|
Patent landscape, scope, and claims: |
US Patent 8,168,663: Scope, Claims, and US Landscape
What does US 8,168,663 claim?
US 8,168,663 is a US patent that claims salt forms and salt-based pharmaceutical compositions centered on a specific benzoxazole core:
- Core compound named in the claims: 6-Carboxy-2-(3,5-dichlorophenyl)-benzoxazole
- Claim 1 (product-by-salt): “A pharmaceutically acceptable salt” of that compound
- Claim 2 (specific counterion): The pharmaceutically acceptable salt of claim 1 that is an N-methyl-D-glucamine (often abbreviated as meglumine) salt
- Claim 3 (composition): Pharmaceutical composition comprising the salt of claim 1 plus a pharmaceutically acceptable carrier
- Claim 4 (composition + specific salt): Pharmaceutical composition comprising the N-methyl-D-glucamine salt of claim 2 plus a pharmaceutically acceptable carrier
Claims map (what is covered)
| Claim |
What is claimed (scope type) |
Core requirement |
Limitation strength |
| 1 |
Product-by-salt (generic counterion) |
Salt of 6-Carboxy-2-(3,5-dichlorophenyl)-benzoxazole |
Medium: broad “pharmaceutically acceptable salts” class |
| 2 |
Product-by-salt (specific counterion) |
N-methyl-D-glucamine salt |
High: single counterion identity |
| 3 |
Composition (salt + carrier) |
Salt of claim 1 + pharmaceutically acceptable carrier |
Medium: “any carrier” opens formulation latitude |
| 4 |
Composition (salt + carrier) |
N-methyl-D-glucamine salt + pharmaceutically acceptable carrier |
High: both salt identity and formulation are constrained |
What is the effective claim scope?
1) Salt-scope breadth (Claim 1)
Claim 1 covers any “pharmaceutically acceptable salt” of the named benzoxazole acid. Practically, that reads as coverage for counterions commonly considered pharmaceutically acceptable for carboxylic acids (e.g., base-derived salts) and other salt classes permitted by the patent’s own salt definition in the specification (the specification typically lists specific salts even when the claims are generic).
The scope hinge is the phrase “pharmaceutically acceptable salt.” If the specification lists a set of salts and defines “pharmaceutically acceptable,” that definition usually constrains the real-world boundaries of Claim 1.
2) Counterion specificity (Claim 2)
Claim 2 isolates N-methyl-D-glucamine as the counterion. That typically creates a clean infringement test for a generic entrant:
- A product that uses meglumine to form a salt of the specified benzoxazole meets the claim element.
- Avoidance by changing only the counterion would typically attempt to escape Claim 2 while potentially still landing within Claim 1 (if the alternative counterion is still “pharmaceutically acceptable” under the patent’s framing).
3) Composition scope (Claims 3 and 4)
Claims 3 and 4 cover formulations where the active ingredient is the claimed salt form.
Key points for landscape interpretation:
- Carriers are not limited by type in the claim text provided. That means formulation work that keeps the same salt and stays within standard carrier categories is still within scope.
- If a competitor changes the salt form but keeps the same benzoxazole free acid or another derivative, they may avoid the salt-specific claims.
How broad are the claims versus typical patent patterns?
This patent follows a common US strategy: claim salt forms rather than the free base/acid entity.
Practical breadth comparison
- Narrowest: Claim 2 and Claim 4 (meglumine salt, with optional carrier in Claim 4).
- Broader: Claim 1 and Claim 3 (generic pharmaceutically acceptable salts; formulation broadness via “carrier”).
Because the core compound identity is explicitly recited in the claims, this is not a “class of benzoxazoles” patent. The scope is anchored to one compound name.
What does “scope” imply for infringement design-arounds?
Potential design-around levers (within this claim set)
A competitor trying to avoid infringement while keeping pharmacology constant would generally use one or more of these levers:
-
Counterion change
- Replace N-methyl-D-glucamine with a different counterion.
- This targets Claim 2/4 avoidance.
- Claim 1/3 could still be implicated if the new counterion is within the “pharmaceutically acceptable salts” boundary as framed by the specification.
-
Avoid salt formation
- Use the free acid form, or a different solid form not characterized as the claimed salt.
- This is typically the most direct route out of a salt-by-salt claim set, but it may create other patent issues depending on overlapping patents for the free acid or crystal forms.
-
Formulation carrier changes alone
- Changing excipients alone usually does not avoid claims 3/4 if the salt identity remains the same.
What is not in scope based on the claim text provided
- No claim language here covers polymorphs (crystal forms) or hydrates/solvates of the salt.
- No claim language here covers specific processes of making the salt.
- No claim language here covers therapeutic methods (dose, indication, regimen).
So the risk profile for a generic entrant is primarily about salt identity and whether the active ingredient in the proposed product meets the salt claims.
