15323
We previously demonstrated that P - glycoprotein ( P - gp ) modulation at the blood - brain barrier ( BBB ) contributes highly to BUP - related respiratory toxicity , by limiting NBUP entrance into the brain .
 Chemical: BUP; Chemical: NBUP
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: BUP; Chemical: NBUP