Effect of particle size on glycyrrhizic acid and liquiritin of Glycyrrhizae Radix et Rhizoma powder / 中草药

ABSTRACT

Objective: To study the effect of particle size on the contents and in vitro dissolution performances of the active ingredients (glycyrrhizic acid and liquiritin) in Glycyrrhizae Radix et Rhizoma powder, for the purpose of providing the appropriate particle size during the preparation of Glycyrrhizae Radix et Rhizoma powder. Methods: Seven Glycyrrhizae Radix et Rhizoma powder samples with different particle sizes were prepared in present work. Their micro-topography structures were characterized by particle size distribution and scanning electron microscopy (SEM). Thin-layer chromatography (TLC) was applied to qualitatively identify these samples. The contents and in vitro release performance of glycyrrhizic acid and liquiritin in the seven powder samples were analyzed by high performance liquid chromatography (HPLC). Results: The contents of glycyrrhizic acid and liquiritin increased with the decrease of particle sizes of the Glycyrrhizae Radix et Rhizoma powder samples. When the powder sizes were in the range of 300-900 μm, 105-300 μm or less than 105 μm, the contents of liquiritin and glycyrrhizic acid were stable. And 105-150 μm sample had good release performance in vitro. Conclusion: Controlling the particle size between 105 and 150 μm during the granulation process of preparing Glycyrrhizae Radix et Rhizoma powder would make the contents of liquiritin and glycyrrhizic acid in Glycyrrhizae Radix et Rhizoma powder higher, stable and have good in vitro release performance.