Study of forced degradation behavior of pramlintide acetate by HPLC and LC-MS.

Pramlintide acetate (Symlin®), a synthetic analogue of the human hormone amylin. It was approved in March 2005 as a subcutaneous injection for the adjunctive treatment of patients who have type 1 or 2 diabetes mellitus. The objective of current investigation was to study the degradation behavior of pramlintide acetate under different ICH recommended stress conditions by HPLC and LC-MS. Pramlintide acetate was subjected to stress conditions of hydrolysis (acidic or alkaline), oxidation, photolysis and thermal decomposition. Extensive degradation products were observed under the hydrolysis, oxidation or thermal stress conditions, while minimal degradation was found in the photolytic conditions. Successful separation of drug from the degradation products was achieved by the validated chromatography (RP-HPLC and SCX-HPLC) methods. Subsequent to isolation, the molecular weight of each component was determined by LC-MS. The LC-MS m/z values and fragmentation patterns of 4 impurities matched with the predicted degradation products of pramlintide acetate.