United States Drug Patent 8,722,021: Claim Scope, Patent Strength, Exclusivity and Competitive Landscape

United States Patent No. 8,722,021 protects a platform for foamable pharmaceutical and personal-care compositions. Its core requirements are a surfactant, an organic solvent, a polymeric stabilizer or foam adjuvant, and a propellant that produces a foam remaining stable for at least 60 seconds at 37°C. The patent does not claim a single active ingredient or disease indication. Its commercial value therefore depends on whether a marketed product practices the formulation limitations and whether related continuation patents provide additional protection.

The strongest claim group is the three independent composition claims: claims 1, 21 and 22. Claims 1 and 21 are materially different formulation architectures. Claim 1 covers a water-containing carrier with a broad organic-solvent category. Claims 21 and 22 focus on hydrophobic organic solvents at 70% to 99% of the carrier and use a polymeric agent or foam adjuvant as the stabilizer.

What does United States Patent 8,722,021 protect?

The patent protects a foamable composition that satisfies both structural and performance limitations:

A carrier.
A liquefied or compressed-gas propellant.
A specified surfactant concentration.
An organic solvent or hydrophobic organic solvent.
A polymeric agent or foam adjuvant.
Foam formation after dispensing.
Foam stability for at least 60 seconds at 37°C.

The temperature and duration requirement is central. A composition that contains the listed excipients but collapses before the required stability period may fall outside the claims.

The patent is a formulation-platform patent rather than an active-ingredient patent. It covers compositions containing antibacterial, antifungal, corticosteroid, retinoid, hormone, anesthetic, antiviral and other active agents, but it does not require any active agent in independent claim 1, 21 or 22.

How many independent claims does US 8,722,021 have?

The patent has three independent composition claims.

Claim	Core formulation	Principal quantitative limitations
1	Water-containing carrier with organic solvent and polymeric agent	Surfactant 0.1%-5%; organic solvent 2%-75%; polymeric agent 0.01%-5%; foam stable at least 60 seconds at 37°C
21	Hydrophobic-solvent carrier	Surfactant 0.1%-5%; hydrophobic organic solvent 70%-99%; polymeric agent 0.01%-5% or foam adjuvant 0.1%-5%
22	Hydrophobic-solvent carrier with broader surfactant range	Surfactant 0.2%-15%; hydrophobic organic solvent 70%-99%; polymeric agent 0.01%-5% or foam adjuvant 0.1%-5%

Claim 1 is the broadest practical entry point because it requires water but allows the organic solvent to range from 2% to 75% of the carrier. Claims 21 and 22 are narrower in solvent composition but may capture substantially anhydrous or highly hydrophobic formulations that do not satisfy claim 1.

What are the key limitations of independent claim 1?

Claim 1 has four principal technical limitations.

Surfactant requirement

The carrier must contain approximately 0.1% to 5% by weight of a surface-active agent. Dependent claims narrow this range to less than about 2% and identify nonionic, cationic, amphoteric and ionic surfactants.

Claim 15 limits the surfactant to a nonionic surfactant. Claim 17 lists specific examples, including polysorbates, sorbitan esters, polyoxyethylene compounds, glyceryl monostearate, lecithin, sodium lauryl sulfate and cocamidopropyl betaine.

A formulation using a different surface-stabilizing technology may avoid literal infringement if the surfactant limitation is absent. The doctrine of equivalents could still be relevant, but the specific numerical ranges may restrict that argument.

Organic-solvent requirement

The organic solvent must be present at approximately 2% to 75% of the carrier. The claim identifies emollients, polar solvents, oils and mixtures. Claim 4 adds essential oils.

Claim 18 creates a subgenus in which more than 50% of the carrier is a potent solvent. Claim 19 lists polyethylene glycol, propylene glycol, glycerol, benzyl alcohol, dimethyl sulfoxide, N-methylpyrrolidone, dimethyl isosorbide, glycofurol and ethoxydiglycol.

The overlap between claims 1 and 18 is commercially significant. A formulation containing 50% to 75% potent solvent can satisfy both claim 1 and claim 18 if all other limitations are present.

Polymeric-agent requirement

The polymeric agent must be approximately 0.01% to 5% of the carrier. The claim covers bioadhesive, gelling, film-forming and phase-change polymers.

Claim 12 lists a broad polymer universe, including cellulose derivatives, carbomers, polyvinylpyrrolidone, polyvinyl alcohol, alginates, xanthan gum, guar gum, carrageenan, polyacrylic acid polymers and crosslinked acrylic acid/alkyl acrylate polymers such as Pemulen.

Claim 8 narrows the polymer concentration to less than about 1%. This limitation may be commercially important because many topical foams use low polymer concentrations to preserve spreadability and reduce residue.

Foam-stability requirement

The foam must remain stable for at least 60 seconds at 37°C. Claim 23 extends the limitation to at least two or three minutes.

This functional limitation can create both strength and enforcement issues. It captures the performance characteristic that distinguishes the claimed compositions from unstable aerosol or emulsion systems. It also creates potential disputes over:

The dispensing device.
Foam volume and collapse measurement.
Whether “stable” means visual persistence or a quantified collapse threshold.
The time at which testing begins.
Temperature control at 37°C.
The effect of active ingredient loading.
Whether stability must be measured on every batch.

A competitor may design around the claim by using a composition that forms a foam but does not remain stable for the required period, although that strategy may undermine product usability.

How do claims 21 and 22 differ from claim 1?

Claims 21 and 22 cover a different formulation architecture.

Both require a hydrophobic organic solvent at approximately 70% to 99% of the carrier. They also require a stabilizer selected from either:

A polymeric agent at approximately 0.01% to 5%; or
A foam adjuvant at approximately 0.1% to 5%.

Claim 22 has a broader surfactant range, from approximately 0.2% to 15%, compared with 0.1% to 5% in claim 21.

Issue	Claim 1	Claim 21	Claim 22
Water expressly required	Yes	No	No
Organic solvent	2%-75%	Hydrophobic solvent 70%-99%	Hydrophobic solvent 70%-99%
Surfactant	0.1%-5%	0.1%-5%	0.2%-15%
Polymeric agent	Required	Alternative stabilizer	Alternative stabilizer
Foam adjuvant	Not required	Alternative to polymer	Alternative to polymer
Stability	At least 60 seconds at 37°C	At least 60 seconds at 37°C	At least 60 seconds at 37°C

Claims 21 and 22 may be particularly relevant to oil-rich, water-poor or anhydrous foam products. They also appear less dependent on the water limitation in claim 1.

What formulations are protected by the dependent claims?

The dependent claims expand the patent across several formulation and therapeutic categories.

Microemulsions and nanoparticles

Claims 5 and 6 cover carriers containing microemulsions or nanoparticles. These claims extend the platform beyond conventional bulk emulsions and may reach formulations designed to improve solubility, penetration, residence time or delivery to mucosal tissue.

The claims do not require a particular particle size, composition, encapsulation technology or release profile. In an infringement analysis, the meaning of “nanoparticles” and “micro-emulsion” would likely depend on the specification and prosecution record.

Foam adjuvants

Claim 13 covers fatty alcohols and fatty acids used to stabilize or modify foam. The list includes cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, stearic acid, behenic acid, octacosanoic acid and 12-hydroxystearic acid.

Claim 16 limits the combined amount of foam adjuvant, surfactant and gelling agent to less than about 8% of the carrier. This creates a low-excipient subgenus that may be relevant to products designed for rapid absorption or reduced residue.

Low-alcohol systems

Claim 11 covers formulations containing less than about 2% of lower alcohols with up to five carbon atoms. This limitation is relevant to products designed to reduce stinging, drying or irritation associated with ethanol, isopropanol and related solvents.

Azole antifungal systems

Claims 25 through 27 cover azoles, including clotrimazole, econazole, fluconazole, ketoconazole, itraconazole, metronidazole and miconazole.

These claims do not limit the composition to a particular dose, indication, concentration or dosage form beyond the foamable-composition limitations inherited from the parent claims. A product containing an azole therefore requires analysis of the formulation elements, not merely the presence of the antifungal ingredient.

What is the likely infringement test for a competing foam?

