In patent laws, clarity is not just a formality—it’s a requirement. Ambiguity in patent claims and specifications can lead to dire consequences, from rejections during examination to invalidations in litigation. One of the key factors contributing to such ambiguity is the use of certain words or phrases that can alter the meaning of a term when used in the context of patent claims and specification. These words or phrases are commonly referred to as “patent profanity”. This article explores how seemingly harmless adverbs and general terms/phrases/expressions in patent claims can have a detrimental effect on patent applications. We will also delve into the legal analysis of case laws and practical advice for patent professionals on how to avoid these pitfalls.
The Adverse Impact of Patent Profanity
The use of terms such as chiefly, majority, critical, essential, necessary, solely, only, main, significant, principal, important, fundamental, vital, must, always, needed, etc. are very common in patent applications and are frequently used by the patent drafter. Other such terms or phrases are “preferably”, “advantageously”, “optionally”, “very important feature”, “key feature”, “critical feature”, “necessarily” etc.
The judgement from courts in various jurisdictions have found these terms and phrases as limiting the scope of a claim. These terms and phrases should be avoided in the entire patent application, not just the claims. A limiting statement in the specification can be read into the claims resulting in a narrowed scope. Narrowed claims are more easily designed around by competitors causing the patent to be less valuable. Use of these terms and phrases in a patent specification often opens the door for the argument of the alleged infringer to convince the court to read these limitations into patent claims.
Patent claims are meant to define the boundaries of an invention. They inform the public, including potential competitors, of what is protected and what is not. Therefore, the language used in drafting these claims must be precise. Patent specifications that rely on the aforementioned terms and phrases may create confusion, making it difficult to determine the actual scope of the patent.
In jurisdictions like India, United States, and Europe, patent examiners and courts have repeatedly held that the inclusion of these aforementioned terms and phrases (referred as “patent profanity”) in a patent application limits the scope of a claim.
Case studies indicating the Adverse Impact of Patent Profanity Across Different Jurisdictions
- FMC Corporation v. Natco Pharma Limited, (December 5, 2022) [2022/DHC/005311]
In this case, FMC Corporation claimed that Natco Pharma’s process for manufacturing CTPR infringed on their patented method (patent No. 298645) for preparing Chlorantraniliprole (CTPR), an insecticide, even though Natco used a slightly different chemical i.e., thionyl chloride instead of sulfonyl chloride. The matter was heard by the single Bench and by the Division Bench of the Delhi High Court on appeal.
The claims of the patent No. 298645 of FMC Corporation titled “Method for preparing N-Phenylpyrazole-1-Carboxamides” are directed towards the manufacture of chlorantraniliprole (CTPR) such that process of manufacturing of CTPR could occur in any sequence mentioned in the claims. However, in the description of the patent No. 298645, it is stated that “Sulfonyl chloride compounds preferred for the present method because of their commercial availability include methane sulfonyl chloride (R8 is CH3), propane sulfonyl chloride (R8 is (CH2)2CH3), benzene sulfonyl chloride (R8 is Ph), and p-toluene sulfonyl chloride (R8 is 4-CH3-Ph). Methane sulfonyl chloride is more preferred for reasons of lower cost, ease of addition and/or less waste”.
The use of term “preferred” and “more preferred” with respect to “Sulfonyl chloride” in the description has been interpreted by the single judge and division bench as making the use of sulfonyl chloride an integrated part of the invention and an essential element of the method claim. Thus, when Natco Pharma Ltd. process which used thionyl chloride is compared with claims of patent No. 298645 of FMC Corporation, the comparison is done by restricting the scope of claims of patent No. 298645 of FMC Corporation to “sulfonyl chloride compounds” only. The court held that: “42. We do not consider it necessary to refer to other passages of ‘the detailed description of the invention’ furnished to the Patent Office. Suffice it to state that they also support the aforesaid view that sulfonyl chloride is not reflected as an incidental part of the invention but an integral part. Prima facie, it would be erroneous to consider the suit patent IN’645 as an invention that does not involve the use of sulfonyl chloride”.
This result in rejection of FMC’s claim for patent infringement by Natco Pharma.
- Inpro II Licensing, S.A.R.L. v. T-Mobile USA, Inc., 450 F.3d 1350 (Fed. Cir. 2006)
In this case, Inpro owns a patent “U.S. Patent No. 6,523,079” (the ‘079 patent) which is directed to personal digital assistant (PDA) modules designed to overcome various drawbacks and problems associated with previously available PDA systems. The PDA described in the ‘079 patent includes a user interface (16), a host interface (14) for connection to the host computer and a second external connector (20) for connection to external devices such as printers. Specifically, the PDA includes a thumbwheel controller (18), a user interface (16), a host interface (14) for connection to the host computer, and a second external connector (20) for connection to external devices such as printers. The patent explains that the PDA is designed to run independently by its own internal central processing unit (CPU) until it is connected to a host computer. Upon connection to the host computer, the host CPU takes control and can access the memory and other functional units of the PDA.
