Solid-liquid Equilibrium Data of Amoxicillin and Hydroxyphenylglycine in Aqueous Media

The enzymatic synthesis of amoxicillin is catalyzed by Penicillin G Acylase (PGA). As byproducts, hydroxyphenylglycine and alcohol are also formed from hydrolytic reactions and antibiotic synthesis, respectively. The design of this process should be directed to promote the synthesis reaction. At the same time, it is necessary to reduce the hydrolytic reaction of amoxicillin through its crystallization or separation from the reaction medium. This work presents measurements of solid-liquid equilibrium data for amoxicillin and hydroxyphenylglycine in water at different temperatures (283.15 – 298.15 K), pH (5.5 – 7.5) and ethanol composition (0 – 70 wt.%). This information is relevant to determine the conditions that offer the lowest solubility for the antibiotic, favoring its separation and purification. All solubility data were obtained using an analytical method with indirect determination by UV spectroscopy. Ideal thermodynamic modeling was applied to describe the experimental solubility data sets.