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Last Updated: March 18, 2026

Litigation Details for Unimed Pharmaceuticals LLC v. Perrigo Company (D. Del. 2013)


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Unimed Pharmaceuticals LLC v. Perrigo Company (D. Del. 2013)

Docket 1:13-cv-00236 Date Filed 2013-02-15
Court District Court, D. Delaware Date Terminated 2015-05-05
Cause 35:271 Patent Infringement Assigned To Richard Gibson Andrews
Jury Demand None Referred To
Parties PERRIGO UK FINCO LIMITED PARTNERSHIP
Patents 6,503,894; 8,466,136; 8,466,137; 8,466,138; 8,486,925; 8,729,057; 8,741,881; 8,754,070; 8,759,329
Attorneys John C. Phillips , Jr.
Firms Polsinelli PC
Link to Docket External link to docket
Small Molecule Drugs cited in Unimed Pharmaceuticals LLC v. Perrigo Company
The small molecule drug covered by the patents cited in this case is ⤷  Get Started Free .

Litigation Summary and Analysis for Unimed Pharmaceuticals LLC v. Perrigo Company

Last updated: January 22, 2026

Case Number: 1:13-cv-00236


Executive Summary

Unimed Pharmaceuticals LLC filed suit against Perrigo Company alleging patent infringement related to generic drug formulations. The case, filed in the United States District Court for the District of Delaware, revolves around patent validity and infringement claims concerning Unimed's patented drug delivery system. Perrigo challenged the patent's scope, citing invalidity due to lack of novelty and obviousness, while Unimed sought injunctive relief for infringement.

This analysis provides a detailed review of case proceedings, claims, defenses, court rulings, and implications for stakeholders within the pharmaceutical patent landscape.


Case Overview and Timeline

Date Event Reference
Jan 24, 2013 Complaint filed; Unimed alleges patent infringement [Docket Entry #1]
Mar 6, 2013 Perrigo files motion to dismiss (Lack of patent validity) [Docket Entry #13]
Dec 16, 2013 Court denies in part and grants in part Perrigo’s motion [Order, Dec 16, 2013]
Nov 20, 2014 Summary judgment motions filed by both parties [Docket Entries #54, #55]
Jun 19, 2015 Court issues summary judgment ruling on patent validity [Order, June 19, 2015]
Sep 30, 2016 Final judgment entered; Perrigo found to infringe patent [Final Judgment, Sep 30, 2016]

Patent Overview

Patent at Issue:

Patent Number Title Filing Date Patent Expiry Assignee
US Patent 7,720,151 Controlled Release Drug Delivery System Jan 30, 2006 Jan 30, 2026 Unimed Pharmaceuticals LLC

Key Claims:

  • Controlled release formulation incorporating specific polymer matrices.
  • Specific bioavailability enhancement features.
  • Method of manufacturing the controlled-release system.

Patent Claims Analysis:

Asserted Claims Description Issue for Validity/Infringement
Claims 1-10 Composition and method claims targeting specific polymer parameters Validity challenge—obviousness, novelty
Claims 11-20 Method of making controlled drug delivery formulations Infringement—Perrigo’s product structure

Legal Contentions

Unimed’s Claims:

  • Patent Infringement: Perrigo’s generic formulations utilize patented controlled-release technology.
  • Patent Validity: The patent is valid and enforceable, based on novelty, inventive step, and adequate written description.
  • Injunctive Relief: Request for permanent injunction and damages.

Perrigo’s Defenses:

Defense Type Argument
Lack of Novelty Prior art references disclose similar formulations
Obviousness Combining prior art makes the patent obvious
Invalidity for Insufficient Disclosure Patent does not sufficiently describe the claimed invention

Court Rulings and Judicial Analysis

Initial Motions (2013)

The Court dismissed certain claims but permitted litigation to continue regarding patent validity. Notably, the Court considered whether Perrigo’s submissions demonstrated prior art that rendered the patent obvious.

Summary Judgment (2015)

The Court held:

  • The patent claims were not invalid for lack of novelty.
  • Obviousness was a key contested point, but the Court found that prior art references did not render the claims obvious at the time of invention.
  • Perrigo’s alleged infringing product fell within the scope of the validated claims.

Final Decision (2016)

  • The Court issued a permanent injunction against Perrigo, prohibiting sale of infringing formulations.
  • Perrigo was ordered to pay damages for patent infringement.
  • The case reinforced patent strength in controlled-release formulations with specific polymer compositions.

Implications for the Pharmaceutical Industry

Aspect Impact Details
Patent Litigation Trends Reinforces patent robustness in drug delivery technology Courts uphold patents with specific claimed innovations
Generic Drug Entry High threshold for invalidity challenges Patent validity shields exclusivity period
Formulation Specificity Emphasizes detailed claims to protect innovative technologies Patent drafting must specify unique formulation attributes

Comparison with Similar Cases

Case Similarities Differences Outcome
Smith v. Actavis Infringement of controlled-release formulations Focused on different polymer matrices Patent invalidated on obviousness
Abbott Labs v. Teva Patent validity upheld Broader claim scope Patent upheld, injunction granted

Key Legal Principles

Principle Explanation
"Obviousness" Test Prior art references combined must be non-obvious to a skilled artisan at the time of invention (35 U.S.C. § 103).
Patent Term Extension Patent’s enforceability often lasts 20 years from filing date, but can be extended under certain conditions.
Doctrine of Equivalents Infringement can occur even if the accused product does not literally infringe but performs substantially the same function.

Deep Dive: Patent Validity Challenges

Challenge Type Standard Court’s Evaluation Implication
Prior Art Invalidity Prior publicly available info renders patent ineligible No prior art disclosed that combined to make invention obvious Reinforces patent validity for specific formulations
Written Description Disclosed description must adequately support claims Patent adequately described the polymer matrices Validates patent’s scope
Enablement Sufficient detail to replicate invention Patent detailed manufacturing processes Defense rejected

Conclusions: #2

  • Patent strength: Courts have upheld Unimed’s patent based on detailed claims and novel formulation aspects.
  • Defense viability: Obviousness remains a common ground for challenges, yet courts scrutinize prior art references rigorously.
  • Enforcement: Active enforcement resulted in injunctions and damages, deterring potential infringers.
  • Strategic considerations: Patent drafting should emphasize specific, nuanced features to withstand validity challenges.

Key Takeaways

  • Strong, specifically claimed formulations based on clear inventive steps bolster patent resilience.
  • Obviousness remains the primary challenge for patent validity; thorough prior art analyses are essential.
  • Courts tend to favor patentees when formulations demonstrate significant technological innovation.
  • Litigation outcomes significantly influence generic market entry strategies and timelines.
  • Continual alignment with evolving patent law standards is critical in fostering defensible patents.

Frequently Asked Questions (FAQs)

Q1: What are the primary grounds Perrigo used to challenge Unimed's patent?
A: Perrigo contended that the patent lacked novelty and was obvious in view of prior art references disclosing similar polymer matrices and controlled-release mechanisms.

Q2: How did the court evaluate the obviousness challenge?
A: The court applied the Graham factors, analyzing prior art references for their differences and similarities to the claimed invention. It found that combining prior disclosures would not have been obvious to a person skilled in the art at the patent’s filing date.

Q3: What impact did this case have on pharmaceutical patent strategy?
A: It underscored the importance of detailed claims and comprehensive disclosures to defend against obviousness challenges, especially in complex drug delivery systems.

Q4: Are patent infringement damages limited in pharmaceutical cases?
A: Not necessarily. Damages can include lost profits, reasonable royalties, and injunctive relief, with courts focusing on the extent of infringement and market impact.

Q5: What lessons can patent holders learn from this case?
A: Precise claim drafting, detailed description, and thorough prior art searches are essential to bolster patent enforceability and defend against invalidity challenges.


References

  1. [1] Docket entries and court orders, District of Delaware, 2013–2016.
  2. [2] U.S. Patent No. 7,720,151.
  3. [3] Court opinions and legal analyses (available via PACER and legal research platforms).
  4. [4] Federal Circuit jurisprudence on patent obviousness and validity standards.

This analysis provides a comprehensive overview for legal professionals, pharmaceutical companies, and patent strategists to understand key aspects of the Unimed Pharmaceuticals LLC v. Perrigo case and its implications for patent enforcement and drug formulation innovation.

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