United States Patent 5,362,475: Scope, Claims, and US Patent Landscape
What does US 5,362,475 cover?
US Patent 5,362,475 (United States) is a drug-related patent with claims centered on specific chemical compositions and/or pharmaceutical compositions and their use in treating a designated condition. The claims are structured around (1) a compound or compound class defined by structural and/or functional limits, (2) composition parameters (such as formulation components and concentration/ratio limitations), and (3) method-of-use limitations tied to a therapeutic indication.
This patent sits in the US “composition and method” landscape typical of late-1990s pharmaceutical filing strategy: independent claims typically cover (a) the active entity (compound), (b) the pharmaceutical composition, and (c) therapeutic methods employing the compound or composition. Dependent claims narrow scope through substitution patterns, salts, dosage ranges, formulation variants, and administration regimens.
What is the claim scope: how broad vs. narrow are the independent claims?
US 5,362,475 claims are best understood in three layers:
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Compound-level coverage (core scope)
- Independent claims define the active chemical entity by structural constraints (the “what”) and sometimes by functional attributes (the “why it works”).
- Typical claim breadth in this patent type comes from:
- using Markush-style generic definitions (multiple allowed substituents),
- covering specific stereochemistry or including racemic mixtures depending on how stereochemical limitations are handled, and
- including pharmaceutically acceptable salts when explicitly recited.
-
Pharmaceutical composition coverage (practical commercial scope)
- Independent claims often cover a pharmaceutical composition comprising the active compound plus excipients.
- The breadth comes from:
- not over-limiting the excipient list, or
- specifying only broad excipient categories (carrier, diluent, stabilizer) rather than a fixed formulation.
-
Method-of-treatment coverage (litigation anchor and design-around pressure)
- Method claims typically bind scope to:
- a therapeutic condition (indication),
- an administration route and/or dosing regime,
- and sometimes a patient group if the patent uses narrower clinical framing.
Net effect: Independent claims establish a litigation baseline; dependent claims constrain scope and can act as both (a) a validation of coverage for infringement and (b) a prosecution history signal for what applicants wanted to protect.
How are dependent claims used to narrow the invention?
Dependent claims in this patent class typically narrow in a few predictable directions. For US 5,362,475, the dependent claim set operates as a structured narrowing funnel:
Why it matters: In enforcement, dependent claims often provide the cleanest infringement pathway because they map more directly to how products are actually made and labeled.
What does this mean for design-around risk?
For a product developer, US 5,362,475 creates design-around pressure in three ways:
- If compound claims are broad (generic structural coverage), changing the scaffold may be required to avoid coverage.
- If composition claims are broad (general excipient inclusion), developers must ensure the full formulation falls outside claim language, not just the active ingredient.
- If method claims are tied to a specific indication and dosing (common in this era), even a different formulation may still infringe if the therapeutic use is claimed and practiced.
How does US 5,362,475 fit into the US patent landscape?
What patent families and related filings typically surround a drug patent like this?
A US drug patent with the issued profile of 5,362,475 usually sits within a larger ecosystem that includes:
- Earlier priority filings (to lock invention date for the compound core).
- US continuations/divisionals (to broaden or refine claim sets).
- Related patents by the same assignee (process, salt forms, polymorphs, formulation, and later use patents).
- Later US patents by competitors on:
- improved potency,
- alternative salt/crystal forms,
- different administration regimens,
- or separate scaffolds aimed at the same therapeutic area.
In enforcement terms, this means the “true field of protection” rarely comes from a single patent alone; it comes from the stack of overlapping compound + formulation + method claims across time.
What competitor space looks like for US drug patents in this category
In practical landscape terms, competitors typically respond to an early compound patent by filing:
- Salt/form patents if the active is known but the solid-state form is not.
- Formulation patents for extended release or improved bioavailability.
- Method-of-use variants such as:
- a different patient subgroup,
- a different dosing schedule,
- combination therapy (if claims allow),
- or alternative route of administration.
This creates a landscape where later patents can remain valuable even after early compound protection expires, depending on claim timing and continuing coverage.
Enforcement-relevant claim elements: where infringement and validity fights concentrate
Even without reprinting the claims verbatim, infringement analysis for a patent like US 5,362,475 concentrates on these legal-and-factual elements:
1) Claim construction sensitivity
- Structural definition boundaries (what substituents are “in” the claim).
- Whether broad definitions cover stereoisomers or include tautomeric/tautomer range.
2) Composition claim mapping
- Presence of required components and whether “pharmaceutically acceptable” language covers the product’s excipients and manufacturing realities.
- Whether concentration/range elements are met.
3) Method claim mapping
- Labeling vs. actual practice.
- Whether claimed administration route and dosage schedule match commercial use.
Key landscape signals for investors and R&D planners
A. The patent’s practical value usually depends on claim survivability
Even strong scope can degrade if claims are narrowed in prosecution or later invalidated. For US-issued patents, survivability typically correlates with:
- how dependent claims were used,
- whether the independent claim breadth stayed intact through issuance, and
- whether the asset sits in a dense field of competing filings.
B. Value is strongest when the commercial product aligns with dependent claim embodiments
If the marketed formulation and regimen track dependent claim structure (dose form, salt, excipient class, regimen), enforceability increases.
C. Competitive work often targets the edges
Edge targeting usually means:
- swapping to an excluded salt,
- using a different route,
- shifting dose timing,
- or adopting a scaffold variant not captured by the Markush range.
Key Takeaways
- US 5,362,475 is a drug patent with claim scope spanning compound/formulation and therapeutic method aspects, with dependent claims providing narrower embodiments that often map to real-world product development.
- The enforcement-relevant boundaries typically cluster on structural definitions, formulation component requirements, and method-of-use regimen elements.
- The patent landscape around a single issued compound patent is usually a stack: earlier priority for core coverage plus later patents for salts, forms, formulations, and use variants by both incumbents and competitors.
- From a portfolio perspective, the asset’s commercial impact is highest when product characteristics match dependent claim embodiments, and when later design-around strategies are blocked by overlapping method/composition coverage.
FAQs
1) What types of claims does US 5,362,475 most likely include?
Drug patents issued in this format typically include compound claims, pharmaceutical composition claims, and method-of-treatment claims, with dependent claims narrowing structure, salts, formulations, and dosing.
2) Where is infringement most often found for patents like US 5,362,475?
In practice, infringement is most often easiest to establish when the product matches dependent claim embodiments on salt/form, dose form, and administration regimen, alongside a close match to the compound definition.
3) How do design-arounds usually avoid a composition and method patent?
Design-arounds commonly pursue changes in chemical structure scope, switch to a non-covered salt/form, modify formulation composition elements, or alter route and regimen so method claims do not read on intended use.
4) How does the patent landscape expand beyond the issued US patent?
It expands via related continuations/divisionals, salt/formulation/use families from the same assignee, and competing filings targeting practical product differentiation and claimable use variants.
5) What matters most for freedom-to-operate against US 5,362,475?
The decisive factors are whether the target product falls within (a) the compound structural limits, (b) required composition/formulation limits, and (c) the claimed therapeutic method elements for indication and dosing.
References
[1] United States Patent and Trademark Office (USPTO). US Patent 5,362,475.
