Limaprost is a medication used to treat peripheral arterial disease. Limaprost impurities refer to any impurities or byproducts that may be present in the drug substance or drug product during manufacturing or storage. These impurities can have a negative impact on the quality, safety, and efficacy of the medication and therefore need to be closely monitored and controlled. Analytical methods are used to identify and quantify these impurities to ensure compliance with regulatory requirements.