A chromatographic determination of the stability of solutions of amlodipine benazepril and amlodipine besilate

Abstract

Drug substances (or actives) and drug products can be susceptible to chemicaldegradation by different mechanisms such as hydrolysis, and oxidation, leading to loss of potency and formation of degradation products. Several factors, such as temperature, storage containers, excipients and oxygen affect the stability of actives and drug products. Stability testing is carried out to investigate how different factors affect the quality of an active or a drug product with time and to determine a time interval over which the potency of the drug remains within a certain limit. Stability of an active relates to its ability to remain within a certain acceptance criteria so as to ensure its strength, purity, quality and identity during a defined period of time. The two products investigated during this study were amlodipine besilate tablets and amlodipine benazepril capsules. Amlodipine is the active present in amlodipine besilate whereas in amlodipine benazepril two actives are present which are amlodipine and benazepril hydrochloride.The objectives of this project were to investigate the stability of sample solutions and standard solutions of both products stored under different conditions so as to determine whether degradation occurred over time, as measured by the loss in percentage assay of the active, to determine whether different storage conditions affected the degree of degradation of these products, and to determine whether there was a time interval between the preparation of solutions and their analysis during which they were still stable, where stability of the active was related to its ability to remain within the limits defined in the acceptance criteria.