Liquid chromatographic method for the determination of rizatriptan in human plasma

A high-performance liquid chromatographic (HPLC) method with fluorescence detection has been developed for the determination of rizatriptan in human plasma. Following a sin.-le-step liquid-liquid extraction with methyl tertiarybutyl ether, the analytes were separated using a mobile phase consisting of 0.05% (v/v) triethylamine in water (adjusting to pH 2.75 with 85% phosphoric acid) and acetonitrile (92:8, v/v). Fluorescence detection was performed at an excitation wavelength of 225 nm and an emission wavelength of 360 run. The linearity for rizatriptan was within the concentration range of 0.5-50 ng/ml. The intra- and inter-day precisions of the method were not more than 8.0%. The lower limit of quantification (LLOQ) was 0.5 ng/ml for rizatriptan. The method was sensitive, simple and repeatable enough to be used in pharmacokinetic studies. (C) 2004 Elsevier B.V. All rights reserved.