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: OBJECTIVES / HYPOTHESIS : Botulinum toxin ( Botox ) injections into the thyroarytenoid muscles are the current standard of care for adductor spasmodic dysphonia ( ADSD ) .
### Output Text:
OBJECTIVES / HYPOTHESIS : Botulinum toxin ( <span class="chemical">Botox</span> ) injections into the thyroarytenoid muscles are the current standard of care for adductor spasmodic dysphonia ( ADSD ) . 