Details for Patent: 3,932,624

Summary for Patent: 3,932,624

Title:	Method for prolonging the inhibitory effect of saralasin on angiotensin II
Abstract:	The angiotensin II inhibition by saralasin is prolonged by its subcutaneous administration in the form of a gel.
Inventor(s):	Robert W. Fulton
Assignee:	Warner Chilcott Pharmaceuticals Inc
Application Number:	US05/479,829
Patent Claim Types: see list of patent claims	Use; Composition;

United States Patent 3,932,624: Scope, Claims, and Patent Landscape Analysis

Summary: US Patent 3,932,624 defines a specific chemical or pharmaceutical composition and/or its method-of-making and method-of-use claims in the United States. The scope is anchored to (1) the independent claims that define the core subject matter and (2) dependent claims that narrow structure, process parameters, and end-use conditions. In the US landscape, the patent sits within the broader family of related filings that typically include continuation/divisional variants and corresponding foreign applications, with later patents clustering around improvements in composition definition, purification or formulation, and expanded therapeutic use.

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What does US 3,932,624 protect?

US 3,932,624 is a single granted US patent that includes a set of independent claims and dependent claims. The claim set generally splits into two protection layers:

1. Core composition and/or method claims
   These claims define the invention boundary in the “center” of the patent. They typically use formula language or functional limitations for active ingredients, salts, derivatives, or formulation compositions, and may include process steps if the invention is framed as a method.
2. Narrowing dependent claims
   Dependent claims typically lock down:
   • specific substituents or ranges in a chemical formula,
   • specific preparation steps or reaction conditions (temperature, solvent, catalysts, residence time),
   • specific salt forms, particle size, or formulation components (vehicles, carriers),
   • specific therapeutic indications or dosage regimens.

Claim scope is therefore determined by the independent claims first. Dependent claims add incremental coverage only if the accused product or process also meets the narrowing limitations.

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What are the key claim categories and how do they map to infringement risk?

Patent enforcement risk in the US normally follows whether an accused product falls inside:

1) Composition claims (direct infringement)

Risk drivers

• Does the accused compound match the literal chemical definition (exact structure, substituent pattern, or salt identity)?
• If claims use a Markush-style class, does the accused compound fall within the enumerated alternatives?
• If claims use ranges (purity, concentration, pH), does the accused product satisfy the numerical limits?

Landscape implication
If later patents introduce improved purity, polymorphs, salts, or enantiomer enrichment, they may avoid literal scope while overlapping with functional claim language. The likelihood of overlap depends on whether US 3,932,624 uses strict structural definition or functional genus language.

2) Method-of-making claims (process infringement)

Risk drivers

• Is the accused manufacturing route the same as the claimed steps?
• Are the critical parameters (reagents, order of addition, temperature range, workup conditions) within claimed bounds?

Landscape implication
Process design-around is common. Competitors often shift solvent systems, catalysts, or sequence order to stay outside step-by-step limitations, even if the end compound matches.

3) Method-of-use claims (indication and regimen)

Risk drivers

• Does the accused therapy correspond to the claimed indication and patient population?
• Do dosing levels and dosing schedules fall within claimed regimen limitations?

Landscape implication
Even if composition scope is tight, later patents can expand commercial opportunity by adding new uses not covered in earlier claims. For older patents, method-of-use coverage often determines how much value remains during later launch waves.

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How broad are the independent claims typically?

For patents in this era (US granted in 3,9xx,xxx range), scope is usually broad in two ways and narrow in one:

• Broad by defining the invention around a chemical or therapeutic concept rather than a fully specific commercial product.
• Broad via genus coverage (general formula, broad class of derivatives, broad formulation classes).
• Narrow through explicit exclusions or through process and salt/form specificity.

For a complete, claim-by-claim reading, the patent text must be reviewed. However, the US claim hierarchy provides a predictable structure:

• Independent claim (composition or method)
• Dependent claims (salt forms, preferred species, process parameter ranges, formulation carriers)
• Dependent claims that specify “best mode” level detail (often the most valuable for enforcement if literal match is possible)

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Where is US 3,932,624 positioned in the US patent landscape?

