US Patent 6,702,997: Scope, Claims, Expiration, and Albuterol Patent Landscape

US Patent 6,702,997 covers a pediatric asthma treatment method using sterile, benzalkonium-chloride-free, premixed and premeasured racemic albuterol sulfate inhalation solution supplied in a single-dose container. The claims are directed to administration, dosage ranges, 12-month therapeutic stability, pediatric labeling, and specified adverse-reaction information.

The patent is a method-of-treatment patent, not a broad composition patent. Its commercial relevance depended on whether a competing product both matched the claimed unit-dose nebulizer formulation and was marketed for children ages 2 to 12 with the required labeling. The patent term has expired, eliminating current US patent exclusivity based on this patent.

What does US Patent 6,702,997 protect?

The patent protects a specific combination of product attributes and treatment steps:

Claim limitation	Required feature
Patient population	Children 2 to 12 years old
Disease	Asthma
Therapeutic effect	Inducing bronchodilation or relieving bronchospasm
Active ingredient	Racemic albuterol sulfate
Dosage form	Aqueous inhalation solution for nebulization
Packaging	At least one single dispensing container
Manufacturing/formulation status	Sterile, premixed, premeasured
Preservative limitation	Benzalkonium chloride-free
Stability	Therapeutically effective after 12 months of storage
Labeling	Indication, dosage, administration, and adverse-reaction information
Claimed adverse events	Otitis media and, in some claims, asthma exacerbation

The claims do not cover every albuterol product. A product lacking the required single-dose container, pediatric indication, benzalkonium-chloride-free formulation, 12-month stability, or racemic albuterol sulfate limitation would fall outside at least one express limitation.

The patent’s core commercial concept was the use of preservative-free, unit-dose albuterol nebulizer solution for pediatric asthma treatment. The claims combine formulation characteristics with a method of administration and labeling requirements.

How many independent claims does US 6,702,997 have?

Based on the claims supplied, the patent has two independent claims:

Claim 1, which covers administration of a single-dose, stable, benzalkonium-chloride-free racemic albuterol sulfate solution to a child aged 2 to 12.
Claim 4, which recites narrower dosage ranges and requires the provision of indication, dosage, administration, and adverse-reaction data.

Claims 2, 3, and 5 through 9 depend on Claim 1 or Claim 2 and add labeling or dosage limitations.

Claim 1 scope

Claim 1 is the broadest independent claim. It requires all of the following:

Administration to a child between 2 and 12 years old.
Asthma as the underlying condition.
A single dispensing container.
A sterile aqueous solution.
No benzalkonium chloride.
Premixed and premeasured presentation.
Racemic albuterol sulfate as the active ingredient.
A unit dose between approximately 0.21 mg and 1.90 mg.
Suitability for nebulization.
Therapeutic effectiveness after 12 months of storage.

The phrase “consisting essentially of” narrows the permissible active-ingredient composition while potentially allowing inactive ingredients that do not materially alter the claimed product’s basic and novel characteristics. Infringement analysis would likely focus on whether another active pharmaceutical ingredient or functionally significant additive changes the formulation’s claimed identity.

Claim 4 scope

Claim 4 is narrower in dosage but broader in its express labeling provisions. It covers selected dosage bands:

Approximately 0.5 mg to 0.6 mg
Approximately 0.7 mg to 0.8 mg
Approximately 0.9 mg to 1.0 mg
Approximately 1.21 mg to 1.40 mg
Approximately 1.41 mg to 1.60 mg
Approximately 1.61 mg to 1.80 mg

Claims 6 through 9 narrow the dosage further to approximately:

0.70 mg to 0.80 mg
1.41 mg to 1.60 mg
0.75 mg
1.50 mg

The 0.75 mg and 1.50 mg claims are particularly narrow and would require proof that the administered unit dose falls within those approximate amounts.

What formulations are protected by US 6,702,997?

The patent protects a formulation only when the formulation is used in the claimed pediatric treatment method and satisfies the claim limitations.

The relevant formulation profile is:

Formulation characteristic	Relevance
Racemic albuterol sulfate	Required active ingredient
Aqueous solution	Required dosage form
Nebulizer-compatible	Required use characteristic
Benzalkonium chloride-free	Express limitation
Sterile	Express limitation
Premixed	Express limitation
Premeasured	Express limitation
Single-dose container	Express packaging limitation
Twelve-month therapeutic stability	Express stability limitation

The patent does not claim levalbuterol as the active ingredient. Levalbuterol is the R-isomer of albuterol and is chemically distinct from the claimed racemic mixture. Products containing levalbuterol would generally require a separate claim analysis.

The patent also does not broadly cover metered-dose inhalers, dry-powder inhalers, multidose nebulizer bottles, or oral albuterol products. Those dosage forms do not ordinarily satisfy the single-container aqueous nebulizer formulation limitations.

What dosage strengths are covered by the patent?

The claims cover a broad approximate range from about 0.21 mg to about 1.90 mg, with narrower dependent claims focused on approximately 0.75 mg and 1.50 mg.

Commercial pediatric nebulizer products historically used strengths such as 0.63 mg/3 mL and 1.25 mg/3 mL. Those labeled strengths do not automatically establish infringement. The relevant question is the amount of racemic albuterol sulfate in the unit dose and whether the marketed use, container, formulation, stability, and pediatric labeling satisfy every claim limitation.

Claimed amount	Potential commercial relevance
0.21-1.90 mg	Broadest claimed amount range
0.50-0.60 mg	Narrow Claim 4 band
0.70-0.80 mg	Claims 4 and 6
0.90-1.00 mg	Claim 4
1.21-1.40 mg	Claim 4
1.41-1.60 mg	Claims 4 and 7
1.61-1.80 mg	Claim 4
0.75 mg	Claim 8
1.50 mg	Claim 9

The use of “about” creates a potential claim-construction issue. Courts generally assess the intrinsic evidence, specification, prosecution history, and technical meaning of the approximation. Small deviations from a stated amount are not automatically outside the claim.

When did US Patent 6,702,997 lose exclusivity?

US Patent 6,702,997 was granted to Dey, L.P. in 2004. Its term was tied to an April 2000 priority date and expired in approximately April 2021 under the applicable US patent-term framework. The patent is therefore no longer an enforceable US exclusion right.

Event	Date
Earliest priority period	April 2000
US patent grant	2004
Approximate patent expiration	April 2021
Current status	Expired

The expiration ended infringement exposure under this patent, but it did not remove regulatory requirements for albuterol nebulizer products. FDA approval, current labeling, manufacturing controls, sterility, container-closure integrity, and drug-supply requirements remain separate obligations.

What is the FDA and Orange Book status of the patent?

The patent was associated with the pediatric albuterol nebulizer product category, including products marketed by Dey and related manufacturers. FDA Orange Book relevance depends on whether the patent was listed against a specific approved new drug application and whether the listing remained active during the relevant period.

Patent listing does not itself establish validity or infringement. An Orange Book-listed patent can be challenged through a Paragraph IV certification, and the patent holder may sue within the statutory period. The listing also does not extend the patent term.

For an abbreviated new drug application, a Paragraph IV certification against an unexpired listed patent could trigger patent litigation and, in some circumstances, a 30-month FDA approval stay. That mechanism became commercially immaterial after expiration of the patent in 2021 because an expired patent cannot ordinarily support a continuing Orange Book-based exclusion period.

The FDA-approved product label remains important because the claims expressly incorporate pediatric indications and adverse-reaction information. FDA labeling for albuterol inhalation solutions identifies pediatric asthma and bronchospasm uses, dosage instructions, and adverse reactions. A generic applicant would have assessed both the patent claims and the reference-listed drug’s labeling before approval.

Which companies challenged or competed with the patent?

The competitive field included:

Dey, L.P., associated with the AccuNeb product and the patent estate.
Nephron Pharmaceuticals, a major supplier of unit-dose inhalation solutions.
Teva Pharmaceuticals.
Sandoz and other generic manufacturers.
Specialty respiratory-product manufacturers supplying albuterol sulfate inhalation solution.

Generic competition could arise through an ANDA for a product therapeutically equivalent to the reference product. A generic applicant would typically evaluate:

Whether the product used racemic albuterol sulfate.
Whether the product was supplied in a unit-dose container.
Whether it was benzalkonium-chloride-free.
Whether the proposed labeling covered pediatric patients ages 2 to 12.
Whether the formulation had the claimed 12-month stability.
Whether the patent was listed and unexpired when the certification was filed.

No current commercial barrier remains under US 6,702,997 because the patent has expired.

How strong is the patent estate for pediatric albuterol nebulizer products?

The patent was commercially specific but legally narrow in several respects.

Strengths

The claim combination was difficult to design around if a competitor sold the same type of pediatric unit-dose product. The claims captured multiple practical features used in commercial nebulizer products:

Sterile aqueous presentation.
Preservative-free formulation.
Unit-dose packaging.
Pediatric asthma labeling.
Therapeutic stability.
Defined dosage amounts.

The combination of formulation, packaging, indication, and labeling limitations also created a fact-intensive infringement analysis.

Weaknesses

The claims had several potential validity and enforcement vulnerabilities:

Albuterol nebulizer solutions and pediatric bronchodilation were known technologies.
Unit-dose packaging and sterile aqueous solutions were established pharmaceutical practices.
Benzalkonium-chloride-free formulations could be challenged as an obvious formulation choice where preservative-related toxicity or tolerability was known.
“Therapeutically effective following storage for 12 months” may raise questions about the test conditions, storage parameters, and objective boundaries.
Claims requiring provision of adverse-reaction data may face enforceability issues if the limitation is treated as labeling content rather than a meaningful treatment step.
Claims 3 and 4 contain apparent drafting or transcription errors, including “ottis media,” “coritainer,” and “wit asthma.” The effect depends on the official issued patent text and prosecution history.

The patent’s commercial value was strongest before generic unit-dose albuterol products had broad market access. Its present patent value is zero as an exclusion right because the term has ended.

What patent litigation and settlement risks affected the product category?

The primary historical risk was an ANDA Paragraph IV challenge before patent expiration. A generic applicant could have argued that the claims were invalid or not infringed because:

The product did not meet the pediatric age limitation.
The formulation was not benzalkonium-chloride-free.
The dose was outside the claimed range.
The product was not supplied in a single dispensing container.
The formulation did not satisfy the 12-month stability limitation.
The proposed labeling did not include the claimed adverse-reaction information.
The claims were obvious over prior albuterol nebulizer solutions and pediatric treatment references.

A patent holder could have responded with an infringement action under 35 U.S.C. §271(e)(2), seeking the statutory approval stay and damages or injunctive relief if the patent remained enforceable.

No continuing settlement restriction can be inferred from the patent alone. Settlement terms, launch dates, licenses, and covenants not to sue require review of the specific litigation docket and agreement.

Are biosimilar risks relevant to US 6,702,997?

No. Biosimilar law is not relevant to this patent because racemic albuterol sulfate is a small-molecule drug, not a biologic subject to the Biologics Price Competition and Innovation Act pathway.

The relevant competitive pathways are:

ANDA approval for a generic inhalation solution.
505(b)(2) approval for a product relying partly on existing literature or an approved product.
An NDA for a materially different formulation, device, or indication.

What manufacturing and intellectual-property barriers remain?

The expired patent does not eliminate technical barriers. Commercial manufacturers still must control:

Sterility assurance.
Fill volume and dose uniformity.
Container-closure integrity.
Compatibility between the solution and plastic unit-dose containers.
Stability over the labeled shelf life.
Nebulizer performance.
Extractables and leachables.
Microbiological quality.
Accurate pediatric labeling.

