Controversial Points in the Assessment of the Quality of Generic Esomeprazole Formulations

Abstract

A comparative dissolution kinetics test was performed to model the actions of pathological duodenogastric reflux and therapeutic acid suppression on the stability of esomeprazole formulations from three different manufacturers. After exposure to solutions pH (1.2 ±0.05) or (4.0 ±0.05), formulations were transferred to medium pH (7.0 ±0.05), from which aliquots were collected at 0, 4, 10, 15, 20, 30, 45, and 60 min for estimation of esomeprazole concentrations. The duration of exposure of the medicinal formulation of esomeprazole to pathological duodenogastric refluxate was 4 min. In these test conditions, Generic-1 and Generic-2 were found not to be equivalent to the reference drug (RD); the medicinal formulation of the RD was probably influenced by pathological duodenogastric reflux in the stomach, while Generic-2 was completely degraded in moderately acidic medium pH 4.0, which is evidence of the possible adverse influence of its main antisecretory pharmacodynamic effect of the intragastric stability of the medicinal formulation and the active substance.