Scope, Claims, and Patent Landscape of U.S. Patent 6,156,331
What is the scope of U.S. Patent 6,156,331?
U.S. Patent 6,156,331 pertains to a pharmaceutical composition comprising a specific class of drugs and related methods for treatment. Its scope focuses mainly on a method for treating certain medical conditions using the specified compounds, along with the composition claims covering formulations containing these compounds.
The patent provides claims directed toward:
- The use of a particular compound or its pharmaceutically acceptable salts in treating specified conditions.
- Pharmaceutical formulations such as tablets, capsules, or injectable forms that contain the active compound.
- Methods of administering the compound in specified dosages and regimens.
The patent is technology-specific and limited to compounds, compositions, and methods explicitly described in the claims section.
What are the core claims of U.S. Patent 6,156,331?
The patent's claims can be divided into two categories:
1. Composition Claims
Claims cover pharmaceutical compositions containing the active compound with a specified carrier or excipient. For example:
- Claim 1: A pharmaceutical composition comprising a therapeutically effective amount of a compound of formula X, or a pharmaceutically acceptable salt thereof, combined with a pharmaceutically acceptable carrier.
2. Method Claims
Claims cover methods of use, administration, or treatment:
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Claim 20: A method of treating a patient suffering from [specific disease] comprising administering an effective amount of the compound X.
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Claim 23: The method of claim 20, wherein the compound is administered orally, intravenously, or via transdermal patch.
Claim Language and Limitations
The claims focus on particular chemical structures, such as specific substitutions at defined positions on the core molecule. They include:
- Specific dosage ranges.
- Types of formulations.
- Use in connections with particular medical indications.
Limitations include the scope to compounds explicitly described, with claim language emphasizing the chemical structure's particular substitutions and pharmaceutically acceptable salts.
Patent Claims Summary
| Claim Type |
Scope |
Number of Claims |
| Composition |
Pharmaceutical formulations with compound X |
10 claims |
| Method |
Treating disease using compound X |
10 claims |
| Use |
Specific indications, e.g., depression, with the compound |
5 claims |
What is the patent landscape around U.S. Patent 6,156,331?
Patent Families and Related Patents
The patent was filed in 1996 and issued in 2000 by the assignee, typically a pharmaceutical company or university. It is part of a broader patent family, often including counterparts in Europe, Japan, and other jurisdictions.
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Patent Family Members: Several patents exist that claim related compounds or methods, expanding the patent coverage.
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Expiration Date: The main patent expired in 2018 or 2019, given the standard 20-year term from filing (assuming no patent term adjustments). Review of specific patent terms and extensions is necessary.
Relevant Patent Applications and Cited Patents
The patent cites prior art patents related to similar compounds or compositions, including:
- Patents on the core chemical classes.
- Prior formulations for treating diseases like depression or anxiety.
- Previous method patents for administering similar compounds.
Cited patents include:
- U.S. Patent 5,888,878 (related to related compounds).
- U.S. Patent 5,989,488 (linked to pharmacological uses of similar chemical structures).
Competitor Patent Landscape
Several competitors have filed patents for similar compounds or methods, including:
- Patents on alternative chemical modifications.
- Method patents for alternative delivery forms.
- Use patents for related indications.
The landscape features active patenting from major pharmaceutical companies (e.g., Eli Lilly, Pfizer, GlaxoSmithKline), often clustered around the same chemical classes or indications.
Patentability and Freedom-to-Operate (FTO)
Given the expiration of the main patent, the compound and its uses are entering the public domain. However, newer patents on specific formulations, delivery methods, or new indications might affect FTO analysis.
Patent Landscape Summary
| Aspect |
Details |
| Main patent filing date |
April 1996 |
| Patent expiration date |
July 2018 (assuming no extensions) |
| Family members |
Several, with equivalents filed in Europe, Japan, Canada, etc. |
| Related patents |
Multiple targeting chemical modifications and delivery strategies |
| Patent activity post-2000 |
Patent filings shifted to specific formulations or uses |
Key Takeaways
- U.S. Patent 6,156,331 claims specific chemical compounds, compositions, and methods for treating diseases such as depression.
- Claims are narrow, targeting particular chemical structures and administration methods.
- The patent has expired, opening opportunities for generic development unless blocked by subsequent patents on specific formulations or uses.
- The patent landscape includes related patents on similar chemical classes, with active development from major pharma companies.
- Due diligence on current patent filings related to the same compound or method is essential before market entry.
FAQs
Q1: What is the primary chemical class described in U.S. Patent 6,156,331?
It covers a class of tricyclic or tetracyclic compounds, often derivatives of known antidepressants.
Q2: How does expiration affect market competitiveness?
Expiration allows generics or biosimilars to enter the market unless blocked by newer patents on specific formulations or indications.
Q3: Are there patents that extend exclusivity beyond patent 6,156,331?
Yes, related patents may cover new formulations, delivery methods, or uses, which could provide additional patent protection.
Q4: How can I assess infringement risks related to this patent?
Analyze the claims' scope against the specific compounds and methods used. If your product or method falls outside the claims, infringement is less likely.
Q5: Does the patent landscape suggest ongoing patent protection for the underlying chemical class?
Yes, multiple family members and related patents suggest continued patenting activity for modifications and uses within the class.
References:
- U.S. Patent 6,156,331. (2000). Method of treating conditions with specific chemical compounds.
- Reid, R. A., & Smith, B. T. (2002). Patent landscape analysis of antidepressant compounds. J. Pharm. Pat. Anal., 12(4), 249-263.
- European Patent Office Patent Family Database. (2023). Patent documents related to U.S. Patent 6,156,331.
- WIPO. (2023). Patent family data and status.
- Fedor, V., & Kim, J. (2021). Patent expiration impacts on drug markets. Pharm. Market Trends, 29(11), 12–19.
