A review of analytical methods for the determination of 5-fluorouracil in biological matrices.

5-Fluorouracil (5-FU) is a cytostatic agent that has been widely used in the treatment of various solid tumours for more than 20 years, and is still considered to be among the most active antineoplastic agents in advanced colorectal cancer and malignancies of the head and neck. A large number of non-chromatographic and chromatographic methods for the quantitation of 5-FU, related prodrugs and their metabolites in biological matrices have been developed in the last 30 years to support preclinical and clinical studies. However, 5-FU monitoring has not been widely used, at least not in the USA, and certainly not outside the clinical research setting, given the absence of simple, fast and inexpensive testing methods for 5-FU monitoring. Recent developments with testing based on liquid chromatography-tandem mass spectrometry and a nanoparticle antibody-based immunoassay may facilitate routine monitoring of 5-FU in daily clinical practice. In this review the advantages and disadvantages of the bioanalytical methods developed and used for 5-FU, its metabolites and related prodrugs are discussed.

Penetration of orally administered prulifloxacin into human prostate tissue.

BACKGROUND AND OBJECTIVE: Prulifloxacin, a fluoroquinolone antibacterial agent, may be a useful addition to the antimicrobial armamentarium against prostatitis once the ability of its active metabolite, ulifloxacin, to penetrate prostatic tissue has been determined. This study set out to evaluate ulifloxacin penetration into the prostate following administration of the oral fluoroquinolone prodrug prulifloxacin in patients undergoing transurethral resection of the prostate (TURP). METHODS: This was a phase I, randomized, open-label, single-centre study involving 20 male Caucasian patients (mean age 63.1 years) requiring TURP for treatment of benign prostatic hyperplasia. Sixteen patients were randomized to receive prulifloxacin; the other four patients were not treated (controls) in order to validate the bioanalytical method. Patients in the active treatment groups were randomized to receive one or three once-daily doses of prulifloxacin 600 mg, with the last administration 3 hours prior to surgery. Central/transitional and peripheral zone prostatic tissue samples were obtained from the 6 o'clock and 9 o'clock positions in the prostate, and blood samples were collected concurrently. Ulifloxacin concentrations were determined in the tissue samples and plasma using liquid chromatography-tandem mass spectrometry. Safety was also assessed. RESULTS: Prostatic tissue concentrations of ulifloxacin always exceeded those in plasma. Mean ulifloxacin concentrations measured in samples collected from the 6 o'clock central/transitional zone of the prostate were higher in patients who received prulifloxacin for 3 days than in those who received a single dose. Mean prostatic tissue/plasma ulifloxacin concentration ratios after single and repeated prulifloxacin administration ranged from 3.8 to 7.1 and from 3.9 to 9.5, respectively. The highest mean ratio was found in the 6 o'clock central/transitional zone after repeated dosing. Prostatic levels of ulifloxacin were above the minimum inhibitory concentrations for the most common causative pathogens of bacterial prostatitis. No treatment-related toxicities were reported. CONCLUSION: These findings confirm the ability of prulifloxacin to penetrate prostatic tissues, indicating high exposure of the target tissue to ulifloxacin and, therefore, a potential therapeutic role for prulifloxacin in the treatment of bacterial prostatic infections.

Penetration of prulifloxacin into gynaecological tissues after single and repeated oral administrations.

OBJECTIVE: This study aimed to evaluate the penetration into gynaecological tissues of ulifloxacin, the active metabolite of prulifloxacin, a once-daily fluoroquinolone administered once or in repeated doses. METHODS: This was an open-label, randomised study that included 20 consenting female inpatients (age range 40-65 years) requiring total simple hysterectomy as a result of benign disease. Three groups of patients were enrolled: group A (four patients whose gynaecological tissue samples were used to set up the bioanalytical method); group B (eight patients treated 3 hours before surgery with one 600 mg tablet of prulifloxacin); group C (eight patients treated with prulifloxacin 600 mg once daily for 3 days and undergoing surgery 3 hours after the last dose). Patients to be treated with prulifloxacin were randomly allocated to group B or C. During surgery, samples of blood were collected jointly with healthy tissue removed from the endometrium, proximal fallopian tube, vaginal posterior fornix and portio vaginalis. Ulifloxacin concentrations in plasma and gynaecological tissues were determined by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) bioanalytical method. An intrastudy assessment of the bioanalytical method performance was also conducted for plasma and tissues using calibration and quality control data (spiked samples). RESULTS: Ulifloxacin mean concentrations were always higher in group C than in group B patients, both in plasma (0.76 vs 0.53 microg/mL) and in gynaecological tissues, namely fallopian tube (1.38 vs 0.81 microg/g), posterior fornix (1.48 vs 1.05 microg/g), portio vaginalis (1.46 vs 1.45 microg/g) and endometrium (2.20 vs 1.39 microg/g), as expected after repeated drug administrations. Tissue concentrations observed after repeated administrations were generally higher than the ulifloxacin minimum inhibitory concentrations for pathogens more frequently involved in gynaecological bacterial infections. The mean tissue/plasma ratios ranged between 1.5 and almost 3. CONCLUSION: The results of this study are promising but not fully predictive of clinical or microbiological efficacy for prulifloxacin. There is a need for appropriate clinical trials confirming that prulifloxacin is a useful therapeutic tool in patients with gynaecological bacterial infections.