Determination of the Camptothecin Derivatives CPT-11 and SN-38 in Urine and Saliva by Micellar Electrokinectic Chromatography

Abstract

The anti-cancer synthetic drug irinotecan (CPT-11) and its active metabolite SN-38 have been determined by micellar electrokinetic capillary chromatography (MEKC). The detection of the analytes was made at 368 nm and their separation took less than 7 min using a borate buffer (pH 8.8 at 25 mmol L−1) solution containing sodium dodecyl sulfate (45 mmol L−1) and acetonitrile (13.5% v/v). On-line analyte concentration (normal stacking mode) and the use of a highly sensitive cell (Z shaped cell) improved detection limits (at the 10−8 mol L−1 level). Recovery in fortified human saliva was 108 ± 5%, in agreement with the result achieved with the reference HPLC method. For the analysis of urine from rats submitted to a single dose of CPT-11 and SN-38, camptothecin was used as internal standard enabling recoveries close to 100% when compared to the results achieved using HPLC.