title: Do not drop: mechanical shock in vials causes cavitation, protein aggregation, and particle formation.
abstract: Industry experience suggests that g-forces sustained when vials containing protein formulations are accidentally dropped can cause aggregation and particle formation. To study this phenomenon, a shock tower was used to apply controlled g-forces to glass vials containing formulations of two monoclonal antibodies and recombinant human growth hormone (rhGH). High-speed video analysis showed cavitation bubbles forming within 30 μs and subsequently collapsing in the formulations. As a result of echoing shock waves, bubbles collapsed and reappeared periodically over a millisecond time course. Fluid mechanics simulations showed low-pressure regions within the fluid where cavitation would be favored. A hydroxyphenylfluorescein assay determined that cavitation produced hydroxyl radicals. When mechanical shock was applied to vials containing protein formulations, gelatinous particles appeared on the vial walls. Size-exclusion chromatographic analysis of the formulations after shock did not detect changes in monomer or soluble aggregate concentrations. However, subvisible particle counts determined by microflow image analysis increased. The mass of protein attached to the vial walls increased with increasing drop height. Both protein in bulk solution and protein that became attached to the vial walls after shock were analyzed by mass spectrometry. rhGH recovered from the vial walls in some samples revealed oxidation of Met and/or Trp residues.
authors.affiliation: Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado.
authors.forename: Theodore W
authors.initials: TW
authors.lastname: Randolph
authors.forename: Elise
authors.initials: E
authors.lastname: Schiltz
authors.forename: Donn
authors.initials: D
authors.lastname: Sederstrom
authors.forename: Daniel
authors.initials: D
authors.lastname: Steinmann
authors.forename: Olivier
authors.initials: O
authors.lastname: Mozziconacci
authors.forename: Christian
authors.initials: C
authors.lastname: Schöneich
authors.forename: Erwin
authors.initials: E
authors.lastname: Freund
authors.forename: Margaret S
authors.initials: MS
authors.lastname: Ricci
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
authors.forename: Corrine S
authors.initials: CS
authors.lastname: Lengsfeld
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis / Q000378:metabolism*; D004349:Drug Packaging / Q000592:standards*; D019382:Human Growth Hormone / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism*; D010316:Particle Size; D066329:Protein Aggregates / Q000502:physiology; D011994:Recombinant Proteins / Q000032:analysis / Q000378:metabolism; D013314:Stress, Mechanical
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D066329:Protein Aggregates; D011994:Recombinant Proteins; D019382:Human Growth Hormone
keywords: oxidation; particle size; protein aggregation; protein formulation; simulations; stability