Methods for determination of bisoprolol and related substances mostly use UV
detection and phosphate buffer and are not suitable for MS detection. In
this study, LC-UV-MS/MS for separation and characterization of bisoprolol
related substances was developed, validated, and applied for studying the
degradation products of bisoprolol when exposed to hydrolytic stress, heat
and light. The method uses C18 column, formic acid in water and acetonitrile
as mobile phases, gradient elution, UV, and MS detection. Forced degradation
revealed that acid hydrolysis produces the most intensive transformation of
bisoprolol to its impurity A, along with impurities L and D. Alkaline
hydrolysis produced impurities A, L, Q, G, and K; oxidative and thermal
degradation produced impurities A, L, and K, and photodegradation produced
impurities A, L, G and, K, all characterized by their mass spectral data.
The developed method using two detection systems was demonstrated as
efficient since mass spectra allowed identification of the related
substances of bisoprolol and quantification was possible using absorbance
measurement at 270 nm. The obtained results will fill in the lack of data on
the fragmentation patterns of bisoprolol and related substances that can be
used by researchers and practitioners in research and quality control
laboratories.