In 2005 India amended the Patents Act to introduce protection for product inventions, including patents for pharmaceuticals. Section 3(d) of the Patents Act was qualified with the phrase ‘enhanced efficacy’ for new forms of known substances as a test for being considered an invention. However, the absence of a definition for the term ‘efficacy’ raised many challenges. The exact meaning and elucidation of the phrase ‘enhancement of known efficacy’ was open to interpretation, and was eventually addressed by the Supreme Court.
