Extended delivery of hydrophilic drugs from silicone-hydrogel contact lenses containing Vitamin E diffusion barriers
✍ Scribed by Cheng-Chun Peng; Jinah Kim; Anuj Chauhan
- Book ID
- 104003967
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 1021 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0142-9612
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✦ Synopsis
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&DAYÔ lens. Similar results have been obtained for other hydrophilic drugs including fluconazole and dexamethasone 21-disodium phosphate (DXP). Vitamin E loading in the NIGHT&DAYÔ 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.