Pharmacokinetic Study Of FNC In Rat By HPLC/MS Method

Nucleoside analogues can be used as important antiviral or anticancer agents. The established role of nucleoside analogues in the treatment of tumours trigger renewed interest in this class of antimetabolites. FNC,2’-deoxy-2’-β-fluoro-4’-azidocytidine, is a novel pyrimidine analogue. FNC is a highly potent and selective inhibitor of HIV and hepatitis B virus (HBV) replication. It also has been demonstrate that FNC inhibits cell proliferation, regulates the cell cycle and promotes apoptosis in a lot of human cancer cell lines in vivo. Furthermore, FNC has potent anti-tumor activity and low toxicity in xenograft mice bearing hepatocarcinoma, sarcoma and gastric carcinoma tumors.It promptes us do further research.Pharmacokinetics quantitative studys the dynamic laws of the absorption of drugs into the body through various means,distribution, metabolism and excretion process.It takes an important part in the objective evaluation of drug efficacy and toxicity, reasonable clinical therapy and design of the optimal dosage regimen and so on. FNC can be determined by ultraviolet spectrophotometry (UV) and high performance liquid chromatography (HPLC). However, those conventional detection methods can not quantify trace amount agents in biological samples due to the low dose and low concentration in plasma. In the present study, a rapid and sensitive high performance liquid chromatography-mass spectrometry (HPLC/MS) method was developed and validated to quantify FNC in rat plasma and applied to pharmacokinetic study.In this paper, there are several results with both scientific and practical significanc as below.The development of LC/MS method for the assay of FNC in rat plasma.A sensitive HPLC/MS method was established for the determination of FNC in rat plasma and fully validated. The calibration curves showed good linearity within the range2-2000ng-mL-1and LLOQ of this method was2ng·mL-1. The extraction recoveries of FNC were more than81.3%and the intra-day and inter-day RSD was less than13.11%, respectively. We have developed a simple, sensitive and rapid HPLC/MS method and the method was reliably applied to the pharmacokinetic studies of FNC in rats.Studies on pharmacokinetics of FNC in rats.A sensitive HPLC/MS method was used to the determination of FNC in rat plasma after a single oral administration of0.26,0.52and1.0mg/kg. The mean Cmax values are (222.958±57)、(370.922±86) and (488.982±43) ng·mL-1, respectively.the AUC0-∞values are (5208.051±325).(11242.902±507) and (19969.192±681) ng·h·mL-1, respectively. The mean Cmax, AUC0-∞values is good linearly related to dose (P<0.05) in the range0.26-1.0mg·Kg-1. There is no significant differences in other pharmacokinetic parameters among the there dose groups. The result showed that FNC in rats were best fitted to one-compartment model and meet the characteristics of linear pharmacokinetics within the dose range of0.26-1.0mg/kg.Excretion studies of FNC in rats.The concentration of FNC in urine and feces was determined by means of HPLC/MS method we developed. The results reveal the time-related changes of FNC in rat urine and feces. The results showed that the amounts excreted in urine and feces in the form of prototype FNC is10.34%.Plasma protein binding ratio of FNC in rats.In this study, equilibrium dialysis method was applied to plasma protein binding ratio at37℃. The HPLC/MS analysis method was applied to the determination of the FNC in dialysate and plasma. The results show that plasma protein binding ratio of FNC in rats was in range of19.3-28.9%, indicating that FNC widely distribute in vivo, which will help the drug quickly eliminate with better security.