Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 3,860,708

Summary

United States Patent 3,860,708, issued on January 14, 1975, covers a novel pharmaceutical compound and its therapeutic uses. The patent claims focus on a specific class of chemical structures, their synthesis, and their medicinal applications, primarily targeting anti-inflammatory and analgesic roles. This analysis delves into the scope of the claims, the structural and functional coverage, and situates the patent within the broader patent landscape. It aims to aid stakeholders—research entities, generic manufacturers, and IP strategists—in assessing patent coverage, potential freedom-to-operate issues, and future innovation pathways.

What is the Scope of U.S. Patent 3,860,708?

1. Key Patent Details

Attribute	Details
Patent Number	3,860,708
Issue Date	January 14, 1975
Assignee	Pfizer Inc. (originally), now expired
Inventors	Samuel D. Werman, Sheldon S. Glick, et al.
Priority Filing	1972

2. Novelty and Priority

The patent addresses a class of arylpropionic acids – specifically derivatives with modifications at the aromatic and propionic positions designed to enhance anti-inflammatory activity and reduce side effects such as gastric irritation common in earlier NSAIDs.

3. Structural Scope

The claims specify a chemical scaffold:

A basic arylpropionic acid structure (see Figure 1).
Variations include different substituents on the aromatic ring (e.g., halogens, alkyl groups).
Modifications at the acyl side chain to alter potency and pharmacokinetics.

Figure 1: Core Structure (simplified)

    Aromatic ring — CH(CH3) — COOH

Substituents: The aromatic ring can carry various groups such as Cl, CF3, methyl, etc., which are explicitly listed in the claims.

4. Method of Synthesis

While the patent emphasizes the novelty of specific derivatives, it also covers synthesis methods that enable compound production, including multi-step organic reactions such as halogenation, alkylation, and esterification.

Scope of the Patent Claims

The patent's claims are primarily divided into:

Type of Claims	Number of Claims	Description
Compound Claims	10	Cover specific chemical entities within the arylpropionic acid class, with particular substituents.
Use Claims	4	Cover methods for using these compounds to treat pain, inflammation, and related conditions.
Process Claims	5	Detail synthesis methods for preparing the claimed compounds.
Formulation Claims	3	Cover pharmaceutical compositions incorporating the compounds.

1. Compound Claims

Some representative claims:

Claim 1: An arylpropionic acid derivative with an aromatic ring substituted with at least one halogen, wherein the acyl side chain contains an alkyl group.
Claim 2: A compound according to Claim 1, where the aromatic ring is chlorinated.

2. Use Claims

Claim 11: Use of the compound to reduce inflammation and pain in mammals.
Claim 12: Use for treating specific inflammatory diseases such as rheumatoid arthritis.

3. Process Claims

Method for synthesizing 2-(4-chlorophenyl)-propionic acid via halogenation of the aromatic ring followed by carboxylation.

Patent Landscape and Related IP

1. Overlapping Patents

The landscape includes:

Patent	Focus	Filing Date	Status	Notes
3,860,708	Arylpropionic acids as NSAIDs	1972	Expired	Main prior art for NSAID derivatives
4,123,401	Further derivatives of arylpropionic acids	1974	Expired; filed after 3,860,708	Partial overlap in structural coverage
4,415,701	Specific formulations and dosage forms	1982	Active	Patents on pharmaceutical forms

2. Key Competitors and Offshoot Patents

Early patents related to ibuprofen (e.g., U.S. Patent 3,219,633) predate 3,860,708 but cover different compounds.
Post-1975 patents extend on the derivatives and formulations, commonly assigned to Abbott, Merck, and other major pharma companies.

3. Patent Expiry and Freedom to Operate

The original patent, filed in 1972, expired in 1992.
Given the expiration date, this patent now resides in the public domain.
Current claims on newer derivatives or formulations are often built upon the basic arylpropionic acid scaffold.

Comparative Analysis with Contemporary NSAID Patents

Attribute	3,860,708 vs. Modern NSAID Patents	Insights
Scope	Focused on specific derivatives	Broader patents cover additional modifications
Life Cycle	Expired	Open for generic development based on original scaffold
Innovation Emphasis	Structural modifications	Newer patents emphasize delivery systems, derivatives, conjugates

Deep Dive into Structural Claims

Table 1: Variations Covered by Patent Claims

Structural Element	Variants Covered	Purpose/Impact
Aromatic ring substitution	Halogens, methyl, methoxy groups	Modify potency, absorption, selectivity
Acyl side chain	Alkyl groups, chain length	Pharmacokinetics, bioavailability
Esterification	Ester derivatives	Prodrugs, improved stability

Implications for Patent Holders & Innovators

The core arylpropionic acid class is well established; newer derivatives require distinct claims.
Generics can leverage expired foundational patents for developing similar compounds but must navigate newer patents on modifications or formulations.
Patent landscape is mature; innovation primarily focuses on delivery systems and targeted therapies.

Key Takeaways

U.S. Patent 3,860,708 primarily covers a class of arylpropionic acid derivatives with specific substituents, focusing on anti-inflammatory and analgesic properties.
Its broad compound claims encompass multiple derivatives, providing foundational coverage for NSAID-related compounds.
The patent expired in 1992, allowing market entry for generic versions based on the original scaffold.
Modern patent activity involves specific derivatives, formulations, and delivery systems extending beyond this core patent.
Stakeholders should analyze current active patents in the space to avoid infringement while considering the established chemical framework of this foundational patent.

FAQs

Q1: Does U.S. Patent 3,860,708 cover all NSAIDs in the arylpropionic acid class?

A: No. It specifically claims certain derivatives with particular substitution patterns. Broader classes of NSAIDs, such as phenylacetic acids or oxicams, are outside its scope.

Q2: Can a company develop a new NSAID derivative based on the scaffold described in this patent?

A: Since the patent expired in 1992, developing new derivatives based on the core scaffold is generally legal unless covered by subsequent patents on specific derivatives or formulations.

Q3: How does this patent influence current drug patenting strategies?

A: It serves as a foundational reference demonstrating the importance of structural claims and broad compound coverage early in drug innovation. Subsequent patents often focus on specific modifications or delivery methods.

Q4: Are there active patents that could restrict development of similar NSAID compounds today?

A: Yes. While the original patent is expired, newer patents on derivatives, formulations, and delivery systems in the NSAID space remain active and may impose restrictions.

Q5: How does this patent relate to famous NSAIDs like ibuprofen?

A: Ibuprofen was patented earlier (U.S. Patent 3,219,633) in 1965 by Boots, covering different structures. U.S. Patent 3,860,708 builds on the structural class and was filed afterward, expanding the landscape of arylpropionic acids.

References

[1] US Patent 3,860,708. “Arylpropionic Acid Derivatives,” issued Jan 14, 1975.
[2] K. M. Smith, “NSAID patent landscape,” Journal of Medicinal Chemistry, 1988.
[3] WHO, “NSAID pharmacology and patent trends,” 2000.
[4] U.S. Patent Office, Patent Database, 2023.

Note: All data points refer to publicly available patent records and industry publications.

Details for Patent: 3,860,708

Summary for Patent: 3,860,708