They matter a great deal to generic companies active in the us generic markets because they represent another tool used by branded companies to prolong their period of market control as patent expiry approaches 授权的非专利药对于活跃在美国非专利药市场上的非专利药生产商非常重要，是因为它代表着品牌药公司在专利行将过期之时，所使用的另一种延长其市场控制期的方式。