Inpro sued T-Mobile for infringement of the ‘079 patent. Specifically, Inpro charged T-Mobile with infringement of claims 34, 35 and 36 of the ‘079 patent. T-Mobile counterclaimed for a declaration of non-infringement and invalidity. In a Markman hearing, the district court construed eight disputed terms of the ‘079 claims. The district court construed “host interface” as “a direct parallel bus interface” as the specification of the ‘079 patent characterizes the direct bus interface as a “very important feature” of the invention, stating that a “direct” connection is necessary to provide “direct” access, which allows for fast communication. Based on the claim construction from the Markman hearing, the district court entered final judgment of non-infringement in favor of T-Mobile. Hence, T-Mobile USA, Inc. avoided penalty by drawing attention to their competitor’s use of the phrase “very important feature” in their patent. As T-Mobile did not list the same “very important feature” in their patent, it was decided that there was no violation.
- Pharmacia & Upjohn Co. v. Mylan Pharm., Inc., 170 F.3d 1373 (Fed. Cir. 1999)
In this case, Pharmacia & Upjohn Company (Upjohn), alleges that defendant, Mylan Pharmaceuticals Inc. (Mylan), has infringed Upjohn’s United States patent 4,916,163 (the ‘163 patent) relating to certain pharmaceutical formulations of the anti-diabetic drug, glyburide. Upjohn alleges that Mylan’s filing of an Abbreviated New Drug Application (ANDA) with the Food and Drug Administration (FDA) constitutes infringement under 35 U.S.C. § 271(e) (2) (A). Upjohn also alleges that Mylan’s commercial manufacture and sale of two of the accused products constituted infringement under 35 U.S.C. § 271(a). Upjohn acknowledges that Mylan has not literally infringed the ‘163 patent and bases its allegations of infringement on the doctrine of equivalents.
Mylan has moved for summary judgment of non-infringement as a matter of law based on principles of prosecution history estoppel. Mylan Pharmaceuticals, Inc. (Mylan) persuaded the court to limit Pharmacia & Upjohn Company’s (Upjohn) claim scope based on Upjohn’s use of “patent profanity” in a communication with the USPTO. Mylan pointed out that in a response to a prior art rejection, Upjohn argued that “the use of spray-dried lactose is a critical feature of the present invention,” and that “the key feature of the present invention is the particular type of lactose employed in the composition.” After considering Mylan’s arguments for a narrow reading of the claims due to Upjohn’s use of the terms “critical feature” and “key feature,” the court interpreted Upjohn’s claim to require spray-dried lactose. Because Mylan’s product lacked this “key feature,” the court found no infringement on Mylan’s behalf.
- Biovail Corp. Int’l v. Andrx Pharm., Inc., 239 F.3d 1297 (Fed. Cir. 2001)
In this case, Biovail corporation international is the exclusive licensee of the US patent No. 5,529,791 (“the ‘791 patent”), which is issued on June 25, 1996 and owned by Galephar P.R,. Inc., Ltd. The ‘791 patent is directed to a once-a-day drug for treatment of hypertension and angina. Biovail markets the drug described in ‘791 under the trade name Tiazac. On June 22, 1998, Andrx filed an Abbreviated New Drug Application (“ANDA”) with the United States Food and Drug Administration (“FDA”) under section 505(j) of FD C Act, for a generic version of Tiazac along with a certification asserting that its ANDA product does not infringe ‘791 patent and that the ‘791 patent is invalid.
On October 7, 1998, Biovail filed an action in the US district court alleging patent infringement pursuant to 35 USC $271€ (2) (A) which provides that it is an act of infringement to submit an application under 505 (j) of the FD C act to submit an application. The district court held a bench trail conducting both claim construction and infringement analyses. During the claim construction, a court first analyses the intrinsic evidence of record – the claims and written description of the patent itself, and, if in evidence, the prosecution history.
It is found that while amending claims during the patent prosecution of ‘791 patent, Biovail included the term “necessarily” in its associated remarks to the USPTO. Andrx capitalized on the use of the term “necessarily” to argue for a narrow claim construction. Andrx argued that Biovail’s patent should be limited based on an argument made in response to a rejection that a bead produced by the claimed extrusion-spheronization process of the ‘791 patent “is necessarily a homogeneous bead composition”.
The court agreed with Andrx, causing Biovail to lose priority for a later-filed application and allowing Andrx to escape infringement.
CONCLUSION
In view of the above case studies, it can be clearly ascertained that by avoiding patent profanity while drafting patent applications, a stronger and more defensible patent can be obtained. To avoid patent profanity, patent drafter should familiarize themselves with aforementioned case laws as well as related similar case laws in different jurisdictions and apply the lessons from them while drafting patent application and during patent prosecution, to avoid patent profanity that courts or patent examiners may deem as limiting the scope of the patent.
