A Novel Kinetic Model for Dissolution of Herbal Medicine

To establish a novel kinetic model for phytochemical constituent dissolution, including comparison of results of open and closed dissolution systems, Buyanghuanwu decoction (BYHWD), a traditional Chinese herbal medicine formula, was selected as our experiment subject. The establishment of a kinetic model was based on the theory of Fick's Rule and Noyes-Whitney equation. By fitting the kinetic parameters of dissolution models, calculating the inherent parameters and the dissolution efficiency in herbal medicine, the results can be used to evaluate phytochemical constituent dissolution. In this study, laetrile, ferulic acid, and paeoniflorin were considered as three marker compounds, which were determined by high-performance liquid chromatography (HPLC). The dissolution processes and results with BYHWD were described and evaluated by these kinetics models. The results showed that the AUC (area under the curve) for open system was 9.21. times higher than the closed system. Decomposition power (D-p) in the open system was 1.505 times higher than the closed system, and the calculated transfer power (T-p) for the open system was 1.23 times higher than the closed system.