el-Gindy Alaa, Hadad Ghada M, Mahmoud Waleed M M
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt.
J Pharm Biomed Anal. 2007 Jan 4;43(1):196-203. doi: 10.1016/j.jpba.2006.07.001. Epub 2006 Aug 9.
High performance liquid chromatographic (HPLC) method is presented for the determination of etofibrate (EF) and its hydrolysis products. The method was based on HPLC separation of EF from its hydrolysis products using cyanopropyl column at ambient temperature with mobile phase consisting of acetonitrile-10 mM potassium dihydrogen phosphate, pH was adjusted to 4.1 using phosphoric acid (50:50, v/v). Quantitation was achieved with UV detection at 221 nm based on peak area. The flow rate was 1.5 ml min(-1). The proposed method was used to investigate the kinetics of acidic hydrolysis process of EF at different temperatures and the apparent pseudo first-order rate constant, half-life and activation energy were calculated. The kinetics of alkaline hydrolysis process of EF using 0.01 M sodium hydroxide at different temperatures cannot be studied as the drug is rapidly hydrolyzed in alkaline medium. The pH-rate profile of hydrolysis of EF in Britton-Robinson buffer solutions within the pH range 2-10 were studied.
本文介绍了一种用于测定依托贝特（EF）及其水解产物的高效液相色谱（HPLC）方法。该方法基于在室温下使用氰丙基柱，以乙腈-10 mM磷酸二氢钾为流动相（用磷酸将pH调节至4.1，体积比为50:50），从其水解产物中分离出EF。基于峰面积，通过在221 nm处进行紫外检测实现定量分析。流速为1.5 ml min⁻¹。所提出的方法用于研究EF在不同温度下的酸性水解过程动力学，并计算了表观伪一级速率常数、半衰期和活化能。由于该药物在碱性介质中迅速水解，因此无法研究EF在不同温度下使用0.01 M氢氧化钠的碱性水解过程动力学。研究了EF在pH范围为2-10的Britton-Robinson缓冲溶液中的水解pH-速率曲线。
