Ethylene oxide-propylene oxide copolymer, MW 3500-4125 Ethylene oxide/propylene oxide copolymer (avg MW 3,500-4,125) Poloxamer-331 alpha-Hydro-omega-hydroxypoly(oxyethylene)/poly(oxypropylene)(53-59 moles)/poly(oxyethylene)(14-16 moles) block copolymer,