To evaluate the efficacy , tolerability , and safety of once-daily @ mg and @ mg SPN-@ ( Oxtellar XR , Supernus Pharmaceuticals ) , an extended-release tablet formulation of oxcarbazepine ( OXC ) , added to @-@ concomitant antiepileptic drugs ( AEDs ) in adults with refractory partial-onset seizures , with or without secondary generalization .