Extended delivery of hydrophilic drugs from silicone-hydrogel contact lenses containing vitamin E diffusion barriers.
This paper proposes an approach for increasing drug release durations from contact lenses and other biomedical devices by in situ creation of transport barriers of Vitamin E that force drug molecules to diffuse through long tortuous path. Results show that the increase in release duration is quadratic in Vitamin E loading, which is consistent with proposed mathematical models. Loadings of 10 and 40% Vitamin E increase release time of timolol by a factor of about 5 and 400, respectively for NIGHT&DAY lens. Similar results have been obtained for other hydrophilic drugs including fluconazole and dexamethasone 21-disodium phosphate (DXP). Vitamin E loading in the NIGHT&DAY lens leads to slight increase in lens sizes (6.5% increase for 30% loading), a slight reduction in oxygen diffusion (about 40% reduction for 75% loading), and a more significant reduction in the ion permeability (50% reduction for 10% loading). Additionally, Vitamin E loading has a beneficial effect of blocking UV radiation which will reduce the corneal damage due to UV light.
Department of Chemical Engineering, University of Florida, Gainesville, FL 32611-6005, USA.
Cheng-Chun
CC
Peng
Jinah
J
Kim
Anuj
A
Chauhan
D018639:Contact Lens Solutions; D003263:Contact Lenses, Hydrophilic; D003907:Dexamethasone / Q000031:analogs & derivatives / Q000494:pharmacology; D004058:Diffusion / Q000187:drug effects; D016503:Drug Delivery Systems / Q000379:methods*; D015725:Fluconazole / Q000494:pharmacology; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D007477:Ions; D008956:Models, Chemical; D010100:Oxygen / Q000378:metabolism; D010539:Permeability / Q000187:drug effects; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D012828:Silicones / Q000737:chemistry*; D013999:Timolol / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology*; D014867:Water / Q000737:chemistry
D018639:Contact Lens Solutions; D007477:Ions; D004364:Pharmaceutical Preparations; D012828:Silicones; D014867:Water; D014810:Vitamin E; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C004180:dexamethasone 21-phosphate; D003907:Dexamethasone; D013999:Timolol; D015725:Fluconazole; D010100:Oxygen