DETERMINATION OF THE CONCENTRATIONS OF 5-FLUOROURACIL AND ITS METABOLITES IN RABBIT PLASMA AND TISSUES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The concentrations of 5-fluorouracil, 5-fluoro-5,6-dihydrouracil, 5-fl uorouridine and 5-fluoro-2'-deoxyuridine in plasma, liver, kidney, lun g and heart of rabbits were determined by high-performance liquid chro matography (HPLC) after drug administration by two different routes. H PLC was carried out by using a Spherisorb 5 ODS 2 column and 0.05 M ph osphate buffer as the mobile phase with UV detection at 200 nm. The pH of the mobile phase, organic modifier content and column temperature were found to have a profound influence on the results, hence it was n ecessary to optimize a procedure for each matrix. A comparison of the efficiency of intravenous and peritoneal administration revealed that the latter provides higher drug concentrations in the liver and minima l contents in plasma and all other tissues studied.