Photodegradation kinetics of lisdexamfetamine dimesylate and structure elucidation of its degradation products by LC-ESI-QTOF

Herein, we investigate the photodegradation of lisdexamfetamine (LDX) in an aqueous solution. The experiment is carried out by exposing the drug in solution to UV radiation for different periods of time during 48 h. The fragmentation pattern of LDX is established, and its two degradation products are identified (DP-01 and DP-02) and structurally characterized via liquid chromatography coupled with hybrid quadrupole time-of-flight electrospray ionization (LC-ESI-QTOF) mass spectrometry. Furthermore, the photodegradation kinetics of LDX is determined via LC-ESI-QTOF (r = 0.9905; k = 0.0204 h−1; and t1/2 = 33.91 h) and RP-LC-CAD (r = 0.9960; k = 0.0234 h−1; and t1/2 = 29.67 h). LDX is found to be unstable in the presence of light under the evaluated conditions.