Patent 7,897,623 (US): Scope and Claim Analysis for N-(4-chloro-3-(trifluoromethyl)phenyl)-N′-(4-(2-(N-methylcarbamoyl)-4-pyridyloxy)phenyl)urea Compositions
US 7,897,623 claims a small-molecule urea drug substance defined by a specific chemical structure (including a tosylate salt option) formulated as a pharmaceutical composition and, in narrower dependent claims, as a tablet with generic categories of excipients. The estate is composition-centric: the claims cover drug substance plus pharmaceutically acceptable carrier and dosage-form tablets rather than detailed manufacturing steps, dose regimens, or specific use methods.
What does US 7,897,623 claim: scope of the independent composition claim?
Core coverage (Claim 1)
Claim 1 is an independent composition-of-matter claim directed to:
- Drug substance: N-(4-chloro-3-(trifluoromethyl)phenyl)-N′-(4-(2-(N-methylcarbamoyl)-4-pyridyloxy)phenyl)urea, formula X
- Plus: “a pharmaceutically acceptable carrier”
- Includes: “pharmaceutically acceptable salt thereof”
Claim 1 scope statement (effective boundaries)
This claim is broad in two dimensions:
- Salt-inclusive: It covers the free base and “pharmaceutically acceptable salt thereof,” not limited to tosylate.
- Carrier-inclusive: It covers any pharmaceutically acceptable carrier, which functionally captures oral solid carriers (excipients) and other standard pharmaceutical carriers, unless the carrier is argued not to be “pharmaceutically acceptable.”
What Claim 1 does not cover
- It does not claim a specific route (oral vs. parenteral) except as later narrowed by the “tablet” dependent claims.
- It does not claim specific excipient compositions (only excipient categories in dependent claims 7-8).
- It does not claim dosing instructions, method-of-use, or a therapeutic claim (no regimen limitations appear in the provided claim set).
- It does not claim polymorphs, particle size, coatings, or other physical attributes beyond “tablet” in dependent claims.
Practical implication for freedom-to-operate (FTO)
If the accused product includes the same exact urea structure (or a “pharmaceutically acceptable salt” of it) in a pharmaceutical carrier, it falls within the claim 1 frame. A design-around must usually involve either:
- using a different active (different chemical structure), or
- using a form argued not to be a “pharmaceutically acceptable salt,” and/or
- challenging whether the formulation uses a “pharmaceutically acceptable carrier” as required by the claim (a fact-heavy argument).
Are tosylate salts specifically claimed in US 7,897,623, and how much do they narrow protection?
Claim 2 and Claim 4 (tosylate-specific dependent claims)
- Claim 2: Claim 1 with the salt limited to a tosylate salt of the urea.
- Claim 4: Claim 3 with the salt limited to a tosylate salt.
Interpretation of the dependent claims’ value
- Claim 1 already covers “a pharmaceutically acceptable salt thereof.” Claim 2 creates an explicit tosylate fallback position, typically used to preserve infringement/validity posture if a challenger argues that particular salts are not “pharmaceutically acceptable” or do not meet prosecution-defined scope.
- In litigation, a tosylate product can be asserted against the independent claim 1 as well, but Claim 2 makes the infringement theory cleaner because tosylate is expressly stated.
What Claim 2/4 do not add
- No additional process steps, stability parameters, or tablet-specific constraints are included in the tosylate dependency itself.
- The limitation is essentially salt identity plus carrier/tablet constraints depending on the dependent chain.
What is the difference between “pharmaceutically acceptable carrier” and “physiologically acceptable carrier” in Claims 3-4?
Claims 3-4 introduce a second independent composition variant
- Claim 3 mirrors Claim 1 but substitutes “physiologically acceptable carrier.”
- Claim 4 mirrors Claim 2 but is chained from Claim 3.
How this affects claim scope
- The wording change likely seeks to capture formulations where challengers argue “pharmaceutically acceptable” is too narrow. “Physiologically acceptable” can be argued to broaden allowable excipients/carrier systems as long as they are acceptable in a physiological context.
