| 摘要 |
PROBLEM TO BE SOLVED: To provide a composition for the controlled delivery of an active substance into an aqueous medium. SOLUTION: The composition is composed of a matrix composed of an active substance and erodible with an aqueous medium in which the composition is to be used and a coating composed of the 1st cellulose derivative having thermoplastic property and essentially insoluble in the aqueous medium in which the composition is to be used and at least one substance selected from a water-soluble or dispersible 2nd cellulose derivative, a plasticizer and a filler. At least one active substance is delivered into the aqueous medium under control by the erosion of at least one surface of the composition at a predetermined erosion rate. The 1st cellulose derivative is ethyl cellulose, etc., and the 2nd cellulose derivative is methyl cellulose, etc. COPYRIGHT: (C)2006,JPO&NCIPI
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