Evaluation of the Chemical Integrity of Beta-Lactam Antibiotics by Iodine-Based Assay

• 作者: Abraham Salois Ervin Palma Ethan Goolish Iris Perez Yuri Griko
• 来源期刊: 生物科学与医学(英文)
• 学科: 医学
• 关键词: AMOXICILLIN IODINE CHEMICAL INTEGRITY
• 年，卷（期）: 2015,（11）
• 页码范围: 91-99
• 页数: 9页
• 分类号: R73

摘要

One of the major problems associated with the therapeutic application of β-lactam antibiotics is their significant instability [1]-[3]. Analogs from that group are easily degraded in aqueous solutions and in solid state, which happens predominantly as a result of β-lactam ring chemical degradation. Because of this, the chemical integrity of β-lactam antibiotics must be closely monitored to meet FDA requirements. The original iodometric method based on visual detection of the end products of beta-lactamase hydrolysis that has been used to test beta-lactamase activity [4] was modified to quantitatively assess the amount of degraded product in amoxicillin. A UV-visible spectrophotometric method has been used, focusing on the ability of the products from the degradation of β-lactam analogs to absorb iodine from bulk solution, resulting in a significant reduction in the absorption spectra. Amoxicillin trihydrate tablets with different expiration dates and amoxicillin samples pre-loaded with known amounts of degraded amoxicillin have been used to generate a calibration curve and quantify the presence of degraded materials. Results show that the changes in the absorption spectra of iodine reagent directly correlate with the fraction of degraded β-lactam antibiotics, such as amoxicillin, in commercial products. The proposed assay might be as close as one step from simpler and cheaper methods of quantitative analysis of degraded β-lactam analogs, with estimated sensitivity in the range of 1% - 2%, which is better than the current FDA requirements.