Teva v. Armstrong & Amphastar: ProAir HFA Inhaler Patents Dismissed With Prejudice
Teva Branded Pharmaceutical Products and affiliates sued Armstrong Pharmaceuticals and Amphastar Pharmaceuticals for infringement of three patents covering the ProAir HFA albuterol sulfate inhalation aerosol. The Delaware District Court entered a consent dismissal with prejudice after 201 days, with each party bearing its own costs.
A consent exit: Teva and Amphastar settle ProAir inhaler patent fight
On July 25, 2024, Teva Branded Pharmaceutical Products R&D LLC, Teva Pharmaceuticals USA Inc., and Norton (Waterford) Limited filed a patent infringement action in the District of Delaware against Armstrong Pharmaceuticals Inc. and its parent Amphastar Pharmaceuticals Inc. The suit centred on three U.S. patents — US10561808B2, US9463289B2, and US9808587B2 — asserted to cover the ProAir HFA (albuterol sulfate) Inhalation Aerosol, 90 mcg per actuation, a widely used short-acting bronchodilator for asthma and COPD management.
The litigation concluded on February 11, 2025, when Judge Maryellen Noreika entered a Consent Order of Dismissal with prejudice on joint application of all parties. The order extinguishes all claims, defenses, and counterclaims in Civil Action No. 24-0869, and directs each side to bear its own legal costs. A dismissal with prejudice forecloses Teva from re-filing the same infringement claims against Armstrong and Amphastar on these patents — a meaningful concession by the patent holder, though the terms that produced the consent remain confidential.
The 201-day resolution is notably swift for a multi-patent pharmaceutical infringement case in Delaware, suggesting the parties reached a private commercial arrangement — possibly a licensing agreement, an agreed market-entry date, or a settlement structured around the 30-month Hatch-Waxman stay — rather than litigating to judgment. The public record does not disclose the underlying business terms, so the precise commercial outcome for each side is unknown. What is clear is that the mutual cost-bearing provision and the brevity of litigation are consistent with a negotiated resolution that both sides found acceptable.
Filing to Consent Judgment in 201 days
201 days — resolved well under the typical 2–3 year ANDA patent trial cycle in Delaware
Consent dismissal with prejudice: what the order means for both parties
Dismissal with prejudice bars re-filing on these patents
A dismissal with prejudice entered by consent order is a final adjudication on the merits for procedural purposes. Teva cannot refile the same infringement claims against Armstrong or Amphastar on US10561808B2, US9463289B2, or US9808587B2 in respect of the accused conduct. However, the patents themselves remain valid and enforceable against other third parties — the bar is claim-specific and party-specific, not a ruling on patent validity.
Res judicata applies — no re-filingTeva surrenders its infringement claim, but not its patent rights
By agreeing to dismissal with prejudice, Teva forfeits its right to pursue these particular infringement claims against Armstrong and Amphastar on the three asserted patents. In practice, this typically reflects a negotiated commercial resolution — such as a licensing arrangement or an agreed entry date — rather than a concession that infringement did not occur. Teva retains full ability to enforce the same patents against other generic entrants, and the patents’ validity is unaffected by this order.
Patents survive — enforcement right retained vs. othersAmphastar gains certainty — litigation risk eliminated
Armstrong and Amphastar exit the case without a finding of infringement against them and without an invalidity ruling in their favour. The with-prejudice dismissal ensures Teva cannot resurrect these specific claims, giving Amphastar commercial certainty for its albuterol product plans. The equal cost-bearing provision suggests neither side extracted a decisive litigation advantage, consistent with a mutual settlement rather than a capitulation by either party.
No infringement finding — certainty achievedNegotiated resolution leaves ProAir’s competitive landscape open
The rapid settlement — 201 days from filing — suggests Amphastar’s ANDA path to market was likely resolved through a private agreement, possibly including a licensed entry date or royalty arrangement. For other generic manufacturers eyeing ProAir HFA, Teva’s three patents remain live enforcement tools. The absence of any invalidity determination means these patents have not been tested on their merits, preserving Teva’s freedom to assert them in future Hatch-Waxman proceedings against subsequent ANDA filers.
Patent landscape unchanged for future challengersFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Teva Branded Pharmaceutical Products R&D LLC | Company | Pharmaceutical IP holder — branded inhaler developer, holder of US10561808B2 and related patentsSearch in Eureka ↗ |
| Co-Plaintiff | Teva Pharmaceuticals USA, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | Norton (Waterford) Limited | Individual | Search in Eureka ↗ |
| Defendant | Armstrong Pharmaceuticals, Inc. | Company | Armstrong Pharmaceuticals (subsidiary of Amphastar) — generic pharmaceutical ANDA filerSearch in Eureka ↗ |
| Co-Defendant | Amphastar Pharmaceuticals, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Annaka Nava | Attorney | Counsel for Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Plaintiff counsel | Daryl L. Wiesen | Attorney | Counsel for Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Plaintiff counsel | Karen Elizabeth Keller | Attorney | Counsel for Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Plaintiff counsel | Louis L. Lobel | Attorney | Counsel for Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Plaintiff counsel | Nathan Roger Hoeschen | Attorney | Counsel for Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Plaintiff counsel | Thomas V. McTigue , IV | Attorney | Counsel for Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Plaintiff law firm | Shaw Keller LLP | Law Firm | Representing Teva Branded Pharmaceutical Products R&D LLCSearch in Eureka ↗ |
| Defendant counsel | Aaron E. Schindler | Attorney | Counsel for Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Christine Dealy Haynes | Attorney | Counsel for Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Emily J. Greb | Attorney | Counsel for Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Frederick L. Cottrell , III | Attorney | Counsel for Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Jason James Rawnsley | Attorney | Counsel for Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Matthew A. Lembo | Attorney | Counsel for Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant law firm | Richards Layton & Finger PA | Law Firm | Representing Armstrong Pharmaceuticals, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Maryellen Noreika | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The consent order language — ‘all claims, defenses, and counterclaims … dismissed, with prejudice’ — is comprehensive and symmetrical: Teva’s infringement claims and Armstrong’s invalidity or non-infringement counterclaims are extinguished simultaneously. The equal cost-bearing clause reinforces the mutual character of the resolution. Critically, the order contains no admission of infringement, no validity ruling, and no injunctive terms, meaning the court made no substantive determination on the merits of any party’s position. The three asserted patents remain intact for enforcement against other defendants.
