Abstract

¹⁹F NMR provided a highly specific tool for identification of efavirenz in human serum and pharmaceutical preparations as well as a suitable analytical technique for their absolute quantification. The method is based on the integration of appropriate signals of efavirenz and potassium fluoride, as an internal standard. The proposed method is simple and reliable, but when it is used without any sample pretreatment, there is a manipulation of large sample volumes and lengthy analysis time. The calibration curve for efavirenz in human serum was linear over the range of 0.8 to 1000 mgL⁻¹, with detection limit of 0.3 mgL⁻¹. The mean error on human serum samples ranged from about -4 to -6%, with relative standard deviations of <8%. The method was also applied successfully for the determination of efavirenz in real pharmaceutical samples,and compared with the results obtained by a reference high-performance liquid chromatography-ultraviolet (HPLC-UV) method.

Key words: Efavirenz, ¹⁹F NMR analyses, HIV, serum, pharmaceuticals.