title: LC: analysis of photodegradation kinetics of nitazoxanide in pharmaceutical formulations.
abstract: Nitazoxanide is a new broad-spectrum, antiparasitic drug agent. The photodegradation of nitazoxanide was studied in order to investigate the degradation kinetics of this drug. The analyses of the degraded samples were performed by a stability-indicating liquid chromatographic method. The degradation was carried out in acetonitrile with coated tablets or oral suspension powder in quartz cells under UVC light at 254 nm. The kinetics parameters, such as order of reaction, rate constants, half-life (t(1/2)), and the time when 90% of the drug original concentration was left, were determined. The photodegradation of nitazoxanide for both pharmaceutical formulations in acetonitrile solution shows a zero-order kinetics under the applied experimental conditions. The obtained results confirm the reliability of the chromatographic method for determining the kinetics run of nitazoxanide in the presence of its degradation products. The present study reveals the photolability of the drug in solution. Thus, appropriated photoprotection is recommended during the manipulation of the drug.
authors.affiliation: Universidade Federal do Rio Grande do Sul, Faculdade de Farmácia, Programa de Pós-Graduação em Ciências Farmacêuticas, Porto Alegre, Rio Grande do Sul, Brazil. marcelodonadel@gmail.com
authors.forename: M D
authors.initials: MD
authors.lastname: Malesuik
authors.forename: H M L
authors.initials: HM
authors.lastname: Gonçalves
authors.forename: C S
authors.initials: CS
authors.lastname: Paim
authors.forename: E E S
authors.initials: EE
authors.lastname: Schapoval
authors.forename: M
authors.initials: M
authors.lastname: Steppe
mesh_terms: D000977:Antiparasitic Agents / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D007700:Kinetics; D009574:Nitro Compounds; D010782:Photolysis; D011208:Powders; D013607:Tablets; D013844:Thiazoles / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D000977:Antiparasitic Agents; D009574:Nitro Compounds; D011208:Powders; D013607:Tablets; D013844:Thiazoles; C041747:nitazoxanide