Letrozole is an aromatase inhibitor used in breast cancer treatment. However, during the synthesis of the drug, impurities may be formed that can affect its efficacy and safety. These impurities can be residual solvents, reagents, or related compounds. Therefore, it is crucial to identify and quantify these impurities to ensure the quality and purity of the final product. Various analytical techniques are used to detect and quantify Letrozole impurities, including high-performance liquid chromatography (HPLC), gas chromatography (GC), and mass spectrometry (MS).
