Abstract
Chronotherapeutics refers to a treatment method in which in vivo drug availability is timed to match rhythms of disease in order to optimize therapeutic outcomes and minimize side effects. It is also known as pulsatile drug delivery system and it focuses on the release of a drug at particular time and at a particular site in order to maintain constant blood levels of a particular drug. The specific time that patients take their medication is very important as it has significant impact on success of treatment. If symptoms of a disease display circadian variation, drug release should also vary over time. Drug pharmacokinetics can also be time dependent; therefore, variations both in a disease state and in drug plasma concentration need to be taken into consideration in developing drug delivery systems intended for the treatment of disease with adequate dose at appropriate time. These drug delivery systems are designed to release the drug within a short period of time, immediately after a predetermined lag time. Chronotropic systems are promising drug delivery systems in asthma, peptic-ulcer ,cardiovascular diseases, arthritis, attention-deficit syndrome in children and hypercholestremia e.t.c. Approaches like capsular systems, systems with different type of barrier coatings, stimuli sensitive pulsatile systems and externally regulated systems are summarized in this article. This article mainly focuses on diseases requiring chronotropic systems, approaches to design them, recent technologies for chronotherapy.
