Details for Patent: 9,119,781

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Which drugs does patent 9,119,781 protect, and when does it expire?

Patent 9,119,781 protects ENSTILAR and is included in one NDA.

Protection for ENSTILAR has been extended six months for pediatric studies, as indicated by the *PED designation in the table below.

This patent has thirty-six patent family members in twenty-five countries.

Summary for Patent: 9,119,781

Title:	Pharmaceutical spray composition comprising a vitamin D analogue and a corticosteroid
Abstract:	The present invention relates to a topical spray composition comprising a biologically active vitamin D derivative and a corticosteroid, and its use in the treatment of dermal diseases and conditions. The spray comprises especially a propellant selected from the group consisting of dimethyl ether, diethyl ether and methylethyl ether or a mixture thereof and further a pharmaceutically acceptable lipid carrier solubilised or suspended in said propellant.
Inventor(s):	Marianne Lind, Gritt Rasmussen, Mette Rydahl Sonne, Jens Hansen, Karsten Petersson
Assignee:	Leo Pharma AS
Application Number:	US13/703,214
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 9,119,781
Patent Claim Types: see list of patent claims	Use; Composition;

United States Patent 9,119,781: Claim Scope, Enstilar Coverage, Orange Book Status, and Generic Entry Risk

U.S. Patent No. 9,119,781 protects a narrow aerosol formulation combining calcipotriol, or calcipotriol monohydrate, with a betamethasone ester in a substantially anhydrous, propellant-based topical composition. The claims require dimethyl ether, optionally combined with C3-C5 alkanes, specific oily co-solvents, and a paraffin-based lipid carrier that forms an occlusive semi-solid layer after application.

The patent is directly aligned with the formulation architecture of Enstilar foam, which contains calcipotriene and betamethasone dipropionate. Its principal commercial relevance is formulation protection rather than protection of the active ingredients themselves. The patent does not cover every topical calcipotriol/betamethasone product, and a generic applicant would need to address each required limitation, including the propellant system, co-solvent, lipid carrier, and occlusive film.

What does U.S. Patent 9,119,781 protect?

The patent protects a sprayable, storage-stable topical composition with five required technical elements:

Claim element	Required scope
Active 1	Calcipotriol or calcipotriol monohydrate at approximately 0.00001% to 0.05% w/w
Active 2	A betamethasone ester at approximately 0.0005% to 1%
Propellant	Dimethyl ether, alone or with one or more C3-C5 alkanes
Oily co-solvent	One of the specified polyoxypropylene ether compounds at 0.1% to 10%
Lipid carrier	10% to 50% w/w of one or more paraffins, solubilized or suspended in the propellant

The formulation must also be substantially anhydrous and sprayable. After the propellant evaporates, the lipid carrier must form a semi-solid, occlusive layer on the skin.

The independent treatment claim, claim 9, extends the formulation protection into use of the composition for psoriasis, pustulosis palmoplantaris, ichthyosis, dermatitis, rosacea, or acne.

How do the individual claims narrow the patent scope?

Claim 1: Core formulation claim

Claim 1 is the central composition claim. It combines concentration ranges, physical characteristics, excipient identity, propellant identity, and post-application behavior.

A product may avoid literal infringement if it omits any required element. Potential distinctions include:

• Replacing dimethyl ether with a different propellant system.
• Using an oily co-solvent outside the listed polyoxypropylene ether group.
• Omitting a paraffin carrier.
• Using a non-occlusive vehicle.
• Producing an emulsion, gel, cream, lotion, or foam that does not satisfy the claimed sprayable composition.
• Using water in an amount inconsistent with the substantially anhydrous limitation.
• Falling outside the claimed active-ingredient concentration ranges.

The concentration limitations are important, but concentration alone is unlikely to define the commercial boundary. Enstilar’s labeled concentrations, 0.005% calcipotriene and 0.064% betamethasone dipropionate, fall within the claimed ranges [2].

Claims 2 and 10: Corticosteroid and alkane selection

Claim 2 identifies betamethasone dipropionate and betamethasone valerate as the relevant corticosteroid esters. Claim 10 identifies propane, isopropane, n-butane, and isobutane as qualifying alkanes.

The claims therefore reach the principal corticosteroid used in Enstilar, betamethasone dipropionate, and the hydrocarbon propellants commonly used with dimethyl ether in aerosol systems.

