title: Identification of chlorothiazide and hydrochlorothiazide UV-A photolytic decomposition products.
abstract: Methanol solutions of hydrochlorothiazide and chlorothiazide were irradiated with fluorescent UV-A lamps in order to simulate degradation under normal conditions. The degradation products were identified by comparison to synthetic standards featuring electrospray ionization mass spectroscopy, ultraviolet spectroscopy, and high performance liquid chromatography. The standards were characterized by high resolution fast atom bombardment MS and 1H NMR. The photolysis of chlorothiazide resulted in photodehalogenation products exclusively, while the irradiation of hydrochlorothiazide primarily yielded photodehalogenation products with significant yields of photodehydrogenation products and minor amounts of thermal hydrolysis products.
authors.affiliation: Food and Drug Administration, Center for Drug Evaluation and Research, St. Louis, MO 63101, USA.
authors.forename: L K
authors.initials: LK
authors.lastname: Revelle
authors.forename: S M
authors.initials: SM
authors.lastname: Musser
authors.forename: B J
authors.initials: BJ
authors.lastname: Rowe
authors.forename: I C
authors.initials: IC
authors.lastname: Feldman
mesh_terms: D002740:Chlorothiazide / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006852:Hydrochlorothiazide / Q000737:chemistry*; D010777:Photochemistry; D013057:Spectrum Analysis; D014466:Ultraviolet Rays
chemical_list: D006852:Hydrochlorothiazide; D002740:Chlorothiazide