Formulation Optimization and Characterization of Carvedilol Hydrogel Matrix Sustained-release Tablets

OBJECTIVE To investigate the formulation process and characterization of carvedilol hydrogel matrix sustained-release tablets for slow release in vitro in 12 h. METHODS Two models of HPMC was used as hydrophilic matrix to prepare Carvedilol sustained-release tablets and the optimal formulation was screened by orthogonal test and validated. The release rate in vitro were investigated in four mediums. The existing state of sulfadiazine was identified by X-ray diffraction and IR spectroscopy. RESULTS The results showed that the optimal prescription was as follows:carvedilol of 7.5%, glycerin monostearate of 30%, HPMC K4M+E50 of 25%, the ratio of HPMC K4M to E50 was 2:1, lactose of 15%, the hardness of 3 kg. The release rate in vitro was the fastest within 12 h in the hydrochloric acid solution of pH 1.2, reaching over 90%, and the drug release was stable(RSD<1.5%, n=3). It was in line with Higuchi equation, which belonged to matrix erosion drug delivery system. Some crystals of the drug existed in the tablet, and there were no bonds between the main drug and excipients. CONCLUTION The preparation technology is feasible and exhibits perfect sustained-release characteristics in vitro in 12 h.