Oleanolic acid nanosuspensions: preparation, in-vitro characterization and enhanced hepatoprotective effect

Oleanolic acid nanosuspensions: preparation, in-vitro characterization and enhanced hepatoprotective effect
February 2005
Yajun Chen1; Jie Liu1; Xiangliang Yang1; Xiaoling Zhao2; Huibi Xu2
Journal of Pharmacy and Pharmacology, February 2005, vol. 57, no. 2, pp. 259-264(6)
Pharmaceutical Press
Abstract:
Oleanolic acid is a naturally derived triterpene used clinically in the treatment of hepatitis in China, but its poor solubility often leads to poor bioavailability. In the present study, oleanolic acid nanosuspensions were prepared by the nanoprecipitation method and then systematically characterized. The average particle size of the obtained nanosuspensions was 284.9 nm, with a polydispersity index of 0.216. Transmission electron microscopy and atomic force microscopy showed that the drug existed as spherical or near-spherical nanoparticles in the nanosuspensions. Differential scanning calorimetry and X-ray diffraction studies indicated that oleanolic acid was present in an amorphous state in the lyophilized nanosuspensions. At 25?C, the saturation solubility of oleanolic acid was increased by about 6 times after nanoation (25.72 g mL?1 vs 4.37 g mL?1). In the in-vitro drug release experiments, the lyophilized nanosuspensions showed a faster drug dissolution rate than that of the coarse drug powder (approx. 90% vs 15% during the first 20 min), and nearly 95% of the oleanolic acid was released by 120 min. As evidenced by the lower serum alanine aminotransferase activity and liver malondiadehyde content, pre-treatment with oleanolic acid nanosuspensions significantly enhanced the hepatoprotective effect of oleanolic acid against carbon tetrachlorideinduced liver injury.
Language: Unknown
Document Type: Short communication
DOI: 10.1211/0022357055407
Affiliations: 1: College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China 2: Department of Chemistry, Huazhong University of Science and Technology, Wuhan, China
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