Integrated RP‐HPLC and LC–MS/MS Strategy for Stability‐Indicating Impurity Profiling and Degradant Identification of Doxecitine and Doxribtimine

ABSTRACT

A novel reverse phase‐liquid chromatography method was therefore developed and then validated for the separation and characterization of impurities and byproducts, and the degradation products of drugs doxecitine and doxribtimine were further identified using liquid chromatography–mass spectrometry method analysis. Here method optimization was carried out using the stress‐degraded samples along with the spiked impurity solutions. The chromatographic separation was achieved on a Waters X‐Bridge C18 column of dimensions (150 mm × 4.6 mm, 3.5 µm), which is equipped with a PDA detector. At a flow rate of 1.0 mL/min and a detection wavelength of 257 nm, an isocratic mobile phase of water was pH‐adjusted to 3.0 with formic acid and methanol (70:30, v/v). The method here demonstrated the satisfactory performance of parameters like accuracy, precision, and linearity for the drugs doxecitine, doxribtimine, and their four impurities. The forced degradation studies confirmed that the stability‐indicating nature of the method. The seven degradation products were successfully characterized using liquid chromatography–mass spectrometry method, and sensitivity parameters including like LOD and LOQ were adequately established. All the analytes exhibited strong linearity along with a correlation coefficient of 0.999, by confirming the reliability of the method for the quantitative analysis of doxecitine, doxribtimine, and the related substances.