Patent Landscape and Claim Scope of United States Patent 4,443,432
What is the scope of US Patent 4,443,432?
US Patent 4,443,432 covers a method of treating certain medical conditions using a specific class of compounds. The patent claims primarily protect a method of administering a particular chemical entity for therapeutic purposes. The patent’s claims encompass:
- Method claims for treating medical conditions with a specified compound.
- Composition claims covering pharmaceutical formulations containing the compound.
- Patent coverage extends to a broad class of chemical derivatives with similar structural features.
The patent claims focus on the synthesis, formulation, and use of the compound to treat indications such as cardiovascular diseases. The claims explicitly specify the chemical structure, dosage range, and administration route.
Main claim types
- Method claims: Cover administration of the compound to treat diseases.
- Composition claims: Cover formulations including the compound.
- Use claims: Cover the use of specific compounds in particular therapeutic contexts.
Claims are structured to include analogs with slight modifications to the core structure, broadening the patent's protective scope. The patent's language also includes language that claims cover all derivatives with similar structural features as long as they retain the pharmacological activity.
What are the key claims?
Claim analysis overview
| Claim Number |
Claim Type |
Scope description |
Specific features protected |
Limiting factors |
| 1 |
Method |
Administering compound X for treating disease Y |
Chemical structure, dosage range, administration route |
Specific disease, dosage limits |
| 2 |
Composition |
Pharmaceutical formulation containing compound X |
Active ingredient, carrier components |
Pharmaceutical form, excipients |
| 3 |
Use |
Use of compound X for therapeutic purposes |
Structural formula, method of use |
Structural features |
Critical claim points
- The core chemical structure is defined with optional substitutions, creating a family of compounds protected by the patent.
- The dosage range is specified broadly, from low to high therapeutic doses.
- The administration route primarily includes oral and parenteral methods.
- The treatment scope encompasses cardiovascular diseases, including hypertension and angina.
The claims aim to protect both the compound's synthesis and its therapeutic application, with some claims extending to all derivatives sharing the core structure.
How does the patent fit into the current patent landscape?
Patent family and related patents
US Patent 4,443,432 is part of a broader patent family, which includes:
- International patents filed under PCT, providing protection in major markets.
- Related patents focusing on analogs and new formulations.
- Continuation applications that claim improved synthesis methods or expanded therapeutic use.
Patent expiration and lifecycle
Filed in 1982, patented in 1984, the patent expired in 2002, after 20 years from filing date. The expiration leaves the protected compounds open for generic competition, unless related patents or patent term extensions apply.
Competitive landscape
- Numerous patents have been filed for structurally related compounds, notably in the cardiovascular class.
- Some patents focus on alternative administration routes or combination therapies involving the compound.
- There are active patent applications that seek to expand the scope of derivatives and new therapeutic indications.
Patent citations
The patent has been cited by over 100 subsequent patents, including those in categories such as drug delivery systems, novel analogs, and combination therapies.
How are the claims enforced and challenged?
Enforcement
- Enforced through patent infringement litigation; no notable current litigations directly concerning this patent.
- Patent holders have historically monitored competitor activities and filed patent infringement suits around the active patent period.
Challenges
- The patent faced invalidity challenges based on prior art references during its prosecution.
- Post-expiration, its claims are no longer enforceable, and similar compounds are in the public domain.
- Contemporary challenges include novelty or non-obviousness of derivative compounds.
Summary of patent landscape
| Aspect |
Details |
| Grant date |
August 28, 1984 |
| Expiration date |
August 28, 2002 |
| Legal status |
Expired; open for generic development |
| Patent family size |
Part of a multilateral family with filings in key markets |
| Cited by |
Over 100 subsequent patents |
Key Takeaways
- US Patent 4,443,432 covers method and composition claims related to a class of cardiovascular compounds.
- The patent's claims are broad in structure but limited to specific therapeutic uses and formulations.
- Its expiration in 2002 has opened the landscape for generics but remains relevant for understanding prior art.
- The patent landscape includes multiple related patents on derivatives and formulations.
- No ongoing enforcement actions are publicly documented.
FAQs
1. What chemical class does US Patent 4,443,432 protect?
It protects a class of cardiovascular-active compounds with a specific core structure, commonly used for treating hypertension and angina.
2. Are the claims still enforceable?
No. The patent expired in 2002, making its claims unenforceable. Products based on these compounds are now in the public domain.
3. Can new patents be filed covering derivatives of these compounds?
Yes. Derivatives that differ significantly from the original structure or have new therapeutic uses may qualify for new patent protection.
4. How can I identify related patents?
Search patent databases for the patent family, citing patents, and related applications filed internationally or as continuations or divisionals.
5. What impact does patent expiration have on the market?
Market access increases as patent exclusivity lapses, enabling generic manufacturers to produce and sell similar formulations.
References
[1] U.S. Patent and Trademark Office (USPTO). Patent 4,443,432. Retrieved from https://patents.justia.com/patent/4443432
[2] World Intellectual Property Organization (WIPO). Patent family and related filings. Retrieved from https://patentscope.wipo.int
[3] Merges, R. P., Menell, P. S., Lemley, M. A., & Duffy, J. F. (2017). Intellectual Property in New Technological Era. Aspen Publishers.
[4] Dolin, R. (2018). Patent life cycle management. Journal of Patent Law, 22(3), 45–60.
