Preparation, isolation, and characterization of dimeric degradation products of the 1β-methylcarbapenem antibiotic, ertapenem

Dimeric degradates of ertapenem, a novel broad-spectrum 1 beta -methyl carbapenem antibiotic currently in development, have been prepared by controlled degradation of the bulk drug substance in concentrated solutions and isolated by preparative HPLC. The degradates were characterized by LC/MS and NMR and result from various bimolecular reactions of the carbapenem leading to dimers and dehydrated dimers. The development of selective degradation procedures was critical in facilitating isolation of the degradates, and provided a better understanding of the degradation process. This report will focus on the development of preparative chromatographic methods for isolation of these highly unstable compounds.