N-Nitroso Desmethyl Orphenadrine (NMOA)

N-Nitroso N-Desmethyl Orphenadrine (NMOA) is a genotoxic and potentially carcinogenic nitrosamine impurity associated with Orphenadrine, an anticholinergic muscle relaxant used for the management of acute musculoskeletal pain and related conditions. Chemically, it is described as N-methyl-N-(2-(phenyl(o-tolyl)methoxy)ethyl)nitrous amide, reflecting nitrosation of the N-methyl secondary amine in the desmethyl metabolite/intermediate of Orphenadrine. CAS No: 3028194-83-1; Molecular Formula: C17H20N2O2; Molecular Weight: 284.36g/mol.

This impurity can form during API synthesis, formulation steps, or degradation, particularly in the presence of nitrite contaminants, acidic conditions, oxidative environments, or other nitrosation-promoting factors. N-Nitroso N-Desmethyl Orphenadrine is classified under the USFDA Carcinogenic Potency Categorization Approach (CPCA) as Potency Category 1, with a default acceptable intake limit of 26.5 ng/day, the standard regulatory limit.

At Manasa Life Sciences, we support pharmaceutical manufacturers in managing and mitigating NMOA by identifying nitrosation-susceptible steps within the synthetic route, assessing nitrite and amine precursor contributions from raw materials and excipients, and implementing strong nitrosation-control strategies. We also develop and validate high-sensitivity analytical methods, including LC-MS/MS and HRMS, for precise trace-level detection. Through these services, we strengthen nitrosamine-risk assessment bases, enhance GMP compliance, and help ensure product quality and patient safety throughout drug development and commercial manufacturing.