16656
Concentrations of IR3535 ( (R) ) - free acid were several thousand - fold higher than the parent compound and peaked at the first two sampling points ( 4h and 8h after dermal application ) .
 Chemical: IR3535
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: IR3535 
Answer:
 Chemical: IR3535