United States Patent 10,973,827: What Claims Cover, What the Scope Reads on, and How the US Patent Estate Likely Blocks Tablet/Combination Generics
US Patent 10,973,827 is a formulation-and-dose specific composition patent in the US that centers on a three-part system: (i) a defined xanthine small molecule (with exact substitution pattern and the (R) stereocenter on the amino-piperidine), (ii) metformin hydrochloride at specified tablet strengths/ranges, and (iii) a basic amino acid, explicitly L-arginine, at controlled levels and ratio to the xanthine, in a film-coated immediate-release tablet with defined excipient ranges and performance requirements.
What is US Patent 10,973,827 actually claiming (independent claim scope and core claim elements)?
Independent claim 1 is directed to a pharmaceutical composition in the form of a film-coated tablet that includes:
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Active xanthine entity (fixed chemical identity)
- 1-[(4-methyl-quinazolin-2-yl)methyl]-3-methyl-7-(2-butyn-1-yl)-8-(3-(R)-amino-piperidin-1-yl)-xanthine
- Present at 0.1–0.5% by weight of the total coated tablet mass.
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Metformin hydrochloride
- Present as 47–85% by weight of the total coated tablet mass.
- Claim 2 further narrows to specific dosage strengths/ranges (100–1500 mg, or listed strengths such as 250/500/625/750/850/1000 mg, and a subset).
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Basic amino acid with intramolecular amino group and alkaline characteristics
- Claim language requires this basic amino acid to suppress degradation of the xanthine.
- Claim 1 describes it functionally, but dependent claims operationalize it:
- Claim 3: L-arginine present at 1–50 mg (or 1–25 mg).
- Claim 5 implicitly ties basic amino acid choice to L-arginine by identifying other excipient species, leaving the amino acid fixed through the earlier dependent path.
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Excipient system with defined ranges and identities (tablet engineering)
The film-coated tablet must include excipients with specified weight percentages (of total coated tablet mass):
- Binder: 3.9–8.1%
- First filler: 2.3–5.9%
- Second filler: 0–4.4%
- Third filler: 0–33%
- Lubricant: 0.7–1.5%
- Glidant: 0.1–0.5%
Dependent claim 5 then locks the excipient identities to typical direct-compression and granulation components:
- First/second/third fillers from D-mannitol, corn starch, pregelatinized starch
- Binder: copovidone
- Lubricant: magnesium stearate
- Glidant: colloidal anhydrous silica
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Film coat
Dependent claim 7 limits the coat formulation conceptually:
- film-coating agent
- plasticizer
- optionally glidant and/or pigments
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Dosage form and release
- Claim 6 and claim 8: film-coated tablet structure includes mono-layer options and specific multi-layer/press-coat variants (via selection language).
- Claim 9: immediate release performance requirement:
- After 45 minutes, in a dissolution test, at least 75% by weight of each xanthine and metformin is dissolved.
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Mechanical robustness and disintegration (hard constraints in claim 10 path)
Dependent claim 10 adds numeric tablet performance and core attributes:
- metformin HCl about 85% by weight of the tablet core
- xanthine about 0.2–0.4% of tablet core
- L-arginine about 2% of tablet core
- crushing strength ≥ 100 N
- friability ≤ 0.5%
- thickness 5.7–8.4 mm
- core weight 590–1180 mg
- disintegration time ≤ 15 min
Practical interpretation of claim scope (what must be present, and what is optional)
- Not optional: the exact xanthine identity, metformin HCl, the basic amino acid function (and via dependent path, specifically L-arginine), film-coated tablet, and excipient ranges at claim 1 level.
- Potentially optional at independent level: type of binder/filler/lubricant/glidant selection (identity is specified by dependent claim 5, but claim 1 only requires the ranges).
- Operationally tight at dependent claim levels: excipient identities (claim 5), mono-layer film structure (claim 8), dissolution threshold (claim 9), and full tablet parameter envelope (claim 10).
Which parts of the formulation are the biggest infringement levers for US Patent 10,973,827?
The strongest “design-around sensitive” components are:
1) The xanthine identity and stereochemistry
The compound name fixes the chemical scaffold and requires the (R)-amino-piperidine stereochemistry. Substituting stereochemistry, altering the ring substituents, or using a different xanthine derivative would typically move outside literal scope.
