Determination of the blood concentration of cyclosporine A alone and in combination with fluconazole by HPLC/MS

YI Lin-gao; WU Ming-chai; HUANG Peng; CHEN Xiao-hai; LU Ri-ming

Abstract：Objective:To establish a mass spectrometry method for determination of blood concentration of cyclosporine A (CsA), and determine the blood concentration of cyclosporine A alone and in combination with lfuconazole.Methods:The blood concentration of cyclosporine A in rats was detected and compared when cyclosporine alone and combined with lfuconazole by using liquid chromatography-mass spectrometry. Chromatographic column Agilent Zorbax SB-C18 was used. Column temperature was 50℃. Mobile phase was acetonitrile-0.1% formic acid. Flow rate was 0.5 mL·min-1. Mass spectrometry condition was as follows: ESI (electrospray ion source) was used, positive ion detection was used, atomizing gas pressure was set to 20 psi.Results:The linear relationship of CsA was good in the range of 100 – 20 000 ng·mL-1 (r = 0.999 6). Intra-day RSD and inter-day RSD were less than 5%. The average extraction recovery was 90%. The average blood trough concentration of CsA when CsA combined with lfuconazole was higher (by 178.0%) than just cyclosporine alone in ifve days, and the peak concentration in combined utilization was higher (by 161.3%) than that of alone use.Conclusion: The method is simple, specific, accurate and high sensitivity, which can also be used for the determination of CsA blood concentration and pharmacokinetics study. Patients who are using CsA and lfuconazole will obviously have high blood concentrations of CsA, should reduce the dosage of CsA, and monitor the blood concentration.