Validation of a high-performance liquid chromatography method for the measurement of mycophenolic acid and its glucuronide metabolites in plasma

Intra-assay precision and accuracy of calibrators were determined for MPA at 0.5 and 20 mg/L, MPAGe at 5 and 200 mg/L, and MPAGa at 2.5 and 100 mg/L and showed coefficients of variation of less than 5.0% and biases of less than 14.0%. Inter-assay precision and accuracy of quality control samples were determined for MPA at 2 and 15 mg/L, MPAGe at 20 and 150 mg/L and showed CVs of less than 5.0% and biases of less than 14%. The lower limit of quantitation of the method was determined for MPA at 0.25 mg/L, MPAGe at 0.5 mg/L, and MPAGa at 0.25 mg/L and showed CVs of less than 19% and biases of less than 20%. This method, compared to the EMIT® 2000 MPA immunoassay, showed a linear regression analysis relationship of EMIT = 0.973 HPLC + 0.55 (r2 = 0.851), and was determined to be suitable for therapeutic drug monitoring and pharmacokinetic studies of MPA.