Introduction
In a notable decision concerning patent protection for new forms of known chemical compounds in the agrochemical sector, the Delhi High Court has emphasised the importance of experimental evidence demonstrating technical advantages of a new crystalline form.
The ruling underscores that polymorphism — the ability of a substance to exist in multiple crystal structures — is often unpredictable, and courts must carefully evaluate whether a new form offers genuine improvements over known versions rather than dismissing it as a mere variation.
Factual And Procedural Background
Syngenta Participations AG filed a patent application in India for a specific crystalline monohydrate form of a known fungicide compound used to control plant diseases.
This new form was claimed to provide better stability in certain agricultural formulations compared to the previously known anhydrous version.
The Indian Patent Office, after examination and hearing, refused the application. Syngenta challenged this refusal by filing an appeal before the Delhi High Court.
Arguments Before The Court
The matter was heard by the court, with detailed arguments presented by senior advocates on both sides.
- The company submitted experimental data and expert evidence to show the practical benefits of the new form.
- The controller defended the rejection primarily on grounds of obviousness and lack of sufficient improvement.
Key Issues In The Case
| Issue | Description |
|---|---|
| Patentability of Polymorphs | Whether a new crystalline form of a known compound qualifies for patent protection. |
| Technical Advancement | Whether the claimed monohydrate form demonstrated enhanced stability and practical utility. |
| Obviousness | Whether the new form would have been obvious to a skilled person in the field. |
| Experimental Evidence | Whether the applicant provided sufficient scientific data to establish improved properties. |
Importance Of The Ruling
The decision highlights the significance of scientific and experimental evidence in pharmaceutical and agrochemical patent disputes involving polymorphic forms.
The court recognised that polymorphism is inherently unpredictable and that each crystalline structure may possess distinct physical and technical properties.
Accordingly, courts and patent authorities must assess whether the claimed form provides real technical advantages over previously known compounds instead of treating it as a routine variation.
Significance For The Agrochemical Sector
- Strengthens protection for innovative crystalline forms of known compounds.
- Encourages research into improved agrochemical formulations.
- Highlights the role of expert evidence in patent litigation.
- Clarifies standards for assessing inventive step and technical effect.
Dispute Over Patentability of New Polymorph
The central dispute was whether the new monohydrate crystalline form of the known compound involved an inventive step and whether it qualified for patent protection or fell under the exclusion for new forms of known substances that do not demonstrate enhanced efficacy.
The Patent Office took the view that improved thermal stability was an inherent and expected property of such forms and that the applicant had not shown meaningful enhancement in performance.
Syngenta argued that preparing a stable and useful new polymorph requires significant research, that the behaviour of different crystal forms is unpredictable, and that their data proved real advantages in formulation stability and reduced issues during agricultural application.
Reasoning And Analysis Of The Judge
The Court highlighted that polymorphism is a complex phenomenon where different crystal arrangements of the same molecule can lead to significantly different physical behaviours, even though the chemical composition remains identical.
He referred to scientific literature explaining that it is generally not possible to predict in advance whether a new polymorph will form or what its properties will be.
Court Approach To Inventive Step
The court discussed the judgement in F-Hoffmann-La Roche Ltd & Anr vs Cipla Ltd, 2015:DHC:9674-DB, where the Division Bench of the Delhi High Court laid down a structured approach for assessing inventive step, including the following:
- Identifying the person skilled in the art
- Determining the inventive concept
- Assessing common general knowledge
- Examining differences from prior art
- Evaluating whether those differences would have been obvious
Justice Gedela also relied upon Agriboard International LLC vs Deputy Controller of Patents & Designs, 2022 SCC OnLine Del 940, stressing that a controller must properly analyse the prior art, the new invention, and how it would appear to a skilled person rather than reaching a bare conclusion of obviousness.
Section 3(d) Patents Act Analysis
On the objection under Section 3(d) of the Patents Act, the court referred to the Supreme Court’s landmark decision in Novartis AG vs Union of India & Others, (2013) 6 SCC 1.
While noting that the stricter “therapeutic efficacy” test applies mainly to pharmaceuticals, the judge observed that in the agrochemical field, improvements in formulation stability, handling, and reduced plant toxicity can constitute enhanced efficacy for the purpose of patentability.
Findings On Experimental Evidence
The court found that the Controller had not adequately explained why the experimental evidence of superior stability in practical agricultural suspensions was insufficient.
It also criticised the reliance on “common general knowledge” without citing specific sources.
The judge concluded that the applicant had demonstrated a technical advance through concrete data showing that the new form solved real problems of crystal growth and equipment blockages that occurred with the known form.
Key Legal Principles Highlighted
| Legal Issue | Court Observation |
|---|---|
| Inventive Step | Must be assessed from the perspective of a skilled person using prior art analysis. |
| Polymorphism | Different crystal forms may display unpredictable physical properties. |
| Section 3(d) | Enhanced efficacy in agrochemicals may include stability and handling improvements. |
| Experimental Evidence | Technical data demonstrating practical advantages must be properly evaluated. |
| Common General Knowledge | Cannot be relied upon without proper supporting references. |
Important Takeaways
- Polymorph inventions can qualify for patent protection if they demonstrate technical advancement.
- Inventive step analysis must follow a structured legal framework.
- Section 3(d) standards may differ between pharmaceutical and agrochemical inventions.
- Courts expect patent authorities to provide reasoned analysis backed by evidence.
- Practical improvements such as formulation stability and reduced operational issues can support patentability.
Final Decision of the Court
The Delhi High Court allowed Syngenta’s appeal. The order of the controller refusing the patent application was set aside. The matter was remanded back to the Patent Office for fresh consideration in accordance with the observations made by the court.
Point of Law Settled in the Case
This judgement reinforces that in cases involving new polymorphic forms, patent examiners and courts must give due weight to experimental evidence of improved properties and practical advantages, particularly in agrochemicals.
It clarifies the unpredictability of polymorphism and demonstrates technical benefits in formulation stability that can support both the inventive step and enhanced efficacy under Section 3(d).
Mere assertions that a new form is obvious or inherently stable are not enough; the analysis must be evidence-based and reasoned.
Key Legal Principles from the Judgement
- Experimental evidence must be properly evaluated in patent disputes involving polymorphic forms.
- Improved formulation stability can support inventive step and enhanced efficacy.
- Polymorphism in agrochemical inventions is scientifically unpredictable.
- Patent objections under Section 3(d) must be supported by evidence-based reasoning.
- Mere assumptions regarding obviousness or inherent stability are insufficient.
Case Details
| Particulars | Details |
|---|---|
| Case Title | Syngenta Participations AG versus Controller of Patents Designs |
| Date of Order | 04.05.2026 |
| Case Number | C.A. (COMM.IPD-PAT) 49/2023 |
| Neutral Citation | 2026:DHC:3766 |
| Name of Court | High Court of Delhi |
| Name of the Honourable Judge | Hon’ble Mr Justice Tushar Rao Gedela |
Disclaimer: Readers are advised not to treat this as a substitute for legal advice, as it may contain errors in perception, interpretation, and presentation.
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
