Publication Date:
2012-05-31
Description:
The degradation kinetics of cloxacillin sodium (CS) under real production conditions was determined using high-performance liquid chromatography (HPLC). Degradation in methanol (MeOH) follows zero-order kinetics. The introduction of water kept the degradation order but decreased the rate constant, while butyl acetate (BA) accelerated the degradation and shifted the kinetics to first order. In the MeOH/BA system, the pH-dependent degradation rate generally increased when increasing the pH, except for a distinct drop at about pH 6.5. In aqueous solution, the effect of temperature was determined and the apparent activation energy of degradation was found to be 80.34 ± 5.88 kJ mol –1 . The degradation products were analyzed using HPLC, mass spectrometry, and infrared spectroscopy, and a pathway toward cloxalloic acid via cloxacilloic acid as intermediate is proposed. The degradation of cloxacillin sodium, an important antibiotic, was investigated in detail under real production conditions, i.e. other than those of storage or waste treatment. The effects of pH, initial concentration, and temperature on the degradation were studied, and a degradation pathway in aqueous solution is also proposed.
Print ISSN:
0930-7516
Electronic ISSN:
1521-4125
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Permalink