- Practically, both phrases are commonly construed broadly in pharma contexts. But having both phrases can reduce the risk of a textual noninfringement argument at the claim-construction stage.
Litigation utility
- If “pharmaceutically acceptable carrier” becomes a contested term, Claim 3 provides an alternate path.
- If “physiologically acceptable carrier” is contested, Claim 1 still stands.
Do tablet formulations get explicit protection in US 7,897,623?
Yes. Claims 5-8 narrow to tablets.
Claim 5 (tablet formulation independent-by-dependency)
- A tablet comprising the urea (or salt) and at least one pharmaceutically acceptable excipient.
Claim 6 (tablet + tosylate)
- Claim 5 with salt limited to tosylate.
Claim 7 (tablet excipient categories)
- Claim 5 with excipient category limited to at least one from:
- diluent
- granulating agent
- disintegrating agent
- binding agent
Claim 8 (tablet + tosylate + excipient categories)
- Claim 6 with the excipient categories of Claim 7.
Scope implications
- Claim 5 is a broad tablet claim: “at least one” pharmaceutically acceptable excipient.
- Claim 7 reduces breadth but can still capture many standard tablet formulations (diluent/disintegrant/binder systems are typical).
- Together, the claim set covers:
- tablet dosage form with any acceptable excipient in Claim 5, and
- tablet formulations using typical excipient classes in Claims 7-8.
Design-around options relative to tablet claims
- Avoiding literal infringement by changing dosage form (e.g., capsule, solution, spray) may fall outside “tablet” if construed narrowly.
- Changing to a completely different solid dosage form could be an argument against “tablet” (but actual construction will depend on the patent and the claim term scope).
- Changing excipient types to exclude the categories listed in Claim 7 might avoid Claims 7-8, but Claim 5 still covers “at least one excipient,” so excipient substitution alone is rarely enough.
How strong is the patent estate for composition coverage: what types of claims are missing?
Based on the provided claim set, US 7,897,623 appears to be limited to composition and dosage-form claims. The claim text provided does not show:
- method-of-use claims (therapeutic use, dosing regimen, patient selection)
- manufacturing process claims (granulation process, crystallization, milling)
- polymorph/crystal form claims
- particle size distribution claims
- stability or formulation performance targets
- specific coatings (enteric coating, film coating composition)
- specific dose strength limitations
Impact
This matters because, for generic or biosimilar-style competitive entry risk, composition claims are often the key barrier. But the breadth can also be constrained if the estate lacks additional dependent claims that cover specific physical characteristics or method-of-use/regimen. Without them, challengers can focus on active ingredient differences (chemical structure) or dosage form term construction (e.g., “tablet”).
What generic entry risks exist for products using the same urea core or tosylate salt?
High-risk scenario
- A generic or follow-on product using the same urea structure (same formula X) as the active and formulated into a tablet with standard excipients is at direct risk under:
- Claim 1/2 (composition with carriers, tosylate option)
- Claim 5-8 (tablet, tosylate option, excipient categories)
Medium-risk scenario
- A product uses the same active but in a non-tablet dosage form (capsule, solution, suspension) could avoid Claim 5-8 if “tablet” is construed strictly. But Claim 1/3 (composition with a carrier) can still apply.
Lower-risk scenario
- A product uses a different active (even if mechanistically similar) is likely outside the literal claim because the claims are structure-defined.
- A product uses a different salt where the salt is argued not to be “pharmaceutically acceptable” may still be challenged under Claim 1/3 depending on expert evidence and term construction; Claim 2/4 explicitly protect tosylate, so non-tosylate salts may still face arguments.
Which product variants would likely infringe: free base vs salts vs formulation form?
