Mixed Amphetamine Salts are the generic form of Adderall
and racemic amphetamine). Only the shorter-acting preparation is sold as a generic medication. The molecular make-up is the same, although some generic preparations are a little weaker or stronger than brand-name. The XR delivery system works for ~ 12 hours, "regular" Adderall (dextroamphetamine and racemic amphetamine) or MAS for ~ 6 hours.