HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC AND MEGABORE GAS-LIQUID-CHROMATOGRAPHIC DETERMINATION OF LEVETIRACETAM (UCB L059) IN HUMAN SERUM AFTER SOLID-PHASE EXTRACTION

For monitoring drug levels of the new potential anticonvulsant drug levetiracetam (ucb L059) in human serum, two assay methods were developed and compared. A solid-phase extraction procedure was followed by either reversed-phase HPLC separation and UV-detection or GLC separation using cold on-column injection on a megabore column and nitrogen-phosphorous detection. Absolute recovery of the drug exceeded 97%. Precision and accuracy values for the 16.0 mu g/ml quality control sample were 2.4% and 101 +/- 5% (n = 10), respectively, for the GLC method. Precision and accuracy values for the 12.1 mu g/ml quality control sample were 1.0% and 100 +/- 1% (n = 7), respectively, for the HPLC method. Agreement between both methods was excellent (r = 0.993). Both methods are suitable for pharmacokinetic studies and therapeutic drug monitoring as well. Serum level data for levetiracetam in a patient on chronic antiepileptic medication are presented.