High performance liquid chromatographic method for the determination of sumatriptan with fluorescence detection in human plasma

A rapid and sensitive high performance liquid chromatography (HPLC) method with fluorescence detection has been developed for the determination of sumatriptan in human plasma. The procedure involved a liquid-liquid extraction of sumatriptan and terazosin (internal standard) from human plasma with ethyl acetate. Chromatography was performed by isocratic reverse phase separation on a C18 column. Fluorescence detection was achieved with an excitation wavelength of 225 nm and an emission wavelength of 350 nm. The standard curve was linear over a working range of 1-100 ng/ml and gave an average correlation coefficient of 0.9997 during validation. The limit of quantitation (LOQ) of this method was 1 ng/ml. The absolute recovery was 92.6% for sumatriptan and 95.6% for the internal standard. The inter-day and intra-day precision and accuracy were between 0.8-3.3 and 1.1-6.3%, respectively. This method is simple, sensitive and suitable for pharmacokinetics or bioequivalence studies.