Hydrophillic and Hydrophobic Gelucires in the Design and Evaluation of Controlled Release Matrix Tablets of NifedipineAuthor(s): K. V. R. N. S. Ramesh, P. Ravishankar, V. Indira and A. Pavan Kumar
Controlled release matrix tablets of nifedipine are prepared by employing a new class of polymers called Gelucires. Two different types of gelucires are employed. Hydrophilic gelucire (Gelucire 53/14) is used to prepare solid dispersions of nifedipine to increase its dissolution rate. The solid dispersions were evaluated for drug content, solubility, dissolution rate and drug-polymer interaction. Nifedipine dispersed in hydrophilic gelucire is then converted into matrix tablet employing hydrophobic gelucire (43/01) and hydroxypropyl methyl cellulose. The prepared tablets were found to be of optimum hardness, uniform weight and acceptable friability. The drug release was found to be dependent on the ratio drug : gelucire in the solid dispersion and also on the type of release retarding polymer employed – gelucire (43/01) or hydroxypropyl methyl cellulose. Kinetics of the drug release data was evaluated out by employing the relevant equations of first order, zero order, Higuchi square root and Korsmeyer – Peppas. The drug release data suggested that the release of the drug is first order and that the drug release is diffusion controlled.