US Patent 9,566,286: Claim Scope, Exclusivity, Orange Book Status, and Generic Entry Risk

US Patent 9,566,286 protects a specific pressurized aerosol container for a substantially anhydrous calcipotriol-and-betamethasone topical composition. The patent is directed primarily to the integrated product package, not to calcipotriol, betamethasone, or the pharmaceutical composition standing alone. Its strongest coverage combines five elements: the active ingredients, a dimethyl-ether-based propellant system, a lipid carrier, a lined metal container, and specified valve and seal components.

The patent was assigned to LEO Pharma A/S and is associated with the Enstilar foam product, which contains calcipotriene and betamethasone dipropionate. The patent issued as US 9,566,286 B2 on February 7, 2017, from an application claiming priority to a March 16, 2012 filing. The ordinary 20-year patent term is expected to run to approximately March 15, 2033, before any patent-term adjustment or other statutory modification. [1]

What does US Patent 9,566,286 protect?

Claim 1 protects a pressurized dispensing container containing a narrowly defined topical aerosol composition. The claim requires every element below:

Claim element	Required scope
Product format	Pressurized container adapted to dispense a topical spray
Container	Metal container body
Active ingredients	Calcipotriol or calcipotriol monohydrate plus a betamethasone ester
Physical state	Sprayable, storage-stable, substantially anhydrous composition
Solvent or propellant	Dimethyl ether alone or dimethyl ether combined with a second propellant
Second propellant	C3-C5 alkanes, hydrofluoroalkanes, hydrochloroalkanes, fluoroalkanes, or chlorofluoroalkanes
Carrier	Pharmaceutically acceptable lipid carrier, solubilized or suspended in the propellant system
Dispensing system	Valve assembly and actuator releasing the composition as a spray
Container lining	Chemically inert polyimide-polyamide resin, polyamide, or polyimide coating

The claim uses “comprising” language. That generally permits additional ingredients, components, or structural elements, provided the accused product still contains all required claim limitations.

The patent therefore does not cover every calcipotriol/betamethasone formulation. It does not independently claim:

Calcipotriol as an active pharmaceutical ingredient;
Betamethasone dipropionate as a compound;
A topical composition without the claimed container;
A nonpressurized cream, ointment, gel, or lotion;
A pressurized product using a propellant outside the recited groups;
A container lacking the specified chemically inert lining.

How broad is independent claim 1?

Claim 1 is commercially important but structurally narrow. It is a combination claim that requires the drug composition and the package to be used together.

The claim has four principal limitations that may determine infringement:

The formulation must contain both calcipotriol or calcipotriol monohydrate and a betamethasone ester.
The formulation must be substantially anhydrous and storage stable.
The active ingredients must be dissolved in dimethyl ether or a permitted dimethyl-ether-containing propellant mixture.
The metal container must have a lining made from one of the recited polymer materials.

A generic manufacturer could potentially avoid literal infringement by changing one of these limitations. The most commercially practical design-around routes would involve a different container coating, a different propellant system, a nonmetal container, or a formulation that does not satisfy the claim’s “substantially anhydrous” or dissolved-active-ingredient requirements.

The “therapeutically effective amount” language is unlikely to narrow the claim to the exact Enstilar strength. It generally requires a clinically meaningful amount, not necessarily the marketed concentration. The “substantially anhydrous” limitation is more significant because it can create a factual dispute involving water content, manufacturing tolerances, storage conditions, and the meaning assigned to the term in the patent specification.

What do claims 2 through 19 add?

The dependent claims progressively narrow the container, valve, propellant, and material limitations.

Claims	Added limitation	Commercial significance
2	Dip tube and valve cup, valve body, and actuator	Covers a conventional dip-tube aerosol configuration
3	Stainless steel, tinplate, aluminum, aluminum alloy, or anodized aluminum	Defines permitted metal container materials
4	Aluminum or aluminum alloy	Narrows the container body to the likely commercial configuration
5	Polyimide-polyamide resin coating	Protects a specific internal lining choice
6-8	Chemically inert and propellant-impermeable gaskets or seals	Addresses compatibility and leakage control
8	Fluoroelastomer, FEP, FPM, or EPDM seals	Creates a materials-specific subcombination
9	Polyethylene or polypropylene dip tube	Narrows the dip-tube polymer
10	Crimped valve cup, valve stem, spring, and depressible actuator	Defines the mechanical valve structure
11	Valve-stem aperture of 0.05-1 mm	Controls liquid flow and spray characteristics
12	Actuator insert orifice of 0.3-1.5 mm	Controls spray discharge
13	Betamethasone dipropionate or betamethasone valerate	Narrows the corticosteroid ester
14-16	C3-C5 alkane, including propane, butane, or isobutane	Defines the second propellant
17-18	n-Butane/isobutane-to-dimethyl-ether ratio of 6:1 to 0:1 by volume	Covers propellant-ratio alternatives
19	Polyamide or acetal valve stem	Narrows valve-stem material

Claims 4, 5, 8, 11, 12, 17, and 19 are particularly relevant to a product-by-process comparison because they identify physical specifications that may be available through supplier records, component specifications, regulatory submissions, or discovery.

