US Patent 12,071,423 landscape: how broad are the formulation claims for an immediate-release tablet and what design-arounds matter
US Patent 12,071,423 is a US formulation patent focused on an immediate-release (IR) tablet containing a specific API salt plus defined ranges for common excipients (microcrystalline cellulose, pregelatinized starch, sodium lauryl sulfate, croscarmellose sodium, magnesium stearate) and a defined amount of a film coating. The enforceable scope is driven by (i) the active ingredient identity and salt form (2,4,6-trifluoro-N-[6-(1-methyl-piperidine-4-carbonyl)-pyridin-2-yl]-benzamide hemisuccinate, quantified as free base equivalent), (ii) the IR tablet attribute, and (iii) whether an accused product’s excipient levels fall inside the numerical ranges recited in independent claim 1 and the narrower dependent compositions in claims 2 and 3.
What is US Patent 12,071,423 and what do its claims actually cover?
Short answer: The patent claims a specific IR tablet composition defined by an API hemisuccinate salt (with dose expressed as free-base equivalent) and a fixed formulation architecture using selected excipients at claimed quantities, plus film coating amount, and optionally a unit-dose blister packaging format.
Claim-set structure and claim dependence
- Claim 1 (independent): IR tablet with:
- (a) API: 50 to 100 mg free base equivalent of the stated compound as hemisuccinate
- (b) microcrystalline cellulose: 30.86 to 61.71 mg
- (c) pregelatinized starch: 7.5 to 15.00 mg
- (d) sodium lauryl sulfate: 0.56 to 1.12 mg
- (e) croscarmellose sodium: 5.63 to 40.53 mg
- (f) magnesium stearate: 2.25 to 4.50 mg
- (g) film coating: 3.519 to 7.035 mg
- Claims 2 and 3 (dependent, but written as complete compositions):
- Claim 2 fixes each component at one set of endpoints (50 mg API free base equivalent; mid-range excipient amounts including croscarmellose sodium at 13.51 mg and film coating at 3.519 mg).
- Claim 3 fixes each component at the high endpoints (100 mg API free base equivalent; higher croscarmellose sodium at 40.53 mg and film coating at 7.035 mg).
- Claim 4 (dependent): The tablet of claim 1 in a unit-dose blister.
Key enforceability levers
- API identity and salt form is a hard gate.
- Immediate-release is a functional/attribute limitation.
- Numerical ranges for excipient quantities create direct infringement and design-around risk boundaries.
- Film coating amount is a further numeric limitation.
- Blister packaging (claim 4) adds a packaging format limitation that is often harder to reach unless the accused product’s packaging matches.
How broad are claim 1’s ranges for an immediate-release tablet (and where do infringement boundaries sit)?
Short answer: Claim 1 is moderately broad in the API dose (50–100 mg) and excipient range sizes are mixed: microcrystalline cellulose and pregelatinized starch are tight relative to many excipient formulations, while croscarmellose sodium has a very wide range. This drives both the center-of-mass infringement risk and potential partial design-arounds.
Range width and practical impact
Below are the claim-1 endpoints you provided, interpreted as quantity per unit tablet:
| Component (claim 1) |
Claimed range (mg) |
Breadth signal |
Infringement boundary risk |
| API hemisuccinate, expressed as free base equivalent |
50 to 100 mg |
Medium |
High if API salt form matches |
| Microcrystalline cellulose |
30.86 to 61.71 |
Medium-narrow |
If target is 32–60 mg, easy to fall inside |
| Pregelatinized starch |
7.5 to 15.0 |
Medium-narrow |
Similar practical risk to MCC |
| Sodium lauryl sulfate |
0.56 to 1.12 |
Narrow |
Small formulation changes may avoid |
| Croscarmellose sodium |
5.63 to 40.53 |
Very wide |
Many market formulations may overlap |
| Magnesium stearate |
2.25 to 4.50 |
Medium-narrow |
Some room to move |
| Film coating |
3.519 to 7.035 |
Narrow |
Coating weight often tightly controlled; design-around possible but requires manufacturing shift |
“Center-of-claim” zones vs edge zones
- If an accused IR tablet’s excipients are formulated around typical mid-range values, infringement is likely.
- Avoidance by moving outside the ranges depends on how easily the formulation can be reformulated without changing dissolution/IR performance and without switching excipients to different functional equivalents.
