United States Patent 9,675,639: Claim Scope, Expiration, Orange Book Status, and Hydrogen Peroxide Patent Landscape

US Patent 9,675,639 protects topical compositions combining high-concentration hydrogen peroxide with 2-propanol, particularly formulations containing approximately 40% or 45% hydrogen peroxide and 5% 2-propanol. The patent also covers selected stabilizers, gelling agents, surface-tension properties, release characteristics, redox potential, pH, storage stability, lesion-treatment methods, dosing schedules, and specialized applicators.

The broadest practical commercial coverage is concentrated in claims 1, 13-16, 38-50, 51, 54, 60-70. A competing product containing 25%-70% hydrogen peroxide and 1%-5% 2-propanol could potentially fall within the independent composition claims even if it avoids the narrower formulation, pH, surface-tension, or applicator limitations.

The patent issued June 20, 2017, from an application claiming priority to a March 15, 2013 provisional filing. On a conventional 20-year term calculation from the nonprovisional filing date, the base expiration date is expected to fall in March 2034, subject to patent-term adjustment, terminal disclaimers, and maintenance-fee status. [1]

What does US Patent 9,675,639 protect?

The patent has three principal claim groups:

Claim group	Claims	Protected subject matter
Composition claims	1-50	Hydrogen peroxide and 2-propanol topical formulations
Treatment-method claims	51-70	Administration of the formulations to skin lesions and conditions
Applicator-related method claims	62-66	Use of a frangible ampoule, filter, applicator body, hub, and tip

The central technical concept is a high-strength hydrogen peroxide formulation modified with 2-propanol. The 2-propanol is claimed as a surface-tension-reducing component intended to improve penetration into lesion crevices and irregularities while limiting uncontrolled spreading onto surrounding skin.

The independent composition claim requires:

A topical composition for treating a skin condition;
Approximately 25%-70% w/w hydrogen peroxide; and
Approximately 1%-5% w/w 2-propanol.

The claim uses “comprising,” which generally permits additional ingredients. A formulation containing the claimed hydrogen peroxide and 2-propanol ranges could therefore remain within claim 1 despite including water, stabilizers, gelling agents, buffers, preservatives, or other excipients.

How broad is claim 1 of US 9,675,639?

Claim 1 is commercially significant because it does not require a particular skin disease, formulation viscosity, pH, surface tension, applicator, or stabilizer. It is a composition claim with a broad concentration window.

Hydrogen peroxide range

The claim covers approximately 25%-70% w/w hydrogen peroxide. The dependent claims create narrower ranges around the commercially relevant concentrations:

Claim	Hydrogen peroxide limitation
1	About 25%-70%
2	Selected concentrations including 25%, 32.5%, 40%, 45%, 50%, and 70%
20	About 30%-50%
21	About 35%-50%
22	About 40%-50%
23	About 35%-45%
24	About 40%-45%
25	About 40%
26	About 45%

The claim structure captures both broad concentration ranges and specific point concentrations. This creates overlapping fallback positions if a court narrows the broad range or finds one concentration range insufficiently supported.

2-propanol range

Claim 1 covers approximately 1%-5% w/w 2-propanol. Claims 27-37 subdivide the range into narrower intervals and specific concentrations from 1.5% through 4.5%.

The commercially important endpoints are:

1% 2-propanol under claim 3;
2%-5% under claim 27;
3%-5% under claim 28;
4%-5% under claim 29;
4.5%-5% under claim 30; and
5% in the formulation claims directed to 40% or 45% hydrogen peroxide.

A product containing 40% hydrogen peroxide and 5% 2-propanol is directly addressed by claims 38, 40, 42, 45, 47, and 49. A product containing 45% hydrogen peroxide and 5% 2-propanol is directly addressed by claims 39, 41, 43, 46, 48, and 50.

What formulations are protected by US 9,675,639?

The patent protects both open and closed formulation configurations.

Open “comprising” formulations

Claims 1-43 use “comprising” language. These claims can cover formulations containing additional components, including:

Water;
Stabilized hydrogen peroxide;
Stannate;
Sodium pyrophosphate;
Organophosphonates;
Nitrates;
Phosphoric acid;
Colloidal silicates;
Polycarbophil;
Polyvinylpyrrolidone;
Poloxamers;
Bentonite;
Cross-linked acrylic polymers;
Silicates;
Hyaluronic acid; and
Cross-linked hyaluronic acid.

The dependent claims do not require every listed stabilizer or gelling agent. They identify alternative embodiments.

“Consisting of” formulations

Claims 44-50 use “consisting of,” which is narrower than “comprising.” These claims are directed to a formulation consisting of:

Approximately 25%-70% stabilized hydrogen peroxide;
2-propanol in the stated range; and
An excipient.

Claims 47-50 identify water as the excipient for the 40% and 45% embodiments.

