HAUPPAUGE, N.Y.--(BUSINESS WIRE)--United-Guardian, Inc. (AMEX:UG) announced today its stock has been added to the Russell Microcap Index, which measures the performance of the microcap segment of the U.S. equity market. The addition was made after the Russell Investment Group reconstituted its comprehensive set of U.S. and global equity indexes on June 27, 2008.