Basic regulatory science behind drug substance and drug product specifications of monoclonal antibodies and other protein therapeutics

In this review,we focus on providing basics and examples for each component of the protein therapeutic specifications to interested pharmacists and biopharmaceutical scientists with a goal to strengthen understanding in regulatory science and compliance.Pharmaceutical specifications comprise a list of important quality attributes for testing,references to use for test procedures,and appropriate acceptance criteria for the tests,and they are set up to ensure that when a drug product is administered to a patient,its intended therapeutic benefits and safety can be rendered appropriately.Conformance of drug substance or drug product to the specifications is achieved by testing an article according to the listed tests and analytical methods and obtaining test results that meet the acceptance criteria.Quality attributes are chosen to be tested based on their quality risk,and consideration should be given to the merit of the analytical methods which are associated with the acceptance criteria of the specifications.Acceptance criteria are set forth primarily based on efficacy and safety profiles,with an increasing attention noted for patient-centric specifications.Discussed in this work are related guidelines that support the biopharmaceutical specification setting,how to set the acceptance criteria,and examples of the quality attributes and the analytical methods from 60 articles and 23 pharmacopeial monographs.Outlooks are also explored on process analytical technologies and other orthogonal tools which are on-trend in biopharmaceutical characterization and quality control.

Elucidating the Degradation Pathways of Human Insulin in the Solid State

While there have been significant advances in the development of peptide oral dosage forms in recent years,highlighted by the clinical and commercial success of approved peptides such as Rybelsus®,there remain several barriers in the way of broad range applicability of this approach to peptide delivery.One such barrier includes the poor physical and chemical stability inherent to their structures,which persists in the solid state although degradation typically occurs at different rates and via different pathways in comparison to the solution state.Using insulin as a model peptide,this work sought to contribute to the development of analytical techniques for investigating common insulin degradation pathways.Chemically denatured,deamidated and aggregated samples were prepared and used to benchmark circular dichroism spectroscopy,reverse phase HPLC and size exclusion chromatography methods for the investigation of unfolding,chemical modifications and covalent aggregation of the insulin molecule respectively.Solid state degraded samples were prepared by heating insulin powder at 60°C and 75%relative humidity for 1,3,5 and 7 d,and the degradation profiles of the samples were evaluated and compared with those observed in solution.While no unfolding was observed to occur,significant deamidation and covalent aggregation were detected.Reductive disulfide bond cleavage using dithiothreitol allowed for separation of the insulin A-and B-chains,offering a facile yet novel means of assessing the mechanisms of deamidation and covalent aggregation occurring in the solid state.