A competing product would generally be evaluated element by element against each asserted claim. For claim 1, the analysis would include:

Element	Key question
Carrier	Does the product have a carrier separate from the propellant?
Propellant	Does it use a liquefied or compressed gas?
Surfactant	Is a surface-active agent present at 0.1%-5%?
Organic solvent	Is an emollient, polar solvent, oil or mixture present at 2%-75%?
Polymer	Is a covered polymer present at 0.01%-5%?
Foam formation	Does dispensing produce a foam?
Stability	Does the foam remain stable for at least 60 seconds at 37°C?

The phrase “by weight of the carrier” matters. Concentrations calculated against the total packaged composition, including propellant, may not match the claim’s denominator. A product can fall within or outside a numerical limitation depending on how the formulation is measured and how the carrier is defined.

The propellant limitation also matters. A pump dispenser that mechanically aerates a liquid without using a liquefied or compressed gas may avoid the express propellant requirement, subject to any broader claim in a related patent family.

When does US 8,722,021 lose exclusivity?

The patent’s enforceable term must be determined from the USPTO patent record, including the effective filing date, patent-term adjustment, terminal disclaimers and any applicable patent-term extension. The grant date was May 13, 2014. Patent expiration cannot be calculated reliably from the grant date alone. Under 35 U.S.C. § 154, a United States utility patent generally receives a term measured from the effective nonprovisional filing framework, subject to adjustments and disclaimers.

The patent is therefore not properly analyzed as a simple “20 years from grant” patent. A commercial freedom-to-operate opinion should use the USPTO Patent Center term data and the complete prosecution history rather than a nominal estimate. [United States Patent and Trademark Office, n.d.; 35 U.S.C. § 154]

Does US 8,722,021 have Orange Book protection?

The claim text does not establish Orange Book listing. The Orange Book lists patents submitted by sponsors for approved drug products, including patents covering drug substances, drug products and approved methods of use. A broad formulation patent may be listed only if it meets FDA listing requirements and is submitted for a specific approved product.

Because US 8,722,021 does not require a particular active ingredient, it is not automatically an Orange Book patent for every drug that uses a covered foam. A product-specific Orange Book analysis must identify:

The approved drug product.
The NDA holder.
The active ingredient.
The product formulation.
Any submitted formulation or method-of-use patent.
The FDA publication and delisting history.

The patent number alone does not establish an Orange Book listing or a Paragraph IV challenge. [FDA, 2024]

What Paragraph IV and generic-entry risks exist?

A Paragraph IV certification is relevant only when a generic applicant references an NDA product with listed patents. The broad composition claims create several potential entry scenarios:

Scenario 1: Same active ingredient, different vehicle

A generic could use the same drug but change the solvent, surfactant, polymer or propellant. This is the clearest design-around path if the alternative formulation avoids one required quantitative range.

Scenario 2: Same vehicle, different foam performance

A product could use similar excipients but fail the claimed 60-second stability test. This may reduce infringement exposure but could create regulatory or commercial comparability issues.

Scenario 3: Mechanical foaming

A pump-generated foam without a liquefied or compressed-gas propellant may avoid the express propellant limitation. Related patents may still cover the device or dispensing system.

Scenario 4: Hydrophobic formulation

A highly hydrophobic carrier containing 70% to 99% hydrophobic organic solvent may implicate claims 21 and 22 even if it avoids claim 1’s water requirement.

Scenario 5: Different stabilizer system

A competitor may use proteins, particles, inorganic stabilizers or a device-based stabilization mechanism that does not fall within the claimed polymeric-agent or foam-adjuvant categories.

No conclusion about a specific Paragraph IV filing, generic challenger or litigation outcome follows from the supplied claim text alone.

Which companies are relevant to the commercial landscape?

The patent’s technical scope is associated with pharmaceutical foam technology rather than a single active ingredient. The relevant commercial landscape includes companies developing topical, dermatological, gynecological, mucosal and antifungal foams, together with manufacturers of aerosol containers, propellant systems and foam dispensers.

The patent can affect:

Topical dermatology products.
Vaginal and mucosal delivery systems.
Antifungal and antibacterial foams.
Corticosteroid and retinoid foams.
Hormonal and contraceptive foams.
Anhydrous or oil-rich foam platforms.
Products using carbomers, cellulose polymers, fatty alcohols or polysorbates.

A company may practice the patent without listing it in product labeling, and a product may be protected by separate continuation, formulation, device or method-of-use patents. The patent should therefore be treated as one layer of a broader portfolio, not as the complete exclusivity position for a commercial product.