US10561808B2, US9463289B2 & US9808587B2 — ProAir HFA albuterol inhaler patents
The three patents at issue — US10561808B2, US9463289B2, and US9808587B2 — cover technology underlying ProAir HFA (albuterol sulfate) Inhalation Aerosol, 90 mcg per actuation, a short-acting beta-2 agonist bronchodilator delivered via pressurised metered-dose inhaler (pMDI). Originating from applications filed across multiple years (application numbers US15/262818, US14/103324, and US15/269249), the patents likely protect aspects of the inhaler device, formulation, or delivery mechanism. All three are assigned to the Teva/Norton group, consistent with the co-plaintiff structure.
ProAir HFA is a high-volume branded rescue inhaler in the U.S. asthma market, making its patent estate a critical commercial asset. Generic entry — typically via an ANDA with a Paragraph IV certification — would directly erode branded revenue. The fact that Teva deployed three overlapping patents in a single suit suggests a layered enforcement strategy designed to raise the cost and uncertainty for any generic challenger. With no invalidity ruling emerging from this case, each patent retains its presumption of validity, presenting a meaningful FTO and litigation risk for subsequent ANDA filers targeting the same product.
Should you run an FTO against US10561808B2, US9463289B2 & US9808587B2?
Any pharmaceutical company developing or commercialising a generic albuterol sulfate metered-dose inhaler product targeting the U.S. market should treat these three Teva patents as live enforcement risks. This case confirms Teva’s willingness to assert all three patents simultaneously in Delaware — and that none have been adjudicated invalid or not infringed. ANDA filers, device manufacturers sourcing pMDI components, and contract manufacturers should conduct a structured FTO analysis before filing or launching.
PatSnap Eureka’s FTO Search Agent enables R&D and regulatory teams to map claim scope across US10561808B2, US9463289B2, and US9808587B2, identify prior art relevant to validity challenges, and surface related patent family members that may extend protection beyond the asserted patents. Eureka’s litigation overlay also flags enforcement history, helping teams assess how aggressively a portfolio is being monetised before committing to an ANDA strategy.
Run a freedom-to-operate analysis on US10561808B2 to assess your product’s exposure
Run FTO in Eureka →Similar Hatch-Waxman inhaler patent cases in Delaware District Court
Explore related pharmaceutical patent infringement actions involving branded metered-dose inhalers and ANDA challenges in the District of Delaware.
What this case signals for the branded inhaler IP landscape
A swift consent exit in a three-patent inhaler suit raises important questions for any ANDA filer or branded player in the albuterol space.
Speed of settlement signals commercial leverage, not legal weakness
Resolving a three-patent pharmaceutical infringement suit in Delaware in under seven months — without trial or claim construction — strongly suggests a licensing or market-entry agreement was reached early. ANDA filers in adjacent inhaler categories should treat this as a signal that Teva is willing to negotiate structured market access rather than litigate to verdict.
Three uncontested patents strengthen Teva’s enforcement posture for future challengers
Because no invalidity or non-infringement ruling was issued, US10561808B2, US9463289B2, and US9808587B2 emerge from this case without any adverse finding. Any subsequent ANDA filer targeting ProAir HFA faces these patents at full strength, with no prior art arguments or claim construction positions available from this docket to build on.
Teva v Armstrong — key questions answered
The case was dismissed with prejudice by consent order on February 11, 2025. Teva, Armstrong, and Amphastar jointly applied for the dismissal, extinguishing all claims, defenses, and counterclaims. Each party was ordered to bear its own costs. No merits ruling on infringement or patent validity was issued.
Teva asserted three U.S. patents: US10561808B2 (application US15/262818), US9463289B2 (application US14/103324), and US9808587B2 (application US15/269249). All three relate to the ProAir HFA albuterol sulfate inhalation aerosol, 90 mcg per actuation.
A dismissal with prejudice is a final disposition that bars Teva from re-filing the same infringement claims against Armstrong and Amphastar on the three asserted patents. However, the patents remain valid and enforceable against other parties. No invalidity or non-infringement finding was made, so third-party challengers cannot rely on this case to attack the patents.
The public record does not disclose the settlement terms. However, resolution in under seven months — before claim construction — is consistent with a negotiated commercial arrangement, potentially including a licensing deal or an agreed ANDA market-entry date structured around the Hatch-Waxman 30-month stay. The equal cost-bearing provision suggests a mutual resolution rather than a one-sided capitulation.
Plaintiffs are Teva Branded Pharmaceutical Products R&D LLC, Teva Pharmaceuticals USA Inc., and Norton (Waterford) Limited — collectively the Teva group, holding the ProAir HFA patent portfolio. Defendants are Armstrong Pharmaceuticals Inc. and its parent Amphastar Pharmaceuticals Inc., a generic pharmaceutical company that had apparently filed an ANDA seeking to market a generic version of ProAir HFA.
PatSnap Eureka searches patents and litigation data to answer instantly.