Abstract

This work presents the development of analytical methodologies using high performance liquid chromatography, for the quantification and characterization of new compounds of synthesis with potential antichagasic activity. Such compounds belong to the 2-(o-nitrophenyl)-benzimidazol N-substituted series: N-(p-nitrobenzoyl)-2-(o-nitrophenyl)-benzimidazol and N - (m-nitrobenzoyl)-2-(o-nitrophenyl)-benzimidazol. Different mobile phases (different proportions of acetonitrile-methanol-water- 50 mM phosphate buffer), columns (C-8 and C-18), temperatures and pHs were tested. The optimal conditions were selected on the basis of the adequate combination between resolution (R), capacity factor (k '), selectivity (α), retention times values of every signal and the total time of the chromatogram, using a photodiode array detector for the quantification. The System Suitability Test (USP 27) was carried out in the presence of the synthesis precursors of each compound and the derived products from the corresponding hydrolysis and photolysis degradation test, to find the optimal conditions of selectivity in every case. The developed methodologies exhibited adequate analytical characteristics of repeatability and reproducibility for his application (CV <1 %), using the calibration curve method (range: 1×10-5 - 1×10-4 M). The detection and quantification limits were adequate and the methodologies were successfully applied to stability studies of each compound, finding that the hydrolysis stability was pH-dependent, and becomes to be maxima and instantaneous in pH alkaline. Also, the calculated degradation constants, reaction order, half-lives and the corresponding activation energies are informed. This work was financed by Project FONDECYT 1061144.