US Patent 8,962,000 Scope and Claims Analysis: O/W Microemulsion or Sub-Micron Emulsion Dermal Delivery Patent Landscape (US)
US Patent 8,962,000 claims a specific class of oil-in-water (O/W) microemulsion or sub-micron emulsion compositions and methods of dermal treatment using a staged formulation architecture: (i) an oil-phase microemulsion formed with defined oil and surfactant components, then (ii) addition of a non-surfactant amphiphilic co-solvent after formation, with a defined hydrophilic-to-lipophilic surfactant weight ratio and coverage for water-insoluble actives including corticosteroids and vitamin analogs. Claim 1 is the anchor; dependent claims narrow by surfactant HLB range, oil/occlusive composition, amphiphile identity, and corticosteroid species.
What this means commercially: the patent is structurally focused on a formulation “platform” with multiple claim handles (oil type, surfactant ratio and HLB, staged addition of amphiphile, and active class). That can constrain generic or follow-on reformulations, but it also creates multiple “design-around” variables that a challenger can exploit (ratio, co-solvent identity, surfactant system, and oil-phase composition).
What does US Patent 8,962,000 claim about O/W microemulsion dermal delivery?
Featured-snippet answer: The patent claims O/W microemulsion/sub-micron emulsion dermal delivery compositions where an oil-phase containing specified oil/surfactant components is dispersed in a water phase with hydrophilic surfactants and water, and a non-surfactant amphiphilic compound is added after microemulsion formation, with the hydrophilic surfactant:lipophilic surfactant weight ratio approximately 9:1 to 2:3, and with actives (including water-insoluble actives) located in the water phase or both phases.
Claim 1 (independent) scope: the core formulation architecture
Claim 1 recites these structural/functional limitations:
-
Delivery vehicle
- An oil-in-water microemulsion or sub-micron emulsion for dermal delivery.
-
Actives
- At least one pharmaceutically active ingredient.
- The active is present in the water phase or in both phases.
- The dependent claim set (8-10) further covers water-insoluble actives such as corticosteroids and vitamin analogs.
-
Oil-phase composition (dispersed oil phase)
- Oil phase comprises at least one component selected from:
- Animal oil
- Mineral oil
- Vegetable oil
- Silane
- Siloxane
- Ester
- Fatty acid
- Fat
- Halogen compound
- Alkoxylated alcohol
- Plus at least one lipophilic surfactant.
-
Water-phase composition (continuous phase)
- Water phase comprises:
- At least one hydrophilic surfactant
- Water
-
Post-formation addition of non-surfactant amphiphile
- A non-surfactant amphiphilic compound that is:
- added after formation of the microemulsion/sub-micron emulsion
- miscible in the water phase
-
Critical surfactant ratio
- The weight ratio of hydrophilic surfactant to lipophilic surfactant is:
- approximately 9.0:1.0 to 2.0:3.0
Claim 1 interpretation levers (what a court or examiner would focus on)
- “Added after formation”: This is a process timing limitation. If a competitor makes the same final composition but adds the amphiphile during formation, the challenger can argue non-infringement based on sequence.
- “Non-surfactant amphiphilic compound”: This excludes amphiphiles that are surfactants in the chemical definition sense. It is a key classification barrier.
- Ratio window (9:1 to 2:3): This is a measurable parameter. Design-around by shifting surfactant ratios outside the window is a direct infringement risk control.
How do dependent claims 2-10 narrow the microemulsion composition?
What does claim 2 require about occlusive agents and the oil phase?
Claim 2 adds:
- Oil phase comprises at least one occlusive agent selected from:
- Plus at least one lipophilic surfactant.
This tightens Claim 1 by limiting the occlusive components to two specific exemplars.
Claim 3: petrolatum + mineral oil mixture
Claim 3 requires:
- Oil phase comprises a mixture of petrolatum and mineral oil
- plus at least one lipophilic surfactant.
Claim 4: non-surfactant amphiphile identity class
Claim 4 limits the non-surfactant amphiphilic compound to:
- Water miscible organic solvent selected from:
- alcohol
- polyol
- mixtures thereof
Claims 5-7: surfactant aggregated HLB number
These introduce an additional quantitative constraint.
- Claim 5: aggregated HLB between 8.0 and 15.0
- Claim 6: between 10 and 12
- Claim 7: between 9.7 and 11.8
The “aggregated HLB” feature is both a strength (quantifiable) and a litigation hotspot (how it is calculated, which surfactants are included, and whether the competitor’s surfactant system can be shown to meet/exceed the range).
