Resumo:
Pre-exposure prophylaxis (PrEP) against the Human Immunodeficiency Virus (HIV), using Truvada®, involves the administration of a fixed-dose oral combination containing the drugs tenofovir disoproxil fumarate (TDF) 300 mg and emtricitabine (FTC) 200 mg. This antiretroviral medication, whose primary objective is to prevent the seroconversion of HIV in the body, was made available by the Brazilian Health System (SUS) in 2017. However, stability-indicating analytical methods (SIAM) that ensure the safe use of these combined drugs in a single pharmaceutical form remain scarce. Given their therapeutic importance, this study aimed to develop an SIAM for the simultaneous analysis of TDF and FTC in Active Pharmaceutical ingredients (APIs) and coated tablets. The drugs were subjected to forced degradation under acidic, basic, neutral, and oxidative conditions. The reverse-phase High-Performance Liquid Chromatography (HPLC) method was developed using a diode-array detector (DAD). Chromatographic separation was performed on a Zorbax® C8 column (250 x 4.6 mm, 5 μm), with a mobile phase composed of methanol and water in gradient mode, maintained at 25 °C, with a flow rate of 1.0 mL/min and detection at 258 nm for TDF and 280 nm for FTC. The degradation studies demonstrated that the drugs degraded in all conditions, although degradation products were only observed in acidic and neutral media. Additionally, the research showed that all validation parameters met the requirements of major regulators' guidelines, revealing a selective, linear, precise, accurate, sensitive, and robust method for simultaneously quantifying TDF and FTC.
