Background: Drug stability is essential in the process of drug production, storage, appliance,
and so on. Some drugs’ degradation products may even have a toxic side effect, which can result in
safety risks and economic losses. Therefore, it is very imperative to develop a suitable stability indicating
an analytical method for anastrozole which could be used for stability testing, routine and in-process
quality control analysis or other further studies.
Methods: A reverse-phase high-performance liquid chromatography method was developed and validated
for the degradation kinetics study of anastrozole, a selective non-steroid third-generation aromatase
inhibitor, which would provide a basis for further studies on anastrozole. The degradation product
was confirmed by ultra-performance liquid chromatography with tandem mass spectrometry.
Results: Results showed that the degradation behavior of anastrozole followed first-order kinetics in
different temperatures, pH values and oxidation conditions. It was suggested that the degradation behavior
of anastrozole was pH-dependent and it’s more stable at lower pH values.
Conclusion: A high performance liquid chromatography method was established and used to determine
the residual concentration of anastrozole in this study. It was found that the degradation behavior of
anastrozole followed first-order kinetics at different temperatures, pH values and oxidation conditions.
According to the results, the degradation of anastrozole was found to be pH-dependent and it is more
unstable in alkaline conditions. The information of degradation kinetics will be useful for understanding
the chemical stability of anastrozole and provide a reference for the further preparation research and
clinical therapy of anastrozole.