[Advantage analysis of flow-through cell method in quality evaluation of Chinese patent medicine: a case study of Danshen Tablets].

To explore the quality consistency evaluation method for multi-component traditional Chinese medicine and establish a dissolution evaluation method suitable for the characteristics of multi-component Chinese patent medicine, this study discussed the characteristics and advantages of the flow-through cell method in the dissolution evaluation of Chinese patent medicine by comparing the impact of the small cup method and the flow-through cell method on the dissolution behavior of water-soluble and lipid-soluble major active components of Danshen Tablets. Dissolution tests were performed using the small cup method as described in the 2020 edition of the Chinese Pharmacopoeia and the newly introduced flow-through cell method(closed-loop method) with water solution containing 0.5% SDS as dissolution medium. Cumulative dissolution curves of the water-soluble component salvianolic acid B and the lipid-soluble component tanshinone Ⅱ_A in Danshen Tablets were plotted, and fitting and similarity analysis of the dissolution models was conducted to identify the characteristics and advantages of the flow-through cell method. For the small cup method, 150 mL of water containing 0.5% SDS was used as the dissolution medium, with a rotation speed of 75 r·min~(-1) and a temperature of(37±0.5) ℃, and 3 mL of samples were taken at 15, 30 min, 1, 2, and 4 h, with fresh dissolution medium added at the same temperature and volume. For the flow-through cell method, a closed-loop system was used. Danshen Tablets were placed in the flow-through cell with approximately 6.7 g of glass beads, and 150 mL of water containing 0.5% SDS was used as the dissolution medium. The flow rate was set at 20 mL·min~(-1), and the temperature and sampling were the same as the small cup method. The results showed that compared with the small cup method, the flow-through cell method had stronger discriminative power and higher sensitivity in distinguishing the dissolution behavior of the two components, and could better reflect the differences in formulation quality, especially for water-insoluble lipid-soluble components. Given that there were no essential differences in the in vitro release kinetics between the two methods, the flow-through cell method could not only replace the traditional small cup method but also better guide the formulation development and identify quality issues of formulations.