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: Oral treatment with Memantine ( 10mg / kg ) and Ibuprofen ( 50 mg / kg ) daily for 13 days attenuated STZ induced glial activation , apoptotic cell death and post synaptic neurotoxicity in rat brain .
### Output Text:
Oral treatment with <span class="chemical">Memantine</span> ( 10mg / kg ) and <span class="chemical">Ibuprofen</span> ( 50 mg / kg ) daily for 13 days attenuated <span class="chemical">STZ</span> induced glial activation , apoptotic cell death and post synaptic neurotoxicity in rat brain . 