US Patent 12,257,218: Scope, Claim Architecture, and US Patent Landscape
US 12,257,218 claims a specific bilayer tablet formulation that combines guaifenesin, dextromethorphan, and naproxen with a 12-hour therapeutic effect, where naproxen rapidly dissolves under pH 6.8 phosphate buffer conditions and where the immediate release layer is defined by what it does not contain (no hypromellose, no hydroxyethyl cellulose). Claims 2-4 and 5-8 tighten the formulation by specifying surfactant (sodium lauryl sulfate) and base (sodium bicarbonate) localization and amounts.
What the claims protect (scope in one line)
A bilayer immediate-release + controlled-release (by absence of certain excipients in the immediate layer) tablet with quantified drug loads (guaifenesin, dextromethorphan, naproxen) and windowed polymer contents (hypromellose, hydroxyethyl cellulose), plus an optional surfactant/base module with localized inclusion in the immediate release layer, engineered to meet two performance constraints: 12-hour therapeutic effect and substantially all naproxen dissolves within 30 minutes at pH 6.8.
How is the claim scope structured? (independent vs dependent)
Independent claim 1
Claim 1 sets the core combination and performance requirements and defines the bilayer tablet’s excipient placement.
Core composition elements
- Guaifenesin: about 600 mg
- Dextromethorphan: about 30 mg (or pharmaceutically acceptable salt)
- Naproxen: about 110 mg (or pharmaceutically acceptable salt)
- Hypromellose: 18 to 28 mg
- Hydroxyethyl cellulose: 8 to 14 mg
Performance constraints
- Provides therapeutic effect for 12 hours for each of:
- guaifenesin
- naproxen
- dextromethorphan
- Naproxen dissolution requirement:
- Substantially all naproxen dissolves within 30 minutes
- in pH 6.8 phosphate buffer
Bilayer/tablet and layer-content constraints
- Pharmaceutical composition is a bilayer tablet
- Immediate release layer contains:
- Substantially all of the naproxen
- At least about 100 mg guaifenesin
- At least about 8 mg dextromethorphan
- Immediate release layer exclusions:
- contains none of the hypromellose
- contains none of the hydroxyethyl cellulose
Practical reading of scope
- The patent draws a bright line: if hypromellose or hydroxyethyl cellulose appears in the immediate release layer, claim 1 is not met.
- If naproxen is not largely in the immediate release layer, claim 1 is not met.
- The formulation must meet both the dissolution performance metric and the 12-hour therapeutic-effect profile.
Dependent claims 2-4
These claims add a defined surfactant and base.
- Claim 2 adds:
- 0.1% to 2% sodium lauryl sulfate (SLS) by weight of total composition
- 1% to 10% sodium bicarbonate (NaHCO3) by weight of total composition
- Claim 3 narrows to specific masses:
- SLS: about 10-11 mg
- NaHCO3: about 30-60 mg
- Claim 4 localizes these additives:
- Immediate release layer contains:
- substantially all of the SLS
- substantially all of the NaHCO3
Practical reading of scope
- If SLS and/or NaHCO3 are split into the other layer, claim 4 is avoided.
- If SLS and NaHCO3 amounts fall outside the windows, claim 2 or 3 is avoided.
Independent claim 5
Claim 5 re-states the core bilayer and performance requirements and adds fixed inclusion of SLS and NaHCO3, then builds to polymer-dependent variants in claims 6-8.
Claim 5 differs from claim 1 by defining:
- SLS: about 10-11 mg
- NaHCO3: about 30-60 mg
and requires the same performance and bilayer constraints.
Dependent claims 6-8
- Claim 6 adds polymer content windows by weight of total composition:
- 1-8% hypromellose
- 1-2% hydroxyethyl cellulose
- Claim 7 fixes the masses:
- hypromellose: about 18-28 mg
- hydroxyethyl cellulose: about 8-14 mg
- Claim 8 repeats the key excipient exclusion in the immediate layer:
- immediate release layer contains none of hypromellose
- immediate release layer contains none of hydroxyethyl cellulose
What does “substantially all” and the dissolution condition practically do to scope?
The claims tie infringement risk to two testable conditions:
1) Naproxen dissolution test gate
- Condition: pH 6.8 phosphate buffer
- Criterion: substantially all naproxen dissolves within 30 minutes
Scope impact
- A design-around that slows dissolution beyond 30 minutes in that medium can avoid the claim even if the drug loads match.
- A design-around that transfers naproxen out of the immediate-release layer also avoids the claim regardless of dissolution.
2) 12-hour therapeutic effect requirement
- Therapeutic effect for 12 hours for guaifenesin, naproxen, and dextromethorphan
Scope impact
- A formulation that meets naproxen dissolution but cannot sustain the other actives for 12 hours can avoid the claim.
- A formulation that meets the polymer mass windows but shifts release kinetics outside 12 hours also risks avoidance.
Layer-content constraints: where design-arounds most often succeed
The claims include explicit exclusions that function like “infringement tripwires.”
Immediate release layer exclusions (high value limitation)
- For claims 1 and 8:
- Immediate release layer contains none of hypromellose
- Immediate release layer contains none of hydroxyethyl cellulose
Scope impact
- Using those polymers in the immediate layer can avoid literal infringement even if all other constraints are met.
- Conversely, removing those polymers from the immediate layer and placing them in the other layer increases literal coverage.
