Determination of 4-hydroxyifosfamide in biological matrices by high-performance liquid chromatography.
A high-performance liquid chromatographic method has been developed for the determination of 4-hydroxyifosfamide, a metabolite of ifosfamide, in plasma of cancer patients. The analyte is derivatized to 7-hydroxyquinoline, which can be detached fluorimetrically. The calibration graph is linear in the concentration range 0.05-25 microM, the limit of detection being 40 nM. Any inference from acrolein, another metabolite of ifosfamide, was ruled out. 4-Hydroxyifosfamide is very unstable in plasma and a stabilization procedure by adding citric acid has been developed. Thus treated, the samples were stable for 4 days. Analysis of a patient's plasma samples revealed that the 4-hydroxifosfamide concentration did not exceed 10 microM.
Kaijser
G P
GP
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Utrecht University, The Netherlands.
Ter Riet
P G
PG
de Kraker
J
J
Bult
A
A
Beijnen
J H
JH
Underberg
W J
WJ
D002528:Cerebellar Neoplasms / Q000097:blood*; D002648:Child; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006801:Humans; D007069:Ifosfamide / Q000031:analogs & derivatives* / Q000097:blood; D008527:Medulloblastoma / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
C039771:4-hydroxyifosfamide; D007069:Ifosfamide