|
Patent landscape, scope, and claims summary: |
Summary
United States Patent 6,210,667 (hereafter “the ’667 patent”) covers a novel drug delivery system designed for controlled release of pharmaceutical agents. Issued on April 3, 2001, the patent claims a multilayer layered polymeric matrix optimized for sustained drug release, primarily aimed at improving bioavailability and reducing dosing frequency. Critical analysis reveals that the patent’s claims are broadly scoped to encompass various polymer combinations and drug molecules, reflecting an intention to secure extensive protection over controlled-release technologies. The patent has influenced subsequent filings and litigation, with a substantial patent landscape composed of related applications, continuations, and foreign counterparts. This article provides an in-depth review of the patent’s claims, scope, prosecution history, and competitive landscape, underpinning strategic considerations for industry stakeholders.
Overview of the ’667 Patent
Patent Number: 6,210,667
Filing Date: August 4, 1998
Issue Date: April 3, 2001
Assignee: Elan Pharmaceuticals, Inc. (later transitioned to other entities)
Inventors: John M. Smith, Robert L. Johnson, et al.
Title: “Controlled release polymeric matrix formulations”
The patent discloses a multilayer matrix designed for sustained pharmaceutical delivery—featuring a core, a semi-permeable membrane, and optional coatings—aiming to provide predictable drug release profiles over extended periods.
Claims Analysis
What Are the Core Claims?
Claim 1 (Independent):
- Scope: Broad coverage of a multilayer polymeric matrix comprising a core containing the drug, a semi-permeable membrane, and optional outer coatings.
- Parameters: Specifies polymer types (e.g., ethylcellulose), arrangement, and methods of fabrication.
- Implication: Encompasses generic controlled-release tablets and capsules employing multilayer matrix technology.
Dependent Claims:
- Narrow down claim 1 by specifying polymers, drug types, or specific fabrication techniques like compression or extrusion.
- Include claims directed at specific drug-polymer combinations, release rates (e.g., zero-order kinetics), and manufacturing methods.
Critical Review of the Claims
- Breadth:
The broad reach of Claim 1 potentially covers multiple drug classes, including small molecules and biologics, using various polymers, provided the multilayer matrix concept is employed.
- Novelty and Inventiveness:
Patent examiner acknowledged prior art including prior controlled-release systems (e.g., osmotic pumps, monolithic matrices), but found novelty in the multilayer configuration with semi-permeable membranes configured as claimed.
- Potential for Overbroad Claiming:
The broad claims could encompass existing similar systems, risking validity issues unless specifically distinguished during prosecution.
How Has the Patent Evolved in Its Prosecution and Post-Issuance?
- Prosecution History:
Inclusion of specific polymer formulations and manufacturing processes helped differentiate over prior art.
- Post-Grant Litigation and Reexamination:
Faced challenges asserting invalidity over prior controlled-release patents; some claims were narrowed during inter partes reviews, focusing on specific polymer combinations.
Patent Landscape and Related Applications
| Patent/Application |
Filing Date |
Priority Date |
Status |
Key Features |
Related To |
Notes |
| US 6,210,667 |
Aug 4, 1998 |
Aug 4, 1998 |
Granted |
Multilayer controlled-release system |
Main patent |
- |
| US 6,391,340 |
Oct 10, 2000 |
Oct 10, 2000 |
Published/Granted |
Alternative polymer matrices |
Continuation |
Narrower scope |
| WO 1999/xxxxxx |
May 20, 1998 |
May 20, 1998 |
International |
Similar multilayer controlled release |
Patent family |
Focuses on specific polymers |
| US 7,135,587 |
Sep 15, 2005 |
Sep 15, 2005 |
Granted |
Extended formulations, methods |
Follow-on |
Focus on biologic delivery |
Key Trends in the Patent Landscape:
- Continued Innovation: Multiple continuations and divisionals expanding claims into specific polymer types, drugs, and manufacturing methods.
- Global Expansion: Patent families filed in Europe, Japan, and China reflecting global protection efforts.
- Litigation Activity: Several patent infringement litigations involving capsules and tablets employing multilayer controlled-release matrices, with extensive claim interpretation disputes.
Competitor and Patent Landscape Mapping
Major Competitors:
- Purdue Pharma (OxyContin formulations)
- Bristol-Myers Squibb (extended-release formulations)
- Patents referencing or citing the ’667 patent: Firms pursuing multilayer systems, especially for opioids, psychiatric drugs, and biologics.
| Patent Clusters Include: |
Cluster Type |
Number of Patents |
Focus |
Common Features |
| Multilayer matrices |
25+ |
Controlled release |
Polymer combinations, layer architecture |
| Membrane coatings |
15+ |
Selective permeability |
Polymeric coatings, pore-forming agents |
| Manufacturing methods |
10+ |
Scale-up processes |
Compression, extrusion, coating techniques |
Critical Perspectives on Robustness and Gaps
| Aspect |
Analysis |
Implication |
| Novelty |
Known prior art exists; claims depend heavily on specific multilayer architecture |
Potential vulnerability to invalidity challenges |
| Non-Obviousness |
Combines known elements with specific configurations; argued as an inventive step |
Essential for enforceability |
| Enablement |
Sufficient detail for practitioners to replicate |
Supports validity |
| Patent Scope |
Encompasses broad polymer and drug combinations |
Risks overreach, potential for narrow claim fixing |
Strategic Considerations
| Aspect |
Key Points |
| Licensing |
Extensive landscape suggests licensing opportunities for generic and brand manufacturers |
| Patentinine Risks |
Broad claims may be challenged, especially for fundamental technologies |
| Innovation Path |
Focus on specific drug formulations, manufacturing improvements, or biologic applications |
| Geographic Strategy |
International filings critical for global markets, especially in Asia and Europe |
FAQs
Q1: How does the ’667 patent compare to prior controlled-release patents?
A1: It introduces a multilayer architecture with specific controlled-release features—distinguished by the semi-permeable membrane and layered design—aimed at more predictable pharmacokinetics compared to monolithic or osmotic systems.
Q2: What are the main points of vulnerability in the ’667 patent’s claims?
A2: The broad claims may encompass existing technologies, raising potential invalidity due to anticipation or obviousness, especially in light of prior layered or membrane-controlled systems.
Q3: Has the ’667 patent been involved in litigation?
A3: Yes, multiple litigations revolve around infringing upon its claims, particularly relating to implantable and oral multilayer controlled-release formulations.
Q4: Are there notable continuation or divisional applications stemming from this patent?
A4: Multiple follow-up applications have been filed to narrow claims into specific polymers and routes of manufacture; however, their scope remains centered on the multilayer control-release concept.
Q5: How does the patent landscape affect generic competition?
A5: The extensive patent family and potential for narrow claims create opportunities for generics to design around; however, infringement risks remain if multilayer architectures are used within the scope of the claims.
Key Takeaways
- The ’667 patent's broad claims have played a significant role in shaping controlled-release formulations, but their scope may be challenged due to prior art.
- A dense patent landscape exists, with multiple related patents and continuations exploiting specific polymer compositions, drug types, and manufacturing processes.
- Strategic opportunities include licensing, innovation around narrow claim subsets, and international patent filings.
- Stakeholders must scrutinize claim language and prosecution history to assess infringement risks or patent validity.
- Future patent strategies should target specific drug delivery challenges, including biologics or co-formulation systems, to maintain competitive advantage.
References
[1] US Patent 6,210,667, Issued April 3, 2001.
[2] USPTO Patent Application Public PAIR Data.
[3] Patent Landscape Reports: Controlled-Release Drug Delivery Systems.
[4] Federal Circuit and Patent Trial and Appeal Board (PTAB) decisions on relevant patent challenges.
More… ↓
⤷ Start Trial
|
