Liquid Chromatographic Method Development for Forced Degradation Products of Dabigatran Etexilate: Characterisation and In Silico Toxicity Evaluation

Abstract

A simple and accurate UHPLC method was developed for Dabigatran etexilate (DAB) using Acquity CSH C18 (100 mm × 2.1 mm × 1.7 µm) column with mobile phase containing ammonium acetate (pH 5.0) and methanol in gradient program. This method was used to study the forced degradation products of DAB. The drug was found to degrade in all hydrolytic and oxidative conditions resulting in formation of four major degradation products (DP1 to DP4). DAB and its degradation products were well separated using the proposed method. The degradation products were characterized using LC-Q-TOF/ESI/MS/MS and accurate mass measurements for obtaining the structural information. The degradation pathway leading to the formation of the degradation products was also proposed. In silico tools like TOPKAT and DEREK software were used to evaluate the toxicity associated with DAB and its degradation products. The developed method was validated as per ICH Q2 (R1) guidelines. The method showed linear response over a concentration range of 45–105 µg mL⁻¹ with correlation coefficient of 0.9998. The accuracy of the method was observed within the acceptable limits of 98–102 %. The precision of the method was good as indicated by %RSD values less than 1.0. The proposed method was found to be robust when deliberate changes were made in pH of buffer, column temperature and flow rate of the mobile phase. The developed method finds its application as a stability indicating assay method for the determination of DAB.