Regadenoson is a pharmaceutical drug used in the diagnosis of heart diseases. Like any other drug, it may contain impurities that can affect its quality and safety. Regadenoson impurities refer to any unwanted substances that may be present in the drug, such as residual solvents, degradation products, or other contaminants. These impurities can impact the drug's efficacy, stability, and safety, and thus need to be monitored and controlled to ensure the drug's quality and safety. The identification, quantification, and control of regadenoson impurities are critical steps in the drug development and manufacturing process.