27519
In addition , we have studied the effect of these drugs upon the ocular hypotensive action of a non - selective beta - adrenergic receptor ( timolol ) and a selective alpha 2 - adrenergic receptor agonist ( brimonidine ) in normotensive rabbits .
 Chemical: timolol; Chemical: brimonidine
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: timolol; Chemical: brimonidine