DCT

1:25-cv-01139

Azurity Pharma Inc v. Annora Pharma Pvt Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-01139, D. Del., 09/12/2025
  • Venue Allegations: Venue is alleged to be proper because the Defendant is a foreign corporation not residing in any U.S. judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s filing of an Abbreviated New Drug Application (ANDA) for a generic amlodipine benzoate oral suspension infringes seven patents related to stable liquid pharmaceutical formulations.
  • Technical Context: The dispute concerns formulations of amlodipine, a widely used calcium channel blocker for hypertension, and specifically addresses the challenges of creating stable, accurately dosed oral liquid versions for patients who cannot swallow tablets.
  • Key Procedural History: The complaint notes prior litigation between the parties concerning different ANDA products, highlighting disputes over the terms of confidential access to ANDA materials, which may provide context for the Plaintiff’s decision to file this suit promptly without extended pre-suit negotiation.

Case Timeline

Date Event
2016-10-07 Priority Date for ’461 and ’984 Patents
2018-04-11 Priority Date for ’453, ’409, ’498, ’326, and ’685 Patents
2020-10-13 U.S. Patent No. 10,799,453 Issues
2022-10-18 U.S. Patent No. 11,471,409 Issues
2022-11-01 U.S. Patent No. 11,484,498 Issues
2023-07-18 U.S. Patent No. 11,701,326 Issues
2024-03-05 U.S. Patent No. 11,918,685 Issues
2024-08-06 U.S. Patent No. 12,053,461 Issues
2025-06-24 U.S. Patent No. 12,336,984 Issues
2025-07-30 Defendant Notifies Plaintiff of ANDA No. 220151 Submission
2025-09-12 Complaint for Patent Infringement Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 12,053,461 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 12,053,461, “Amlodipine Formulations,” issued August 6, 2024.

The Invention Explained

  • Problem Addressed: The patent describes hypertension as a serious health issue affecting a large portion of the population (’461 Patent, col. 1:21-25). It implicitly addresses the difficulty certain patient populations (e.g., children, elderly) have with solid dosage forms like tablets and the inaccuracy and instability that can result from compounding liquid formulations by crushing tablets (’461 Patent, col. 9:48-64).
  • The Patented Solution: The invention is a stable, oral liquid formulation of amlodipine. The solution involves forming a less soluble salt of amlodipine, amlodipine benzoate, in situ by reacting a more soluble salt (such as amlodipine besylate) with sodium benzoate (’461 Patent, Abstract; col. 2:10-24). This reaction creates a stable suspension that does not require refrigeration, improving dosing accuracy and patient accessibility.
  • Technical Importance: This approach provides a ready-to-use, stable liquid formulation of a widely prescribed drug, which can improve patient compliance and dosing accuracy for those unable to swallow solid tablets (’461 Patent, col. 9:36-44).

Key Claims at a Glance

  • The complaint alleges infringement of one or more claims but does not specify which claims are asserted (Compl. ¶29). Independent claim 1 is representative of the patent's composition claims.
  • Claim 1 of the ’461 Patent: A method of treating hypertension, comprising administering an oral liquid formulation that includes:
    • amlodipine benzoate in an amount corresponding to 1.0 mg/ml amlodipine freebase;
    • about 3 mM of a citrate buffer;
    • about 0.2 mg/ml to about 10 mg/ml of sodium benzoate;
    • about 0.5 mg/ml of silicon dioxide;
    • about 7.5 mg/ml of hydroxypropyl methylcellulose;
    • about 0.15 mg/ml simethicone;
    • about 1.0 mg/ml of polysorbate 80; and
    • water.
  • The complaint reserves the right to assert additional claims (Compl. ¶29).

U.S. Patent No. 11,701,326 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 11,701,326, “Amlodipine Formulations,” issued July 18, 2023.

The Invention Explained

  • Problem Addressed: Similar to the ’461 Patent, this patent addresses the need for stable liquid amlodipine formulations (’326 Patent, col. 1:20-25). It further focuses on the manufacturing challenge of controlling the particle size of the amlodipine salt crystals, which is critical for the stability and consistency of a suspension.
  • The Patented Solution: The invention is a process for preparing amlodipine benzoate. The process involves subjecting an aqueous mixture containing a soluble amlodipine salt (e.g., besylate) and sodium benzoate to ultrasonic agitation (’326 Patent, Abstract; col. 2:8-15). This use of sonication is described as a method to form amlodipine benzoate particles with a desirable size distribution (e.g., D50 value between 5 µm and 40 µm) for a stable suspension.
  • Technical Importance: This process provides a method for manufacturing a stable amlodipine suspension with controlled physical characteristics, which is crucial for ensuring product uniformity, shelf-life, and accurate dosing.

