15218
In rats , intestinal secretion is suggested to be involved in the fecal excretion as a minor component because fecal excretion after intravenous administration was observed ( 15 . 66 % ) and biliary excretion was almost negligible .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None