| 摘要 |
An active agent is liberated into an aq. environment or medium at a constant pH of 6-9 using a dispersion of the agent in a body of a CO2H-contg. polymer (I) (or polymer compsn.) contg. 1 ionisable H atom per 8-22C, such that when the body is placed in the environment, it is eroded at controlled rate over a prolonged period due to ionisation of the CO2H gp., thus releasing the agent. Active agents may be e.g. pesticides, catalysts, preservatives, plant growth control agents etc. or esp. medicaments for use in mammal bodies. (I) can be shaped into occular implants, suppositories, intrauterine devices etc. and their rate of dissolution can be controlled by ionisable H to C atom ratio. |
