In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Eslicarbazepine acetate ( BIA 2 - 093 , S - ( - ) - 10 - acetoxy - 10 , 11 - dihydro - 5H - dibenzo / b , f / azepine - 5 - carboxamide ) is a novel antiepileptic drug , now in Phase III clinical trials , designed with the aim of improving efficacy and safety in comparison with the structurally related drugs carbamazepine ( CBZ ) and oxcarbazepine ( OXC ) .
### Output Text:
<span class="chemical">Eslicarbazepine acetate</span> ( <span class="chemical">BIA 2 - 093</span> , <span class="chemical">S - ( - ) - 10 - acetoxy - 10 , 11 - dihydro - 5H - dibenzo / b , f / azepine - 5 - carboxamide</span> ) is a novel antiepileptic drug , now in Phase III clinical trials , designed with the aim of improving efficacy and safety in comparison with the structurally related drugs <span class="chemical">carbamazepine</span> ( <span class="chemical">CBZ</span> ) and <span class="chemical">oxcarbazepine</span> ( <span class="chemical">OXC</span> ) . 