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: For patients with bilateral abductor paralysis , age , sex , paralytic Botox dose , prior Botox dose , and course following paralysis were noted .
### Output Text:
For patients with bilateral abductor paralysis , age , sex , paralytic <span class="chemical">Botox</span> dose , prior <span class="chemical">Botox</span> dose , and course following paralysis were noted . 