Related impurities in peptide medicines

Systematic classification of impurities in synthetic peptides by origin: synthesis, degradation of the peptide, and interaction with excipients.

Key points

• Synthesis impurities arise mainly from incomplete couplings (deletions), insertions and racemisation.
• Degradation products form via succinimide and diketopiperazine formation and oxidation, among other routes.
• Controlling these impurities matters not only for medicines but also for research, since by-products can influence the results of biological assays.

Assessment

Foundational work on why a purity figure alone is not enough. Our batch reports therefore list minor peaks individually. More in the article Typical impurities.