Simultaneous HPLC determination of 5‐fluorouracil and its metabolites in plasma of cancer patients

Abstract

5-Fluorouracil (5-Fu) is a commonly used anticancer agent for treatment of solid tumours. Certain studies have reported conflicting results between individual plasma concentration levels and toxicity or therapeutic effects. For this reasons some authors proposed to evaluate the plasma levels of 5-Fu metabolites 5-fluorouridine, 5-fluoro-2'-deoxyuridine and 5-fluoro-5,6-dihydro-uracil. The aim of the present work is to develop and validate a new HPLC method simultaneously determining 5-fluorouracil and its three metabolites, to be used to study the plasma levels, therapeutic effects and toxicity in cancer patients. The analytes were separated on a 4.6 x 250 mm ODS1 (5 micro m) not end-capped column, operating at room temperature. Elution was performed under isocratic conditions, employing a 1.5 mM K(3)PO(4) mobile phase (pH 5). 5-Bromo-5,6-dihydro-uracil was used as internal standard. The limits of quantitation were 0.5 micro g/mL for 5-fluorouracil, 1 micro g/mL for 5-fluoro-5,6-dihydro-uracil, 3 micro g/mL for 5-fluoro-2'-deoxyuridine and 5-fluorouridine; the stability, recovery, linearity, accuracy and specificity of the compounds were evaluated according to the criteria widely accepted. Using this method we measured plasma samples of 18 cancer patients treated with folinic acid (100 mg/m(2)) by intravenous administration, followed by an i.v. bolus of 5-Fu (400 mg/m(2)). The concentration levels of 5-fluorouracil and for 5-fluoro-5,6-dihydro-uracil were detectable in all the subjects while 5-fluorouridine and 5-fluoro-2'-deoxyuridine were present only in eight patients.

Assay of urinary α‐fluoro‐β‐alanine by gas chromatography–mass spectrometry for the biological monitoring of occupational exposure to 5‐fluorouracil in oncology nurses and pharmacy technicians

“…Although several analytical methods have been published to measure 5FU and its pyrimidine metabolites (Sommadossi et al, 1982;Soylu et al, 1988;Sastre Torano et al, 2001;Casale et al, 2002), only a few are focused on measuring its main urinary metabolite, AFBA (Anderson et al, 1997;Van Kuilemburg et al, 2001). In particular, in the field of occupational medicine, the measurement of AFBA in urine has been employed to assess the exposure of a few pharmaceutical workers to 5FU during handling and packaging of the bulk drug (Sessink et al, 1994) and of hospital nurses and pharmacy technicians during preparation of pharmaceutical doses for patient treatment (Sessink et al, 1992).…”

Hydrophilic interaction liquid chromatography–APCI–mass spectrometry determination of 5-fluorouracil in plasma and tissues

“…Several techniques have been developed in the last 25 years for the quantitation of 5-FU, related pro-drugs, and their metabolites, in biological matrices. Among many published analytical methods, HPLC-UV is the most frequently reported technique for the determination of 5-FU in plasma, serum, tissue and urine [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Methods using HPLC methods with fluorescence detection [20,21] have also been described although derivatisation is required and sample pre-treatment procedures are more complex.…”

Biological monitoring of occupational exposure to 5-fluorouracil: Urinary α-fluoro-β-alanine assay by high performance liquid chromatography tandem mass spectrometry in health care personnel

“…After administration, 5-FU undergoes two metabolic pathways. The drug is anabolized to the nucleotide level to exert its cytotoxic effects against tumour cells while the catabolic pathway leads to the reduction of the heteroaromatic ring to 5,6-dihydro5-fluorouracil and further ring opening produces ␣-fluoro-␤-alanine (FBAL), an unnatural amino acid [16,17], as shown in Fig. 1.…”