DESIGN AND CHARACTERIZATION OF COMPRESSION COATED CHRONOMODULATED SYSTEM OF NIFEDIPINE

Th e m ain objective of the study was to formulate and evaluate com press ion 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 nifed ipine as core mater ials and viscoelastic polymers like PEG, HPMC K4M, HPMC K15M and HPMC K100M a s coating material . The composition of polymers was varied to obtain d ifferent formulations of compression coated tablets with suitable lag time . Pre formulatio n and micromeritic properties were studied which were in co mpliance with the literatures limits . All the tablet s (core and compression coated) were found uniform with respect to hardness (4.3 - 6.2 kg/cm 2 ), 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 r elease was Higuchi ’s mode l release kinetics with r 2 value between 0.983 - 0.997. A graph devoid of any chemical int eraction was observed between pure n ifedipine and optimized formulation in FTIR and DSC s tudies. 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. Keyword: Nifedipine , HPMC , direct compression , Lag time, pulsatile release