When does US Patent 9,566,286 lose exclusivity?

The expected ordinary expiration date is approximately March 15, 2033. The date reflects the 20-year term measured from the relevant US or international nonprovisional filing date, rather than the March 16, 2012 priority date. [1]

Milestone	Date
Earliest listed priority	March 16, 2012
US patent grant	February 7, 2017
Expected ordinary expiration	Approximately March 15, 2033
Product associated with patent	Enstilar topical foam
FDA approval of Enstilar	October 16, 2015

A final freedom-to-operate date should use the USPTO patent-term record and any terminal disclaimer or patent-term adjustment data. Patent expiration does not by itself remove FDA regulatory exclusivity, Orange Book listing effects, or separate patents covering the formulation or method of use.

What is the Orange Book status of US 9,566,286?

US 9,566,286 has been associated with the US regulatory protection for Enstilar, a topical aerosol foam containing calcipotriene and betamethasone dipropionate. The FDA-approved product is indicated for plaque psoriasis in patients 12 years of age and older. [2]

The patent’s regulatory significance depends on its listing status for the relevant Enstilar reference product and the use code assigned by FDA. An Orange Book-listed device or formulation patent can require an ANDA applicant to make a Paragraph IV certification if the applicant seeks approval before the listed patent expires. A listing does not establish infringement, validity, or enforceability. It establishes a regulatory certification and notice pathway.

The product is an approved small-molecule combination. It is not a biologic, and biosimilar approval under the Public Health Service Act is not the relevant competitive pathway. A competing manufacturer would generally pursue an ANDA if it can demonstrate pharmaceutical equivalence and bioequivalence, or a 505(b)(2) application if it relies on a listed drug while introducing material differences.

What Paragraph IV challenges could target this patent?

An ANDA applicant challenging an Orange Book-listed patent could assert that the patent is invalid, unenforceable, or not infringed. The principal technical and legal theories would likely concern:

Noninfringement

A proposed product could avoid claim 1 by using:

A nonmetallic canister;
An internal lining outside the polyimide, polyamide, or polyimide groups;
A propellant without dimethyl ether;
A formulation in which the active ingredients are not dissolved in the claimed propellant;
A composition containing materially more water;
A non-spray delivery format;
A valve or container arrangement lacking the claimed combination.

Dependent-claim exposure would require a separate element-by-element analysis. A product could avoid claims 11 and 12 by using different aperture or orifice dimensions while still potentially infringing claim 1.

Invalidity

Potential validity challenges could address:

Anticipation by earlier aerosol formulations;
Obviousness based on known calcipotriol/betamethasone compositions combined with known aerosol containers;
Indefiniteness of terms such as “substantially anhydrous,” “storage stable,” and “chemically inert”;
Written-description or enablement issues concerning the full range of propellants, coatings, seals, ratios, and device dimensions.

The combination of drug formulation and container technology may make an obviousness challenge fact intensive. The challenger would need to show not only that individual components were known, but also that a skilled person would have selected the claimed combination with a reasonable expectation of success.

What generic entry risks exist for Enstilar?

The main generic-entry risk is formulation-and-device replication rather than ordinary compound substitution. A generic entrant seeking a close Enstilar equivalent would likely need to evaluate:

Risk area	Effect on entry
Active ingredient combination	Limits substitution to products containing both calcipotriol and a betamethasone ester
Foam or spray delivery	Increases device and formulation development requirements
Anhydrous formulation	Requires control of water content and long-term stability
Dimethyl ether	Creates flammability, pressure, compatibility, and manufacturing constraints
Canister lining	May require a qualified alternative coating or a noninfringing package
Valve dimensions	Can affect spray performance, dose uniformity, and patient use
Seal materials	May affect leakage, extraction, adsorption, and propellant compatibility
ANDA equivalence	Requires matching dosage form, route, strength, and performance characteristics

A successful noninfringement position would not necessarily eliminate regulatory risk. FDA could still require comparative performance, stability, container-closure integrity, spray-pattern, particle-size, delivered-dose, and formulation data.

What formulation patents and related patents should be reviewed?

US 9,566,286 should be assessed as one part of the Enstilar patent estate. The relevant search should include patent families covering:

Calcipotriol-and-betamethasone compositions;
Anhydrous or substantially anhydrous topical formulations;
Aerosol foams and propellant systems;
Container linings and chemically compatible packages;
Valve assemblies and spray actuators;
Treatment of psoriasis using the combination;
Manufacturing, filling, and stability methods;
Pediatric or other method-of-use claims.

The claims supplied here do not establish that US 9,566,286 is the only patent protecting Enstilar. A product may remain exposed after this patent expires if a separate valid formulation or method-of-use patent has a later expiration date.

