United States Patent 6,264,923: Scope, Claim Coverage, and US Landscape for Ciclesonide/HFC-Ethanol Aerosol Formulations
What does US 6,264,923 claim at a high level?
US Patent 6,264,923 is a formulation patent centered on an aerosol/pressurized composition that combines:
- Drug: a compound of Formula (I) where R1 is 1-butyl, 2-butyl, cyclohexyl, or phenyl, and R2 is acetyl or isobutanoyl.
- Specific embodiment: Claim 2 limits Formula (I) to ciclesonide.
- Delivery vehicle: a hydrofluorocarbon (HFC) propellant chosen from:
- 1,1,1,2-tetrafluoroethane (HFC-134a)
- 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea)
- or mixtures of them.
- Cosolvent / solubilizer: ethanol in a defined amount “effective to solubilize” Formula (I).
- Optional component: surfactant, only “optionally” in the base independent claim; Claim 3 makes a narrower “free of surfactant” variant.
- Concentration and ratio control: multiple dependent claims pin down % ethanol by weight, mg/mL ciclesonide, and an example ratio of ethanol:HFC-134a by weight.
The patent’s enforceable value is driven by the tight matrix of: (i) ciclesonide (or the Formula I analog set), (ii) ethanol + specific HFC(s), and (iii) defined concentration/solubilization and optional surfactant exclusion.
What is the exact claim scope and what is mandatory vs optional?
Independent claim 1: the core enforceable boundary
Claim 1 requires all of the following (no “optional” language for the major elements):
- Pharmaceutical composition comprising
- Therapeutically effective amount of a compound of Formula (I) where:
- R1 ∈ {1-butyl, 2-butyl, cyclohexyl, phenyl}
- R2 ∈ {acetyl, isobutanoyl}
- Propellant selected from:
- HFC-134a (1,1,1,2-tetrafluoroethane),
- HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane),
- and mixtures thereof
- Ethanol “in an amount effective to solubilize” Formula (I)
- Optionally a surfactant
Mandatory: Formula (I) identity class; HFC propellant selection; ethanol solubilization function.
Optional: surfactant.
This structure is typical of formulation patents where the inventiveness is tied to the solubilization behavior of the steroid in a particular HFC/ethanol aerosol system.
Dependent claim 2: locks Formula (I) to ciclesonide
Claim 2 narrows Claim 1 to:
- Formula (I) = ciclesonide
All Claim 1 elements remain mandatory, with the only change being the specific drug identity.
Dependent claim 3: surfactant-free variant
Claim 3 narrows Claim 1 by adding:
- composition is “free of surfactant”
This creates a clean separation between formulations that use surfactants (still within Claim 1) and surfactant-free versions that fall only within Claim 3.
Dependent claims 4-7: ethanol weight % windows
These claims specify increasingly narrow ethanol bands while keeping all other elements of Claim 1 mandatory:
- Claim 4: 3% to 25% by weight ethanol
- Claim 5: 5% to 20% by weight ethanol
- Claim 6: 7% to 12% by weight ethanol
- Claim 7: 8% by weight ethanol
Dependent claim 8: ciclesonide dose concentration (mg/mL)
- Claim 8: if Claim 2 applies (ciclesonide), then the formulation comprises:
Dependent claims 9-10: propellant selection narrowing
- Claim 9: propellant is HFC-134a
- Claim 10: propellant is HFC-227ea
These claims do not add ethanol windows or mg/mL windows unless they also combine with other dependences. They carve out which propellant is used.
Dependent claim 11: aerosol canister + dispensing valve system claim
Claim 11 shifts from composition-only to a device-and-formulation combination:
- A pharmaceutical aerosol formulation contained in an aerosol canister equipped with a dispensing valve, comprising:
- Formula (I) compound (with the same R1/R2 definitions),
- a hydrofluorocarbon propellant,
- cosolvent (ethanol implied by the context of Claim 1) in solubilizing amount.
This claim is relevant for enforcement because it can attach to commercial packaging rather than only formulation recipe, depending on product design.
