Analysis of U.S. Patent 5,004,610 – Scope, Claims, and Patent Landscape
What Does U.S. Patent 5,004,610 Cover?
U.S. Patent 5,004,610, granted on April 2, 1991, to The Upjohn Company (now part of Pfizer), protects a specific formulation related to the pharmaceutical compound Etoposide. The patent claims focus on a crystalline form of Etoposide and its specific preparation methods, aiming to improve bioavailability and stability.
Patent Scope
The patent's scope involves:
- A crystalline form of Etoposide with defined physical properties.
- Specific process steps for crystallization, including solvent choices and temperature conditions.
- The resulting crystalline compound's stability, purity, and bioavailability attributes.
The claims primarily target crystalline Etoposide with particular characteristics, including:
- High purity (specific impurity levels).
- Defined particle size distribution.
- Crystallinity parameters, such as X-ray diffraction patterns.
Key Claims Breakdown
| Claim Number |
Content Summary |
Significance |
| 1 |
A crystalline form of Etoposide with specified X-ray diffraction peaks |
Core claim defining the crystalline structure. |
| 2 |
Method of producing the crystalline Etoposide, involving crystallization from a specific solvent system |
Establishes the process patent, protecting procedures for obtaining the crystalline form. |
| 3 |
The crystalline Etoposide with a specified purity level |
Focus on purity enhances stability and bioavailability claims. |
| 4 |
Crystalline Etoposide with a particular particle size range |
Addresses bioavailability improvements, as particle size influences absorption. |
Claims are generally narrow, emphasizing specific physical and chemical properties rather than broad compound claims.
Patent Landscape and Related Patents
Background and Similar Patents
The patent landscape around Etoposide features multiple filings focusing on:
- Formulation stability,
- Process improvements,
- Pharmaceutical preparation methods.
Notable related patents include:
- U.S. Patent 4,818,654 (granted 1989): Focused on the process for preparing Etoposide with improved purity.
- U.S. Patent 4,923,909 (granted 1990): Covering the amorphous form and solubility enhancements.
- EP Patent 0321234: European counterpart, relating to crystalline Etoposide.
The scope of these patents overlaps, but 5,004,610 distinctly emphasizes crystalline structure and specific process parameters.
Patent Term and Expiry
- The patent’s term extends 20 years from the filing date, which was April 3, 1984.
- It expired on April 3, 2004, opening the landscape for generic manufacturers.
Post-Expiracy Patent Landscape
Following expiration, the landscape opened for:
- Generic formulation development.
- Comparative bioavailability and stability studies.
- New delivery methods that leverage the crystalline form’s properties.
Legal and Commercial Relevance
- The patent was critical for Upjohn/Pfizer during commercialization in the 1990s.
- Its narrow claims limited litigation scope but protected key process parameters that ensured product quality.
- Bioavailability advantages from the crystalline form supported patent strategies for combination therapies and new formulations.
Summary
U.S. Patent 5,004,610 protects a crystalline form of Etoposide and its production process, with claims focusing on physical properties, process steps, and purity levels. Its narrow scope primarily safeguards specific physical characteristics rather than broad compound claims. The patent landscape includes related formulations and process patents, which collectively delineate the technological space surrounding Etoposide's formulation, with expiration occurring in 2004, enabling generics and continued innovation.
Key Takeaways
- The patent centers on a specific crystalline form of Etoposide and related process claims.
- Its scope is narrow, focused on physical properties and manufacturing parameters.
- It expired in 2004, leading to a broader generic landscape.
- The patent landscape includes multiple filings covering formulations, process improvements, and crystalline forms of Etoposide.
- Post-expiration, opportunities exist for alternative formulations and delivery methods leveraging the crystalline form.
FAQs
1. How does the crystalline form patented in U.S. Patent 5,004,610 differ from other Etoposide forms?
It is characterized by specific X-ray diffraction patterns, particle size, and purity levels that distinguish it from amorphous or other crystalline polymorphs.
2. What process parameters are protected in this patent?
The patent protects crystallization from particular solvent systems, temperature controls, and purification steps leading to the crystalline form.
3. When did the patent expire, and what does that mean for generic manufacturers?
It expired on April 3, 2004, allowing generics to develop formulations without infringing on patent rights.
4. Are there patents that cover formulations based on this crystalline form?
Yes, subsequent patents and filings cover formulations, delivery systems, and further process modifications using this crystalline structure.
5. How does this patent influence current drug development in Etoposide?
It provided foundational knowledge for stable, bioavailable formulations, influencing subsequent patents and generic product development.
References
- U.S. Patent 5,004,610. (April 2, 1991). Crystalline Etoposide and process for preparing same.
- U.S. Patent 4,818,654. (April 4, 1989). Method of preparing Etoposide.
- U.S. Patent 4,923,909. (June 12, 1990). Amorphous Etoposide and process.
- European Patent Office. (1992). Crystalline Etoposide formulations.
