Main degradation products of dabigatran etexilate evaluated by LC-UV and LC-ESI-MS, degradation kinetics and in vitro cytotoxicity studies

Abstract

The present study reports the stability profile of an antithrombotic drug: dabigatran etexilate (DAB). The drug was subjected to thermal degradation at 60 °C and products formed were investigated by liquid chromatography-UV (LC-UV) and liquid chromatography-mass spectrometry (LC-ESI-MS). Chromatographic separation of the degradation products was performed on a GL Sciences Inc. Inertsil ODS-2 column (250 mm × 4.6 mm i.d., with a particle size of 5 µm and pore size of 110 Å) with mobile phase consisting of acetonitrile and ammonium acetate buffer (pH 5.5; 10 mmol L−1 ) (65:35, v/v) pumped at 1.0 mL min−1 flow rate. Column temperature was set at 30 °C and detection at 225 nm using a UV detector. LC-UV method previously validated was extended to LC-ESI-MS for the characterization of the degradation products (DP-01 and DP-02) formed, without complicated isolation or purification processes, based on retention times and confirmation of molecular weight. Degradation kinetics of DAB was also evaluated and could be described as a first-order process (R2 = 0.9900). Furthermore, no evidence of cytotoxicity in human mononuclear cells was observed for DAB degraded samples.