Study on degradation kinetics of epalrestat in aqueous solutions and characterization of its major degradation products under stress degradation conditions by UHPLC-PDA-MS/MS

Publication date: Available online 15 August 2018Source: Journal of Pharmaceutical AnalysisAuthor(s): Suyan Liu, Hong Sun, Xun Gao, Zhili Xiong, Zhonggui He, Longshan ZhaoAbstractDrug stability is closely related to drug safety and needs to be considered in the process of drug production, package and storage. To investigate the stability of epalrestat, a carboxylic acid derivative, a reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed in this study and applied to analyze the degradation kinetics of epalrestat in aqueous solutions in various conditions, such as different pH, temperatures, ionic strengths, oxidation and irradiation. The calibration curve was A = 1.6×105C − 1.3×103 (r = 0.999) with the liner range of 0.5–24 μg/mL, the intra-day and inter-day precision was less than 2.0%, as was the repeatibility. The average accuracy for different concentrations was less than 98.5%, indicating that perfect recoveries were achieved. Degradation kinetics parameters such as degradation rate constants (k), activation energy (Ea) and shelf life (t0.9) under different conditions were calculated and discussed. The results indicated that the degradation behaviour of epalrestat was pH-dependent and the stability of epalrestat decreased with the rising irradiation and ionic strength; however, it was more stable in neutral and alkaline conditions as well as lower temperature. The results showed that the degradation kinetics of epalrestat followe...
Source: Journal of Pharmaceutical Analysis - Category: Drugs & Pharmacology Source Type: research