3877
Permeability coefficients for up to 28 drugs were determined using one or several of four intestinal regions : duodenum , jejunum , ileum and colon and 10 drugs were studied bidirectionally .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None