Tylvalosin-d9 (Acetylisovaleryltylo sin-d9) is the deuterium labeled Tylvalosin (HY-128423A)[1]. Tylvalosin is a third-generation macrolide, with anti-inflammatory property. Tylvalosin decreases the levels of IL-8, IL-6, IL-1beta, PGE2, TNF-alpha and NO, and reduces the inflammatory cells recruitment and activation in mouse acute lung injury model[2].