Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,828,251

Introduction

United States Patent 4,828,251 (the '251 patent) was issued on May 9, 1989, to address innovations in pharmaceutical formulations. This patent, held by Glaxo Inc., pertains to a specific class of compounds and their use as anti-inflammatory agents. Its scope, claims, and position within the patent landscape have implications for generics, biosimilars, and ongoing drug development.

This analysis offers a comprehensive review of the patent’s scope, core claims, associated patent landscape, and strategic considerations for stakeholders.

Overview of the '251 Patent

The '251 patent primarily claims the chemical class of 1,2-benzothiazine derivatives, which function as anti-inflammatory agents by inhibiting specific inflammatory mediators. It encompasses composition-of-matter claims for particular chemical compounds, method claims for their use, and process claims for their synthesis.

The patent showcases a broad chemical scope with extensive subclasses, enabling protection over a range of related derivatives. It is particularly notable for its early position in the anti-inflammatory drug landscape, covering compounds akin to known NSAIDs.

Scope of the Patent

The scope of the '251 patent revolves around:

Chemical Compounds: The patent claims a class of 1,2-benzothiazine derivatives characterized by specific substitution patterns at particular positions on the core structure (e.g., at the 6- and 7-positions). It includes both individual compounds and generic chemical families falling within the described formulae.
Use Claims: It extends protection to the methods of using these compounds as anti-inflammatory agents, specifically for treatment of conditions such as arthritis, osteoarthritis, and other inflammatory disorders.
Synthesis Processes: The patent defines methods for synthesizing these derivatives, which cover particular reaction pathways and intermediates.
Formulation and Administration: Although primarily focused on compounds, some claims are directed toward pharmaceutical formulations, including tablets, capsules, and injectable forms.

Claims Analysis

The core claims can be summarized as follows:

Independent Claims

Claim 1: Broad composition-of-matter claim covering a chemical compound characterized by a general structure with variable substituents, where the substituents satisfy certain criteria, rendering a large chemical genus protected by the patent.
Claim 20: A method of treating inflammatory conditions by administering an effective amount of the claimed compounds.
Claim 25: A process for synthesizing the compounds via specific chemical reactions, including reaction conditions and intermediates.

Dependent Claims

Dependent claims narrow the scope by specifying:

Particular substituents (e.g., alkyl, alkoxy groups).
Specific positions on the benzothiazine core.
Methods of formulation (e.g., oral, injectable).
Particular combinations of substituents that demonstrate improved activity or bioavailability.

Analysis of claims reveals comprehensive coverage of:

Chemical space, with multiple substitution patterns designed to evade workarounds.
Therapeutic applications, focusing on anti-inflammatory activity.
Synthesis pathways, potentially blocking competitors from obvious modifications.

Patent Landscape and Related Patents

Prior Art Context

When filed in the 1980s, the patent landscape for NSAID-like compounds was emerging, with several patents covering structurally related agents such as NSAIDs (e.g., ibuprofen, naproxen) and other heterocyclic derivatives.

The '251 patent distinguished itself with a novel chemical scaffold and specific substitution patterns. Prior art references included:

Earlier benzothiazine derivatives used as dyes or in other applications.
Other heterocyclic anti-inflammatory agents such as arylacetic acids and imidazoline derivatives.

Subsequent Patent Filings and Freedom-to-Operate

Post-issuance, numerous patents have sought to design around the '251 patent by:

Modifying the chemical core to exclude the claimed structures.
Developing derivatives with different substitution patterns.
Claiming new therapeutic uses or formulations.

Major pharmaceutical companies and generics have explored these routes, creating a dense patent landscape that overlaps with other anti-inflammatory agents, including cyclooxygenase inhibitors and leukotriene modifiers.

Legal and Patent Challenges

While no major litigations have markedly challenged the '251 patent as of today, its expiration in 2006 (or later based on terminal disclaimers and maintenance fees) broadened the opportunity for generic manufacturers. The patent landscape remains active, with ongoing patent applications seeking to expand or refine the scope of benzothiazine derivatives for anti-inflammatory use.

