POLYMERS WITH CONTROLLED PHYSICAL STATE AND BIOERODIBILITY

摘要

The present invention relates to polymers useful as orthopedic implants or vehicles for the sustained delivery of pharmaceutical, cosmetic and agricultural agents. The polymers are prepared in such a manner that the rate and degree to which they are hydrolyzed can be controlled without addition of exogeneous acid. This discovery resides in th e incorporation of esters of short-chain .alpha.-hydroxy acids such as esters of glycolic acid, lactic acid or glycolic-co-lactic acid copolymer into the polymer chain and variation of the amount of these esters relative to the polymer as a whole.