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: With institutional approval , 35 Sprague - Dawley rats were randomly allocated to receive daily subcutaneous doses of 10 mg / kg prednisolone ( P10 group ) , 100 mg / kg prednisolone ( P100 group ) , or an equal volume of saline ( S group ) for 7 days .
### Output Text:
With institutional approval , 35 Sprague - Dawley rats were randomly allocated to receive daily subcutaneous doses of 10 mg / kg <span class="chemical">prednisolone</span> ( P10 group ) , 100 mg / kg <span class="chemical">prednisolone</span> ( P100 group ) , or an equal volume of saline ( S group ) for 7 days . 