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: PURPOSE : To determine whether Myocet ( liposome - encapsulated doxorubicin ; The Liposome Company , Elan Corporation , Princeton , NJ ) in combination with cyclophosphamide significantly reduces doxorubicin cardiotoxicity while providing comparable antitumor efficacy in first - line treatment of metastatic breast cancer ( MBC ) .
### Output Text:
PURPOSE : To determine whether <span class="chemical">Myocet</span> ( liposome - encapsulated <span class="chemical">doxorubicin</span> ; The Liposome Company , Elan Corporation , Princeton , NJ ) in combination with <span class="chemical">cyclophosphamide</span> significantly reduces <span class="chemical">doxorubicin</span> cardiotoxicity while providing comparable antitumor efficacy in first - line treatment of metastatic breast cancer ( MBC ) . 