Desenvolvimento e validação de métodos analíticos para a quantificação dos antimaláricos artesunato e mefloquina

Abstract

Malaria is the most important parasitic disease in the world, placing it among the biggest challenges for the poorest countries in the area of health and development. It is estimated that in 2010 there were 216 million cases of malaria worldwide, with approximately 81% of cases in the African region. Also, it is estimated that there were 655,000 deaths, 91% of which occurred on the African continent. Approximately 86% of deaths were caused by malaria in children under 5 years of age. In Brazil, were reported to the Ministry of Health about 330,000 cases of the disease in 2010. In order to prolong the life cycle of the drug, particularly for delaying the onset of resistance, the treatment of malaria infection is performed using drug combinations. Moreover, it is necessary to monitor the plasma concentration of the drugs, correlating it with parasitemia. It is recommended, in the therapeutic manuals of malaria, combination therapy of artemisinin or its derivatives with other antimalarial drugs or antibiotics. In this study, we evaluated the combination of artesunate and mefloquine in salt form and the fixed-dose combination. Also, a bioanalytical method was developed and validated for the determination of artesunate, dihydroartemisinin (artesunate´s main metabolite) and mefloquine in human plasma. The salt artesunate mefloquine (MEFAS) was characterized as to its melting point, infrared spectrum and the chromatographic profile, with impurities that did not allow its use as pharmaceutical raw material. An analytical method for the determination of artesunate and mefloquine hydrochloride in fixed dose combination tablets was developed and validated. The parameters evaluated were selectivity, linearity, precision, accuracy and robustness, according to current legislation. We evaluated the stability of the solutions, which remained stable for at least 8 hours. Samples of four different batches of tablets were analyzed using the developed method and presented adequate drugs content. A bioanalytical method for the determination of artesunate, dihydroartemisinin (metabolite of artesunate) and mefloquine in plasma was developed and validated. The detection was performed using liquid chromatography tandem mass spectrometry. The method was validated according to current legislation. The parameters evaluated were selectivity, residual effect (carry over), matrix effect, linearity, precision, accuracy, and stability in biological matrix, after cycles of freezing and thawing, short term, post-processing and in solution. The bioanalytical method developed is adequate and can be used in studies of therapeutic drug monitoring.