Indian pharmaceutical patent prosecution: The changing role of Section 3(d)

PLoS One. 2018 Apr 2;13(4):e0194714. doi: 10.1371/journal.pone.0194714. eCollection 2018.


India, like many developing countries, only recently began to grant pharmaceutical product patents. Indian patent law includes a provision, Section 3(d), which tries to limit grant of "secondary" pharmaceutical patents, i.e. patents on new forms of existing molecules and drugs. Previous research suggests the provision was rarely used against secondary applications in the years immediately following its enactment, and where it was, was redundant to other aspects of the patent law, raising concerns that 3(d) was being under-utilized by the Indian Patent Office. This paper uses a novel data source, the patent office's first examination reports, to examine changes in the use of the provision. We find a sharp increase over time in the use of Section 3(d), including on the main claims of patent applications, though it continues to be used in conjunction with other types of objections to patentability. More surprisingly, see a sharp increase in the use of the provision against primary patent applications, contrary to its intent, raising concerns about potential over-utilization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Drug Industry / legislation & jurisprudence*
  • Humans
  • India
  • Patents as Topic / legislation & jurisprudence*
  • Patents as Topic / statistics & numerical data*

Grants and funding

The research was funded by the Economic and Social Research Council, Grant ES/K010999/1 ( (KCS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.