title: In vitro stability study of methotrexate in blood and plasma samples for routine monitoring.
abstract: A study was conducted to assess the stability of methotrexate (MTX) in pooled plasma and whole blood samples during an 11-day period. The concentrations were determined by liquid chromatography with UV detection over time, in the dark or in light, at different temperatures (4 degrees C or room temperature), and for a low and a high concentration level (0.6 and 2.5 microg/mL, 1.32 and 5.5 micromol/L, respectively). The accuracy, linearity, and variability of the method were assessed. This work demonstrates that blood samples are stable for 2 days at room temperature and for 6 days at 4 degrees C. Furthermore, there is no significant loss (<17%) in plasma at any of the investigated temperatures for at least 6 days. This study shows that whole blood samples can be stored for 3 days before centrifugation and that plasma samples can be reanalyzed after 6 days without any loss.
authors.affiliation: Department of Pharmacy, Pharmacokinetics and Therapeutic Drug Monitoring, Pitié-Salpêtrière Hospital (AP-HP), Paris, France.
authors.forename: Nadège
authors.initials: N
authors.lastname: Limelette
authors.forename: Mathieu
authors.initials: M
authors.lastname: Ferry
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Branger
authors.forename: Alain
authors.initials: A
authors.lastname: Thuillier
authors.forename: Christine
authors.initials: C
authors.lastname: Fernandez
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D016903:Drug Monitoring / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D008727:Methotrexate / Q000097:blood*; D013696:Temperature
chemical_list: D008727:Methotrexate