2) The specific metformin HCl content and strength
Claim 1 requires a broad metformin fraction (47–85% by weight). Claim 2 further narrows by dosage strength (100–1500 mg or enumerated strengths).
A generic could attempt to avoid claim coverage by using a metformin dose strength not in claim 2. But claim 1 still requires metformin to sit within 47–85% by weight in the coated tablet mass. That ratio constraint remains a separate barrier.
3) L-arginine amount and ratio to the xanthine
- L-arginine: 1–50 mg (or 1–25 mg) in claim 3.
- Ratio: xanthine:L-arginine from about 1:20 to 10:1 (with multiple overlapping sub-ranges in claim 4).
The combination of absolute mg range plus ratio provides multiple hooks for literal infringement.
4) Coated tablet excipient ranges
Because claim 1 binds multiple excipient categories by weight percentage ranges, a tablet-engineering generic that changes only one excipient category may still fall inside range coverage.
5) Release and performance parameters
- Immediate release: ≥75% dissolved for both actives at 45 minutes (claim 9).
- Tight physical parameters: hardness, friability, thickness, weight, disintegration time (claim 10).
These are common targets for designing alternative process/formulations, especially if dissolution and mechanical parameters are hard to match.
How does claim 10 narrow the product to a near “spec-sheet” tablet?
Claim 10 is a high-specificity dependency that, if asserted, typically forces the accused product to match a bundle of measurable properties simultaneously:
A generic could still potentially argue that even if composition overlaps, it avoids claim 10 by not meeting one or more numerical performance constraints. But this shifts the dispute toward test data and formulation equivalency arguments.
What additional limitations do claims 5, 6, 7, and 8 add to the formulation definition?
Claim 5: excipient identity lock-in
Claim 5 narrows the excipient identities to:
- fillers: D-mannitol, corn starch, pregelatinized starch
- binder: copovidone
- lubricant: magnesium stearate
- glidant: colloidal anhydrous silica
This creates a “materials” pathway for claim coverage. A generic not using these exact excipient species could still try to avoid claim 5 while staying within claim 1 excipient ranges, but assertion may use claim 1 independently.
Claim 6 and 8: film coating architecture
- Claim 6 includes selection among mono-layer, bi-layer, press-coated, or “drug-loading” film-coated tablet.
- Claim 8 specifies mono-layer tablet.
These are not the core chemical barriers but can matter in generic development and in how courts assess literal vs. non-literal infringement.
Claim 7: film coat components
Claim 7 requires film-coating agent and plasticizer, with optional glidant/pigments.
A generic that changes coating chemistry might attempt to argue non-literal infringement depending on whether it still falls within “film-coating agent” and “plasticizer” categories.
How are metformin dosing and tablet content tied together in claim 2?
Claim 2 adds a dosage-strength axis:
- metformin present about 100–1500 mg, and/or
- strength embodiments: 250, 500, 625, 750, 850, 1000 mg, and/or
- specific strengths subset: 500, 850, 1000 mg.
Because claim 1 already controls the metformin % by weight in the tablet, the combination product’s strengths are likely engineered so that the tablet ratio falls in-range for those strengths. That tight coupling raises the practical difficulty of “moving” to adjacent dose sizes without falling into composition ratio constraints.
What patents are likely adjacent to 10,973,827 in the US estate for similar combos (and what scope they typically cover)?
Based strictly on the claim structure, the US estate around 10,973,827 typically clusters into three technical layers:
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API substance and stereochemistry patents
- Cover synthesis and stereochem-specific preparation of the xanthine scaffold with (R)-configuration.
- Such patents govern whether a competitor can lawfully make or use the exact xanthine API, separate from formulation patents.
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Combination composition patents
- Metered combination of the xanthine with metformin and an amino acid stabilizer.
- 10,973,827 fits here: the inclusion of a basic amino acid to suppress degradation is a formulation/stability concept.
- Nearby patents may cover different stabilizers, concentration ranges, or alternative tablet forms (immediate vs extended release).
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Tablet formulation and coating patents
- Excipient ranges, binder/filler/lubricant/glidant selection, film coat composition, and performance specifications.
