Ocular Drug Delivery: Impact of In Vitro Cell Culture Models

The physiological characteristics make effective drug delivery very challenging. Various structures such as the cornea, conjunctival epithelium, blood-retinal barrier (BRB), and the retinal epithelium block or severely reduce the concentration of drugs that can reach particular locations in the eye. Because of this, in vitro models that can effectively model each of these barriers are highly desirable. Such in vitro modeling allows researchers to minimize the use of animal studies, as drug delivery experiments require frequent euthanization. As a substitute for animal experiments, various types of in vitro models have been developed that are made up of primary cell cultures or immortalized cell lines. These cell lines allow for the detailed study of the individual processes that determine the ability of drugs and drug delivery systems to reach their desired locations in therapeutic concentrations. This chapter discusses various examples of such cell lines and their applicability in various drug delivery studies.