US Patent 8,735,452: Scope, Claims, and Patent-Landscape Significance
United States Patent 8,735,452 claims methods for treating pain in critically ill, non-inflamed patients using intravenous ibuprofen at defined dose ranges and exposure targets, with a central efficacy-safety constraint: no statistically significant increase in mean arterial pressure (MAP) during the dosing interval. The claims are drafted as dose-and-exposure anchored method claims with critically ill selection criteria tied to ICU status and organ-support interventions, and they repeatedly restrict treatment to patients not suffering from inflammation.
What is the claimed invention scope?
Core therapeutic method
The patent claims a method of treating pain by administering intravenous ibuprofen in selected dosing regimens and ensuring:
- Pain treatment is achieved (expressed via PK exposure bands, including Cmax and AUC),
- Patients are critically ill,
- Patients are not suffering from inflammation,
- The regimen produces no statistically significant increase in MAP during the dosage interval (relative to a baseline measured pre-dose).
This forms a three-part scope structure:
- Patient phenotype: critically ill + “not suffering from inflammation”
- Administration: intravenous ibuprofen, with specific doses/regimens
- Safety endpoint: MAP does not rise significantly
PK exposure targets used to define the method
The patent uses pharmacokinetic windows as claim-defining limitations. Representative exposure metrics include:
- Claim 1: mean Cmax ~20.8 to ~60 µg/mL with dosing 400 mg to 800 mg every 4 to 6 hours
- Claim 2: mean AUC ~36.8 to ~117.5 µg·h/mL
- Claims 4-7: dose-to-exposure relationships with percentage ranges (80% to 125% of specific target values), including:
- 400 mg: Cmax around 25.7 µg/mL (± via 80% to 125% band)
- 400 mg: AUC0-4 around 45.9 µg·h/mL (± via 80% to 125% band)
- 800 mg: Cmax around 60 µg/mL
- 800 mg: AUC0-t around 94 µg·h/mL (80% to 125% band)
- Claim 13: enumerated doses (100/200/400/800 mg) tied to specific mean Cmax values (with stated SD/variability in the claim language)
What are the independent and dependent claim layers?
Independent-like coverage inside claim set
While none of the claims you provided is labeled “independent” in the excerpt format, the claim structure shows broadest method coverage in claims such as 3 and 16, with increasingly specific dose/exposure and population selections in claims 1, 2, 13, and dependent claims.
Claim 3 (broad method with selection criteria)
Method of claim 3 treats pain by giving IV ibuprofen to critically ill, non-inflamed patients and requiring no statistically significant MAP increase, with critical-care selection defined by one or more of:
- Large volumes of blood products
- Dialysis
- Multiple antibiotics
- Pulmonary artery catheter or arterial pressure catheter inserted
- Combinations of the foregoing
This claim is broad in that it:
- Does not fix a single ibuprofen dose in the claim itself (it says “an amount effective,” then later narrows in dependent claims)
- Uses a negative safety endpoint (MAP unchanged statistically)
Claim 16 (broadest concept)
Claim 16 defines a method:
- Critically ill, increased risk of cardiovascular events
- Not suffering from inflammation
- IV ibuprofen dose effective to treat pain
- Provides no statistically significant MAP increase
Claim 16 does not specify PK bands in the excerpt, making it closer to a conceptual method covering any effective dose that meets the MAP constraint.
Claim 1 and Claim 2 (more specific exposure-defined regimen)
- Claim 1 anchors the method to:
- Dosing: 400 mg to 800 mg every 4 to 6 hours
- Exposure: mean Cmax 20.8 to 60 µg/mL
- Population: selected from critically ill, non-inflamed patients with MAP stability during the interval.
- Claim 2 ties to:
- Dosing the same way (400-800 mg every 4-6 hours)
- Exposure: mean AUC 36.8 to 117.5 µg·h/mL
Claim 13 (cardiovascular-risk critical patients with enumerated doses)
Claim 13 adds:
- Critically ill patients with increased risk of cardiovascular events
- Not suffering from inflammation
- One of four dose options (100/200/400/800 mg), each with a defined mean Cmax target
- MAP does not increase statistically
This claim is a structured dosing-choice claim: infringement analysis will hinge on whether the accused regimen yields the claimed Cmax targets and satisfies the MAP endpoint.
