Excretion stereoselectivity of triticonazole in rat urine and faeces

The purpose of this study was to study the excretion stereoselectivity of triticonazole enantiomers in rat urine and faeces. Six male Sprague-Dawley (SD) rats were administrated 50 mg/kg rac-triticonazole. Rats urine and faeces were separately and quantitatively collected at the following intervals: 0-3, 3-6, 6-9, 9-12, 12-24, 24-36 and 36-48 h. The faeces samples were homogenized in an aqueous solution containing 0.2% DMSO at the ratio of 1 g: 40 mL. An aliquot of 100 μL rats urine or faeces homogenate was spiked and mixed with 6.0 μL of 1.00 μg/mL flusilazole as an internal standard. The triticonazole enantiomers in urine and faeces were determined by using an HPLC/MS-MS after samples preparation. The excreted amounts of enantiomers in the urine showed a significant difference (P < 0.05) except for 3-6 h. The cumulative excretion rate (Xu_0→24) in urine was 26.43 ± 0.08% and 37.58 ± 0.11% for R-(-)- and S-(+)-triticonazole, respectively, indicating high enantioselectivity (P < 0.001). The cumulative excretion rate (Xu_0→72) in faeces was 6.93 ± 0.03% and 6.77 ± 0.03% for R-(-)- and S-(+)-triticonazole, respectively, without a difference. The results showed that the total cumulative percentage of triticonazole enantiomers accounted for in urine and faeces was 64.00 ± 0.13% and 13.70 ± 0.32%, the urinary excretion of R-(-)- and S-(+)-triticonazole were significantly different and S-(+)-triticonazole was preferentially excreted. However, the faecal excretion of the enantiomers showed no difference.