L-aminocarnityl-succinyl-leucyl-argininal-diethylacetal (Myodur or C101) is a compound that comprise a carrier residue that is an analog of carnitine, a linker group, and a residue of a protease inhibitor comprising an acetal derivative of the aldehyde group. Myodur is a muscle cell targeted product that inhibits calpain in an effort to preserve muscle tissue. In 2006 CepTor Corporation (OTCBB:CEPO), a development-stage biopharmaceutical company focusing on cell-targeted therapeutic products for neuromuscular and neurodegenerative diseases announced that the Office of Orphan Products Development of the Food and Drug Administration (FDA) granted orphan drug designation for Myodur for both Duchenne and Becker muscular dystrophies. Myodur development has been discontinued.