ABSTRACT:
Pulsatile drug delivery systems (PDDS) are getting prime importance in the field of pharmaceutical sciences as these systems deliver the right dose at specific time at a specific site. In pulsatile drug delivery system the drug is released rapidly after a well defined lag-time. It could be advantageous for many drugs or conditions. A pulse has to be designed in such a way that a complete and rapid drug release is achieved after the lag time so as to match body’s circadian rhythms with the release of drug which increases the efficacy and safety of drugs by proportioning their peak plasma concentrations during the 24 hours in synchrony with biological rhythm. Pulsatile release systems can be classified in multiple-pulse and single-pulse systems. This article mainly focus on different approaches for colon specificity, various techniques available for the pulsatile delivery like pH dependent systems, time dependent systems, etc. A popular class of single-pulse systems is that of rupturable dosage forms. Advantages of the pulsatile drug delivery system are reduced dose frequency; reduce side effects, drug targeting to specific site like colon and many more. Now in market varies technologies of pulsatile drug delivery system like Pulsincap, Diffucaps etc. are launched by pharmaceutical companies.