Ophthalmic drug delivery by contact lenses

Ophthalmic drugs are almost always delivered via eye drops in spite of many deficiencies including low bioavailability and poor compliance, particularly in patients requiring multiple eye drops daily. Only about 1-5% of the drug in eye drops diffuses into the cornea and the remaining 95-99% enters systemic circulation through multiple pathways including tear drainage and conjunctival absorption. Contact lenses are placed directly on the cornea with a thin 5-10 micron thick post-lens tear film (POLTF) layer in between, which makes contacts a natural choice for delivering drugs to the cornea. The drug released by the contact towards the cornea surface is trapped in the POLTF for extended duration of at least 30 min allowing transport of a large portion into the cornea. Our model predictions backed by in vivo animal data show that the bioavailability increases to about 50% with contact lenses.

Speaker: Anuj Chauhan, colorado School of Mines