Likely literal infringement targets
- Free base + any pharmaceutically acceptable carrier: Claim 1 and Claim 3
- Tosylate + any pharmaceutically acceptable carrier: Claim 1/2 and Claim 3/4
- Tosylate + tablet + any excipient: Claim 5/6
- Tosylate + tablet + diluent/granulation/disintegrant/binder: Claim 7/8
Key construction points for infringement analysis
- Whether the accused active is the “N-(4-chloro-3-(trifluoromethyl)phenyl)-N′-(4-(2-(N-methylcarbamoyl)-4-pyridyloxy)phenyl)urea of formula X” exactly.
- Whether the accused dosage form qualifies as a “tablet.”
- Whether the excipient arrangement satisfies the “at least one” excipient threshold (Claim 5) or the excipient-class limitation (Claims 7-8).
What patents are likely adjacent to US 7,897,623: formulation, salts, and process coverage gaps?
The provided text contains only the claims for US 7,897,623. Without the broader family/patent list, the analysis must be limited to what this specific patent covers. Within that limitation, the likely adjacency patterns in this type of portfolio are:
- Salt patents (tosylate or other salts)
- Formulation patents (specific excipient systems, tablet compositions, coatings)
- Solid-state patents (polymorphs, hydrates, solvates)
- Process patents (crystallization, purification)
Given US 7,897,623 includes only broad excipient categories and no solid-state/process features in the provided claims, other patents in the same family (if they exist) would typically carry the additional technical barriers. The absence of those features in these claims means US 7,897,623’s protection is anchored to the chemical entity and generic composition/tablet framing.
What regulatory path does US 7,897,623 most likely block in the US?
For US entry strategies, composition-of-matter patents generally deter:
- ANDA filers seeking approval for the same active ingredient, especially where the ANDA product is in a tablet form or includes the same carrier system.
- Any applicant whose product is designed to match the claimed active ingredient and dosage form.
The provided claim set does not provide details sufficient to tie this patent to a specific FDA approval (no NDA/ANDA linkage in the prompt), so the regulatory analysis must remain at the claim-type level: composition and tablet formulation patents are strong for product-level exclusivity arguments.
Key Takeaways
- US 7,897,623 is composition-centric: it claims a specific urea active ingredient (formula X) with pharmaceutically or physiologically acceptable carriers.
- Tosylate is explicitly claimed via dependent Claims 2 and 4, strengthening enforcement against tosylate products.
- Tablet formulations are expressly covered in Claims 5-8, with Claims 7-8 adding excipient-category limitations (diluent, granulating agent, disintegrating agent, binding agent).
- The claim set, as provided, does not show process, polymorph, or method-of-use coverage, which shifts any additional competitive-entry defenses toward dosage-form scope (“tablet”), active-ingredient identity, and carrier/excipient argumentation.
FAQs
1) Does US 7,897,623 cover the free base and salts or only tosylate?
Claim 1 (and Claim 3) covers the urea plus “a pharmaceutically acceptable salt thereof.” Claims 2 and 4 specifically add tosylate as a dependent fallback.
2) Can a non-tablet dosage form avoid infringement of US 7,897,623?
It can reduce risk of Claims 5-8, but Claims 1 and 3 are not limited to tablets and can still capture a formulation in another dosage form if the same active and carrier requirements are met.
3) Are excipient substitutions enough to design around US 7,897,623?
Not for Claim 5, which requires only “at least one” pharmaceutically acceptable excipient. Excipient substitution may help only against the narrower excipient-category limitations in Claims 7-8.
4) What is the fastest path to analyzing infringement for a candidate generic?
Map the candidate product to: (i) whether the active matches the claimed formula X urea, (ii) whether it uses tosylate or another “pharmaceutically acceptable” salt, and (iii) whether the dosage form is a “tablet.”
5) What claim-construction issues are most likely in disputes over this patent?
The most likely hotspots are “tablet,” “pharmaceutically acceptable carrier,” and whether the accused salt qualifies as “pharmaceutically acceptable” (with “tosylate” being explicit in dependent claims).
References
- United States Patent No. 7,897,623.
