Microextraction by packed sorbent and high-performance liquid chromatography for determination of benznidazole in human plasma

Benznidazole is the main drug used in Chagas disease and its determination in plasma samples is useful in several situations. Hence, robust and accurate bioanalytical methods are needed. In this context, sample preparation deserves special attention, as it is the most error-prone, labor-intensive and time-consuming step. Micro -extraction by packed sorbent (MEPS) is a miniaturized technique, developed to minimize the use of hazardous solvents and sample amount. In this context, this study aimed to develop and validate a MEPS coupled to high performance liquid chromatography method for the analysis of benznidazole in human plasma. MEPS optimi-zation was performed by a 24 full factorial experimental design, which resulted in about 25 % of recovery. The best condition was achieved when 500 mu L of plasma,10 draw-eject cycles, sample volume drawn of 100 mu L, and desorption with three times of 50 mu L of acetonitrile were used. The chromatographic separation was performed with a C18 (150 x 4.5 mm, 5 mu m) column. The mobile phase was composed of water:acetonitrile (60:40) at a flow rate of 1.0 mL min-1. The developed method was validated and proved to be selective, precise, accurate, robust and linear in the range from 0.5 to 6.0 mu g mL-1. The method was applied to three healthy volunteers that made use of benznidazole tablets and showed to be adequate to assess this drug in plasma samples.

Automated summary

This study aimed to develop and validate a MEPS coupled to high performance liquid chromatography method for the analysis of benznidazole in human plasma. The method was proved to be selective, precise, accurate, robust and linear in the range from 0.5 to 6.0 μg mL-1, and it was applied successfully to assess this drug in plasma samples.