Room-temperature phosphorimetry for the determination of trace contaminations of camptothecin in anticancer drugs

Campthotecin derivatives, irinotecan (CPT-11) and topotecan (TPT), have been used for the treatment of cancer and camptothecin (CPT) is a potential contaminant in these anticancer medicines. In this work, room-temperature phosphorimetry was used to quantify either CPT as trace contaminants in anticancer drugs and CPT-11 as the main ingredient in anticancer medicines. Phosphorescence from CPT-11 was induced using Pb(NO(3))(2) in SDS treated cellulose substrate while CPT was selectively detected using TINO(3) as a phosphorescence enhancer in either cellulose or nylon substrates. The limit of quantification for CPT and CPT-11 was in ng order. A detailed metrological study was made to calculate the combined uncertainty associated to the CPT phosphorescence measurement. Satisfactory analyte recoveries were obtained for CPT-11 as a main active ingredient of a pharmaceutical formulation. The selective determination of CPT in a matrix containing TPT was made using the higher order (2nd) derivative of the excitation spectra. The results demonstrated the applicability of the method due its simplicity, cost effectiveness and selectivity. (C) 2010 Elsevier B.V. All rights reserved.