US Patent 10,426,787: Claims, Scope, Expiration, Orange Book Status, and Duobrii Patent Landscape

US Patent No. 10,426,787 protects a psoriasis-treatment method using a fixed topical combination of halobetasol propionate and tazarotene at the same concentrations used in Duobrii lotion: 0.01% and 0.045%, respectively. The patent is directed to the clinical use of the combination, not merely to the active ingredients individually. Its claim scope also reaches the specified emulsion vehicle, oil phase, carbomer system, once-daily eight-week regimen, and continued benefit after treatment ends.

The patent is commercially relevant to generic applicants seeking approval for a halobetasol propionate/tazarotene product. A product that uses the claimed concentrations and materially satisfies the claimed psoriasis-treatment conditions may face infringement exposure even if it uses a different trade name or makes minor formulation changes.

What does US Patent 10,426,787 cover?

The patent’s independent claim covers a method with six central elements:

Claim element	Requirement
Disease	Psoriasis
Administration	Topical application to an affected body area
Halobetasol propionate	0.01% by weight
Tazarotene	0.045% by weight
Vehicle	Aqueous dermatologically acceptable carrier
Functional result	Synergistic efficacy and synergistic reduction of itching, burning, or stinging

The claim also requires the carrier to contain:

Carbomer copolymer type B
Carbomer homopolymer type A
A liquid oil
Diethyl sebacate
Light mineral oil

The patent therefore combines composition limitations with method-of-treatment limitations. A generic formulation that contains the two active ingredients at the claimed concentrations is not automatically within the claim. It must also be evaluated against the carrier, dosage-form, administration, and functional limitations.

The claim language is directed to a fixed-dose topical combination, rather than concurrent use of separate halobetasol and tazarotene products.

How broad is claim 1 of US Patent 10,426,787?

Claim 1 is broad in dosage-form presentation but narrow in chemical composition and concentration.

It does not expressly require that the product be a lotion. The dependent claims identify an oil-in-water emulsion, lotion, and cream. Claim 1 can therefore potentially reach other topical presentations if they contain the required aqueous carrier and listed excipients.

The claim is narrow in four important respects:

The halobetasol propionate concentration must be 0.01% by weight.
The tazarotene concentration must be 0.045% by weight.
The carrier must include the specified carbomer and oil components.
The treatment must provide the claimed synergistic efficacy and reduction in at least one specified adverse event.

The functional language is material. The claim does not merely require that the formulation contain both actives. It requires that the combination be capable of providing synergistic efficacy and synergistic reduction of itching, burning, or stinging.

That limitation can create both enforcement value and litigation complexity. A patent owner may argue that the required synergy is demonstrated by clinical or experimental evidence. A challenger may argue that the limitation is indefinite, unsupported, not enabled across the full claim scope, or absent from a proposed generic product’s actual use.

What do claims 2 through 7 add?

The dependent claims narrow the method in different ways.

Claim	Added limitation	Practical effect
2	Application once daily for eight weeks	Aligns the claim with the principal clinical regimen
3	Composition is an oil-in-water emulsion	Narrows the vehicle architecture
4	Actives are dissolved in a component of the liquid oil	Targets the active-loading method and oil phase
5	Emulsion is a lotion	Closely tracks the commercial dosage form
6	Emulsion is a cream	Extends protection beyond lotion presentation
7	Relief continues for four weeks after eight weeks of application	Adds a post-treatment durability limitation

Claim 5 is particularly relevant to Duobrii because the approved product is a lotion. Claim 4 may create a formulation-specific barrier where the active ingredients are dissolved in the oil phase rather than dispersed separately or incorporated into another phase.

Claim 7 is narrower and more difficult to establish because it requires continued relief for four weeks after the eight-week treatment period. The claim may be relevant to clinical evidence and labeling, but infringement analysis would depend on whether the generic product is directed to, used for, or capable of producing the claimed post-treatment result under the relevant patent-law standards.

What formulation is protected by US Patent 10,426,787?

The formulation protected by the patent is a topical aqueous system containing:

0.01% halobetasol propionate
0.045% tazarotene
Carbomer copolymer type B
Carbomer homopolymer type A
Diethyl sebacate
Light mineral oil

Claims 3 through 6 further identify an oil-in-water emulsion, with the product capable of being a lotion or cream. Claim 4 requires dissolution of halobetasol propionate and tazarotene in a component of the liquid-oil phase.

This formulation structure is significant because a competitor could attempt to design around the patent through a different vehicle. Possible design-around strategies could include:

Changing one or both active concentrations
Using a different oil system
Omitting one of the specified carbomer types
Using a water-in-oil emulsion
Using a gel, foam, ointment, spray, or nonemulsion vehicle
Keeping the actives in separate phases
Using a different topical dosage form with a different excipient system

Each approach carries technical and regulatory constraints. A formulation change that avoids literal infringement may still produce an equivalent product, and a change to the active concentrations or vehicle may require separate pharmaceutical development and regulatory justification.

When does US Patent 10,426,787 expire?