Claims 8-10: active ingredient class coverage
Claim 8:
- active is one or more water insoluble compounds selected from:
- corticosteroids
- vitamin D analogues
- vitamin A analogues
Claim 9:
- active is a corticosteroid
Claim 10:
- corticosteroid species:
- desonide
- clobetasol propionate
- betamethasone valerate
Scope effect: even if the broad formulation is used, the patent’s strongest direct match for value capture is when actives are in this corticosteroid/vitamin-analog class.
What method claims does US Patent 8,962,000 include for dermal treatment?
What does claim 11 cover as a method of treatment?
Claim 11 mirrors Claim 1 as a method-of-use:
- A method of medical or cosmetic treatment of a dermal condition.
- Applying to skin of a patient:
- an O/W microemulsion/sub-micron emulsion composition with the same:
- active presence in water phase or both phases
- oil-phase microemulsion architecture
- hydrophilic/lipophilic surfactant weight ratio 9:1 to 2:3
- post-formation addition of non-surfactant amphiphile miscible in water
Claim 12:
Practical risk: method claims can reach use of products even if manufacturing sequence arguments complicate product infringement theories. Still, the method claim includes the same formulation architecture as Claim 1, so non-infringement can still be pursued through product formulation differences.
How does claim 13 expand amphiphile options?
Claim 13 specifies the amphiphilic compound from Claim 4 can be:
- propylene glycol
- phenoxy ethanol
- mixtures thereof
This provides concrete formulation targets. If an accused product uses one of these, claim coverage is easier to map. If it uses a different water-miscible alcohol or polyol not captured by claim 13, the coverage may still exist under Claim 4, but claim 13 would not be available as a direct narrowing hook.
What additional limitation does claim 14 add for corticosteroid compositions?
Claim 14 adds specific architecture tied to corticosteroid actives:
- Composition for dermal delivery of at least one active that is:
- Oil phase comprises:
- petrolatum and at least one lipophilic surfactant
- Water phase comprises:
- hydrophilic surfactant and water
- Active location:
- corticosteroid in water phase or both phases
- Maintains the same surfactant weight ratio range.
Key point: Claim 14 is narrower than Claim 1 and overlaps with Claim 2/3 logic but is distinct by fixing the oil occlusive component to petrolatum rather than mineral oil as a necessary component.
What is the design-around surface for US 8,962,000?
This patent has multiple independent “knobs.” A competitor’s non-infringement analysis usually clusters around these:
1) Surfactant ratio design
- Target is hydrophilic surfactant : lipophilic surfactant weight ratio ~9:1 to 2:3.
- Moving outside the range is a direct product design lever.
2) “Aggregated HLB” design
- If surfactant system selection aims to avoid 8.0–15.0 (or tighter 9.7–11.8), you can reduce likelihood that dependent claims 5-7 apply.
- Litigation will turn on the calculation methodology.
3) Post-formation addition of amphiphile
- The amphiphile must be:
- added after microemulsion/sub-micron emulsion formation
- miscible in the water phase
- If a challenger prepares a “pre-mixed” system where the amphiphile is present during formation, infringement arguments based on sequence become weaker.
4) Amphiphile classification
- Must be a non-surfactant amphiphilic compound.
- A challenger can select a compound argued to be a surfactant (thus excluded) or not amphiphilic (thus excluded), depending on chemistry and characterization.
5) Oil phase occlusive composition
- Dependent claims narrow to mineral oil, petrolatum, or mixtures.
- Avoiding those components can move the case away from dependent claims 2-3 and 14.
6) Active choice
- Core Claim 1 is broad: any pharmaceutically active ingredient.
- But if the product uses non-listed active classes, mapping to dependent claims 8-10 may fall away, though Claim 1 can still cover if all structural formulation features match.
How strong is the patent estate around microemulsion composition and dermal method-of-use?
Strength drivers
- Clear measurable parameters:
- surfactant weight ratio window
- aggregated HLB ranges
- Process timing hook:
- Active class anchors:
- corticosteroids and listed species
- Duplicative coverage:
- independent product claim (1) plus method claim (11) with parallel formulation requirements.
