Development of a validated stability-indicating HPLC- DAD method for dasabuvir and the characterization of its degradation products using LC-QToF-MS/MS

A stability-indicating HPLC-DAD method was developed and validated for the simultaneous determination of dasabuvir and its degradation products in the pharmaceutical formulation. The proposed method utilized a Symmetry (R) C18 (4.6 x 75 mm, 3.5 gm) column, and the mobile phase consisted of an isocratic elution of formic acid (0.1%) and acetonitrile (55:45, v/v), at a flow of 1 mL min-1; analytes were detected at 244 nm. Dasabuvir was submitted to different stress degradation conditions, such as acidic, alkaline, neutral, thermal, oxidative and photolytic, and the structural elucidation of degradation products was performed using LC-QToF-MS/MS. The HPLC-DAD stability-indicating method was validated for selectivity, linearity, limit of detection and quantification, accuracy, precision and robustness, according to ICH guidelines. Dasabuvir produced two degradation products (DP1 and DP2) from the alkaline stress conditions, which were characterized in negative ion mode. Dasabuvir was linear in the range 9.78 to 136.92 gg mL-1, and DP1 and DP2 were linear in the range 2.9 to 20.2 gg mL-1 and 1.3 to 14.9 gg mL-1, respectively. The recovery ranged between 99.16 and 100.86%, while precision ranged from 1.02 to 2.89%. As the method can effectively separate the dasabuvir from its degradation products and quantitate them, it may be employed as a stability-indicating method for the pharmaceutical formulation.