Forced Degradation Studies of Dobutamine and Isolation, Identification, and Characterization of Potential Degradation...

Dobutamine (DB) is a β1-adrenergic agonist with weak β2 activity and α1 selective activity, which is used clinically in cases of cardiogenic shock. Most of the available literature methods for DB that are LCMS incompatible have limitations for the identification of impurities. The current study describes forced degradation studies of DB and the identification of impurities by mass analysis, assigning structure to the major degradant, and the development and validation of an LCMS-compatible UPLC method. Impurity A (dopamine) highly polar impurity listed in the dopamine US Pharmacopeial Monograph, was retained in the developed method without an ion pair reagent. The method has been developed using Waters Acquity UPLC system equipped with Acquity UPLC HSS PFP column (2.1 mm × 100 mm, 1.8 μ), 0.05% TFA in water:ACN (95:5 %v/v) as Mobile Phase A, and 0.05% TFA in water:ACN (5:95 %v/v) as Mobile Phase B using a gradient program. DB degradation behavior was studied by subjecting it to acidic, basic, neutral, and oxidative conditions as per ICH guideline Q1A (R2). One of the major degradants was isolated by preparative HPLC and identified characterization by LCMS/MS and HRMS. The newly developed UPLC method was found to be specific with respect to degradation products, and the method has been validated according to the ICH guidelines.