Summary
The Delhi High Court, in Syngenta Participations AG v. Controller of Patents and Designs, set aside the rejection of Syngenta’s patent application for a monohydrate crystalline polymorph of an agrochemical compound on the grounds of lack of inventive step under Section 2(1)(ja) and non-patentability under Section 3(d) of the Patents Act, 1970. The Court found that the Patent Office had incorrectly characterised thermal stability as an “inherent property” of monohydrate polymorphs without scientific evidence. It further clarified that, in the context of agrochemicals, “efficacy” under Section 3(d) is not limited to therapeutic efficacy, but extends to functional and practical advantages such as enhanced stability and improved field performance.
Background
Syngenta Participations AG (“Syngenta”) filed Indian Patent Application No. 201617031900 for a crystalline monohydrate polymorph of an agrochemical fungicidal compound used in suspension concentrate (SC) formulations for agricultural spraying. It claimed that previously known polymorphic forms of the compound were unstable in SC formulations and susceptible to crystal growth during storage and use, leading to thickening, solidification, and blockage of spray nozzles. It asserted that the claimed monohydrate polymorph exhibited superior thermal stability under high temperature and humidity conditions, thereby reducing crystallisation during use.
Following objections in the First Examination Report under Sections 2(1)(ja) and 3(d), Syngenta submitted comparative experimental data and an expert affidavit from Dr. John Hone to demonstrate the technical advantages of the invention. Despite these submissions, the Controller rejected the application, concluding that thermal stability was inherent to monohydrate forms and that no enhanced efficacy had been shown.
Aggrieved by the refusal, Syngenta filed an appeal before the Delhi High Court under Section 117A of the Patents Act.
Arguments by Parties
Syngenta argued that the Controller had wrongly rejected the thermal stability data and had incorrectly assumed, without scientific basis, that enhanced thermal stability was an inherent property of monohydrate polymorphs. It contended that polymorphism is inherently unpredictable, and that different polymorphs of the same compound can exhibit distinct physical and chemical properties.
To substantiate its claims, Syngenta relied on experimental data demonstrating that the claimed polymorph exhibited enhanced stability and prevented undesirable crystal growth in SC formulations. According to Syngenta, the improved stability enhanced spray performance, reduced phytotoxicity risks, and prevented nozzle blockage during agricultural application.
On Section 3(d), Syngenta argued that the concept of “therapeutic efficacy” developed in pharmaceutical patent jurisprudence could not be mechanically extended to agrochemical inventions. It submitted that, for agrochemical products, efficacy must be evaluated in terms of practical utility, functional performance, and operational effectiveness.
The Controller relied on prior art documents disclosing the same fungicidal compound in anhydrous form and argued that the claimed monohydrate polymorph lacked any unexpected technical effect. Citing Novartis AG v. Union of India, the Controller contended that improved thermodynamic stability alone could not satisfy Section 3(d).
Issues before the Court
- Whether thermal stability could be regarded as an inherent property of polymorphs; and
- Whether the claimed agrochemical product satisfied the requirement of enhanced efficacy under Section 3(d) of the Patents Act, 1970.
Observations BY the Court
The Court undertook a detailed analysis of scientific literature on polymorphism and noted that polymorphic behaviour is inherently unpredictable. Referring to scientific articles and earlier judicial decisions, it observed that different polymorphs may exhibit distinct physical properties such as stability, solubility, and hygroscopicity. The Court therefore rejected the Controller’s assumption that thermal stability is an inherent property of monohydrate polymorphs, particularly in the absence of supporting scientific evidence.
The Court also found that the Patent Office had failed to adequately examine the technical data submitted by Syngenta. It observed that the experimental evidence demonstrated that the claimed monohydrate polymorph remained stable in SC formulations and prevented crystallisation at higher temperatures, thereby avoiding blockage of agricultural spray equipment. Since the prior art neither disclosed the monohydrate form nor its enhanced stability characteristics, the Court concluded that the rejection on the ground of lack of inventive step was unsustainable.
With respect to Section 3(d), the Court clarified that the standard of “therapeutic efficacy” articulated in Novartis AG v. Union of India was developed specifically in the context of pharmaceutical inventions. In the case of agrochemicals, efficacy must instead be assessed with reference to the product’s intended function and practical utility.
The Court held that improved thermal stability, which enabled effective spraying without crystallisation or nozzle blockage, constituted enhanced efficacy within the meaning of Section 3(d). In reaching this conclusion, the Court also relied on Novozymes v. Assistant Controller of Patents, where increased thermostability was recognised as enhanced efficacy because it improved the practical utility and performance of the product.
Conclusion
The Delhi High Court held that the Patent Office had failed to properly appreciate the scientific evidence on record and had rejected the application without adequate reasoning. The impugned order was set aside and the matter was remanded to the Patent Office for fresh consideration in light of the Court’s observations concerning the interpretation and application of Section 3(d) in the context of agrochemical inventions.
Citation: Syngenta Participations Ag vs Controller Of Patents Designs, Delhi HC, 4 May, 2026, C.A.(COMM.IPD-PAT) 49/2023. Accessible at https://indiankanoon.org/doc/114024683/
Article Review: Dr. Vasundhara Paliwal