US Patent 8,026,238: Claim Scope, Expiration, Orange Book Status, and Antifungal Foam Patent Landscape

US Patent 8,026,238 covers topical antifungal foams and mousses that use ethanol or another lower alcohol, water, surfactants, long-chain alcohols, and, in several claim sets, a hydrocarbon propellant. The commercial core is a low-residue, temperature-sensitive, quick-breaking foam containing an imidazole or triazole antifungal, with ketoconazole expressly claimed.

The patent has 54 claims, but the claims repeat a limited number of technical combinations. Its strongest commercial coverage is directed to ketoconazole formulations containing more than 50% ethanol, up to 5% surfactant, up to 5% cetyl or stearyl alcohol, up to 10% propylene glycol, and water. The patent does not claim ketoconazole as a molecule. It claims a particular topical delivery system and methods of using that system.

Based on its 2011 issue date and the patent family’s early-2000s priority structure, the ordinary US patent term would have ended in 2024, subject to any patent-term adjustment or other recorded term extension. A current freedom-to-operate analysis must therefore confirm the USPTO term calculation and whether any continuation or related patent remains enforceable.

What does US Patent 8,026,238 protect?

The patent protects four linked technical concepts:

An antifungal active selected from imidazoles or triazoles.
A topical foam or mousse that breaks rapidly after application and is temperature-sensitive.
A solvent and excipient system centered on a lower alcohol, especially ethanol, water, surfactant, and long-chain alcohol.
Low residual non-volatile content and, in certain claims, controlled hydrocarbon propellant content.

The independent claims divide into method claims and composition claims.

Claim group	Independent claims	Principal subject matter
Treatment methods with broad foam limitations	1, 21, 49, 52	Applying an antifungal foam or mousse to skin to achieve epidermal or upper-skin penetration
Broad composition claims	7, 32, 50, 53	Antifungal, surfactant, alcohol, water, long-chain alcohol, foam, and residual-solids limitations
Defined ethanol compositions	15, 19, 43, 47, 51, 54	More than 50% and up to 90% ethanol, low surfactant and long-chain alcohol levels, water, and in some claims propellant
Narrow species claims	5, 13, 16, 20, 30, 41, 44, 48	Ketoconazole
Narrow excipient claims	17, 18, 45, 46	Polysorbate-type surfactants and cetyl or stearyl alcohol

The “consisting essentially of” language is material. It generally permits additional ingredients that do not materially alter the basic and novel characteristics of the claimed formulation, while excluding ingredients that would materially change the foam, delivery, volatility, or penetration properties.

What are the broadest independent claims?

Claim 1: antifungal treatment method

Claim 1 requires:

a topical, foamable composition;
a temperature-sensitive, quick-breaking foam or mousse;
an imidazole or triazole antifungal;
an antifungal capable of penetrating upper skin layers;
at least one surfactant;
water;
a lower alcohol;
a long-chain alcohol;
residual non-volatile content below 25%;
hydrocarbon gas propellant below 60%;
antifungal dissolved in the lower alcohol; and
application to skin for sufficient retention and penetration.

This claim is broad in active ingredient class but narrow in formulation architecture. A product that uses ketoconazole but lacks a required element, such as the specified foam behavior, lower alcohol dissolution, or long-chain alcohol, would not literally meet claim 1.

Claim 7: broad composition claim

Claim 7 covers a topical foam containing:

an imidazole or triazole;
a surfactant;
more than 50% lower alcohol;
water;
long-chain alcohol;
less than 25% residual non-volatile material; and
a propellant.

It also requires the antifungal to be dissolved in ethanol and the product to produce a temperature-sensitive quick-breaking foam or mousse. The claim text refers to ethanol in the dissolution limitation even though the broader composition language identifies the lower alcohol separately. That drafting structure creates an important limitation: a formulation using isopropanol or another lower alcohol may not satisfy every limitation of claim 7.

Claim 15 and claim 19: defined ethanol systems

Claims 15 and 19 are among the most commercially relevant claims. They require:

up to 5% antifungal;
ethanol above 50% and up to 90%;
up to 5% surfactant;
up to 5% long-chain alcohol;
up to 10% propylene glycol; and
5% to 95% water.

