PANHEMATIN (hemin for injection) is an enzyme inhibitor derived from processed red blood cells. Hemin for injection was known previously as hematin. The term hematin has been used to describe the chemical reaction product of hemin and sodium carbonate solution. Hemin is an iron containing metalloporphyrin. Chemically hemin is represented as chloro [7,12-diethenyl-3,8,13,17-tetramethyl-21H,23H-porphine-2,18-dipropanoato (2-)-N21,N22,N23,N24] iron. The structural formula for hemin is: