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

ABSTRACT

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.