Our client, a start-up biotechnology company was preparing the filing of a new promising API. The drug substance contained 14 impurities in the range of 0.05 to 0.3 % (a/a). The structure of most of the impurities was unknown and required unequivocal identification.

Based on the customer's priorities, a plan for the preparative isolation and subsequent structure elucidation of the impurities was developed. Using an orthogonal approach with consecutive preparative and semi-preparative HPLC, the impurities were enriched and isolated. Using sophisticated two-dimensional NMR experiments, mass spectrometry and FTIR our experts were able to elucidate the structure of these impurities with molecular weights of up to 900 g/mol.

Detailed structure elucidation reports for all impurities were submitted on-time. In addition, the elucidation of the structure of some of the impurities brought deeper insight into hitherto unknown side-reactions that allowed major improvements in the chemical process.