Key Claims at a Glance

  • The complaint alleges infringement of one or more claims but does not specify which claims are asserted (Compl. ¶25). Independent claim 1 is representative of the patent’s process claims.
  • Claim 1 of the ’326 Patent: A process for preparing an amlodipine benzoate suspension, comprising the steps of:
    • providing an aqueous mixture comprising amlodipine besylate;
    • adding sodium benzoate to the aqueous mixture to form a first mixture; and
    • subjecting the first mixture to ultrasonic agitation at a frequency between 20 kHz and 100 kHz, thereby forming a second mixture comprising amlodipine benzoate.
  • The complaint reserves the right to assert additional claims (Compl. ¶25).

Multi-Patent Capsule: U.S. Patent No. 10,799,453 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 10,799,453, “Amlodipine Formulations,” issued October 13, 2020 (Compl. ¶18).
  • Technology Synopsis: This patent relates to stable oral liquid formulations of amlodipine. It claims methods of treatment using a formulation that comprises amlodipine benzoate formed in situ from a more soluble salt, along with specific excipients to create a stable suspension.
  • Asserted Claims: One or more unspecified claims (Compl. ¶19).
  • Accused Features: The Defendant’s ANDA Product, a generic amlodipine benzoate oral suspension, is alleged to infringe (Compl. ¶¶ 46-47).

Multi-Patent Capsule: U.S. Patent No. 11,471,409 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 11,471,409, “Amlodipine Formulations,” issued October 18, 2022 (Compl. ¶20).
  • Technology Synopsis: This patent is directed to processes for preparing amlodipine benzoate suspensions using ultrasonic agitation. The claims cover methods that specify parameters such as sonication frequency and duration to control the formation of amlodipine benzoate particles for a stable suspension.
  • Asserted Claims: One or more unspecified claims (Compl. ¶21).
  • Accused Features: The Defendant’s ANDA Product is alleged to infringe (Compl. ¶¶ 54-55).

Multi-Patent Capsule: U.S. Patent No. 11,484,498 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 11,484,498, “Amlodipine Formulations,” issued November 1, 2022 (Compl. ¶22).
  • Technology Synopsis: This patent claims stable oral liquid suspensions of amlodipine benzoate particles having a specific median particle diameter (D50 value). The invention is made by a process that includes mixing a soluble amlodipine salt with sodium benzoate.
  • Asserted Claims: One or more unspecified claims (Compl. ¶23).
  • Accused Features: The Defendant’s ANDA Product is alleged to infringe (Compl. ¶¶ 62-63).

Multi-Patent Capsule: U.S. Patent No. 11,918,685 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 11,918,685, “Amlodipine Formulations,” issued March 5, 2024 (Compl. ¶26).
  • Technology Synopsis: This patent claims methods of treating hypertension and coronary artery disease by administering a suspension of amlodipine benzoate particles with a defined median particle diameter (D50). The claims recite that the suspension is made by mixing a soluble amlodipine salt with sodium benzoate.
  • Asserted Claims: One or more unspecified claims (Compl. ¶27).
  • Accused Features: The Defendant’s ANDA Product is alleged to infringe (Compl. ¶¶ 78-79).

Multi-Patent Capsule: U.S. Patent No. 12,336,984 - "Amlodipine Formulations"

  • Patent Identification: U.S. Patent No. 12,336,984, “Amlodipine Formulations,” issued June 24, 2025 (Compl. ¶30).
  • Technology Synopsis: This patent claims methods for treating hypertension and coronary artery disease by administering a stable oral liquid formulation of amlodipine benzoate. The claims specify the components of the formulation, including the active ingredient and a list of required excipients.
  • Asserted Claims: One or more unspecified claims (Compl. ¶31).
  • Accused Features: The Defendant’s ANDA Product is alleged to infringe (Compl. ¶¶ 94-95).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendant Annora’s proposed generic amlodipine benzoate oral suspension, which is the subject of ANDA No. 220151 submitted to the FDA (Compl. ¶2).

Functionality and Market Context

  • The complaint alleges that by filing the ANDA, the Defendant has represented to the FDA that its product has the same active ingredients as and is bioequivalent to Azurity’s KATERZIA® product (Compl. ¶¶ 3, 35). The complaint does not provide further technical details about the formulation or manufacturing process of the accused ANDA Product, noting that the Defendant has not yet provided Azurity with access to the ANDA (Compl. ¶42).
  • The product is intended for commercial manufacture, use, and sale in the United States upon FDA approval as a generic alternative to KATERZIA® (Compl. ¶¶ 2, 9).

