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: Despite administration of phenytoin and lorazepam , the seizures persisted and occurred only during amphotercin B administration .
### Output Text:
Despite administration of <span class="chemical">phenytoin</span> and <span class="chemical">lorazepam</span> , the seizures persisted and occurred only during <span class="chemical">amphotercin B</span> administration . 