[The factors influencing metoprolol succinate release from hydroxypropyl methylcellulose matrix tablet].

The hydroxypropyl methylcellulose (HPMC) matrix tablet containing metoprolol succinate (MS) as a model drug was obtained by wet method compression tablet. The effects of the amount and viscosity of HPMC, the preparation method, compressing pressure, the amount of ethycellulose (EC), the pH of dissolution medium and the speed of basket rotation on the drug release from the matrix tablets were evaluated. The results showed that the release rate of metoprolol succinate from HPMC matrix tablets followed Higuchi equation. The release mechanism was in line with the synthetical effect of diffusion and corrosion. Drug release was influenced by the amount and viscosity of HPMC, the amount of EC in matrices, the preparation method and compressing pressure, etc. Drug release was not influenced by the pH of dissolution medium used, and not by the speed of basket rotation, either.