A Checklist For Risk Assessment Of Nitrosamine Impurities In Oral Solid Dose Drugs By Amol Galande, Ajay Pazhayattil, and Sanjay Sharma Nitrosamine impurities such as N-nitrosodimethylamine (NDMA) are being identified in high-volume drug products such as valsartan, losartan, irbesartan, and ranitidine at levels well above the acceptable daily intake limits. The credit for identifying the higher NDMA levels goes to an independent pharmacy 1 that tests every batch it dispenses, exposing limitations in drug substance and drug product post-approval change assessment and analysis requirements at pharmaceutical manufacturing organizations. Certain continuous process improvement changes (for example, Patent # WO/2011/124655, improved process for preparing valsartan) were deemed as the root cause for the higher amounts of NDMA observed. The issue has resulted in the largest product recalls in recent history, affecting brand and generic products alike. The outcome is a reminder to the industry that lean manufacturing efficiency changes can adversely affect the patient if they do not rely on a sound pharmaceutical science-based technical team performing a 360-degree risk assessment. A rapid reconciliation was required from the manufacturing industry since such incidents raise questions about ICH Q12