United States Drug Patent 6,887,459: Claims, Scope, Expiration, and Formoterol Patent Landscape

U.S. Patent No. 6,887,459 protects a narrow inhaled dry-powder method for treating chronic obstructive pulmonary disease with formoterol as the sole active ingredient. The claims target a specific formulation architecture: formoterol fumarate dihydrate, a relatively coarse carrier, and a carrier-to-drug ratio generally corresponding to a 12-microgram formoterol dose mixed with approximately 20 to 25 milligrams of carrier. The patent’s nominal U.S. term expired in 2021, subject to any recorded patent-term adjustment or extension.

What does U.S. Patent 6,887,459 cover?

The patent covers treating COPD by administering an inhaled dry powder containing:

Formoterol or a pharmaceutically acceptable salt or solvate;
A pharmaceutically acceptable particulate diluent or carrier;
A carrier-to-formoterol ratio of 400:1 to 5,000:1 by weight;
A carrier median particle diameter of 40 to 100 micrometers; and
Formoterol as the only active ingredient, either expressly or through the claimed composition structure.

The patent is directed to a method of treatment, not merely to a pharmaceutical composition or inhaler device. A product would therefore need to be used for the claimed COPD indication, or marketed in a manner that supports method-of-use infringement, for the claim set to have practical relevance.

Core claim limitations

Limitation	Claims affected	Scope
COPD treatment	1, 3-10	The disease indication is mandatory
Administration by inhalation	1, 3-10	Oral, injectable, nebulized, or non-inhaled use is outside the literal claim
Dry powder	1, 3-10	Liquid formulations are excluded
Formoterol	1-10	Formoterol must be the therapeutic active
Formoterol fumarate dihydrate	2-10, with claim-specific variations	The preferred and commercially relevant salt form
Carrier ratio of 400 to 5,000 micrograms per microgram of formoterol	1-10	A key quantitative limitation
Carrier median particle diameter of 40 to 100 micrometers	1-10	A second key quantitative limitation
Formoterol as sole active ingredient	Claim 1 expressly; claims 3-10 through composition language	Combination products are generally outside the literal scope
Lactose carrier	Claim 5	Narrower dependent claim
Carrier ratio of 800:1 to 3,000:1	Claim 6	Preferred subrange
Formoterol particle diameter up to 10 micrometers	Claim 7	Micronized drug requirement
Capsule containing a unit dose	Claims 8 and 9	Capsule-based inhaler products
12 micrograms formoterol and 19,988 to 24,988 micrograms carrier	Claim 9	Highly specific unit-dose configuration
Reservoir multidose inhaler	Claim 10	Device presentation is different from the capsule claims

[Source: U.S. Patent No. 6,887,459, claims 1-10.]

How broad is claim 1 of U.S. Patent 6,887,459?

Claim 1 is the broadest independent claim, but its cumulative limitations make it narrower than a general formoterol COPD claim.

A potentially infringing product or use must satisfy each of the following elements:

The patient has COPD.
The product is administered by inhalation.
The administered material is a dry powder.
Formoterol is present as the active drug.
The carrier is present at 400 to 5,000 micrograms per microgram of formoterol.
The carrier has a median particle diameter of 40 to 100 micrometers.
Formoterol is the only active ingredient.
The dose is effective for treating COPD.

The claim does not require a particular inhaler brand, capsule material, manufacturing process, particle-size distribution for the formoterol, or specific clinical dose. Those features enter through dependent claims or the specification.

Meaning of “consisting essentially of”

Claim 1 uses “consisting essentially of” in describing the dry powder. This language generally permits components that do not materially affect the basic and novel characteristics of the claimed formulation, while excluding additional components that materially alter those characteristics.

The principal legal issue is whether an added excipient, processing aid, stabilizer, lubricant, or other ingredient changes the formulation’s relevant performance. A composition containing formoterol and lactose may remain within the claim despite minor conventional excipients. A formulation containing another bronchodilator or inhaled corticosteroid is materially different and is unlikely to satisfy claim 1.

The phrase does not eliminate the requirement that formoterol be the only active ingredient. A formoterol-glycopyrronium, formoterol-budesonide, or formoterol-beclometasone product would face a strong non-infringement position under the literal “only active ingredient” limitation.

What do claims 3 through 10 add?

Claims 3 through 10 define narrower embodiments of the dry powder method.

