By Jigyasa Pareek

In patent claim drafting, the term “comprising” carries significant weight. Courts across jurisdictions, including India, have recognised that “comprising” is an open-ended term it denotes that a claim includes the listed elements but does not exclude the presence of additional, unrecited elements. This contrasts with restrictive terms like “consisting of” which confine the claim strictly to what is enumerated.

The Delhi High Court had previously considered this nuance in F. Hoffmann-La Roche Ltd. vs Cipla Ltd. [2015 SCC OnLine Del 13619]. There, the Court noted that the use of “comprising” makes a claim enabling rather than limiting, it extends the protective ambit of a claim to minor variations or equivalents of the claimed invention. In practical terms, if a patent claim “comprises” a particular composition, it covers that formulations of components where the composition appears with other permissible components. This interpretive principle often becomes decisive in infringement litigation.

This interpretive rule was central to the Court’s recent decision in Frimline Private Limited & Anr. vs K-Smatco Lifesciences Private Limited & Ors. [CS(COMM) 808/2025; 2025:DHC:7535; decided 29 August 2025]. The dispute involved Indian Patent number 382949, entitled “A Pharmaceutical Composition for Anaemia”. The patent covered a synergistic composition of Lactoferrin and a Guanosine Nucleotide (or its pharmaceutically acceptable salt), designed for the treatment of iron deficiency anaemia and related conditions.

Frimline, the patentee, had commercialised the invention under well-known brands such as FERRONOMIC and FERRONEMIA PLUS. In July 2025, they discovered that K-Smatco was marketing a product branded FERROTOK PLUS with an almost identical formulation and range: Lactoferrin 50 mg, Disodium Guanosine 5-Monophosphate (DGMP) 5 mg, and Ferrous Bisglycinate 27 mg. Frimline alleged infringement, supported by claim mapping and chemical analysis. The Defendants countered that their use of (DGMP) fell outside the scope of the suit patent, which explicitly claimed “Guanosine Monophosphate (GMP)” in dependent Claim 2.

This is where the interpretive significance of “comprising” comes into the picture. The Court examined independent Claim 1 and dependent Claim 2 of IN’949, in light of the complete specification. Notably, the detailed description of the invention disclosed DGMP as a preferred embodiment, therefore, as under Section 10(4)(c) of the Patents Act, 1978, the patent scope did cover DGMP. Accepting this position, the Court stressed that the word “comprising” broadened the claim to cover such variants. The Court cited the decision in Roche vs Cipla and established drafting conventions from Terrell on the Law of Patents, reiterating that “comprising” does not mean “only consisting of”.

On this basis, the Court found a strong prima facie case of infringement, noting also that the Defendants had not filed any technical evidence to rebut Frimline’s certificate of analysis. Defendant No. 2, the manufacturer, remained absent despite service, further strengthening the inference of deliberate infringement. Accordingly, an interim injunction was granted restraining the Defendants from manufacturing, selling, or marketing FERROTOK PLUS or any other product falling within the claims of IN’949. The Court also upheld Frimline’s copyright claim, directing the Defendants to withdraw copied website content.

The decision illustrates how the single word “comprising” can decisively tilt the scales in a patent dispute. By affirming that DGMP was encompassed within a claim “comprising” GMP, the Court reinforced the principle that patentees are entitled to protection not only for the precise embodiment spelt out in the claim but also for variations disclosed in the specification. For pharmaceutical patentees, where salts, isomers, and derivatives are commonplace, this interpretive stance provides a broader safeguard against infringers seeking to evade liability through minor modifications.

At the same time, the case highlights the importance of careful patent drafting and thorough disclosure. Frimline’s foresight in expressly including DGMP in the specification enabled the Court to straightforwardly link the Defendants’ product to the patent.