US Patent 7,018,656: Scope, Claim Boundaries, and US Landscape for 1-Hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone Gels
What does US 7,018,656 actually claim?
US Patent 7,018,656 claims gel compositions that combine (i) a specific active ingredient class based on 1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone (and its physiologically tolerable salts) with (ii) a polyacrylic acid polymer gel matrix and (iii) a specific pair of excipients selected from two separate formulation “sets,” under a key structural limitation: the gel is not an emulsion.
The two independent claims you provided are composition claims with the same core active and polymer, but different excipient packages.
What is the independent-claim scope of claim 1 vs claim 2?
Claim 1 scope (excipient set A)
Claim 1 requires all of the following in one gel composition:
- Active: at least one compound chosen from
1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone and physiologically tolerable salts thereof
- Gelling agent: polyacrylic acid polymer
- Surfactant/wetting agent: sodium dioctylsulfosuccinate
- Emollient/co-surfactant: 2-octyldodecanol
- Structural limitation: the composition is not an emulsion
Claim 2 scope (excipient set B)
Claim 2 requires all of the following in one gel composition:
- Active: at least one compound chosen from
1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone and physiologically tolerable salts thereof
- Gelling agent: polyacrylic acid polymer
- Surfactant/emulsifier family member: polyoxyethylene(20)sorbitan monostearate
- Emollient/co-surfactant: isopropyl myristate
- Structural limitation: the composition is not an emulsion
Structural take: excipient set control the practical scope
The claims are not limited to route of administration or therapeutic indication in what you provided. Scope in practice turns on four elements:
- The active identity (and salts) is fixed to the claimed pyridone scaffold.
- The gel matrix is fixed to polyacrylic acid polymer.
- Only one of two excipient packages is required (Claim 1 or Claim 2), but each is all-or-nothing.
- The “not an emulsion” limitation is the gating factor that differentiates from classic emulsion gels or microemulsions.
How do the “not an emulsion” limitation and the excipient choices affect infringement risk?
The claims combine:
- polyacrylic acid polymer (typical gelling polymer)
- lipophilic ingredients (2-octyldodecanol in Claim 1; isopropyl myristate in Claim 2)
- surface-active ingredients (sodium dioctylsulfosuccinate in Claim 1; polyoxyethylene(20)sorbitan monostearate in Claim 2)
Those ingredient combinations can produce formulations that are either:
- true polymer gels (continuous phase is largely aqueous, polymer-dominated microstructure), or
- emulsion-type systems (dispersed oil droplets, surfactant stabilizes droplets), including emulsion gels and some microemulsion-like structures.
Practical implication for enforcement and design-around:
To fall inside the claim, an accused gel must satisfy all composition elements and also avoid being an emulsion as construed under patent practice (typically by structural characterization, phase behavior, and whether oil is dispersed in droplets stabilized by surfactants).
What claim language is doing the narrowing?
1) Active definition is closed to a known scaffold
“at least one compound chosen from 1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone and physiologically tolerable salts thereof” is a tight definition. Unless a competitor uses that scaffold (or a physiologically tolerable salt form), it cannot enter the independent claim.
2) Polymer identity is locked
“polyacrylic acid polymer” narrows the gelling agent universe. If a formulation uses a different polymer (e.g., carbomers crosslinked acrylic acid derivatives, HPMC, PVP, CMC), it may not meet this element depending on claim construction. If “polyacrylic acid polymer” is construed broadly enough to include carbomer-type materials, the risk rises; if construed narrowly, risk drops.
3) Excipient package is fixed
Claim 1’s combination is specific to sodium dioctylsulfosuccinate plus 2-octyldodecanol.
Claim 2’s combination is specific to polyoxyethylene(20)sorbitan monostearate plus isopropyl myristate.
A competitor that swaps either the surfactant or the oil-phase ingredient may avoid an element, depending on whether the replaced excipient is literally recited or captured by dependent-claim substitutions (none provided) or doctrine-of-equivalents theory.
4) “Not an emulsion” is a structural/functional limitation
This is the single most “litigation-active” phrase in your excerpt. It is likely to drive disputes on:
- whether the dispersed phase exists,
- droplet size distribution and morphology,
- whether the formulation behaves as an emulsion under characterization methods.
Where does the patent sit in the US landscape for these actives and gel excipients?
Based on the claim formulation, US 7,018,656 targets a specific approach to topical or semi-solid delivery using:
- a particular pyridone active,
- a polyacrylic acid polymer gel base,
- and two alternative excipient pairs that stabilize delivery without forming an emulsion.
Landscape interpretation (business-relevant)
In enforcement and freedom-to-operate (FTO) terms, the patent is best viewed as a formulation envelope defined by:
- active scaffold identity,
- polymer identity,
- a two-option excipient pair,
- and a non-emulsion constraint.
This usually implies the competitive field includes three categories of products:
- Literal copy risk (high): same active + same polymer + one of the excipient sets + non-emulsion characterization.
- Element-swap risk (medium): same active + same polymer, but different surfactant/emollient or different oil component; risk depends on claim interpretation and equivalence.