How do claims 2 and 3 narrow infringement to fixed compositions?
Short answer: Claims 2 and 3 are essentially fixed-point embodiments. If a competitor lands on one of those endpoint compositions, it is closer to clean “all-elements” match.
Claim 2 fixed composition (50 mg free base equivalent)
- API: 50 mg
- MCC: 30.86 mg
- Pregelatinized starch: 7.5 mg
- Sodium lauryl sulfate: 0.56 mg
- Croscarmellose sodium: 13.51 mg
- Magnesium stearate: 2.25 mg
- Film coating: 3.519 mg
Claim 3 fixed composition (100 mg free base equivalent)
- API: 100 mg
- MCC: 61.71 mg
- Pregelatinized starch: 15.00 mg
- Sodium lauryl sulfate: 1.12 mg
- Croscarmellose sodium: 40.53 mg
- Magnesium stearate: 4.50 mg
- Film coating: 7.035 mg
Litigation relevance
- In disputes, fixed compositions can become “anchor points” for expert testimony:
- If accused product COA (certificate of analysis) shows all values align with claim 2 or 3, infringement exposure rises.
- If accused values sit within claim 1 ranges but not claim 2 or 3 endpoints, claim 1 still provides coverage.
What does claim 4 add: does unit-dose blister packaging change patent scope?
Short answer: Claim 4 narrows claim 1 by requiring the accused IR tablet to be provided in a unit-dose blister. Packaging limitations can materially reduce enforcement reach versus composition-only claims, because the infringing act depends on packaging configuration in commerce.
Practical enforcement effect
- If the competitor sells the same IR tablet in bottles, strips without blisters, or bulk formats that do not meet “unit-dose blister,” claim 4 may not apply even if claim 1 does.
- Claim 4 is usually a secondary hook unless the competitor uses the same packaging strategy.
What key claim-construction disputes are likely for an immediate-release tablet formulation?
Short answer: The most likely construction issues are (i) “immediate-release” definition, (ii) the basis for “free base equivalent” calculation for a hemisuccinate salt, and (iii) whether excipient “amounts” are interpreted as per-tablet finished weight inclusive/exclusive of specific subcomponents (especially film coating).
Immediate-release attribute
- An “immediate-release” limitation is often litigated via dissolution testing frameworks and specification language from the patent or regulatory filings.
- Even if excipient ranges match, a competitor could argue that its dissolution profile is outside the patent’s implied IR definition.
Free base equivalent vs salt mg
- The claims quantify the hemisuccinate using “free base equivalent.” In practice, infringement turns on:
- the conversion factor used for hemisuccinate-to-free-base calculations, and
- whether the accused formulation labels/COAs can be reconciled to that conversion.
Film coating amount
- “Film coating” mg is a numeric limitation that can be attacked with measurement methodology and definitions (e.g., whether certain coating layers or colorants count).
- This is a high-value design-around lever if feasible without altering dissolution.
How strong is the patent estate for formulation protection: what is actually protected here?
Short answer: On the information provided (claims only), US 12,071,423 is strong as a composition-of-matter-in-practice formulation claim, but its scope is not “platform broad” across other salts, other release profiles (ER/CR), or tablets with substantially different excipient choices or quantities.
Scope boundaries created by the claims you supplied
- Covered:
- IR tablets
- containing the specific hemisuccinate salt of the specified compound
- with excipient identities exactly as listed (MCC, pregelatinized starch, sodium lauryl sulfate, croscarmellose sodium, magnesium stearate) at amounts within ranges
- with a film coating in the recited mg range
- Not covered by these claim texts alone:
- other salts (different counterions) of the same API
- IR tablets using substitute superdisintegrants instead of croscarmellose sodium
- IR tablets with different excipient types not named
- ER/CR formulations, even if composition matches
- tablets where film coating mg falls outside the range
- packaging formats outside “unit-dose blister” for claim 4
What design-around routes exist for a generic or branded competitor facing these claims?
Short answer: The clearest design-arounds come from (i) changing salt form, (ii) moving outside excipient quantity ranges, and (iii) shifting film coating amount, provided the changes maintain IR performance and regulatory equivalence.
1) Salt switch (highest-leverage)
- Replace the hemisuccinate with another acceptable salt form to avoid the hard “hemisuccinate” identity requirement.
