chronopharmaceutical technologies.

Chronotherapeutics is the discipline concerned with the delivery of drugs according to inherent activities of a disease over a certain period of time. Chronotherapy can particularly benefit patients suffering from allergic rhinitis, rheumatoid arthritis and related disorders, asthma, cancer, cardiovascular diseases, and peptic ulcer disease. The biological systems require different amounts of drug at expected times within the circadian cycle. Many therapeutic agents are most effective when made available at constant rates, near the absorption sites or at the correct time of administration. Hence there exists a need for the development of such delivery system that matches the circadian rhythm. With the Chronotherapeutic drug delivery system this requirement can be fulfilled. As these systems deliver the right dose at right time at a specific site, they are gaining importance in the field of pharmaceutical technology. Hence a desired effect at the required time can be achieved by selecting a pulsatile system based on the pathological behavior. And also there will be a reduction in undesirable side effects due to the therapeutic action of the drug delivery system at the time of flare up of the disease symptoms. This review gives a comprehensive emphasis on circadian behavior of certain diseases, various approaches for the chronotherapeutic drug delivery systems and the existing technologies. Pulsatile drug delivery system can be classified as time controlled pulsatile release, stimuli induced and external stimuli pulsatile release systems etc. Still, a significant progress in achieving chronopharmaceutical drug delivery systems for the treatment of diseases in a pulsatile manner.