Introduction
Defendants are sometimes hauled into patent infringement proceedings for doing nothing more than using methods that existed long before the patent in question was filed. That is not infringement; that is history being used against them. At its core, the defence rests on something refreshingly straightforward: you simply cannot patent what the world already knows. If someone has been sued for infringement but was only ever working with ideas and techniques that were freely available to anyone, it seems fundamentally unfair to treat them as a copycat. And courts, over the decades, have agreed.
The technical term for this pre-existing body of knowledge is “prior art.” The logic follows naturally: if the features a patent claims as its own were already out there before the application was ever filed, the patent probably shouldn’t have been granted in the first place. A valid patent must clear up three fundamental hurdles — it must be novel; it must have utility, and it must be capable of industrial application. These are not mere formalities; they are the conditions on which society agrees to grant a temporary monopoly to an inventor. So how can anyone be punished for using something that was never truly new?
What makes the Gillette Defence particularly interesting is how it has traveled, from a dispute about razor blades in an English courtroom in 1913 all the way to pharmaceutical patent wars in Delhi, cable TV signal cases in London, and insecticide disputes before the brand-new Unified Patent Court in Europe. Along the way, courts have wrestled with how much evidence a defendant actually needs to pull it off, what happens when patent claims are stretched beyond their literal meaning, and whether the defence can survive in a legal world that now recognises the doctrine of equivalents.
This article works through all of that: the origins, the mechanics, the recent cases, and what the defence demands of anyone hoping to rely on it.
The 1913 House of Lords Decision
The defence is known as Gillette Safety Razor Co. v. Anglo-American Trading Co.[1], a House of Lords decision of 1913. A patent for improvements in safety razors had been granted in 1902. The competitor, when sued by the patent holder for patent infringement, claimed that its blade was not flexible at all, that being the very feature that distinguished the patented design. The House of Lords ruled in favour of the defendant, with Lord Moulton stating what has become one of the most frequently cited passages in patent jurisprudence:
‘In my view, it is possible to show the defendant’s right to succeed in this matter without looking at the specifications of the plaintiff’s letters patent. A strong legal defence is the claim that the alleged infringement was not new at the time of the plaintiff’s letters of patent.’
The logical trap that the Gillette Defence creates for the patent holder is what gives it its power. This is how the squeeze operates:
The patent will unavoidably read onto the prior art if its claims are interpreted wide enough to include the defendant’s goods or technique, rendering it invalid for lack of originality. On the other hand, the defendant’s product will not be covered at all if the claims are interpreted narrowly enough to avoid the prior art and yet be valid, indicating that there is no infringement.
As Lord Moulton famously put it, the patent holder is thus caught between the horns of a dilemma: either the patent is void, or there is no infringement. Regardless of the patentee’s choice, the defendant prevails.
This also clarifies the conceptual differences between a simple invalidity challenge and a GilletteDefence. A general invalidity argument makes a broad attack on the patent, claiming that the invention was not innovative, was obvious, or did not meet the conditions for patentability. The Gillette Defence is more focused. It doesn’t always aim to render the patent unenforceable. It merely states, “My particular product or technique is substantially equivalent to anything that existed before the patent’s priority date, regardless of what this patent may or may not cover in the abstract.” I am not accountable for any infringement. The defendant wants protection for themselves because what they are doing is in the public domain; they are not attempting to revoke the patent for everyone.
As Terrell on Patents has put it simply: “Since no relief could be obtained in respect of an invalid patent, if the defendant could prove that the act complained of was merely what was disclosed in a publication that could be relied on against the validity of the patent, without any substantial or patentable variation having been made, he had a good defence.”
Statutory Framework in India
The Gillette Defence is incorporated within the grounds for revocation under Section 64 of the Patents Act, 1970, although it is not a separate procedural procedure in India. Section 64(1)(e) and (f) permit a patent to be cancelled if the invention was publicly known or used in India before the priority date or if it was anticipated by a previous publication. The Gillette Defence’s logical structure is duplicated inside the statutory framework when a defendant asserts these grounds in response to an infringement action under Section 107, which allows any basis under Section 64 to be utilized as a defence.
Accordingly, in Indian litigation, bringing up the Gillette Defence is practically the same as claiming that the invention is not new, given certain previous art that the defendant is using. The defendant must identify the prior art, show how their procedure or product relates to it, and contend that there is no patentably significant difference between what they are doing and what was previously in the public domain.
Early Indian Cases
The Gillette Defence was first acknowledged and used by an Indian court in Ravi Raj Gupta v. Acme Glass Mosaic Industries (1996)[2]. The defendant contended that it was employing a method previously outlined in an outdated, expired patent while being accused of replicating a tile-making process. The defendant argued that this was not creative because there was only a slight fluctuation in the heating temperature. Considering the prior art defence, the Delhi High Court concluded that the plaintiff’s patent was prima facie not an “invention” under Section 2(j) of the Patents Act and declined to issue an interim injunction.
