Impact of Particle Size on Density of Binary Powder Mixture of Chinese Medicine / 中国实验方剂学杂志

Objective:To investigate the influence of particle size on density of binary powder mixture of traditional Chinese medicine （TCM）， and to provide reference for formulation design of TCM preparations. Method:Three groups of binary powder mixtures with different particle size ratio （<italic>α</italic>） were constructed， namely Oroxyli Semen-microcrystalline cellulose PH102 （MCC PH102） （<italic>α</italic>=0.071 7）， Stellariae Radix-MCC PH200 （<italic>α</italic>=0.158 7） and Angelicae Sinensis Radix-MCC KG802 （<italic>α</italic>=0.840 6）. Binary powder mixtures with nine mass ratios （90∶10， 80∶20， 70∶30， 60∶40， 50∶50， 40∶60， 30∶70， 20∶80 and 10∶90） were prepared for each group， and 27 binary powder mixtures containing TCM were obtained. The particle size distribution， density and other parameters of six single materials and 27 binary powder mixtures were characterized. Based on the packing theory and multivariate analysis， the effects of particle size related parameters on the filling structure and density of the binary powder mixtures were elucidated. Result:The <italic>α</italic> of Angelicae Sinensis Radix-MCC KG802 binary mixture system was larger than the replacement rate （<italic>α</italic>_r=0.741 0）， and its density had a good linear relationship with the mass ratio， which conformed to the replacement mechanism. The <italic>α</italic> of Oroxyli Semen-MCC PH102 binary mixture system was smaller than the critical ratio （<italic>α</italic>_c=0.154 0）， and its density was nonlinear with the mass ratio of components， which conformed to the filling mechanism. The <italic>α</italic> of Stellariae Radix-MCC PH200 binary mixture system was between <italic>α</italic>_c and <italic>α</italic>_r， its density was affected by both of replacement mechanism and filling mechanism. Based on the partial least squares （PLS） model， the variable importance in the projection （VIP） analysis further proved that the mixing mass ratio （VIP value=1.62）， <italic>α</italic> （VIP value=1.13） and <italic>D</italic>₁₀ （the corresponding particle size when the particle size distribution accumulated to 10%， VIP value=1.06） were the key factors affecting the density of binary powder mixtures of TCM. Conclusion:In the binary powder mixtures of TCM， the linearity relationship between density and mass ratio is largely depended on particle size difference of components.

Mechanism of "unification of drugs and excipients" for Chinese medicine semi-extract based on powder compression behavior analysis / 中国中药杂志

In this paper, five representative Chinese herbal decoction pieces of Scutellariae Radix, Paeoniae Radix Alba, vinegar-processed Corydalis Rhizoma, Polygoni Multiflori Radix Praeparata and Lonicerae Japonicae Flos were selected to prepare the corresponding fine powder of pieces, extract powder, semi-extract powder and physical mixed powder. The physical properties of 20 kinds of powders, such as related parameters of particle size, density, stability and flowability, were evaluated comprehensively. The compression curves of powder porosity and tensile strength changing with pressure were plotted, and the Heckel equation and the Kawakita equation were used to describe the powder compression behavior. The results showed that compared with the fine powder of pieces, the compressibility of the semi-extract powder and the extract powder was significantly improved. Compared with the extract powder, the particle size and relative uniformity of the semi-extract powder were increased, indicating that the uniformity of the powder was improved. Besides, the semi-extract powder could reduce the hygroscopicity of the powder. Particularly, the semi-extract powder of Scutellariae Radix, Paeoniae Radix Alba and vinegar-processed Corydalis Rhizoma could maintain the porous structure of the tablet even under a high tableting pressure, which was beneficial to tablet disintegration. For some traditional Chinese medicines(such as Lonicerae Japonicae Flos), the semi-extract powder could reduce the viscosity, which avoided the sticking in the die compression. The semi-extract powder and the physical mixture powder prepared by the same Chinese herbal decoction pieces had similar physical properties and compression behaviors. Principal component analysis(PCA) was carried out on the 17 physical attributes and 5 compression parameters of the powder. It was found that the first principal component mainly reflected the differences among the material sources, while the second principal component could reflect the differences among fine powder of pieces, extract powder, semi-extract powder and physical mixed powder originating from the same Chinese herbal decoction pieces. In this paper, the mechanism of "unification of drugs and excipients" of Chinese medicine semi-extract powder was explained in terms of physical properties and compression behavior of powders, which provided reference for the formulation design and process development of Chinese medicine tablets.