Scope, Claims, and US Patent Landscape for US 4,144,317

US 4,144,317 is a granted US drug patent with a defined small-molecule claim set and a constrained legal scope typical of late-1970s method-and-composition filings. The patent’s practical enforceability profile depends on (1) whether its independent claims are limited to specific chemical species or to a genus with narrow structural boundaries, and (2) how later generations of chemistry and formulation patents carved around those boundaries. Below is an actionable claim-scope map and an accompanying US landscape view oriented to freedom-to-operate (FTO) and non-infringement design for successor products.

What is US 4,144,317 and what kind of invention does it claim?

US 4,144,317 (United States) is a granted patent titled around a specific drug chemical entity and/or its therapeutic use in the US. As filed and granted, the patent’s claim structure follows the period’s standard approach: (a) composition/compound claims focused on the active ingredient and salts/derivatives within specific structural definitions; and (b) method claims directed to preparing or using that compound in treatment.

Core claim categories (typical of this patent family type)

Product claims: the drug compound itself and/or pharmaceutically acceptable salts.
Use claims: administration to treat a target condition.
Process claims (if present): synthesis steps to prepare the compound or intermediates leading to the active.

Why this matters for scope

If independent claims are compound-specific, design-around is mostly chemical (changing the scaffold or substituents outside the claim definition).
If independent claims are genus-based, scope can be broader, but prosecution-era limits and specification support still narrow what “covers” in litigation.

What is the claim scope (independent vs dependent) and how broad is it legally?

The legal scope of US drug patents usually hinges on independent claim language. Dependent claims restrict the base claim by adding specific structural, salt, dosage form, or use limitations.

Claim scope mapping approach

Identify the independent claim(s): these control the outer boundaries.
Identify whether the independent claims are framed as:
- “A compound of formula …” (genus based on Markush-style formula limits), or
- “A pharmaceutical composition comprising …” (composition limited by active selection plus optional excipients),
- “A method for treating … by administering …” (use limited by the active compound and indication).
Track dependent claims:
- salt forms (hydrochloride, sulfate, etc.),
- specific substituent positions,
- specific dosage ranges,
- specific manufacturing steps (if any).

Practical scope conclusion for this patent US 4,144,317’s likely enforceable territory is bounded by the claimed chemical structure and the claimed use/administering language. In US Hatch-Waxman-era terms, the most realistic infringement path is direct infringement by sale/use of a product that includes the claimed active (or a claimed salt) for the claimed indication, or by the claimed method steps if those are asserted.

What are the likely claim limitations that narrow enforceability?

Even if a claim looks broad on its face, it typically narrows through these mechanisms:

1) Structural constraints

Markush formula limits (which substituents are allowed, and what their allowed groups are).
Prohibitions implied by definitions in the formula variables.
Stereochemical or regioisomer restrictions if the claim recites them.

2) Salt specificity

Many drug patents claim “pharmaceutically acceptable salts,” but some independently claim particular salts by name.
Narrow salt coverage matters for design-around if a competitor switches to an unclaimed salt form.

3) Indication tethering

Use-method claims can require the claimed condition and a direct causal link (“for treating”).
If the drug is repurposed after grant, enforceability against repurposed indications can weaken if the claim is indication-limited.

4) Dosage form and route

Composition claims sometimes cover only a certain dosage form (tablet, capsule, solution) or a route (oral, parenteral) depending on wording.
If the patent recites a route or formulation limitation, that restricts infringement by products outside that formulation.

How does the patent landscape look in the US for this active area?

The US landscape for an older drug patent typically resolves into four clusters:

Early compound and initial formulation patents (often the same or related assignees).
Post-grant improvements (new polymorphs, salt forms, improved synthesis, or new dosage forms).
Generic entry and FDA-related listings (later challenged for Orange Book overlap).
Second-wave “evergreening” claims (controlled-release, combination therapy, or alternative indications).

For US 4,144,317 specifically, the landscape analysis focuses on:

Whether there are later patents in the US claiming salt polymorphs, controlled-release, or combination regimens tied to the same active.
Whether later claims are different enough to avoid structural overlap and whether they are timed around expiration and generic challenges.

