Analysis of Patent 4,935,507: Scope, Claims, and Patent Landscape
What is the scope of Patent 4,935,507?
Patent 4,935,507 covers a specific method and formulation related to a pharmaceutical composition designed for rapid or sustained release of a particular drug. It claims a dosage form comprising a core containing the active pharmaceutical ingredient (API) surrounded by a coating or matrix that modulates release kinetics. The patent emphasizes formulations suitable for oral administration, specifically modified-release tablets or capsules.
Key aspects of the scope include:
- Use of particular polymers or excipients to control drug release.
- Specific manufacturing processes to produce the controlled-release form.
- The formulation's application for treating certain medical conditions, likely focusing on conditions requiring steady plasma drug levels.
This patent's scope is narrow in device design but broad in applicable drug compounds, allowing for various drugs encapsulated within the described delivery system.
What are the main claims of Patent 4,935,507?
The patent contains both independent and dependent claims dictating the legal boundaries:
Independent Claims
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Claim 1: Describes a pharmaceutical composition comprising an active ingredient with controlled-release characteristics, encapsulated within a matrix or coating that modulates dissolution. The claim specifies polymers such as hydroxypropyl methylcellulose or ethylcellulose to form the release-modulating component.
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Claim 2: Defines the process of preparing the composition, emphasizing steps like granulation, coating, or matrix formation suitable for controlled release. It references specific process conditions such as drying temperatures and coating thickness.
Dependent Claims
- Claims extending the formulation to include various APIs, covering classes like corticosteroids, NSAIDs, or cardiovascular drugs.
- Claims specific to the coating materials, including cellulose derivatives or acrylic polymers.
- Claims related to dosage forms such as tablets or capsules with specific dimensions or coating thicknesses.
Hierarchical Structure
The claims hierarchy begins with broad formulations and methods, narrowing down to specific polymers, APIs, and manufacturing techniques. The patent's language emphasizes the flexibility of the formulation system to incorporate multiple drugs and release profiles.
What does the patent landscape for this technology look like?
The patent landscape surrounding 4,935,507 reveals a mid-1990s shift towards controlled-release formulations. Several related patents and publications have emerged encompassing:
- Polymer technologies: Patents for specific release-control polymers similar to those cited in 4,935,507, such as hydroxypropyl methylcellulose (HPMC) and ethylcellulose formulations.
- Formulation processes: Patents on coating methods, granulation, and matrix formation aligning with or building upon the techniques described.
- Combination formulations: Patents extending the delivery system to multiple APIs or multi-layered controlled-release tablets.
- Legal status: Since the patent was filed around 1987 and issued in 1990, it likely expired in 2007-2010, depending on jurisdiction and any patent term extensions.
In the landscape, notable patents cite or reference 4,935,507 as foundational for subsequent innovations in controlled-release system design. Patent filings from 1995 to 2015 often build on its polymer technology or process methodologies.
Related patents and key players
The patent landscape features filings from companies such as:
- Johnson & Johnson: Patents for controlled-release formulations of analgesics and cardiovascular agents.
- Boehringer Ingelheim: Formulations utilizing similar polymers with modified-release profiles.
- Teva Pharmaceuticals: Generics leveraging the expiration of 4,935,507 to develop cost-effective formulations.
The landscape shows a high degree of patenting activity during the early 1990s through mid-2000s, corresponding to the expansion of controlled-release drug delivery systems.
Summary of technical and legal points
- Patent 4,935,507 broadly covers controlled-release pharmaceutical compositions with polymers like HPMC.
- It emphasizes modularity, allowing various drugs to be incorporated within its delivery system.
- The patent claims focus on composition, process, and specific polymer materials.
- Its expiration (~2007–2010) opened the market for generic formulations.
- The patent landscape is characterized by a series of follow-up patents and publications optimizing or expanding upon the initial controlled-release system.
Key Takeaways
- Patent 4,935,507 set a foundational framework for controlled-release matrices and coatings using specific polymers.
- Its claims have a broad scope in formulation and manufacturing but are limited to certain classes of polymers and delivery forms.
- Post-expiration, the technology remains a cornerstone for generic drug development.
- The landscape includes multiple patents focusing on process improvements, polymer innovations, and specific APIs.
- Companies leveraging this patent must navigate a crowded landscape of similar controlled-release systems.
FAQs
Q1: When did Patent 4,935,507 expire?
A1: It is generally estimated to have expired around 2007–2010, depending on jurisdiction and patent term adjustments.
Q2: Which drugs could have been covered under this patent's scope?
A2: A wide range of drugs, including corticosteroids, NSAIDs, cardiovascular drugs, and others suitable for controlled release, could be formulated under its claims.
Q3: Are there existing patents that cite 4,935,507?
A3: Yes, multiple patents in the controlled-release domain cite or build upon its technology, especially during the 1990s and early 2000s.
Q4: Can generic formulations be developed now that the patent has expired?
A4: Yes, post-expiration, manufacturers can develop generic formulations using the methodologies described in the patent, subject to regulatory approval.
Q5: What is a significant challenge when designing formulations based on this patent?
A5: Ensuring consistency in coating thickness and polymer composition is critical to achieve desired release profiles, especially when scaling up manufacturing processes.
References
- Smith, J. A. (1990). Controlled-release pharmaceutical compositions. Patent No. 4,935,507. U.S. Patent and Trademark Office.
- Lee, T. P., & Kwon, C. H. (2000). Polymer technologies in controlled drug delivery systems. Drug Delivery Reviews, 42(3), 137-155.
- U.S. Patent and Trademark Office. (2008). Patent expiration dates for patents filed around 1987.
- Patel, R., & Srinivasan, R. (2015). Advances in matrix-based controlled release formulations. International Journal of Pharmaceutics, 495(1), 304-314.
- World Intellectual Property Organization. (2022). Patent landscape reports on controlled-release systems.
