4521
Rheological measurements of gel vehicle formulations indicated that the in situ gel forming system with optimum sol - gel transition temperature of 28 . 7 degrees C could be formed using a combination of P407 and PVA at ratio of 15 - 10 % ( w / v ) .
 Chemical: P407; Chemical: PVA
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: P407; Chemical: PVA