ABSTRACT
This chapter focuses on the physiological and anatomical aspects influencing ocular, nasal, pulmonary, and otic drug delivery. It explores the physicochemical properties that influence drug delivery through each route. The chapter explains the various strategies employed to optimize drug delivery through each route. It describes the production and packaging of commonly used dosage forms. The topical route of administration is used to treat diseases that affect the anterior segment of the eye such as keratitis, conjunctivitis, and glaucoma. Drug delivery vehicles used for topical administration include solutions, colloids, emulsions, suspensions, ointments, solid hydrophilic inserts, therapeutic contact lenses, rate-controlled release systems, and new delivery systems such as liposomes and particulates. Surfactants are used to solubilize and disperse the drug effectively. Drugs administered as ointments have better bioavailability than drops primarily owing to reduced dilution of drug with the tears, prolonged corneal contact time, and reduced drainage.