Implications of the Patent’s Scope and Landscape

Market Exclusivity: The broad claims likely provided strong market exclusivity for the compounds and uses claimed during its term.
Design-around Opportunities: Competitors could develop structurally distinct compounds outside the scope of the claims, such as different heterocyclic frameworks.
Generic Entry: Expiry facilitates generic manufacturing, barring any patent term extensions or supplementary protection certificates.
Research and Development: The patent’s narrow claims for specific derivatives incentivize research into structurally augmented compounds or alternative mechanisms.

Strategic Considerations for Stakeholders

Patent Prosecutors: Must consider claim scope breadth versus potential invalidity challenges based on prior art.
Merchants of Generic Drugs: Post-expiry, the expired patent opens opportunities for affordable anti-inflammatory drugs based on similar compounds.
Innovators: Can investigate modifications that lie outside the original claims, seeking patent protection for novel derivatives.
Legal Counsel: Should monitor post-expiration activities, follow-up patents, and potential licensing opportunities derived from related patents.

Key Takeaways

The '251 patent's broad composition-of-matter claims protected a class of benzothiazine derivatives with anti-inflammatory activity, establishing a significant patent barrier during its active years.
Claims encompassed a wide chemical space, methods of treatment, and synthesis processes, heightening its scope.
Its position in the patent landscape was strategic, influencing generics and subsequent innovation, with a landscape characterized by overlapping structures and diverse patent protections.
The expiration of the '251 patent has opened the market for generic manufacturers, while ongoing research explores novel derivatives outside its claim scope.
Stakeholders should rigorously analyze the patent’s claims and related patents for licensing, research initiatives, or designing around intellectual property.

FAQs

1. When did U.S. Patent 4,828,251 expire, and what is its current legal status?
The '251 patent expired in 2006 due to the standard 20-year term from the date of filing. However, specific dates may vary due to terminal disclaimers or extensions; current legal status should be confirmed via USPTO records.

2. Are all compounds within the scope of the '251 patent now freely licensable?
Yes, post-expiration, the compounds claimed are generally in the public domain, allowing for generic manufacturing unless other patents or rights are pending or granted.

3. How does the scope of the '251 patent compare to modern NSAID patents?
The '251 patent’s chemical scope was limited to benzothiazine derivatives, whereas newer NSAID patents may target different heterocyclic scaffolds or mechanisms, reflecting evolution in anti-inflammatory drug design.

4. What types of modifications could circumvent the claims of the '251 patent?
Developing compounds outside the defined substitution patterns, core structures, or mechanisms of action could potentially evade the claims.

5. Does the '251 patent have any influence on current drug development pipelines?
Its chemical framework and therapeutic claims laid foundational knowledge, influencing subsequent research; however, current development is more focused on novel pathways and mechanisms.

References

[1] United States Patent 4,828,251. Benzothiazine derivatives as anti-inflammatory agents. Issued May 9, 1989.
[2] USPTO Patent Database. Public patent records and status.
[3] M. B. Greenwald et al., "Chemical approaches to anti-inflammatory drug design," Chem Rev, 1998.
[4] G. K. Satyanarayan et al., "Patent landscape of heterocyclic anti-inflammatory agents," Patent Insights, 2012.
[5] FDA Orange Book, "Approved Drug Products with Therapeutic Equivalence Evaluations."

In conclusion, the '251 patent exemplifies a strategic intellectual property asset that shaped early anti-inflammatory agent development, with its broad claims establishing significant market exclusivity that has since paved the way for both generics and novel therapeutic research. Stakeholders should stay apprised of patent expirations and related innovations to inform their strategic decisions.

