A controlled release preparation of an active material comprising a reaction product obtained by reacting (a) a copolymer consisting essentially of maleic anhydride and at least one polyalkylene glycol ether represented by (I):
wherein B represents a residue of a compound having from 2 to 8 hydroxyl groups; R¹ represents an alkenyl group having from 2 to 5 carbon atoms; AO represents an oxyalkylene group having from 2 to 18 carbon atoms or a combination thereof which may be linked together in blocks or at random; R² represents a hydrocarbon group having from 1 to 24 carbon atoms; a represents a positive integer, b and c each represents 0 or a positive integer, and a + b + c = 2 to 8; ℓ ≧ 0, m ≧ 0, n ≧ 0, and ℓ + m + n = 1 to 1000; and (b) an active material. The preparation is soluble both in water and in an organic solvent and exhibits activity for a prolonged period of time.
一种活性物质的控释制剂,该活性物质由以下反应产物组成 (a) 主要由
马来酸酐和至少一种聚亚烷基二醇醚组成的共聚物,该共聚物由(I)代表:
其中 B 代表具有 2 至 8 个羟基的化合物残基;R¹ 代表具有 2 至 5 个碳原子的烯基;AO 代表具有 2 至 18 个碳原子的氧亚烷基或它们的组合,它们可以成块地或随意地连接在一起;R² 代表具有 1 至 24 个碳原子的烃基;a 代表正整数,b 和 c 各代表 0 或正整数,且 a + b + c = 2 至 8;ℓ ≧ 0,m ≧ 0,n ≧ 0,且 ℓ + m + n = 1 至 1000;以及 (b) 活性材料。该制剂既可溶于
水,也可溶于有机溶剂,并可长期保持活性。