Potential surviving IP may exist around container materials, filling processes, nebulizer systems, device interfaces, manufacturing equipment, or newer formulations. Those rights are separate from US 6,702,997 and do not revive its expired claims.

How does this patent compare with competing albuterol patent categories?

Patent category	Typical subject matter	Relevance to US 6,702,997
Composition patent	Chemical compound or salt	6,702,997 is not primarily a composition patent
Formulation patent	Excipients, preservatives, pH, stability	6,702,997 includes formulation limitations but claims a treatment method
Packaging patent	Unit-dose container or container material	Packaging is a limitation, not the sole invention
Method-of-use patent	Patient group, disease, dose, treatment	6,702,997 is principally this type
Device patent	Nebulizer hardware or delivery system	Not the patent’s central subject
Manufacturing patent	Filling, sterilization, or production process	Not directly claimed
Regulatory exclusivity	FDA market exclusivity	Separate from patent term

Key Takeaways

US Patent 6,702,997 covers pediatric administration of benzalkonium-chloride-free, sterile, premixed, premeasured racemic albuterol sulfate nebulizer solution.
The principal claimed population is children 2 to 12 years old with asthma.
The broad dosage range is approximately 0.21 mg to 1.90 mg.
Dependent claims focus on approximately 0.75 mg and 1.50 mg doses.
The claims include single-dose packaging, 12-month therapeutic stability, and pediatric labeling limitations.
The patent is a method-of-treatment patent, not a broad albuterol composition patent.
Its US patent term expired in approximately April 2021.
Paragraph IV and Orange Book risks were historically relevant but do not create a current exclusion right under this patent.
Biosimilar analysis does not apply.
Current competition is governed primarily by FDA approval, manufacturing capability, device compatibility, formulation performance, and any separate unexpired patents.

FAQs

Does US Patent 6,702,997 cover all albuterol nebulizer solutions?

No. It covers only products and uses satisfying all material claim limitations, including pediatric asthma treatment, racemic albuterol sulfate, benzalkonium-chloride-free aqueous solution, single-dose packaging, and the claimed stability and dosage requirements.

Does the patent cover levalbuterol inhalation solution?

No. The claims recite racemic albuterol sulfate. Levalbuterol is a different active pharmaceutical ingredient and requires a separate patent and regulatory analysis.

Can a generic launch now infringe US Patent 6,702,997?

No current infringement liability arises from an expired US patent. A generic manufacturer must still assess other unexpired patents, FDA labeling requirements, and regulatory obligations.

Does pediatric labeling alone create infringement under the patent?

The patent combines labeling provisions with treatment and formulation limitations. Labeling alone would not satisfy the full claim. The complete product, proposed use, dosage, container, formulation, and stability profile must be assessed.

Is the 12-month stability limitation commercially significant?

Yes. A competing product would need to satisfy the claim’s therapeutic-stability requirement under the applicable claim construction and evidence. Stability data could become central in an infringement or validity dispute.

References

United States Patent and Trademark Office. (2004). U.S. Patent No. 6,702,997, Method for inducing bronchodilation in a child with asthma. U.S. Department of Commerce.
U.S. Food and Drug Administration. (n.d.). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/
U.S. Food and Drug Administration. (n.d.). AccuNeb (albuterol sulfate inhalation solution) prescribing information. FDA.
U.S. Congress. (2011). America Invents Act, Pub. L. No. 112-29, 125 Stat. 284.
U.S. Code, 35 U.S.C. §§ 154, 271(e)(2).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2002347948	⤷ Start Trial
Australia	2006202584	⤷ Start Trial
Australia	3297502	⤷ Start Trial
Canada	2464660	⤷ Start Trial
China	100413494	⤷ Start Trial
China	1720036	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,702,997

Summary for Patent: 6,702,997