Flecainide is a drug used to treat cardiac arrhythmias, but it is important to ensure that it is pure and free of impurities. Impurities can lead to adverse side effects, reduced efficacy, and even toxicity. Flecainide impurities can be caused by a variety of factors, including manufacturing processes, storage conditions, and environmental factors. It is important for pharmaceutical companies to carefully monitor and control the quality of flecainide to ensure that it is safe and effective for