Pulsatile Drug Delivery Systems for Chronopharmacology

Abstract

It is well known that many factors affecting the phamcokinetic parameters fluctuate dur-ing one day, because of the circadian rhythm. That is, blood flow rate, blood pressure, or hormone con-centration in blood varies depending on the time of day. For these 50 years, many studies have been done for many types of drugs about the relationship between the time of day at which the drug is administered and the therapeutic effects of the drug in the field of chronopharmacology. Then, it has been made clear that now “the flatter the better ”for the drug blood level is not desirable for a certain kind of drug, but“time-of-day”plays an increasing role in drug treatment. For such kind of drug therapy, a new drug delivery system, that is, pulsatile drug delivery system, is useful. In this review article, pulsatile drug delivery systems, such as a sigmoidal-drug release system, a time-controlled explosion system, PULSINCAP, a OROS delayed push pull system, will be introduced together with three-dimen-sional printing as a new pharmaceutical technology to prepare tablets.