Chronopharmaceutics: as a clinically relevant drug delivery system

Current research in the field of drug delivery devices, by which pulsatile release is achieved, has been intensified. In this article, an attempt has been made to discuss several types of drug delivery systems that show pulsatile drug delivery characteristics. As found frequently in the living body, many vital functions are regulated by pulsed or transient release of bioactive substances at a specific site and time. Thus it is important to develop new drug delivery devices to achieve pulsed delivery of a certain amount of drugs in order to mimic the function of the living systems, while minimizing undesired side-effects. Pulsatile delivery, which is meant as the liberation of drugs following programmed lag phases, has drawn increasing interest, especially in view of emerging chronotherapeutic approaches. This review article is an attempt to discuss various design strategies, chiefly including reservoir, capsular, and osmotic formulations, and drug delivery systems which cause the pulsed or triggered release of bioactive compounds induced due to certain stimuli like thermal, electrical, and magnetic.