Claim 19 narrows the surfactant to polyoxyethylene sorbitan monostearate and the long-chain alcohol to cetyl alcohol, stearyl alcohol, or mixtures. Claim 20 further narrows the active to ketoconazole.

A ketoconazole foam with the following architecture is therefore within the central literal scope of claims 19 and 20 if the remaining functional and compositional limitations are met:

Component	Claimed range or identity
Ketoconazole or other imidazole/triazole	Up to 5%
Ethanol	More than 50% to 90%
Polyoxyethylene sorbitan monostearate	Up to 5%
Cetyl alcohol, stearyl alcohol, or mixture	Up to 5%
Propylene glycol	Up to 10%
Water	5% to 95%

How do the propellant and residual-solids claims operate?

Claims 21 through 42 create a second claim family focused on volatile formulation behavior.

The principal thresholds are:

Limitation	Claims
Lower alcohol above 10%	21, 32 and dependents
Lower alcohol above 50%	26, 37
Residual non-volatile content below 25%	21, 32
Residual non-volatile content below 10%	22, 33
Residual non-volatile content below 6%	23, 34
Hydrocarbon propellant below 60%	21, 32
Hydrocarbon propellant below 10%	24, 35
Hydrocarbon propellant up to 20% in a defined formula	25, 36
Alcohol-to-water ratio of approximately 1.65:1	28, 39

The residual non-volatile limitation is a key point of infringement analysis. It is not equivalent to total excipient content. A party would need to determine which formulation components remain after evaporation under the patent’s relevant test methodology. Long-chain alcohol, surfactant, propylene glycol, antifungal, and other non-volatile ingredients may contribute to the residual fraction.

The approximately 1.65:1 alcohol-to-water ratio in claims 28 and 39 is narrower than the broader percentage ranges. A product can fall within the percentage limitations while avoiding the ratio limitation, or satisfy the ratio while failing another required limitation.

What formulations are most directly covered?

The highest-overlap formulation is a ketoconazole mousse with the following features:

ketoconazole at no more than 5%;
ethanol above 50% and no more than 90%;
water;
polysorbate 60, identified in the claims as polyoxyethylene sorbitan monostearate;
cetyl alcohol, stearyl alcohol, or both;
propylene glycol at no more than 10%;
less than 10% hydrocarbon propellant;
residual non-volatile content below 6% or 10%; and
temperature-sensitive, quick-breaking foam behavior.

Claims 43 through 48 add a narrower water range of 5% to 34% and propellant below 10%. Claims 47 and 48 are particularly narrow because they combine the ethanol, polysorbate 60, long-chain alcohol, propylene glycol, water, propellant, and ketoconazole limitations.

These claims are technically narrower but potentially stronger against a close commercial copy because they describe a recognizable formulation fingerprint.

What is the scope of the ketoconazole claims?

Ketoconazole is expressly recited in dependent claims 5, 13, 16, 20, 30, 41, 44, and 48. The independent claims remain broader because they cover imidazole and triazole compounds as classes.

The patent therefore has two levels of active-ingredient coverage:

Active-ingredient level	Scope
Class level	Imidazole or triazole compounds
Species level	Ketoconazole

The class claims may cover econazole, miconazole, clotrimazole, oxiconazole, sertaconazole, bifonazole, and selected triazoles if the compound falls within the claim construction of “imidazole compound” or “triazole compound” and the remaining formulation requirements are met. The claims do not automatically cover every antifungal foam. The active must be integrated into the claimed alcohol-water-surfactant-long-chain-alcohol system and satisfy the foam and residue limitations.

How strong is the patent estate?

The estate is strongest against formulations that copy the complete excipient and physical-performance profile. Its practical strengths are:

multiple independent composition claims;
separate treatment-method claims;
alternative alcohol thresholds above 10% and above 50%;
alternative residual-solids thresholds below 25%, 10%, and 6%;
separate propellant thresholds below 60% and below 10%;
specific coverage of ethanol;
specific coverage of ketoconazole;
specific coverage of polysorbate 60;
specific coverage of cetyl and stearyl alcohol; and
a defined alcohol-to-water ratio.

