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: Any other suspected cases of ocular toxicity associated with topically applied chloramphenicol should be reported to the National Registry of Drug - Induced Ocular Side Effects , Oregon Health Sciences University , Portland , OR 97201 .
### Output Text:
Any other suspected cases of ocular toxicity associated with topically applied <span class="chemical">chloramphenicol</span> should be reported to the National Registry of Drug - Induced Ocular Side Effects , Oregon Health Sciences University , Portland , OR 97201 . 