Controlled drug delivery [16] can be defined as delivery of the drug at a predetermined rate and/or to a
location according to the needs of the body and disease states for a definite time period. Controlled
release drug administration means not only the prolongation of the duration of drug delivery, similar to
the objective in sustained release and prolonged release, but the term also implies the predictability and
reproducibility of drug release kinetics. Oral controlled release drug delivery system is one that provides
continuous oral delivery of drugs at predictable and reproducible kinetics for a pre-determined period
throughout the course of GI transit.