中药水提取有效成分转移率低的问题分析

分析《中国药典》2010年版一部成方制剂和单味制剂中水提取工艺存在的问题,为《中国药典》的修订和中成药产业化提取提供参考.通过查阅国内外文献,结合《中国药典》2010年版一部成方制剂和单味制剂的提取工艺,分析提取工艺的4个基本阶段,阐明水提取工艺有效成分转移率低的问题.结果表明水提取工艺的任何一个阶段都会引起中药有效成分转移率降低,并直接影响疗效.在浸润与渗透阶段,一方面是水的渗透性较差,另一方面是药材含油量较高,大分子量高的药材以水作为溶剂难以浸润;在解吸与溶解阶段,溶解度较小的非极性、中极性成分与水亲和力较小,难以溶解完全;在扩散阶段,中药中的大分子成分由于相对分子质量较大,难以穿透细胞屏障扩散至溶媒中,造成扩散困难;在置换阶段,物质在相互交换的过程中,大分子共存物也会影响其他物质在细胞生物膜两侧的交换.有效成分转移率低是目前中成药水提取存在的共性问题,阻碍了中成药的产业化发展,应引起业内人士的关注和重视并早日寻求出提取工艺研究的新思路.

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

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.