Scope, Claims, and Patent Landscape for US Drug Patent 6,872,390

US Patent 6,872,390 is directed to a ready-to-use dental local anesthetic syringe compatible solution for reversing anesthesia that results from prior administration of an anesthetic agent plus an alpha adrenergic receptor agonist, using phentolamine mesylate at defined concentration and container/dose constraints.

The claims are narrow on (1) active ingredient form (phentolamine mesylate), (2) use condition (reversing anesthesia after an anesthetic plus alpha adrenergic agonist), (3) product presentation (fits in a “standard dental local anesthetic syringe” and optionally specifies a carpule), and (4) dose and volume windows.

What is the claim center of gravity?

Core independent claim (Claim 1)

Claim 1 defines the invention as:

Composition: solution comprising phentolamine mesylate
Concentration range: about 0.001 mg/mL to about 0.25 mg/mL
Functional use: “effective to reverse anesthesia in an animal caused by previous administration of an anesthetic agent and an alpha adrenergic receptor agonist”
Delivery constraint: “present in a container that fits into a standard dental local anesthetic syringe”

This places the “center of gravity” at the intersection of:

Reversal pharmacology: alpha-adrenergic antagonism by phentolamine to reverse anesthesia produced by an anesthetic plus an alpha agonist.
Dental cartridge compatibility: formulation in a container format used by dental local anesthesia delivery systems (syringe compatible; “carpule” in dependent claims).
Strict formulation window: very low mg/mL dosing.

Dependent claim concentration tightenings (Claims 2, 9, 10)

Claim 2: 0.05 to 0.1 mg/mL
Claim 9: 0.05 to 0.25 mg/mL
Claim 10: 0.25 mg/mL (endpoint)

The strongest claim pressure is therefore on mid-to-low single-digit concentration bands (particularly around 0.05–0.1 mg/mL and 0.25 mg/mL).

How do the dose and container limitations narrow scope?

Dose-defined embodiments (Claims 3, 4, 5, 6, 11, 12)

The claims layer dose caps and specific numerical dose embodiments on top of concentration:

Claim 3: container comprises a dose of phentolamine mesylate at or below 0.25 mg
Claim 4: dose at or below 0.1 mg
Claim 5: dose about 0.08 mg
Claim 6: dose about 0.032 mg
Claim 11: dose 0.0018 mg to 0.45 mg
Claim 12: dose 0.09 mg to 0.45 mg

Key point: Claims 3 and 4 impose upper caps (0.25 mg; 0.1 mg), while Claims 11 and 12 define broader ranges up to 0.45 mg. That means the patent covers both:

very low dose carpule options (including 0.032 mg and 0.08 mg), and
higher dose variants (up to 0.45 mg), depending on which dependent claim is asserted.

Volume-defined embodiment (Claim 8)

Claim 8: container volume between 1.6 and 1.8 mL

This ties dose to concentration through cartridge geometry:

If volume is ~1.6–1.8 mL, then the concentration range translates into dose ranges that align with the dose limitations seen in Claims 4–6 and 11–12.

Container form factor (Claim 7)

Claim 7: container is a CARPULE

“Carpule” is a strong structural limitation because it narrows the product configuration to dental anesthetic cartridges.

What does the functional language cover, and what does it exclude?

Functional language in Claim 1

The reversal is triggered by:

“anesthesia in an animal caused by previous administration of an anesthetic agent and an alpha adrenergic receptor agonist”

This ties the method of use to a specific anesthesia etiology:

Not just “anesthesia” in general,
but anesthesia created by a combination of an anesthetic agent and an alpha adrenergic receptor agonist.

That structure supports arguments that the claim is directed to reversal of alpha-agonist mediated effects within a dental local anesthesia context, where alpha agonists are used (e.g., to prolong duration).

Exclusions implied by Claim 1 construction

Even without explicit exclusions, the claim is structurally limited by:

requiring prior administration of both an anesthetic agent and an alpha adrenergic receptor agonist, and
requiring phentolamine mesylate in a syringe-compatible container.

As a practical design-around lens, a product that does not involve:

alpha adrenergic receptor agonist driven anesthesia, or
the specified delivery format, would have weaker infringement positioning for Claim 1.

Claim chart: what each claim adds (scope stacking)

Claim	Added limitation	Scope impact
1	Phentolamine mesylate, 0.001 to 0.25 mg/mL, reversal of anesthesia caused by prior anesthetic + alpha agonist, fits standard dental local anesthetic syringe	Establishes product concept and key boundaries
2	0.05 to 0.1 mg/mL	Tightens concentration; targets mid-range dosing
3	dose ≤ 0.25 mg	Adds dose cap on top of Claim 1
4	dose ≤ 0.1 mg	Further narrows dose
5	dose ~0.08 mg	Locks a specific dosage embodiment
6	dose ~0.032 mg	Locks a specific low dosage embodiment
7	container is CARPULE	Structural delivery limitation
8	container volume 1.6–1.8 mL	Adds physical cartridge volume constraint
9	concentration 0.05 to 0.25 mg/mL	Alternative concentration window (wider to 0.25)
10	concentration 0.25 mg/mL	Specific concentration endpoint
11	dose 0.0018 to 0.45 mg	Broad dose range dependent on container dose compliance
12	dose 0.09 to 0.45 mg	Mid-to-upper dose band dependent on container dose compliance

What is the practical infringement “surface area”?

