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: Parameters of renal hemodynamics and tubular sodium and water handling were assessed by clearance techniques in 26 well compensated cirrhotic patients before and after an oral combination of 50 mg of indomethacin and various doses of misoprostol .
### Output Text:
Parameters of renal hemodynamics and tubular <span class="chemical">sodium</span> and water handling were assessed by clearance techniques in 26 well compensated cirrhotic patients before and after an oral combination of 50 mg of <span class="chemical">indomethacin</span> and various doses of <span class="chemical">misoprostol</span> . 