A dispensing device is disclosed for delivering a beneficial agent. The device comprises (1) a housing defining an internal space, (2) an expandable composition comprising a dense member in the space, (3) a composition comprising a beneficial agent and a non-toxic heat responsive carrier in the space,...http://www.google.es/patents/US4871544?utm_source=gb-gplus-sharePatente US4871544 - Ruminant dispensing device
