| |
| Z-Gly-Pro-doxorubicin (Z-GP-DOX), a prodrug of doxorubicin (DOX), has been proved in our previous study to be a good prodrug to achieve targeted delivery of DOX. Also, the pharmacokinetic study of Z-GP-DOX in rat plasma has been completed. In this paper, a simple, sensitive and specific HPLC-UV method for the determination of Z-GP-DOX in rat bile was established and validated. Following liquid-liquid extraction, chromatographic separation was accomplished by the mobile phase acetonitrile-0.1%trifluoroacetic acid (50:50, v/v) with a C18 chromatography column at a flow rate of 1 mL/min, room temperature and detection wavelength of 495 nm. The retention time of Z-GP-DOX was 6.6 min. A linear curve over the concentration range of 1-1200 μg/mL (r2 > 0.999) was established, and the LOD and LOQ for Z-GP-DOX were 0.5 and 1 μg/mL, respectively. Good precision and accuracy at concentrations of 2, 600 and 1000 μg/mL were obtained. The mean extraction recovery of Z-GP-DOX in bile was over 82.92% at the studied concentrations. The intra-day and inter-day relative standard deviations were generally less than 10%. This method was successfully applied to biliary excretion study in rats after intravenous administration of Z-GP-DOX. Bile samples were collected from bile duct cannulated rats after an intravenous bolus dose of 10 mg/kg or 20 mg/kg Z-GP-DOX, and the concentrations were measured by HPLC-UV. The results showed that the concentration of Z-GP-DOX in rat bile was much higher than that in plasma. After dosing, 28.14 ± 2.13% and 20.25 ± 3.59% of the dose were excreted into bile in unchanged form after a 12-h collection. The present study will contribute to supplementing the previous pharmacokinetic study of Z-GP-DOX in rats and will be helpful to improve the druggability study of Z-GP-DOX. |
|
| Keywords:Z-GP-DOX, HPLC-UV, rat bile, excretion |
|
