US Patent 11,135,155: What Is Claimed, How Broad the Scope Is, and Where It Sits in the Naloxone Nasal Formulation Landscape
US Patent 11,135,155 claims a liquid nasal spray formulation containing high-concentration naloxone (or a pharmaceutically acceptable salt), water, and a trace chelating agent (with edetate disodium dihydrate singled out), with dependent claims that add ethanol and propylene glycol at defined ranges. The scope is built around three formulation levers: (1) naloxone concentration, (2) chelator type and low ppm-to-percentage range, and (3) cosolvent/hydration system (water plus optional ethanol/propylene glycol).
What do the independent claims cover?
Claim 1: Nasal spray formulation with naloxone + water + chelator (core scope)
Claim 1 is the broadest “composition” anchor. It requires all of the following in a single nasal spray formulation:
- Naloxone (or pharmaceutically acceptable salt): about 5% to about 16% w/w
- Water: present (water is explicitly required in the claim)
- Chelating agent: about 0.001% to about 0.1% w/w
- Chelating scope uses “wherein w/w denotes weight by total weight of the formulation” as the basis for the ranges.
Interpretive impact: the “chelating agent” limitation is numeric and tight. The formulation is not just “with chelator,” it is with chelator in a specific low range.
Claim 9: Liquid spray formulation with naloxone + ethanol + propylene glycol + water + chelator (narrower, but operationally detailed)
Claim 9 adds the cosolvent and hydration composition in one pass. It requires:
- Naloxone (or salt): about 5% to about 16% w/w
- Ethanol: about 20% to about 50% w/w
- Propylene glycol: about 5% to about 10% w/w
- Water: about 35% to about 70% w/w
- Chelating agent: about 0.001% to about 0.1% w/w
Interpretive impact: claim 9 is a “recipe” claim. It locks multiple excipient ranges simultaneously, which materially reduces design-around options that try to keep the chelator while changing solvent system.
How are the dependent claims narrowing the scope?
Chelator specificity (claims 2, 11, 13)
- Claim 2: chelator is edetate disodium dihydrate
- Claim 11: chelator is at a concentration from about 0.005% to about 0.01% w/w
- Claim 13: chelator is edetate disodium dihydrate
Impact:
- The patent has a general chelator range claim (0.001% to 0.1%) and then a fallback to a specific chelator identity (edetate disodium dihydrate).
- Claim 11 narrows chelator content even further for the ethanol/propylene glycol/water system of claim 9.
Ethanol and propylene glycol ranges (claims 3-5, 17-18)
- Claim 3: claim 1 further comprises ethanol and propylene glycol
- Claim 4: ethanol 2% to 50% w/w; propylene glycol 5% to 10% w/w
- Claim 5: ethanol 20% to 50% w/w
- Claim 17: claim 12 further comprises ethanol and propylene glycol
- Claim 18: ethanol 2% to 50% w/w; propylene glycol 5% to 10% w/w
Impact:
- Claim 5 ties ethanol into the same high range used by claim 9.
- Claim 3/4 create overlapping coverage with claim 9 but via dependence from the broader claim 1/12 structure.
Naloxone concentration narrowing (claim 6, plus overlap across the set)
- Claim 6: naloxone (or salt) is about 7% to about 16% w/w
Impact:
- Claim 1 already covers 5% to 16%; claim 6 trims off 5% to 7% while keeping the high-dose end.
- If a competitor targets 6% or 6.5%, they may still fall into claim 1, unless they also exit other limitations (chelator identity/range, ethanol/propyleneglycol, water range).
Water range tailoring (claims 7-8, 14-16, 19)
Water is used in multiple ways: a broad requirement (claim 1) then narrower subranges:
- Claim 7 (dependent from claim 1): water 20% to 95% w/w
- Claim 8: water 30% to 85% w/w
- Claim 14 (dependent from claim 12): water 10% to 90% w/w
- Claim 15: water 20% to 90% w/w
- Claim 16: water 35% to 85% w/w
- Claim 19 (dependent from claim 1): water 10% to 95% w/w
Impact:
- Across dependent claims, water range coverage spans 10% to 95% with multiple interior windows that overlap.
