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: CONCLUSION : This modified liposomal doxorubicin regimen results in less toxicity ( stomatitis , hand - foot syndrome ) than the standard FDA - approved dose schedule .
### Output Text:
CONCLUSION : This modified liposomal <span class="chemical">doxorubicin</span> regimen results in less toxicity ( stomatitis , hand - foot syndrome ) than the standard FDA - approved dose schedule . 