circadian rhythms

A Pulsatile drug delivery system delivers drug in rapid and burst manner within a short time after a lag time. There are many situations where drug is needed to be released immediately (after bursting the delaying film coat) at specific site. The aim of present work is to develop Pulsatile drug delivery of Tiotropium Bromide using press coating method. All the formulations have shown satisfactory results for various physicochemical parameters like hardness, friability, thickness, weight variation. Ethyl cellulose has predominant effect on the lag time, while also shows significant effect on drug release.  Press coated tablet shows a delayed release pattern. Among all the core tablet formulations T7 was selected based on drug release within a given period of time.  In-vitro release rate studies showed that the P3T7 was optimized based on less amount of drug release during lag time. Formulations P3T7 found to be stable at 45o C and 75% RH for a period of 6 months. FT-IR studies revealed that there was no interaction between Tiotropium bromide and the polymers. Keywords: Pulsatile drug delivery, circadian rhythms, Tiotropium Bromide, Lag time, Press coated tablets.

In order to design proper protocol for drug administration is consideration of circadian rhythm in drug pharmacokinetics. Several studies have concluded that all organisms including humans are highly organized by circadian rhythms. These changes in cycles will influence on physiological function thus, can influence on pharmacokinetics phases. Drug pharmacokinetic parameters can be changed according to the time of administration. The main objective of the chronopharmacokinetic study is to control the time of administration which among others can be responsible for variations of drug kinetics but also chronopharmacological effects observed with certain drugs. This article gives brief information regarding the changes of pharmacokinetics of the drug due to circadian rhythms.