“Clear the Way” Before Market Entry: Calcutta High Court Grants Interim Relief in NOCIL v. Finorchem

On October 7, 2026, the Hon’ble Calcutta High Court in NOCIL Ltd. v. Finorchem Ltd. & Anr. [IA No: GA-COM/1/2024 in IP-COM/25/2024] stated that companies intending to enter a market with a process potentially covered by an existing patent should address potential patent obstacles before commencing operations, rather than waiting to be sued for infringement.

The Court noted that Finorchem had failed to take steps to address the potential patent conflict before the suit was filed and that its manufacturing process was prima facie substantially similar to NOCIL’s patented processes.

NOCIL holds three Indian patents for processes used to manufacture 4-Aminodiphenylamine (4-ADPA), a chemical used as an antioxidant in rubber and polymer applications and as an intermediate in producing other antioxidants. It alleged that Finorchem’s process incorporated the essential features of its patented methods and that a former employee, who had signed a non-disclosure agreement (NDA) concerning the 4-ADPA project, had access to its confidential technical information.

Citing Smith Kline Beecham v Generics UK Ltd [2001] 10 WLUK 610, AstraZeneca AB v Glenmark Pharmaceuticals Europe Ltd [2025] EWCA Civ 480 and Eisai Co Ltd v Satish Reddy, 2019 (79) PTC 568, the Court reiterated the “clear the way” principle, under which a prospective entrant should address potential patent obstacles before commencing operations. Before the suit was filed, Finorchem had not pursued any of the statutory remedies available to it, including pre-grant opposition under Section 25(1) of the Patents Act, 1970, post-grant opposition under Section 25(2), a declaration of non-infringement under Section 105, relief against groundless threats under Section 106, or revocation under Section 64. The Court considered this failure relevant to its assessment of interim relief.

Comparing the processes, the Court found common steps, including the reaction of aniline with tetramethylammonium hydroxide (TMAH), use of continuous reactors, hydrogenation and recovery of 4-ADPA. It noted that the end products were identical and the Environmental Impact and Risk Assessment (EIRA) reports virtually identical, with NOCIL’s report preceding Finorchem’s. Finorchem had disclosed at least three different versions of its process. The Court found that, contrary to the catalyst distinction drawn in its EIRA report, Finorchem proposed to use the same catalyst as NOCIL, and considered the proposed amendments to Finorchem’s patent application—including replacing a specified molar ratio with “predetermined ratio” and making the second hydrogenation step optional—as attempts to create an appearance of difference.

Relying on Raj Parkash v Mangat Ram Chowdhry (1977 SCC OnLine Del 33), the Court said infringement is assessed by examining the “pith and marrow” of the patented process—its essential inventive features—rather than trifling variations. NOCIL’s expert evidence on the similarities between the processes remained uncontroverted.

On validity, the Court said that a patent grant does not by itself establish validity, reading Sections 12 and 13(4) of the Patents Act together and relying on Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries [(1979) 2 SCC 511]. Under Section 107, a defendant can raise any ground of revocation under Section 64 as a defence. Although a patent may be challenged, the Court found that Finorchem had failed to raise a credible challenge. It considered the patents’ examination and commercial exploitation over the years, noted that a challenge to NOCIL’s equivalent US patents had been dismissed, and observed that separate prior-art references could not simply be combined to establish that the patented process was already known.

On Section 104A, which shifts the burden of proof in specified process-patent infringement cases subject to statutory conditions, the Court rejected the argument that NOCIL must first establish validity before the burden shifts, holding that once the products are shown to be identical, the defendant must prove that its process is different. It distinguished Natural Remedies v. Indian Herbs Research (2011 SCC OnLine Kar 4561), involving non-identical products after trial, and Hindusthan Lever v. Godrej Soaps (1996 SCC OnLine Cal 145), where the patent was recent and unworked and the validity challenge preceded the suit.

On confidentiality, the Court examined the NDA, which specifically covered the 4-ADPA project, and appraisal and assessment reports signed by the former employee concerning plant operations. His qualifications and the documentary record contradicted Finorchem’s claim that his role was administrative rather than technical. He did not personally affirm any pleading, and the circumstances surrounding his engagement by Finorchem also weighed against the respondents. The Court found that the material prima facie indicated a breach of confidentiality and of the NDA, which Finorchem had intended to procure, holding that infringement and confidentiality claims are not mutually destructive. It also noted that Finorchem had applied for its own process patent after the suit was filed and had not contemporaneously disclosed its relationship with the former employee.

Finding a strong prima facie case, irreparable injury and a balance of convenience in NOCIL’s favour, the Court granted interim relief, noting that Finorchem had not yet commenced commercial production and that the mere filing of a counterclaim was insufficient to prevent protective relief. Under Section 48(b), a process patentee has the exclusive right to prevent third parties from using the patented process. The Court clarified that the ultimate question of infringement would be decided at trial after assessment of expert evidence.