Simultaneous determination of five triterpene acids in rat plasma by liquid chromatography-mass spectrometry and its application in pharmacokinetic study after oral administration of Folium Eriobotryae effective fraction.

Folium Eriobotryae effective fraction (FEA), the extract of Folium Eriobotryae, had been used as anti-hyperglycemia and anti-hyperlipemia medicine in China. A previous study indicated that euscaphic acid, maslinic acid, corosolic acid, oleanolic acid and ursolic acid, the five structurally similar triterpene acids (containing two groups of structural isomers), are the major components of FEA. In the present study, we developed a specific and reliable LC-MS method for simultaneous determination of the five triterpene acids in rat plasma, and further investigated their pharmacokinetic properties after oral administration of FEA. Following a simple sample preparation, chromatographic separation was achieved on a C18 column with a mobile phase composed of methanol-0.1% ammonium acetate (80:20, v/v). Quantification was achieved by monitoring the selected ions at m/z 487.6 for euscaphic acid, m/z 471.5 for maslinic acid and corosolic acid, m/z 455.5 for oleanolic acid and ursolic acid and m/z 469.5 for internal standard. The method was validated to be specific, accurate and precise over the concentration ranges of 10-3000 ng/mL with limits of detections of 5 ng/mL for the five triterpene acids. Finally, the method was successfully applied to the pharmacokinetic study of the five structurally similar triterpene acids in rats after oral administration of FEA.

[Preparation of solid dispersion of triterpenoid acids from Eriobotrya japonica leaf and study on their dissolution in vitro].

UNLABELLED: To prepare the solid dispersion of Eriobotrya japonica leaf triterpenoid acids(EJA) in order to enhance their dissolution characteristics in vitro. METHODS: Taking ursolic acid and oleanolic acid in vitro dissolution as an indicator, the influence of factors including different water-soluble carriers (PEG 6000, PVPk30 and P188) and the drug/carrier weight ratio for the preparation of solid dispersion were examined using single factor experiment. Differential scanning calorimetry (DSC) and X-ray diffraction (X-RD) were used to describe the characterization of solid dispersion. RESULTS: P188 was used as appropriate carrier for the preparation of solid dispersion and the drug/carrier weight ratio was 1:5. The X-RD and DSC showed EJA existed in the solid dispersion as the way of amorphous. The dissolution rate of EJA solid dispersion was significantly higher than physical mixture and EJA. CONCLUSION: The solid dispersion prepared with P188 can significantly increase the solubility and dissolution of EJA in vitro. This study provides the scientific evidence for further preparation of solid dispersion tablet.