US Patent 11,213,519: Scope, Claims, and U.S. Patent Landscape for Topical Triazole-Based Onychomycosis Treatment
What does US 11,213,519 claim, in practical scope terms?
US 11,213,519 is directed to a method of treating onychomycosis by topical application to the nail surface of a specific solution containing: ethanol, diisopropyl adipate, C12-15 alkyl lactate, cyclomethicone, and a “triazole antifungal agent.” The method requires application in an amount and for a time sufficient to ameliorate symptoms (i.e., clinical or functional improvement consistent with onychomycosis management).
The core invention is not a new antifungal scaffold by itself, but a specific topical formulation system (vehicle/penetration components) paired with a triazole antifungal in a solution format, with additional limitations around concentration ranges and exclusion of polymeric film formers.
Claim-set structure
- Claim 1: Broadest method scope in the independent claim family
- Claims 2 and 5: Narrow to a specific triazole antifungal identity (same compound appears in both)
- Claims 3 and 6: Exclude polymeric film forming compounds
- Claim 4: Adds quantitative composition constraints (ethanol ≥ 50% w/w; cyclomethicone < 25% w/w; diisopropyl adipate + C12-15 alkyl lactate total 15 to 50% w/w)
What are the claim elements and how are they constrained?
Claim 1 (independent): method scope
Method for treating onychomycosis by:
- Topical application to nail surface of an individual with onychomycosis
- Using a pharmaceutical composition
- Composition contains (all):
- Ethanol
- Diisopropyl adipate
- C12-15 alkyl lactate
- Cyclomethicone
- A triazole antifungal agent
- Composition is formulated as a solution (not a film-forming delivery system)
- Application is in an amount and for a time sufficient to ameliorate symptoms
Key scope levers
- “Solution” is explicit.
- “Triazole antifungal agent” is generic in Claim 1, but later claims lock to a specific member.
- The method claim is driven by vehicle + antifungal + nail-surface topical application.
Claim 2: specific triazole antifungal
Claim 2 narrows Claim 1 by requiring the triazole antifungal agent to be:
- (2R,3R)-2-(2,4-difluorophenyl)-3-(4-methylenepiperidine-1-yl)-1-(1H-1,2,4-triazole-1-yl)butane-2-ol
This is a defined active. It eliminates most other triazoles from infringement coverage if they are not identical to the specified compound.
Claim 3: excludes polymeric film forming compounds
Claim 3 narrows Claim 1 by requiring that the composition:
- does not comprise a polymeric film forming compound
This blocks formulations that rely on polymer film formation (common in nail lacquer strategies) unless the polymer is absent.
Claim 4: quantitative formulation limits
Claim 4 narrows Claim 1 (and by dependency, also sits within the Claim 1 vehicle architecture) with constraints:
- Ethanol: at least 50% w/w
- Cyclomethicone: less than 25% w/w
- Diisopropyl adipate + C12-15 alkyl lactate (combined): 15 to 50% w/w total
- Still requires a triazole antifungal agent and solution formulation.
This claim converts “composition contains ingredients X/Y/Z” into a range-constrained composition.
Claim 5: Claim 4 + specific triazole
Claim 5 applies:
- the specific triazole identity from Claim 2
- plus the quantitative vehicle constraints from Claim 4.
Claim 6: Claim 1 + excludes polymeric film forming compound
Claim 6 mirrors Claim 3’s exclusion but is dependent on Claim 1 rather than Claim 4.
How do the independent/dependent claims impact infringement analysis?
The patent’s infringement risk for a competing product typically breaks into two axes:
Axis A: formulation class (solution vs film-forming)
- If a competitor uses a polymeric film-forming component, it is pushed outside coverage of Claims 3 and 6.
- If the product is a solution-only nail delivery, it has a better alignment with the “solution” language of Claim 1.
Axis B: vehicle composition boundaries (especially Claim 4)
Even if a competitor uses the required actives and vehicle ingredients, Claim 4’s concentration constraints create a “safe harbor” for designs outside those numeric bands:
- Ethanol must be ≥ 50% w/w for Claim 4-style capture
- Cyclomethicone must be < 25% w/w
- Combined diisopropyl adipate + C12-15 alkyl lactate must be 15 to 50% w/w
A competitor can aim to:
- stay within Claim 1 vehicle ingredient list but adjust concentrations to escape Claim 4
- or adjust active identity to escape the “specific triazole” claims (Claims 2/5), while still potentially falling under Claim 1 if the active qualifies as a “triazole antifungal agent.”
What is the patent’s practical claim coverage: “read-by-read” matrix
Below is a compact mapping of what each claim requires.
| Claim |
Treatment type |
Site |
Dosage form |
Antifungal scope |
Vehicle constraints |
Film former excluded |
Concentration limits |
| 1 |
Method treating onychomycosis |
Nail surface |
Solution |
Any triazole antifungal agent |
Ethanol + diisopropyl adipate + C12-15 alkyl lactate + cyclomethicone |
Not required |
No numeric limits |
| 2 |
Same |
Same |
Same |
Specified triazole |
Same as Claim 1 |
Not required |
No numeric limits |
| 3 |
Same |
Same |
Same |
Any triazole antifungal agent |
Same as Claim 1 |
Yes (polymeric film former absent) |
No numeric limits |
| 4 |
Same |
Same |
Same |
Any triazole antifungal agent |
Same ingredients |
Not required |
Ethanol ≥ 50% w/w; cyclomethicone < 25% w/w; diisopropyl adipate + C12-15 alkyl lactate = 15 to 50% w/w |
| 5 |
Same |
Same |
Same |
Specified triazole |
Same ingredients |
Not required |
Applies Claim 4 limits |
| 6 |
Same |
Same |
Same |
Any triazole antifungal agent |
Same ingredients |
Yes (polymeric film former absent) |
No numeric limits |
What claim vulnerabilities and design-around paths follow from this structure?
