6612
The cumulative release of DOX - loaded composite microsphere in vitro showed that the drug release rate was much faster below its pKa than that of above its pKa .
 Chemical: DOX
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: DOX