Evaluation of fundamental and functional properties of natural plant product powders for direct compaction based on multivariate statistical analysis

Direct compaction (DC) is the preferred choice for tablet manufacturing; however, its application in natural plant product (NPP) tablets is still extremely immature. In this study, NPP powders prepared by three commonly used methods were evaluated on their suitability for DC. Extensive characterizations of their physical properties were performed. Multivariate statistical analysis was utilized to explore the influence of preparation technology on the properties of NPP powders and identify the dominating factors that influence their DC properties. The results demonstrated that (i) the 27 kinds of model NPP powders selected randomly in this study could to some degree represent most NPP powders used in actual production; (ii) ∼81.5% of the NPP powders exhibited both poor compactibility and flowability, and none of the NPP powders could be compacted into tablets via DC; (iii) the physical properties of NPP powders prepared by direct pulverization were significantly different from those of extracted ones, while there were no significant differences between the water and ethylalcohol extracted ones; and (iv) the DC properties of NPP powders could be improved through controlling some physical properties (e.g., density, particle size, morphology, and texture parameters) reasonably. Overall, this study comprehensively evaluated the current status and application of NPP powders in DC, and is significant in facilitating the development and modernization of NPPs through DC.