United States Patent 12,329,731 (US12329731): Scope of Claims and US Patent Landscape for Intranasal Potassium Bumetanide Edema Therapy

Executive summary: US 12,329,731 claims a stable intranasal aqueous formulation of potassium bumetanide with specified ranges for concentration, tonicity (mannitol), preservative (benzyl alcohol), viscosity modifier (low viscosity sodium carboxymethyl cellulose), and pH (5 to 9; preferred 6 to 8), plus edema treatment methods using 25–250 µL doses, including limits on total bumetanide exposure (≤ ~10 mg over 12 hours) and dosing frequency (1–4 times in a six hour period). The claim set is heavily composition-and-dose constrained, with the strongest enforceable “center of gravity” located in the numerical formulation windows (mannitol/bromon? not; specifically mannitol, benzyl alcohol, low viscosity CMC-Na) and the intranasal delivery schema for edema in populations such as congestive heart failure or renal insufficiency, including patients with impaired GI absorption or reduced intestinal motility.

What is the claim scope of US 12,329,731 for intranasal potassium bumetanide?

Quick answer (claim architecture): The patent has two main independent claim themes:

Composition claim (Claim 1): A stable intranasal aqueous formulation defined by (i) potassium bumetanide salt concentration, (ii) tonicity agent, (iii) preservative, and (iv) viscosity modifying agent (CMC-Na or salt), with pH 5 to 9.
Method claims (Claims 9–20): Intranasal dosing regimens (dose volume and frequency) to treat edema, with optional subject qualifiers and exposure limits.

Independent claim mapping

Claim 1 (composition, broad tonicity/preservative)
- Potassium bumetanide salt: ~5 to ~10 mg/mL
- Tonicity agent: unspecified in Claim 1 (then constrained in Claim 3)
- Preservative: unspecified in Claim 1 (then constrained in Claim 2)
- Viscosity modifying agent: sodium carboxymethyl cellulose (low viscosity implied later) or salt
- pH: 5 to 9
Claim 6 (composition, narrow numeric “recipe”)
- Bumetanide: 0.5 to 2% wt/wt
- Low viscosity sodium carboxymethyl cellulose: 0.1% wt/wt
- Benzyl alcohol: 0.5% wt/wt
- Potassium ion: 0.078 to 0.31% wt/wt
- Mannitol: 2 to 4% wt/wt
- pH: 6 to 8
Claim 9 (method, dose volume window using Claim 1 composition)
- Intranasal dose volume: 25 to 250 µL
Claim 15 (method, dose volume window using Claim 6 composition)
- Same volume window but anchored to Claim 6 formulation

How do Claims 1 and 6 differ on enforceable boundaries?

Claim 1 is more flexible on tonicity and preservative identities (only later claims specify mannitol and benzyl alcohol). Enforceability typically hinges on proving the accused product contains:
- an intranasal stable composition with potassium bumetanide salt in ~5–10 mg/mL
- includes a preservative and tonicity agent
- includes CMC-Na (or salt) as the viscosity modifier
- and has pH 5–9
Claim 6 is narrower and easier to “read-across” in infringement analysis because it specifies exact ingredient identities and numeric ranges for:
- mannitol 2–4%
- benzyl alcohol 0.5%
- low viscosity CMC-Na 0.1%
- bumetanide 0.5–2%
- potassium ion 0.078–0.31%
- pH 6–8

What do the dependent claims add to the scope?

Key dependent constraints:

Claim 2: preservative is benzyl alcohol
Claim 3: tonicity agent is mannitol
Claim 4: bumetanide salt in aqueous solution is 6 ± 1 mg/mL
Claim 5: pH 6 to 8 (subrange of Claim 1)
Claims 7–8: specific embodiments of Claim 6:
- Claim 7: ~0.5% bumetanide (wt/wt)
- Claim 8: ~4% mannitol (wt/wt)
Method dependent constraints:
- Claim 10/16: 100 µL dose
- Claim 11/17: subject has congestive heart failure or renal insufficiency
- Claim 12/18: dosing 1–4 times over a six hour period
- Claim 13/19: total bumetanide exposure ≤ ~10 mg over 12 hours
- Claim 14/20: patient has impaired GI absorption of oral diuretic or reduced intestinal motility prior to dosing

Which formulation elements in US 12,329,731 are “must-match” for infringement risk?

1) Potassium bumetanide concentration and pH windows

Claim 1: 5–10 mg/mL potassium bumetanide salt; pH 5–9
Claim 6: 0.5–2% wt/wt bumetanide and pH 6–8

From a claim-coverage standpoint, the formulation is not generic “intranasal diuretic.” It is an intranasal aqueous stability-optimized composition with:

specific bumetanide salt form (potassium bumetanide salt)
specific pH corridor
specified excipient functional roles (tonicity, preservative, viscosity modifier)

2) Preservative: benzyl alcohol

Explicitly claimed in Claim 2 and Claim 6 recipe as 0.5% wt/wt benzyl alcohol.

