Researchers at the University of Florida, found that UV-blocking contact lenses protected photosensitive drugs from degrading and showed that contact lenses could be an effective way to deliver photosensitive extended-release drugs.

The research team loaded UV-blocking and non-UV-blocking contact lenses with dexamethasone, an anti-inflammatory steroid medication that is sensitive to UV light, and measured the amount of drug which remained after exposing the contact lenses to a UV lamp.

After 20 hours less than 1% of the dexamethasone in the UV-blocking lens had degraded, compared to 85% degradation in the regular contact lens. A third contact lens loaded with vitamin E, which has UV-absorbing properties, had 30% of the drug degraded. While the results suggest that both UV-blocking lenses and Vitamin E prevent degradation, the UV-blocking lenses did so more effectively.  The researchers point out, however, that Vitamin E also improves drug stability and release profile.

Further information: http://journals.lww.com/optvissci/Abstract/publishahead/Photoprotection_and_Extended_Drug_Delivery_by_UV.98710.aspx