Decomposition kinetics of erythromycin A in acidic aqueous solutions

Abstract The decomposition of the antibiotic, erythromycin A, in acidic aqueous solutions has been investigated by means of a high-performance liquid chromatographic assay with ultraviolet detection at 215 nm. During decomposition erythromycin A is in equilibrium with erythromycin A enol ether and simultaneously erythromycin A is directly converted to anhydroerythromycin A. The calculations of the observed rate coefficients of the partial reactions ( k 1 , k 2 and k 3 ) were performed using a multiparameter fitting program present in the BMDP statistical software. The decomposition kinetics have been studied as a function of the type and concentration of the buffer, ionic strength, pH and temperature.