Insight into the degradation mechanism of cefixime under crystallization condition  

作　　者：Lingyu Wang Xiaona Li Yumin Liu DANDan Han Shiyuan Liu Teng Zhang Bo Yu Junbo Gong 

机构地区：[1]School of Chemical Engineering and Technology, Tianjin University

出　　处：《Chinese Journal of Chemical Engineering》2018年第7期1458-1467,共10页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(81361140344 and21376164);National High Technology Reseach and Development Program of China(863Program,2015AA021002);Major National Scientific Instrument Development Project(21527812)

摘　　要：The chemical stability of cefixime was determined by high-performance liquid chromatography （HPLC） under different conditions, including factors such as pH, solvents, initial concentration, temperature and additives. The degradation process follows the first-order kinetics. A pH-rate profile exhibits the U-shape and shows the maximum stability of cefixime at pH = 6. The stability in different pure solvents is ranked as acetone 〉 ethanol 〉 methanol 〉 water, while the degradation rate of cefixime exists a maximum at the ratio of 0.6 in water ＋ methanol mixtures. In addition, the degradation rate increases with the temperature increasing and the activation energy of degradation was found to be 27.078 kJ. mol- 1 in acetone ＋ water mixed solvents. The addition of different additives was proven to either inhibit or accelerate the degradation. The degradation products were analyzed using HPLC, LC-MS and infrared spectroscopy, and the possible degradation pathways in acid as well as alkaline environment were proposed to help us understand the degradation behavior of cefixime.The chemical stability of cefixime was determined by high-performance liquid chromatography(HPLC) under different conditions, including factors such as p H, solvents, initial concentration, temperature and additives.The degradation process follows the first-order kinetics. A p H-rate profile exhibits the U-shape and shows the maximum stability of cefixime at pH = 6. The stability in different pure solvents is ranked as acetone N ethanol N methanol N water, while the degradation rate of cefixime exists a maximum at the ratio of 0.6 in water + methanol mixtures. In addition, the degradation rate increases with the temperature increasing and the activation energy of degradation was found to be 27.078 k J·mol^(-1) in acetone + water mixed solvents. The addition of different additives was proven to either inhibit or accelerate the degradation. The degradation products were analyzed using HPLC, LC–MS and infrared spectroscopy, and the possible degradation pathways in acid as well as alkaline environment were proposed to help us understand the degradation behavior of cefixime.

关 键 词：Chemical stability Degradation kinetics DEGRADATION Mechanism Cefixime Additives 

分 类 号：O657.72[理学—分析化学] X703[理学—化学]