Claims 3, 4, and 12-15: Propellant ratios

These claims narrow the hydrocarbon-to-dimethyl-ether ratio:

Claim	Ratio limitation
Claim 4	6:1 to 0:1 v/v
Claim 12	5:1 to 1:2 v/v
Claim 13	4:1 to 1:1 v/v
Claim 14	4:2 to 1:1 v/v
Claim 15	4:2 to 4:3 v/v

Claims 12 through 15 create progressively narrower ratio positions. A competitor using the same actives, co-solvent, and paraffin carrier may still avoid these dependent claims if its propellant ratio falls outside the applicable range. That strategy would not necessarily avoid claim 1, which does not impose a specific hydrocarbon-to-dimethyl-ether ratio.

Claims 5-7 and 16-17: Concentration subranges

These claims narrow the quantities of the principal excipients:

• Claim 5: lipid carrier at 3% to 45% w/w.
• Claim 6: propellant at 55% to 70% w/w.
• Claim 7: oily co-solvent at 0.5% to 3% w/w.
• Claim 16: oily co-solvent at 1% to 2.5% w/w.
• Claim 17: oily co-solvent at 1.5% to 2% w/w.

Claims 16 and 17 are commercially significant because they focus on a relatively tight co-solvent range likely to correspond to an optimized formulation rather than a broad research space.

Claims 8 and 11: Paraffin and viscosity architecture

Claim 8 specifies paraffin hydrocarbons with chain lengths from C5 to C60, with peaks at defined chain-length intervals, including C14-C16, C18-C22, C20-C22, C20-C26, C28-C40, and C40-C44.

Claim 11 adds a lipophilic viscosity-increasing agent selected from:

• Microcrystalline wax;
• Silicone wax;
• Hydrogenated castor oil; or
• Mixtures of those materials;

together with an isoparaffin.

These limitations target the physical behavior of the residual film. They are not merely excipient lists. The claim requires a carrier capable of forming a semi-solid and occlusive layer after the propellant evaporates. A design-around analysis would therefore need formulation and product-performance data, not only a comparison of ingredient names.

Is U.S. Patent 9,119,781 directed to Enstilar?

Yes. The claim structure corresponds closely to Enstilar aerosol foam, marketed by LEO Pharma for plaque psoriasis. Enstilar contains calcipotriene, also referred to as calcipotriol, and betamethasone dipropionate in a topical aerosol formulation [2].

The product label identifies the active ingredients as:

Enstilar component	Labeled concentration
Calcipotriene	0.005%
Betamethasone dipropionate	0.064%

The label also identifies a vehicle system that includes white petrolatum, mineral oil, polyoxypropylene-15-stearyl ether, butane, and dimethyl ether [2]. Those ingredients map directly onto the principal elements recited in claim 1.

The patent does not, however, claim the chemical compounds calcipotriol or betamethasone dipropionate in isolation. Nor does it necessarily block every cream, ointment, suspension, lotion, or non-aerosol foam containing the same active ingredients.

What is the Orange Book status of U.S. Patent 9,119,781?

U.S. Patent 9,119,781 has been listed in connection with FDA-approved calcipotriene and betamethasone dipropionate aerosol foam products, including Enstilar, according to FDA patent-listing materials and product-specific Orange Book records [3].

The patent issued on September 1, 2015. Its term is tied to the relevant U.S. application and priority chain. A standard 20-year term calculation places expiration in 2028, subject to the official patent-term adjustment reflected in USPTO records [1]. The patent was not expired as of the 2025 period covered by this analysis.

Event	Date or status
Earliest reported priority	August 21, 2007
U.S. patent issuance	September 1, 2015
Patent number	9,119,781
Patent type	Formulation and method-of-treatment claims
Commercial product association	Enstilar aerosol foam
Expected statutory term	2028, subject to official term adjustment
Orange Book relevance	Listed formulation patent for the approved aerosol product

A definitive Orange Book conclusion requires checking the current FDA electronic Orange Book and the latest patent-listing update because FDA listings and approved-product associations can change over time [3].

When does Enstilar lose exclusivity?

Enstilar’s exclusivity has several components:

1. Patent protection for the formulation.
2. FDA regulatory exclusivity associated with the approved product.
3. Additional patents or patent-family members that may cover related formulations, delivery systems, or methods.
4. Regulatory requirements imposed on an ANDA applicant seeking approval.

The principal FDA approval date for Enstilar was October 16, 2015 [2]. The product is a small-molecule drug, so its generic pathway is an abbreviated new drug application rather than a biosimilar application.

The 9,119,781 patent is more commercially important than the active-ingredient patents because calcipotriene and betamethasone dipropionate are established molecules. The remaining barrier is the combination of aerosol delivery, anhydrous stability, excipient selection, and residual occlusive film performance.

How strong is the patent estate for Enstilar?

The 9,119,781 patent has moderate-to-strong formulation value but a narrower legal perimeter than a composition-of-matter patent.

