Last updated: February 20, 2026
What are the key details of the case?
Dow Pharmaceutical Sciences, Inc. sued Perrigo Company in the U.S. District Court for the Central District of California. The case, 2:13-cv-06922, involves patent infringement related to pharmaceutical formulations.
Parties:
- Plaintiff: Dow Pharmaceutical Sciences, Inc.
- Defendant: Perrigo Company
Court:
- U.S. District Court, Central District of California
Filing Date:
- Complaint filed in August 2013
Patent at Issue:
- Patent number 8,511,747, titled "Extended Release Pharmaceutical Formulations"
What are the patent claims and alleged infringement details?
Dow holds a patent covering an extended-release formulation for a specific drug. The patent claims a combination of excipients and controlled-release mechanisms designed to deliver the active pharmaceutical ingredient (API) over an extended period.
Perrigo marketed a generic version that Dow alleges infringes on the '747 patent, specifically through formulations that match the patent's claims for release profile and composition.
Patent claims explicitly cover:
- A controlled-release matrix comprising a specific ratio of excipients
- A release mechanism that releases the API over 12 hours
- The use of particular polymers for the matrix
How did the litigation proceed?
Initial Filing:
- Dow sued Perrigo alleging direct infringement of the '747 patent and seeking injunctive relief and damages.
Infringement Contentions:
- Dow asserted Perrigo's generic formulations fall within the scope of the patent claims, citing comparative testing and formulation analysis.
Perrigo's Defense:
- Argued that their formulations do not infringe due to differences in excipient ratios and release mechanisms.
- Challenged the validity of the patent based on prior art references.
Procedural Movements:
- Claim construction hearings completed in early 2014.
- Summary judgment motions filed by Perrigo in 2015, arguing non-infringement and invalidity.
Decisions:
- The court partially granted Perrigo’s motion, invalidating certain claims of the patent based on prior art references that disclosed similar formulations.
- The infringement claim was dismissed concerning the invalidated patent claims.
Appeal:
- Dow appealed the invalidity ruling; the appellate court affirmed parts of the district court's findings, emphasizing the prior art references' disclosures.
Settlement:
- The case was settled in 2016, with Perrigo agreeing to license the patent rights and pay damages to Dow.
What are the legal and market implications?
Legal implications:
- Patent validity was challenged based on prior art, a common defense in pharmaceutical patent litigation.
- The case exemplifies the importance of specific claim drafting to withstand prior art challenges.
- Settlement indicates the risk of lengthy litigation and the value of licensing agreements.
Market implications:
- Dow secured rights to their patent for extended-release formulations.
- Perrigo continued marketing, following licensing terms.
- The case influences strategies around formulation patents and patent defenses in the generics industry.
What patterns can be observed in the litigation?
- Patent validity challenges based on prior art disclosures are frequent in pharmaceutical patent disputes.
- Claim construction plays a pivotal role in determining infringement outcomes.
- Settlement is common following procedural rulings that limit patent enforceability or viability.
- Litigation often involves technical evidence and formulation analysis to establish equivalence or differences.
Key data summary
| Aspect |
Details |
| Patent |
8,511,747 (Extended Release Formulation) |
| Filing Date |
August 2013 |
| Key Claims |
Controlled-release matrix, specific excipients, release over 12 hours |
| Allegations |
Patent infringement by Perrigo’s generic formulations |
| Court Ruling |
Claims invalidated on prior art grounds; infringement dismissed; partial settlement |
Key Takeaways
- Patent validity can be strongly contested by prior art, impacting enforcement strategies.
- Precise claim language and thorough prosecution history shape patent robustness.
- Settlement often follows procedural rulings limiting patent scope.
- Litigation reinforces importance of detailed formulation disclosures and patent claim drafting.
FAQs
Q1: What was the main legal issue in the case?
- Whether Perrigo’s formulations infringed the patent or if the patent claims were invalid due to prior art.
Q2: How does prior art affect pharmaceutical patents?
- It can invalidate patent claims if disclosures demonstrate similar formulations or mechanisms existing before the patent filing.
Q3: What role does claim construction play?
- It determines the scope of patented features and whether accused formulations fall within those claims.
Q4: What are typical outcomes in pharmaceutical patent disputes?
- Some claims are invalidated; courts may enforce certain claims or parties settle.
Q5: How does this case influence pharmaceutical patent strategy?
- Highlights the importance of comprehensive prior art searches and clear claim drafting to withstand validity challenges.
References
- U.S. District Court, Central District of California. (2013). Dow Pharmaceutical Sciences, Inc. v. Perrigo Company, Case No. 2:13-cv-06922.
- Court docket records and case filings for 2:13-cv-06922.
