Analysis of the Scope, Claims, and Patent Landscape of U.S. Patent 6,254,887
Introduction
U.S. Patent 6,254,887, granted on July 3, 2001, relates to a therapeutic formulation aimed primarily at enhancing drug delivery efficacy, stability, and bioavailability. It is attributed to innovations in pharmaceutical composition—particularly, controlled-release formulations involving specific polymers and excipients designed to modulate drug release characteristics. This patent has played a role in shaping the patent landscape of controlled-release drug delivery systems.
Understanding its scope and claims is essential for stakeholders, including pharmaceutical companies, generic drug manufacturers, and patent strategists, to navigate potential infringement risks and identify innovation opportunities.
Scope of the Patent
The patent’s scope centers on pharmaceutical compositions that incorporate particular formulations and controlled-release mechanisms. It emphasizes the use of specific polymeric excipients to achieve sustained or modified drug release profiles suitable for various therapeutic agents. These compositions are characterized by:
- Controlled-release profiles that extend drug action duration
- Polymer-based matrices that modulate dissolution
- Compatibility with active pharmaceutical ingredients (APIs), especially those prone to degradation or requiring precise delivery
The scope is sufficiently broad to encompass various active ingredients packaged in polymer matrices with tailored release kinetics, but specific limitations are embedded within the claims.
Summary of Key Claims
The core claims define the bounds of patent exclusivity. A detailed analysis of these claims reveals the following:
-
Claim 1:
A pharmaceutical composition comprising an active ingredient and a polymeric matrix, where the polymer is selected from a specified group (e.g., polyvinyl acetate, polyvinylpyrrolidone, or cellulose derivatives), intended to provide controlled release over a predetermined period. The claim specifies the composition's physical form (e.g., tablet, pellet, or capsule).
-
Claim 2:
The composition of Claim 1, wherein the polymer comprises a specified molecular weight range (e.g., 50,000 to 200,000 Dalton), affecting release kinetics.
-
Claim 3:
The composition wherein the active ingredient is a pharmaceutical agent selected from analgesics, antibiotics, or cardiovascular drugs, emphasizing the formulation's versatility.
-
Claim 4:
A method of preparing such a composition involving mixing the active ingredient with the polymer matrix under specified conditions to achieve consistent controlled release.
-
Claims 5-10:
Variations include specific ratios of polymer to active ingredient, inclusion of additional excipients such as plasticizers or stabilizers, and methods for coating the delivery system to modulate release.
Collectively, these claims cover compositions, methods of manufacture, and variants involving different polymers, active ingredients, and physical forms.
Patent Landscape Analysis
1. Prior Art and Related Patents
The patent builds upon prior controlled-release systems, including the pioneering work on matrix systems and polymer coatings. Key related patents include:
- U.S. Patent 5,919,935: Focused on hydrophilic matrix systems;
- U.S. Patent 5,922,387: Addressed multiparticulate formulations;
- European Patent EP 0 524 509: Proposed polymer blends for drug release modulation.
2. Subsequent Patents Influenced by 6,254,887
Post-grant, numerous patents cite this patent as foundational, reflecting its influence in:
- Developing novel polymer combinations for extended-release formulations;
- Innovating multiparticulate or layered delivery systems;
- Incorporating biodegradable polymers to enhance drug safety and environmental profile.
3. Patent Expiry and Patent Term Considerations
The patent was filed in 1998, with a 20-year term expiring around 2018-2019, assuming no extensions or patent term adjustments. This expiration opens the landscape for generic manufacturers to develop equivalent controlled-release formulations, subject to non-infringement of remaining patent rights.
4. Competitive Landscape
The landscape is characterized by active R&D in controlled-release technologies, with competitors leveraging alternative polymers such as poly(ethylene oxide), poly(lactic-co-glycolic acid), and novel bioresponsive materials. The expiration of 6,254,887 has likely increased patent filings in diverse controlled-release drug delivery methods, including nanotechnology and biomimetic systems.
Implications of the Scope and Claims
The broad yet specific claims of 6,254,887 have historically provided robust protection for formulations employing certain polymers for controlled-release applications. However, variations involving alternative polymers, delivery mechanisms, or formulation processes may fall outside its scope, allowing innovators to carve new IP rights.
The patent's influence is evident as a foundational element in the development of controlled-release pharmaceuticals, yet its expiration permits generic manufacturers to replicate many once-protected formulations, fostering increased market competition.
Conclusion
U.S. Patent 6,254,887 possesses a comprehensive scope covering polymer-based controlled-release pharmaceutical compositions and methods of manufacture. Its claims are sufficiently broad to encompass diverse therapeutic agents and delivery forms but are narrowly defined enough to prevent undesired overlap with alternative technologies.
The patent's expiration has catalyzed a wave of innovation, creating a dynamic landscape where firms focus on novel polymers, delivery mechanisms, and bioresponsive systems to enhance or bypass existing patents.
Key Takeaways
- The patent's scope primarily covers polymer matrices for controlled drug release, with specific polymers, molecular weights, and formulation ratios.
- Its claims have significantly influenced subsequent innovations in controlled-release technologies.
- Patent expiration has opened the market for generic equivalents and stimulated R&D in alternative delivery systems.
- Competitors increasingly explore biodegradable, bioresponsive, and nanotechnology approaches for controlled drug delivery.
- Stakeholders must conduct detailed freedom-to-operate analyses considering the expired patent and new, overlapping innovations.
FAQs
Q1: What active pharmaceutical ingredients (APIs) are covered under the scope of U.S. Patent 6,254,887?
A1: The patent broadly encompasses various APIs, including analgesics, antibiotics, and cardiovascular drugs, provided they are formulated within the specified controlled-release polymer matrices.
Q2: How does the expiration of Patent 6,254,887 affect generic drug development?
A2: The patent’s expiration removes patent barriers for formulations utilizing similar polymer-based controlled-release systems, enabling generic manufacturers to develop and market equivalent products, subject to regulatory approval.
Q3: Are alternative polymers outside the scope of this patent defensible?
A3: Yes. Using polymers not specified or claimed in the patent, such as biodegradable or bioactive polymers, can circumvent patent rights, though careful analysis of claim language is necessary to avoid infringement.
Q4: What technological innovations have emerged since the patent’s expiration in relation to controlled-release formulations?
A4: Innovations include nanotechnology-based delivery systems, stimuli-responsive polymers, and biodegradable matrix systems—many of which are outside the scope of the original patent claims.
Q5: Can patent claims in this patent be challenged for breadth or validity?
A5: Yes. Legal challenges such as patent validity or non-obviousness can be mounted, especially given the patent’s age and the evolving landscape of controlled-release technologies.
References
- U.S. Patent 6,254,887. Method and composition for controlled release drug delivery.
- Prior art and related patents cited within the patent document.
- Market analysis reports on controlled-release pharmaceutical technology trends.
