ABSTRACT
This study aims to construct a dynamic two-dimensional characterization technique for the hygroscopicity of traditional Chinese medicine extracts and investigate the effect of material properties of powders on hygroscopicity. The dynamic hygroscopicity-time curves of the powders were measured at 25 ℃ and 75% humidity, and the semi-equilibrium hygroscopicity time (t1/2) and equilibrium hygroscopicity (F∞) were derived as two-dimensional evaluation indicators. Finally, the correlation between the material properties and the hygroscopic behavior was analyzed by principal component analysis (PCA) and partial least squares analysis (PLS). The results showed that the dynamic two-dimensional characterization system of hygroscopicity constructed with 1/t1/2 = 0.1 h-1 and F∞ = 15% as the center can classify the hygroscopic behavior of traditional Chinese medicine extracts into four categories: fast hygroscopicity with strong hygroscopicity, slow hygroscopicity with strong hygroscopicity, fast hygroscopicity with weak hygroscopicity and slow hygroscopicity with weak hygroscopicity. The moisture absorption was negatively correlated with D50, D90, ρb and ρt; the moisture absorption rate was negatively correlated with D10, D50, D90, ρb, ρt, and positively correlated with moisture content. The hygroscopicity dynamic two-dimensional characterization indicators of Chinese medicine extracts (CMEs) constructed in this study matched with the physical properties. The method of dynamic multi-dimensional characterization technology is feasible and scientific, and the idea has strong promotional value.
ABSTRACT
This study was designed to investigate the correlations of the spatial structure properties of Chinese medicinal extracts with hygroscopicity and the anti-hygroscopic techniques. With Poria extract used as the model drug, pregelatinised starch and microcrystalline cellulose at different ratios were added into Poria fluid extract for preparing powder particles with diverse spatial structures using different drying processes. Then, their hygroscopic behaviours were characterized by equilibrium hygroscopicity(F~∞) and semi-hygroscopic time(t_(1/2)). The correlations of the hygroscopicity of each powder with the spatial structure properties such as particle size(D_(90)), porosity(ε), true density(ρ_t), and surface element distribution were analyzed using partial least-squares method. The F~∞ and t_(1/2) values of Poria extract prepared by three drying methods were sorted in a descending order as follows: F~∞(spray drying>drying at ordinary pressure>drying at reduced pressure); t_(1/2)(drying at reduced pressure>drying at ordinary pressure>spray drying). The powder obtained by spray drying showed a spherical structure with the smallest particle size and intra-particle ε but relatively stronger hygroscopicity. The large-scale surface element enrichment of the powders dried by reduced pressure effectively reduced their hygroscopicity. F~∞ and t_(1/2) were negatively correlated with ε but positively with D_(90), and the interactive influence of each spatial structural properties was not significant. There existed a correlation between the spatial structure of the powder particles of Chinese medicine extracts and their hygroscopicity, and the hygroscopicity could be improved by designing the spatial structure. This study has provided some practical basis for developing the moisture-proof technology of Chinese medicinal preparations.
Subject(s)
China , Particle Size , Plant Extracts , Powders , Technology , WettabilityABSTRACT
At present, the modernization of Chinese medicine preparations (CMPs) is still a challenging task. The 3 typical Chinese medicine materials (CMMs) used for preparing CMPs are the powders, extracts, and components of Chinese medicine and their properties of CMMs are important for designing CMPs. Basing on our long term research, we have established a property system for CMMs according to the state of CMMs under an exactly condition and according to the interaction characteristics between substances. The property system could be divided into 5 categories: material composition, spatial structure, body property, surface property, physicochemical properties, and they could also be divided into 18 subcategories. Furthermore, we also established the corresponding index and characterization system, where the 61 indexes and characterization techniques were systematically summarized. At last, we hope that the article will promote the modernization of CMPs.