High Quality Content by WIKIPEDIA articles! Evergreening refers to a variety of legal and business strategies by which technology producers with patents over products that are about to expire, retain rent from them by either taking out new patents (for example over associated delivery systems, or new pharmaceutical mixtures) or by buying out or frustrating competitors, for longer periods of time than would normally be permissible under the law. Evergreening is not a formal concept of patent law; it is best understood as a social idea used to refer to the myriad ways in which pharmaceutical patent owners use the law and related regulatory processes to extend their high rent-earning intellectual property rights, otherwise known as intellectual monopoly privileges, particularly over highly profitable (either in total sales volume or price per unit) 'blockbuster' drugs. Thus, while the courts are an instrument frequently used by pharmaceutical brand name manufacturers to prolong their...