The influence of pH, temperature and buffers on the degradation kinetics of cefetamet pivoxil hydrochloride in aqueous solutions.
The first-order hydrolysis kinetics of cefetamet pivoxil (CP) were investigated as a function of pH, temperature and buffers. The degradation was followed by HPLC. Buffer catalysis was observed in acetate and phosphate buffers. The pH-rate profiles for hydrolysis of cefetamet pivoxil were obtained at 333, 343, 353 and 363K. The pH-rate expression was k(pH)=kH+aH+ + kH2OkOH-aOH-, where kH+ and kOH- are the second-order rate constants (mol(-1)ls(-1)) for hydrogen ion activity and for hydroxyl ion activity respectively, and kH2O is the pseudo-first-order rate constant (s(-1)) for spontaneous reaction under the influence of water. The pH-rate profile was characteristically U-shaped. Maximum stability was observed in the pH region from 3 to 5.
Jelińska
Anna
A
Department of Pharmaceutical Chemistry, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznań, Poland. ajelinska@ap.edu.pl
Dobrowolski
Leszek
L
Oszczapowicz
Irena
I
D000900:Anti-Bacterial Agents / Q000737:chemistry; D002021:Buffers; D015296:Ceftizoxime / Q000031:analogs & derivatives* / Q000737:chemistry*; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
D000900:Anti-Bacterial Agents; D002021:Buffers; D012996:Solutions; D014867:Water; D015296:Ceftizoxime; C047445:cefetamet pivoxyl