3) Viscosity modifier: low viscosity sodium carboxymethyl cellulose

Claim 1: sodium carboxymethyl cellulose (or salt)
Claim 6: low viscosity CMC-Na at 0.1% wt/wt

4) Tonicity agent: mannitol

Claim 3: tonicity agent is mannitol
Claim 6: mannitol 2–4% wt/wt
Claim 8: example embodiment includes ~4% mannitol

5) Potassium ion specification (Claim 6)

Claim 6 also specifies potassium ion content 0.078–0.31% wt/wt. This can be a technical hook in infringement analysis because it ties formulation identity to the salt form and concentration. It can be used to distinguish “potassium-free” or “equivalent cation” approaches.

How broad are the intranasal dose method claims (Claims 9–20)?

Dose volume window

Claim 9 and 15: 25–250 µL intranasal dose volume.

Preferred dosing embodiment

Claim 10 and 16: 100 µL.

Frequency limitation

Claim 12 and 18: dosing not more than 1–4 times over a six hour period.

Total exposure cap

Claim 13 and 19: total bumetanide salt not more than ~10 mg over 12 hours.

Patient subgroup limitations

Claim 11/17: congestive heart failure or renal insufficiency
Claim 14/20: impaired GI absorption of oral diuretic therapy or reduced intestinal motility prior to dosing

Enforcement implication: The method claims are not purely “treat edema with intranasal bumetanide.” They add:

a specific administration volume window
dosing frequency constraints
a total exposure ceiling
and optional “real-world” patient qualifiers that can narrow proving the claimed method.

What formulations are protected: aqueous intranasal potassium bumetanide with mannitol/benzyl alcohol/CMC-Na?

Protected formulation “core” (Claim 6 recipe):

Ingredient / parameter	Claimed range / identity
Active	Bumetanide 0.5 to 2% (wt/wt)
Salt chemistry hook	Potassium ion 0.078 to 0.31% (wt/wt)
Viscosity modifier	Low viscosity sodium carboxymethyl cellulose 0.1% (wt/wt)
Tonicity	Mannitol 2 to 4% (wt/wt)
Preservative	Benzyl alcohol 0.5% (wt/wt)
pH	6 to 8
Dosage form type	Aqueous solution for intranasal administration

Protected formulation “broader” envelope (Claim 1):

Ingredient / parameter	Claimed range / identity
Active	Potassium bumetanide salt 5–10 mg/mL
Viscosity modifier	Sodium carboxymethyl cellulose (or salt)
pH	5–9
Tonicity agent	any tonicity agent in Claim 1
Preservative	any preservative in Claim 1

Practical takeaway: A company seeking to design around should treat Claim 6 as the most direct “on-ramp” for infringement because it is specific on excipient identity and numeric ranges. Claim 1 provides broader coverage but is more ambiguous because it leaves tonicity and preservative identity open unless dependent claims are asserted.

How does US 12,329,731 compare with typical intranasal formulation patent strategies?

Common strategy in intranasal products: patents often claim stability through pH/osmolality/viscosity, plus preservatives and tonicity agents. US 12,329,731 matches that approach but with unusually strong numerical specificity (mannitol 2–4%, benzyl alcohol 0.5%, CMC-Na 0.1%, pH 6–8, potassium ion 0.078–0.31% in Claim 6) and dose-exposure method constraints (25–250 µL, 1–4 doses in 6 hours, ≤10 mg in 12 hours).

Net effect: infringement disputes would likely pivot on:

whether an accused formulation has the same ingredient identities
whether it sits inside or outside the numeric ranges
whether measured pH and potassium ion content match the claimed thresholds
whether the administration scheme matches the claimed dosing volume and exposure cap

When does US 12,329,731 lose exclusivity in the US?

No usable answer can be produced from the information provided. A loss-of-exclusivity date requires the patent’s filing date, grant date, and any PTA/market exclusivity/extension events (and related Orange Book/NDA/ANDA/BLA linkages). The supplied prompt provides claims only and does not include these inputs.

What Orange Book status exists for intranasal potassium bumetanide products?

No usable answer can be produced from the information provided. Orange Book status depends on identifying the specific FDA application (NDA/ANDA) covering the intranasal potassium bumetanide product, plus its listed patents (including whether US 12,329,731 is listed as an active formulation/method-of-use patent) and associated expiration dates.

Which generic or biosimilar entry risks exist for intranasal bumetanide edema therapy?

No usable answer can be produced from the information provided. Generic entry risk requires:

the current marketed product(s) and application numbers
whether any ANDA has been filed or received Paragraph IV certification
whether there is any settlement
whether the claimed formulation and method-of-use patents are listed in the Orange Book for that NDA None of this is supplied.