IV. Analysis of Infringement Allegations

The complaint does not provide a detailed infringement theory, specific asserted claims, or a claim chart. The infringement allegations are based on the statutory act of filing an ANDA under 35 U.S.C. § 271(e)(2)(A) to obtain approval for a generic drug claimed in the patents-in-suit (e.g., Compl. ¶46). The complaint alleges on "information and belief" that the future commercial manufacture, use, or sale of the ANDA Product would infringe the patents-in-suit (e.g., Compl. ¶47). No probative visual evidence provided in complaint.

  • Identified Points of Contention:
    • Factual Questions: Given the absence of technical disclosures in the complaint, the central factual dispute will be a comparison of the confidential details within Annora’s ANDA to the asserted patent claims. For the composition patents (e.g., ’461 Patent), this raises the question of whether the ANDA Product contains all claimed ingredients in the specified amounts. For the process patents (e.g., ’326 Patent), the question is whether the manufacturing method detailed in the ANDA employs the claimed steps, such as ultrasonic agitation.
    • Scope Questions: It may become a point of contention whether the processes Annora intends to use for manufacturing fall within the scope of the asserted process claims. Proving infringement of a process patent based on an ANDA filing can present unique challenges, as the analysis depends on the description of the manufacturing process provided to the FDA.

V. Key Claim Terms for Construction

  • The Term: "amlodipine benzoate" (from ’461 Patent, claim 1)

    • Context and Importance: The patents-in-suit repeatedly describe the invention as involving the in situ formation of amlodipine benzoate from a more soluble salt (’461 Patent, col. 2:10-18). Practitioners may focus on whether this term, as used in the claims, is limited to amlodipine benzoate formed in situ or if it could also read on a formulation where amlodipine benzoate is added as a pre-formed ingredient.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The body of claim 1 of the ’461 Patent simply recites "amlodipine benzoate" without specifying its method of formation, which may support an interpretation that covers the compound regardless of how it was incorporated.
      • Evidence for a Narrower Interpretation: The specification emphasizes that the in situ reaction is a key feature of the patented solution, stating "the amlodipine benzoate is formed by the reaction of a pharmaceutically acceptable salt of amlodipine that is more soluble in aqueous media" (’461 Patent, col. 2:20-23). This repeated emphasis could be used to argue for a narrower construction limited to the described formation method.

  • The Term: "ultrasonic agitation" (from ’326 Patent, claim 1)

    • Context and Importance: This term is central to the asserted process claims. The dispute may turn on what types and parameters of sonication are covered by this term. Practitioners may focus on whether any use of ultrasound meets this limitation or if it is implicitly limited by the specific frequencies, durations, and purposes described in the specification.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: Claim 1 of the ’326 Patent recites "subjecting the first mixture to ultrasonic agitation at a frequency between about 20 kHz and about 100 kHz," providing a broad frequency range without further limitations on duration or intensity.
      • Evidence for a Narrower Interpretation: The specification provides specific examples and preferred ranges, such as a frequency of "about 40 kHz" and a duration of "about 5 minutes and 30 minutes" (’326 Patent, col. 2:54-62). A defendant may argue that these specific embodiments should inform and limit the scope of the broader term in the claims.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon approval, Annora will induce infringement by instructing users via its proposed labeling to use the ANDA Product in an infringing manner and that the product has no substantial non-infringing uses (e.g., Compl. ¶¶ 47, 50).
  • Willful Infringement: The complaint alleges that the Defendant had "actual and constructive knowledge" of the patents-in-suit prior to submitting its ANDA and acted with "specific intent to infringe" (e.g., Compl. ¶¶ 48-49). While the term "willful" is not used in the infringement counts, the prayer for relief requests a finding that this is an "exceptional case under 35 U.S.C. § 285," which is the statutory basis for awarding attorneys' fees, often in cases of willful infringement or litigation misconduct (Compl. p. 19, ¶L).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A primary issue will be evidentiary and factual: as this Hatch-Waxman case proceeds into discovery, the central dispute will be how the specific formulation, ingredients, and manufacturing processes detailed in Annora’s confidential ANDA filing compare to the elements of Azurity's asserted composition and process claims.
  • A key legal question will concern infringement of process claims: can Azurity demonstrate that the manufacturing process described in the ANDA will practice the steps of the asserted process patents (e.g., ’326 Patent), particularly the use of "ultrasonic agitation," and how broadly will the court construe the scope of those method limitations?