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: Systemically administered corticosteroids were used in 75 of 210 cases ; a significant number of posterior subcapsular cataracts was found .
### Output Text:
Systemically administered <span class="chemical">corticosteroids</span> were used in 75 of 210 cases ; a significant number of posterior subcapsular cataracts was found . 