DESIGN AND CHARACTERIZATION OF COMPRESSION COATED CHRONOMODULATED SYSTEM OF NIFEDIPINE

Abstract

The main objective of the study was to formulate and evaluate compression coated chronomodulated system of Nifedipine for pulsatile release of the drug. The compression coated systems were prepared by direct compression technique using solid dispersion of nifedipine as core materials and viscoelastic polymers like PEG, HPMC K4M, HPMC K15M and HPMC K100M as coating material. The composition of polymers was varied to obtain different formulations of compression coated tablets with suitable lag time. Pre formulation and micromeritic properties were studied which were in compliance with the literatures limits. All the tablets (core and compression coated) were found uniform with respect to hardness (4.3-6.2 kg/cm²), thickness (3.9-4.44 mm), friability (0.32-

0.66 %), weight variation (0.84-1.56 %) and the drug content 90.02 - 94.60 %. Swelling studies revealed that compression coated tablets formulated with HPMC K4M swelled more than that of HPMC K15M and HPMC K100M. The mechanism of the drug release was Higuchi’s model release kinetics with r² value between 0.983-0.997. A graph devoid of any chemical interaction was observed between pure nifedipine and optimized formulation in FTIR and DSC studies. The present study concluded with the approach that can provide a useful means for programmable release of the drug with required lag time by employing different grades of HPMC polymers and direct compression technique.