ABSTRACT
An implant is a single-unit drug delivery system that has been designed to deliver a drug moiety at a therapeutically desired rate, over a prolonged period of time. Such systems are most commonly used for
sustained parenteral administration, including ocular and subcutaneous drug delivery. This chapter focuses on such implant systems and the mechanisms of rate control which form an intrinsic component of implantable systems. As these rate control mechanisms are applicable to many other drug delivery systems, this chapter also serves as a general introduction to the methods of rate control which are achievable using advanced drug delivery and targeting strategies.
