Regulatory Guidelines for the Analysis of Therapeutic Peptides and Proteins

Peptides and proteins have become increasingly important in the treatment of various diseases, including infections, metabolic disorders, and cancers. Over the past decades, the number of approved peptide- and protein-based drugs has grown significantly, now accounting for about 25% of the global pharmaceutical market. This increase has been recorded since the introduction of the first therapeutic peptide, insulin, in 1921. Therapeutic peptides and proteins offer several advantages over small molecule drugs, including high specificity, potency, and safety; however, they also face challenges related to instability in liquid formulations. To address this issue, numerous formulation techniques have been developed to enhance their stability. In either state, physical and chemical characterization of the peptide or protein of interest is crucial for ensuring the identity, purity, and activity of these therapeutic agents. Regulatory bodies such as the FDA, ICH, and EMA have established guidelines for the analysis, stability testing, and quality control of peptides and biologics to ensure the safety and effectiveness of these drugs. In the present review, these guidelines and the consequences thereof are summarized and provided to support the notion of developing tailored bioanalytical workflows for each peptide or protein drug.