Claim 3: formoterol fumarate dihydrate

Claim 3 requires a dry powder consisting of, or consisting essentially of, formoterol fumarate dihydrate and the carrier. It is narrower than claim 1 because it does not cover every pharmaceutically acceptable form of formoterol.

The claim also recites the same broad carrier ratio of 400 to 5,000 micrograms per microgram and the same carrier particle-size range of 40 to 100 micrometers.

Claims 4 and 5: carrier chemistry

Claim 4 limits the carrier to a saccharide, sugar alcohol, or mixture. Claim 5 narrows this further to lactose.

Lactose is the commercially important carrier for many capsule-based dry-powder inhalers. The claim does not require a particular lactose grade, supplier, crystallinity, or lactose particle-size distribution beyond the 40-to-100-micrometer median diameter requirement.

Claim 6: preferred carrier ratio

Claim 6 limits the ratio to 800 to 3,000 micrograms of carrier per microgram of formoterol.

For a 12-microgram formoterol dose, this corresponds to:

Carrier ratio	Approximate carrier mass for 12 micrograms formoterol
800:1	9.6 mg
3,000:1	36.0 mg
Claim 9 range	19.988 to 24.988 mg

Claim 9’s carrier amount corresponds to approximately 1,666 to 2,082 micrograms of carrier per microgram of formoterol. It therefore falls within claim 6’s 800-to-3,000 range.

Claim 7: micronized formoterol

Claim 7 requires the formoterol particle mean diameter to be no more than 10 micrometers. This limitation is consistent with the use of micronized drug particles in dry-powder inhalation, where aerodynamic performance and dispersibility depend on the interaction between fine active particles and larger carrier particles.

The claim recites mean particle diameter, while the carrier limitation recites median particle diameter. Those are different statistical descriptors. A design-around analysis must use the measurement method and particle-size data applicable to each claimed term.

Claims 8 and 9: capsule products

Claim 8 covers a capsule containing a unit dose of formoterol. Claim 9 specifies:

12 micrograms of formoterol; and
19,988 to 24,988 micrograms of carrier.

This formulation profile is closely associated with capsule-based formoterol inhalers that use a unit-dose capsule and a dedicated inhalation device.

A capsule containing 12 micrograms of formoterol fumarate dihydrate and approximately 20 to 25 milligrams of lactose would present the greatest claim-overlap risk if the patent were enforceable and the remaining particle-size limitations were met.

Claim 10: reservoir inhalers

Claim 10 covers a dry powder held in a reservoir of a multidose powder inhaler adapted to deliver a unit dose per actuation.

The claim is structurally separate from the capsule claims. A reservoir inhaler does not need to use a capsule, but it must satisfy the formulation, particle-size, COPD-treatment, and formoterol limitations incorporated from claim 3.

What formulations are protected by U.S. Patent 6,887,459?

The strongest formulation coverage is directed to a single-active-ingredient formoterol fumarate dihydrate powder blended with coarse lactose or another saccharide carrier.

Formulation	Likely claim position
Formoterol fumarate dihydrate plus lactose, 12 micrograms drug and approximately 20-25 mg lactose	Strong overlap with claims 3, 5, 6, 8, and 9 if particle-size requirements are met
Formoterol fumarate dihydrate plus lactose in a multidose reservoir inhaler	Potential overlap with claims 3, 5, 6, 7, and 10
Formoterol fumarate dihydrate plus carrier outside the 40-100 micrometer range	Potential non-infringement based on carrier particle size
Formoterol dose with carrier below 400:1 or above 5,000:1	Outside the express ratio limitation
Formoterol combined with an inhaled corticosteroid	Generally outside the sole-active-ingredient requirement
Formoterol combined with another bronchodilator	Generally outside the sole-active-ingredient requirement
Nebulized formoterol solution	Outside the dry-powder and inhalation-powder limitations
Formoterol metered-dose aerosol	Outside the dry-powder limitation
Formoterol fumarate without the dihydrate form	Potentially outside claims 2-10, but claim 1 may require separate analysis

When did U.S. Patent 6,887,459 lose exclusivity?

The patent’s nominal term ran for 20 years from the relevant nonprovisional filing date. The patent was granted on May 24, 2005, and its underlying priority and filing history trace to the early 2000s. On that basis, the ordinary U.S. patent term expired in 2021, subject to any patent-term adjustment shown in the USPTO record.

A patent-term adjustment can extend the calculated expiration date for USPTO examination delays. Patent-term extension under 35 U.S.C. § 156 is a separate mechanism generally associated with regulatory review of an approved product. The enforceability analysis should therefore use the expiration date recorded for the issued patent and any certificate affecting term. [U.S. Patent and Trademark Office, n.d.; 35 U.S.C. §§ 154, 156.]

As a practical matter, U.S. Patent 6,887,459 is no longer a live blocking patent for new U.S. generic or branded dry-powder formoterol development if its recorded term ended in 2021. Its historical significance remains relevant to earlier ANDA certifications, settlement analysis, and the interpretation of the Foradil product patent estate.

What was the FDA and Orange Book relevance?

The patent was commercially relevant to inhaled formoterol products, particularly capsule-based dry-powder products such as Foradil Aerolizer. Foradil contains formoterol fumarate and is administered through a dry-powder inhaler. The FDA-approved product information identifies the 12-microgram capsule presentation and the inhalation route. [U.S. Food and Drug Administration, 2010.]

The key regulatory distinction is between:

Patents listed in the FDA Orange Book for an approved drug product;
Patents that cover the formulation or device;
Method-of-use patents listed for an approved indication; and
Unlisted patents that may still be enforceable but do not create an automatic ANDA stay.

An Orange Book-listed patent can support a Paragraph IV certification and, if timely litigated, a 30-month stay of approval under the Hatch-Waxman framework. The listing does not itself establish infringement or validity. The patent must still be tested against the proposed ANDA product and labeling. [FDA, 2024; 21 U.S.C. § 355(j).]

For a dry-powder formoterol ANDA, the most relevant questions would have been whether the proposed product:

Used formoterol fumarate dihydrate;
Delivered 12 micrograms per actuation or capsule;
Used approximately 20 to 25 milligrams of lactose;
Had a carrier median particle diameter of 40 to 100 micrometers;
Used a capsule or reservoir device; and
Carried COPD treatment language in the proposed labeling.

Which products and competitors are most relevant?

Foradil Aerolizer

Foradil Aerolizer is the closest commercial reference product to claims 8 and 9 because it uses a unit-dose capsule containing formoterol fumarate and a dry-powder inhaler. Its 12-microgram presentation aligns closely with the numerical limitation in claim 9.

Oxis and other formoterol dry powders

Other formoterol dry-powder products, including products marketed outside the United States, may implicate the same formulation concepts. Their claim exposure depends on carrier particle size, drug-to-carrier ratio, device configuration, and approved indication.

Symbicort and other combination products

Formoterol-containing combination products generally present less direct literal exposure because the patent claims require formoterol to be the only active ingredient. Symbicort, for example, contains budesonide and formoterol. A combination formulation may still require review of other patents, but U.S. Patent 6,887,459 is not a strong literal claim against the combination itself.

Nebulized formoterol

Nebulized formoterol products use a liquid dosage form rather than the claimed dry powder. They fall outside the central formulation architecture of the patent.

How strong is the patent estate for formoterol dry-powder products?

The patent was commercially meaningful during its term but technically narrow. Its strength came from the combination of multiple measurable parameters:

A defined COPD method of treatment;
A dry-powder route;
Formoterol as the sole active;
A high carrier-to-drug ratio;
Coarse carrier particles;
A specific formoterol salt in dependent claims;
Capsule and reservoir delivery configurations.

Its weaknesses included the limited therapeutic scope, the need to prove several formulation parameters, and possible invalidity challenges based on prior art involving formoterol dry powders, lactose carriers, micronized drug particles, and inhaler capsules.

Potential Paragraph IV positions

A generic applicant could have developed several non-infringement positions:

Use a carrier median diameter below 40 micrometers or above 100 micrometers.
Use a carrier-to-formoterol ratio outside the claimed range.
Use a different active form where only the fumarate dihydrate claims are asserted.
Use a liquid nebulized formulation.
Use a combination product with a second active ingredient.
Remove COPD treatment language from the proposed labeling, where legally permissible.
Use a device and formulation that do not satisfy the capsule or reservoir limitations.

Validity arguments could focus on anticipation or obviousness from earlier formoterol inhalation products, known lactose carrier systems, and routine particle-size optimization. The quantitative ranges may have been defended through formulation performance data, but the claims remain vulnerable if prior art disclosed overlapping ranges or a predictable selection within them.

What generic entry risks exist today?

The patent itself does not create a current U.S. generic-entry barrier after expiration. Current commercial risk would instead arise from:

Other expired or unexpired formulation patents;
Device patents;
Manufacturing patents;
Labeling and regulatory exclusivity;
Trade-secret controls over particle engineering and inhaler filling;
Product-specific patents listed for the relevant NDA;
State or federal litigation unrelated to this patent.

There is no biosimilar pathway issue because formoterol is a small-molecule active ingredient. The relevant regulatory pathway is an ANDA or, depending on the product, a 505(b)(2) application. FDA approval would depend on pharmaceutical equivalence, bioequivalence or comparative performance, device compatibility, labeling, and manufacturing controls.

What geographic coverage did the patent have?

U.S. Patent 6,887,459 provided protection only in the United States. Related applications or counterpart patents could have existed in Europe and other jurisdictions, but those rights required separate review by country.

The principal geographic business implications were:

U.S. expiry did not determine European or Asian expiry;
Formoterol salt, formulation, and inhaler patents could have different family members;
Regulatory exclusivity and patent linkage varied by jurisdiction;
A U.S. freedom-to-operate conclusion could not be exported to other markets.

What manufacturing and intellectual-property barriers remain?

After patent expiry, technical barriers can remain even when legal exclusivity has ended. A competing manufacturer must control:

Micronization of formoterol;
Uniform blending with lactose or another carrier;
Segregation prevention during storage and handling;
Capsule fill weight and content uniformity;
Aerodynamic particle-size distribution;
Dose emission and delivered-dose consistency;
Reservoir metering accuracy;
Moisture control;
Inhaler resistance and device performance.

These manufacturing controls do not extend the patent term. They can, however, affect development cost, approval timing, product quality, and commercial launch risk.

Key Takeaways

U.S. Patent 6,887,459 claims inhaled dry-powder treatment of COPD with formoterol as the sole active ingredient.
The critical technical limitations are a 400:1 to 5,000:1 carrier ratio and a carrier median particle diameter of 40 to 100 micrometers.
Claim 9 is especially narrow and closely tracks a 12-microgram capsule formulation containing approximately 20 to 25 milligrams of carrier.
Lactose-containing formoterol fumarate dihydrate powders are the most relevant historical embodiments.
Combination products containing formoterol plus another active ingredient generally fall outside the literal sole-active-ingredient requirement.
Nebulized liquids and non-powder aerosols are outside the central claim structure.
The patent’s nominal U.S. term expired in 2021, subject to the official USPTO term record.
Current U.S. generic-entry risk must be assessed against other product, device, formulation, manufacturing, and method-of-use rights.

FAQs

Does U.S. Patent 6,887,459 cover Symbicort?

Generally, no. Symbicort contains budesonide and formoterol, while the patent claims require formoterol to be the only active ingredient.

Does the patent cover a formoterol dry powder with a carrier other than lactose?

Yes, the broader claims cover a pharmaceutically acceptable particulate carrier. Lactose is required only by claim 5 and related dependent-claim analysis.

Is a 12-microgram formoterol capsule automatically covered?

No. The formulation must also satisfy the carrier quantity, carrier median particle diameter, dry-powder, COPD-treatment, and other applicable limitations.

Can a formoterol nebulizer infringe this patent?

A liquid nebulized formulation would generally fall outside the dry-powder limitations recited in the claims.

Does patent expiration eliminate all freedom-to-operate risk for generic formoterol inhalers?

No. Expiration of this patent removes its own blocking effect, but other patents, device rights, manufacturing patents, regulatory exclusivities, and labeling constraints may remain relevant.

References

U.S. Patent No. 6,887,459. (2005). Use of formoterol for the treatment of chronic obstructive pulmonary disease. U.S. Patent and Trademark Office.
U.S. Food and Drug Administration. (2010). Foradil Aerolizer: Prescribing information. U.S. Department of Health and Human Services.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
U.S. Patent and Trademark Office. (n.d.). Patent term adjustment and patent term extension. U.S. Department of Commerce.
21 U.S.C. § 355(j).
35 U.S.C. §§ 154, 156.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	9928311	Nov 30, 1999

PCT Information
PCT Filed	November 28, 2000	PCT Application Number:	PCT/EP00/11894
PCT Publication Date:	June 07, 2001	PCT Publication Number:	WO01/39745

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2837401	⤷ Start Trial
Australia	769765	⤷ Start Trial
Brazil	0015908	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,887,459

Summary for Patent: 6,887,459