Immediate release layer required inclusions
- Claim 1 and 5 require immediate layer to contain:
- substantially all naproxen
- at least 100 mg guaifenesin
- at least 8 mg dextromethorphan
Scope impact
- A formulation that retains naproxen in the second layer or substantially reduces naproxen in the immediate layer avoids literal infringement.
- A formulation that distributes guaifenesin and/or dextromethorphan such that less than the stated minimums are in the immediate layer also avoids.
SLS and bicarbonate localization (in claims 4 and 5-dependent structure)
- Claim 4: immediate release layer has substantially all SLS and NaHCO3
- Claim 5: immediate release layer must include these amounts within the bilayer construct
Scope impact
- Splitting SLS or NaHCO3 into the second layer avoids claim 4’s localization requirement.
Claim-by-claim infringement “checklist” (literal requirements)
Claim 1 literal checklist
A product must be a bilayer tablet with:
- 600 mg guaifenesin
- 30 mg dextromethorphan (or salt)
- 110 mg naproxen (or salt)
- 18-28 mg hypromellose and 8-14 mg hydroxyethyl cellulose in the composition
- 12-hour therapeutic effect for guaifenesin, naproxen, and dextromethorphan
- Naproxen dissolves within 30 minutes in pH 6.8 phosphate buffer
- Immediate release layer contains substantially all naproxen, plus minimums of guaifenesin and dextromethorphan
- Immediate release layer contains none of hypromellose and hydroxyethyl cellulose
Claim 2 and 3 literal checklist
In addition to claim 1:
- SLS: 0.1% to 2% by weight (claim 2), and/or 10-11 mg (claim 3)
- NaHCO3: 1% to 10% by weight (claim 2), and/or 30-60 mg (claim 3)
Claim 4 literal checklist
In addition to claim 2-3:
- Immediate release layer contains substantially all of SLS and NaHCO3
Claim 5 literal checklist
A product must be a bilayer tablet with:
- 600 mg guaifenesin
- 30 mg dextromethorphan
- 110 mg naproxen
- 10-11 mg SLS
- 30-60 mg NaHCO3
- 12-hour therapeutic effect for all three actives
- Naproxen dissolves within 30 minutes in pH 6.8 phosphate buffer
- Immediate release layer contains substantially all naproxen plus minimums of guaifenesin and dextromethorphan
- Immediate release layer contains substantially all SLS and NaHCO3
Claims 6-8 literal checklist
- Claim 6 adds weight % windows for hypromellose and hydroxyethyl cellulose
- Claim 7 locks them to mass windows (18-28 mg; 8-14 mg)
- Claim 8 repeats immediate layer polymer exclusions
Where this sits in the US patent landscape (what can and cannot be concluded from the information provided)
This request requires an authoritative US patent landscape analysis for US 12,257,218 (e.g., related families, cited art, continuations, reexaminations, and competitors’ likely design-arounds), which depends on the published patent document record (title, assignee, publication number, application data, prosecution history, and the patent’s cited references). The claim text alone is not sufficient to produce a complete and accurate US landscape mapping.
Under the constraints here, a complete landscape analysis cannot be reliably produced without access to the patent record and citation set for US 12,257,218.
Key Takeaways
- US 12,257,218 is a bilayer tablet formulation patent with quantified drug loads and two performance gates: 12-hour therapeutic effect for all three actives and rapid naproxen dissolution within 30 minutes in pH 6.8 phosphate buffer.
- The strongest claim limitation is layer excipient placement: the immediate release layer must contain none of hypromellose and hydroxyethyl cellulose (claims 1 and 8).
- Claims 2-4 and 5-4 variants add SLS and sodium bicarbonate with amount limits and, for claim 4, localization to the immediate layer.
- For design-around, the most direct literal-avoidance levers are:
- move hypromellose/hydroxyethyl cellulose into the immediate layer,
- reduce naproxen presence in the immediate layer,
- shift SLS/NaHCO3 out of the immediate layer (for the dependent localization claim),
- fail either the dissolution window or the 12-hour therapeutic window.
FAQs
1) What is the bilayer functional requirement in the claims?
It is the combination of (i) immediate layer containing substantially all naproxen and minimum guaifenesin/dextromethorphan, (ii) immediate layer containing none of hypromellose and hydroxyethyl cellulose, and (iii) meeting 12-hour therapeutic effect plus rapid naproxen dissolution.
2) Does the patent require naproxen to dissolve quickly even though it is in a bilayer tablet?
Yes. The claims require substantially all naproxen dissolves within 30 minutes in pH 6.8 phosphate buffer.
3) Are hypromellose and hydroxyethyl cellulose optional?
No. Claim 1 requires them in specified mass ranges (18-28 mg and 8-14 mg). Claims 6-7 and 8 further constrain the amounts and immediate-layer exclusion.
4) What do claims 2-4 add beyond claim 1?
They add sodium lauryl sulfate and sodium bicarbonate with defined weight ranges (claims 2-3) and require substantially all of them be in the immediate release layer (claim 4).
5) How can a competitor most easily avoid literal infringement?
By violating the immediate layer exclusions (put hypromellose/hydroxyethyl cellulose in the immediate layer) or the dissolution/therapeutic time gates, or by failing the immediate layer composition minimums and/or localization for naproxen and, where applicable, SLS/NaHCO3.
References
[1] User-provided claim text for US 12,257,218 (claims 1-8).
