Author Archives: Nadine M. Ritter

Recommendations for Cell Banks Used in GXP Assays

Cells and cell-derived reagents form the basis of an operationally challenging class of test methods used in execution of product potency testing (stability and lot release), assessments of pharmacokinetic/ pharmacodynamic (PK/PD) profiles, detection of antidrug antibodies (ADAs) or neutralizing antibodies (NAB), and characterization and comparability testing of biopharmaceutical products. Frequently, cell-based assays provide the only measurement of the tertiary/quaternary structure of each batch of product at the time of lot release and during stability testing to assist in determining product…

Distinctions Between Analytical and Bioanalytical Test Methods

Analytical methods used for characterization, release, and stability testing of biotechnological/biological products are often automatically referred to as “bioanalytical” methods by some in the field. Many times the term is used to distinguish between test methods applied to small-molecule chemical products and those for macromolecular, biologically based products. It seems sensible enough: We use analytical methods to test chemical pharmaceutical products, so aren’t test methods used for biopharmaceutical products therefore bioanalytical methods? Any way, who cares whether the term is…

Stability Considerations for Biopharmaceuticals: Overview of Protein and Peptide Degradation Pathways

To ensure product safety and efficacy, protein therapeutics must meet defined quality characteristics immediately after manufacture as well at the end of their designated shelf lives. Many physical and chemical factors can affect the quality and stability of biopharmaceutical products, particularly after long-term storage in a container–closure system likely to be subject to variations in temperature, light, and agitation with shipping and handling. Compared with traditional chemical pharmaceuticals, proteins are considerably larger molecular entities with inherent physiochemical complexities, from their…