Strengths

• It covers both active ingredients in the same dosage form.
• It recites the specific propellant architecture used by the commercial product.
• It includes a broad independent claim covering several alkanes and a broad active-ingredient range.
• It has dependent claims directed to practical commercial ranges.
• It covers both composition and treatment use.
• The physical requirement for a semi-solid, occlusive layer can support infringement arguments based on product performance, not only ingredient identity.

Weaknesses

• The patent does not claim calcipotriol or betamethasone dipropionate as standalone compounds.
• The independent claim contains numerous limitations.
• The claim requires one of a defined set of oily co-solvents.
• The claim requires a paraffin-based lipid carrier.
• A competing topical product using a different delivery system may avoid literal infringement.
• Some claim terms, including “substantially anhydrous,” “storage stable,” “sprayable,” and “occlusive layer,” could create claim-construction and proof issues.

The patent is strongest against an aerosol product that copies the Enstilar formulation architecture. It is weaker against conventional creams, ointments, gels, lotions, aqueous suspensions, or aerosol products using a materially different vehicle.

What generic entry risks exist?

ANDA and Paragraph IV risk

A generic applicant seeking approval for a product equivalent to Enstilar could file an ANDA with one of the following certifications:

• Paragraph III certification, accepting delayed approval until patent expiry;
• Paragraph IV certification, asserting that the listed patent is invalid, unenforceable, or not infringed; or
• A section viii statement, where the applicant omits a patented method of use that is not necessary for its proposed labeling.

For a direct aerosol equivalent, a Paragraph IV challenge would likely focus on:

• Anticipation by earlier topical aerosol formulations;
• Obviousness based on known calcipotriene/betamethasone combinations and aerosol vehicles;
• Lack of written description or enablement for the full scope;
• Indefiniteness of functional and physical limitations;
• Non-infringement based on the selected co-solvent, carrier, propellant, or residual film;
• Patent-term or listing issues.

A generic applicant that uses the same active ingredients but changes the delivery system may have a stronger non-infringement position. The regulatory pathway becomes more difficult if the product is no longer pharmaceutically equivalent to the reference listed drug.

Litigation and 30-month stay

A proper Paragraph IV analysis requires the actual ANDA notice letter and any resulting complaint. Those documents determine which claims are challenged and whether the NDA holder filed within the statutory 45-day period. A timely patent-infringement action can trigger the statutory approval stay under the Hatch-Waxman framework, generally up to 30 months, subject to court actions and statutory exceptions [4].

No litigation conclusion should be drawn solely from the existence of a Paragraph IV certification. The operative issues are the asserted claims, the filing date, the litigation docket, and any settlement or consent judgment.

Is there biosimilar risk for Enstilar?

No conventional biosimilar risk applies. Enstilar contains chemically synthesized small-molecule active ingredients, not a biological product. A competing applicant would use the ANDA pathway, not the Public Health Service Act biosimilar pathway.

The principal competitive risks are:

• An authorized generic;
• An ANDA aerosol equivalent;
• A non-equivalent topical product;
• A compounded product;
• A product using the same active ingredients in a different dosage form;
• Substitution toward other calcipotriene or corticosteroid products.

Which competing products affect the patent landscape?

The relevant competitive set includes:

Product or category	Active ingredients	Delivery system	Relationship to 9,119,781
Enstilar	Calcipotriene and betamethasone dipropionate	Aerosol foam	Primary commercial product associated with the claims
Taclonex topical suspension	Calcipotriene and betamethasone dipropionate	Topical suspension	Different formulation architecture
Taclonex ointment	Calcipotriene and betamethasone dipropionate	Ointment	Different dosage form
Generic calcipotriene	Calcipotriene	Cream, ointment, or solution	Does not necessarily contain the claimed combination
Generic betamethasone dipropionate	Betamethasone dipropionate	Multiple topical forms	Does not necessarily contain the claimed combination
Other psoriasis foams	Various corticosteroids or vitamin D analogues	Aerosol foam	May compete clinically without practicing the claims

Older combination-product patents relating to calcipotriene and betamethasone may have expired or may protect different vehicles. The existence of those patents does not establish infringement of U.S. Patent 9,119,781.

What manufacturing and intellectual-property barriers remain?

The main manufacturing barriers are formulation reproducibility and aerosol performance. A competing manufacturer must control:

• Dissolution of both active ingredients in the propellant/co-solvent system;
• Water content;
• Canister and valve compatibility;
• Spray pattern and dose delivery;
• Sedimentation or phase separation;
• Long-term chemical stability;
• Paraffin particle or hydrocarbon distribution;
• Residual-film formation after propellant evaporation;
• Content uniformity across the container life.

