Peptide stability needs a context
A stability finding belongs to a defined molecule, formulation, method and set of test conditions.
What a model experiment showed
Li and colleagues compared seven model peptides in solution and in freeze-dried formulations under accelerated laboratory conditions. They studied deamidation, a chemical change involving an amino-acid side chain. Nearby amino-acid residues affected the rate differently in the two settings.
Why the setting matters
The lesson is about interpretation: sequence and physical environment can matter to a measured stability result. This experiment does not assign a shelf life to an unrelated peptide or a commercially supplied vial. Its deliberately stressed conditions are not handling instructions.
What would support a shelf-life claim?
FDA Q7 guidance calls for an ongoing stability programme, suitable analytical methods and samples in containers representing the marketed packaging. A stability claim should identify what was measured and under which conditions. We do not provide reconstitution, storage recipes or administration protocols.
Follow the sources
- 1Effect of N-1 and N-2 residues on peptide deamidation rate in solution and solid state Primary laboratory study, 2006
- 2FDA: Q7A Good Manufacturing Practice Guidance, stability monitoring FDA quality guidance