Chronopharmaceutics: a promising drug delivery finding of the last two decades.

Pulsatile drug delivery system capable of releasing the drug after a predetermined lag period in pulsed or controlled release manner recently has drawn the attention of both academic and industrial research. Depending on the effective therapeutic application of the drug, a variety of design strategies have been formulated in the pursuit of pulsatile release. Circadian (24 hr cycle) dependency of various physiological and pathological functions is well established, thus, it becomes imperative to develop a drug delivery system to achieve release of drug at specific site and time.