Isolation and Characterization of a Novel Photo-Degradant of Brexpiprazole Due to an Intramolecular [2 + 2] Cycloaddition Via High Resolution MSn (n = 1 To 3) Analysis and Multi-Dimensional NMR Measurement - Jinsheng Lin; Qilin Wu; Xueyang Liu; Renjian Cao; Qiyun Yong; Dan Li; Wenbin Chen; Min Li; Weiyang Shen (Journal of Pharmaceutical Innovation, 2025)