Stability of mycophenolic acid in plasma samples from patients during mycophenolate mofetil therapy.

The aim of this study was to investigate the stability of mycophenolic acid (MPA) in human plasma from patients receiving mycophenolate mofetil (MMF) therapy. MPA was measured using a validated HPLC method. MPA concentrations were determined immediately after receiving the samples in the laboratory, and after 24 h, 72 h, 96 h, 7, 14, 21 days of storage at two different temperatures at -20 degrees C and 4 degrees C. The number of samples used in different conditions of temperature was limited by plasma volume in patients specimens. Monitoring human plasma samples stored at -20 degrees C showed that MPA was stable at this temperature for at least 3 weeks. MPA concentrations were found to be stable also up to 96 hours when stored at 4 degrees C.