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: Daily dosages of 5 - 10 mg corrected the hyperprolactinemia and restored menstruation in four of the six patients .
### Output Text:
Daily dosages of 5 - 10 mg corrected the hyperprolactinemia and restored menstruation in four of the six patients . 