Determination of the Related Substances of Dabigatran Etexilate by HPLC

OBJECTIVE To develop a method for determing the content of related substances of dabigatran etexilate. METHODS The condition of detection were: Agilent SB-C₁₈ column (250 mm×4.6 mm, 5 μm), the gradient mobile phase consisted of acetonitrile(A) and 0.2% ammonium acetate (B, adjust with glacial acetic acid to pH 4.4): 0-18 min, 90%→40%B; 18-30 min, 40%B. The flow rate was 1.0 mL·min^-1, the UV detection wavelength was 340 nm. RESULTS The resolution of dabigatran etexilate and relate substances was good. The calibration curves were linear in the range of 0.117 0-1.872 μg·mL^-1 for Impurity A (r=0.999 7); the calibration curves were linear in the range of 0.126 5-2.024 μg·mL^-1 for Impurity B (r=0.999 5); the calibration curves were linear in the range of 0.113 0-1.808 μg·mL^-1 for Impurity C (r=0.999 5); the calibration curves were linear in the range of 0.120 5-1.928 μg·mL^-1 for Impurity D (r=0.999 9); the calibration curves were linear in the range of 0.123?0-1.968 μg·mL^-1 for Impurity E (r=0.999 6). The average recoveries of Impurity A, Impurity B, Impurity C, Impurity D and Impurity E were 98.75%, 98.91%, 98.39%, 99.0% and 99.73% respectively; the RSD were 0.91%, 1.09%, 1.22%, 1.35% and 1.18%, respectively. CONCLUSION The correction factor method is viable to determine the content of related substances of dabigatran etexilate.