Design-around with active identity
- Claims 2 and 5 require one specific triazole molecule. A different triazole antifungal would avoid capture of those claims.
- Claim 1 remains broader if the alternative active still qualifies as a “triazole antifungal agent.” So switching actives may only partially mitigate risk.
Design-around with film formers
- Claims 3 and 6 exclude polymeric film-forming compounds.
- A competitor can use a non-polymeric “tackifier” approach while avoiding a polymeric film former, but if the competitor uses a polymeric film former, those claims fall away.
Design-around with ethanol/cyclomethicone/ester totals
To evade Claim 4, adjust formulation so it fails at least one numeric limit:
- ethanol < 50% w/w
- cyclomethicone ≥ 25% w/w
- diisopropyl adipate + C12-15 alkyl lactate outside 15 to 50% w/w total
Design-around with “solution” requirement
If the competitor changes to a format that is not a “solution” (e.g., emulsion, suspension, gel, or film-lacquer system), Claim 1’s “formulated as a solution” limitation can be a line of attack.
How does this claim set position within the onychomycosis U.S. landscape?
Onychomycosis patents in the U.S. commonly cluster by:
- Active antifungal selection (azoles, allylamines, others)
- Vehicle engineering for nail penetration and residence time (solvents, permeation enhancers)
- Delivery format (solution vs lacquer vs film-former systems)
US 11,213,519 sits tightly in the nail-surface topical solution lane, with a vehicle palette that is solvent-heavy (ethanol), ester-based (diisopropyl adipate; C12-15 alkyl lactate), silicone component (cyclomethicone), and an azole antifungal.
Vehicle signature in the claim language
The unique combination constrained in Claim 1 is:
- Ethanol
- Diisopropyl adipate
- C12-15 alkyl lactate
- Cyclomethicone
- plus a triazole antifungal agent
This combination narrows the field versus patents that use:
- different penetration enhancers
- different solvent systems
- film-lacquer polymer systems
- non-triazole actives
What does the claim set imply for competitive freedom to operate (FTO) work?
An FTO review anchored on US 11,213,519 would typically focus on whether a competitor product:
- Uses a topical nail-surface regimen for onychomycosis that is structured as a method (not just product labeling).
- Uses a composition formulated as a solution.
- Contains the entire required vehicle set (ethanol + diisopropyl adipate + C12-15 alkyl lactate + cyclomethicone).
- Uses a triazole antifungal (for Claim 1) and, if applicable, the specific triazole (for Claims 2/5).
- Avoids or includes polymeric film forming compounds depending on which claims matter.
- Meets or misses Claim 4 concentration windows.
Key takeaways
- US 11,213,519 claims a nail-surface topical treatment method using a solution formulation with a tightly defined vehicle and a triazole antifungal agent.
- Claims 2 and 5 are locked to a specific triazole structure; substitution can avoid those dependent claims.
- Claims 3 and 6 exclude polymeric film forming compounds, creating a boundary between “solution” systems and polymeric film-lacquer approaches.
- Claim 4 adds the most actionable numeric design-around lever: ethanol ≥ 50% w/w; cyclomethicone < 25% w/w; diisopropyl adipate + C12-15 alkyl lactate total 15 to 50% w/w.
- The practical competitive risk is highest when a product matches (i) solution format, (ii) all required vehicle ingredients, and (iii) the relevant ethanol/cyclomethicone/ester ranges, with additional tightening if the product uses the same specific triazole antifungal.
FAQs
1) Is US 11,213,519 a product claim or a method claim?
It is a method of treatment claim: topical application to the nail surface with an amount and time sufficient to ameliorate onychomycosis symptoms.
2) What is the most specific active ingredient scope in the patent?
Claims 2 and 5 require the triazole antifungal to be (2R,3R)-2-(2,4-difluorophenyl)-3-(4-methylenepiperidine-1-yl)-1-(1H-1,2,4-triazole-1-yl)butane-2-ol.
3) Does the patent cover film-lacquer systems?
It expressly claims a solution in Claim 1 and includes dependent exclusions of polymeric film forming compounds in Claims 3 and 6.
4) Which claim has the most precise formulation numerical constraints?
Claim 4: ethanol ≥ 50% w/w, cyclomethicone < 25% w/w, and diisopropyl adipate + C12-15 alkyl lactate = 15 to 50% w/w total.
5) If a competitor changes concentrations but keeps the same ingredients, which claims are most at risk?
They remain at risk for Claim 1 (ingredient list + solution + triazole antifungal) but may avoid Claim 4 and dependent concentration-specific capture.
References
[1] Claims as provided by the user for United States Patent 11,213,519 (method for treatment of onychomycosis using ethanol, diisopropyl adipate, C12-15 alkyl lactate, cyclomethicone, and a triazole antifungal agent).