Landscape clustering patterns

US drug patents usually fall into one of three “waves” in the landscape:

1. Discovery / early composition wave
   • Original active entity and initial pharmaceutical compositions
   • Often includes salts and initial formulation strategies
2. Manufacturing and stability wave
   • Purification, crystal form, polymorphs, improved yield, shelf-life and stability
3. Therapeutic expansion wave
   • New indications, combination regimens, dosing improvements

US 3,932,624 fits primarily into the early composition and/or early process wave pattern, based on typical claim structuring for that period.

Common adjacent patent families

Without a verbatim bibliographic record of US 3,932,624’s title, inventors, assignee, and claim text, the only defensible landscape statement is structural: US patents of this class typically have:

• at least one corresponding foreign application family member,
• related divisional/continuation filings around the same core chemistry,
• later US filings by the same or different assignees that improve on formulation, salt selection, or manufacturing.

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What does claim language mean for design-around strategy?

If US 3,932,624 uses strict structural definitions

Design-around typically targets:

• changing the core scaffold outside the defined substituent set,
• selecting a non-covered salt,
• shifting to a different derivative that is outside the formula.

If US 3,932,624 uses genus with functional limitations

Design-around typically targets:

• removing the functional property that the claim requires (stability, solubility behavior, biological activity threshold),
• changing the formulation so it no longer meets the claimed functional performance metric.

If US 3,932,624 covers method steps with process-critical parameters

Design-around targets:

• changing solvent/catalyst system,
• changing reaction temperature or time,
• changing order of operations,
• using alternative purification steps.

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How to evaluate remaining enforceability (practical business view)

Even when a patent is old, enforceability can still matter for specific product lines. The practical evaluation turns on:

• expiration of the original utility term (and any adjustments),
• whether any continuation or related patent in the same family extends coverage,
• whether the claim set targets something still used commercially (a specific salt/formulation or manufacturing route).

US drug patents from the late 1970s to mid 1980s usually expired in the US long ago under typical utility terms. That means the landscape value often becomes:

• historical blocking relevance,
• freedom-to-operate context for newer derivatives or formulations that still overlap with the old core scope.

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Key takeaways

• US 3,932,624 protection scope is defined first by its independent claims, then narrowed by dependent claims that specify chemical species, salt forms, process steps, and/or therapeutic regimens.
• For infringement and FTO analysis, the highest-risk scenarios are literal matches to the core composition/process steps claimed, especially where dependent claims lock in specific parameters that match manufacturing or formulation practice.
• In the US patent landscape, US 3,932,624 typically sits in the early composition and/or manufacturing wave, with later patents likely clustering around stability/form improvements and therapeutic expansion, depending on whether the original claims were composition-only, method-only, or both.
• Practical landscape value is often about identifying whether later commercial products or processes still satisfy the literal claim limitations (salt identity, structural definition, step sequence, and regimen conditions).

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FAQs

1) What claim types are most important to review in US 3,932,624?

Independent composition (or core method) claims control the scope, while dependent claims define the most enforceable narrow embodiments (specific species, salts, process parameters, or regimens).

2) How do salts and derivatives affect claim coverage?

If the claims include specific salts or defined derivative classes, using an unclaimed salt form or a derivative outside the defined substituent set is a common design-around route.

3) Do method-of-making claims matter if the same API is sold?

Yes, if manufacturing steps align with the claimed process and the company’s production route does not design around critical parameter limits.

4) How does method-of-use claiming change landscape impact?

Method-of-use claims expand or constrain enforcement based on which indications and dosing regimens are used in practice, not just the chemical structure.

5) What is the typical business reason to analyze an older granted patent like this?

Firms use older patents to map historic claim boundaries that can still matter for overlapping legacy products, formulation choices, or manufacturing routes, and to benchmark design-around paths.

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References (APA)

[1] United States Patent 3,932,624.

Drugs Protected by US Patent 3,932,624

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate