follows: 1/4 dextroamphetamine saccharate 1/4 dextroamphetamine sulfate, USP 1/4 (racemic) amphetamine aspartate monohydrate 1/4 (racemic) amphetamine sulfate, USP [ edit ] Metabolism "The mean elimination half-life for d-amphetamine is 10 hours in adults; 11 hours in adolescents aged 13–17 years and weighing less than or equal to 75 kg/165 lbs; and