Lansoprazole Sulfide-D4 is a deuterium labeled Lansoprazole Sulfide. Lansoprazole Sulfide (T21128) is an orally active anti-TB (Mycobacterium tuberculosis)agent with IC50 values of 0.59 μM intracellularly and 0.46 μM in broth.Lansoprazole Sulfide is an active metabolite of the proton pump inhibitor Lansoprazole.