Weakness drivers
- Breadth at Claim 1: the oil-phase “selected from” list is wide, but the combination of ratio + staged addition + amphiphile non-surfactant definition narrows in practice.
- Dependent claim dependency: design-around often attacks ratio or amphiphile timing and can knock out a large subset of dependent coverage.
- HLB dependence: if HLB calculation is contested, the dependent claims that use HLB ranges become litigation-sensitive.
What is the patent landscape for US 8,962,000: related claims and likely competing patents (framework for mapping)?
Because the prompt provides only the claim text and not the patent bibliographic metadata (assignee, filing date, IPC/CPC, specification examples, or cited art), a reliable, complete cross-patent landscape cannot be enumerated without risking factual errors. The scope can still be framed by the claim architecture, which maps to common adjacent IP clusters:
- Microemulsion dermal delivery formulations
- O/W systems, surfactant pairs, and co-solvent amphiphiles
- Surfactant ratio and HLB-targeted formulation patents
- aggregated HLB windows used to stabilize sub-micron dispersions
- Post-formation addition processes
- staged manufacturing methods to tune droplet size and phase behavior
- Corticosteroid topical microemulsions
- dermal delivery platforms for desonide, clobetasol propionate, betamethasone valerate
- Occlusive oil-phase variants
- petrolatum and mineral-oil variants for skin retention and irritation reduction
A defensible landscape analysis in litigation or licensing would require bibliographic data and citation analysis from the granted patent record, which is not provided here.
What do the claims imply about infringement risk for a competing topical corticosteroid product?
High-risk fact patterns
- Product is an O/W microemulsion or sub-micron emulsion for skin delivery.
- Uses a defined oil phase with lipophilic surfactant and a water phase with hydrophilic surfactant.
- Uses a non-surfactant amphiphilic co-solvent added after microemulsion formation, miscible in water (examples align with alcohols/polyols).
- Maintains hydrophilic:lipophilic surfactant weight ratio within ~9:1 to 2:3.
- If corticosteroid is desonide/clobetasol propionate/betamethasone valerate, dependent claim alignment improves.
Lower-risk fact patterns
- Surfactant ratio outside window.
- Amphiphile present before or during microemulsion formation (sequence mismatch).
- Amphiphile characterized as a surfactant or not amphiphilic.
- Oil phase avoids petrolatum/mineral oil combination tied to dependent claims.
- If using a different active class, dependent claims 8-10 may not map, though Claim 1 may still.
Key Takeaways
- US Patent 8,962,000 is a formulation-centric patent covering O/W microemulsion/sub-micron emulsion dermal delivery with:
- defined oil-phase component types plus lipophilic surfactant
- defined water phase with hydrophilic surfactant and water
- post-formation addition of a non-surfactant amphiphilic water-miscible co-solvent
- hydrophilic:lipophilic surfactant weight ratio ~9:1 to 2:3
- Dependent claims add occlusive oil phase restrictions (mineral oil/petrolatum), amphiphile identity (propylene glycol, phenoxy ethanol), and aggregated HLB ranges (up to a tight 9.7 to 11.8).
- The patent’s strongest direct mapping for commercial topical products is with corticosteroids, including desonide, clobetasol propionate, and betamethasone valerate.
- Design-around opportunities concentrate on:
- surfactant ratio
- aggregated HLB window
- the “added after formation” sequence
- amphiphile classification
- occlusive oil-phase composition.
FAQs
What surfactant ratio is required to fall within US 8,962,000 Claim 1?
Hydrophilic surfactant to lipophilic surfactant is approximately 9.0:1.0 to 2.0:3.0 by weight.
Does US 8,962,000 require the amphiphilic compound to be present after microemulsion formation?
Yes. Claim 1 requires a non-surfactant amphiphilic compound that is added after formation and is miscible in the water phase.
Which corticosteroids are explicitly named in dependent claims?
Desonide, clobetasol propionate, and betamethasone valerate.
What aggregated HLB range is claimed?
Dependent claims include aggregated HLB between 8.0 and 15.0 (Claim 5), 10 and 12 (Claim 6), and 9.7 and 11.8 (Claim 7).
Is the patent limited to medical dermal treatment or does it cover cosmetic use?
Claim 11 covers medical or cosmetic treatment of dermal conditions via application to skin.
References (APA)
- United States Patent 8,962,000. (n.d.). Oil-in-water microemulsion or sub-micron emulsion compositions for dermal delivery and methods of use.
