrogels (pHEMA TRIS and DMAA TRIS), released lower concentrations of ciprofloxacin than the conventional pHEMA material (p<0.001). Materials with HA MW132 released more ciprofloxacin compared to materials with HA MW35 and lenses without HA (p<0.02). HA-based materials were still releasing the drug after 6 days.

Conclusions: : HA-containing hydrogel biomaterials show much promise as antibiotic drug delivery devices, for periods up to 1 week.

Keywords: contact lens • antibiotics/antifungals/antiparasitics