The importance of interfaces in protein drug delivery - why is protein adsorption of interest in pharmaceutical formulations?

INTRODUCTION: In the area of peptide and protein drug products, interfaces are present as part of the basic liquid formulation, when freeze-dried formulations are reconstituted and when particulate delivery systems are prepared. Proteins are known to interact with these interfaces, and the effects seen are often irreversible adsorption and structural changes. AREAS COVERED: This review focuses on the ways in which peptides and proteins interact with surfaces and interfaces, and the effect these interactions have on the stability and safety of the active protein in pharmaceutical formulations. It illustrates, through examples, what can be determined by an adsorption study, and what can change when either the protein or the interfaces are modified. Last but not least, it addresses the value of these studies. The reader will gain an update on the basics of protein adsorption, with a focus on pharmaceutically relevant interfaces and recent advances in the field. EXPERT OPINION: Protein adsorption is widely studied; however, a more unified approach is still needed, especially on the adsorption of pharmaceutically relevant proteins, modified proteins and surfaces.