22688
Promising new therapeutics , many of which are charged and macromolecular , are not able to passively extravasate , let alone cross cell membranes , and stay mainly in the blood pool upon intravenous injection until clearance .
 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