ABSTRACT
Excessive moisture absorption often occurs in Chinese material medica (CMM) preparations due to its raw material composition is easy to absorb moisture, the increases of water content easily weaken the stability of the preparations and increase the molding difficulty of the products at the same time. At present, the basic principle of moisture absorption can be explained by adsorption theory, theory of capillary condensation, and Fick diffusion theorem, combining a variety of evaluation indexes to judge the degree of moisture absorption, which can be as the basis for developing different moisture-proof technology of CMM preparations. The relevant literatures in recent years were reviewed in this paper, conbined with the widely recognized principle of moisture sorption, characterization method, and feasible moisture-proof technology, aiming to provide technical reference and implementation examples for the moisture-proof of CMM preparations.