Dependent claim 12: specific ratio embodiment (ethanol:HFC-134a) and ciclesonide concentration
Claim 12 is the most “product-like” limitation set:
- ciclesonide concentration: 1-5 mg/mL
- blend: ethanol : HFC-134a by weight ratio 8:92
This is a narrow carve-out that is likely intended as a worked example with a crisp scope.
What is covered in practice: formula set vs ciclesonide vs propellant?
Coverage map (what must be true)
| Element |
Claim 1 (baseline) |
Claim 2 (ciclesonide) |
Claim 3 (surfactant-free) |
Claim 9-10 (specific HFC) |
Claim 12 (ratio example) |
| Drug identity |
Formula (I) set |
Ciclesonide |
Same as Claim 2 |
Same as prior claim |
Ciclesonide |
| HFC propellant |
HFC-134a or HFC-227ea or mixture |
Same |
Same |
Claim 9 = HFC-134a; Claim 10 = HFC-227ea |
HFC-134a only |
| Ethanol |
Required; solubilizing amount |
Required |
Required |
Required |
8% ethanol |
| Surfactant |
Optional |
Optional |
Excluded |
Optional |
Not stated (but Claim 12 depends from which claim? it depends on Claim 9 or 2 context as written) |
| Ethanol % |
“Effective to solubilize” |
Same |
Same |
Same |
1-5 mg/mL ciclesonide + 8:92 ethanol:HFC-134a |
| Ciclesonide mg/mL |
Not limited in Claim 1 |
Range in Claim 8 |
Same |
Same |
1-5 mg/mL |
Key point for freedom-to-operate: if an alternative product uses ciclesonide but changes either propellant identity (e.g., using a different HFC or HFO) or changes ethanol presence/amount outside these windows or eliminates ethanol as cosolvent, it may avoid certain dependent claims. But Claim 1 can still capture compositions if ethanol is present at solubilizing amount and the propellant is still one of the two HFCs in-scope.
How strong is the structure of claim language against design-arounds?
The claim language has three characteristics that reduce design-around options:
-
Propellant is restricted to two specific HFCs (plus mixtures)
If a product uses different HFCs/HFC blends or uses non-HFC propellants, it can fall outside Claim 1’s propellant “selected from” clause.
-
Ethanol is required by function (“amount effective to solubilize”)
This creates a functional boundary that can be met across a range of ethanol amounts, even if the exact percentages do not match dependent-claim windows. Dependent claims (4-7, 12) provide additional numerical constraints, but Claim 1 does not require an exact ethanol %. The enforceability hinges on whether ethanol is present in an amount that solubilizes the drug in the chosen propellant system.
-
Drug identity is narrow in practice (ciclesonide is explicitly included)
While Claim 1 includes Formula (I) broader than ciclesonide (R1 and R2 variants), Claim 2 squarely covers ciclesonide. For competing ciclesonide aerosols, Claim 2+Claim 1 elements drive risk.
Where is the likely overlap with other US formulation families?
Because the claims are formulation-centric (drug + specific HFC propellants + ethanol), the patent landscape risk typically comes from:
- Later filings that also use ciclesonide in HFC-134a and/or HFC-227ea with ethanol cosolvent and optionally surfactant.
- Continuations or improvements that tweak ethanol % bands, ciclesonide concentration ranges, or surfactant inclusion/exclusion while keeping the same propellant framework.
Practically, the tightest “at-once” overlap is with products that match these specifics:
- ciclesonide + HFC-134a + ethanol as cosolvent
- 8% ethanol systems and/or 1-5 mg/mL ciclesonide at ethanol:HFC-134a = 8:92
- surfactant-free embodiments
What is the US infringement-relevant “claim chart” for a hypothetical product?
An asserted claim scenario would typically test these conditions:
- Drug: is the API ciclesonide (Claim 2 trigger) or within Formula (I) (Claim 1 trigger)?
- Propellant: is the pressurized aerosol containing HFC-134a and/or HFC-227ea (Claim 1 trigger; Claims 9-10 specify)?
- Ethanol: is ethanol present at a level that functions to solubilize the ciclesonide in the HFC propellant system (Claim 1 trigger)?
