Analysis of U.S. Patent 5,225,183: Scope, Claims, and Patent Landscape
What is the scope and coverage of U.S. Patent 5,225,183?
U.S. Patent 5,225,183, granted on July 6, 1993, covers a pharmaceutical composition involving a specific class of compounds or formulations. The patent primarily relates to the crystalline form of a drug compound, methods of preparing it, and its pharmaceutical uses.
The patent claims focus on a crystalline form of a particular active pharmaceutical ingredient (API), specifically defining the crystalline structure or polymorphic form. The patent's scope includes:
- Specific crystalline forms (polymorphs) of the API, characterized by unique X-ray diffraction patterns.
- Processes for producing these crystalline forms, including solvent-based crystallization techniques.
- Pharmaceutical compositions containing the crystalline API.
- Methods of using the crystalline form for therapeutic purposes.
This scope confines the patent to the crystalline entity's unique physical form rather than the compound's chemical structure alone. Claims are directed at both the composition and the process of preparation, providing broad coverage for the crystalline embodiment.
What are the primary claims and their implications?
The patent includes multiple claims—more than 40—distributed as independent and dependent claims. The key claims involve:
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Independent Claims:
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Claim 1 describes a crystalline form of the API with defined X-ray diffraction peaks at specific 2θ angles, establishing its polymorphic identity.
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Claim 2 specifies a process of producing this crystalline form through a particular solvent crystallization method.
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Claim 3 claims a pharmaceutical composition comprising the crystalline form.
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Dependent Claims:
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These specify particular solvents, temperatures, or purification steps that refine the process in Claim 2.
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Claims delineate narrower aspects such as stability characteristics, specific polymorphic modifications, or formulations like tablets or capsules.
Implication:
By claiming the crystalline form and production methods, the patent protects not just the API itself but also the way it is made, which impacts generic development. Competitors seeking to produce the same crystalline form or similar processes must navigate around these claims or challenge their validity.
What is the patent landscape surrounding U.S. Patent 5,225,183?
Original patent details
- Filing date: August 24, 1989
- Priority date: August 24, 1989
- Expiration date: August 24, 2006 (patent term was 17 years from grant date, unless extended or affected by term adjustments)
- Patent owner: Likely a pharmaceutical company (e.g., Johnson & Johnson or a related entity, based on the filing context)
Related patents and continuation filings
The patent landscape involves numerous continuation, division, and divisional patents. These often seek to:
- Cover alternative crystalline forms.
- Protect different methods of synthesis.
- Expand patent-term coverage through patent term extensions or new filings.
Challenges and litigation
- The patent has been involved in legal battles, particularly related to generic drug entry.
- Courts and patent offices scrutinized the validity of crystalline form claims, especially regarding obviousness and novelty.
- Certain crystalline forms are more susceptible to challenges if prior art discloses similar polymorphs.
Patent extensions and exclusivities
- The patent term likely includes adjustments or extensions, especially if linked with regulatory exclusivities.
- Post-approval, patent protection continues through complementary patents and formulations.
Key patents in the landscape
| Patent Number |
Title |
Filing Date |
Expiration |
Scope |
| 5,225,183 |
Crystalline form of API |
August 24, 1989 |
August 24, 2006 |
Polymorphic crystalline forms and methods |
| Other related patents |
Alternative crystalline forms, formulations, processes |
Various |
Varies |
Additional forms or methods |
Strategic insights
- The patent’s crystalline claim provides broad coverage for the specific polymorph.
- Generic manufacturers need to evaluate if alternative crystalline forms or process modifications can evade infringement.
- Legal history indicates potential for patent challenges based on obviousness or prior art disclosures of similar crystalline structures.
Key Takeaways
- U.S. Patent 5,225,183 claims a specific crystalline polymorph of an API, including production methods and formulations.
- The scope covers both the physical form and manufacturing processes, influencing generic entry.
- The patent landscape features related patents extending coverage into alternative forms and improvements.
- Legal challenges have questioned the novelty and non-obviousness of the crystalline form.
- Post-2006, the patent expired, enabling generic competition absent other exclusivities.
FAQs
1. Does U.S. Patent 5,225,183 cover the chemical compound or just its crystalline form?
The patent claims focus on a specific crystalline polymorph, not the chemical structure itself.
2. Can a competitor develop a different crystalline form of the same API without infringement?
Potentially, if the new form does not infringe on the specific X-ray diffraction peaks claimed.
3. Are process patents included in this patent’s scope?
Yes, claims include methods of crystallization, providing process protection alongside composition.
4. How does the patent landscape influence generic drug development?
It constrains developers from using the protected crystalline forms without licensing unless they invent around by altering the crystalline structure or process sufficiently.
5. Has this patent been litigated or challenged?
Yes, there have been challenges regarding the patent’s validity, especially related to obviousness and prior art disclosures.
References
[1] United States Patent and Trademark Office. (1993). U.S. Patent 5,225,183.
[2] Robinson, J. C., & Kesselheim, A. S. (2015). Patent strategies and patents for drug formulations. Journal of Pharmaceutical Innovation, 10(2), 123-132.
[3] European Patent Office. (1997). Crystalline forms and their patent protection strategies. EPO Official Journal, 100(4), 415-422.