Patent strength assessment for US 12,329,731 based on claim draftsmanship

1) Narrowness improves objective infringement clarity

Claim 6 is tight: it recites multiple ingredient identities with specific weight percentages and a pH band. That reduces the “obvious design-around” space compared with claims that only recite functional properties.

2) Multiple redundant hooks

The patent has multiple independent “anchors” likely to be litigated:

specific active salt form (potassium bumetanide)
potassium ion range (Claim 6)
mannitol tonicity band (Claim 6)
benzyl alcohol concentration (Claim 2 and Claim 6)
low viscosity CMC-Na at 0.1% (Claim 6)
pH corridor (Claim 1: 5–9; Claim 6: 6–8)
dosing volume and exposure constraints (Claims 9–13 and 15–19)

3) Method claims depend on actual use patterns

Even if an accused product makes and sells a formulation that fits Claims 1 or 6, method-of-use infringement turns on whether the dosing regimen used by the healthcare system matches:

dose volume
frequency cap over six hours
maximum total bumetanide exposure over twelve hours
patient condition descriptors (if needed to prove specific dependent claims)

How to use the claim set to map design-around options (formulation and dosing)?

Formulation design-around levers (based strictly on the claim language):

Alter pH outside the claimed bands:
- outside 5–9 for Claim 1, or
- outside 6–8 for Claim 6
Change or remove the specified excipient identities/levels:
- tonicity agent away from mannitol 2–4%
- preservative away from benzyl alcohol 0.5%
- viscosity modifier away from low viscosity CMC-Na 0.1%
Adjust potassium ion content outside 0.078–0.31% (Claim 6)

Method design-around levers:

Use dose volumes outside 25–250 µL
Adjust dosing frequency beyond 1–4 times over six hours
Exceed the “do not receive more than ~10 mg over 12 hours” cap
Treat edema in a way that does not match the claimed patient-condition qualifiers if those are required for the asserted dependent method claims

Claims-by-claim infringement checklist (high signal)

Use this to evaluate whether an accused product or development candidate falls into the patent’s literal coverage:

Intranasal aqueous composition
Contains potassium bumetanide salt:
- 5–10 mg/mL for Claim 1
- equivalent bumetanide wt/wt within 0.5–2% for Claim 6
Includes sodium carboxymethyl cellulose (or salt):
- any CMC-Na for Claim 1
- low viscosity CMC-Na 0.1% for Claim 6
Has pH 5–9 (Claim 1) or pH 6–8 (Claim 6)
Includes preservative:
- benzyl alcohol for Claim 2 or Claim 6
Includes tonicity agent:
- mannitol for Claim 3 or Claim 6
(If evaluating Claim 6) meets mannitol 2–4%, benzyl alcohol 0.5%, potassium ion 0.078–0.31%
(If evaluating method claims) intranasal administration volume and regimen:
- 25–250 µL
- dosing pattern of 1–4 times over 6 hours
- total bumetanide salt ≤ ~10 mg in 12 hours

Key Takeaways

US 12,329,731 centers on an intranasal aqueous potassium bumetanide formulation with tightly defined pH, mannitol tonicity, benzyl alcohol preservative, and low viscosity sodium carboxymethyl cellulose viscosity modifier.
The most enforceable “target” claim is Claim 6, which specifies ingredient identities and weight percentages, plus potassium ion content and pH 6–8.
The method-of-use claims add a practical dosing framework: 25–250 µL, with optional (dependent) caps on dosing frequency and total exposure over time.
The claim set is structured for litigation where infringement turns on analytical lab measurements (pH, viscosity agent identity/grade, preservative concentration, tonicity percent) and medication administration records (dose volume, dosing frequency, total exposure).

FAQs

What happens if a product matches bumetanide and pH but uses a different tonicity agent than mannitol?
Do the method claims require a specific patient diagnosis to be infringed, or can they apply broadly to edema treatment?
How do the potassium ion limits in Claim 6 affect formulation comparability for equivalents of potassium bumetanide?
If a product uses benzyl alcohol but at a concentration different from 0.5% wt/wt, which claims remain most vulnerable?
What dosing evidence typically matters most for infringement of intranasal dosing-volume and total-exposure limitations?

References (APA)

Provided claims text for US 12,329,731 (no external sources cited in the supplied prompt).

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Corstasis Therap	ENBUMYST	bumetanide	SPRAY;NASAL	219500-001	Sep 12, 2025		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y			INTRANASAL BUMETANIDE FOR THE TREATMENT OF EDEMA	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2020397176	⤷ Start Trial
Brazil	112022010879	⤷ Start Trial
Canada	3160278	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 12,329,731

Which drugs does patent 12,329,731 protect, and when does it expire?

Summary for Patent: 12,329,731