Drug Suspension Development for the Back of the Eye

With the FDA approval of triamcinolone acetonide suspensions for intravitreal injections, there is renewed interest in developing drug suspensions for sustained intravitreal delivery. For back of the eye drug delivery, suspensions can potentially be administered by various other routes including periocular, retrobulbar, and suprachoroidal routes. Suspension development, although new for back of the eye drug delivery, is not new, especially for topical, oral, and parenteral dosage forms. This chapter summarizes principles of suspension-based drug delivery and suspension formulation. Further, it highlights some unique issues related to the back of the eye suspension drug product development.