Pharmacokinetic studies on 5-fluorouracil and its metabolite in rabbits by high pressure liquid chromatographyi

A simple and specific HPLC method was developed to determine simultaneously 5-fluorouracil (5-FU) and its metabolite, 5-fluoro-2'-deoxyuridine( FUdR), in serum. 5-Bromouracil (5-BU) was added as an internal standard before extraction with 16% isopropanol in ethyl acetate. The extracts were then chromatographed using a mobile phase of water at a flow rate of 2 ml/min. Detection was made at 270 nm. The peak height ratias of 5-FU or FUdR to 5-BU were measured. After single iv doses to rabbits, pharmacokinetic parameters were compared between 6 normal white New Zealand rabbits and 6 hybrid rabbits. The A. B, Kio and Vi values were found to be significantly different between these 2 kinds of rabbits.