An erodible device is disclosed for delivering an agent to {HEAD ~ an environment} of {TAIL ~ use} 
of
An erodible device is disclosed for delivering an agent to { HEAD ~ an environment } of { TAIL ~ use }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL