United States Patent 6,814,953 Scope, Claim Coverage, and Formoterol Nebulizer Kit Patent Landscape (US)

US Patent 6,814,953 claims a formoterol-containing pharmaceutical kit built around a stable aqueous nebulizer solution with defined shelf-life performance and specific formulation parameters (water-based fluid, polar solvent/tonicity agents, buffer identity and concentration, ionic strength, pH, and formoterol free-base concentration). The patent estate is claim-heavy on ranges and specific numerical embodiments (notably ~pH 5.0, citrate buffer at ~5 mM or ~20 mM, ionic strength ~0.05 to ~0.16, and formoterol free base at ~59 µg/mL or ~118 µg/mL). That structure creates two practical enforceability levers: (1) infringement of a narrow, numerically bounded formulation within a kit context; and (2) method infringement for treatment of bronchoconstrictive disorders when the same formulation is administered.

What is US Patent 6,814,953 protecting: a formoterol nebulizer kit or the formulation itself?

Answer: It protects both the kit and the method where the kit/method uses the same stable aqueous formoterol solution (free base or derivative) suitable for direct administration via a nebulizer, with stability and formulation parameters that are operationally measurable.

Core subject matter in the independent claims

Claim 1 (kit):
- A kit comprising:
  - (a) a pharmaceutical composition containing formoterol (or derivative) in a pharmacologically suitable fluid
  - the composition is stable during long-term storage
  - the fluid comprises water
  - the composition is formulated at a concentration suitable for direct administration
  - (b) a nebulizer
Claim 74 (method):
- A method for treating bronchoconstrictive disorders by administering an effective amount of the same kind of formulation (stable, water-based, formoterol or derivative, suitable concentration for direct administration).

What the independent claims do not require

They do not require a particular:
- patient population
- disease subtype naming (beyond “bronchoconstrictive disorders” in claim 74)
- specific buffer type, tonicity agent, pH, ionic strength, or shelf-life numbers in the independent claim
- specific formoterol dosing unit beyond concentration “suitable for direct administration”
- specific nebulizer type (just “a nebulizer”)

What drives infringement reality

The independent claims are broad on concept, but the dependent claims lock in the formulation identity and properties. If a competitor’s product does not meet the stability/performance parameters and/or the specific formulation constraints, it can avoid the numerically bounded dependent claims and may still try to challenge infringement of claim 1/74 via formulation characterization.

What are the key claim limitations in US 6,814,953 and how narrow are they?

Answer: The most limiting features are (i) measurable stability/shelf-life criteria, (ii) buffer identity/concentration, (iii) pH, (iv) ionic strength, and (v) formoterol free-base concentration. Several dependent claims create “switching” effects: changing one parameter can move the product outside the claim.

Stability and shelf-life performance claims

Claim 2: estimated shelf-life
- > 1 month usage time at 25°C
- ≥ 1 year storage time at 5°C
Claim 3: performance
- > about 80% of initial formoterol remains after
  - 1 month usage time at 25°C
  - 1 year storage time at 5°C
Claim 75-76 replicate these for method coverage.

Practical effect: A product that has a different stability profile can avoid these dependent claims even if it uses similar excipients.

Formulation building blocks

Polar solvent / protic solvent:
- Claims 4-5 (kit) and 77-78 (method)
Tonicity adjusting agent (very extensive list):
- Claims 6-8 (kit) and 79-81 (method)
- with the ability to specify “sodium chloride” (Claim 8 and Claim 81)
Buffer:
- Claims 9-14 (kit) and 82-87 (method)
- A very broad menu of buffer systems appears in later dependent claims:
  - citrate/phosphate, acetate, barbital, borate, Britton-Robinson, cacodylate, citrate, collidine, formate, maleate, phosphate systems, HEPES-family, MES/MOPS/TES/HEPES variants, glycine buffers, triethanolamine, and more.
- Then the patent narrows to citrate buffer plus buffer concentration ranges:
  - Claim 12-14 (kit): 0.01 mM to 150 mM; then 1 mM to 20 mM; then about 5 mM
  - Claim 11: buffer is citrate
- Claim 60-65 expands citrate buffer concentration embodiments to ~20 mM plus more specific ionic strength/pH combinations.

Ionic strength and pH

Ionic strength:
- Claim 15: about 0 to about 0.4
- Claim 16: about 0.05 to about 0.16
- analogous Claim 88-89 for methods
pH:
- Claim 17: about 2.0 to about 8.0
- Claim 18: 4.0 to 6.0
- Claim 19: 4.5 to 5.5
- Claim 20: about 5.0
- analogous Claim 90-93 for methods

Practical effect: These two parameters are easy to measure during formulation characterization but may be non-trivial to change without affecting stability or nebulization performance.

Formoterol free-base concentration

Claim 21-23: 5 µg/mL to 2 mg/mL; then 10 µg/mL to 1 mg/mL; then 50 µg/mL to 200 µg/mL
Numeric embodiments:
- Claim 24: about 59 µg/mL
- Claim 25: about 118 µg/mL
The same numeric embodiments repeat in method form: Claims 97-98.

Specific “composition definition” embodiments

The patent includes dependent claims that tie together multiple parameters simultaneously:

Claim 43-46 (kit):
- formoterol free base ~59 or ~118 µg/mL
- aqueous saline comprising sodium chloride
- citrate buffer at ~5 mM or ~2 mM
- ionic strength ~0.05 to ~0.16
- pH ~5.0
Similar “kit composition” embodiments appear again later (Claims 116-119, 124-129, etc.), and parallel method claims occur (116-119 analogs in method section).

Practical effect: Competitors typically make changes in at least one of (formoterol concentration, pH, ionic strength, buffer identity, buffer concentration, tonicity agent). Matching all at once is harder, but each parameter change can selectively avoid some dependent claims while still falling into others.

How do kit claims vs method claims affect enforcement strategy for US 6,814,953?

Answer: The patent provides two infringement pathways:

Product/kit infringement (kit claims 1-69)
Use/method infringement (method claims 74-146)

Kit claims are the primary “commercial” hook

Kits explicitly recite a nebulizer and a stable aqueous formoterol composition.
If a nebulizer solution is sold with a nebulizer, the kit claims are the most straightforward to test.

Method claims shift focus to administration

Method claims focus on administering the formulation for bronchoconstrictive disorders.
This can be used in cases where distribution and use patterns matter, or where the kit is separated into components but still meets “administering” under the method claim.

Dependent claim overlap

Many dependent claims mirror each other (kit and method) on:

stability
excipients (polar solvent, tonicity agent)
buffers (especially citrate)
ionic strength
pH
formoterol concentration.

What shelf-life and stability evidence is required to practice around US 6,814,953?

Answer: The patent’s dependent claims require that the formulation is stable with quantifiable shelf-life and potency retention.

Minimum stability criteria to stay inside claims

Usage at 25°C: >1 month
Storage at 5°C: ≥1 year
Potency retention: >80% after 1 month at 25°C and 1 year at 5°C.

Design-around lever

To avoid dependent claims 2-3 (and 75-76), the stability profile must fail one of those thresholds. That can be done by:

changing excipient system
changing pH or ionic strength
changing buffer identity/concentration
changing formoterol concentration
changing solvent system (protic solvent requirements appear in dependent claims).

Because the patent also includes broad independent claims without numeric thresholds, the stability avoidance may not eliminate all coverage. It reduces the chance of meeting dependent claim elements.

What formulation parameters are explicitly claimed: pH, ionic strength, buffer, and excipients?

Answer: The patent is effectively a formulation claim set around a stable aqueous formoterol solution for direct nebulizer administration.

pH matrix

Broad: 2.0 to 8.0 (Claim 17 / 90)
Narrow: 4.0 to 6.0 (Claim 18 / 91)
Narrower: 4.5 to 5.5 (Claim 19 / 92)
Tight: about 5.0 (Claim 20 / 93)

Ionic strength matrix

Broad: 0 to 0.4 (Claim 15 / 88)
Narrow: 0.05 to 0.16 (Claim 16 / 89)

Buffer systems

Many buffer options are listed.
The “tightest” dependent claims are:
- citrate buffer (Claims 11, 28 and analogous method claims)
- buffer concentration about 5 mM (Claims 14, 31, 48, 51 and related)
- buffer concentration about 20 mM (Claims 61, 63-65, 66-68 and related)
- citrate buffer with defined ionic strength and pH (Claims 65, 67, 65-style combinations)

Tonicity agent

Very broad list appears in dependent claims 7 and 80.
Sodium chloride singled out in:
- Claim 8 (kit)
- Claim 81 (method)

Formoterol concentration

Broad: 5 µg/mL to 2 mg/mL (Claim 21)
Intermediate: 10 µg/mL to 1 mg/mL (Claim 22)
Narrow: 50 µg/mL to 200 µg/mL (Claim 23)
Specific numeric: ~59 µg/mL (Claim 24), ~118 µg/mL (Claim 25)

Which additional agents can be present in US 6,814,953 kits (and how broad is that scope)?

Answer: The patent allows combination kits or co-therapy additions via dependent claims, but those additions are permissive. The key limiting elements still include the stable aqueous formoterol composition.

Broad adjuncts (non-exhaustive examples in claim 57 and claim 130)

β2-adrenoreceptor agonist
dopamine receptor agonist
IL-5 inhibitor
antisense modulator of IL-5
tryptase inhibitor
tachykinin receptor antagonist
milrinone or milrinone lactate
leukotriene receptor antagonist
5-lipoxygenase inhibitor
anti-IgE antibody

Practical effect: This is a broad “combination” umbrella. If a competitor uses formoterol nebulizer solution in the claimed stable formulation, adding any of these adjuncts can still fall within dependent claim coverage.

Anticholinergic additions

Claims 68-73 (kit) and 141-146 (method)
- ipratropium bromide, oxitropium, atropine methyl nitrate, tiotropium bromide, glycopyrronium bromide
- specific concentrations ranges for ipratropium and tiotropium
  - ~5 µg/mL to ~5 mg/mL (Claims 71 and 73)

How does US 6,814,953 compare with typical formoterol nebulizer patent claim patterns?

Answer: It follows a common formulation IP pattern but with unusually dense numerical dependency:

Many formulation patents protect “stable aqueous solution at defined pH/ionic strength/buffer.”
This patent adds explicit potency retention and prescriptive concentrations (including specific values around 59 and 118 µg/mL) and ties them into kit and method claims.

Claim architecture

Broad independent claim: kit/method using stable aqueous formoterol for direct administration via nebulizer.
Dependent claim scaffolding:
- stability performance
- solvent and tonicity systems
- buffer identity and concentration (with citrate emphasized in tighter claims)
- ionic strength and pH narrowing
- explicit formoterol free-base concentrations
- combined parameter embodiments (composition recitals)
- adjunct/co-administration expansions.

Enforcement implication

If a competitor’s marketed nebulizer solution uses a citrate-buffered saline system around pH 5 and ionic strength 0.05-0.16 with sodium chloride and formoterol at ~59 or ~118 µg/mL, the dependent claims become highly actionable.

How many patents cover the same concept area as US 6,814,953 in the US?

Answer: Not enough information is provided to compile an accurate “count” or to map the full US patent family landscape without relying on external database retrieval. The claim text alone does not specify:

assignee
filing date
prosecution history
related continuations
citations
family members
whether this is a continuation or part of a larger formulation portfolio.

What is the patent expiration timing for US 6,814,953 and when does exclusivity end?

Answer: Not enough information is provided to determine expiration or statutory adjustment:

filing date and non-provisional date are not stated
application status and potential PTA/PTAB outcomes are not stated
maintenance status is not provided.

What is the Orange Book status of US 6,814,953 and what FDA product does it map to?

Answer: Not enough information is provided to map the patent to a specific FDA-listed drug product (Orange Book requires NDA/ANDA mapping and listed patent numbers tied to a particular product). The claim text does not identify:

the drug product name
NDA/ANDA number
dosage form code
listed use codes.

What Paragraph IV or generic entry risks exist for the formulation claimed by US 6,814,953?

Answer: Not enough information is provided to determine current generic or follow-on applicant threats, because risk depends on:

whether an ANDA is pending or approved for the specific nebulizer solution formulation
whether the patent is listed for that product in Orange Book
whether Paragraph IV notices exist and the legal posture.

What patent litigation or settlements involve US 6,814,953?

Answer: Not enough information is provided to identify litigation dockets, venue, parties, asserted claims, or settlement terms tied to US 6,814,953.

Key claim coverage chart for US 6,814,953

Claim element (limitation)	Covered in kit claims	Covered in method claims	Design-around direction
Kit includes stable aqueous formoterol solution + nebulizer	Claim 1	N/A	Remove nebulizer “kit” packaging, or avoid stable formulation elements
Stable long-term storage (no numeric threshold required in claim 1)	Claim 1	Claim 74	Alter stability characteristics so “stable during long term storage” is not met (harder for claim 1)
Shelf-life: >1 month usage @25°C; ≥1 year storage @5°C	Claim 2	Claim 75	Demonstrate failure of shelf-life thresholds
Potency retention: >80% remaining	Claim 3	Claim 76	Shift stability/potency decay profile
Polar solvent; protic solvent	Claims 4-5	Claims 77-78	Change solvent system
Tonicity agent including sodium chloride option	Claims 6-8	Claims 79-81	Use non-listed tonicity system or different concentration strategy
Buffer required (broad buffer menu)	Claim 9	Claim 82	Use no buffer or use non-listed buffers (if enforceable)
Buffer tightened to citrate; concentration ranges (e.g., ~5 mM)	Claims 11-14	Claims 84-87	Use different buffer type/concentration
Buffer concentration and citrate embodiments (e.g., ~20 mM)	Claims 61-65, 66-68	Claims 133-140	Avoid ~20 mM citrate combinations tied to pH/ionic strength
Ionic strength ranges	Claims 15-16	Claims 88-89	Shift ionic strength outside 0.05-0.16 if needed
pH tightening to about 5.0	Claims 17-20	Claims 90-93	Shift pH outside 4.5-5.5 or avoid exactly ~5.0 targets
Formoterol free base concentration embodiments (e.g., 59 and 118 µg/mL)	Claims 21-25	Claims 94-98	Adjust concentration beyond the specific numeric options
Full “composition recitals” tying concentration + NaCl + citrate buffer + ionic strength + pH	Claims 43-46; 116-119	Claims 116-119 (method analogs)	Change at least one coupled parameter so the combined recital is not met
Adjunct agent inclusions (IL-5 etc.)	Claim 57	Claim 130	Not a main avoidable parameter if formulation itself is avoided; otherwise irrelevant
Anticholinergic add-ons (ipratropium/tiotropium etc.)	Claims 68-73	Claims 141-146	Only if formulation already matches; otherwise irrelevant

Key Takeaways

US 6,814,953 is built around a stable, water-based formoterol solution for nebulizer administration sold as a kit and used in a treatment method.
The actionable claim scope is concentrated in dependent claims that require:
- measured stability (>1 month at 25°C usage; ≥1 year at 5°C storage; >80% retained)
- a tightly specified formulation envelope: pH ~5.0, ionic strength ~0.05 to 0.16, citrate buffer at ~5 mM or ~20 mM, and formoterol free base at specific concentrations (notably ~59 µg/mL and ~118 µg/mL).
Enforcement leverage increases sharply if an accused product matches the composition recitals that couple multiple parameters (formoterol concentration + NaCl + citrate buffer concentration + ionic strength + pH).
The patent also supports combination kits/methods by permissive dependent claims (adjunct biologics and anticholinergics), but these do not substitute for meeting the stable aqueous formoterol formulation limitations.

FAQs

Do the independent kit claim (Claim 1) and method claim (Claim 74) require citrate buffer or pH 5.0?
How do the dependent claims’ “about 59 µg/mL” and “about 118 µg/mL” formoterol free-base concentrations affect infringement risk for alternative strengths?
If a competitor changes only buffer concentration (for example from ~5 mM to ~7 mM citrate), which dependent claim elements are likely avoided?
Does adding ipratropium or tiotropium in a co-therapy nebulizer kit expand infringement exposure only if the formoterol solution still matches the stable aqueous formulation envelope?
Which formulation parameter is the most practical “single-variable” design-around: pH, ionic strength, buffer concentration, or formoterol concentration?

References (APA)

US Patent 6,814,953, “A kit and method for administering stable aqueous formoterol for nebulization,” claim set provided in prompt.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2002244211	⤷ Start Trial
Canada	2438544	⤷ Start Trial
European Patent Office	1381346	⤷ Start Trial
Spain	2554476	⤷ Start Trial
Japan	2004532217	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: 6,814,953