Thermodynamic stability in agrochemicals constitutes enhanced efficacy under Section 3(d) of the Patents Act.

The Appellant filed a patent application for a crystalline monohydrate polymorph of a known compound (Formula I) used for controlling plant pathogenic fungi

The Respondent (Controller) refused the application via an order dated 21.07.2023 on grounds of lack of inventive step under Section 2(1)(ja) and non-patentability under Section 3(d) of the Patents Act, 1970

The Controller held that thermal stability is an "inherent property" of monohydrates and found no surprising technical effect or enhanced efficacy over the known anhydrous forms disclosed in prior arts D1-D4

The Appellant challenged this, citing experimental data on thermodynamic stability and its role in lowering phytotoxicity in suspension concentrate (SC) formulations

1. Whether the claimed monohydrate crystalline polymorph involves an inventive step under Section 2(1)(ja) given the unpredictable nature of polymorphism

2. Whether thermodynamic stability in agrochemicals constitutes "enhancement of known efficacy" under Section 3(d) to overcome the bar of non-patentability

The court applied Section 2(1)(ja) regarding "inventive step," requiring a technical advance or economic significance that is non-obvious to a person skilled in the art

Analysis of obviousness followed the five-step inquiry established in F-Hoffmann-la Roche Ltd. v. Cipla Ltd. and the three-pronged test from Agriboard International LLC v. Deputy Controller, emphasizing that "common general knowledge" must be substantiated by sources

For Section 3(d), the court interpreted "efficacy" based on Novartis AG v. Union of India, noting that while "therapeutic efficacy" applies to medicines, efficacy for other products depends on their specific function, utility, or purpose

It further relied on Novozymes v. Assistant Controller to affirm that thermostability can constitute enhanced efficacy in non-pharmaceutical contexts

The court found the Controller's rejection under Section 2(1)(ja) flawed because it dismissed thermal stability as an "inherent property" without citing any scientific source, contradicting established literature that polymorphism is unpredictable

The Appellant provided experimental data (Example 3, Table 3) showing the monohydrate remained stable at 60°C, preventing crystal growth that clogs agricultural sprayers—a technical advance over the anhydrous prior arts D1-D4 which the Controller failed to adequately analyze

Regarding Section 3(d), the court distinguished the Novartis "therapeutic efficacy" standard (limited to medicines) from the current agrochemical application

It reasoned that since Indian agricultural regions experience high temperatures (35°C–50°C), a polymorph that remains stable and prevents equipment clogging directly enhances the "utility and purpose" of the fungicide

Thus, thermodynamic stability in this context qualifies as an "enhancement of efficacy"

The court set aside the impugned order dated 21.07.2023. The case was remanded to the Patent Office for fresh consideration on merits under Section 2(1)(ja), to be decided within six months