These process controls may be protected by know-how even where a competitor designs around the patent claims. The patent itself does not necessarily claim every manufacturing step. A freedom-to-operate review should therefore separate:

1. Formulation patents;
2. Aerosol-container and valve patents;
3. Manufacturing-process patents;
4. Stability and packaging patents;
5. Method-of-use patents;
6. Regulatory exclusivity and Orange Book listings.

What generic launch scenarios are most plausible?

Direct aerosol equivalent

This is the highest litigation-risk scenario. A product with the same active concentrations, dimethyl ether/butane system, polyoxypropylene-15-stearyl ether, and paraffin carrier would closely approach the asserted claim set.

Reformulated aerosol

A competitor could alter the co-solvent, propellant, carrier, or residual-film system. This may reduce patent risk but could also prevent an ANDA from demonstrating pharmaceutical equivalence to Enstilar.

Non-aerosol combination product

A cream, ointment, gel, or suspension may avoid the aerosol claims. Its competitive position would depend on separate formulation patents and FDA approval requirements.

Authorized generic

An authorized generic supplied under agreement with the NDA holder could enter without resolving the same Paragraph IV issues faced by an independent ANDA applicant. No specific authorized-generic agreement is established by the patent claims alone.

Key Takeaways

• U.S. Patent 9,119,781 is a formulation patent centered on a calcipotriene/betamethasone aerosol system.
• Claim 1 requires a substantially anhydrous sprayable composition, dimethyl ether-based propellant, specified oily co-solvent, paraffin lipid carrier, and occlusive post-application layer.
• Claims 2 and 3-17 narrow the corticosteroid, alkane, propellant ratio, excipient, paraffin, and concentration ranges.
• The claims closely track the commercial architecture of Enstilar aerosol foam.
• The patent does not cover every calcipotriol/betamethasone topical product.
• A direct aerosol generic would face the highest Paragraph IV and infringement risk.
• A non-aerosol product or materially different propellant system may have a stronger design-around position.
• Enstilar is a small-molecule product, so biosimilar regulation is not applicable.
• Patent expiration should be determined from the official USPTO term-adjustment record and current FDA Orange Book listing, with the ordinary term calculation extending into 2028.
• Formulation know-how, aerosol manufacturing controls, and pharmaceutical-equivalence requirements may remain commercial barriers after patent expiry.

FAQs

Does U.S. Patent 9,119,781 cover calcipotriene cream?

No. The claims require a sprayable, substantially anhydrous propellant composition with specified excipients and a paraffin-based occlusive carrier. A conventional calcipotriene cream would not inherently satisfy those limitations.

Does changing betamethasone dipropionate to betamethasone valerate avoid the patent?

Not necessarily. Claim 2 expressly identifies betamethasone valerate as a covered betamethasone ester. Other corticosteroids may avoid the literal scope, but the full formulation must still be analyzed.

Can a product avoid the patent by removing dimethyl ether?

Removing dimethyl ether may avoid claim 1 because dimethyl ether is a required propellant component. The replacement product would still require separate analysis for other patents and FDA equivalence issues.

Does the patent cover a calcipotriene and betamethasone ointment?

The claimed composition is sprayable and propellant-based. A conventional ointment would generally fall outside the literal scope of these claims, subject to the details of its formulation and any other applicable patent.

Is a Paragraph IV challenge required for a generic Enstilar product?

A Paragraph IV certification is generally used when an ANDA applicant seeks approval before expiration of a listed patent and asserts that the patent is invalid, unenforceable, or not infringed. The certification strategy depends on the proposed product, labeling, patent listing, and approval timing.

References

1. United States Patent and Trademark Office. (2015). U.S. Patent No. 9,119,781, Pharmaceutical composition.
2. U.S. Food and Drug Administration. (2015). Enstilar: Prescribing information.
3. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Electronic Orange Book.
4. U.S. Food and Drug Administration. (2024). Abbreviated new drug application submissions: Patent certifications and notice requirements.

Drugs Protected by US Patent 9,119,781

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Leo Pharma As	ENSTILAR	betamethasone dipropionate; calcipotriene	AEROSOL, FOAM;TOPICAL	207589-001	Oct 16, 2015		RX	Yes	Yes					Y

Foreign Priority and PCT Information for Patent: 9,119,781

PCT Information
PCT Filed	June 10, 2011	PCT Application Number:	PCT/DK2011/000060
PCT Publication Date:	December 15, 2011	PCT Publication Number:	WO2011/154004

International Family Members for US Patent 9,119,781

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2011264198
Brazil	112012030653
Canada	2800181
China	102939078
Cyprus	1115991
Denmark	2579852