Simultaneous determination of the concentration of mycophenolate mofetil and mycophenolic acid in plasma by HPLC

Objective: To establish an HPLC method for simultaneous determination of the concentrations of mycophenolate mofetil and mycophenolic acid in human plasma. Methods: The plasma sample was analyzed by HPLC on a Zorbax SB-C18 column(4.6 mm×250 mm,5 mm) with 0.3% aqueous triethylamine- acetonitrile(50:50) as a mobile phase at the detection wavelength of 215 nm, column temperature of 35 ℃ and flow velocity of 1.0 ml/min after the proteins were precipitated out by acetonitrile. Results: The standard curve was linear over the range of 0.25 ~10 mg/ml with r(MPA)=0.99976, r(MMF)=0.999 99. The recoveries of MPA and MMF were(87.38±2.97) % and(99.71±1.18) % and the limit of detection for MPA and MMF were 0.035 mg/ml and 0.070 mg/ml(S/N=3). Conclusion: This method is simple, sensitive, reproducible, and suitable for the monitoring of the concentrations of mycophenolic acid and mycophenolate mofetil in patients with organ transplantation and the pharmacokinetic study of mycophenolate mofetil.