Evaluation of temperature, excipients impact on the primary structure of Ganirelix in an injectable formulation and comparison with Orgalutran® using MALDI‐TOF/TOF‐MS

Ganirelix is a linear polypeptide consisting of covalently bonded 10 amino acid residues. The amino acid sequence in a peptide determines the properties of the molecule. The slightest change in the primary structure (amino acid sequence) of therapeutic peptides can significantly impact its safety, efficacy, and immunogenicity. Hence, the primary structure analysis of therapeutic peptides is regarded as a critical quality attribute (CQA). A vast array of analytical techniques can be used to capture the primary structure of the peptide. In this study, we applied matrix-assisted laser desorption ionization (MALDI)/tandem time of flight mass spectroscopic (TOF/TOF MS) method to demonstrate the primary structure of Ganirelix in an injectable formulation. The apparent monoisotopic molecular mass of Ganirelix is 1,568.9 Da. The attained primary amino acid sequence of Ganirelix in temperature-stressed generic product matched with the theoretical sequence and showed homology with those of the reference listed drug (RLD).