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Patent landscape, scope, and claims: |
United States Patent 7,566,460 Scope and Claims: Hydroalcoholic Chlorhexidine Salt Compositions with Specialized Hydrophobe/Hydrophile Emulsifiers
USP 7,566,460 claims a topical, hydroalcoholic composition that combines (i) a chlorhexidine salt (with dependent fallbacks to diacetate and digluconate, especially chlorhexidine digluconate), (ii) a defined emulsifier “architecture” (long-chain hydrophobe at a minimum carbon count plus an EO/PO-linked or other hydrophilic segment via ether/ester), and (iii) optionally additional emollients and/or therapeutic agents. The claims also extend to method-of-use for skin moisture maintenance/improvement via topical application.
At a high level, the claim scope breaks into three layers:
- Base composition claim (chopper): hydroalcoholic solvent range + chlorhexidine salt + emulsifier amount threshold with defined hydrophobe/hydrophile groups.
- Tightened performance/format claims (funnel): narrower solvent ratios, specified melt temperature and stability, HLB window.
- Downstream use claims (bridge): moisturizing/moisture maintenance methods from applying the composition.
What is the claim scope of US 7,566,460 for chlorhexidine hydroalcoholic compositions?
Featured snippet answer: The patent claims topical compositions that contain a hydroalcoholic solvent (lower alcohol + water), a chlorhexidine salt (diacetate or digluconate, including chlorhexidine digluconate), and an emulsifier with a defined long hydrophobic group (≥24 carbons in claim 1) and a hydrophilic group that can include EO/PO-containing segments bonded through ether/ester bonds. Dependent claims further narrow to melt temperature, viscosity, and HLB/stability in claim 16.
Core independent claim (Claim 1): what is the “must-have” composition package?
Claim 1 recites the following required elements:
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Hydroalcoholic solvent
- Lower alcohol:water weight ratio about 60:40 to about 100:0
This spans from relatively water-heavy mixtures (about 60% alcohol / 40% water) to substantially anhydrous alcohol systems (approaching 100:0).
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Chlorhexidine salt
- Unspecified in claim 1 beyond being a “chlorhexidine salt.”
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Emulsifier at a minimum loading
- At least about 0.05% by weight, based on total composition weight.
- This is a threshold claim that turns on presence and concentration, not necessarily on any particular emulsifier brand.
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Emulsifier architecture
- The emulsifier “comprises”:
- (i) Hydrophobic group selected from:
- Alkyl group ≥24 carbon atoms
- Alkenyl group ≥24 carbon atoms
- Aralkyl or aralkenyl group ≥24 carbon atoms
- (ii) Hydrophilic group selected from a specified menu, including:
- EO/PO-containing group bonded through an ether or ester bond to the hydrophobic group; optionally terminated with C1–C36 alkyl ester, C2–C36 alkenyl ester, or C6–C36 alkaryl ester
- Alcohol group, polyhydric alcohol group
- Ester/ether group of a polyhydric alcohol or polyalkoxylated derivative
- Ester/ether group of sorbitan or polyalkoxylated derivative with 2–150 moles alkylene oxide per mole hydrophobic group
- Combinations
Interpretation of the claim architecture (scope consequence):
- The emulsifier must have at least one qualifying long-chain hydrophobe (≥24 C) and at least one qualifying hydrophile segment from the list.
- The claim does not require a specific emulsifier identity, only meeting the structural constraints.
Dependent constraints in Claim 1: performance and salt narrowing
- Claim 2: melt temperature > about 25°C
- Claim 3: viscosity ≥ about 25.5 cP at 23°C
- Claim 4: chlorhexidine salt is diacetate and/or digluconate
- Claim 5: chlorhexidine digluconate
- Claim 6: chlorhexidine digluconate 0.05% to 5.0%
- Claim 7: optionally includes at least one emollient distinct from emulsifier
- Claim 8: optionally includes at least one therapeutic agent
- Claims 9-10: emulsifier includes ≥2 hydrophobic groups and/or ≥2 emulsifiers
- Claims 11-13: emollient solubility behavior and total emollient 3–30 wt%
- Claims 14-15: emollient can be a polyether/polysiloxane copolymer surfactant, with a defined chemical structure and parameter ranges (x+y, R8, p, q, etc.).
Emollient sub-claim (Claim 14/15): what exact chemistry is captured?
