Pulsatile drug delivery system

In the recent years the pulsatile drug release systems are gaining growing interest. The pulsatile drug release where the drug is rapidly released after the well defined lag-time could be advantageous for many drugs or therapies. The sustained & controlled release devices are not applicable in some of the cases like the time-programmed administration of the hormones & many drugs. The living systems are the predictable dynamic resonating systems which require different amounts of drug at the expected times within the circadian cycle. The pulsatile drug delivery system has fulfilled this requirement. This system is such a system where the drug is released suddenly after the well-defined lag time or the time gap according to the circadian rhythm of the disease states. No drug is released from the device within this lag time. This method is good for the drugs with the extensive first pass metabolism & targeted to the specific site in the intestinal tract. The current article focuses on the necessities of pdds, diseases requiring PDDS, classification of pulsatile drug delivery system, current situation and future scope& marketed technologies of pulsatile drug delivery system.

The objective of present investigation was to prepare a chrono-modulated drug delivery system for Naproxen sodium to meet chrono pharmacological needs of Arthritis. Press coated tablets is a novel oral pulsatile release drug delivery system in which  the drug is released after certain period of lag time generally due to the erosion of barrier layers. Tablets were prepared by direct compression method. The core tablet was formulated using super-disintegrants like sodium starch glycolate, crosspovidone and crosscarmellose sodium. Whereas, the barrier layer contains polymers like carrageenan gum (Viscarin GP-209), xanthan gum in different concentrations and lactose anhydrous as channeling agent for maintaining lag time. The drug-excipient compatibility was confirmed by using FTIR, predicted that there was no chemical interactions between the drug and excipients. The tablets prepared were evaluated for micromeritic properties. In-vitro drug release studies were carried out using pH 1.2 buffer for initial 2hrs and in pH 7.4 phosphate buffer for remaining 10hrs. All the formulations followed first order release kinetics. From the obtained results it was found that the F9 formulation of immediate release core tablets (10% of Crosspovidone) showed optimized in vitro disintegration time and wetting time respectively. In case of press-coated tablets PCT 8 formulation with hydrophilic polymers 19.2% carrageenan gum, 19.2% xanthan gum and 7.69% lactose anhydrous as channeling agent has shown 6hrs of lag time is considered as optimum formulation and is successful in resisting different RPM pressures for designing into pulsatile delivery for treatment of Arthritis.