[Pharmacokinetics of genistein in urine of healthy volunteers].

In order to study the excretion of genistein (GEN) capsule, an estrogen drugs, in human, 30 healthy volunteers were selected and orally administered 50, 100, and 300 mg genistein in an parallel study. Genistein were determined in urine by LC-MS/MS and glucuronidated genistein (GENG) were indirectly determined with enzymatic hydrolysis in urine by LC-MS/MS, and the pharmacokinetic parameters were analyzed by DAS software (ver 2.0). The result showed that the concentrations of genistein in human urine were less than 1% of the GENG, and the cumulative excretion of GEN in 48 h were 0.037, 0.134, and 0.142 mg, separately, and the urinary excretion percentage were only 0.07%, 0.13%, and 0.05%, separately. But the cumulative excretion of GENG in 48 h was 5.3, 13.8, and 15.4 mg, separately, and the urinary excretion percentage were 10.6%, 13.8%, and 5.1%, separately, and the max urinary excretive rate was 0.4, 1.0, and 1.4 mg x h(-1), separately (tmax were 6 h). Studies showed that part of drug excreted through kidney in a form of GENG in human, and the cumulative urinary excretion and the maximum excretion rate of GENG showed a proportional increase conditioned with the dose in the range of 50-100 mg, but showed non-linear increase feature in 300 mg.