The closed language creates a potential design-around route for a formulation requiring an additional non-excipient active ingredient or a component that materially changes the claimed composition. That route does not necessarily avoid claims 1-43, which use open language.

What are the strongest commercial claims?

The strongest commercial claims are the claims that map directly to the formulation used for ESKATA, the 40% hydrogen peroxide product approved for seborrheic keratosis.

Claim cluster	Commercial relevance
Claims 1-3	Broad hydrogen peroxide and 2-propanol composition
Claims 13-16	Specific stabilized hydrogen peroxide formulations with 5% 2-propanol and surface-tension limits
Claims 24-26	40%-45% hydrogen peroxide ranges and point concentrations
Claims 38-43	40% or 45% hydrogen peroxide with 5% 2-propanol and water
Claims 51-54	Treatment methods for skin conditions, including warts, molluscum, acrochordons, and seborrheic keratosis
Claims 67-68	Seborrheic keratosis treated with approximately 40% hydrogen peroxide and 5% 2-propanol
Claims 69-70	Wart treatment using approximately 45% hydrogen peroxide and 5% 2-propanol

Claims 67-70 are narrower than claim 51 but commercially important because they connect the formulation to specific treatment indications.

How do the surface-tension and performance claims affect infringement?

Claims 9-12 and 17-19 add measurable product-performance limitations.

Claim	Limitation
9	Surface tension of approximately 42-55 mN/m at 37°C
10	2-propanol reduces surface tension to increase penetration
11	2-propanol reduces surface tension while minimizing spread
12	Stability for specified periods at 5°C, 30°C, or 40°C
17	Mean steady-state hydrogen peroxide release of approximately 1,000-1,750 µg/cm²/hour
18	Mean redox potential of approximately 415-430 mV
19	pH of approximately 3.5-4

These limitations create evidentiary issues in an infringement dispute. A patentee would typically need product testing under defined methods and conditions. Surface tension, release rate, redox potential, pH, and storage stability can vary with temperature, sampling procedure, container closure, manufacturing age, and batch composition.

The limitations also create design-around opportunities. A competing product could seek to retain the hydrogen peroxide and 2-propanol concentrations while falling outside the claimed surface-tension, redox-potential, pH, or release-rate ranges. That approach would not avoid claim 1 or other claims lacking the performance limitation.

What skin conditions and treatment methods are covered?

Claim 51 broadly covers topical administration for a skin condition. Claim 53 lists a very large group of conditions, including:

Warts and recurrent or recalcitrant warts;
Molluscum contagiosum;
Seborrheic keratosis;
Acrochordons and fibroepithelial polyps;
Actinic keratosis;
Keratinizing and epithelial lesions;
Benign tumors and adnexal tumors;
Pigmented lesions;
Vascular lesions;
Fungal infections and onychomycosis;
Psoriasis, rosacea, acne, and hyperpigmentation; and
Certain malignant or premalignant lesions.

Claim 54 narrows the list to warts, molluscum contagiosum, acrochordons, seborrheic keratosis, and condyloma acuminata. Claims 67-70 focus on seborrheic keratosis and warts.

The breadth of claim 53 may create validity pressure under written-description and enablement doctrines. The claim covers a wide range of biologically distinct conditions, including infections, benign tumors, malignant lesions, pigmentary disorders, and inflammatory diseases. A challenger could argue that the specification does not adequately demonstrate possession of, or enable treatment across, the full disease list. Claims directed to the disclosed commercial formulations and seborrheic keratosis treatment are likely to present a narrower validity target.

What applicator technology is protected?

Claims 62-66 do not claim the applicator as a standalone apparatus. They claim methods of administering the composition using an applicator having:

A frangible ampoule containing the composition;
An applicator body;
An applicator hub;
A tip;
A filter between the ampoule and tip; and
A pressure-sensitive rupture mechanism.

The claims also cover controlling flow by varying squeezing force and contacting the tip directly with a targeted lesion.

This structure is commercially relevant because high-concentration hydrogen peroxide requires controlled, localized delivery. A competing product using a conventional bottle, pump, dropper, brush, or prefilled syringe may avoid claims 62-66 while remaining exposed to the composition and treatment-method claims.

When does US Patent 9,675,639 lose exclusivity?

The patent issued in 2017 and traces priority to March 15, 2013. The expected base patent-term endpoint is approximately March 2034, calculated from the nonprovisional filing date, subject to any patent-term adjustment. The legally operative date should be confirmed through USPTO Patent Center and the patent’s front page because patent-term adjustment, terminal disclaimers, and maintenance-fee events can change the effective expiration date. [1, 2]

The patent term is separate from FDA regulatory exclusivity. ESKATA received FDA approval in December 2017 under NDA 209305 for raised seborrheic keratoses in adults. FDA approval did not extend the patent term. [3]

The product was later discontinued commercially, and FDA’s Orange Book reflects the regulatory status of the NDA rather than a continuing commercial obligation to market the product. Regulatory discontinuation does not, by itself, cancel an issued patent.

