Corneal efflux transporter (None)

Corneal efflux transporters are a group of membrane proteins—most notably members of the ATP-binding cassette (ABC) family, such as P-glycoprotein (MDR1/ABCB1), multidrug resistance-associated proteins (MRP1-6/ABCC1-6, especially MRP2 and MRP5), and breast cancer resistance protein (BCRP/ABCG2)—that actively pump a broad range of drugs and endogenous compounds out of corneal epithelial cells. Their primary physiological role is to protect ocular tissues from xenobiotics and regulate the penetration of therapeutic agents into the anterior chamber. These transporters form a major barrier for topical ocular drugs, often resulting in reduced bioavailability and therapeutic efficacy. They are upregulated in certain conditions and respond to pharmacological inhibitors, making them relevant targets in drug delivery strategies aiming to improve ocular absorption or overcome chemoresistance in diseases such as ocular cancer, inflammation, and infection. While collectively referred to as "corneal efflux transporters", each transporter has its own molecular identity, substrate preferences, and tissue localization within the cornea.

Other names

Corneal ABC transporterMultidrug resistance protein (MDR protein, MDR1/P-gp, ABCC1-6/MRP1-6, ABCG2/BCRP)Corneal outward transporterCorneal drug efflux pump

Inhibition of efflux proteins (by specific inhibitors such as verapamil, MK-571, FTC, GF120918) to enhance drug bioavailability; Efflux of substrate drugs across corneal epithelium (resulting in decreased therapeutic efficacy unless modulated)