- Surfactant: is surfactant present (Claim 3 trigger only if surfactant-free)?
- Quantitative constraints:
- ethanol %: 3-25 / 5-20 / 7-12 / 8% (Claims 4-7)
- ciclesonide dose: 1-8 mg/mL (Claim 8)
- ratio: ethanol:HFC-134a of 8:92 and ciclesonide 1-5 mg/mL (Claim 12)
If a commercial product meets all Claim 1 limitations, it can land within independent claim coverage even if it misses all dependent numerical windows.
How do the dependent claims stratify risk for product positioning?
Ethanol window strategy (Claims 4-7)
- A formulation with ethanol outside 3-25% by weight is less likely to fall under Claims 4-7.
- But Claim 1 does not require those windows; it only requires ethanol in a solubilizing amount. So risk does not disappear unless ethanol is removed or reduced below a level that would plausibly be “effective to solubilize.”
Surfactant strategy (Claim 3)
- Claim 3’s “free of surfactant” is a narrowing limitation. If a product includes surfactant, it may avoid Claim 3, but still face Claim 1 risk because surfactant is optional in Claim 1.
Propellant strategy (Claims 9-10)
- Changing from HFC-134a to HFC-227ea (or vice versa) changes which dependent claim is potentially implicated, but does not remove coverage under Claim 1 because both HFCs are in the independent claim’s list.
Packaging strategy (Claim 11)
- Claim 11 can matter when the product is marketed as a pressurized aerosol in an aerosol canister with a dispensing valve, which is typical for metered-dose inhaler/pressurized aerosol devices.
- If a competitor uses a substantially different delivery system (no aerosol canister with dispensing valve), Claim 11 may be avoidable, while Claim 1 still depends only on composition.
Patent landscape implications (US) for a ciclesonide aerosol program
Within the US, the landscape implied by this patent class is driven by:
- HFC propellant choice (HFC-134a and HFC-227ea),
- ethanol as cosolvent (with “solubilizing amount” as a functional hook),
- numerical formulation specs that can be used both to claim and to engineer around.
For commercial planning, the most important reading of the landscape is not the number of patents, but whether competitor products are likely to share the same HFC + ethanol + solubilization pairing. For ciclesonide aerosol programs, those are the high-probability common denominators.
Key Takeaways
- US 6,264,923 claims pressurized pharmaceutical compositions where ciclesonide (Claim 2) is formulated in HFC-134a and/or HFC-227ea with ethanol at a solubilizing amount (Claim 1).
- Surfactant is optional in Claim 1 and excluded in Claim 3, enabling differentiation between surfactant-containing and surfactant-free embodiments.
- The strongest numerically bounded coverage is in dependent claims: 8% ethanol (Claim 7) and ethanol:HFC-134a = 8:92 with 1-5 mg/mL ciclesonide (Claim 12).
- Design-around levers are primarily: (i) removing ethanol as solubilizing cosolvent, and/or (ii) using propellants outside the two-allowable HFC list, and/or (iii) changing delivery format to avoid device-style coverage in Claim 11.
FAQs
1) Does Claim 1 require surfactant?
No. Surfactant is optional in Claim 1. Claim 3 is the surfactant-free limitation.
2) What propellants are explicitly in-scope?
HFC-134a (1,1,1,2-tetrafluoroethane) and HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane), including mixtures (Claim 1).
3) Where does the patent pin down ethanol as a percentage?
Claims 4-7 define ethanol bands (3-25%, 5-20%, 7-12%, and exactly 8%). Claim 1 itself relies on a functional “solubilize” requirement.
4) Is ciclesonide concentration capped in the independent claim?
No. mg/mL limits appear in dependent claim 8 (1-8 mg/mL) and the more specific dependent claim 12 (1-5 mg/mL).
5) Does Claim 11 cover the formulation in a device context?
Yes. Claim 11 requires an aerosol canister with a dispensing valve containing the formulation.
References
[1] United States Patent 6,264,923. “Pharmaceutical aerosol formulations.” (Claim set as provided by user.)
