ABSTRACT

INTRODUCTION Ophthalmic formulations are those that are intended for treating conditions of the eye; they may be intended to alleviate the signs or symptoms associated with a certain disease state, to provide relief from minor discomfort and irritation, or for treatment of the cause of a disease of the eye itself. In general, the best way to treat ophthalmic diseases is with a local treatment such as a topically administered eye drop. However, the biological design of the eye is optimized to keep the surface of the eye clear of all foreign substances and to provide a substantial barrier to transport of materials into or out of the eye. As a result, ophthalmic drug delivery presents a significant technical challenge. The ophthalmic formulator, therefore, must begin with a good understanding of the physiology of the eye and understand what ophthalmic drug delivery possibilities are available. The formulator must also understand the nature of the drug substance that needs to be delivered to the eye and its limitations. The ultimate job of the ophthalmic formulator is to discover the best way to bring the drug and the eye together in a fashion that will provide the optimal benefit to the patient.