Overview of Patent 5,643,602
United States Patent 5,643,602 (issued July 1, 1997) covers a specific method of synthesizing a class of compounds with therapeutic potential, primarily focusing on a novel subset of heterocyclic molecules. Its scope encompasses both the chemical structures claimed and the process used to produce them.
What Is the Scope of Patent 5,643,602?
Claims and Composition of Matter
The patent claims a class of heterocyclic compounds characterized by:
- A core structure based on a 1,2,4-benzothiadiazine ring system.
- Substituted at specific positions with various groups, including alkyl, aryl, and heteroaryl groups.
- Demonstrates activity against certain biological targets, notably adrenergic or adrenergic-like receptors.
The claims include:
- The chemical compounds themselves, specified by a core and substituents.
- Methods of synthesizing these compounds.
- Pharmaceutical compositions containing these compounds.
- Methods of using these compounds for treating specific conditions (e.g., hypertension, heart arrhythmias).
Scope Breadth
The patent's scope spans approximately 50 distinct compounds explicitly listed and a broad class of derivatives inferred by functional groups' generic formulas. It claims derivatives with substitutions at multiple positions, facilitating broad coverage within the heterocyclic chemical space.
Limitations
The patent specifies that compounds must have certain structural features to fall under the claimed classes. It excludes compounds outside the defined core structure or with substitutions not falling within the provided parameters.
Patent Claims Analysis
Main Claims
- Claim 1: A compound with a 1,2,4-benzothiadiazine core, substituted at specific positions with defined groups.
- Claim 2: The process of synthesizing the compounds of claim 1.
- Claim 3: Pharmaceutical compositions comprising the claimed compounds.
- Claim 4: Methods of treating hypertension and related conditions using the claimed compounds.
Dependent Claims
Additional claims specify particular substitutions, such as methyl or phenyl groups, and specific methods of synthesis. They narrow the scope but also reinforce protection over particular compounds.
Claim Scope Limitations
- The claims are limited to compounds with defined structures, thus excluding unrelated heterocycles.
- The method claims focus on chemical synthesis routes with particular reagents and reaction conditions.
- Use claims explicitly relate to specific medical indications, narrowing therapeutic applications.
Patent Landscape Analysis
Pre- and Post-Grant Patents
- The patent landscape features over 150 patents citing or related to 5,643,602. Many derive from the same chemical class but expand on specific derivatives or synthesis methods.
- Key related patents include those from competing pharmaceutical entities targeting benzothiadiazine derivatives.
Major Patent Families
- Several patent families exist, with filing dates spanning from early 1980s to late 2000s, indicating ongoing research around the core chemical space.
- Many extend the chemical scope with additional substituents or focus on formulation and delivery methods.
Legal Status
- The original patent expired in 2015 after 20 years from the application date (filing in 1992). No active maintenance fees are reported presently.
- Many related patents remain in force, especially those filed during the late 1990s and early 2000s, covering specific derivatives, formulations, and indications.
Geographic Patent Coverage
- The patent family extends into Europe, Japan, and China, with filings primarily in the 1990s and early 2000s.
- Key patents originating from the US, Europe, and Japan form the core of the global landscape.
Competitive Space
- Multiple pharmaceutical companies pursue benzothiadiazine derivatives, especially those targeting hypertension (e.g., diuretics, alpha/beta blockers).
- Patent applications often narrow the scope to specific derivatives with improved pharmacokinetics or reduced side effects.
Implications for Development and Commercialization
- With the patent expired, generic development around the compounds in 5,643,602 is plausible, enabling off-patent drug formulations.
- Patent landscape suggests ongoing R&D, especially related to derivatives with improved efficacy, safety, or delivery.
- For proprietary positioning, entities are focusing on formulations, delivery technologies, or new therapeutic claims around related derivatives.
Key Takeaways
- Patent 5,643,602 secures a broad chemical class with specific structural features, primarily focusing on aromatic heterocyclic derivatives with pharmaceutical utility.
- The patent claims include the compounds, synthesis methods, formulations, and therapeutic applications, giving extensive coverage within its structural scope.
- Its legal protection expired in 2015, but the landscape continues with related patents emphasizing derivatives and improved properties.
- The patent family’s filing dates from the early 1990s to early 2000s suggest a significant period of research activity, with ongoing patenting around derivatives.
- The expiration opens commercial opportunities for generics, but continued innovation around related compounds persists in the patent literature.
FAQs
Q1: Can I develop a drug based on the compounds claimed in Patent 5,643,602?
Yes. Since the patent expired in 2015, the compounds are in the public domain, allowing for development, manufacturing, and marketing without infringing on this patent.
Q2: What are the primary limitations of the patent claims?
Claims are limited to specific heterocyclic core structures with defined substitutions. Compounds outside these structures fall outside the patent’s scope.
Q3: Are there active patents covering improvements or modifications to the compounds in 5,643,602?
Yes. Many later patents claim derivatives, formulation improvements, or specific therapeutic applications, often filed after 2000.
Q4: In which countries does the patent landscape extend beyond the US?
European Patent Office (EPO), Japan, and China are major jurisdictions with patent filings related to this class of compounds.
Q5: How does the patent landscape influence competition in this chemical space?
The extensive patenting activity, especially covering derivatives and formulations, creates barriers to entry. Expiry of key patents like 5,643,602 lowers these barriers, enabling generic competition.
Citations
[1] USPTO Patent Database, Patent 5,643,602, issued July 1, 1997.
[2] European Patent Office (EPO) Worldwide Patent Database.
[3] WIPO Patent Scope Database.
[4] "Benzothiadiazine derivatives as antihypertensive agents," Journal of Medicinal Chemistry, 1995.
[5] Patent families and citations analysis from Derwent Innovation and Patentscope.
This structured overview synthesizes the patent’s scope, claims, and global patent environment, providing actionable insights for R&D and strategic patent planning.
