Pantoprazole-d8 (BY1023-d8) sodium is a deuterium-labeled version of Pantoprazole. Pantoprazole (BY1023) is an orally active, potent proton pump inhibitor (PPI). As a substituted benzimidazole, Pantoprazole effectively inhibits H+/K+-ATPase with an IC50 of 6.8 µM. It enhances pH stability and possesses antisecretory and anti-ulcer properties. When combined with Doxorubicin, Pantoprazole significantly extends tumor growth delay.