Nitrosamines are a class of compounds that can occur naturally in some foods and water, but they become a bigger concern in pharmaceuticals when levels exceed strict safety limits set by the FDA. In this case, the specific impurity was N-nitroso prazosin impurity C.
Manufacturing processes, certain raw materials, or even how drugs are stored over time can sometimes lead to these trace amounts forming. This isn’t the first time the industry has seen nitrosamine-related recalls — similar issues have appeared in other blood pressure drugs in past years, prompting tighter