- Matrix swap risk (medium to low): different gel polymer (even if same active and excipients) reduces the chance of literal infringement.
Because your excerpt is limited to two independent claims, the full landscape will depend on whether the specification discloses additional embodiments and whether dependent claims expand coverage to alternate surfactants, oils, salt forms, or polymer variants. That information is not present in what you provided, so only the boundaries implied by claims 1 and 2 can be mapped here.
What design-arounds are structurally suggested by the claim elements?
These are not recommendations; they are the logical “escape hatches” implied by the claim’s element-by-element limitations.
Avoiding the independent-claim elements
To exit Claim 1 coverage, an accused gel would need to fail at least one of:
- not use the claimed pyridone active/salt,
- not use polyacrylic acid polymer,
- not include sodium dioctylsulfosuccinate, or
- not include 2-octyldodecanol, or
- be characterized as an emulsion.
To exit Claim 2 coverage, an accused gel would need to fail at least one of:
- not use the claimed pyridone active/salt,
- not use polyacrylic acid polymer,
- not include polyoxyethylene(20)sorbitan monostearate, or
- not include isopropyl myristate, or
- be characterized as an emulsion.
Emulsion characterization is a litigation lever
Because both claims include the same “not an emulsion” limitation, a formulation that is demonstrably an emulsion (if other elements are met) may fall outside the claims even if excipients match. Conversely, if an accused product is an emulsion but can be argued otherwise, the dispute is likely to focus on expert characterization evidence.
How to read the claims for scope breadth in licensing and competitive planning
Core scope summary table
| Claim |
Active |
Gel polymer |
Surfactant |
Lipophilic ingredient |
Emulsion limitation |
| 1 |
1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone (or physiologically tolerable salt) |
polyacrylic acid polymer |
sodium dioctylsulfosuccinate |
2-octyldodecanol |
“not an emulsion” |
| 2 |
1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone (or physiologically tolerable salt) |
polyacrylic acid polymer |
polyoxyethylene(20)sorbitan monostearate |
isopropyl myristate |
“not an emulsion” |
What the patent does not claim (based on the excerpt)
From what you provided, the claims do not explicitly recite:
- a concentration range,
- a pH range,
- a specific indication,
- manufacturing steps,
- particle size,
- viscosity specifications,
- or specific delivery/permeation claims.
This makes the scope more “composition-wide” but also more dependent on interpretation of the polymer and emulsion boundaries.
Patent landscape mapping logic for US prosecutions and continued family filings
Without bibliographic data beyond the patent number, the only defensible landscape mapping here is methodological: in this kind of formulation patent, later US continuations (if any) typically attempt to capture:
- alternate excipient pairs (different surfactant and oil),
- alternate polymer variants (within “polyacrylic acid polymer” scope),
- alternate salt forms,
- and sometimes viscosity/pH-controlled embodiments.
If later patents exist in the same family, they will often broaden away from the exact two excipient sets while keeping the active scaffold and non-emulsion framing, or shift the “not an emulsion” language to a different structural definition (e.g., “no dispersed oil phase”) depending on prosecution history.
Since no additional patent numbers, family members, or citations were provided, the landscape here is confined to what can be concluded from the claim text itself.
Key Takeaways
- US 7,018,656 is a formulation-enforced composition patent: it claims gels that contain the specified pyridone active scaffold, polyacrylic acid polymer, and one of two fixed excipient pairs.
- Claim 1 and Claim 2 differ only by excipient package, not by active or polymer. Claim 1 uses sodium dioctylsulfosuccinate + 2-octyldodecanol; Claim 2 uses polyoxyethylene(20)sorbitan monostearate + isopropyl myristate.
- The gating limitation in both claims is “wherein the composition is not an emulsion,” making emulsion characterization a central dispute point for infringement analyses.
- For competitive planning and licensing, the risk concentrates on products that match: active + polyacrylic acid gel + one excipient pair + non-emulsion structure.
FAQs
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Does US 7,018,656 cover any gel with 1-hydroxy-4-methyl-6-cyclohexyl-2(1H)pyridone?
No. The claims additionally require polyacrylic acid polymer, one of the two specified excipient pair sets, and that the gel is not an emulsion.
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If a product uses the same excipients but forms an emulsion, does it infringe?
The claims include an explicit “not an emulsion” limitation, so emulsion characterization is a direct boundary for infringement.
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Can a formulation avoid infringement by changing only the oil ingredient?
It can avoid the literal element requirement if it omits the exact recited oil (2-octyldodecanol for Claim 1; isopropyl myristate for Claim 2), subject to claim construction and equivalence analysis.
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What excipient change poses the highest risk to design-around?
Substituting excipients while maintaining all other elements can still create infringement exposure if claim construction treats the substituted component as satisfying the recited element, but the safest structural path implied by the claims is to break at least one required element.
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Are concentration ranges or therapeutic uses part of the scope based on the provided claims?
Not from the excerpted claim text you provided. The independent claims as shown are composition-element based.
References
[1] US Patent 7,018,656 (claim text provided by user).
