US Patent 8,324,266: Scope, Claims, Expiration, and Patent Landscape
US Patent No. 8,324,266 is a Pearl Therapeutics inhalation patent directed to glycopyrrolate-containing metered-dose inhalers using a phospholipid-based "co-suspension" platform. Its claims combine formulation architecture, delivered-dose performance, pharmacodynamic outcomes, and combination therapy with LABA and corticosteroid agents.
The patent is commercially relevant to AstraZeneca's Pearl-derived respiratory portfolio, including Bevespi Aerosphere and related co-suspension inhaler programs. The strongest practical coverage is directed to a low-dose glycopyrrolate inhaler that delivers a substantially uniform aerosol over canister life and produces rapid, durable bronchodilation.
Based on the earliest claimed priority date reported in public patent records, the ordinary US patent term runs to approximately February 2027, subject to any patent-term adjustment, terminal disclaimer, or statutory correction reflected in the USPTO record. [1]
What does US Patent 8,324,266 protect?
The patent protects methods of treating respiratory disease, and methods of delivering at least two active agents, using a specific pressurized metered-dose inhaler formulation.
The core claimed combination has these elements:
| Claim element |
Technical requirement |
| Device |
Metered-dose inhaler with a canister |
| Propellant |
Pharmaceutically acceptable propellant free of additional constituents |
| First active agent |
Crystalline glycopyrrolate, or a pharmaceutically acceptable salt, ester, or isomer |
| Additional active agent |
LABA, ultra-LABA, short-acting beta agonist, corticosteroid, anti-inflammatory, antitussive, bronchodilator, or muscarinic antagonist |
| Suspending material |
Dry particulate phospholipid substantially insoluble in the propellant |
| Particle relationship |
Active particles associate with suspending particles to form a co-suspension |
| Mass ratio |
Suspending-particle mass exceeds active-particle mass; dependent claims specify approximately 10:1 to 200:1 |
| Delivery |
Glycopyrrolate dose generally no more than 150 micrograms per actuation in claim 1 |
| Clinical result |
At least 70 mL FEV1 improvement within 30 minutes or less, maintained for up to 12 hours or more |
| Uniformity |
Delivered-dose uniformity of plus or minus 25%, 30%, 20%, or 25%, depending on the claim |
| Aerosol performance |
Fine-particle fraction maintained within 80%, 90%, or 95% of its initial value throughout canister emptying |
The patent is therefore more specific than a conventional claim to "glycopyrrolate delivered by inhalation." It requires a particular formulation system and, in several claims, a defined clinical or aerosol-performance result.
How do the independent claims differ?
Claim 1: Disease-treatment claim
Claim 1 requires treatment of a pulmonary disease or disorder with a glycopyrrolate co-suspension inhaler. It is limited by:
- A phospholipid suspension system.
- Glycopyrrolate in crystalline form.
- At least one additional respiratory active agent.
- A greater mass of suspending particles than active particles.
- A glycopyrrolate dose of 150 micrograms or less per actuation.
- Rapid and sustained FEV1 improvement.
Claims 2 through 15 narrow claim 1 by adding disease, dose, performance, composition, ratio, and excipient limitations.
Claim 16: Respiratory-delivery claim
Claim 16 is structurally broader in one respect because it is not expressly limited to treatment of a named pulmonary disease. It covers respiratory delivery of at least two active agents from the co-suspension inhaler.
Its principal limitation is delivered-dose uniformity: each active agent must be delivered in respirable form at plus or minus 30% or better throughout emptying of the canister.
Claims 17 through 30 narrow this delivery claim by imposing tighter uniformity, fine-particle-fraction, particle-ratio, active-agent, dose, and clinical-response requirements.
The two independent claims create separate enforcement routes:
- Claim 1 focuses on treatment, glycopyrrolate dose, and FEV1 response.
- Claim 16 focuses on multi-agent respiratory delivery and uniformity over canister life.
A product that fails the clinical-response limitations of claim 1 could still implicate claim 16 if it satisfies the formulation and delivery-uniformity requirements.
Which dependent claims are most commercially significant?
Claims 4, 5, 13, and 14
These claims are closely aligned with low-dose glycopyrrolate/formoterol therapy for COPD.
Claim 13 requires:
- COPD or another listed respiratory disease;
- crystalline formoterol or related LABA;
- glycopyrrolate at 10 micrograms or less per actuation.
