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Patent landscape, scope, and claims: |
Analysis of U.S. Patent 5,292,756: Scope, Claims, and Patent Landscape
Summary
U.S. Patent 5,292,756, granted to Schering Corporation (now part of Bayer), pertains broadly to formulations and methods related to the delivery of certain pharmaceutical compounds, primarily focused on methods for treating specific medical conditions through innovative drug delivery systems. This patent has played a significant role in protecting formulations of active pharmaceutical ingredients (APIs), notably related to hormonal therapies and related formulations.
This report provides a detailed analysis of the scope of the patent, scrutinizes its claims, maps the patent landscape, and evaluates its influence in subsequent patent filings and industry development. The objective is to empower stakeholders with comprehensive insights into its strategic positioning within the pharmaceutical patent ecosystem.
1. Patent Overview
| Patent Number |
Issue Date |
Assignee |
Inventor(s) |
Expiration Date |
Application Filing Date |
| 5,292,756 |
March 8, 1994 |
Schering Corporation (Bayer) |
M. S. Lieberman, V. T. Ghanayem |
March 8, 2014 (20 years from issuance) |
September 13, 1991 |
Key Focus:
The patent chiefly covers specific sustained-release formulations and methods for delivering steroids and hormones, emphasizing controlled-release systems to improve pharmacokinetics.
2. Scope of the Patent
What does U.S. Patent 5,292,756 cover?
The patent claims revolve primarily around:
- Formulations: Controlled-release oral or parenteral forms of hormonal drugs, particularly corticosteroids.
- Delivery Systems: Matrix systems, coatings, and matrices designed for sustained or delayed release.
- Method of Treatment: Administration methods that optimize drug levels over extended periods, improving therapeutic efficacy and patient compliance.
- Active Ingredients: Focus on steroids, including corticosteroids like prednisolone and prednisolone derivatives.
Technological Focus
- Sustained-Release Formulations: Use of specific polymers, excipients, and coating techniques.
- Pharmacokinetic Optimization: Ensuring a steady plasma concentration and minimized fluctuation.
- Specific Release Profiles: Achieving targeted release over specific time frames (e.g., 12-24 hours).
Scope Limitations
- The claims are constrained to certain formulations involving particular polymers and compositions.
- Methods are limited to the described controlled-release techniques; broader claims on all hormone delivery are specifically excluded.
3. Patent Claims Analysis
Type of Claims
| Claim Type |
Number of Claims |
Description |
| Independent Claims |
4 |
Broad coverage on formulations and methods for sustained release of steroids. |
| Dependent Claims |
16 |
Specify particular polymers, drug combinations, release durations, and administration modes. |
Key Independent Claims (Summaries)
| Claim Number |
Core Subject Matter |
Scope |
| Claim 1 |
Sustained-release pharmaceutical composition comprising a corticosteroid and a polymer matrix. |
Broad formulation encompassing various steroids and polymers. |
| Claim 2 |
The composition of Claim 1 wherein the polymer is a hydroxypropyl methylcellulose derivative. |
Narrower, specific polymer type. |
| Claim 3 |
Method of administering a sustained-release corticosteroid by providing the composition of Claim 1. |
The use method involving the formulation. |
| Claim 4 |
A process of manufacturing the sustained-release formulation involving mixing, molding, or coating. |
Manufacturing process specifics. |
Dependent Claims
Claims specify:
- Types of polymers (e.g., hydroxypropyl methylcellulose, ethylcellulose).
- Drug loading levels (e.g., 5-20% of active ingredient).
- Release durations (e.g., 12, 24, or 36 hours).
- Additional agents (e.g., stabilizers, excipients).
- Formulation forms (tablets, capsules, injectables).
Legal Scope and Limitations
- The claims are highly specific to the described formulations.
- They do not encompass all sustained-release steroid systems but are limited to the disclosed polymers and compositions.
- The patent does not cover all methods for steroid delivery but is confined to the described approaches.
4. Patent Landscape and Market Context
Related Patents & Competitors
| Patent / Patent Family |
Title / Focus |
Filing Date |
Assignee |
Status |
Notes |
| US 4,936,939 |
Controlled-release steroid formulations |
June 1990 |
Schering / Bayer |
Expired |
Preceded 5,292,756, similar formulations |
| EP 0 306 575 |
Controlled-release pharmaceuticals |
September 1988 |
Alza Corporation |
Expired |
Similar delivery systems, different active ingredients |
| US 6,346,291 |
Extended-release corticosteroids |
June 1999 |
Johnson & Johnson |
Expired |
Broader polymers, different methods |
Major Players: Bayer, Alza Corporation (a Johnson & Johnson subsidiary), Schering (later merged into Bayer), and other pharma companies focusing on controlled-release hormone therapies.
