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: The purpose of this randomized , double - blind , prospective study was to investigate whether intravenous ( i . v . ) administration of methylprednisolone ( MP ) prevents this complication .
### Output Text:
The purpose of this randomized , double - blind , prospective study was to investigate whether intravenous ( i . v . ) administration of <span class="chemical">methylprednisolone</span> ( <span class="chemical">MP</span> ) prevents this complication . 