How does the patent define “critically ill” and “not suffering from inflammation”?
Critically ill selection (two layers)
The excerpt shows two sets of inclusion mechanisms:
-
General critically ill / ICU-type supports
- Claim 1 includes critically ill patients and references “patients selected from the group consisting of patients having a mean arterial pressure prior to intravenous administration…” (as written, this portion functions as a MAP-criterion rather than an ICU list).
- Claim 14 expands treatment settings: vasopressor support, mechanical ventilation, ICU care, large volumes of blood products, dialysis, multiple antibiotics, presence of pulmonary artery catheter or arterial pressure catheter, and combinations.
-
Explicit operational conditions
- Claim 3 enumerates: large volumes of blood products, dialysis, multiple antibiotics, catheterization.
- Claim 14 and 15 replicate broader “treatment selected from the group” for critically ill conditions.
This drafting approach suggests the patent expects use cases in ICU settings where hemodynamics are fragile and where ibuprofen could be perceived as risky.
“Not suffering from inflammation”
The claims repeatedly include the condition that patients:
- are not suffering from inflammation
The excerpt does not define “inflammation” operationally (e.g., biomarker thresholds). As a claim construction matter, the phrase operates as a patient selection limitation.
In practical terms, the scope depends on:
- Trial/clinical screening and documentation protocols
- Whether the accused regimen treats patients who could be categorized as “inflammation” based on clinical judgment or biomarker testing.
What are the dosing and administration constraints?
Dose range in the claim set
Key dose range statements include:
- 100 to 1600 mg (Claim 8)
- Enumerated dose options (Claim 9):
- 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 800, 1000, 1200, 1400, 1600, 2400, 3200 mg
- A narrower enumerated set (Claim 10): 100, 200, 400, 800 mg
- Specific dosing regimen for claims 1-2: 400 mg to 800 mg every 4 to 6 hours (Claim 1 and Claim 2)
Dosing interval
- Claim 11 adds interval selection:
- about every 4 hours
- about every 6 hours
- greater than every 6 hours
Pharmaceutical form limitation
- Claim 12: aqueous solution of arginine and ibuprofen
This matters for formulation competition: a product delivered in a different solvent system might avoid claim 12 specifically, but may still fall under other claims unless they also require arginine.
Exposure-based infringement triggers (Cmax and AUC windows)
Representative exposure constraints
The following table consolidates the excerpt’s exposure metrics by claim:
| Claim |
Dose constraint |
PK metric constraint in claim |
Directionality |
| 1 |
400–800 mg every 4–6 hours |
Mean Cmax 20.8–60 µg/mL |
In-range |
| 2 |
400–800 mg every 4–6 hours |
Mean AUC 36.8–117.5 µg·h/mL |
In-range |
| 4 |
400 mg |
Mean Cmax within 80%–125% of 25.7 µg/mL |
Tight band around target |
| 5 |
400 mg |
Mean AUC0-4 within 80%–125% of 45.9 µg·h/mL |
Tight band around target |
| 6 |
800 mg |
Mean Cmax about 80% of 60 µg/mL |
Lower/ceiling implied by wording |
| 7 |
800 mg |
Mean AUC0-t within 80%–125% of 94 µg·h/mL |
Tight band around target |
| 13 |
100/200/400/800 mg (choose one) |
Mean Cmax fixed per dose (with SD values stated) |
Dose-exposure matching |
| 3 / 16 |
“effective dose” (no fixed dose in excerpt) |
MAP statistically unchanged |
Safety endpoint drives |
Why the PK language drives claim scope
This is a method claim set in which:
- Dose alone is not always enough.
- Hemodynamic outcome (MAP stability) is a required safety limitation.
- PK exposure may be necessary where specified (claims 1-2 and 4-7 and 13).
Practically, scope segmentation looks like:
- Claims with PK limits create quantitative triggers.
- Claims without PK limits but with MAP limits create endpoint triggers (Claim 3 and Claim 16).
