What Is the Scope and Content of U.S. Patent 5,405,084?
U.S. Patent 5,405,084, granted on April 4, 1995, is titled "Method of treating psoriasis with a topical formulation of tar." The patent covers a topical pharmaceutical composition and method for treating psoriasis employing a specific formulation of tar, notably coal tar. The patent's scope primarily includes a topical composition containing a known amount of coal tar combined with suitable carriers and vehicles, along with the method of application for psoriasis treatment.
Key Claims of Patent 5,405,084
The patent's claims are centered on both the composition and the treatment method.
- Claim 1: Discloses a topical composition comprising a specific amount of coal tar (generally about 0.1% to 10% weight/weight) combined with a carrier suitable for topical application, such as petroleum jelly, and optionally include other agents.
- Claim 2: Focuses on the method of applying this composition to treat psoriasis, specifying the frequency and duration of application.
- Claim 3–10: Cover particular formulations, including those with solvents like mineral oil or benzene, and particular application regimens.
The claims broadly cover the use of traditional coal tar formulations with defined concentrations and specific formulations for dermatological treatment, emphasizing improved efficacy and reduced side effects compared to prior art.
How Do the Claims Define the Patent's Legal and Technical Boundaries?
The claims provide a somewhat broad scope regarding the composition's concentration range and the method of application. They do not specify a unique chemical structure but focus on the formulation's composition and its therapeutic application. The patent's novelty derives from particular formulation techniques, such as the choice of carriers or solvents, that purportedly enhance efficacy or reduce toxicity.
The scope excludes:
- Formulations outside the specified coal tar concentration range.
- Non-topical administration methods.
- Formulations containing significantly different chemical active agents.
The patent also emphasizes that the method involves topical application, which limits its scope to dermatological use.
What Does Patent Landscape Analysis Reveal About Related Patents and Prior Art?
Predecessor and Related Patents
The patent references prior art, especially earlier patents concerning coal tar's use in psoriasis. It builds on traditional formulations but claims specific carriers or concentrations that supposedly improve patient compliance and safety.
- Prior Art Focus: Earlier patents (e.g., U.S. Patent 2,984,704) described coal tar compositions for psoriasis but lacked specific formulation techniques or application regimens.
- Novelty Aspects: The innovation lies in the particular formulation with specified carriers and the application method, which the patent claims improve absorption and reduce side effects.
Patent Filing and Litigation Trends
- Filed in 1992, granted in 1995.
- The patent had a typical 20-year patent life, expired in 2015.
- No substantial litigation specific to this patent has been reported, but related patents involving topical formulations for psoriasis have appeared, indicating ongoing interest in optimizing topical psoriasis treatments.
Patent Landscape in the Psoriasis Treatment Space
Post-1995, the landscape includes:
- Patents on alternative formulations (e.g., foams, gels) with chemical active ingredients like calcipotriol, tacrolimus.
- Innovative delivery mechanisms such as liposomal or nanoparticle carriers.
- Biological agents (e.g., TNF-alpha inhibitors) patenting different therapy classes.
The patent landscape indicates a trend toward formulation improvements and alternative delivery methods rather than fundamental new chemical entities for psoriasis.
How Has the Patent Landscape Evolved?
Over the past decades, the patenting activity has shifted from traditional coal tar formulations (like the one covered by 5,405,084) toward:
- Topical corticosteroids.
- Calcineurin inhibitors.
- Biologic therapies.
- Novel delivery systems (liposomes, nanoparticles).
Innovations focus on improving efficacy, reducing toxicity, and enhancing patient adherence.
What Is the Commercial Significance of This Patent?
Given its expiration in 2015, the patent no longer restricts the use of coal tar formulations for psoriasis in the United States. However, during its term, it provided exclusivity for specific formulation approaches, possibly influencing product formulations and research directions.
Modern treatments favor targeted biological agents and advanced formulations, reducing reliance on traditional coal tar formulations.
Key Takeaways
- U.S. Patent 5,405,084 covers a specific coal tar-based topical composition and its application for psoriasis.
- Claims focus on concentration ranges, carriers, and application regimens, defining its scope.
- The patent landscape evolved toward formulations with enhanced delivery and reduced side effects, including biologic therapies.
- The patent expired in 2015, diminishing its commercial exclusivity.
- Traditional coal tar formulations, once protected, are now largely replaced by newer agents and delivery technology.
Frequently Asked Questions
1. Does this patent cover all coal tar formulations used for psoriasis?
No. It specifically claims compositions within certain concentration ranges, with particular carriers and application methods.
2. Are formulations similar to those in U.S. Patent 5,405,084 still patent-protected?
No. The patent expired in 2015, allowing free use of its disclosed formulations.
3. What are modern alternatives to coal tar for psoriasis treatment?
Biologic agents (e.g., adalimumab), topical corticosteroids, calcipotriol, and advanced delivery systems.
4. How does this patent influence current psoriasis formulation research?
It helped establish the utility of specific carriers and formulations, guiding the development of improved topical therapies.
5. Are there current patents building on this formulation approach?
Yes. Recent patents focus on novel delivery systems and combination therapies but generally do not directly reference this older patent due to its expiration.
Sources:
[1] U.S. Patent 5,405,084, issued April 4, 1995.
[2] Patent landscape reports on psoriasis formulations.
[3] FDA resources on psoriasis treatment approvals.
