The Hon’ble Delhi High Court, in its decision dated May 7, 2025, in the case of Crystal Crop Protection Limited vs Safex Chemicals India Limited & Ors [CS(COMM) 196/2024, 2025: DHC:3382], dismissed the application of Crystal Crop for the grant of interim injunction as the Court found that the dyeing agent or pigment is an essential element of the suit patent and the defendant product does not contain the ‘dyeing agent or pigment’. Hence, the Court noted that the present case is not a case of ‘literal infringement; rather, the infringement analysis ought to be based on the ‘Doctrine of Equivalents’. The Court was of the prima facie view that in the present case, the contentions raised by the defendants raise material questions that warrant a full trial.
Factual Matrix
In the instant patent infringement suit, an application was filed by the plaintiff seeking the relief of an interim injunction restraining the defendant from infringing the plaintiff’s patent number IN 417213, entitled “Weedicidal Formulation and Method of Manufacture thereof”. The instant suit patent disclosed an herbicidal composition comprising ‘Clodinafop 9% and Metribuzin 20%’ (a ratio 1:2.2) with a surfactant, dyeing agent, pigment, and safener. The composition claimed in the suit patent is a synergistic and homogenous composition, demonstrating enhanced and efficient weed control with a sustained impact on weed growth. The said composition significantly reduces the phytotoxicity and provides improved efficacy, ultimately leading to increased crop yield while ensuring effective crop protection.
During the prosecution of the instant suit patent, four pre-grant oppositions were filed. However, all the pre-grant oppositions were dismissed by the Controller of Patents, and eventually, the patent was duly granted to the plaintiff on January 9, 2023. Further, two writ petitions were also filed by Mr. Anand Arya and by M/s Haryana Pesticides Manufacturers Association, respectively, wherein the writ petition filed by Mr. Anand Arya was withdrawn, and the one filed by M/s Haryana Pesticides Manufacturers Association was dismissed by the Court vide order dated January 8, 2024. Subsequently, a post-grant opposition was also filed by M/s Haryana Pesticides Manufacturers Association. The instant suit patent is being commercially worked in India and manufactured and marketed by the product under the name ‘ACM-9’.
Subsequently, in January 2024, the plaintiff came across a product being sold under the name ‘RACER’, manufactured and marketed by Defendant No. 1, Safex Chemicals India Limited. Upon inspection of the product and its packaging, the plaintiff found that the product’s composition was identical to the composition claimed in his suit patent. Upon conducting laboratory tests on a procured sample of the defendant’s product (RACER), the plaintiff discovered the presence of ‘Metribuzin Content – 20.0%’, ‘Clodinafop Propargyl Content – 9.0%’, along with a ‘safener’, identical to the plaintiff’s composition.
Further, upon checking the official websites of Defendant No.1, the plaintiff found that Defendant No. 1 is operating and managing several entities, including Defendant No. 2, Indo Swiss Chemicals Limited, and Defendant No. 3, Smith N Smith Chemicals Limited. Furthermore, on checking the websites maintained by Defendant No. 2 and Defendant No. 3, the plaintiff discovered advertised products under the names of ‘Trophy’ and ‘Jodi No.1’, respectively, having identical compositions to that of the composition claimed by the plaintiff in the instant suit patent.
The plaintiff also discovered that Defendant No. 1 had filed a post-grant opposition on January 8, 2024, which was subsequently withdrawn on January 9, 2024. Therefore, the plaintiff filed an infringement suit against the defendants (collectively referred to as Defendants 1-3) for the unauthorised act of manufacturing, marketing, and offering for sale of the product as claimed in the suit patent.
Plaintiff’s Contention
The plaintiff contended that the essential feature of the suit patent lies in the homogeneous wettable powder composition of two herbicides, ‘Clodinafop Propargyl (9%) and Metribuzin (20%)’, in a specific ratio of ‘1:2.2’, and the ‘dye or pigment’ is merely an optional ‘adjuvant/excipient’. Thus, the plaintiff contended that the doctrine of equivalents should apply since the ‘pith and marrow’ of the subject invention has been copied.
Defendant’s Contention
Defendant contended that they had been lawfully manufacturing and marketing the composition under the brand names ‘RACER’ and ‘JODI No.1’, comprising ‘ClodinafTTop Propargyl 9%’ and ‘Metribuzin 20% WP’ since June 2020, after obtaining registration under Section 9(4) of the Insecticides Act, 1968. The defendant also contended that the composition manufactured and sold by them does not contain any pigment, dyeing agent, or colouring substance, which is being explicitly claimed as an essential feature of the plaintiff’s composition.
Furthermore, the defendant also stated that the complete specification of the plaintiff’s suit patent describes the dyeing agent as a key component, as the presence of the dyeing agent ensures visual homogeneity of the composition. The defendant also highlighted the fact that there is not a single embodiment or example in the complete specification wherein dye has not been used, and thus, the dyeing agent is not an optional or auxiliary component; rather, it is an integral part of the composition claimed by the plaintiff in the suit patent.
Key Issues Before the Court
The key issues which arose before the Court were as follows: “Whether the dyeing agent or pigment is an essential element of the suit patent”. Another issue before the Court was to ascertain “whether the infringement ought to be based on the ‘Doctrine of Equivalents’”.
Court Observation and Findings
The Court observed that the complete specification, including the claims of the suit patent, clearly indicates that the ‘dyeing agent or pigment’ is not merely incidental but rather serves a specific functional purpose, i.e., it enables visual identification of treated areas. Accordingly, in the absence of a clear disclaimer, the Court noted that the ‘dyeing agent’ must be treated as integral to the inventive concept. The Court also observed that the claim mapping of the plaintiff’s composition vs the defendant’s product reveals that the defendant’s product does not contain the ‘dyeing agent or pigment’. Hence, the Court noted that the present case is not a case of ‘literal infringement’; rather, the infringement analysis ought to be based on the ‘Doctrine of Equivalents’.
Secondly, the Court also relied on the fact that the plaintiff, during the prosecution history, emphasised the ‘dyeing agent’ as an essential feature and even obtained the suit patent over it. Accordingly, the principle of estoppel plays an important role here, as the statements or submissions by the plaintiff during the prosecution history would apply as an estoppel for infringement analysis.
Accordingly, the Court stated that the balance of convenience is in favour of the defendants and against the plaintiff and, consequently, dismissed the application for an interim injunction. The Court also directed the defendant to maintain accounts of manufacture and sale.
Conclusion
The Court, in the present case, has emphasised the relevance of the “inventive concept” of the suit patent application. The Court also emphasised the importance of claim construction, functional elements of the independent claims, and implications of prosecution history estoppel. The present case also reaffirmed the principle and scope of the ‘Doctrine of Equivalents’ followed in the case of Patent infringement analysis.
Authors: Manisha Singh and Vaneet Kaur
First Published by: Mondaq here