title: Kinetics of hydrolysis of ceftazidime in aqueous solutions.
abstract: The kinetics of hydrolysis of ceftazidime in aqueous solutions at 323 K, 333 K, 343 K and 353 K over the pH-range (0.43-9.76) and at 295 K, 303 K and 308 K over the pH-range (9.17-13.16) has been investigated. The decomposition was followed by HPLC and UV spectral methods. The pH-rate profile was accounted for by the specific acid catalyzed reactions and also by assuming spontaneous water-catalyzed decomposition of molecule ceftazidime in various grade of dissociation. Various buffer substances were found to exhibit general acid and base catalysis of the degradation. Thermodynamic parameters of the reaction: energy, entropy and enthalpy of activation and the frequency factor for the specific rate constants were determined.
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, School of Medicine, Poznań, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Siwek
authors.forename: M
authors.initials: M
authors.lastname: Zajac
mesh_terms: D002442:Ceftazidime / Q000737:chemistry*; D002511:Cephalosporins / Q000737:chemistry*; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D013816:Thermodynamics
chemical_list: D002511:Cephalosporins; D002442:Ceftazidime