title: Analyzing insulin samples by size-exclusion chromatography: a column degradation study.
abstract: Investigating insulin analogs and probing their intrinsic stability at physiological temperature, we observed significant degradation in the size-exclusion chromatography (SEC) signal over a moderate number of insulin sample injections, which generated concerns about the quality of the separations. Therefore, our research goal was to identify the cause(s) for the observed signal degradation and attempt to mitigate the degradation in order to extend SEC column lifespan. In these studies, we used multiangle light scattering, nuclear magnetic resonance, and gas chromatography-mass spectrometry methods to evaluate column degradation. The results from these studies illustrate: (1) that zinc ions introduced by the insulin product produced the observed column performance issues; and (2) that including ethylenediaminetetraacetic acid, a zinc chelator, in the mobile phase helped to maintain column performance.
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, 80045.
authors.forename: Brandon M
authors.initials: BM
authors.lastname: Teska
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
authors.forename: Michael F
authors.initials: MF
authors.lastname: Wempe
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D002850:Chromatography, Gel; D004355:Drug Stability; D004492:Edetic Acid / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D061268:Insulin Lispro / Q000737:chemistry*; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D059748:Proteolysis; D012542:Scattering, Radiation; D013678:Technology, Pharmaceutical / Q000379:methods*; D015032:Zinc / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D061268:Insulin Lispro; D004492:Edetic Acid; D015032:Zinc
keywords: NMR spectroscopy; chelation; chromatography; mass spectrometry; surface chemistry