Claim 14 narrows the phospholipid-to-active-particle mass ratio to approximately 15:1 to 60:1 for COPD.
These limitations are commercially important because Bevespi Aerosphere delivers glycopyrrolate and formoterol in a low-dose pressurized metered-dose inhaler. The FDA-approved Bevespi dosage is two inhalations twice daily, with each actuation delivering glycopyrrolate 9 micrograms and formoterol fumarate 4.8 micrograms. [2]
Claims 8, 17, and 19 through 20
These claims focus on consistency during canister emptying.
The relevant thresholds are:
| Claim |
Required performance |
| Claim 8 |
Glycopyrrolate delivered-dose uniformity of plus or minus 25% or better |
| Claim 16 |
Each active agent at plus or minus 30% or better |
| Claim 17 |
Each active agent at plus or minus 20% or better |
| Claim 19 |
Fine-particle fraction within 90% of initial value |
| Claim 20 |
Fine-particle fraction within 95% of initial value |
These claims target a known technical problem in suspension inhalers: particle settling, aggregation, valve-metering variability, and changing aerosol performance as the canister approaches exhaustion.
Claims 21 and 22
Claim 21 specifies 1,2-distearoyl-sn-glycero-3-phosphocholine, commonly known as DSPC. Claim 22 specifies a suspending-particle-to-active-particle mass ratio of approximately 10:1 to 200:1.
DSPC is the key commercial formulation marker. A competing inhaler using a different insoluble phospholipid may avoid literal infringement of claim 21, but it could remain within the broader claims if the other limitations are met.
Claims 23 through 30
These claims extend the platform to:
- Crystalline LABAs;
- Formoterol;
- Formoterol crystalline solvates;
- Corticosteroids;
- Mometasone;
- Rapid FEV1 improvement;
- Clinically significant inspiratory-capacity improvement.
Claim 30 is particularly narrow because it requires formoterol and mometasone in crystalline form. It does not directly read on every triple therapy product. A product using budesonide instead of mometasone would not satisfy claim 30 as written, although broader claims or separate patents could be relevant.
What formulations are protected by US 8,324,266?
The patent covers a co-suspension rather than a conventional suspension containing only active drug particles in propellant.
The claimed structure contains:
- A propellant medium.
- Respirable active-agent particles.
- Respirable phospholipid particles.
- Association between the active-agent and phospholipid particles.
- A phospholipid mass that exceeds the active-agent mass.
The term "co-suspension" is central. It implies that active particles are carried or stabilized through association with larger or more abundant insoluble suspending particles. The claims do not merely require phospholipid as a dissolved surfactant or conventional formulation additive.
The phrase "propellant free of additional constituents" may narrow the claim depending on its construction. A formulation containing ethanol, cosolvent, dissolved surfactant, or another stabilizing constituent could create a noninfringement position if the limitation is construed literally. The specification and prosecution history would control whether "free of additional constituents" means no constituents beyond the propellant or no additional constituents material to the suspension system.
How does the patent cover Bevespi Aerosphere and related products?
Bevespi Aerosphere is the closest marketed product to the claim set because it combines:
- Glycopyrrolate;
- Formoterol fumarate;
- A pressurized metered-dose inhaler;
- A phospholipid-based co-suspension formulation;
- Low delivered doses;
- Long-acting bronchodilation for COPD.
The commercial product is not automatically infringed merely because it contains glycopyrrolate and formoterol. A claimant would need to establish each required limitation, including the relevant particle association, phospholipid composition, mass ratio, dose uniformity, aerosol performance, and, for claim 1, clinical response.
| Product or program |
Relationship to US 8,324,266 |
| Bevespi Aerosphere |
Closest marketed product profile; glycopyrrolate/formoterol co-suspension |
| Breztri Aerosphere |
Related Pearl/AstraZeneca co-suspension platform, but uses budesonide/formoterol/glycopyrrolate and must be assessed against each claim separately |
| Conventional dry-powder glycopyrrolate inhalers |
Generally outside the metered-dose co-suspension limitations |
| Nebulized glycopyrrolate |
Generally outside the claimed metered-dose inhaler architecture |
| Glycopyrrolate monotherapy MDI |
May avoid claims requiring at least two active agents |
| Non-phospholipid suspension MDI |
Potentially outside claims requiring dry particulate phospholipid |
The patent is a platform patent. Product-specific Orange Book patents, formulation patents, device patents, and dosing patents may provide separate protection even where US 8,324,266 does not read on the complete commercial product.
