Determinação de benznidazol em plasma humano utilizando microextração por sorvente empacotado e cromatografia a líquido de alta eficiência.

Abstract

Chagas disease still affects 6 to 7 million people in Latin America and still causes around ten thousand deaths per year, according with the World Health Organization. The disease is caused by the parasite Trypanosoma cruzi, which is transmitted to human beings through the bite of the triatomid barber. In the chronic phase of the disease may occur cardiac arrhythmia, heart failure, heart attack or even death. Benznidazole is the main drug used for Chagas disease treatment. The determination of plasmatic concentration in humans is important for pharmacokinetics studies, clinical trials, new drugs development and therapeutic monitoring. In this context, the development of suitable analytical methods is fundamental. The use of microextraction by packed sorbent (MEPS) in sample preparation aim to reduce toxic and high purity solvents use, likewise the sample amount. Thus, with this study, we develop a bioanalytical method using MEPS on sample preparation and high performance liquid chromatography with UV detection. A previous sample preparation step was performed with protein precipitation with 10% w/v trichloroacetic acid, in order to avoid deterioration of the MEPS cartridge. The optimization of the MEPS was performed through a 24 factorial planning, obtaining a recovery of about 25% of the analyte using 500 µL of plasma, 10 cycles of 100 µL sample aspiration and ejection, and desorption with three times of 50 µL of acetonitrile. The bioanalytical method was developed and validated, proving to be selective, precise, accurate, robust and linear in the concentration range 0.5 to 6.0 µg/mL. Finally, the method applicability was showed in the analysis of plasma samples from three volunteers, which made use of benznidazole. The developed bioanalytical method can be used in pharmacokinetic studies, therapeutic drug monitoring and bioequivalence studies.