Validation of a high-performance liquid chromatography method for the measurement of mycophenolic acid and its glucuronide metabolites in plasma.
OBJECTIVE
The need for therapeutic drug monitoring of the immunosuppressant mycophenolic acid is becoming more evident. This paper describes a simple high-performance liquid chromatography procedure for the simultaneous quantitation of mycophenolic acid (MPA) and its glucuronide metabolites in plasma using protein precipitation followed by HPLC analysis with isocratic elution and UV detection.


METHODS
The performance of this method is compared to the EMIT 2000 MPA immunoassay (Dade Behring Diagnostics Inc., Cupertino, California, USA).


CONCLUSIONS
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 (r(2) = 0.851), and was determined to be suitable for therapeutic drug monitoring and pharmacokinetic studies of MPA.
Westley
Ian S
IS
Department of Clinical Pharmacology, The Queen Elizabeth Hospital, 28 Woodville Road, Woodville, South Australia 5011, Australia.
Sallustio
Benedetta C
BC
Morris
Raymond G
RG
D001681:Biological Assay / Q000592:standards; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017248:Enzyme Multiplied Immunoassay Technique; D020719:Glucuronides / Q000097:blood* / Q000378:metabolism*; D006801:Humans; D009173:Mycophenolic Acid / Q000097:blood* / Q000378:metabolism*; D015203:Reproducibility of Results
D020719:Glucuronides; D009173:Mycophenolic Acid