Meeting Report - Meeting report on protein particles and immunogenicity of therapeutic proteins: Filling in the gaps in risk evaluation and mitigation.
AUTHORS: John Carpenter, Barry Cherney, Anthony Lubinecki, Stacey Ma, Ewa Marszal, Anthony Mire-Sluis, Thomas Nikolai, Jeanne Novak, Jack Ragheb and Jan Simak.
Published in Biologicals 38 (2010): 602-611.
ABSTRACT:
The objective of this study was to evaluate microflow imaging (MFI) as a sensitive tool to detect and quantify subvisible particle formation during freeze-thawing of an IgG2 monoclonal antibody (mAb). Solutions of the protein formulated in 20 mM of histidine buffer (pH 5.5) were subjected to three freeze-thaw cycles and analyzed by MFI and size-exclusion chromatography (SEC). MFI showed increased particle numbers after each freeze-thaw cycle, whereas aggregates were not detected by SEC. Estimates of the total mass of particles formed revealed that monitoring of particle formation allows for the detection of protein aggregates comprising only hundredths of a percent of the total protein mass. Furthermore, differences in protein aggregation levels due to different formulations or different freeze-thawing protocols were resolved, even though protein aggregation could not be detected by SEC. To examine whether SEC and MFI-based estimations of total aggregate mass were in quantitative agreement, mAb was freeze-thawed in phosphate-buffered saline. This process created sufficient level of insoluble aggregates to be detected by SEC as a reduction in the monomer peak area in the chromatogram. There was good agreement between the loss of monomer detected by SEC and the total mass of subvisible particles detected by MFI. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci
KEY WORDS: protein aggregation; protein formulation; liquid chromatography; infrared spectroscopy; particle size.
The complete article can be found at:
http://www3.interscience.wiley.com/journal/121378778/abstract
Scientific Publication - High-Molecular-Weight Aggregates in Repackaged Bevacizumab
AUTHORS: Kahook MY, Liu L, Ruzycki P, Mandava N, Carpenter JF, Petrash JM, Ammar DA.
Published in Retina 30(6): 887-892.
IN THIS ARTICLE:
In comparison to SEC and Polyacrylamide Gel Electrophoresis methods...
"To quantify the number of particles between different syringes, the more sensitive MFI method was performed. This approach showed a substantially higher number of >1-μm particles in the material sourced from a CP (compounding pharmacy) when compared with material not prepared by a CP."
". . . Of all the analytical studies shown here, MFI is the only one sensitive enough to detect these larger particles because: 1) although micron-sized particles contain millions of proteins, they represent a trace amount of the total protein and would be nearly invisible by polyacrylamide gel electrophoresis; 2) the size of these particles would preclude them from entering the size exclusion chromatography column; and 3) in addition to protein, some of the particles could be resulting from nonprotein materials such as silicone oil from the syringes."
The complete article can be found at:
Journal Article: High-Molecular-Weight Aggregates in Repackaged Bevacizumab
Newsletter - "Staying Current" for BioPharmaceutical Formulation Scientists
The August 2010 issue highlights a number of articles addressing issues on subvisible particle characterization with many references to Brightwell's Micro-Flow Imaging (MFI) technology.
To download the August 2010 issue:
Staying Current - Aug 2010
OVERVIEW: Each day, new discoveries are being made in formulation science and process development of biotechnology-based therapeutics. The difficulty is staying current on all of the new developments. This monthly newsletter will keep you apprised of the most important advances in this critical field. Each article is selected for its relevance to formulation, drug delivery, and process development, as they apply to peptides, proteins, and vaccines. In addition to the complete reference and abstract, a detailed analysis of the importance and significance is provided.
PUBLISHERS: Legacy BioDesign LLC. www.legacybiodesign.com
