I guess you can use
fq={!raw f=itemtype}Supply Chain Intermediaries
for that purpose
It tuns out that you have to use !term instead of !raw for Solr version >= 4.0
http://mail-archives.apache.org/mod_mbox/lucene-solr-user/201012.mbox/%3C4D121F73.3090706@jhu.edu%3E
Have a nice day.