Use of Electrochemical Detection for HPLC Evaluation of Acid Hydrolysis of Sulfisoxazole

Milan Mokrý (mokry@faf.cuni.cz), Jiří Klimeš

Department of Pharmaceutical Chemistry and Drug Control, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic

Summary

HPLC with electrochemical detection was used to study acid hydrolysis of sulfisoxazole. The chromatographic conditions were elaborated on the reversed phase C₁₈ with a mixture of methanol and water (40:60; v/v) adjusted to pH 4.0 with perchloric acid as the mobile phase. The order of the reaction was determined; for the temperatures at which stability was examined the rate constants as well as the value of energy of activation were calculated. The identity of degradation products was verified by hydrodynamics voltammograms.