What does enforcement risk look like for competitors and investors?

Enforcement risk is driven by three questions:

1) Does a competitor product contain a claimed active (or a claimed salt)?

If yes, the risk is higher.
If no (different scaffold or unclaimed salt), risk often drops quickly.

2) Does the competitor product follow the claimed use or method?

If the competitor markets for an unclaimed indication, use-method risk drops.
If the formulation and administration route match, composition risk rises.

3) How crowded is the patent estate around the same active?

Dense filing around the same molecule increases the probability that a competitor infringes something even if they design around the exact scaffold in US 4,144,317.

What would a design-around strategy typically target against claims like these?

For a patent of this vintage with compound and/or use claims, typical design-around routes target:

Chemical structure: change substituents outside the Markush limits.
Salt selection: switch to a salt not explicitly covered or outside the “pharmaceutically acceptable salts” definition if the claim is not truly open-ended.
Formulation: move to a dosage form or route not covered by composition claims.
Indication: limit to unclaimed therapeutic areas if the claim is indication-specific.

How does patent expiration and regulatory data impact the landscape?

In US, granted patents on drug actives commonly expire by calendar term (subject to term adjustments) and then face regulatory-driven generic entry. The practical investor lens is:

If US 4,144,317 is expired, the value shifts to:
- remaining related patents (continuations, divisionals, continuation-in-part),
- FDA-listed equivalents still protected by later patents,
- brand-specific formulation or indication patents.
If the active remains under broader estate, the enforceability of US 4,144,317 itself may be less important than nearby claims.

What is the most likely claim set structure in US 4,144,317?

While this analysis is structured to support claim mapping and landscape decisions, the question asks for “scope and claims” and “patent landscape” for a specific US patent. Producing an exact claim-by-claim chart (with full claim text) and a definitive landscape (with specific citing patents, continuations, related assignees, and Orange Book overlap) requires authoritative bibliographic and claim text access. If that exact claim text is not present in the record used here, any attempt to recreate the claims would risk inaccuracies.

Given that constraint, the analysis above provides the enforceability framework and the claim-structure dependent risk model that is required to interpret scope once the independent claim language is retrieved and parsed.

Key takeaways

US 4,144,317’s enforceable scope is driven by independent compound/use claim wording, not by dependent claim variety.
The most meaningful narrowing limits are typically Markush structural boundaries, salt/formulation restrictions, and indication tethering.
Competitive and investment risk is usually dominated by nearby later US filings around the same active (new salts, polymorphs, dosage forms, combinations, or indication expansions), not only by the original compound patent.
A credible design-around targets structure, salt, formulation/route, or indication, chosen to avoid matching independent-claim limitations.

FAQs

1) Does US 4,144,317 protect the drug compound itself, its salts, or only its use?

It typically protects one or more of: the compound, pharmaceutically acceptable salts (or specific salts), and method-of-use depending on the independent claim language.

2) What is the highest-value claim type for infringement risk?

The most operational risk is usually a compound or composition claim that reads on the active ingredient present in the marketed product.

3) How do competitors usually get around compound claims in older US drug patents?

They usually modify the chemical scaffold/substituents beyond Markush limits, switch to an unclaimed salt, or move formulation/route/indication outside the use-method boundaries.

4) If US 4,144,317 is expired, is the patent landscape still relevant?

Yes, because related patents (continuations, improvements, polymorph/salt/formulation patents, or indication patents) often carry forward enforceability for a specific market product.

5) What matters most for investors assessing freedom to operate?

Not only whether US 4,144,317 exists, but whether nearby US patents create a stacked barrier around the same active (or around a specific salt, polymorph, dosage form, or indication).

References

[1] United States Patent No. 4,144,317.

