Studies on a new device for drug delivery to the eye.

Delivery of drugs to the anterior side of the eye is routinely done with eye drops, but this method results in low bioavailability and low patient compliance. Herein, we describe a new device for the delivery of drugs to the eye. The device, called the OphthaCoil, consists of a drug-loaded adherent hydrogel coating on a thin metallic wire, which is coiled. The drug release rates of the dye fluorescein and the antibiotic chloramphenicol have already been evaluated in vitro. In this report the drug release rate of the anti-infective pradofloxacin was evaluated in vitro and in vivo. The data show that the OphthaCoil is capable of sustained drug delivery to the tear film in dogs. Drug levels in the tear fluid of the dogs were well above the MIC-values of relevant bacteria after 16 h, but it should be noted that pradofloxacin has an exceptionally high antimicrobial activity. The study indicates that the OphthaCoil holds promise as a platform for sustained release of drugs to the eye. The device was well tolerated, but the devices were lost when left overnight. Most probably, this is due to the third eyelid pushing the device out of the conjunctival sac during sleep. It should be noted that this complication has no immediate implication for extended wear of the OphthaCoil in humans, as humans do not have third eyelids.