- 10,973,827 contains a relatively dense set of such constraints (claims 5, 7, 9, 10).
Without the patent’s publication number, assignee, priority chain, and prosecution record, a full cross-patent mapping (US family members; continuations; related WO/EP/JP grants; Orange Book entries) cannot be produced from the claim text alone.
How does US Patent 10,973,827 affect generic or Paragraph IV risk for a film-coated metformin + xanthine + L-arginine tablet?
For a generic to avoid literal claim 1, it must break at least one of the claim’s mandatory anchors:
- Use a different xanthine entity (different substitution pattern or stereochemistry), or
- Use metformin outside the 47–85% by weight envelope (and/or outside dosage strength embodiments of claim 2), or
- Avoid a basic amino acid that is an intramolecular amino basic amino acid with alkaline characteristics and does the functional “suppress degradation” role, or
- Avoid the required L-arginine mg range and/or the xanthine:L-arginine weight ratio range in dependent claims, or
- Use excipient quantities outside the ranges in claim 1, or
- Change the tablet to no longer be a film-coated tablet as claimed (or change the film coat so it is not “film-coated” in the claim sense), or
- Fail the immediate release dissolution requirement and/or mechanical/performance metrics if the asserted claims include claims 9 or 10.
If an ANDA uses the same actives and tablet architecture but differs in excipient identities, claim 1 may still catch it if excipient percentages fall within required ranges. If it differs mainly in dissolution profile or tablet performance, the patent becomes more test-data dependent under claim 9/10.
What is the practical enforcement posture suggested by the claim dependency structure?
A typical infringement strategy for a formulation patent like 10,973,827 is:
- Plead claim 1 (composition + film-coated tablet + excipient ranges + metformin/xanthine/basic amino acid + suppression function).
- Add claim 2/3/4 to fix dosing and stabilizer amounts.
- Add claim 5 for excipient identity, claim 6/8 for mono-/multi-layer, and claim 9/10 for dissolution and tablet mechanics.
That provides multiple independent claim “entry points” into the accused product.
What FDA regulatory entry risks exist for the exact claim-covered product?
The claim text implies an ANDA-relevant situation: a metformin-containing immediate release film-coated combination with excipient and dissolution targets.
However, a complete Orange Book and FDA status analysis cannot be produced from claim text alone because it requires:
- the listed drug product name(s) and NDA/ANDA numbers,
- Orange Book patent listing mapping to patent numbers (including 10,973,827),
- any exclusivity periods and Orange Book expiry dates,
- related FDA dissolution/biowaiver or bridging decisions.
Key Takeaways
- US Patent 10,973,827 is a film-coated tablet composition patent that tightly defines: a specific (R)-stereospecific xanthine, metformin HCl at defined weight fractions and dose strengths, and L-arginine as a stabilizing basic amino acid at specified mg ranges and xanthine:L-arginine ratios.
- The claim set escalates from broad ranges (claim 1) to near “spec-sheet” constraints (claim 10) covering core composition plus tablet mechanical and dissolution/performance metrics.
- For generic design-around, the most meaningful literal “break points” are: changing the xanthine identity/stereochemistry, moving metformin content/dose strength outside claim 1/2, removing/altering L-arginine in ways that fail mg and ratio ranges, and failing the dissolution (claim 9) or mechanical/disintegration envelope (claim 10) when those claims are asserted.
- A complete US patent landscape view (related family members, Orange Book listing, litigation/ANDA filings, settlement outcomes, expiration-by-jurisdiction) cannot be generated from the claim text alone.
FAQs
- What does “basic amino acid having an intramolecular amino group and alkaline characteristics” practically require—only L-arginine or any basic amino acid that stabilizes the xanthine?
- Can a generic avoid claim 10 by changing tablet disintegration time without changing the core percentages?
- If metformin strength is changed to an unlisted dose (outside claim 2), can the product still infringe claim 1 due to the metformin % by weight constraint?
- How do excipient identity changes (different filler/binder) interact with claim 1’s excipient percentage ranges?
- In litigation, how do courts typically treat claim 9 dissolution thresholds when the accused product shows variability across lots?
References
- US Patent 10,973,827 (claims as provided in the prompt).
