Distribution in tissue and excretion in urine and feces of swertisin after intravenous administration to rats

Swertisin contents in rat urine, feces and tissues were determined by reversed-phase high-performance liquid chromatography (RP-HPLC) method. Chromatographic separations were performed on a C ₁₈ column with acetonitrile-water (23:77, v/v) as the mobile phase. The calibration curves were linear over the ranges of 0.175-35.0 μg/mL for rat urine, 0.5-60.0 μg/mL for rat feces, and 0.014 to 53.0 μg/mL for all tissues. The inter- and intra-day precisions and accuracy for all measured samples were satisfactory. The fully validated method was applied for tissue distribution and excretion of swertisin in rat urine and bile after intravenous administration. The maximum level of swertisin was found in kidney, which reached 83.87± 6.36 μg/g. In rat heart, swertisin was hardly detected under used experimental conditions. Swetisin level in liver, kidney, stomach, smooth muscle and skeletal muscle continued to decrease from 5 to 60 min. Swertisin showed increasing tendency in intestine, spleen and testis tissues at scheduled time points. Detectable swertisin was found in brain and lung tissue. Totally 11.9% swertisin dose was cumulatively excreted from urine in 60 h after intravenous administration. There was small amount of swertisin in rat feces and the cumulative excretion level reached 4.59% of intravenous dose in 60 h.