[Manufacturing classification system for oral solid dosage forms of traditional Chinese medicines(â £): classification of hygroscopicity behaviors of capsules].

Hard capsules of traditional Chinese medicine(TCM) have different degrees of hygroscopicity, which affects the stability and efficacy of drugs. In this paper, 30 kinds of commercially available TCM capsules were used as the research object. The hygroscopicity curves of capsule contents, capsule shells, and capsules were tested respectively, and the first-order kinetic equation was used for fitting. The results show that during the 24 h hygroscopicity process, the capsule shell can reduce the weight gain caused by the hygroscopicity of the contents by 0.80%-53.0% and the hygroscopicity rate of the capsule contents by 1.74%-91.3%, indicating that the capsule shell has a strong delay effect on the hygroscopicity of the contents of the TCM capsules. Seven physical parameters of the contents of 30 kinds of TCM capsules were determined, and 14 prescription process-related parameters were sorted out. A partial least squares model for predicting the hygroscopicity rate of the contents of TCM capsules(with shell) for 24 h was established. It is found that the hygroscopicity rate of the capsule shell is positively correlated with the hygroscopicity of the contents of TCM capsules(with shell), suggesting that the capsule shell with a low hygroscopicity rate is helpful for moisture prevention. In addition, the pre-treatment process route of the preparation and the type of molding raw materials affect the hygroscopicity. A larger proportion of the extract in the capsule content and a smaller proportion of the fine powder of the decoction pieces indicate stronger hygroscopicity of the capsule content. The 24 h hygroscopicity rate of 15% was used as the classification node of hygroscopicity strength, and the hygroscopicity rate constant of 0.58 was used as the classification node of hygroscopicity speed. The classification system of hygroscopicity behaviors of TCM capsules was established: the varieties with strong and fast hygroscopicity accounted for about 6.67%, while those with strong and slow hygroscopicity accounted for about 33.3%; the varieties with weak and fast hygroscopicity accounted for about 26.7%, while those with weak and slow hygroscopicity accounted for about 33.3%. The classification system is helpful to quantify and compare the hygroscopicity behavior of different TCM capsules and provides a reference for the quality improvement, moisture prevention technologies, and material research of TCM capsules.

[Discrete element simulation study of mixing process of Guizhi Fuling Capsules: parameter calibration].

The mixing process is a critical link in the formation of oral solid preparations of traditional Chinese medicine. This paper took the extract powder of Guizhi Fuling Capsules and Paeonol powder as research objects. The angle of repose, loose packing density, and particle size of the two powders were measured to calibrate discrete element simulation parameters for the mixing process. The discrete element method was used to calibrate the simulated solid density of Paeonol powder and extract powder of Guizhi Fuling Capsules based on the Hertz-Mindlin with JKR V2 contact model and particle scaling. The Plackett-Burman experimental design was used to screen out the critical contact parameters that had a significant effect on the simulation of the angle of repose. The regression model between the critical contact parameters and the simulated angle of repose was established by the Box-Behnken experimental design, and the critical contact parameters of each powder were optimized based on the regression model. The best combination of critical contact parameters of the extract powder of Guizhi Fuling Capsules was found to be 0.51 for particle-particle static friction coefficient, 0.31 for particle-particle rolling friction coefficient, and 0.64 for particle-stainless steel static friction coefficient. For Paeonol powder, the best combination of critical contact parameters was 0.4 for particle-particle static friction coefficient and 0.19 for particle-particle rolling friction coefficient. The best combination of contact parameters between Paeonol powder and extract powder of Guizhi Fuling Capsules was 0.27 for collision recovery coefficient, 0.49 for static friction coefficient, and 0.38 for rolling friction coefficient. The verification results show that the relative error between the simulated value and the measured value of the angle of repose of the two single powders is less than 1%, while the relative error between the simulated value and the measured value of the angle of repose of the mixed powder with a mass ratio of 1∶1 is less than 4%. These research results provide reliable physical property simulation data for the mixed simulation experiment of extract powder of Guizhi Fuling Capsules and Paeonol powder.