What is the Orange Book status of ESKATA and the patent?

ESKATA is the trade name associated with topical hydrogen peroxide 40% for raised seborrheic keratosis. FDA approved the product in December 2017. [3]

The Orange Book analysis should distinguish four issues:

Whether NDA 209305 remains listed;
Whether the product is identified as discontinued;
Whether US 9,675,639 is listed against the NDA;
Whether any patent listing remains relevant to an abbreviated new drug application.

A patent can remain legally enforceable after a product is discontinued. Conversely, a patent’s presence in the Orange Book does not establish validity or guarantee that a product-specific patent would block every alternative hydrogen peroxide formulation.

For a generic applicant, the relevant regulatory route would depend on whether FDA treats the proposed product as pharmaceutically equivalent and therapeutically equivalent to the reference product. A materially different high-concentration topical formulation could face a different regulatory pathway, including potential requirements for a 505(b)(2) application rather than a conventional ANDA.

Have companies filed Paragraph IV challenges?

No widely reported Paragraph IV litigation directed specifically to US 9,675,639 is identified in the principal public sources associated with ESKATA and the patent record. The absence of reported Paragraph IV litigation is commercially understandable because ESKATA was withdrawn from the market and the product opportunity was limited.

A Paragraph IV challenge would need to address both patent validity and the applicant’s proposed product. Likely challenge theories would include:

Anticipation by earlier hydrogen peroxide topical formulations;
Obviousness based on combining high-strength hydrogen peroxide with alcohol or a wetting agent;
Lack of written description for the broad skin-condition claims;
Enablement concerns for the extensive disease list;
Indefiniteness concerning “about,” “sufficient,” “effectively increases,” and “minimizing spread”;
Lack of novelty for specific 40% or 45% formulations; and
Noninfringement through a product outside the 2-propanol or hydrogen peroxide ranges.

The patent’s strongest defensive position is likely the combination of concentration ranges, stabilized hydrogen peroxide, 2-propanol, surface-tension behavior, and commercial lesion-treatment data. Its weaker positions are likely the broad disease claims and functional language that lacks a precise numerical boundary.

What prior-art and competing patent categories matter?

The relevant landscape extends beyond patents naming ESKATA. A freedom-to-operate review should include at least five categories.

Hydrogen peroxide dermatology patents

Earlier patents and publications have described hydrogen peroxide as an antimicrobial, oxidizing, keratolytic, or lesion-destroying agent. These references may be relevant to claims 1 and 51, particularly if they disclose concentrations within the claimed range.

Alcohol-containing topical formulations

Isopropanol and other alcohols are known as solvents, antiseptics, penetration enhancers, and wetting agents. A combination of hydrogen peroxide and alcohol may therefore present an obviousness issue unless the patent demonstrates an unexpected surface-tension, penetration, stability, or safety result.

Stabilized hydrogen peroxide

Hydrogen peroxide stabilization is established formulation technology. Claims 4-6 may be vulnerable to references disclosing stannates, phosphates, organophosphonates, nitrates, or related stabilizer systems in concentrated peroxide formulations.

Gel and viscosity systems

The gelling agents in claim 8 are conventional pharmaceutical and cosmetic excipients. Their inclusion may narrow infringement but does not necessarily provide a strong inventive-step distinction unless the specification ties a particular polymer or gel structure to an unexpected result.

Lesion applicators

Frangible ampoule applicators, filtered tips, and controlled-flow devices are separately patentable technology fields. The applicator claims should be searched independently from the formulation claims because a later product could avoid the formulation patent while raising risk under an applicator patent owned by another party.

How does the patent compare with the commercial ESKATA product?

Attribute	Patent claims	ESKATA commercial profile
Active ingredient	Approximately 25%-70% hydrogen peroxide	40% hydrogen peroxide
2-propanol	Approximately 1%-5%	Claimed patent embodiment of 5%
Indication	Broad list of skin conditions	Raised seborrheic keratoses
Dosage form	Solution or gel	Topical solution
Surface tension	Claims 9-11 and 13-16	Relevant to claimed formulation embodiments
pH	Approximately 3.5-4 in claim 19	Product-specific testing required
Applicator	Claims 62-66	Single-use controlled topical application technology
FDA status	Patent rights	FDA-approved in 2017; subsequently discontinued

The commercial product appears to occupy the center of the patent’s claim architecture: approximately 40% hydrogen peroxide, approximately 5% 2-propanol, water or other excipient, and localized application to seborrheic keratosis.

What generic launch risks exist?

A generic or follow-on manufacturer would face three principal risks.