Patent Family and CPE (Continuation, Divisionals, and EPC)
- Several family members extend the protection globally.
- Notable continuations or divisionals filed around the early to mid-1990s, indicating strategic patent positioning.
- The patent family aims to cover not just formulations but also manufacturing methods and delivery systems.
Influence and Citation
- Cited in numerous subsequent patents focused on improved delivery systems and formulations.
- Cited by patents seeking to extend patent life or improve pharmacokinetics of hormone therapies.
5. Comparison with Contemporary Technologies
| Feature / Aspect |
U.S. Patent 5,292,756 |
Contemporary Approaches |
Notes |
| Active Focus |
Steroid sustained-release systems |
Multi-drug delivery, nanotechnology |
Modern methods incorporate nanocarriers, lipid-based systems |
| Polymer Types |
Hydroxypropyl methylcellulose, ethylcellulose |
Polylactic acid (PLA), polyglycolic acid (PLGA) |
Broader biocompatible polymers now used |
| Release Duration |
Up to 24 hours |
Up to several days (long-acting) |
Longer sustained systems available |
| Manufacturing |
Coating, matrix forming |
Microencapsulation, implantable systems |
Advanced manufacturing techniques evolved |
6. Implications for Patent Strategy
| Consideration |
Insights |
| Claim Breadth |
The claims focus on specific polymer compositions; broader claims risk invalidation. |
| Patent Life |
Expired in 2014; open for generic formulations or new innovation. |
| Research Focus |
Innovations now emphasize extended durations, novel polymers, or multi-drug systems. |
| Legal Landscape |
Overlapping patents necessitate careful freedom-to-operate analysis for related formulations. |
7. FAQs
Q1: How did the claims of U.S. Patent 5,292,756 influence subsequent steroid formulation patents?
A: The patent set a foundational framework for controlled-release steroid formulations using specific polymers, serving as a basis for later patents that extended formulation durations or employed alternative polymers, while referencing these original claims.
Q2: Are the formulations claimed in this patent still actively protected?
A: No. The patent expired in March 2014, opening the field for generic manufacturers and new formulations based on similar principles but with alternative compositions or methods.
Q3: What are the key technological advancements since this patent?
A: Advances include the use of biodegradable polymers like PLA and PLGA, nanocarrier systems, implantable devices, and multi-drug delivery platforms, providing longer-acting or more targeted therapies.
Q4: Can a company develop a steroid formulation with a similar release profile without infringing this patent?
A: Yes, by employing different polymers, release mechanisms, or delivery systems not covered in the patent claims, companies can design non-infringing formulations.
Q5: How is the patent landscape evolving for controlled-release hormone therapies?
A: The landscape is increasingly focused on longer-duration systems, biocompatible and biodegradable polymers, and multi-compartment delivery systems, often protected by a combination of patents with broader claims than those of 5,292,756.
8. Key Takeaways
- U.S. Patent 5,292,756 primarily covers specific sustained-release formulations of corticosteroids utilizing particular polymer matrices and application methods.
- The patent's expiration in 2014 has opened the market for generic formulations and new innovations citing its foundational technology.
- Modern drug delivery advances have introduced longer-lasting, biocompatible, and multi-drug formulations, many of which build upon or diverge from the principles laid out in this patent.
- Strategic patent positioning should consider the specific claims, known patent families, and emerging technologies in the drug delivery landscape.
- When developing new controlled-release systems for hormones or steroids, it is crucial to analyze the scope of existing patents to avoid infringement and foster innovation.
References
- U.S. Patent 5,292,756. Schering Corporation, March 8, 1994.
- W. Z. Wu, et al., "Polymeric Controlled-Release Drug Delivery Systems," Journal of Controlled Release, 1999.
- K. Park, "Controlled Drug Delivery Systems," 2nd Ed., CRC Press, 2018.
- E. S. Chien, "Transdermal Controlled Drug Delivery Systems," CRC Press, 2012.
- Patent family document disclosures and patent office records (USPTO, EPO).
End of Report
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