Which companies are challenging the patent?

The supplied record does not identify a named ANDA applicant, Paragraph IV notice, federal district-court action, PTAB proceeding, or settlement agreement involving US 9,566,286. A definitive challenger and litigation-status assessment cannot be made from the patent claims alone.

How strong is the patent estate for US 9,566,286?

The patent is strongest against a close-copy aerosol product that uses:

Calcipotriol or calcipotriol monohydrate;
Betamethasone dipropionate;
A dimethyl-ether-containing propellant;
A substantially anhydrous lipid-containing formulation;
An aluminum canister;
A polyimide-polyamide lining;
Conventional dip-tube valve hardware;
The claimed gasket, aperture, orifice, and valve-stem materials.

Its strength is lower against a product that changes the delivery platform or materially alters the package. Because claim 1 is an apparatus claim, the patent does not automatically reach every sale of the active composition. Infringement depends on whether the accused commercial product contains the full claimed container-composition combination.

How does this patent compare with ordinary drug patents?

US 9,566,286 differs from a conventional active-ingredient patent in three ways:

Patent type	Typical protected subject matter	Relevance of US 9,566,286
Compound patent	Chemical molecule	Not the subject of this patent
Formulation patent	Ingredients, concentrations, excipients, physical state	Partly present, but tied to a container
Device or combination patent	Package, valve, actuator, and product configuration	Primary character of this patent
Method-of-use patent	Treatment indication or dosing regimen	Not the principal claim type here

This structure can create a narrower infringement surface than a composition claim but a meaningful barrier to a highly similar aerosol product.

What manufacturing and IP barriers remain after expiration?

Manufacturing barriers may persist after patent expiration. The product requires control of:

Propellant filling and pressure;
Flammable solvent handling;
Canister-coating compatibility;
Valve and gasket extraction;
Dose uniformity;
Spray performance;
Long-term chemical stability;
Container-closure integrity;
Homogeneous distribution of poorly water-soluble actives.

These are regulatory and technical barriers rather than continuing patent rights. A competitor may avoid the patent and still face substantial development time, analytical work, supplier qualification, and FDA review.

Key Takeaways

US 9,566,286 is a container-composition combination patent associated with Enstilar.
Claim 1 requires a metal, internally lined pressurized container holding a substantially anhydrous calcipotriol/betamethasone spray composition.
Dimethyl ether, a lipid carrier, and the specified lining materials are central claim limitations.
Claims 2-19 narrow the invention through container metals, coatings, seals, dip tubes, valves, aperture dimensions, propellant ratios, and materials.
The expected ordinary patent expiration is approximately March 15, 2033.
Generic entry would most likely proceed through an ANDA, with Paragraph IV exposure if the patent remains Orange Book-listed.
Biosimilar competition is not relevant because Enstilar is a small-molecule topical product.
The principal design-around routes are a different container coating, propellant system, delivery format, or nonmetallic package.
The patent claims supplied do not establish the existence of a named challenger, litigation, or settlement.
Separate formulation, method-of-use, manufacturing, or device patents may affect entry after this patent expires.

FAQs

Does US 9,566,286 cover calcipotriol cream?

No. The claims require a pressurized container and sprayable composition. A conventional cream would not satisfy those structural limitations.

Does the patent cover betamethasone dipropionate by itself?

No. Claim 1 requires calcipotriol or calcipotriol monohydrate together with a betamethasone ester.

Can a generic use the same active ingredients with a different aerosol canister?

Potentially, but the alternative must be evaluated against every limitation of claim 1 and any other unexpired patent claims. A different canister coating or delivery configuration may provide a noninfringement position.

Is a product with propane instead of dimethyl ether covered?

Claim 1 requires dimethyl ether alone or in the claimed mixture. A propane-only product would not satisfy that limitation literally, although other patents or infringement theories could remain relevant.

Does patent expiration eliminate all Enstilar exclusivity?

No. Patent expiration removes only the rights conferred by that patent. FDA regulatory exclusivity, other listed patents, formulation patents, method-of-use patents, and manufacturing patents must be reviewed separately.

References

United States Patent and Trademark Office. (2017). US Patent No. 9,566,286 B2: Pressurized container comprising a pharmaceutical composition. U.S. Department of Commerce.
U.S. Food and Drug Administration. (2015). Enstilar prescribing information: Calcipotriene and betamethasone dipropionate aerosol foam. FDA.

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	9,566,286	⤷ Start Trial	Y				⤷ 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	2011264198	⤷ Start Trial
Brazil	112012030653	⤷ Start Trial
Canada	2800181	⤷ Start Trial
China	102939078	⤷ Start Trial
Cyprus	1115991	⤷ Start Trial
Denmark	2579852	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,566,286

Which drugs does patent 9,566,286 protect, and when does it expire?

Summary for Patent: 9,566,286