First, a formulation containing 40% hydrogen peroxide and 5% 2-propanol would have a high literal-infringement risk under multiple claims through the expected patent term.

Second, changing the 2-propanol concentration below 1% or above 5% could avoid claim 1, but may alter wetting, penetration, tolerability, and clinical performance. Changing the hydrogen peroxide concentration outside 25%-70% could create a similar tradeoff.

Third, a formulation that avoids the composition claims could still face method-of-use risk if it uses a covered concentration for a claimed condition, especially seborrheic keratosis or warts.

A product with no 2-propanol would be outside the literal scope of claim 1, assuming no equivalent formulation theory applies. A product using ethanol, isopropyl alternatives, surfactants, or silicone-based wetting agents would require separate analysis under the doctrine of equivalents and against other patents.

How strong is the patent estate?

US 9,675,639 is strongest as a formulation patent directed to the 40% or 45% hydrogen peroxide and 5% 2-propanol combinations. Its strength comes from claim redundancy: several independent or semi-independent claim paths cover the same commercial concentration pair.

Its principal weaknesses are:

Extensive reliance on conventional ingredients;
Broad disease coverage in claim 53;
Functional terms such as “sufficient,” “effectively increases,” and “minimizing spread”;
Potential prior art involving concentrated hydrogen peroxide, alcohols, stabilizers, and topical lesion treatment;
Potential enablement issues for the full range of listed conditions; and
Dependence on measurable product attributes that may vary by test protocol.

The patent is therefore commercially meaningful but not uniformly strong across all 70 claims. The formulation claims directed to the marketed concentration pair are more important than the broad disease and generalized treatment claims.

Key Takeaways

US 9,675,639 covers topical formulations containing approximately 25%-70% hydrogen peroxide and 1%-5% 2-propanol.
The principal commercial embodiments are 40% or 45% hydrogen peroxide with 5% 2-propanol.
Claims 1-50 cover compositions; claims 51-70 cover treatment methods and specialized applicator use.
Claim 1 is broad because it uses “comprising” and does not require a specific disease, pH, gel, stabilizer, or applicator.
Claims 13-19 add surface tension, release, redox potential, pH, and stability limitations.
Claims 67-70 directly target seborrheic keratosis and wart treatment.
The expected base patent expiration is approximately March 2034, subject to USPTO patent-term adjustments and related status events.
No widely reported Paragraph IV litigation directed specifically to this patent is identified in the principal public record.
The most credible design-around strategies involve removing 2-propanol, moving outside the 25%-70% hydrogen peroxide range, or using a different delivery and treatment configuration.
The broadest disease claims present greater written-description and enablement exposure than the narrower commercial formulation claims.

Frequently Asked Questions

Does US 9,675,639 cover ordinary 3% hydrogen peroxide?

No. The independent claims require approximately 25%-70% w/w hydrogen peroxide. Ordinary 3% topical hydrogen peroxide is outside that concentration range.

Does a 40% hydrogen peroxide product infringe without 2-propanol?

It would not literally satisfy claim 1 if it contains no 2-propanol. The product would still require review against other patents, potential equivalents theories, and any later continuation patents.

Is a 5% isopropanol formulation covered?

Yes, “2-propanol” is the chemical name for isopropanol. A formulation containing approximately 1%-5% w/w 2-propanol falls within the central concentration limitation if it also contains approximately 25%-70% hydrogen peroxide.

Are claims 62-66 apparatus claims?

No. They are method claims that require use of an applicator with the specified frangible ampoule, body, hub, tip, and filter arrangement.

Can a company launch a hydrogen peroxide product after ESKATA discontinuation?

Commercial discontinuation does not eliminate patent risk. A launch analysis must address the patent’s remaining term, Orange Book and NDA status, formulation composition, indication, delivery method, and any continuation or related patents.

References

United States Patent No. 9,675,639 B2. (2017). Topical compositions and methods of use thereof. United States Patent and Trademark Office. https://patents.google.com/patent/US9675639B2/en
United States Patent and Trademark Office. (n.d.). Patent Center. https://patentcenter.uspto.gov/
U.S. Food and Drug Administration. (2017). FDA approves ESKATA for treatment of seborrheic keratoses. https://www.fda.gov/
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term information. https://www.uspto.gov/patents/laws/patent-term-adjustment-patent-term-extension-recovery-act-of-1999

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Aclaris	ESKATA	hydrogen peroxide	SOLUTION;TOPICAL	209305-001	Dec 14, 2017		DISCN	Yes	No	9,675,639	⤷ Start Trial	Y			TREATMENT OF SEBORRHEIC KERATOSES THAT ARE RAISED	⤷ 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	2015249841	⤷ Start Trial
Brazil	112016024630	⤷ Start Trial
Canada	2946568	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,675,639

Which drugs does patent 9,675,639 protect, and when does it expire?

Summary for Patent: 9,675,639