- Practically, if formulation work keeps ethanol/propylene glycol and water in common ranges, a large fraction of likely compositions will still land inside one of these windows.
What is the “scope map” of the claimed formulation space?
Key constraints as claim-built boxes
Below are the explicit numeric constraints that determine whether a competitor falls in-scope.
| Feature |
Claim 1 (nasal spray) |
Claim 9 (liquid spray) |
Narrow dependent windows |
| Naloxone (w/w) |
5% to 16% |
5% to 16% |
Claim 6: 7% to 16% |
| Water (w/w) |
required (range covered via dependents) |
35% to 70% |
Claims 7-8, 14-16, 19: windows 10% to 95% and 30-85%, 35-85% |
| Chelating agent (w/w) |
0.001% to 0.1% |
0.001% to 0.1% |
Claim 11: 0.005% to 0.01% |
| Chelator identity |
any chelating agent within range |
any within range |
Claims 2/13: edetate disodium dihydrate |
| Ethanol (w/w) |
only if added via dependence |
20% to 50% |
Claim 4/5/18: ethanol 2% to 50%; claim 5: 20% to 50% |
| Propylene glycol (w/w) |
only if added via dependence |
5% to 10% |
Claim 4/18: 5% to 10% |
Practical infringement surfaces
A competitor’s formulation can fall into claim 1 even without ethanol/propylene glycol if it satisfies:
- naloxone 5% to 16%,
- water present,
- chelator present in 0.001% to 0.1%.
A competitor’s formulation can fall into claim 9 if it satisfies the full “solvent system box”:
- naloxone 5% to 16%,
- ethanol 20% to 50%,
- propylene glycol 5% to 10%,
- water 35% to 70%,
- chelator 0.001% to 0.1%.
The overlap between claim 1 and claim 9 is large because claim 9 is a stricter subset: it fixes ethanol/propylene glycol ranges and water/solvent balances.
How does the patent handle chelators and composition chemistry risk?
Chelator is the differentiator
The numerical chelator band (0.001% to 0.1% w/w) is small relative to major components but is not negligible. The dependent claims pin down:
- identity: edetate disodium dihydrate
- narrower concentration: 0.005% to 0.01% w/w (in the ethanol/PG system of claim 9)
This structure suggests the patent is guarding against formulations that:
- use naloxone at high concentration,
- retain water-based delivery,
- and use chelation to address stability/compatibility issues.
Design-around reality
A design-around must typically break at least one claim element:
- remove chelator entirely (not claimed),
- lower chelator below 0.001% or raise above 0.1%,
- change chelator identity and also keep it outside the “edetate disodium dihydrate” dependent claims (but claim 1 still captures other chelators inside the band),
- shift out of naloxone 5% to 16% (or 7% to 16% depending on which dependent claim is asserted),
- or shift ethanol/water/propylene glycol ratios outside the claim 9 box (if claim 9 is the target risk).
What is the likely claim interaction and “coverage layering”?
Layering across claim families
The claim set builds layered protection:
- Base: claim 1 covers naloxone + water + any chelator within 0.001% to 0.1%.
- Identity fallback: claims 2 and 13 lock in edetate disodium dihydrate.
- Solvent system: claims 3-5 and 17-18 add ethanol and propylene glycol ranges, with claim 5 aligning ethanol 20% to 50%, consistent with claim 9.
- Concentration fallback: claim 6 restricts naloxone to 7% to 16%.
- Water windows: multiple dependent claims cover wide water bands, likely to cover formulation shifts driven by viscosity, osmolarity, or stability.
Overlap consequences
Because dependent claims are nested, a single accused formulation that matches the broad claim 1 constraints automatically positions for infringement theories via:
- claim 2 if edetate disodium dihydrate is used and falls in the same chelator range,
- claim 6 if naloxone is in 7% to 16%,
- one of the water-window dependents if water aligns,
- claim 3-5 if ethanol/PG are present within their ranges.
