ABSTRACT
Objective To establish a RP-HPLC method for determining the concentration of prulifloxacin active metabolite in human plasma and urine.Methods The supernatant obtained by centrifugation after the sample was precipitated with methanol- acetonitrile (1:1) was chromatographically separated on a Diamonsil C_(18)(250 mm?4.6 mm,5?m) using a mobile phase con- sisting of acetonitrile and 0.05 mol/L potassium dihydrogen phosphate (pH2.2) containing 1% tetrabutylammonium bromide. The solutions of 20:80 (V/V) and 12:88 (V/V) at a flow rate of 1.0 mL/min and 1.6 mL/min were used for plasma and u- rine, respectively.Then the samples were assayed at wavelength of Ex 280 nm and Em 425 nm.Results The linear range for prulifloxacin active metabolite in plasma and urine were 0.005-5 mg/L (r=0.9999) and 0.05-5 mg/L(r=0.9999)with a low- er limit of quantitation of 0.002 mg/L and 0.01 rag/L, respectively.In plasma, the relative recovery ranged from 100.64% to 101.00% at the concentration of 5.00, 0.50 and 0.05 mg/L and within-day and between-day precisions were less than 2.5% and 4.6% respectively.Meanwhile, the relative recovery ranged from 97.20% to 100.20% at the concentration of 2.50, 0.50 and 0.10 mg/L in urine.The within-day and between-day precisions were lower than 1.3% and 4.3%, respectively.The method had been successfully used for the pharmacokinetic studies of a prulifloxacin formulation after oral administration to healthy volunteers.Conclusions The present method is simple, rapid, accurate, reproducible and suitable for the pharmacoki- netic study of prulifloxacin in humans.
ABSTRACT
<p><b>OBJECTIVE</b>To analyze the correlation between drug exposure (AUC0-4) and blood concentration of different sample points during Neoral absorption phase in Chinese adult liver transplant recipients, and to evaluate the possibility of using post-dose 2 hour level (C2) as a surrogate marker of AUC0-4 for the therapeutic drug monitoring (TDM) of Neoral.</p><p><b>METHODS</b>Neoral levels at 0, 1, 2, 3, and 4 hours (C1, C2, C3, C4) after morning dose of 22 de novo Chinese adult liver transplant recipients were monitored during different posttransplant periods. Liner regression was used to analyze the correlation between CsA concentration at different time points and the AUC0-4.</p><p><b>RESULTS</b>The best correlation was found at C2, while the correlation of C0 was the lowest. During following-up, the correlation between C2 and AUC0-4 was very stable.</p><p><b>CONCLUSION</b>C2 had the best correlation with drug exposure. This correlation is very stable. C2 may be used as a good surrogate marker of AUC0-4 for the TDM of Neoral.</p>