The case established a crucial early principle: if proven prima facie, the Gillette Defence could be used at the interim injunction stage to deny the plaintiff’s emergency relief without necessitating a full trial. One of the doctrine’s most practically important features is still its procedural utility.
Soon after, the case of Hindustan Lever Ltd. v. Godrej Soaps Ltd. (1996)[3]emerged. Godrej was accused by Hindustan Lever of stealing the proprietary recipe for its “VIGIL” soap. Godrej claimed that HLL’s invention lacked any innovative basis by citing an earlier American patent that revealed the same formula. While granting HLL a temporary injunction, the Calcutta High Court made it clear that the Gillette Defence would need to be thoroughly investigated during the trial. It acknowledged the legal validity of the defence while pointing out that a preliminary ruling in favour of the patentee at the interlocutory stage did not bar the defendant from succeeding at a full hearing. The case upheld the rule that the plaintiff’s acquisition of a patent did not justify the defence’s dismissal at the threshold.
The UK: Modernisation and the Doctrine of Equivalents
The Gillette Defence has continued to change in the UK in response to advancements in patent claim construction law. The Supreme Court’s ruling in Actavis UK Ltd v. Eli Lilly and Company (2017)[4] brought a formal theory of equivalents to English patent law for the first time, marking the biggest recent change. According to the Actavis framework, a technique or product may violate a patent even if it does not fit within a typical interpretation of the claim language if it accomplishes the same goal similarly.
The Intellectual Property Enterprise Court had the chance to explicitly address this issue in Technetix BV v. Teleste Ltd (2019)[5]. A patent for cable tap devices used to distribute television signals was at issue in this case. Teleste contended that if its product lacked innovation or an inventive step beyond the previous art, it should be entitled to a defence even if it fits within the patent scope under the law of equivalents. According to Hacon, it would be “surprising” if the Supreme Court in Actavis had intended to renounce the long-standing rule that a patent holder cannot stop someone from doing something that is already legal in the public domain. He brought up the US “ensnarement” theory and the German “Formstein” defence, which are comparable safeguards that accomplish the same goal in countries that have had a concept of equivalents for a lot longer. The Gillette Defence may serve as a stand-alone check on the overuse of the law of equivalents in future English litigation, even though his findings were obiter (the patent was deemed invalid independently).
This question remains unresolved with pending authoritative guidance from the Court of Appeal or the Supreme Court, making it one of the more live debates in UK patent law.
Canada: The Limits of the Defence
The Federal Court of Appeal of Canada offered a significant analytical explanation of the Gillette Defence in Western Oilfield Equipment Rentals Ltd v. M-I LLC (2021)[6], which is a helpful warning. Justice Locke reaffirmed the defence’s traditional formulation, which states that a defendant can prove non-infringement or invalidity by demonstrating that the allegedly infringing product is identical to or not patentably distinct from prior art. However, he emphasized that the defence is “typically unhelpful” unless the factual foundation is precisely established.
The court emphasized that in order to establish that any claims that are sufficiently broad to cover the accused product will inevitably read onto the prior art, the defence requires the defendant to show, with precision, that the accused product relates to the prior art to a sufficient degree. The defence collapses into nothing more than a nebulous challenge to validity when the defendant is unable to clearly demonstrate this, which necessitates a distinct evidentiary basis.
The Gillette Defence is a logically strong weapon, but its effectiveness depends on the caliber of the supporting previous art evidence, as the Canadian approach illustrates.
The Unified Patent Court: A New Frontier (2024–2025)
The Unified Patent Court (UPC), which started operating as a central patent litigation tribunal across participating EU member states in 2023, has seen the most recent and globally significant development in Gillette Defence law. The Gillette defence is strong because it is based on a straightforward but essential fact of patent law: something that was public at the time of the invention filing or priority date cannot be protected by a valid patent. To build doctrine at the new court, litigants and justices have started referencing significant UK precedents, such as the Gillette Defence, while the UPC develops its case law.
One of the first UPC first-instance rulings to directly address the defence was SodaStream Industries Ltd. v. Aarke AB[7]. SodaStream claimed that its European patent EP 1793917, which described a carbonator with a safety mechanism to collect flying glass particles in the event that a glass container that exploded under pressure was identical to Aarke’s Carbonator Pro. Aarke used the Gillette Defence, claiming that the patent’s claims could not apply to its Carbonator Pro because it was essentially identical to two products that were issued before the priority date in earlier US patents.
In particular, the locking mechanism in Aarke’s product that prevented glass fragments from escaping was conceptually similar to SodaStream’s invention, not the earlier designs. The UPC panel declined to apply the Gillette Defence on the facts, finding that the Carbonator Pro was not truly equivalent to the prior US patents in the way that mattered. Even if the UPC rejected the Gillette Defence in this case, this does not guarantee that it will be in others, particularly when the facts warrant its application. The panel’s reasoning was instructive: it made sure the interpretation was distinct from the earlier patents by using the prior art as a reference while constructing the claims.