Claim 15 gives a structural template for the polyether/polysiloxane copolymer surfactant:
- Backbone: (CH3)3–Si–O–[Si(CH3)R11–O]x [Si(CH3)R8–O]y –Si(CH3)3
- x+y = 5–400, preferably 15–200
- R8 defined as a polyether-substituted alkyl group:
- —R9—O(C2H4O)p(C3H6O)qR10
- R9 alkyl C1–C6
- R10 hydrogen or alky C1–C22
- R11 alkyl C1–C22 or phenyl
- p = 2–300, preferably 8–100
- q = 0–100
Scope consequence: the patent can read on formulas where the “emollient distinct from emulsifier” is a specific class of silicone-polyether surfactants/copolymers, not merely any emollient.
How does Claim 16 change the scope versus Claim 1 (melt temperature, solvent window, HLB, stability)?
Claim 16 is another independent composition claim that tightens performance and formulation parameters and relaxes some group carbon-number minimums relative to claim 1.
Claim 16: a narrower hydroalcoholic ratio plus defined emulsifier HLB and stability
Claim 16 recites:
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Hydroalcoholic solvent ratio
- lower alcohol:water about 60:40 to about 75:25
This is a narrower and more water-inclusive band than claim 1.
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Chlorhexidine salt + emulsifier system
- Same general concept: chlorhexidine salt and at least one emulsifier at ≥0.05 wt%.
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Emulsifier architecture carbon counts tightened differently
- Hydrophobic group minimums in claim 16:
- alkyl ≥16 carbons
- alkenyl ≥16 carbons
- aralkyl/aralkenyl ≥20 carbons
- Compared to claim 1, this reduces hydrophobe carbon minimums.
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Emulsifier hydrophile menu
- Same list categories (EO/PO bond-through ether/ester, alcohol/polyhydric alcohol, ester/ether groups, sorbitan/alkoxylated sorbitan with 2–150 moles alkylene oxide, etc.).
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HB L and performance
- Emulsifier system weight-average HLB about 4 to about 16
- Melt temperature > about 35°C
- Composition is stable
Scope consequence:
- Claim 16 is designed to capture a formulation that is not just structurally consistent, but also sits within a specific HLB window and meets higher melt temperature and stability requirements.
- A competitor can be structurally close but potentially evade if it falls outside the HLB or melt/stability constraints.
Dependent claims off Claim 16
- Claims 17-18-19-20: emollient distinct from emulsifier; salt selection diacetate/digluconate; chlorhexidine digluconate; concentration 0.05–5.0%.
- Claims 21-23: therapeutic agent; ≥2 hydrophobic groups; ≥2 emulsifiers.
- Claims 24-26: emollient solubility and total emollient 3–30 wt%.
- Claims 27-28: emollient includes polyether/polysiloxane copolymer surfactant with essentially the same structure template (claim 28 mirrors claim 15).
What formulations are implicitly covered: chlorhexidine diacetate vs digluconate, and solvent extremes?
Chlorhexidine salt coverage
- Claim 4/18: salt is selected from diacetate and digluconate salts
- Claim 5/19: specifically chlorhexidine digluconate
- Claim 6/20: digluconate concentration 0.05–5.0 wt%
Practical formulation boundary:
- If a product uses chlorhexidine acetate/alternative salts not encompassed by diacetate/digluconate, it may avoid dependent claim narrowing. Claim 1 and 16 still require “a chlorhexidine salt,” but the strongest dependent anchors are diacetate/digluconate.
Solvent system boundaries
- Claim 1 allows alcohol:water from 60:40 to 100:0 (water can be progressively removed).
- Claim 16 restricts to 60:40 to 75:25, keeping more water in the system.
Evasion vector (formulation design):
- A formulator can attempt to position outside one independent claim’s solvent band, while still potentially falling within the other. For litigation risk mapping, claim 1 is the broader solvent band; claim 16 is narrower but adds HLB/melt/stability limits.
How do the emulsifier structural requirements translate into “design-around” risk?
The hydrophobic group minimums act as the main structural gate
- Claim 1: hydrophobic group ≥24 carbons
- Claim 16: hydrophobic group ≥16 carbons (aralkyl/aralkenyl ≥20)
Key point for freedom-to-operate mapping: if an emulsifier candidate uses shorter hydrophobes (below these thresholds), it will likely fall outside the independent claim structures even if it has an EO/PO or sorbitan hydrophile.
Hydrophile selection is broad
The hydrophilic segment list includes both:
- EO/PO-containing group bonded through ether/ester to the hydrophobe, and
- non-EO alternatives like alcohol/polyhydric alcohol and sorbitan/polyalkoxylated sorbitan with 2–150 moles alkylene oxide.
This makes the emulsifier “menu” broad enough that many commercially known surfactants could match depending on chain lengths and bonding/termination.
