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: Calcitonin injection resulted in a potentiation of haloperidol - induced catalepsy and a partial prevention of apomorphine - induced hyperactivity .
### Output Text:
Calcitonin injection resulted in a potentiation of <span class="chemical">haloperidol</span> - induced catalepsy and a partial prevention of <span class="chemical">apomorphine</span> - induced hyperactivity . 