Identification and characterization of rotigotine degradation products

Rotigotine is an approved drug for treatment of Parkinson's disease, marketed as a transdermal patch, which shows sensitivity to oxidation 1–3. Identification and characterization of drug related impurities are important for the development of methods indicative of stability. Thus, forced degradation studies were performed using alkaline, acidic, metal ions, oxidative and photolytic conditions. In addition, accelerated stability study of tablets containing degrading agents and kept in stability chamber for 24 months was performed. Samples were evaluated by HPLC coupled to UV, CAD and MASS detector, using an Orbitrap mass analyzer. Rotigotine was stable under alkaline, acidic and metallic conditions. However, it was observed the formation of degradation products in oxidative condition generating two major products, besides other impurities. The structure of the degradation products was elucidated by LC-MS/MS from their fragments. Thus, an indicative method of stability for rotigotine and its impurities will be developed and validated.