Preparation and in vitro release of Yangshen-paidu sustained-release tablet

To study the preparation process of the Yangshen-paidu sustained-release tablet, the preparation parameters were investigated by the single factor design method. The formulation was optimized to be 70% of extraction, 25% of HPMC, 4% of lactose, and 1% of magnesium stearate. The release rate of salvianolic acid B, tanshinone IIA, the total Anthraquinone of Radix et Rhizoma Rhei, Astragaloside A from the sustained-release tablet in vitro were measured according to Chinese Pharmacopeia(CP)2010 using Dissolution Testing Apparatus 1(basket method). The similarity factor was used to compare cumulative release curves. The cumulative curve of drug release data were fitted to zero order, first-order and Higuchi models to ascertain the kinetic modeling of drug release. The release mechanism was ascertained using Peppas equation. The similarity factors of the cumulative release curve of four ingredients mutually compared were all over 80, indicating that the release of four ingredients was similar. The cumulative release rate of four ingredients all fitted Higuchi models. The value of slopes of Peppas models of four ingredients was all more than 0. 45, indicating that the drug released by concurrent action of diffusion and matrix erode(non-fickian diffusion). This preparation technology of Yangshen-paidu sustained-release tablet is rational and practicable.