Determination of isepamicin in human plasma by HPLC with fluorescence detection after derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate.

A simple and rapid high-performance liquid chromatographic method has been developed for determination in human plasma of isepamicin (ISP), an aminoglycoside antibiotic agent. After protein precipitation and clean-up procedure to remove lipophilic contaminants, ISP is derivatized pre-column with 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate for fluorescence detection. Chromatographic separations are achieved using C(18) column and mobile phase consisting of 20 mM KH(2)PO(4) containing 8 mM triethylamine (pH 7.0) and acetonitrile (78/22, v/v). Amikacin was used as an internal standard. The calibration curve was linear over a concentration range of 0.5-50 microg/ml. The limit of quantification was 0.5 microg/ml. The intra- and inter-day variabilities of ISP were both less than 17.5%. Both derivatives were stable for at least a week at ambient condition. This assay procedure should have useful application in therapeutic drug monitoring of ISP.