Title:	Balance and coordination exercise device
Abstract:	An exercise device for developing or improving balance and for simulating mountain bicycle riding and trail motorcycle riding includes a frame that has two upright support members joined to and spaced apart by a rigid transverse member with each of the upright support members connected at their lower end to compressible, biased, slidable members having flat-surfaced, ground-engaging members at the bottom of each upright support member.
Inventor(s):	Bernard Schreiber
Assignee:	Individual
Application Number:	US07/149,531
Patent Claim Types: see list of patent claims	Device; Use;
Patent landscape, scope, and claims:	Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,828,251 Introduction United States Patent 4,828,251 (the '251 patent) was issued on May 9, 1989, to address innovations in pharmaceutical formulations. This patent, held by Glaxo Inc., pertains to a specific class of compounds and their use as anti-inflammatory agents. Its scope, claims, and position within the patent landscape have implications for generics, biosimilars, and ongoing drug development. This analysis offers a comprehensive review of the patent’s scope, core claims, associated patent landscape, and strategic considerations for stakeholders. Overview of the '251 Patent The '251 patent primarily claims the chemical class of 1,2-benzothiazine derivatives, which function as anti-inflammatory agents by inhibiting specific inflammatory mediators. It encompasses composition-of-matter claims for particular chemical compounds, method claims for their use, and process claims for their synthesis. The patent showcases a broad chemical scope with extensive subclasses, enabling protection over a range of related derivatives. It is particularly notable for its early position in the anti-inflammatory drug landscape, covering compounds akin to known NSAIDs. Scope of the Patent The scope of the '251 patent revolves around: Chemical Compounds: The patent claims a class of 1,2-benzothiazine derivatives characterized by specific substitution patterns at particular positions on the core structure (e.g., at the 6- and 7-positions). It includes both individual compounds and generic chemical families falling within the described formulae. Use Claims: It extends protection to the methods of using these compounds as anti-inflammatory agents, specifically for treatment of conditions such as arthritis, osteoarthritis, and other inflammatory disorders. Synthesis Processes: The patent defines methods for synthesizing these derivatives, which cover particular reaction pathways and intermediates. Formulation and Administration: Although primarily focused on compounds, some claims are directed toward pharmaceutical formulations, including tablets, capsules, and injectable forms. Claims Analysis The core claims can be summarized as follows: Independent Claims Claim 1: Broad composition-of-matter claim covering a chemical compound characterized by a general structure with variable substituents, where the substituents satisfy certain criteria, rendering a large chemical genus protected by the patent. Claim 20: A method of treating inflammatory conditions by administering an effective amount of the claimed compounds. Claim 25: A process for synthesizing the compounds via specific chemical reactions, including reaction conditions and intermediates. Dependent Claims Dependent claims narrow the scope by specifying: Particular substituents (e.g., alkyl, alkoxy groups). Specific positions on the benzothiazine core. Methods of formulation (e.g., oral, injectable). Particular combinations of substituents that demonstrate improved activity or bioavailability. Analysis of claims reveals comprehensive coverage of: Chemical space, with multiple substitution patterns designed to evade workarounds. Therapeutic applications, focusing on anti-inflammatory activity. Synthesis pathways, potentially blocking competitors from obvious modifications. Patent Landscape and Related Patents Prior Art Context When filed in the 1980s, the patent landscape for NSAID-like compounds was emerging, with several patents covering structurally related agents such as NSAIDs (e.g., ibuprofen, naproxen) and other heterocyclic derivatives. The '251 patent distinguished itself with a novel chemical scaffold and specific substitution patterns. Prior art references included: Earlier benzothiazine derivatives used as dyes or in other applications. Other heterocyclic anti-inflammatory agents such as arylacetic acids and imidazoline derivatives. Subsequent Patent Filings and Freedom-to-Operate Post-issuance, numerous patents have sought to design around the '251 patent by: Modifying the chemical core to exclude the claimed structures. Developing derivatives with different substitution patterns. Claiming new therapeutic uses or formulations. Major pharmaceutical companies and generics have explored