Analysis on low transfer rate of active constituents by water extracting from Chinese materia medica / 中草药

ABSTRACT

To point out the current problems on the water extraction process in the preparation of patent medicine or single medicine recorded in Chinese Pharmacopoeia 2010, and to provide the references for the next Chinese Pharmacopoeia and the water extraction technology of traditional Chinese patent medicine (CPM) industry. According to Chinese Pharmacopoeia 2010 and literature at home and abroad, the four basic stages of extraction were analyzed and the problems on the low transfer rate of active constituents by water extraction were discussed. In the four stages of water extraction process, any stage that was limited led to the low transfer rate of active constituents or even influenced the drug's efficacy directly. Not only the poor permeability of water, but also the high oil and macromolecular components in Chinese herbs could limit the infiltration with water as solvent. In desorption and dissolution stages, the poor solubility of nonpolar and medium polarity components with a low affinity for water was difficult to dissolve completely. In diffusion stage, the active constituents in Chinese materia medica were difficult to penetrate the cellular barrier and spread to the water due to the larger molecular weight. In substitution stage, coexisting macromolecular substances affect the other mass exchanges on both sides of cell biological membrane in the process of material mutual exchanges. It is the common problem that water extraction ratio of CPM is low. It is also the urgent problem of Chinese Pharmacopoeia to be solved, or it will definitely hinder the development of industrial CPM. Insiders should pay more attention to this problem and take new ideas to solve it.