When does US Patent 8,324,266 lose exclusivity?
The expected ordinary expiration date is approximately February 2027, based on a February 2007 earliest priority date and the 20-year US patent-term rule. The exact enforceable expiration date must be determined from the USPTO patent-term data because patent-term adjustment can change the date. [1]
| Event |
Approximate timing |
| Earliest reported priority |
February 2007 |
| US patent grant |
November 27, 2012 |
| Ordinary 20-year term |
Approximately February 2027 |
| Potential post-expiration entry |
Subject to other unexpired patents, regulatory exclusivity, and litigation |
Patent expiration does not necessarily create immediate market freedom. A generic or follow-on inhaler may still face:
- Later-expiring formulation patents;
- Device patents;
- Valve or actuator patents;
- Method-of-use patents;
- Combination-product patents;
- Orange Book-listed patents for the reference product;
- Manufacturing and pharmaceutical-process patents.
What is the Orange Book status of US 8,324,266?
US 8,324,266 should not be treated as an Orange Book barrier without confirming the current FDA-listed patent numbers for the relevant reference product.
FDA Orange Book listings are product-specific. A patent may protect a formulation technology used in a product without being listed for every product that uses the same platform. Conversely, a product may have later-issued patents that are more important to generic-entry timing than the earlier platform patent. [3]
For Bevespi Aerosphere and Breztri Aerosphere, the relevant Orange Book analysis should separate:
- Active-ingredient patents;
- Formulation patents;
- Device and actuator patents;
- Method-of-use patents;
- Patents covering the specific glycopyrrolate/LABA or triple combination;
- Pediatric-exclusivity effects;
- Patent delisting or expiration updates.
The practical conclusion is that US 8,324,266 is best viewed as an early platform patent, not as the sole determinant of generic entry.
Which companies are challenging the patent?
A Paragraph IV challenge must be evaluated against the patents listed for a specific reference drug and ANDA, not against a patent in isolation.
Publicly reported generic activity for glycopyrrolate/formoterol inhalers has focused on the broader Bevespi patent estate rather than establishing that US 8,324,266 alone is the only asserted patent. A generic applicant could challenge the patent on several grounds:
- Lack of written description for the full active-agent genus;
- Lack of enablement across all claimed diseases, doses, LABAs, corticosteroids, and aerosol outcomes;
- Obviousness over earlier phospholipid suspension inhalers combined with known glycopyrrolate or formoterol products;
- Indefiniteness of "clinically significant increase";
- Indefiniteness or scope problems involving "up to 12 hours or more";
- Failure to meet the claimed performance results;
- Noninfringement based on propellant composition, particle association, or excipient selection.
No final invalidity judgment or broad license affecting the patent is established by the claim text alone. Hatch-Waxman litigation and settlement terms must be checked against the relevant FDA ANDA litigation records and court dockets. [3,4]
How strong is the patent estate?
Strengths
The patent has several commercially useful limitations:
- It claims the co-suspension architecture at the method-of-use level.
- It links the formulation to measurable delivery performance.
- It covers low-dose glycopyrrolate/formoterol use.
- It addresses dose uniformity throughout canister emptying.
- It includes narrower DSPC and particle-ratio claims.
- It covers multi-agent and potential triple-agent formulations.
The performance limitations can make design-around more difficult if a competing product uses the same formulation architecture and achieves comparable aerosol consistency.
Weaknesses
The claim set also presents validity and enforcement risks:
- Several claims depend on clinical outcomes that may require substantial clinical evidence.
- "Clinically significant" is potentially fact-sensitive and indefinite without objective criteria.
- Claim 1 includes a broad list of respiratory diseases and additional active-agent categories.
- Claims 1 and 16 use broad chemical classes while requiring crystalline particles and specific performance.
- The "free of additional constituents" limitation may create a narrow construction.
- The claims may require proof of formulation properties that are not visible from the product label.
- The claim text contains apparent drafting anomalies, including claim 23's "second species ofb" language and claim 24's "crystallinesolvate" wording. These errors may be correctable or interpreted in context, but they should be reviewed in the issued patent, certificate of correction, and prosecution history.
Overall, the patent is strongest against a product that copies the Pearl co-suspension design and delivers glycopyrrolate/formoterol in a low-dose MDI. It is weaker against a product that changes the suspending material, propellant system, particle-association mechanism, delivery device, or active-agent combination.
What generic launch risks exist?
At patent expiration
A generic applicant could pursue an ANDA with a Paragraph IV certification against unexpired Orange Book patents. If US 8,324,266 is the only relevant blocking patent, its approximately 2027 expiration would establish a potential launch date, subject to regulatory approval and other patents.
Before patent expiration
Potential launch routes include:
- A noninfringing formulation using a different phospholipid.
- A propellant system containing additional constituents.
- A device or valve configuration that avoids the claimed co-suspension.
- A product with a different active-agent combination.
- A dose or performance profile outside the claims.
- A declaratory-judgment or Hatch-Waxman invalidity strategy.
- A settlement with a licensed or authorized generic arrangement.
The highest-risk design-around issue is whether the competitor's active particles associate with insoluble phospholipid suspending particles. The formulation may avoid claim 21 by using a different phospholipid yet remain exposed under claims 1, 10, 16, 18, or 22.
What licensing deals affect the patent?
Pearl Therapeutics developed the co-suspension technology and was acquired by AstraZeneca in 2013. AstraZeneca reported an agreement to acquire Pearl for an upfront payment of approximately $560 million, with potential additional consideration that could bring the total transaction value to approximately $1.15 billion. [5]
The acquisition transferred Pearl's inhaled respiratory assets and associated intellectual-property portfolio to AstraZeneca. Any freedom-to-operate or licensing review should therefore treat AstraZeneca as the principal commercial successor to Pearl's relevant patent assets, while checking assignment records for the particular patent family.
Key Takeaways
- US 8,324,266 is a co-suspension inhaler patent centered on crystalline glycopyrrolate, phospholipid suspending particles, and metered-dose delivery.
- Claims 1 and 16 are the principal independent claims.
- Claim 13 is particularly relevant to low-dose glycopyrrolate/formoterol COPD therapy.
- DSPC and phospholipid-to-active-particle ratios are important narrowing limitations.
- The patent is closely related to Pearl Therapeutics' Aerosphere platform and is commercially relevant to Bevespi.
- The expected ordinary patent-term endpoint is approximately February 2027, subject to USPTO term data.
- Orange Book status must be analyzed by reference product; this patent should not be assumed to be the only relevant barrier.
- Key validity risks include obviousness, enablement, written description, indefiniteness, and proof of formulation performance.
- Generic risk is highest for a copied glycopyrrolate/LABA co-suspension MDI and lower for products using a different propellant, phospholipid, device, or delivery architecture.
- AstraZeneca acquired Pearl Therapeutics and its respiratory patent portfolio in 2013.
FAQs
Does US 8,324,266 cover glycopyrrolate alone?
Generally no. The principal claims require one or more additional active agents, although the permitted additional agents are defined broadly.
Does the patent cover dry-powder inhalers?
Generally no. The independent claims require a metered-dose inhaler with a canister containing a propellant-based co-suspension.
Does use of DSPC automatically create infringement?
No. DSPC is a limitation in claim 9 and claim 21. Other claims cover broader phospholipid systems, while infringement also requires satisfaction of every limitation in the asserted claim.
Does the patent cover budesonide/glycopyrrolate/formoterol?
Potentially, depending on the asserted claim. Claims requiring mometasone do not literally cover budesonide, but broader claims may cover a LABA/corticosteroid/glycopyrrolate co-suspension if all other limitations are met.
Can a generic launch immediately when the patent expires?
No. Launch also depends on FDA approval, Orange Book-listed patents, other unexpired AstraZeneca patents, regulatory exclusivity, and any Hatch-Waxman litigation or settlement restrictions.
References
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United States Patent and Trademark Office. (2012). US Patent No. 8,324,266, Pharmaceutical compositions and methods of use. USPTO Patent Center and patent grant record.
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U.S. Food and Drug Administration. (2024). Bevespi Aerosphere prescribing information. AstraZeneca Pharmaceuticals LP.
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U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA.
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U.S. Courts. (2025). Patent litigation and Hatch-Waxman case records. PACER and federal district court docket records.
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AstraZeneca. (2013). AstraZeneca to acquire Pearl Therapeutics. AstraZeneca corporate announcement.
