Evergreening is a practice adopted by drug MNCs under which they make a modified version of their currently patented invention to extent patentability for further 20 years. Advantage of evergreening is that competitors -especially generic manufactures can’t produce the existing patented product for another five years. In India, the 2005 patent amendment has Section 3 (d) that rejects inventions that are not substantive from patentability to eliminate evergreening.
