Abstract

A rapid and valid method is reported for the determination of levetiracetam (LEV) in human plasma with ultra high performance liquid chromatography (UHPLC) and ultraviolet (UV) detection. To 100 µl serum 50 µl lamivudine (IS, 10 µg/ml) was added as an internal standard and the mixture subjected to liquid extraction using 1 ml ethylacetate. A mixture of acetonitril and distilled water (80:20) was used as mobile phase and the analysis performed on a Blue Orchid C₁₈ (1.8 µm, 50 × 2 mm) column using diode array detector operated at 205 nm. The drug and IS were eluted at 0.8 and 1.2 min, respectively. The retention times for LEV and IS were 0.8 and 1.2, respectively. The method was rapid with analytical run time of 1.2 min and sensitive to the measurement of LEV in human serum following single dose administration of the drug with limit of detection (LOD) and limit of quantification (LOQ) at 0.02 and 0.05 µg/ml, respectively. Calibration curves (mean correlation coefficient = 0.9988) were linear over the concentration ranges of 0.05 to 1 µg/ml. The valid method was used in a randomized crossover bioequivalence study of two different LEV preparations in 24 healthy volunteers.

Key words: Levetiracetam, ultra high performance liquid chromatography (UHPLC), diode array detector, bioequivalence study.