How to interpret the landscape relevance for the naloxone nasal spray sector
US patents in this area commonly compete on three axes:
- naloxone concentration and salt form,
- cosolvent and delivery liquid system (water, ethanol, polyols),
- stabilization additives (chelators, buffers, antioxidants) that manage degradation and performance.
US 11,135,155 is specifically a stabilizer-and-solvent system guardrail with a strong quantitative chelator lens. Even without knowing prosecution history or specification, the claim architecture indicates the patent is aimed at formulations where:
- naloxone is present at relatively high w/w levels (5% to 16%),
- the formulation is water-containing,
- trace chelator is used in a narrow band,
- ethanol/propylene glycol systems are employed in meaningful volumes (claim 9 fixes ethanol 20% to 50% and PG 5% to 10%).
What does this mean for competitive freedom-to-operate?
High-risk “hit zones”
A competitor faces elevated patent risk if it formulates into any of these zones:
-
Naloxone 5% to 16% + chelator 0.001% to 0.1% + water-containing liquid nasal spray
- This is the direct claim 1 capture zone.
-
Naloxone 5% to 16% + ethanol 20% to 50% + PG 5% to 10% + water 35% to 70% + chelator 0.001% to 0.1%
- This is the direct claim 9 capture zone.
-
Edetate disodium dihydrate at 0.005% to 0.01% within the ethanol/PG/water system
- This targets claim 11 (and identity via claim 13).
Low-risk zones (from a claim element perspective)
Lower risk arises if the competitor:
- operates outside naloxone 5% to 16%,
- uses no chelator,
- uses chelator outside 0.001% to 0.1%,
- or shifts the solvent system outside claim 9’s fixed multi-variable box.
Key Takeaways
- US 11,135,155 is a quantitative formulation patent: it protects a naloxone (5% to 16% w/w) nasal spray with water and a chelating agent at 0.001% to 0.1% w/w (claim 1).
- Chelator is the core differentiator: dependent claims identify edetate disodium dihydrate and narrow chelator content to 0.005% to 0.01% w/w (claim 11).
- Solvent system layering matters: claim 9 requires a fixed co-solvent system (ethanol 20% to 50%, propylene glycol 5% to 10%, water 35% to 70%) with the same naloxone and chelator ranges.
- Water and concentration dependents are broad and overlap: multiple water windows (10% to 95%, plus interior 30% to 85% and 35% to 85%) reduce the ability to “escape” by minor water shifts.
- Design-around must break a claim element, not merely tweak one parameter: the patent’s nested dependencies and overlapping windows create multiple ways an accused formulation can still land inside claim coverage.
FAQs
1) Is claim 1 broader than claim 9?
Yes. Claim 1 requires naloxone (5% to 16%), water, and chelator (0.001% to 0.1%) but does not require ethanol and propylene glycol. Claim 9 is narrower because it adds specific ethanol, propylene glycol, and water ranges.
2) If a formulation uses a chelating agent outside edetate disodium dihydrate, does it avoid infringement?
It can avoid the dependent claims that specify edetate disodium dihydrate, but it does not automatically avoid claim 1 or claim 9 because those claims capture any chelating agent so long as it is within 0.001% to 0.1% w/w.
3) What is the most restrictive chelator limitation in the claim set?
The tightest explicit chelator concentration is 0.005% to 0.01% w/w (claim 11), tied to the claim 9-like solvent system and composition structure.
4) Which ethanol range drives the strongest risk for the “liquid spray” claim?
For claim 9, ethanol must be about 20% to about 50% w/w.
5) Can a formulation fall into multiple claims at once?
Yes. A single formulation can satisfy claim 1 and multiple dependents (water windows, naloxone window, and ethanol/propylene glycol ranges), and it can also satisfy claim 9 if it matches the full solvent system ranges.
References
[1] US Patent 11,135,155 (naloxone nasal spray formulations with chelating agent; claims as provided in the prompt).
