SIMULTANEOUS DETERMINATION OF FELBAMATE AND 4 METABOLITES IN RAT CEREBROSPINAL-FLUID BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

An isocratic liquid chromatographic method for direct sample injection has been developed for the quantitation of felbamate and four metabol ites in rat cerebrospinal fluid. The method uses 0.050- or 0.025-ml al iquots of cerebrospinal fluid diluted with equal volumes of internal s tandard. Chromatography is performed on a 150 mm x 4.6 mm I.D. Spheris orb ODS2, 3-mu m HPLC column eluted with a phosphate buffer-acetonitri le-methanol (820:120:60, v/v/v) mobile phase and ultraviolet absorbanc e detection at 210 nm. The linear quantitation ranges/are: felbamate a nd the 2-hydroxy metabolite 0.195-200 mu g/ml, the propionic acid meta bolite 0.195-50.0 mu g/ml, the p-hydroxy metabolite 0.781 to 50.0 mu g /ml, and the monocarbamate metabolite 0.098-50.0 mu g/ml.