Simple method based on fluorescent detection for the determination of 4-hydroxycyclophosphamide in plasma

Ther Drug Monit. 2002 Jun;24(3):405-9. doi: 10.1097/00007691-200206000-00013.


Cyclophosphamide is a prodrug used both as a single drug and in combination chemotherapy. Cyclophosphamide is converted to its active metabolite (4-hydroxycyclophosphamide) by the cytochrome P450 enzymes. A liquid chromatography method including liquid-liquid extraction and protein precipitation in one step was developed to measure 4-hydroxycyclophosphamide in plasma. The 4-hydroxycyclophosphamide was stabilized and converted to a fluorescent dansylhydrazone derivative, which was chromatographed on a reverse-phase column and detected using a spectrofluorometric detector at excitation of 350 nm and emission of 550 nm. The limit of quantitation was 60 ng/mL and the between-day accuracy and precision were less than 9%. The method was applied to the analysis of plasma from patients who had received an intravenous infusion of 1 g/m(2) cyclophosphamide.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid
  • Cyclophosphamide / administration & dosage
  • Cyclophosphamide / analogs & derivatives*
  • Cyclophosphamide / blood*
  • Cyclophosphamide / pharmacokinetics*
  • Drug Monitoring / methods
  • Drug Monitoring / standards*
  • Fluorescence
  • Humans
  • Immunosuppressive Agents / administration & dosage
  • Immunosuppressive Agents / blood
  • Immunosuppressive Agents / pharmacokinetics*
  • Infusions, Intravenous
  • Reproducibility of Results


  • Immunosuppressive Agents
  • 4-hydroxycyclophosphamide
  • Cyclophosphamide