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.

Ceftazidime↗

PubMedDate not supplied

The influence of carbohydrates and polyhydric alcohols on the stability of ceftazidime in aqueous solution.

The kinetics of degradation of ceftazidime in aqueous solutions containing various carbohydrates (glucose and fructose) or polyhydric alcohols (sorbitol and mannitol) was investigated over the pH range 9.92-10.93 at 35 degrees C. A relationship between the degradation rate and the hydroxy compound concentration was observed at each pH studied, and the rate-accelerating effect of the compounds was directly proportional to the hydroxide ion activity.

Carbohydrates↗

PubMedDate not supplied

The mechanism of ceftazidime degradation in aqueous solutions.

Degradation of ceftazidime in aqueous solutions was studied at 298 K in acidic, basic and neutral conditions. The subsequent stage of hydrolysis involved the hydrolysis of the group at C-3, opening of the beta-lactam ring, and epimerization at C-6 or C-7. The decomposition of ceftazidime and the formation and identification of product C (pyridine) was followed by HPLC.

Ceftazidime↗