Analysis of the chemotherapy drug 5-fluorouracil and its metabolites by surface-enhanced Raman spectroscopy

Chemotherapy drug dosage is based on the limited statistics of the response of previously treated patients and administered according to body surface area. Considerably better dose regulation could be performed if the drug metabolism of each patient could be monitored. Unfortunately, current technologies require multiple withdrawals of blood to determine metabolism, a precious fluid in limited supply. Saliva analysis has long been considered an attractive alternative, but unfortunately standard techniques require large quantities that are difficult to obtain. In an effort to overcome this limitation we have been investigating the ability of metal-doped sol-gels to both separate drugs and their metabolites from saliva and generate surface-enhanced Raman spectra. Surface-enhanced Raman spectroscopy has the potential to perform this analysis with just a few drops of sample due to its extreme sensitivity. Preliminary measurements are presented for the chemotherapy drug, 5-fluorouracil, and its two metabolites 5-fluorouridine and 5-fluoro-2'-deoxyuridine, and the potential of determining metabolism on a patient-by-patient basis.