title: Artifacts Generated During Azoalkane Peroxy Radical Oxidative Stress Testing of Pharmaceuticals Containing Primary and Secondary Amines.
abstract: We report artifactual degradation of pharmaceutical compounds containing primary and secondary amines during peroxy radical-mediated oxidative stress carried out using azoalkane initiators. Two degradation products were detected when model drug compounds dissolved in methanol/water were heated to 40°C with radical initiators such as 2,2'-azobis(2-methylpropionitrile) (AIBN). The primary artifact was identified as an α-aminonitrile generated from the reaction of the amine group of the model drug with formaldehyde and hydrogen cyanide, generated as byproducts of the stress reaction. A minor artifact was generated from the reaction between the amine group and isocyanic acid, also a byproduct of the stress reaction. We report the effects of pH, initiator/drug molar ratio, and type of azoalkane initiator on the formation of these artifacts. Mass spectrometry and nuclear magnetic resonance were used for structure elucidation, whereas mechanistic studies, including stable isotope labeling experiments, cyanide analysis, and experiments exploring the effects of butylated hydroxyanisole addition, were employed to support the degradation pathways.
authors.affiliation: Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania 19486.
authors.forename: Marcela
authors.initials: M
authors.lastname: Nefliu
authors.affiliation: Pfizer Inc., Analytical Research & Development, Eastern Point Road, Groton, Connecticut 06340.
authors.forename: Todd
authors.initials: T
authors.lastname: Zelesky
authors.affiliation: Eli Lilly and Company, Lilly Research Laboratories, Indianapolis, Indiana 46285.
authors.forename: Patrick
authors.initials: P
authors.lastname: Jansen
authors.affiliation: Pfizer Inc., Analytical Research & Development, Eastern Point Road, Groton, Connecticut 06340.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Sluggett
authors.affiliation: Pfizer Inc., Analytical Research & Development, Eastern Point Road, Groton, Connecticut 06340. Electronic address: chris.foti@gilead.com.
authors.forename: Christopher
authors.initials: C
authors.lastname: Foti
authors.affiliation: Eli Lilly and Company, Lilly Research Laboratories, Indianapolis, Indiana 46285; Baertschi Consulting, LLC, Carmel, Indiana 46033.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Baertschi
authors.affiliation: Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania 19486.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Harmon
mesh_terms: D000588:Amines / Q000737:chemistry*; D016477:Artifacts; D003485:Cyanates / Q000737:chemistry; D005557:Formaldehyde / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D006856:Hydrogen Cyanide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D000432:Methanol / Q000737:chemistry; D009570:Nitriles / Q000737:chemistry; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D010545:Peroxides / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000588:Amines; D003485:Cyanates; D005609:Free Radicals; D009570:Nitriles; D010545:Peroxides; D014867:Water; D005557:Formaldehyde; D006856:Hydrogen Cyanide; C005057:isocyanic acid; D000432:Methanol
keywords: artifacts; autoxidation; chemical stability; degradation products; forced degradation; free radicals; mass spectrometry; oxidation; stability; strecker reaction; stress testing