Concurrent Determination of Emtricitabine and Efavirenz in Tablet Formulations using a Robust UPLC Method

This study focused on advancement and validation of an ultra-high pressure liquid chromatography (UHPLC) method for concurrent determination of emtricitabine and efavirenz in drug formulations1. Leveraging the advanced capabilities of RP- UPLC technology1, this method offers superior resolution, reduced analysis time, and enhanced sensitivity compared to conventional chromatographic techniques. The chromatographic separation was performed on a ultra-performance Grace Smart C18 column, (4.6 X 50mm, 1.7µm) employing a grasdient elution with methanol as organic phase and phosphate buffer (pH 3.0) in the combination of 65:35 at a detection wavelength optimized at 260nm1. The run time of the method is about 5 minutes, ensuring rapid throughput for routine analysis. Validation was conducted in strict adherence to ICH Q2(R1) guidelines, encompassing parameters such as specificity, linearity, accuracy, repeatability and robustness. Notably, the method demonstrated exceptional linearity over the concentration ranges of 10–50µg/mL for emtricitabine and 20–100 µg/mL for efavirenz, correlation coefficients exceeding 0.9991. The method’s precision and accuracy were corroborated through intra- and inter-day studies, with recovery rates consistently ranging between 98–102%. LOD, LOQ were found within the limits. Robustness was evaluated under deliberate modifications obtained in different operating environments under critical conditions, affirming the reliability of the method in diverse operational settings1. Furthermore, the approach exhibited excellent selectivity, with no interference observed from excipients or degradation products. This innovative RP-UPLC method stands out as a powerful analytical tool, offering unparalleled speed and precision for the quality control of emtricitabine and efavirenz1.