India’s Recent Landmark: FMC Corporation v. Natco Pharma (2025)
The Delhi High Court’s ruling in FMC Corporation & Ors. v. Natco Pharma Limited in November 2025[8]was the most important current expression of the Gillette Defence in Indian patent law. The case, which involves an insecticide patent that is soon to expire[9], is both practically significant and doctrinally noteworthy because it shows how Indian courts are currently using the defence in intricate, multi-layered pharmaceutical and agrochemical patent disputes.
Natco contended that FMC had created a “patent thicket” comprising more than 40 patents pertaining to the evergreen chemical cyantraniliprole and its derivatives. It argued that because the intermediate had previously been claimed in FMC’s prior invention IN’104, which has a priority date of January 22, 2002, Claim 12 of IN’645 was invalid. Additionally, Natco invoked the Gillette Defence of non-infringement, arguing that the contested product did not violate the suit patent since it was based on expired prior art.
There was a lot of procedural complexity in the dispute’s background. Since 2022, the parties have been involved in several lawsuits pertaining to the Chlorantraniliprole and Cyantraniliprole patent families, including ones in which FMC was refused temporary injunctions over the patent’s method claims. In order to challenge Claim 12, Natco first filed a revocation petition in 2023, received regulatory permissions prior to commercialization in 2025, and claimed that by contacting authorities and courts before to product launch, it had “cleared the way”—a strategy that is becoming more and more common in patent battles.
FMC’s request for an interim injunction was denied by the Delhi High Court. The court determined that Natco had presented a plausible prima facie challenge to the validity of Claim 12 on the grounds of lack of novelty under Section 64(1)(e) of the Patents Act, 1970[10], as well as anticipation by prior claiming under Section 64(1)(a). The court also pointed out that there were just a few weeks left until the suit’s patent expired and that FMC’s Chinese patent counterpart had already been revoked, both of which strongly opposed the granting of emergency relief.
The most developed recent expression of the Gillette Defence in India is seen in the FMC v. Natco ruling. It shows that, with a strong evidentiary basis, Indian courts are now fully familiar with the reasoning of the concept and prepared to apply it strictly in technically challenging instances. Additionally, it shows that judges are more aware of patent evergreening, which is the practice of extending monopoly protection through multiple submissions, and are prepared to closely examine such tactics.
Evidentiary Demands: The Indian Standard
The evidential requirement is one of the most significant practical differences between the Indian and UK approaches to the Gillette Defence. A well-crafted argument pointing to a particular piece of previous art has frequently been sufficient to affect the decision at the interlocutory stage, and courts in the UK have viewed the defence as a useful instrument for effectively resolving patent disputes.
On the other hand, Indian courts have always required more proof. The technical documentation proving the prior art needs to be precise and comprehensive. The relationship between the defendant’s process or product and the prior art is usually explained by expert testimony. The actual previous art must be carefully located and shown to be publicly available prior to the patent’s priority date.
This higher threshold makes sense. In India, disagreements involving uneven resources are common in patent litigation, with local businesses or generic manufacturers on one side and international pharmaceutical or technology corporations on the other. The courts have acknowledged that valid patent rights may be compromised if a loosely phrased previous art argument is accepted without rigor. However, as the FMC v. Natco ruling shows, Indian courts are entirely capable of using the Gillette Defence to reject a claim for interim relief when the prior art is well-established and the defendant’s argument is well-prepared.
Conclusion
In 1913, a disagreement over razor blades gave rise to the Gillette Defence — proof that even mundane disputes can leave a lasting mark on legal history. Over a century later, it remains one of the most logical doctrines in patent law, which is rather impressive for something that started with a shaving kit. Courts from New Delhi to the Hague have stubbornly refused to let patent holders monopolise what was already publicly known, and the Gillette Defence has been the instrument of that refusal. History, it turns out, has a reliable habit of showing up in court —briefcase in hand.
The views expressed are personal.
Notes:
[1] Gillette Safety Razor Co. v. Anglo-American Trading Co. (1913) 30 RPC 465 (HL).
[2] Ravi Raj Gupta v. Acme Glass Mosaic Industries, AIR 1996 Del 83.[3] Hindustan Lever Ltd. v. Godrej Soaps Ltd., AIR 1996 Cal 367.
[4] Actavis UK Ltd v. Eli Lilly and Company [2017] UKSC 48.
[5] Technetix BV & Ors v. Teleste Ltd [2019] EWHC 126 (IPEC).
[6] Western Oilfield Equipment Rentals Ltd v. M-I LLC, 2021 FCA 24.
[7] SodaStream Industries Ltd. v. Aarke AB, UPC Court of First Instance (2024–2025).
[8] FMC Corporation & Ors. v. Natco Pharma Limited, CS(COMM) 607/2024, Delhi High Court, decided 17 November 2025.
[9] A lapsed patent refers to a patent that has expired, after which the invention enters the public domain and may be freely used by anyone.
[10] Section 64(1)(e) and (f), Patents Act, 1970.
Author Bio
