Study on the rate of epimerization of amoxicillin β-penicilloic acid to its α-form in aqueous solutions using high-performance liquid chromatography

Abstract Using automated high-performance liquid chromatography, a preliminary study on the rate of conversion of β-penicilloic acid to its α-form in aqueous solutions, using amoxicillin penicilloic acid as an example is described. An octadecyl-silica column eluted with 0.05 M potassium phosphate buffer solution (pH 5.9) with detection at 228 nm was used for this study. The conversion rate was found to follow pseudo first-order kinetics.