LC-MS Method Development for Simultaneous Determination of Tamoxifen and Aprepitant

Background/Purpose: In this study, an analytical method was developed for the simultaneous analysis of tamoxifen, used in the treatment of breast cancer, and aprepitant, used to prevent chemotherapy-induced nausea and vomiting. In the literature search, no studies were found that analyzed these two drugs simultaneously. Therefore, this study focused on the development of an LC-MS method for the rapid and selective simultaneous analysis of these two active pharmaceutical ingredients.Methods: The method development process involves the systematic analysis and optimisation of MS parameters such as ionisation mode, m/z values, detector voltage and gas flow rates as well as chromatographic conditions, including column selection, mobile phase composition and pH.Results: Optimal conditions: ESI, (+) ionization mode, m/z = 372.15 for tamoxifen and m/z = 535.20 for aprepitant, Inertsil C18 (50 × 2.1 mm, 3 µm) column, 50/50 (v/v) ACN/H₂O (pH = 2.5) was determined as the mobile phase. Under these conditions, the retention time was found to be 1.58 minutes for tamoxifen and 2.25 minutes for aprepitant. The developed method is a fast and selective with a total analysis time of 3 minutes.Conclusion: The LC-MS method developed in this study is suitable for the simultaneous analysis of TMX and APT; it is rapid, accurate, selective and simple method with a total analysis time of 3 minutes, and following validation studies, it can be safely used for the routine analysis of these two drugs. Furthermore, the findings of this study make a significant contribution to the literature.