Manual and automated (robotic) high-performance liquid chromatography methods for the determination of mycophenolic acid and its glucuronide conjugate in human plasma.

A manual and an automated (Zymark PyTechnology robot) HPLC method for simultaneous determination of plasma mycophenolic acid (MPA) and its glucuronide conjugate (MPAG) are described here. Both methods are reproducible and accurate, and both are equivalent in all respects, including quantification limits (MPA, 0.100 microgram/ml; MPAG, 4.00 micrograms/ml), range (using 0.05-0.5 ml of plasma: MPA, 0.0500-20.0 micrograms/aliquot; MPAG, 2.00-200 micrograms/aliquot), precision, and accuracy. MPA and MPAG were stable under the conditions used with both methods. Results from aliquots of paired control samples, analyzed by the manual method over three years at six analytical laboratories, showed excellent agreement in precision and accuracy.