FORMULATION AND EVALUATION OF CHRONOMODULATED COLONIC DRUG DELIVERY OF NIFIDIPINE

The pulsatile drug delivery works upon the system that releases active pharmaceutical ingredient completely and rapidly after a desired lag time. This type of approach was advantageous for: Drugswith extensive first pass metabolism and biological tolerance. Locally absorbed or acting drugs to a specific site in the intestinal tract (e.g. colon). Adaptation of therapy according to chronopharmacological needs. The pH-dependent polymers in pulsatile drug delivery were insoluble at low pH levels but with increase in pH solubility of polymer increases. The objective of present study was to develop a pulsatile compression coated tablet. The system was developed into two steps: Firstly core tablet was prepared containing Nifidipine as API. Secondly core tablet was coated with polymer blend of Eudragit S100and Eudragit L100. The lag time was the time in which less than 10% of drug was released. From in vitro release study we had concluded that drug release at pH 6.8 was inversely proportional to the amount of polymer Eudragit L100, which might be due to pH-dependent solubility of Eudragit S 100 at pH above 7. We also concluded that compression coated tablet containing higher proportion of Eudragit L 100 follows Higuchi kinetic model, whereas First order kinetic model was followed by compression coated tablet containing higher proportion of Eudragit S100.