Strongest infringement scenarios

Products most likely to map directly to claim elements would be those that satisfy all of:

phentolamine mesylate (not free base or other salt forms),
solution formulation (not solid, not topical outside syringe format),
concentration within 0.001–0.25 mg/mL, and
packaged in a standard dental local anesthetic syringe format, with carpule being a high-probability fit,
positioned for reversal in settings where anesthesia was caused by an anesthetic plus an alpha adrenergic receptor agonist.

“Edge” scenarios based on numbers

If a product lands at 0.25 mg/mL, it can target Claim 10.
If it lands at ~0.05–0.1 mg/mL, it fits Claim 2 and overlaps with Claim 9.
If it delivers per-cartridge doses near 0.032 mg or 0.08 mg, it can target Claims 6 and 5, respectively.
If cartridge volume is constrained to 1.6–1.8 mL, that supports Claim 8 and helps align concentration to dose.

What is the patent landscape around this concept?

This patent’s landscape position is best understood as a formulation-and-device constrained use patent: phentolamine mesylate in a dental syringe/carpule format with specific concentration/dose windows for reversing alpha-agonist associated anesthesia.

Landscape structure (how other rights typically cluster)

Within this technological space, patents usually cluster into three overlapping buckets:

Alpha-adrenergic antagonist reversal therapies
- rights covering using alpha antagonists (including phentolamine) to reverse anesthesia or vasoconstriction effects tied to alpha agonists.
Formulation and dosing for dental cartridges
- rights directed to concentrations, cartridge volume, and dose per carpule (to standardize administration through dental delivery equipment).
Delivery format and compatibility
- rights tying active agent solution to carpules or dental syringe systems.

US 6,872,390 is explicitly positioned to sit across all three buckets by combining:

active agent identity and salt form,
numerical concentration/dose windows, and
syringe/carpule format plus cartridge volume.

Business implication for FTO screens

When screening freedom-to-operate around dental reversal compositions:

treat this as a numeric claim barrier: your formulation, dose per cartridge, and cartridge volume matter as much as pharmacology,
treat delivery format as a gating factor: “fits into a standard dental local anesthetic syringe” and “CARPULE” create product-configuration hooks.

How should the claims be interpreted for scope strategy?

1) The patent is not a generic “phentolamine for reversal” claim

Claim 1 is a specific solution in a specific delivery container with bounded concentrations.

That means rights are strongest for products that are marketed and packaged as carpule solutions for reversal after anesthetic plus alpha agonist.

2) Numeric ranges create both overlap and carve-out pressure

Because claims are pegged to mg/mL and mg-per-cartridge, formulation work that changes:

concentration,
cartridge volume,
dose per carpule, can materially alter infringement posture under dependent claims.

3) Dose and volume linkage reduces “just change concentration” strategies

The presence of both:

container volume (1.6–1.8 mL),
and multiple dose limits (0.032 mg, 0.08 mg, ≤0.1 mg, and up to 0.45 mg) means product developers cannot rely on concentration shifts without also reconciling total dose and cartridge volume.

Key constraints embedded in the claim numbers

Parameter	Claim-bound range / value
Concentration (Claim 1)	about 0.001 to about 0.25 mg/mL
Concentration (Claim 2)	about 0.05 to about 0.1 mg/mL
Concentration (Claim 9)	about 0.05 to about 0.25 mg/mL
Concentration (Claim 10)	about 0.25 mg/mL
Container volume (Claim 8)	1.6 to 1.8 mL
Dose per container (Claim 3)	≤ 0.25 mg
Dose per container (Claim 4)	≤ 0.1 mg
Specific dose (Claim 5)	about 0.08 mg
Specific dose (Claim 6)	about 0.032 mg
Broad dose range (Claim 11)	0.0018 to 0.45 mg
Mid-upper dose range (Claim 12)	0.09 to 0.45 mg

Key Takeaways

US 6,872,390 is built around a phentolamine mesylate solution with defined mg/mL limits for reversing anesthesia caused by prior administration of an anesthetic plus an alpha adrenergic receptor agonist.
The patent scope is constrained by product presentation: the solution must be in a container that fits a standard dental local anesthetic syringe, with CARPULE and 1.6–1.8 mL volume expressly claimed in dependents.
The strongest claim value for enforcement lies in products that are carpule-formatted and land within the defined concentration and dose windows, including specific dose embodiments of 0.032 mg and 0.08 mg.
From an FTO standpoint, infringement posture is primarily a function of numeric formulation parameters (mg/mL and mg per cartridge) and container/delivery compatibility, not just the drug’s pharmacology.

FAQs

1) Does US 6,872,390 cover phentolamine in any dosage form?

No. The claims require a solution of phentolamine mesylate in a container compatible with a standard dental local anesthetic syringe, and dependently a CARPULE.

2) What is the broadest concentration claim range?

Claim 1 recites about 0.001 mg/mL to about 0.25 mg/mL.

3) Are there specific cartridge volume limits?

Yes. Claim 8 requires 1.6 to 1.8 mL.

4) Are there specific dose embodiments?

Yes. Claims 5 and 6 recite about 0.08 mg and about 0.032 mg.

5) Does the use require an alpha adrenergic receptor agonist?

Yes. Claim 1 ties reversal to anesthesia caused by previous administration of an anesthetic agent and an alpha adrenergic receptor agonist.

References

[1] US Patent 6,872,390 (claims as provided by user).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	352300	⤷ Start Trial
Australia	2001259848	⤷ Start Trial
Australia	2005211689	⤷ Start Trial
Australia	5984801	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,872,390

Summary for Patent: 6,872,390