How strong is the patent estate based on the claims?

The patent has meaningful breadth but several identifiable pressure points.

Strengths

Three independent composition claims.
Coverage of both water-containing and hydrophobic carrier architectures.
Broad active-agent categories.
Extensive surfactant and polymer lists.
Protection for microemulsions and nanoparticles.
Objective concentration ranges.
A performance limitation tied to foam persistence at physiological temperature.
Coverage of both polymeric agents and fatty foam adjuvants in claims 21 and 22.

Weaknesses

The claims are formulation-dependent and require matching multiple quantitative ranges.
The foam-stability test may require factual and expert evidence.
Broad excipient categories may face written-description, enablement or construction disputes depending on the specification and prosecution history.
The patent does not by itself protect a particular active ingredient, indication or clinical outcome.
A device-generated foam without the claimed propellant may provide a design-around route.
Related patents may carry the practical exclusivity after this patent expires or is narrowed.

Overall, the claims are strongest against products that deliberately reproduce the disclosed foam architecture, particularly low-surfactant systems with a covered polymer or fatty alcohol and demonstrated stability at 37°C.

What patent litigation or settlement agreements affect US 8,722,021?

The supplied claims do not identify litigation, settlements, terminal disclaimers or post-grant proceedings. Those issues cannot be inferred from the claim language. The relevant legal records are the USPTO prosecution file, Patent Trial and Appeal Board database, PACER docket history and any Federal Circuit decisions involving the patent or its continuations.

A litigation review should distinguish:

Direct infringement litigation.
ANDA litigation under the Hatch-Waxman Act.
Inter partes review.
Post-grant review.
Reexamination.
Ownership or assignment disputes.
License agreements.
Settlement agreements containing launch dates or covenants not to sue.

Key Takeaways

US 8,722,021 is a broad foam-composition patent, not a single-drug patent.
Claims 1, 21 and 22 are the principal independent claims.
Claim 1 covers water-containing carriers with 2% to 75% organic solvent.
Claims 21 and 22 cover carriers containing 70% to 99% hydrophobic organic solvent.
Surfactants, polymers, fatty alcohols and foam stability at 37°C are central limitations.
Claims 25 through 27 create specific azole antifungal subgroups.
The patent does not automatically have Orange Book status.
Paragraph IV risk depends on an approved NDA product and a submitted patent listing.
Patent term must be calculated from USPTO term data, not the 2014 grant date alone.
The principal design-around options involve the propellant, stabilizer, solvent range, surfactant range and foam-stability performance.

FAQs about US Patent 8,722,021

Does the patent cover every pharmaceutical foam?

No. The foam must satisfy the claimed propellant, excipient, concentration and stability limitations. A mechanically aerated foam or a foam using a different stabilization system may fall outside the claims.

Does the patent cover clotrimazole foam automatically?

No. Clotrimazole is covered only through dependent claims when the complete formulation also satisfies the inherited limitations of the relevant parent claim.

Can a product infringe without containing water?

Yes, potentially. Claims 21 and 22 do not expressly require water and focus on hydrophobic organic solvents at 70% to 99% of the carrier.

Is a pump foam outside the patent?

Not automatically. The claims require a liquefied or compressed-gas propellant. A pump that uses compressed gas may still satisfy that limitation, while a purely mechanical pump may not.

Does foam lasting two minutes infringe more claims than foam lasting one minute?

Potentially. A foam lasting two or three minutes may satisfy claim 23 or claim 24 in addition to the underlying independent claim, provided every other limitation is met.

References

Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.

United States Code. (2024). 35 U.S.C. § 154: Contents and term of patent; provisional rights.

United States Patent and Trademark Office. (2014). United States Patent No. 8,722,021: Foamable compositions and methods of use thereof. U.S. Department of Commerce.

United States Patent and Trademark Office. (n.d.). Patent Center. U.S. Department of Commerce.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Israel	152486	Oct 25, 2002

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2003279493	⤷ Start Trial
Australia	2004261063	⤷ Start Trial
Australia	2004266502	⤷ Start Trial
Australia	2004313285	⤷ Start Trial
Australia	2004321183	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: 8,722,021