title: Stability-indicating proton nuclear magnetic resonance spectroscopic assay method for furosemide in tablets and injections.
abstract: A simple, specific, and accurate proton nuclear magnetic resonance (1H-NMR) spectroscopic method has been developed for the identification and assay of furosemide and its degradation product, 4-chloro-5-sulfamoylanthranilic acid (CSA), in tablets and injections. Dissolution of the sample in D2O-NaOD resulted in a solution yielding the required separation among the resonance signals of furosemide, CSA, and tert-butyl alcohol, the internal standard. The mean +/- SD recovery values of furosemide and CSA from 10 synthetic formulations were 99.6 +/- 0.8 and 98.9 +/- 1.7%, respectively. Commercial tablets (6 lots) and injections (5 lots) of furosemide were assayed by the proposed method and found to contain 53.1-99.8% furosemide and 0.3-45.2% CSA.
authors.affiliation: U.S. Food and Drug Administration, New York Regional Laboratory, Brooklyn 11232.
authors.forename: G M
authors.initials: GM
authors.lastname: Hanna
authors.forename: C A
authors.initials: CA
authors.lastname: Lau-Cam
mesh_terms: D004355:Drug Stability; D005665:Furosemide / Q000032:analysis*; D007202:Indicators and Reagents; D007267:Injections; D009682:Magnetic Resonance Spectroscopy; D013607:Tablets; D062367:ortho-Aminobenzoates / Q000032:analysis
chemical_list: D007202:Indicators and Reagents; D013607:Tablets; D062367:ortho-Aminobenzoates; D005665:Furosemide; C010554:4-chloro-5-sulfamoylanthranilic acid