부산대학교 도서관

Colistin, in the form of colistin methanesulfonate sodium (CMS), has a narrow therapeutic window, and colistin levels must be monitored during treatment. The aim of this study was to develop and validate a high-performance liquid chromatography-fluorescence detection (HPLC-FLD) method for measuring colistin in human serum. Colistin was extracted from human serum using trichloroacetic acid and methanol for protein precipitation, followed by in-solid phase extraction derivatization with 9-fluorenylmethyl chloroformate. HPLC-FLD system using a reverse-phase HPLC C18 column and a mobile phase consisting of acetonitrile, tetrahydrofuran, and water (80%:4%:16%) were used for the quantification of colistin A, colistin B, and polymyxin B (internal standard) in human serum. The extraction recoveries were between 71% and 103%. Linear calibration curves were obtained for colistin in concentrations from 0.3 to 8.0 μg/mL, with good fit (r2 = 0.9993). The lower limit of quantitation was 0.3 μg/mL. The intra- and inter-day precision of the assay was 0.5–5% and 3.5–9.4%, respectively. The accuracy ranged from 98% to 100%. This validated method was successfully applied to the analysis of serum-receiving CMS in critically ill patients. This method will be useful to assist colistin dosage adjustment based on individual blood colistin levels for optimization of colistin therapy. [ABSTRACT FROM AUTHOR]