Its limitations are equally important:

the claims are formulation-dependent;
many claims require a foam that is temperature-sensitive and quick-breaking;
“retained in or on skin” and “sufficient to penetrate the epidermis” may create proof issues;
“consisting essentially of” can create disputes over added ingredients;
percentage ranges can be avoided through formulation redesign;
the patent does not cover oral, injectable, or non-foam topical ketoconazole products;
it does not claim the active ingredient itself.

A competitor could pursue a design-around using a different vehicle, a non-hydrocarbon propellant, a non-foam cream or gel, a lower ethanol concentration, a different surfactant, a different long-chain fatty alcohol, or a different active ingredient. Whether that avoids infringement depends on the particular claim and on equivalents analysis.

When does US Patent 8,026,238 lose exclusivity?

The patent issued in 2011. Under 35 U.S.C. §154, the ordinary term for a US utility patent is generally 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment and certain extensions (35 U.S.C. §154).

The family’s ordinary term appears to have reached its endpoint in 2024 based on its early-2000s priority structure. The operative date for enforcement is the USPTO-recorded expiration date, not the issue date. A patent-term adjustment could move the date modestly, while a patent-term extension would require an applicable regulatory basis under 35 U.S.C. §156.

For commercial diligence, the relevant distinction is:

Question	Result
Is the 2011 issue date the expiration date?	No
Does the patent ordinarily run 20 years from issuance?	No
Is the patent likely beyond its ordinary term by 2025?	Yes
Can a related continuation remain relevant?	Yes
Does expiration eliminate risk from other formulation patents?	No

The patent number alone does not establish that all related Foamix or topical-foam patents have expired. Continuations, divisionals, or patents claiming different formulations may have later expiration dates.

What is the Orange Book status of US Patent 8,026,238?

A patent is not an Orange Book patent merely because it covers an FDA-approved topical formulation. The FDA lists patents submitted by an NDA holder when they meet the applicable listing requirements for the approved drug product (FDA, 2024).

The Orange Book analysis must be performed at the product level:

Identify the approved antifungal foam NDA.
Review the current patent listing for that NDA.
Determine whether US 8,026,238 is listed.
Check whether the listing was withdrawn, expired, delisted, or superseded.
Review any associated pediatric exclusivity or regulatory exclusivity.

A formulation patent covering ketoconazole foam can be relevant to an ANDA even if the active ingredient is old. If listed, it could support a Paragraph IV certification. If not listed, a generic applicant may still face ordinary patent litigation, but the Orange Book certification and 30-month-stay framework would differ.

Are there Paragraph IV challenges or generic launch risks?

The relevant generic product would likely be an ANDA for a topical ketoconazole foam or mousse, not a conventional ketoconazole cream or shampoo. The principal Paragraph IV risk would arise from an ANDA product that reproduces:

more than 50% ethanol;
ketoconazole;
polysorbate 60 or a substantially similar surfactant;
cetyl or stearyl alcohol;
propylene glycol;
water;
hydrocarbon propellant;
low residual non-volatile content; and
quick-breaking foam behavior.

A generic could attempt a non-infringement position by changing one or more of these parameters. The commercial risk is therefore highest for a close generic equivalent and lower for a different dosage form.

The likely launch scenarios are:

Scenario	Patent exposure
Ketoconazole cream or gel	Low exposure to these claims because the product is not a foam or mousse
Ketoconazole shampoo	Generally outside the claimed foam architecture
Ketoconazole aerosol mousse copying the excipient profile	High exposure if the patent remains enforceable
Non-ethanol antifungal foam	May avoid ethanol-specific claims but could encounter broader lower-alcohol claims
Foam using a different propellant and different residue profile	Potential design-around, subject to remaining claim limitations
Product launched after confirmed patent expiration	No infringement liability for the expired patent, but later-family patents must be checked

What patent litigation and settlement issues matter?

The supplied claim text does not identify a litigation docket, settlement agreement, or Paragraph IV notice. Those issues cannot be inferred from the claims themselves.

For diligence, the relevant records are:

USPTO Patent Center prosecution and maintenance records;
PACER and district-court docket records;
FDA Orange Book patent listings;
FDA Paragraph IV notice disclosures where available;
PTAB proceedings;
assignment and licensing records; and
any settlement agreement filed under the Medicare Modernization Act reporting process.

A settlement involving a related Foamix patent would not necessarily resolve US 8,026,238 unless the agreement expressly covers this patent, its claims, or the relevant product.

