title: Characterization of Nanoparticle Tracking Analysis for Quantification and Sizing of Submicron Particles of Therapeutic Proteins.
abstract: Submicron particles may play important roles in therapeutic protein product quality, stability, and adverse effects in patients. However, quantitation of these particles has been challenging. Nanoparticle tracking analysis (NTA) is capable of both sizing and counting submicron particles. We investigated the effects of product and instrument parameters on NTA results for nanoparticle standards and therapeutic protein samples. To obtain proper particle size distributions, complete tracking numbers of at least 200 and 400 were required for latex nanobeads and protein nanoparticles, respectively. In addition, when set at suboptimal values, the minimum expected particle size parameter led to inaccurate sizing and counting for all particles types investigated. A syringe pump allowed for higher sampling volumes, and results were reproducible for nanoparticle sizing and counts at flow rates ≤7 μL/min. Finally, because therapeutic protein products are being formulated at relatively high protein concentrations, we investigated the effects of protein concentration on nanoparticle characterization. With high protein concentrations, nanoparticle sizing was not affected, whereas particle concentrations were significantly reduced. Linear relationships between particle count and dilution factor were obtained when a high protein concentration formulation was diluted into particle-free solutions at the same protein concentrations, but not when dilutions were made into buffer.
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045.
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Krueger
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045.
authors.forename: James G
authors.initials: JG
authors.lastname: Barnard
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045.
authors.forename: Wei
authors.initials: W
authors.lastname: Qi
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, 80045.
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000295:instrumentation / Q000379:methods*; D016503:Drug Delivery Systems; D004355:Drug Stability; D006046:Gold / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D007840:Latex / Q000737:chemistry; D053768:Metal Nanoparticles / Q000032:analysis* / Q000737:chemistry; D008956:Models, Chemical; D054118:Nanospheres / Q000032:analysis* / Q000737:chemistry; D009391:Nephelometry and Turbidimetry; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D066329:Protein Aggregates; D055550:Protein Stability; D011506:Proteins / Q000009:adverse effects / Q000032:analysis* / Q000737:chemistry; D011786:Quality Control; D015203:Reproducibility of Results; D012212:Rheology; D012709:Serum Albumin / Q000009:adverse effects / Q000032:analysis / Q000737:chemistry; D000075462:Serum Albumin, Human
chemical_list: C422455:ALB protein, human; D007840:Latex; D004364:Pharmaceutical Preparations; D066329:Protein Aggregates; D011506:Proteins; D012709:Serum Albumin; D006046:Gold; D000075462:Serum Albumin, Human
keywords: analysis; light scattering; nanoparticles; nanotechnology; particle size; physical characterization; protein aggregation; protein formulation; proteins