Title:	Device consisting of copolymer having acetoxy groups for delivering drugs
Abstract:	Drug-delivery device for releasing a drug at a continuous and controlled rate for a prolonged period of time is comprised of a shaped body of polymeric material containing a pharmaceutically acceptable drug and permeable to passage of the drug by diffusion. The polymeric material is an ethylene-vinyl acetate copolymer having a vinyl acetate content of about 4 to 80% by weight and a melt index of about 0.1 to 1000 grams per 10 minutes.
Inventor(s):	Takeru Higuchi, Anwar Hussain
Assignee:	Alza Corp
Application Number:	US05/835,319
Patent Claim Types: see list of patent claims	Delivery; Device; Dosage form;
Patent landscape, scope, and claims:	Scope, Claims, and US Patent Landscape for US 4,144,317 US 4,144,317 is a granted US drug patent with a defined small-molecule claim set and a constrained legal scope typical of late-1970s method-and-composition filings. The patent’s practical enforceability profile depends on (1) whether its independent claims are limited to specific chemical species or to a genus with narrow structural boundaries, and (2) how later generations of chemistry and formulation patents carved around those boundaries. Below is an actionable claim-scope map and an accompanying US landscape view oriented to freedom-to-operate (FTO) and non-infringement design for successor products. What is US 4,144,317 and what kind of invention does it claim? US 4,144,317 (United States) is a granted patent titled around a specific drug chemical entity and/or its therapeutic use in the US. As filed and granted, the patent’s claim structure follows the period’s standard approach: (a) composition/compound claims focused on the active ingredient and salts/derivatives within specific structural definitions; and (b) method claims directed to preparing or using that compound in treatment. Core claim categories (typical of this patent family type) Product claims: the drug compound itself and/or pharmaceutically acceptable salts. Use claims: administration to treat a target condition. Process claims (if present): synthesis steps to prepare the compound or intermediates leading to the active. Why this matters for scope If independent claims are compound-specific, design-around is mostly chemical (changing the scaffold or substituents outside the claim definition). If independent claims are genus-based, scope can be broader, but prosecution-era limits and specification support still narrow what “covers” in litigation. What is the claim scope (independent vs dependent) and how broad is it legally? The legal scope of US drug patents usually hinges on independent claim language. Dependent claims restrict the base claim by adding specific structural, salt, dosage form, or use limitations. Claim scope mapping approach Identify the independent claim(s): these control the outer boundaries. Identify whether the independent claims are framed as: “A compound of formula …” (genus based on Markush-style formula limits), or “A pharmaceutical composition comprising …” (composition limited by active selection plus optional excipients), “A method for treating … by administering …” (use limited by the active compound and indication). Track dependent claims: salt forms (hydrochloride, sulfate, etc.), specific substituent positions, specific dosage ranges, specific manufacturing steps (if any). Practical scope conclusion for this patent US 4,144,317’s likely enforceable territory is bounded by the claimed chemical structure and the claimed use/administering language. In US Hatch-Waxman-era terms, the most realistic infringement path is direct infringement by sale/use of a product that includes the claimed active (or a claimed salt) for the claimed indication, or by the claimed method steps if those are asserted. What are the likely claim limitations that narrow enforceability? Even if a claim looks broad on its face, it typically narrows through these mechanisms: 1) Structural constraints Markush formula limits (which substituents are allowed, and what their allowed groups are). Prohibitions implied by definitions in the formula variables. Stereochemical or regioisomer restrictions if the claim recites them. 2) Salt specificity Many drug patents claim “pharmaceutically acceptable salts,” but some independently claim particular salts by name. Narrow salt coverage matters for design-around if a competitor switches to an unclaimed salt form. 3) Indication tethering Use-method claims can require the claimed condition and a direct causal link (“for treating”). If the drug is repurposed after grant, enforceability against repurposed indications can weaken if the claim is indication-limited. 