title: Kinetic study and mechanism of Niclosamide degradation.
abstract: A spectrophotometric kinetic study of Niclosamide alkaline degradation as a function of drug concentration, alkaline concentration and temperature has been established utilizing double divisor-ratio spectra spectrophotometric method. The developed method allowed determination of Niclosamide in presence of its alkaline degradation products; namely; 2-chloro-4-nitro aniline (DEG I) and 5-chloro salicylic acid (DEG II) with characterization of its degradation mechanism. It was found that degradation kinetic of Niclosamide followed pseudo-first order under the established experimental conditions with a degradation rate constant (k) of 0.0829 mol/h and half life (t1/2) of 8.35 h. The overall degradation rate constant as a function of the temperature under the given conditions obeyed Arrhenius equation where the activation energy was calculated to be 3.41 kcal/mol.
authors.affiliation: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El-Aini, 11562 Cairo, Egypt.
authors.forename: Hala E
authors.initials: HE
authors.lastname: Zaazaa
authors.affiliation: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Beni-Suef University, Al-Shaheed Ahmed Hegazy, 26111 Beni-Suef, Egypt.
authors.forename: Maha M
authors.initials: MM
authors.lastname: Abdelrahman
authors.affiliation: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Beni-Suef University, Al-Shaheed Ahmed Hegazy, 26111 Beni-Suef, Egypt.
authors.forename: Nouruddin W
authors.initials: NW
authors.lastname: Ali
authors.affiliation: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Beni-Suef University, Al-Shaheed Ahmed Hegazy, 26111 Beni-Suef, Egypt. Electronic address: maimanamagdy@yahoo.com.
authors.forename: Maimana A
authors.initials: MA
authors.lastname: Magdy
authors.affiliation: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr-El-Aini, 11562 Cairo, Egypt.
authors.forename: M
authors.initials: M
authors.lastname: Abdelkawy
mesh_terms: D007700:Kinetics; D013058:Mass Spectrometry; D009534:Niclosamide / Q000737:chemistry*; D015203:Reproducibility of Results; D012972:Sodium Hydroxide / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013696:Temperature
chemical_list: D012972:Sodium Hydroxide; D009534:Niclosamide
keywords: Degradation; Double divisor-ratio spectra spectrophotometry; Kinetic; Niclosamide