- This is a typical formulation patent avoidance route but may carry bioavailability and development risk.
2) Excipient quantity shifts (range evasion)
- Because claim 1 uses numeric ranges, a competitor can target:
- sodium lauryl sulfate below 0.56 mg or above 1.12 mg
- film coating below 3.519 mg or above 7.035 mg
- magnesium stearate below 2.25 mg or above 4.50 mg
- These are numerically narrow and thus more actionable than the wide croscarmellose sodium range.
3) Film-coating engineering (often a manageable lever)
- Changing coating level to fall outside 3.519–7.035 mg can avoid the film coating limitation while keeping core tablet composition within other ranges.
- Manufacturing and dissolution effects must remain consistent with the label and bioequivalence objectives.
4) Croscarmellose sodium manipulation (less reliable)
- The wide 5.63–40.53 mg range means many formulations will still infringe claim 1 if they use croscarmellose sodium within that broad window.
- Outside-range shifts may impact disintegration and dissolution.
5) Packaging (only for claim 4)
- Selling the same composition without a unit-dose blister format can avoid claim 4, but not claim 1.
How does this formulation patent interact with FDA generic pathways (ANDA) and Paragraph IV risk?
Short answer: If an ANDA applicant submits an IR tablet using the same API salt form and a formulation that falls within claim 1’s excipient quantities and film coating range, the product is at elevated risk for a Paragraph IV challenge/filing-filing infringement dispute tied to US 12,071,423. If the applicant uses a different salt form or a formulation outside the claimed quantities, the infringement risk drops.
Claim-driven ANDA risk map
- High risk:
- same hemisuccinate salt
- IR profile
- matching excipient identities and values within ranges
- film coating in the claimed mg window
- Medium risk:
- same hemisuccinate salt and IR
- excipient values are near edge of one or more ranges, creating construction and measurement disputes
- Lower risk:
- different salt form
- different excipient types
- different release profile
- film coating outside claimed mg range
(No Orange Book listings, FDA approval history, or Paragraph IV filings were provided in the input. The analysis above is claim-text-driven.)
What patent expiration timing matters for this formulation: when would generic entry become possible?
Short answer: Timing cannot be determined from claim text alone. Patent expiration depends on:
- the application and grant dates,
- any terminal disclaimers,
- nonprovisional filing date,
- maintenance status,
- and whether any formulation-only claims are later limited or invalidated.
No filing/priority/maintenance data was provided for US 12,071,423, so expiration and exclusivity windows cannot be stated accurately.
Key takeaways
- US 12,071,423 is an immediate-release tablet formulation patent with a hard lock on the API being 2,4,6-trifluoro-N-[6-(1-methyl-piperidine-4-carbonyl)-pyridin-2-yl]-benzamide hemisuccinate, quantified by free base equivalent.
- Claim 1’s infringement footprint is defined by tight numeric ranges for excipients and film coating mg, with a notably wide range for croscarmellose sodium.
- Claims 2 and 3 are fixed-point embodiments (50 mg and 100 mg endpoints) that can simplify “all-elements” match in enforcement.
- Claim 4 adds a unit-dose blister packaging limitation, which can reduce enforcement reach versus composition-only exposure.
- The most direct design-arounds are salt switching, moving key excipient quantities and/or film coating mg outside the recited windows, and changing packaging only for claim 4.
- Patent estate strength, Orange Book status, Paragraph IV litigation, and expiration timing cannot be concluded from the claim text alone.
FAQs
1) What excipient changes most reduce infringement risk under claim 1?
Moving sodium lauryl sulfate, magnesium stearate, and especially film coating amount outside their recited mg ranges is the most direct mathematical route because those ranges are narrow.
2) Does using the same API but a different salt avoid this patent?
Yes on the claim text provided, because claim 1 requires the API as the hemisuccinate salt.
3) If a generic matches excipient ranges but has a different release profile, is it covered?
Not under these claims as written, because claim 1 requires an immediate-release tablet.
4) Can a company avoid claim 4 without changing composition?
Yes, by changing the product packaging such that it is not “provided in a unit-dose blister,” while composition still risks claim 1.
5) Are claims 2 and 3 broader than claim 1?
No. They narrow to specific fixed embodiments corresponding to the endpoints, while claim 1 covers a broader range.
References
- Provided patent claim text for US Patent 12,071,423 (user input).