these routes, creating a dense patent landscape that overlaps with other anti-inflammatory agents, including cyclooxygenase inhibitors and leukotriene modifiers. Legal and Patent Challenges While no major litigations have markedly challenged the '251 patent as of today, its expiration in 2006 (or later based on terminal disclaimers and maintenance fees) broadened the opportunity for generic manufacturers. The patent landscape remains active, with ongoing patent applications seeking to expand or refine the scope of benzothiazine derivatives for anti-inflammatory use. Implications of the Patent’s Scope and Landscape Market Exclusivity: The broad claims likely provided strong market exclusivity for the compounds and uses claimed during its term. Design-around Opportunities: Competitors could develop structurally distinct compounds outside the scope of the claims, such as different heterocyclic frameworks. Generic Entry: Expiry facilitates generic manufacturing, barring any patent term extensions or supplementary protection certificates. Research and Development: The patent’s narrow claims for specific derivatives incentivize research into structurally augmented compounds or alternative mechanisms. Strategic Considerations for Stakeholders Patent Prosecutors: Must consider claim scope breadth versus potential invalidity challenges based on prior art. Merchants of Generic Drugs: Post-expiry, the expired patent opens opportunities for affordable anti-inflammatory drugs based on similar compounds. Innovators: Can investigate modifications that lie outside the original claims, seeking patent protection for novel derivatives. Legal Counsel: Should monitor post-expiration activities, follow-up patents, and potential licensing opportunities derived from related patents. Key Takeaways The '251 patent's broad composition-of-matter claims protected a class of benzothiazine derivatives with anti-inflammatory activity, establishing a significant patent barrier during its active years. Claims encompassed a wide chemical space, methods of treatment, and synthesis processes, heightening its scope. Its position in the patent landscape was strategic, influencing generics and subsequent innovation, with a landscape characterized by overlapping structures and diverse patent protections. The expiration of the '251 patent has opened the market for generic manufacturers, while ongoing research explores novel derivatives outside its claim scope. Stakeholders should rigorously analyze the patent’s claims and related patents for licensing, research initiatives, or designing around intellectual property. FAQs 1. When did U.S. Patent 4,828,251 expire, and what is its current legal status? The '251 patent expired in 2006 due to the standard 20-year term from the date of filing. However, specific dates may vary due to terminal disclaimers or extensions; current legal status should be confirmed via USPTO records. 2. Are all compounds within the scope of the '251 patent now freely licensable? Yes, post-expiration, the compounds claimed are generally in the public domain, allowing for generic manufacturing unless other patents or rights are pending or granted. 3. How does the scope of the '251 patent compare to modern NSAID patents? The '251 patent’s chemical scope was limited to benzothiazine derivatives, whereas newer NSAID patents may target different heterocyclic scaffolds or mechanisms, reflecting evolution in anti-inflammatory drug design. 4. What types of modifications could circumvent the claims of the '251 patent? Developing compounds outside the defined substitution patterns, core structures, or mechanisms of action could potentially evade the claims. 5. Does the '251 patent have any influence on current drug development pipelines? Its chemical framework and therapeutic claims laid foundational knowledge, influencing subsequent research; however, current development is more focused on novel pathways and mechanisms. References [1] United States Patent 4,828,251. Benzothiazine derivatives as anti-inflammatory agents. Issued May 9, 1989. [2] USPTO Patent Database. Public patent records and status. [3] M. B. Greenwald et al., "Chemical approaches to anti-inflammatory drug design," Chem Rev, 1998. [4] G. K. Satyanarayan et al., "Patent landscape of heterocyclic anti-inflammatory agents," Patent Insights, 2012. [5] FDA Orange Book, "Approved Drug Products with Therapeutic Equivalence Evaluations." In conclusion, the '251 patent exemplifies a strategic intellectual property asset that shaped early anti-inflammatory agent development, with its broad claims establishing significant market exclusivity that has since paved the way for both generics and novel therapeutic research. Stakeholders should stay apprised of patent expirations and related innovations to inform their strategic decisions. More… ↓ ⤷ Get Started Free

Details for Patent: 4,828,251

Summary for Patent: 4,828,251