OBJECTIVETo characterize the micromeritic properties and in vitro dissolution of common powder and micropowder of Glycyrrhizae radix and explore the application of micronization technique in preparation of the drug.

METHODSThe morphological and cellular characteristics of the 4 powders of Glycyrrhizae radix were examined microscopically, and their angle of repose and size distribution were measured. The content of licoflavone and liquirtin in the powders were determined by high-performance liquid chromatography and ultraviolet spectrophotometry, respectively. The dissolution rate of the active ingredients in the micropowder and common powder was studied by constant temperature mixing dissolution method.

RESULTSSignificant differences were observed between common powder and micropowder in particle characteristics and surface morphology. The dissolution rates and the concentrations of the corresponding ingredients in the micropowder were higher than the common powder.

CONCLUSIONMicronization is helpful for better utilization of the active components in Glycyrrhizae radix.