| 摘要 |
Delivery systems and devices for the controlled release of chemicals, including drugs, comprise a wall, formed in part at least, of a porous material, including a porous fabric material, pores of which contain a hydrogel, said porous wall being in contact with at least a portion of a reservoir comprised of a chemical and, if desired, a water-soluble liquid excipient and/or a detergent. Emphasis is given to said systems and devices in which the hydrogel is gelled cellulose triacetate, and to their use for controlled release of drugs to animals, especially to ruminants over prolonged periods of time. |
