Pharmaceutical compositions of dimethyl fumarate

A dosage form for treating multiple sclerosis, comprising:

• (a) a therapeutically effective amount of dimethyl fumarate in solid form;
• (b) one or more compounds of Formula (II):
• isomers thereof and salts of any of the foregoing, wherein:
• each of R5 and R7 is independently chosen from hydrogen and methyl;
• Y is chosen from O, S, NH and NR8;
• R6 is chosen from hydrogen, lower alkyl and aryl;
• R8 is chosen from lower alkyl;
• and
• wherein the one or more compounds of Formula (II) are present in a combined total amount of 0.001% to 3% by weight based on total weight of dimethyl fumarate;
• and
• (c) a pharmaceutically acceptable vehicle.