ABSTRACT
This chapter presents a historical overview of the eld of controlled drug delivery, describing how it grew in the past 60 years from a very small eld, to the immense size and importance it represents today for human and animal health. This chapter also highlights many of the people who were involved in the conception and design of the key controlled drug delivery systems (DDS), as well as details about the compositions of the materials used. We begin by considering some of the earliest drug delivery formulations, followed by a discussion of some of the key technologies in the history of controlled drug delivery. It should be noted at the outset that in the early days of controlled drug delivery, the term “controlled release” tended to refer specically to zero-order drug release obtained via a rate-controlling membrane (RCM), whereas the terms “sustained release” and “extended release” referred to the prolonged drug release obtainable using other DDS such as the oral Spansules® and bioerodible implants. With the passage of time, however, the delineation of these denitions has blurred. Currently, all these terms are used interchangeably, and the term “sustained release” is widely used.
