Abstract

Mohd Suhail* and Kanchan Tariyal

ABSTRACT

Due to the unique architecture and physiology of the eye, drug delivery scientists and pharmacologists have faced significant difficulties. Delivery of a drug alone or in a dosage form, particularly to the posterior segment, is significantly hampered by the combination of static barriers (different layers of the cornea, sclera, and retina, including blood aqueous and blood-retinal barriers), dynamic barriers (choroidal and conjunctival blood flow, lymphatic clearance, and tear dilution), and efflux pumps. Innovative methods for the noninvasive administration of strong treatment drugs are becoming more popular in order to increase patient compliance for back of the eye illnesses. We address historical achievements, current inventions, and upcoming difficulties in ocular drug-delivery technology in this review paper. Due to the blood-ocular barrier, topical therapy is preferred for treating ophthalmic conditions. Solutions, suspensions, and ointments are the most often used traditional preparations for ocular dosage forms, however they are not very effective as therapeutic systems. The needed amount of medicine is not immediately accessible for therapeutic action because it binds to the nearby extra orbital tissues after delivery because a considerable percentage of the topically administered drug is quickly diluted in the tear film and surplus fluid overflows over the lid edge. Given these losses, regular topical administration is required to keep medication levels appropriate. To reach therapeutic levels after systemic delivery of a medication for ocular illness, a high concentration of the medication must be present in the plasma. The duration of the medicine's activity can be noticeably extended and the frequency of drug administration can be decreased by adopting prolonged drug delivery.