ABSTRACT
For patients, the oral route represents the easiest and most practical method of taking a drug; it is also usually the safest and least expensive route available. Commercially, as discussed in Chapter 21, the oral drug delivery market comprises the largest slice of the overall drug delivery market. However, the oral route is not without signicant challenges. We begin our discussion with a consideration of the anatomy and physiology of the gastrointestinal (GI) tract, the implications therein for successful oral drug delivery, and the factors that must be taken into account in designing appropriate oral drug delivery systems (DDS). This is followed by a discussion on oral controlled-release (CR) technology, beginning with the most widely used and successful technology in oral CR: the hydrophilic matrix tablet. Dissolution-and/or diffusion-controlled matrix and reservoir constructs, osmoticcontrolled devices, and microelectronic devices are also described. Drug targeting is discussed with respect to regional targeting within the GI tract: via gastroretention in the stomach and drug targeting to the small intestine (SI) and colon, respectively.