Cardiovascular-risk expansion: separate pathway in the claim set
Two claims add “increased risk of cardiovascular events” language:
These claims also retain:
- “not suffering from inflammation”
- MAP statistically unchanged
- Critically ill requirement
This creates a second population subclass: not just “critically ill,” but critically ill with specific cardiovascular risk. That makes the patent more defensible against arguments that the invention is only for general ICU pain.
Formulation scope: arginine-ibuprofen aqueous solution
The patent explicitly claims (Claim 12) the pharmaceutical composition as:
- an aqueous solution of arginine and ibuprofen
If a competitor uses an IV ibuprofen formulation in a different salt/vehicle, Claim 12 might not read on the product, but:
- other method claims may still apply if they do not require the arginine formulation.
So the formulation limitation is a narrow dependent claim hook, not necessarily the invention boundary.
US patent landscape analysis for 8,735,452 (what it blocks and where it leaves room)
1) What activity is most directly blocked
The claims most directly target:
- IV ibuprofen dosing in ICU/critically ill, non-inflamed populations
- With monitoring showing MAP does not increase statistically
- In dosing regimens that match specified dose/exposure windows where those claims are asserted
Infringement risk concentrates where companies run or plan:
- ICU pain programs using IV ibuprofen
- trials in cardiovascular-risk critical populations
- hemodynamically unstable patients where MAP endpoints are monitored
2) Where design-around exists within claim language (practical levers)
Because the claims are method claims, the most obvious design-around levers are:
- Patient selection: avoid treating patients who satisfy “not suffering from inflammation”
- Safety outcome: alter regimen so MAP increases statistically (in the relevant analysis sense) and documentation would not support “no statistically significant increase”
- Exposure mismatch: for claims with Cmax/AUC limits, a regimen that yields mean exposures outside the claimed windows may avoid those specific dependent claims
- Formulation: avoid arginine aqueous solutions to escape Claim 12
Those levers operate as claim-avoidance paths, though they may conflict with medical objectives.
3) Likely litigation posture and claim construction pressure points
The claim set contains three hotspots that typically drive dispute:
- “Not suffering from inflammation”
- Depends on clinical and biomarker screening standards
- “Mean arterial pressure does not increase during the dosage interval”
- Requires clarity on:
- baseline timing
- interval boundaries
- statistical definition used in the claim context
- PK band compliance
- Many claims depend on mean Cmax/AUC
- A regimen that changes sampling times or yields different exposure means could affect claim read
4) Competitive implications for IV ibuprofen in ICU pain
This patent makes “IV ibuprofen for ICU pain with hemodynamic stability” a guarded space. Competitors seeking market entry for critically ill pain will need:
- clinical protocols aligned to the claims’ endpoints and inclusion criteria, or
- explicit evidence that their patients do not meet the “non-inflammation” requirement, or
- proof that their mean exposures and MAP results do not satisfy the claim metrics.
Key Takeaways
- 8,735,452 is a method patent for IV ibuprofen pain treatment in critically ill, non-inflamed patients.
- The claims are anchored by a required safety endpoint: no statistically significant increase in mean arterial pressure.
- Several claims additionally require PK exposure bands (Cmax and AUC) tied to specific dose levels and dosing intervals.
- The patent adds a cardiovascular-risk subclass for critical patients (claims 13 and 16).
- A formulation-dependent hook exists: aqueous arginine-ibuprofen (Claim 12).
FAQs
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What endpoint defines safety in US 8,735,452 claims?
The claims require no statistically significant increase in mean arterial pressure (MAP) during the dosing interval relative to a baseline measured prior to IV ibuprofen.
-
Which claims are most dose-and-PK restrictive?
Claims 1, 2, 4-7, and 13 because they bind the method to mean Cmax and/or AUC targets, not only to MAP stability.
-
Does the patent require an arginine formulation?
Only Claim 12 explicitly requires an aqueous solution of arginine and ibuprofen; other method claims in the excerpt do not.
-
How are critically ill patients defined?
The excerpt shows inclusion by ICU-type conditions and interventions such as vasopressor support, mechanical ventilation, ICU treatment, large volumes of blood products, dialysis, multiple antibiotics, and catheter insertion, with combinations allowed.
-
Is “inflammation” operationally defined in the claims you provided?
The excerpt states the condition “patients are not suffering from inflammation” but does not define a measurable criterion.
References
- US Patent 8,735,452.
