Optimization of a forced degradation study of atorvastatin employing an experimental design approach

Abstract

This study involved the optimization of experimental conditions for the forced degradation of atorvastatin employing the experimental design (DoE) approach, as a scientific multifactorial strategy. Using 2n full factorial design, stress conditions of oxidative, hydrolytic and thermal degradation were optimized to obtain a targeted level of atorvastatin degradation. Atorvastatin and all related and degradation products were separated on Poroshell 120 EC C18 50 ´ 3.0 mm 2.7 μm, using 10 mM ammonium formate and acetonitrile as mobile phases in the gradient mode. The impurity structures were confirmed by the direct hyphenation of a liquid chromatograph to an ion trap mass spectrometer with a heated electrospray ionization interface. This study highlights the multifold benefits of implementing the DoE concept, which provides a better understanding of the significant factors responsible for degradation and ensures a successful way to achieve degradation, thereby replacing the trial and error approach used in conventional forced degradation studies.

Keywords

• atorvastatin, related and degradation products, lc/ms, experimental design, forced degradation