Selective Spectrofluorimetric Method and Uncertainty Calculation for the Determination of Camptothecin in the Presence of Irinotecan and Topotecan

Abstract

A selective fluorimetric method was developed to quantify camptothecin (CPT) in irinotecan (CPT-11) and in topotecan (TPT) based anti-cancer drugs. Selectivity was achieved by experimental optimization and using synchronized scanning and second-order spectral derivatization. The limits of quantification for CPT were in the order of 1 × 10−7 mol L−1 with a linear response up to 1 × 10−5 mol L−1. The combined uncertainty associated with the CPT fluorescence measurement at a 5 × 10−7 mol L−1 level were 10.9% and 6% of the reference level, respectively, for TPT and CPT-11 based pharmaceutical formulations. The CPT recoveries of 95 ± 12% and 91 ± 5.6% (n = 3) were achieved, respectively, in samples containing CPT-11 and TPT.