Determination of Mycophenolic Acid in Kidney Transplantation Patients by HPLC

OBJECTIVE:To determine the plasma mycophenolic acid concentration by HPLC, and study the multidoses pharmacokinetics character of mycophenolic acid in Chinese kidney transplantation patients. METHODS: The samples were precipitated with acetonitrile before injection. Diamonsil C18 column was used. The mobile phase consisted of acetonitrile-10 mmol·L-1 KH2PO4 (5∶6) at a flow rate of 1.1 mL·min-1. The detection wavelength was 254 nm and the column temperature was 40 ℃. This method was used to determine the multidoses pharmacokinetics in 12 kidney transplantation patients. RESULTS: MPA was well-separated from internal standard in chromatography, and endogenous foreign substance in plasma had no interference on the determination. The liner range for MPA was 0.38～59.00 μg·mL-1,and the lowest detectable concentration of MPA was 0.38 μg·mL-1. The recovery rate stood at 89.32%～97.63%; Both intra-day and inter-day RSD were less than 8.00%. Significant individual difference was noted among the patients treated with MMF in pharmacokinetic results, which was in line with the literature. CONCLUSION: This method is accurate and simple and applicable for the pharmacokinetics study of mycophenolic acid.