PROBLEM TO BE SOLVED: To provide a polymer suitable for controlling the release of a bioactive agent from an indwelling medical device.SOLUTION: The medical device includes a base material and chlorhexidine or a pharmaceutically acceptable salt thereof disposed in the base material sufficient to reduce microbial growth. The base material includes the polymer including a silicone monomer and a urethane monomer.COPYRIGHT: (C)2012,JPO&INPIT【課題】留置医療機器からの生物活性剤の放出制御に適するポリマーを提供する。【解決手段】医療機器は、基材と、該基材内に微生物増殖を減じるように十分に含ませたクロルヘキシジンまたはその製薬上許容し得る塩とを含む。上記基材は、シリコーンモノマーとウレタンモノマーを含むポリマーを含む。【選択図】なし