Section 3d of the Indian Patents Act 1970: Scope, Interpretation and Recent Developments

Section 3(d) of the Indian Patents Act, 1970 stands as one of the most consequential and globally watched provisions in modern intellectual property law. Introduced in its present form through the Patents (Amendment) Act, 2005, it excludes from patentability the mere discovery of a new form of a known substance unless a meaningful enhancement in efficacy is demonstrated - a deliberate legislative barrier against the pharmaceutical practice commonly known as 'evergreening.' This paper traces the historical origins of the provision, examines its statutory scope and key interpretive concepts, analyses the landmark ruling in Novartis AG v. Union of India (2013), and surveys the most significant judicial developments between 2022 and 2024 that have expanded, procedurally refined, and technologically extended its application. The paper further situates Section 3(d) within the broader TRIPS compliance debate and assesses its real-world consequences for public health, pharmaceutical innovation, and the Indian patent system at large.