Abstract

The new methods for making polymeric systems for the controlled release of rifampicin drug is described. This method is very simple, it consists of mixing drug and polymer powder (ethylene-vinyl acetate copolymer) and compressed at room temperature. The compressed fluffy matrices were kept at 60°, 70° and 80° for 1½, 3 and 4½ h for sintering. The sintering tablets were charcterised for their physical parameters and conducted in vitro dissolution tests. The sintering time markedly affected the drug release properties of EVA (ethylene vinyl acetate copolymer) matrices. It is notable that the release rate of rifampicin from EVA matrices was inversely related to the time of sintering. This may be due to the increase in the extent and firmness of sintering which compacts the mass further so that the drug release is affected. The cumulative percent of rifampicin release decreased as the sintering temperature was increased, for all formulations. The drug release follows diffusive mechanism with first-order release kinetics.