4571
The particle loaded gels can release timolol in phosphate buffered saline ( PBS ) for about a month at room temperature .
 Chemical: timolol; Chemical: phosphate
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: timolol, phosphate 
Answer:
 Chemical: timolol; Chemical: phosphate