Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 6,114,313
Introduction
U.S. Patent 6,114,313, granted on September 5, 2000, to Johnson & Johnson, relates to an innovative drug delivery system designed for the controlled release of active pharmaceutical ingredients (APIs). This patent has played a significant role in the pharmaceutical sector, particularly in improving drug efficacy and patient compliance through sustained-release formulations. This analysis examines the scope and claims of the patent, its technological landscape, and its influence on subsequent innovations.
Scope of U.S. Patent 6,114,313
The patent's scope encompasses a specific drug delivery system employing a drug-containing matrix within a biodegradable or bioerodible polymeric matrix. The core concept involves embedding an API in a polymer matrix to control its release over time, thereby reducing dosing frequency and improving pharmacokinetics. The scope also explicitly includes formulations involving various non-polymeric excipients to modulate release profiles, as well as methods for manufacturing such delivery systems.
Key Technical Focus
- Delivery Matrix Composition: The patent describes the use of biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA), polyanhydrides, and other biocompatible polymers.
- Drug Incorporation: APIs can be dispersed uniformly or encapsulated within the matrix for sustained, predictable release.
- Manufacturing Methods: Techniques include melting, solvent casting, extrusion, or compaction to produce controlled-release dosage forms.
- Application Range: The patent explicitly states applicability for a broad range of drugs, including peptides, proteins, small molecules, and other bioactives.
Claims Analysis
The patent includes 34 claims, with the core claims focusing on the composition and method of producing the controlled-release drug delivery system. The claims can be broadly categorized as follows:
Independent Claims
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Claim 1 (Composition):
It claims a controlled-release pharmaceutical composition comprising an API uniformly dispersed within a biodegradable polymer matrix, where the matrix is selected from a specified group (e.g., poly(lactic-co-glycolic acid)). The claim emphasizes the sustained release profile characterized by a specific release rate, suitable for once-daily dosing.
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Claim 13 (Method):
It discloses a method of manufacturing the controlled-release formulation via solvent casting, involving dissolving the polymer and API in a suitable solvent, then evaporating the solvent to form a solid matrix.
Dependent Claims
Dependent claims specify particular polymers, APIs, or manufacturing parameters, such as:
- Use of specific polymers like PLGA with certain lactide/glycolide ratios [Claims 3, 4].
- APIs with particular molecular weights or solubility characteristics [Claims 6-8].
- Alternative manufacturing approaches, including extrusion and surface coating methods [Claims 15-20].
- Variations in matrix geometry and size for optimizing release profiles [Claims 21-24].
Scope of Claims
The scope broadly covers biodegradable polymer matrices containing diverse APIs, with particular emphasis on sustained, predictable release profiles that enable once-daily administration. The claims are sufficiently flexible to encompass various formulations while remaining specific to the methodology of controlled release.
Patent Landscape and Technological Context
Historical and Competitive Context
At the time of the patent application (filed in 1997), sustained-release drug delivery systems were advancing rapidly. Key innovations focused on improving bioavailability, reducing dosing frequency, and enhancing patient compliance. PLGA-based systems, in particular, gained prominence due to their FDA-approved status and biodegradability.
Related Patents and Innovations
- Prior Art: Patents such as U.S. Patent 5,700,546 (assigned to Alza Corporation), which covers biodegradable implant formulations, and U.S. Patent 5,731,163 (Hill et al.), focused on controlled release matrices.
- Post-Grant Innovations: Subsequent patents have expanded upon the concepts established by 6,114,313, including more complex delivery systems, multilayered implants, and targeted release mechanisms. For instance, US Patents 7,459,542 and 8,532,283 explore multi-layered polymers for precise release kinetics.
Selective Patent Expiry and Freedom to Operate
Since the patent was granted in 2000 and filed around 1997, it is likely expired or nearing expiration, given the standard 20-year patent term, assuming maintenance fees were paid. Its expiration has facilitated broader development and commercialization of biodegradable, controlled-release formulations.
Implications for the Pharmaceutical Industry
The patent cemented a foundational approach for biodegradable polymer-based controlled release systems. Its broad claims encouraged a wave of generics and branded therapeutics employing similar technology. Companies such as Purdue Pharma, Alkermes, and others have built upon these principles, developing formulations for opioids, anticancer agents, and vaccines.
The patent’s scope inspired innovations in:
- Targeted drug delivery: Adjusting polymer properties to target specific tissues or release sites.
- Combination formulations: Incorporating multiple drugs within a single matrix.
- Biodegradable implants: Developing implantable systems with sustained release over months or years.
Regulatory and Commercial Landscape
The controlled-release system configured by this patent aligns with FDA guidelines for sustained-release implants and matrices. Several products leveraging similar technology have received regulatory approval, indicating the pathway to successful commercialization based on such foundational patents.
Key Takeaways
- Broad yet specific: The patent's claims encompass a wide range of biodegradable polymer matrices and drugs, providing a flexible platform for sustained-release formulations.
- Technological influence: It catalyzed advancements in biodegradable drug delivery systems, influencing subsequent innovations and filings.
- Expiration benefits: Its likely expiration creates opportunities for new formulations, generics, and improved drug delivery devices.
- Regulatory alignment: The scope supports regulatory pathways for once-daily or long-acting drug products.
- Strategic positioning: Overlapping with other patents, the strategic navigation of the patent landscape requires careful analysis, especially when developing novel controlled-release therapies.
Conclusion
U.S. Patent 6,114,313 represents a pivotal advancement in biodegradable, controlled-release drug delivery systems. Its comprehensive claims and broad scope fostered innovation across pharmaceuticals, enabling safer, more effective, and patient-friendly formulations. The patent landscape rooted in this innovation continues to evolve, with subsequent patents extending its principles into advanced, targeted technologies.
FAQs
1. Is U.S. Patent 6,114,313 still enforceable?
No. The patent, filed in 1997 and granted in 2000, has likely expired or is nearing expiration, providing freedom to operate for new formulations employing similar controlled-release biodegradable systems.
2. How does this patent influence current drug delivery formulations?
It set the foundational principles for biodegradable polymer matrices, influencing numerous patented formulations and commercial products for sustained-release drug delivery.
3. Can similar controlled-release systems be developed without infringing this patent?
Yes, alternative polymers, manufacturing methods, or release mechanisms not covered by the claims would potentially circumvent infringement, especially post-expiration.
4. What types of drugs are suitable for delivery via the system described in this patent?
A broad spectrum, including peptides, small molecules, proteins, and bioactives with suitable compatibility with biodegradable polymers, particularly those requiring long-term release.
5. What are common challenges in developing biodegradable controlled-release systems based on this patent?
Maintaining consistent release kinetics, ensuring polymer biocompatibility, controlling API stability during manufacturing, and complying with regulatory standards.
References
[1] U.S. Patent 6,114,313. Johnson & Johnson, "Controlled-release pharmaceutical composition." 2000.