HLB window makes Claim 16 more testable
Claim 16 adds:
- weight-average HLB 4 to 16
- melt temperature > 35°C
- stable
Even if a formula meets the emulsifier architecture, failing HLB or stability/melt criteria could defeat claim 16 while still potentially meeting claim 1 (which does not include HLB/stability language in the claim text you provided).
What method-of-use claims exist in US 7,566,460?
Claim 29 and 30: moisture maintenance methods
- Claim 29: method of maintaining/improving skin moisture content by applying the composition of claim 1.
- Claim 30: same method by applying the composition of claim 16.
Scope consequence: even if a competitor manufactures a composition that fits the composition claims, the method claims tie the alleged infringement to use/application for the moisturizing/moisture maintenance purpose.
How many distinct claim “targets” are in the estate for an accused topical product?
Based on the claim set you provided, there are at least two independent composition embodiments plus two method-of-use embodiments:
- Composition embodiment A: Claim 1 (broad solvent band; hydrophobe ≥24 C; emulsifier ≥0.05%; plus dependent melt/viscosity).
- Composition embodiment B: Claim 16 (solvent band narrower; hydrophobe ≥16 C; adds HLB 4-16; melt >35°C; stable).
- Use embodiment A: Claim 29 (apply embodiment A).
- Use embodiment B: Claim 30 (apply embodiment B).
Within each embodiment, risk also depends on whether a product uses:
- chlorhexidine digluconate at 0.05–5%, and
- an emollient system meeting the defined silicone-polyether copolymer template, or
- an emollient with specified solubility properties and total emollient loading (3–30%).
What patent landscape conclusions can be drawn from the claim language alone (without prosecution history or cited art)?
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The claim thesis is formulation science, not chlorhexidine chemistry.
The core limitation is the combination of a chlorhexidine salt in a hydroalcoholic vehicle with a specifically structured emulsifier and optional silicone-polyether emollient.
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The patent likely targets a formulation platform (surfactant architecture + vehicle + chlorhexidine).
Independent claims are not limited to a particular product form such as aerosol/gel/cream in your text; they are defined by composition parameters, melt temperature, viscosity, HLB, and stability.
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Two separate independent claims create two “lanes” for coverage.
Claim 1 is broader on solvent ratio and hydrophobe carbon count; claim 16 is narrower on solvent ratio and adds HLB/melt/stability requirements.
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Method claims create use-risk even for borderline formulations.
If any accused product aligns with claim 1 or claim 16, moisturizing-related marketing or instructions could engage claims 29/30.
Key Takeaways
- US 7,566,460 covers topical chlorhexidine salt compositions in hydroalcoholic solvents using emulsifiers with defined long-chain hydrophobic groups (≥24 C in claim 1; ≥16 C in claim 16) and specified hydrophilic groups (including EO/PO-bonded ether/ester structures).
- Claim 16 adds measurable constraints: HLB 4–16, melt temperature >35°C, and stability, which can narrow enforcement compared with claim 1.
- The strongest dependent anchors you provided are chlorhexidine digluconate at 0.05–5.0 wt% and a specific polyether/polysiloxane copolymer surfactant emollient structure.
- The estate includes two method-of-use claims tied to applying the claimed compositions for maintaining/improving skin moisture.
FAQs
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Does US 7,566,460 require a specific form factor (gel, spray, cream)?
The claim text you provided defines the product by composition parameters (solvent ratio, emulsifier loading/structure, salt concentration, performance metrics), not by a single named dosage form.
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Can a product avoid infringement by changing chlorhexidine to a different salt than diacetate/digluconate?
Claim 1/16 require “a chlorhexidine salt,” while the narrowing dependent claims explicitly cover diacetate/digluconate and especially chlorhexidine digluconate at 0.05–5%. Using a different chlorhexidine salt could avoid the dependent anchors.
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Which is easier to measure in a technical infringement analysis: emulsifier structure or HLB?
HLB and melt temperature are directly testable; the emulsifier structural features in the claims (hydrophobic carbon count, EO/PO bonding types, sorbitan/alkoxylation ranges) require chemical identification and characterization.
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If a formula matches claim 16 emulsifier architecture, can it still miss due to melt or stability?
Yes. Claim 16 expressly requires melt temperature >35°C and stable, separate from emulsifier structure.
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Do the method claims depend on therapeutic agent use beyond moisturizing?
Claims 29/30 focus on moisture maintenance/improvement by applying the claimed compositions. Claim 8/21 add a separate optional “therapeutic agent” concept, but the moisturizing method claim itself is not framed around a therapeutic agent.
References
No references included because the prompt did not provide the patent’s publication/filing details, prosecution history, or any external sources to cite beyond the claim text provided.
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