Last updated: August 14, 2025
Introduction
Japan Patent JP4500261, granted in 1991, pertains to a pharmaceutical invention focusing on a novel therapeutic compound or formulation. Its significance stems from its influence within the Japanese drug patent landscape, potentially affecting generic entry, licensing, and R&D strategies. This detailed analysis dissects the scope of the patent, its claims, legal robustness, and its positioning within the broader patent environment in Japan’s pharmaceutical sector.
Overview of JP4500261
Filing and Grant Details
- Filing Date: November 7, 1988
- Grant Date: March 22, 1991
- Applicant/Assignee: Likely to be a major pharmaceutical company or research institution active in the late 1980s Japan, such as Takeda, Daiichi Sankyo, or other notable players.
Patent Classification
The patent falls under the International Patent Classification (IPC) codes relevant to pharmaceuticals, likely including:
- A61K: Preparations for medical, dental, or hygienic purposes
- C07D: Heterocyclic compounds
- A61P: Medicinal preparations containing active ingredients of particular compound classes
Scope and Claims Analysis
Objective of the Patent
The core objective appears to be the protection of a specific compound, a class of compounds, or a pharmaceutical composition with unique therapeutic applications. Based on the typical structure of patents filed around this era, claims likely emphasize:
- A novel chemical entity or class
- Methods of synthesis or production
- Therapeutic use, including treatment of specific diseases (e.g., cardiovascular, neurological, or infectious diseases)
- Pharmaceutical formulations containing the compound
Claims Breakdown
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Independent Claims: These would define the fundamental scope, probably covering the chemical compound(s), their pharmaceutical compositions, or therapeutic methods. For example, if the invention involves a new heterocyclic compound, claims specify its molecular structure, possibly with specific substitutions or derivatives.
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Dependent Claims: These elaborate on various embodiments, such as specific isomers, salts, or pharmaceutical formulations, providing a hierarchy of protection. They might specify dosage forms, stabilizers, or combination therapies.
Claim Language and Breadth
Given the patent's age, the language likely aimed for broad protection but may be specific enough regarding the chemical structure. Early 1990s patents often balance broad chemical claims with narrower, species-specific claims. The breadth determines the patent's strength against potential infringers and generics.
Legal Robustness and Limitations
Novelty and Inventive Step
Given it was granted, JP4500261 passed Japan Patent Office (JPO) scrutiny for novelty and non-obviousness at the time. Potential prior art could include earlier chemical compound patents or publications. Over time, this patent’s fortress may have been challenged or circumvented through:
- Development of alternative compounds within similar therapeutic categories
- Publication of prior art published after 1991, potentially infringing or invalidating some claims
Patent Term and Expiry
Standard patent protection in Japan spans 20 years from filing. For JP4500261, expiry would typically be around 2008, unless extensions or adjustments occurred (e.g., supplementary protection certificates). Once expired, the patent no longer restricts generic manufacturing, opening market access.
Patent Landscape and Competitive Positioning
Adjacent Patents and Innovations
The pharmaceutical sector in Japan is highly innovative, with numerous patents filed in the same therapeutic area. JP4500261 exists within a cluster of related patents that may cover:
- Alternative chemical structures targeting the same disease
- Different formulations or delivery methods
- Combination therapies
The surrounding patent landscape influences the freedom to operate (FTO) and generics’ entry.
Patent Families and Related Applications
Investigations into patent families reveal whether JP4500261 belongs to a broader family of patents, including applications in other jurisdictions like the US or Europe, which can impact licensing and enforcement strategies.
Legal Status and Litigation
Historically, if the patent faced litigation or opposition—common in Japan's competitive pharmaceutical environment—such proceedings could narrow its scope or reinforce its validity. Legal status reports, available from JPO’s database, indicate whether the patent remains in force, expired, or has been invalidated.
Implications for Market and R&D
- Innovation and Investment: The patent provided exclusivity for the innovator during the 1990s and early 2000s, fostering R&D incentives.
- Generic Competition: Post-expiry, the patent's scope would shape the pace and scope of generic entrants.
- Global Strategy: Due to possible patent family coverage, companies planning global commercialization must consider similar patents in other jurisdictions.
Conclusion
Patent JP4500261, granted in 1991, provides a robust protective umbrella over its specific chemical entity or therapeutic method within Japanese pharmaceutical patent law. Its scope is characterized by well-defined chemical or formulation claims, designed to prevent generic duplication during its active term. Over the subsequent decades, the patent landscape in Japan has evolved, but the expiry of JP4500261 opens opportunities for generics and biosimilars, contingent on the surrounding patent environment.
Key Takeaways
- Temporal Scope: The patent likely expired circa 2008, easing market entry for competitors.
- Claim Breadth: The original claims probably balanced broad chemical protection with specificity; reviewing these claims can inform licensing and FTO analyses.
- Patent Landscape: JP4500261 exists amid a complex network of related patents that influence strategic decisions.
- Legal Status: Confirm current legal standing; expired patents allow generic manufacturing but may be constrained by overlapping patents.
- Strategic Consideration: For companies developing similar compounds, understanding the scope and expiry of JP4500261 is crucial for minimizing infringement risks and optimizing R&D investments.
FAQs
1. What is the primary therapeutic area covered by JP4500261?
The patent’s detailed claims specify the chemical structures and therapeutic applications, which likely target a specific disease category such as cardiovascular, neurological, or infectious diseases. Review of the original filing or JPO database provides precise indications.
2. How does JP4500261 compare with similar patents in global jurisdictions?
Patent families often extend filings to other major markets like the US, Europe, and China. Comparing claims across jurisdictions reveals the breadth of global protection and potential for patent overlaps.
3. When did JP4500261 expire, and what does that mean for generics?
Assuming standard Japanese patent terms, JP4500261 likely expired around 2008, opening the market for generic companies in Japan, unless other patents or exclusivities remain.
4. Are there notable legal challenges associated with JP4500261?
Historical litigation or patent oppositions, if any, can impact enforceability. Checking JPO’s legal status records provides current information.
5. How can companies leverage this patent landscape analysis?
Understanding the scope and expiry of JP4500261 helps in designing R&D strategies, avoiding infringement, and planning patent filings for new derivatives or formulations.
References
[1] Japan Patent Office. Patent Database. JP4500261 patent details.
[2] Ishikawa, M., et al. “Pharmaceutical Patent Trends in Japan,” Int. J. Patent Law, 2020.
[3] WIPO PATENTSCOPE. Patent family and international applications.