What is the likely “patent landscape” role of this patent?
Even without the full prosecution history and specification details, the claim structure indicates the patent plays a typical role in the lifecycle:
- It protects a later-stage solid-state improvement (a salt form) rather than the original benzoxazole entity.
- It can extend market protection beyond the original compound filing by obtaining enforceable rights on a specific physicochemical form that may be used for improved solubility, stability, or manufacturability.
Landscape positioning
| Layer of protection |
What it typically covers |
How 8,168,663 fits |
| Compound or scaffold |
The core entity |
Not claimed here; the benzoxazole scaffold is referenced, but the patent claims salt forms |
| Salt forms |
Counterion-specific protection |
Central to this patent (Claims 1 to 4) |
| Solid-state variants |
Polymorphs/hydrates/solvates |
Not explicitly claimed in the provided claim set |
| Formulation and methods |
Dosing and compositions |
Formulations are covered (carrier + salt) but method claims are not present in the provided set |
What competing products and generic strategies does this claim set influence?
1) If a competitor files an ANDA or 505(b)(2) using the meglumine salt
- Claim 2 (and Claim 4 for formulations) becomes a direct barrier.
- The competitor would need to either (a) obtain a license, (b) wait out expiration, or (c) file an alternative product that does not contain the claimed salt.
2) If a competitor uses a different salt
- Claim 2/4 may be avoided.
- Claim 1/3 still create potential risk if the alternative counterion is treated as “pharmaceutically acceptable” and if the specification does not narrow that term.
3) If a competitor uses the free acid
- The salt claims are avoided on their face.
- The landscape then shifts to patents covering the free acid, its polymorphs, and its solid-state behavior, none of which are stated in the provided claim excerpt.
Scope details that matter for enforcement
Claim language elements
For a clean legal read of the claim scope:
-
“pharmaceutically acceptable salt”
This limits the counterions to those the patent frames as acceptable. The breadth of this term depends heavily on the specification. (In litigation, the specification and prosecution history usually control how broadly this phrase is interpreted.)
-
“compound 6-Carboxy-2-(3,5-dichlorophenyl)-benzoxazole”
The counterion salt must be of that specifically named compound. Generic entrants cannot swap in a different analog and stay outside scope.
-
“pharmaceutical composition” with “pharmaceutically acceptable carrier”
This is broad. Carriers include typical excipients (binders, diluents, disintegrants, etc.). The claim does not specify a dosage form type.
What you should expect in related patents within the same landscape (typical patterns)
Without adding external record detail, the most predictable adjacent patent families (in the common benzoxazole-salt lifecycle) are:
- Salt family continuation: other counterions (e.g., different basic salts for the same acid) claimed separately.
- Crystalline form patents: polymorph, hydrate, solvate variants of the same salt.
- Composition patents: additional formulation claim sets, sometimes specifying dosage forms like tablets/capsules or release profiles.
- Process patents: methods of preparing the salt and isolating the solid form.
This matters because even if 8,168,663 is avoided by counterion change, the product can still be blocked by a nearby solid-state or formulation patent.
Key Takeaways
- US 8,168,663 protects salt forms of 6-Carboxy-2-(3,5-dichlorophenyl)-benzoxazole and formulations of those salts.
- Claim 1 and Claim 3 are counterion-broad but limited to “pharmaceutically acceptable salts.”
- Claim 2 and Claim 4 lock in N-methyl-D-glucamine (meglumine) as the specific counterion, creating the tightest infringement boundary.
- Carrier substitutions alone do not avoid the composition claims; salt identity drives scope.
- The claim set is not written as polymorph, hydrate/solvate, process, or method coverage based on the provided claim text; landscape risk therefore concentrates on solid-state form and salt selection.
FAQs
-
Does US 8,168,663 cover the free acid form of the benzoxazole?
Based on the provided claim text, the patent claims salts and compositions containing salts, not the free acid itself.
-
If a competitor makes a different salt of the same benzoxazole, does it avoid the patent?
It may avoid Claim 2/4 if the counterion is not N-methyl-D-glucamine, but it can still fall within Claim 1/3 if that counterion is treated as a “pharmaceutically acceptable salt.”
-
Are the formulation claims limited to a particular dosage form?
The provided claims do not specify dosage form type. They cover a composition containing the claimed salt and a pharmaceutically acceptable carrier.
-
Can a formulation avoid infringement by changing excipients only?
If the active ingredient remains the claimed salt (Claim 1 or Claim 2 salts), excipient changes alone generally do not remove coverage.
-
What is the most enforceable claim in practice?
Claim 2 (and Claim 4 for formulations) because they specify the exact counterion: N-methyl-D-glucamine.
References
- United States Patent No. 8,168,663. Claims as provided in the prompt.
More… ↓
⤷ Start Trial
|
