4-(Methylamino)butanoic Acid / NMBA Starting material

4-(Methylamino)butyric acid, also known as N-Methyl-4-aminobutyric acid and 4-(Methylamino)butanoic acid, is an important amino acid–based intermediate widely used as a starting material in the synthesis of several active pharmaceutical ingredients (APIs) and fine chemicals. It has the molecular formula C5H11NO2, a molecular weight of 117.15 g/mol, and is associated with CAS No. 1119-48-8. As a secondary amine containing compound, this material can undergo nitrosation when exposed to nitrite sources under acidic or nitrosating conditions, potentially forming the nitrosamine impurity N-Nitroso-N-methyl-4-aminobutyric acid (NMBA).

Although 4-(Methylamino)butyric acid itself is not a nitrosamine, its potential to form NMBA makes it a critical precursor in global nitrosamine risk-management requirements, including USFDA, EMA, and ICH M7 expectations. The nitrosamine impurity NMBA is classified under the USFDA Carcinogenic Potency Categorization Approach (CPCA) as Potency Category 3, with an acceptable intake limit of 96 ng/day. As such, manufacturers using this starting material must evaluate nitrosation pathways, eliminate nitrite sources, and apply sensitive analytical testing (LC-MS/MS) to ensure NMBA is not formed or carried into the final product. 4-(Methylamino)butyric acid is used in the synthesis of various APIs, intermediates, and specialty chemicals, particularly where methylamino-functionalized chains are required. In pharmaceutical settings, its key relevance lies in its role as an NMBA precursor, requiring robust process controls and monitoring to ensure nitrosamine-free manufacturing.

At Manasa Life Sciences, we support manufacturers using 4-(Methylamino)butyric acid through comprehensive nitrosamine risk assessments, precursor evaluation, process optimization, and development of ultra-sensitive analytical methods for detecting NMBA at trace levels. Our solutions help ensure full regulatory compliance, strengthen impurity-control strategies, and support safe and high-quality drug development and commercial production.