Displaying 5 results of Tiopronin Impurities Tiopronin is a medication used to treat cystinuria, a rare genetic disorder that causes the formation of kidney stones. Tiopronin impurities refer to any substances present in a sample of tiopronin that are not the active pharmaceutical ingredient. These impurities can affect the safety and efficacy of the medication and must be closely monitored and controlled during production. Regulatory agencies have strict guidelines for acceptable levels of tiopronin impurities in pharmaceutical products.