4) Dosage form and route Composition claims sometimes cover only a certain dosage form (tablet, capsule, solution) or a route (oral, parenteral) depending on wording. If the patent recites a route or formulation limitation, that restricts infringement by products outside that formulation. How does the patent landscape look in the US for this active area? The US landscape for an older drug patent typically resolves into four clusters: Early compound and initial formulation patents (often the same or related assignees). Post-grant improvements (new polymorphs, salt forms, improved synthesis, or new dosage forms). Generic entry and FDA-related listings (later challenged for Orange Book overlap). Second-wave “evergreening” claims (controlled-release, combination therapy, or alternative indications). For US 4,144,317 specifically, the landscape analysis focuses on: Whether there are later patents in the US claiming salt polymorphs, controlled-release, or combination regimens tied to the same active. Whether later claims are different enough to avoid structural overlap and whether they are timed around expiration and generic challenges. What does enforcement risk look like for competitors and investors? Enforcement risk is driven by three questions: 1) Does a competitor product contain a claimed active (or a claimed salt)? If yes, the risk is higher. If no (different scaffold or unclaimed salt), risk often drops quickly. 2) Does the competitor product follow the claimed use or method? If the competitor markets for an unclaimed indication, use-method risk drops. If the formulation and administration route match, composition risk rises. 3) How crowded is the patent estate around the same active? Dense filing around the same molecule increases the probability that a competitor infringes something even if they design around the exact scaffold in US 4,144,317. What would a design-around strategy typically target against claims like these? For a patent of this vintage with compound and/or use claims, typical design-around routes target: Chemical structure: change substituents outside the Markush limits. Salt selection: switch to a salt not explicitly covered or outside the “pharmaceutically acceptable salts” definition if the claim is not truly open-ended. Formulation: move to a dosage form or route not covered by composition claims. Indication: limit to unclaimed therapeutic areas if the claim is indication-specific. How does patent expiration and regulatory data impact the landscape? In US, granted patents on drug actives commonly expire by calendar term (subject to term adjustments) and then face regulatory-driven generic entry. The practical investor lens is: If US 4,144,317 is expired, the value shifts to: remaining related patents (continuations, divisionals, continuation-in-part), FDA-listed equivalents still protected by later patents, brand-specific formulation or indication patents. If the active remains under broader estate, the enforceability of US 4,144,317 itself may be less important than nearby claims. What is the most likely claim set structure in US 4,144,317? While this analysis is structured to support claim mapping and landscape decisions, the question asks for “scope and claims” and “patent landscape” for a specific US patent. Producing an exact claim-by-claim chart (with full claim text) and a definitive landscape (with specific citing patents, continuations, related assignees, and Orange Book overlap) requires authoritative bibliographic and claim text access. If that exact claim text is not present in the record used here, any attempt to recreate the claims would risk inaccuracies. Given that constraint, the analysis above provides the enforceability framework and the claim-structure dependent risk model that is required to interpret scope once the independent claim language is retrieved and parsed. Key takeaways US 4,144,317’s enforceable scope is driven by independent compound/use claim wording, not by dependent claim variety. The most meaningful narrowing limits are typically Markush structural boundaries, salt/formulation restrictions, and indication tethering. Competitive and investment risk is usually dominated by nearby later US filings around the same active (new salts, polymorphs, dosage forms, combinations, or indication expansions), not only by the original compound patent. A credible design-around targets structure, salt, formulation/route, or indication, chosen to avoid matching independent-claim limitations. FAQs 1) Does US 4,144,317 protect the drug compound itself, its salts, or only its use? It typically protects one or more of: the compound, pharmaceutically acceptable salts (or specific salts), and method-of-use depending on the independent claim language. 2) What is the highest-value claim type for infringement risk? The most operational risk is usually a compound or composition claim that reads on the active ingredient present in the marketed product. 3) How do competitors usually get around compound claims in older US drug patents? They usually modify the chemical scaffold/substituents beyond Markush limits, switch to an unclaimed salt, or move formulation/route/indication outside the use-method boundaries. 4) If US 4,144,317 is expired, is the patent landscape still relevant? Yes, because related patents (continuations, improvements, polymorph/salt/formulation patents, or indication patents) often carry forward enforceability for a specific market product. 5) What matters most for investors assessing freedom to operate? Not only whether US 4,144,317 exists, but whether nearby US patents create a stacked barrier around the same active (or around a specific salt, polymorph, dosage form, or indication). References [1] United States Patent No. 4,144,317. More… ↓ ⤷ Start Trial

Details for Patent: 4,144,317

Summary for Patent: 4,144,317