A delivery system is disclosed for delivering a beneficial agent to an animal. The delivery system comprises a wall that surrounds a lumen, said wall comprising a composition that limits the passage of fluid into the system and a composition that permits the passage of fluid into the system. The lumen...http://www.google.com.au/patents/US5057318?utm_source=gb-gplus-sharePatent US5057318 - Delivery system for beneficial agent over a broad range of rates
