A white powder for reconstitution. MiraLax (polyethylene glycol 3350, NF) is a synthetic polyglycol having an average molecular weight of 3350. The actual molecular weight is not less than 90.0 percent and not greater than 110.0 percent of the nominal value. The chemical formula is HO(C2H4O)n H in which n represents the average number of oxyethylene groups. Below 55 C it is a free flowing white powder freely soluble in water.

Mircera, methoxy polyethylene glycol-epoetin beta, is an ESA which differs from erythropoietin through formation of a chemical bond between either the N-terminal amino group or the e-amino group of any lysine present in erythropoietin, predominantly Lys52 and Lys45 and methoxy polyethylene glycol (PEG) butanoic acid (approximately 30,000 daltons). This results in a total molecular weight of approximately 60,000 daltons. Mircera (methoxy polyethylene glycol-epoetin beta) is formulated as a sterile, preservative-free protein solution for IV or SC administration.