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. Such systems are advantageous for drugs which have an extensive first pass metabolism, biological tolerance, needs targeting of locally absorbed / active drug to a specific site in intestine and are useful for the therapy for chronopharmacological needs. This manuscript portrays the important patents related to chronomodulated release system such as system with eroding, rupturing or soluble barrier coatings. In addition, recently developed chronotherapeutic dosage forms including tablets, capsules, pellets, beads implants, osmotic pump, liposome, thermoresponsive, inflammation stimuli sensitive, electrical stimuli sensitive, ultrasound stimuli responsive, magnetic stimuli responsive etc., are also conferred.