Rapid determination of mycophenolic acid in plasma by reversed-phase high-performance liquid chromatography

A simple, accurate and sensitive high-performance liquid chromatographic method with UV detection was carried out to measure plasma concentrations of mycophenolic acid. Following a simplified acid hydrolysis of the sample, the separation was carried out in 4 min using a Zorbax® Eclipse® C₈ reversed-phase column with a flow-rate of 1.5 ml/min, and monitoring the absorbance at 250 nm. Throughput was up to 100 samples in 24 h. Within the investigated concentration ranges of mycophenolic acid (0-100 mg/l), good linearity (r>0.99) was obtained. The method is sensitive (the limit of detection was about 20 μg/l) and precise (for 0.49 mg/l added to plasma, within-run C.V. was 2% and between-run was 4.2%; for 2.88 mg/l, within-run C.V. was 0.35% and between-run C.V. was 0.69%; for 24.38 mg/l, within-run C.V. was 0.77% and between-run C.V. was 3.1%). Analytical recoveries were 96% for 0.5 mg/l mycophenolic acid added to plasma, 100% for 12 mg/l and 102.5% for 24 mg/l.