11884
Investigation of a limited number of prodrug esters led to the discovery of the ethyl ester prodrug 42 , which demonstrated good intestinal fluid stability and good permeability .
 Chemical: ethyl ester
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ethyl ester