US Patent 10,426,787 issued on October 1, 2019. Its term is tied to the relevant nonprovisional patent family and is expected to extend into 2034, subject to the official patent-term calculation, any patent-term adjustment, and terminal-disclaimer issues recorded by the USPTO.

For commercial planning, the relevant date is the patent expiration date appearing in the USPTO and FDA records for the patent family. Patent expiration should not be inferred solely from the issue date. The applicable date can reflect:

The earliest effective nonprovisional filing date
Patent-term adjustment
Patent-term extension
Terminal disclaimer
Continuation or divisional relationships

The Duobrii patent family has been associated with protection extending to approximately 2034. The FDA Orange Book remains the controlling commercial reference for listed patents and their reported expiration information. [1][2]

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

Duobrii is an FDA-approved topical prescription product containing halobetasol propionate 0.01% and tazarotene 0.045% for the topical treatment of plaque psoriasis in adults. The product was approved in 2019 under NDA 210336. [3]

The FDA Orange Book is relevant because it identifies patents submitted by the NDA holder for the approved drug and provides the patent information used in abbreviated new drug application certification procedures. A patent may be relevant to a product’s commercial exclusivity even when the patent claim is narrower than the complete approved product.

For this patent, the key regulatory questions are:

Is US 10,426,787 listed for the approved Duobrii product?
What use code or product information accompanies the listing?
Is the patent listed against the drug product, an approved method of use, or both?
Has the listing been removed, corrected, or superseded?
Are later patents listed for the same product or formulation?

FDA listing status can change through corrections, delistings, new patent submissions, or administrative updates. An Orange Book listing does not establish validity or infringement. It does, however, affect the filing and litigation consequences of an ANDA Paragraph IV certification. [1]

How do Paragraph IV challenges apply to this patent?

A generic applicant seeking approval for a halobetasol propionate/tazarotene product may certify under Paragraph IV that an Orange Book-listed patent is invalid, unenforceable, or will not be infringed by the proposed product. Under the Hatch-Waxman framework, the certification can trigger patent litigation if the NDA holder or patent owner sues within the statutory period. [4]

For US 10,426,787, a Paragraph IV strategy could focus on:

Lack of novelty
Obviousness of combining halobetasol propionate and tazarotene
Obviousness of the claimed concentrations
Written-description support for the synergy limitations
Enablement across the claimed formulation range
Indefiniteness of “synergistic efficacy” or “synergistic reduction”
Noninfringement based on the generic carrier or dosage form
Failure to satisfy the claimed post-treatment benefit in claim 7
Improper patent listing or an inapplicable use code

The concentration limitations may make anticipation more difficult if no single prior-art reference discloses the exact combination and carrier. Obviousness remains the central validity risk because both active ingredients were known topical dermatologic agents, and combination therapy may be challenged as an expected treatment strategy.

The functional synergy language may provide patent-owner leverage if supported by clinical data. It may also provide a challenger with a validity and claim-construction target.

Which companies are likely to challenge the Duobrii patent estate?

The principal competitive threat is from ANDA applicants seeking approval for a generic fixed-dose halobetasol propionate/tazarotene product. Public commercial risk depends on whether an applicant has filed an ANDA, submitted a Paragraph IV certification, or entered litigation.

A generic applicant may pursue one of three approaches:

Strategy	Regulatory objective	Patent exposure
Same strengths and similar lotion	Direct substitution for Duobrii	Highest exposure to formulation and method claims
Same actives with altered vehicle	Therapeutic alternative or design-around	Lower literal infringement risk, but formulation and use claims remain relevant
Separate products or sequential therapy	Avoid fixed-combination claims	May avoid composition claims but is less commercially substitutable

A biosimilar pathway is not relevant. Duobrii is a small-molecule topical drug, not a biologic. Competitive entry would proceed through the ANDA pathway or, for a materially different product, a separate NDA pathway. [4]

How strong is the patent estate for Duobrii?

US 10,426,787 is strongest against a directly substitutable product that reproduces the Duobrii formulation and regimen. Its practical strength is lower against a product that changes the vehicle, excipients, emulsion type, active concentrations, or labeling.

The patent’s strengths include:

Exact commercial active concentrations
Coverage of a topical psoriasis method
Formulation limitations tied to the product architecture
Dependent claims directed to lotion and cream forms
Claims directed to adverse-event reduction
A once-daily eight-week treatment regimen

Its vulnerabilities include:

A potentially crowded prior-art field for both active ingredients
Functional synergy limitations requiring technical proof
Possible disputes over whether the carrier contains the required carbomer types
Potential noninfringement through vehicle or excipient changes
Questions over inducement based on generic labeling
Narrowness of the four-week post-treatment-relief claim

The patent should be assessed as part of a family-level portfolio rather than in isolation. Other Duobrii patents may cover compositions, methods, formulations, manufacturing processes, or additional clinical characteristics. A generic applicant that defeats or avoids US 10,426,787 may still face other listed or unlisted patent claims.

What patent litigation and settlement issues affect generic entry?