Which companies and products are most relevant?

The patent landscape centers on three groups:

Originator and formulation-platform companies

Foamix and companies commercializing Foamix-developed topical foam technology are the most relevant patent stakeholders because the claimed platform is directed to foam generation, rapid break, skin retention, and low-residue delivery.

Generic manufacturers

Potential challengers include manufacturers pursuing topical antifungal foams through the ANDA pathway. Their risk depends on the reference-listed drug, the proposed formulation, Orange Book listings, and whether the product is pharmaceutically equivalent or therapeutically substitutable.

Competing antifungal products

Conventional creams, gels, shampoos, lotions, and solutions are competitive products but generally do not reproduce the claimed foam architecture. Their existence limits the commercial blocking power of the patent because physicians and consumers can often use alternative dosage forms.

What licensing or manufacturing barriers does the patent create?

The claims can create practical barriers beyond the active ingredient:

aerosol can and valve compatibility;
hydrocarbon propellant handling;
foam stability and temperature response;
controlled evaporation;
antifungal solubilization in ethanol;
low-residue manufacturing;
reproducible particle or droplet delivery;
scale-up of surfactant and fatty-alcohol systems; and
analytical methods for residual non-volatile content.

A license may be commercially useful where a competitor wants to copy the formulation platform without developing a materially different foam system. The patent itself does not establish that a license was granted, nor does it identify royalty terms or field-of-use restrictions.

Key Takeaways

US 8,026,238 covers antifungal topical foams and mousses, not ketoconazole as a molecule.
The commercial center of gravity is an ethanol-rich, low-residue formulation containing water, surfactant, long-chain alcohol, and, in several claims, hydrocarbon propellant.
Ketoconazole, polysorbate 60, cetyl alcohol, stearyl alcohol, and propylene glycol are expressly claimed in narrower combinations.
Independent claims cover both treatment methods and compositions.
Residual non-volatile content thresholds below 25%, 10%, and 6% are central limitations.
The patent’s ordinary term appears to have ended in 2024 based on its early-2000s priority structure, subject to the USPTO-recorded term calculation.
A current generic-entry analysis must separately review continuations, related Foamix patents, Orange Book listings, and product-specific litigation.
The most exposed product is a close ketoconazole aerosol mousse that reproduces the claimed ethanol, surfactant, fatty-alcohol, propylene-glycol, water, propellant, and low-residue profile.

FAQs

Does US Patent 8,026,238 cover ketoconazole cream?

No. The claims require a topical foamable composition or a method using such a composition. A conventional ketoconazole cream would generally lack the claimed foam or mousse limitations.

Can a triazole antifungal infringe this patent?

Yes. The independent claims cover antifungal agents selected from imidazole and triazole compounds. The formulation and foam limitations must also be satisfied.

Is polysorbate 60 specifically claimed?

Yes. Claims 17, 19, 45, and 51 identify polyoxyethylene sorbitan monostearate, commonly known as polysorbate 60, as a claimed surfactant.

Does changing the hydrocarbon propellant avoid infringement?

Not necessarily. Some claims require a hydrocarbon propellant, but other claims do not expressly require a particular propellant amount or type. The full claim set must be compared with the redesigned formulation.

Does patent expiration eliminate all ketoconazole foam patent risk?

No. Expiration of US 8,026,238 would eliminate infringement liability for that patent but would not eliminate risk from continuation patents, later formulation patents, method-of-use patents, regulatory exclusivity, or other third-party rights.

References

U.S. Patent No. 8,026,238. (2011). Topical foamable compositions and methods for treating fungal diseases. United States Patent and Trademark Office.
United States Code. (2024). 35 U.S.C. § 154, contents and term of patent; § 156, extension of patent term.
United States Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA.
United States Patent and Trademark Office. (2024). Patent Center and patent term adjustment records. USPTO.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Australia	PO9838	Oct 17, 1997
Australia	PP1217	Jan 06, 1998

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	346588	⤷ Start Trial
Australia	732456	⤷ Start Trial
Australia	9728898	⤷ Start Trial
Canada	2306560	⤷ Start Trial
Germany	69836555	⤷ Start Trial
Denmark	1024792	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,026,238

Summary for Patent: 8,026,238