Analysis of microdialysates from cancer patients by capillary electrophoresis

Microdialysis (MD) is an innovative clinical technique for measuring inters titial tissue pharmacokinetics and plasma-to-tissue transfer rates of drugs in humans. However, microdialysis requires the availability of specialized analytical techniques. Capillary electrophoresis (CE), which enables conce ntration measurements of small volume samples, theoretically constitutes an ideal analytical technique for measuring drug concentrations in microdialy sates. In the present experiments, we aimed at assessing the potential util ity and limitations of CE for analysis of microdialysates in a clinical sit uation. Microdialysates were obtained from primary breast cancer patients w ho received chemotherapy including 5-fluorouracil (5-FU; 600 mg/m(2)). Subs equently, 5-FU concentrations were measured in tumor - and subcutaneous adi pose tissue - microdialysates by CE. By combining MD and CE, complete time versus concentrations profiles could be obtained for 5-FU in the interstiti al tumor space and important clinical questions could be addressed. We conc lude that the combination of MD and CE leads to important anti previously i naccessible information about the drug distribution process in a clinical s etting.