Patent litigation risk depends on the Orange Book listing, the ANDA certification, and the patent owner’s response. A timely infringement suit can impose the statutory 30-month stay on FDA approval, subject to statutory exceptions and court action. [4]

A settlement agreement could establish:

A licensed entry date
A royalty or supply arrangement
Restrictions on formulation or indication
A launch date before patent expiration
A contingent entry date tied to litigation outcomes
A permitted authorized-generic arrangement

No settlement terms should be assumed without a public court filing, FTC review, SEC disclosure, or other authoritative record. The commercial impact of a settlement would depend on whether it permits an at-risk launch, a licensed launch before patent expiry, or entry only after the patent estate expires.

What generic launch scenarios exist for halobetasol/tazarotene?

Three scenarios are commercially plausible.

Scenario 1: Direct generic substitution

The applicant matches the 0.01%/0.045% strengths and uses a lotion or comparable oil-in-water emulsion. This approach has the strongest substitutability but the greatest exposure to US 10,426,787 and related patents.

Scenario 2: Formulation design-around

The applicant changes the oil system, carbomer system, emulsion structure, or active-loading method. This may reduce literal infringement risk but can create new development, bioequivalence, and manufacturing challenges.

Scenario 3: Delayed entry

The applicant accepts the patent position, resolves litigation through settlement, or waits for expiry. This reduces litigation risk but postpones market access and revenue capture.

Duobrii’s commercial exposure is concentrated in the period before the relevant patent family expires. Generic erosion would likely pressure price, pharmacy substitution, payer coverage, and branded promotion. The scale of revenue exposure depends on the product’s net sales, market share, payer restrictions, and the number of approved generic competitors.

What geographic coverage does US Patent 10,426,787 provide?

The patent provides protection in the United States only. It does not directly protect the product in Canada, Europe, Japan, China, or other jurisdictions.

International protection would require corresponding national or regional patents. The scope and expiration dates of those rights may differ because of:

Different claim amendments
National-phase prosecution
Patent-term rules
Supplementary protection certificates
Patent oppositions
Local validity decisions
Different regulatory exclusivity regimes

US patent protection is therefore only one component of the global Duobrii and halobetasol/tazarotene landscape.

Key Takeaways

US Patent 10,426,787 claims treatment of psoriasis with halobetasol propionate 0.01% and tazarotene 0.045%.
Claim 1 requires a specified aqueous carrier containing carbomer copolymer type B, carbomer homopolymer type A, diethyl sebacate, and light mineral oil.
Dependent claims cover once-daily eight-week treatment, oil-in-water emulsions, lotion and cream forms, oil-phase dissolution, and four weeks of post-treatment relief.
The patent is most relevant to a directly substitutable Duobrii generic.
The functional synergy limitations may strengthen the patent commercially while creating validity and claim-construction issues.
Duobrii is an FDA-approved small-molecule topical product, so biosimilar analysis is not applicable.
Generic entry would generally involve an ANDA and potentially a Paragraph IV certification.
The patent family is associated with protection extending into approximately 2034, subject to official term calculations and Orange Book records.
A complete freedom-to-operate analysis must consider the entire Duobrii patent family, not US 10,426,787 alone.

FAQs on US Patent 10,426,787 and Duobrii Exclusivity

Does US Patent 10,426,787 cover halobetasol propionate by itself?

No. The asserted combination requires halobetasol propionate together with tazarotene at the specified concentrations and within the claimed topical treatment framework.

Does the patent cover a tazarotene-only psoriasis product?

No. A tazarotene-only product would not satisfy the fixed-combination limitation in claim 1.

Can a generic avoid the patent by changing the lotion to a cream?

Not necessarily. Claim 6 expressly covers a cream, and other claims may apply depending on the composition, carrier, and method of use.

Is a four-week post-treatment benefit required for every patent claim?

No. The four-week continuation-of-relief limitation appears in claim 7. It is not required by claims 1 through 6.

Is US 10,426,787 a composition patent or a method-of-use patent?

Its principal protection is method-of-use protection. The claims require treating psoriasis by applying a composition with specified active ingredients, concentrations, carrier components, and clinical characteristics.

References

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. (2019). U.S. Patent No. 10,426,787.
U.S. Food and Drug Administration. (2019). Duobrii prescribing information.
Food and Drug Administration. (2024). Abbreviated new drug application submissions: ANDAs, patent certifications, and the 30-month stay. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Bausch	DUOBRII	halobetasol propionate; tazarotene	LOTION;TOPICAL	209354-001	Apr 25, 2019	AB	RX	Yes	Yes	10,426,787	⤷ Start Trial				TOPICAL TREATMENT OF PLAQUE PSORIASIS IN ADULTS	⤷ 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	2016279801	⤷ Start Trial
Brazil	112017027332	⤷ Start Trial
Brazil	112019023817	⤷ Start Trial
Canada	2988577	⤷ Start Trial
Canada	3063371	⤷ Start Trial
China	108282998	⤷ Start Trial
Cyprus	1123354	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,426,787

Which drugs does patent 10,426,787 protect, and when does it expire?

Summary for Patent: 10,426,787