Quality Control Studies on ZuoJin Sustained-Release Tablets

ZuoJin sustained-release tablets (ZJSRT), which consist of Rhizoma coptidis–Evodia rutaecarpa powder (6:1, g/g), have been widely used for a long time as a treatment of gastrointestinal disorders in China. Because ZJSRT is a kind of Chinese medicine prescription (CMP), it comprises many components, which makes the quality control studies more difficult. The main aim of this paper was to evaluate the release of four alkaloids using kinetic models and to assess the dissolution behaviors of ZJSRT using total quantum statistical moment (TQSM). The release data generated during in vitro release studies were fitted to zero-order, first-order, Higuchi, Hill, Weibull, and Michaelis–Menten models. The dissolution behavior data were obtained by calculating the TQSM parameters. The release kinetics of ZJSRT from most formulations follow a classical Fickian diffusion mechanism but do not follow an empirical model. The data from the TQSM parameters demonstrate that all components in ZJSRT released at nearly the same ratio and the same time. Therefore, the study should contribute to the quality control for CMP such as ZJSRT.