A sensitive and rapid ultra high-performance liquid chromatography with tandem mass spectrometric assay for the simultaneous quantitation of cyclophosphamide and the 4-hydroxycyclophosphamide metabolite in human plasma.

ABSTRACT: Analysis of cyclophosphamide (CP) and its metabolite, 4-hydroxycyclophosphamide (4OHCP), in a single assay has the ability to improve sampling techniques benefitting both the patients who are receiving the drug and the clinicians drawing samples. Due to instability in plasma (t1/2?=?4?min), immediate stabilization of 4OHCP with phenylhydrazine is necessary upon sample draw. After stabilization, 4OHCP and the stable CP prodrug concentrations can be analytically measured to elucidate the pharmacokinetics, including half-life and exposure parameters (Cmax and AUC). For this purpose, a sensitive analytical method was developed to measure both the prodrug and active metabolite. A liquid-liquid extraction recovered the analytes prior to analysis with an ultra HPLC-MS/MS. A Thermo Scientific™ Hypersil™ BDS C18, 2.1?×?100?mm, 3.0??m column was used for compound separation. Mass transitions for CP (m/z 261.0???140.0), the internal standard d4-CP (m/z 265.0???140.0), 4OHCP (m/z 367.3???147.1), and the internal standard AZD7451 (m/z 383.4???341.1) were monitored over a calibration range of 34.24-34,240?ng/mL and 3.424-3424?ng/mL for CP and 4OHCP, respectively. Each calibration range proved accurate (<15% deviation) and precise (<15% RSD) for the desired compound. Using this method, CP and 4OHCP plasma levels can be measured in clinical samples from patients receiving this therapy.

SUBMITTER: Hall OM 

PROVIDER: S-EPMC5927828 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature