US Patent 9,447,089: Posaconazole Solid-Dispersion Claims, Exclusivity, and Patent Landscape

US Patent No. 9,447,089 protects a solid dispersion of posaconazole, marketed as Noxafil, in which substantially amorphous posaconazole is molecularly dispersed in hydroxypropylmethyl cellulose acetate succinate, or HPMCAS. The commercially important embodiment is a 3:7 posaconazole-to-HPMCAS weight ratio incorporated into a coated tablet.

The patent is formulation-focused. It does not broadly protect posaconazole as a chemical entity, every posaconazole formulation, or every amorphous posaconazole product. Infringement depends on whether a competing product contains the claimed HPMCAS matrix, amorphous drug state, concentration or ratio, and, for narrower claims, the specified tablet and stability characteristics.

What does US Patent 9,447,089 protect?

US 9,447,089 protects posaconazole dispersed in HPMCAS in a substantially amorphous solid state. The patent's claims cover four principal layers:

Claim group	Protected subject matter	Commercial relevance
Claims 1-12	Posaconazole-HPMCAS solid dispersion	Core formulation technology
Claims 13-19	Formulations and tablets containing the dispersion	Finished dosage form
Claims 20-29	Coated tablets using an approximately 3:7 posaconazole:HPMCAS ratio	Closest claims to the Noxafil delayed-release tablet

The underlying Compound I is posaconazole. The formula is omitted from the claim text supplied, but the HPMCAS matrix, amorphous-state limitations, tablet composition, and stability testing correspond to the delayed-release posaconazole formulation commercialized by Merck.

The patent was assigned to the Merck group, historically identified in related records as Schering Corporation or Merck Sharp & Dohme Corp. The patent issued on September 20, 2016.

How broad is independent claim 1?

Claim 1 is the broadest technical claim in the set. It requires:

A solid dispersion.
Posaconazole as Compound I.
Molecular dispersion of the drug within an HPMCAS polymer matrix.
A solid-state product.
Substantially amorphous posaconazole.

Claim 1 does not require a tablet, coating, specific drug loading, particular HPMCAS grade, or stated stability period. A product could fall within claim 1 without meeting the narrower limitations in claims 2-12 and 20-29.

The key infringement issues are technical rather than merely compositional. A generic manufacturer could avoid claim 1 by using:

A crystalline form of posaconazole rather than substantially amorphous posaconazole.
A polymer other than HPMCAS.
A physical mixture rather than a molecularly dispersed solid dispersion.
A solution, suspension, lipid formulation, or nanoparticle system that does not contain the claimed HPMCAS matrix.
A different manufacturing process that produces a different solid-state structure.

The claim does not require a particular method of producing the dispersion. Spray drying, hot-melt extrusion, solvent evaporation, and other techniques could potentially fall within the claim if the resulting product satisfies the structural limitations.

What concentration and ratio ranges are protected?

Claims 3-8 and 10-12 establish overlapping drug-loading and polymer-ratio limitations.

Claim	Limitation
3	Posaconazole is about 20%-60% by weight
4	Posaconazole is about 20%-40% by weight
6	Posaconazole:HPMCAS ratio of about 1:9 to 1:1
7	Posaconazole:HPMCAS ratio of about 2:8 to 4:6
8	Posaconazole:HPMCAS ratio of about 3:7
10	HPMCAS is at least about 20% by weight
11	HPMCAS is greater than about 50% by weight
12	HPMCAS is about 20%-70% by weight

The 3:7 ratio in claim 8 and claim 20 is the most commercially important limitation. At that ratio, the solid dispersion contains approximately 30% posaconazole and 70% HPMCAS, subject to how the formulation is measured and whether additional excipients are excluded from the dispersion calculation.

Claims 3 and 4 are composition-based percentage claims. Claims 6-8 use a ratio between posaconazole and HPMCAS. Those limitations are related but are not interchangeable in every formulation because the denominator differs. A manufacturer could satisfy one percentage claim while disputing a ratio claim, depending on the formulation architecture and analytical method.

What HPMCAS grades are covered?

Claim 9 covers six HPMCAS grades:

AS-LF
AS-MF
AS-HF
AS-LG
AS-MG
AS-HG

These grades are differentiated primarily by substitution characteristics and viscosity or grade designation. The claim does not require one particular grade. Use of a listed grade can satisfy claim 9 if the other limitations are met.

Claim 1 is broader than claim 9 because it requires HPMCAS but does not expressly restrict the polymer to those six grades. A product using another HPMCAS grade could therefore face claim 1 while avoiding claim 9, assuming the product meets the remaining limitations.

HPMCAS is a precipitation-inhibiting polymer used to improve dissolution and maintain supersaturation of poorly water-soluble drugs. In the claimed product, it also acts as the physical matrix that stabilizes amorphous posaconazole.

What amorphous-state limitations apply?

The claims use several different amorphous-state standards:

Claim	Amorphous limitation
1	Posaconazole is substantially amorphous
5	At least 98% of posaconazole is amorphous
25	At least 95% remains amorphous after stability testing
26	At least 98% remains amorphous after stability testing
28	No detectable crystalline peaks by powder X-ray diffraction

Claim 5 is important because claims 13-19 depend on a dispersion meeting claim 5. A formulation that contains amorphous posaconazole but does not establish at least 98% amorphous content may not satisfy those dependent claims.

Claims 25-28 introduce post-manufacture stability requirements. Claim 28 is particularly stringent in practical terms because it requires no detectable crystalline peaks by powder X-ray diffraction. The result depends on the detection limit, sample preparation, instrument settings, and analytical method.

A competitor's product would likely be tested using:

Powder X-ray diffraction.
Differential scanning calorimetry.
Assay and related-substances testing.
Dissolution testing.
Accelerated stability studies at 40°C and 75% relative humidity.

The claim language does not define a universal powder-X-ray diffraction detection threshold. That issue could become material in infringement litigation.

What formulations and tablets are protected?

Claims 13-19 cover formulations containing the claim 5 dispersion. They extend protection beyond the dispersion itself to finished products.

The relevant limitations include:

A pharmaceutical formulation.
A tablet or coated tablet.
Colloidal silicon dioxide.
At least 0.5% colloidal silicon dioxide by formulation weight.
Approximately 2% hydroxypropylcellulose.
A pharmaceutically acceptable carrier.

Claims 20-29 are narrower but commercially significant. They require a tablet containing a solid dispersion with:

Substantially amorphous posaconazole.
HPMCAS as the polymer matrix.
Approximately a 3:7 posaconazole:HPMCAS ratio.

The tablet can be coated under claim 21. Claims 22-29 then add stability requirements, including stability for at least two or three months at 40°C and 75% relative humidity.

The presence of colloidal silicon dioxide or hydroxypropylcellulose is not required by every tablet claim. A product could potentially infringe claim 20 or claim 21 without infringing claims 16-18.

What is the FDA and Orange Book status of Noxafil?

Noxafil is FDA-approved in several dosage forms, including delayed-release tablets, oral suspension, and injectable formulation. The delayed-release tablet contains 100 mg posaconazole and uses a polymer-based formulation designed to improve exposure and reduce the food dependence associated with the oral suspension.[2]

The Orange Book distinguishes listed patents from regulatory exclusivity. US 9,447,089 is a formulation patent associated with the Noxafil delayed-release tablet franchise, rather than an original active-ingredient patent. Orange Book listing alone does not determine claim validity or infringement, but an FDA-listed patent can support a Paragraph IV certification and a statutory 30-month stay if the patent holder timely files suit.[3]

The original new chemical entity exclusivity for posaconazole has expired. The commercial barrier now depends primarily on listed formulation and dosage-form patents, pediatric exclusivity where applicable, regulatory review, and the ability of a generic applicant to obtain approval for a particular dosage form.

When does US 9,447,089 lose exclusivity?

The expected statutory patent term runs into 2031, based on the patent family's 2011 filing period and the 20-year term applicable to the relevant US application. The precise expiration date must be read with the patent's term-adjustment calculation and any applicable patent-term extension or disclaimer data.[1]

Item	Date or status
Patent	US 9,447,089
Issue date	September 20, 2016
Technology	Posaconazole amorphous solid dispersion
Core polymer	HPMCAS
Key ratio	Approximately 3:7 posaconazole:HPMCAS
Expected statutory term	2031, before any applicable adjustment
Regulatory exclusivity	Original NCE exclusivity expired
Commercial product	Noxafil delayed-release tablet

Unlike a chemical-entity patent, this patent's practical value depends on whether a generic product uses the same formulation architecture. A non-infringing alternative formulation could enter before the patent's expected expiration if approved and supported by the relevant FDA pathway.

Which patents compete with US 9,447,089 in the posaconazole estate?

The posaconazole estate includes several patent categories:

Patent category	Function	Relevance to generic entry
Chemical-entity patents	Protect posaconazole and related triazole compounds	Historical protection; generally expired or near expiration
Oral formulation patents	Protect improved absorption or dosage forms	Can delay suspension or tablet competition
Delayed-release tablet patents	Protect the marketed tablet architecture	Directly relevant to ANDA applicants
Solid-dispersion patents	Protect amorphous posaconazole in polymer matrices	US 9,447,089's primary domain
Process patents	Protect preparation of the dispersion or tablet	May create manufacturing barriers
Stability or solid-state patents	Protect physical form and storage performance	Can support narrower infringement theories

The most relevant comparison is between a generic delayed-release tablet using an HPMCAS dispersion and a generic product using a different delivery technology. The first faces a higher risk under US 9,447,089. The second may avoid the patent but must establish bioequivalence and comparable clinical performance.

What Paragraph IV challenges and litigation risks exist?

A generic applicant seeking approval before the expiration of a listed formulation patent may submit a Paragraph IV certification alleging that the patent is invalid, unenforceable, or not infringed. For US 9,447,089, likely technical defenses would focus on:

The product does not contain molecularly dispersed posaconazole.
The drug is not substantially amorphous or does not meet the 98% threshold.
The polymer matrix is not HPMCAS.
The drug-to-polymer ratio falls outside the claimed range.
The product does not satisfy the coated-tablet or stability limitations.
The patent claims are obvious over prior amorphous dispersions using HPMCAS.
The claims lack adequate written description or enablement across the full breadth of the claimed ranges.

The patent holder would likely rely on:

Product sampling and reverse engineering.
Powder-X-ray diffraction.
Solid-state spectroscopy.
Polymer identification.
Drug-loading analysis.
Dissolution and accelerated-stability data.
The relationship between the generic's ANDA formulation and the reference listed drug.

A Paragraph IV certification can trigger patent litigation and an FDA approval stay of up to 30 months under the Hatch-Waxman framework. The stay does not extend the patent term and can be shortened by court action or resolved by judgment or settlement.[3]

No conclusion about a particular generic manufacturer's infringement position follows from the claim text alone. The ANDA formulation, certification, Orange Book listing, and court docket must be evaluated together.

How strong is the patent estate?

US 9,447,089 is strongest against a generic that copies the commercial formulation closely. Its strongest commercial limitations are the combination of:

Posaconazole.
Substantially amorphous drug.
HPMCAS matrix.
Approximately 3:7 drug-to-polymer ratio.
Tablet or coated-tablet presentation.
Stability under accelerated conditions.

Its scope is weaker against a formulation that uses:

A non-HPMCAS polymer.
Crystalline posaconazole.
A substantially different drug loading.
A non-tablet dosage form.
A lipid or self-emulsifying delivery system.
A different manufacturing process that does not produce molecular dispersion.

The patent has meaningful formulation value because a generic manufacturer cannot assess infringement solely by reviewing the label. The relevant limitations may be hidden in the product's composition and solid-state structure. That creates discovery and analytical costs even where the finished product has the same active ingredient and strength.

What generic launch scenarios exist?

Scenario 1: HPMCAS-based delayed-release tablet

This is the highest-risk route. A product with approximately 30% amorphous posaconazole and 70% HPMCAS could implicate claims 1, 5, 8, 13, 20, and potentially 21-29.

Scenario 2: HPMCAS formulation outside the 3:7 ratio

This may avoid claim 8 and claim 20, but claim 1 and the broader loading ranges could remain relevant. Ratio changes must be large enough to avoid overlapping "about" language and the broader claims.

Scenario 3: Alternative polymer

A formulation based on a different polymer may avoid the express HPMCAS limitation. It would still require FDA support for bioequivalence, dissolution, stability, and food-effect performance.

Scenario 4: Crystalline posaconazole product

A crystalline product may avoid the amorphous-dispersion claims. It could face separate solid-form, formulation, or process patents.

Scenario 5: Non-tablet dosage form

An oral suspension, capsule, or injectable product may avoid tablet-specific claims but could face other patents and different regulatory requirements.

Key Takeaways

US 9,447,089 is a formulation patent directed to amorphous posaconazole in an HPMCAS solid dispersion.
Claim 1 broadly requires molecularly dispersed, substantially amorphous posaconazole in an HPMCAS matrix.
The key commercial embodiment uses an approximately 3:7 posaconazole-to-HPMCAS ratio.
Claims 20-29 are narrower and target the coated-tablet product and accelerated-stability profile.
The patent does not broadly cover all posaconazole products.
A generic using a different polymer, crystalline posaconazole, or a materially different formulation may have a stronger non-infringement position.
The expected statutory term extends into 2031, subject to the official patent-term calculation.
Paragraph IV exposure is highest for an ANDA product that copies the Noxafil delayed-release tablet's polymer matrix, drug loading, amorphous state, and tablet architecture.
The patent's practical strength comes from product characteristics that require reverse engineering to evaluate.

FAQs

Does US 9,447,089 cover posaconazole itself?

No. It covers a particular pharmaceutical presentation of posaconazole: a substantially amorphous solid dispersion in an HPMCAS matrix. Chemical-entity protection is a separate patent category.

Can a generic use HPMCAS without infringing US 9,447,089?

Potentially, but HPMCAS use alone does not determine infringement. The generic product would also need to be evaluated for molecular dispersion, amorphous content, drug loading, ratio, dosage form, and other claim limitations.

Is a 30% posaconazole formulation automatically covered?

No. A 30% drug loading may correspond to the approximate 3:7 ratio, but infringement also depends on whether posaconazole is substantially amorphous and molecularly dispersed in HPMCAS.

Does powder X-ray diffraction alone prove infringement?

Not necessarily. Powder X-ray diffraction is expressly identified in the claims for certain stability determinations, but infringement may require a broader analysis of polymer identity, molecular dispersion, composition, and amorphous content.

Can a company launch an alternative posaconazole formulation before 2031?

Potentially. A formulation that avoids the claimed HPMCAS amorphous-dispersion architecture may not infringe US 9,447,089, but it remains subject to other listed patents, FDA approval requirements, bioequivalence standards, and any applicable litigation or settlement restrictions.

References

United States Patent and Trademark Office. (2016). US Patent No. 9,447,089, solid dispersion comprising Compound I.
U.S. Food and Drug Administration. (2023). Noxafil (posaconazole) prescribing information. Merck Sharp & Dohme LLC.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Food and Drug Administration. (2017). Guidance for industry: 180-day exclusivity when multiple ANDA applicants submit substantially complete ANDAs.
U.S. Patent and Trademark Office. (2024). Patent term adjustment and patent term extension records.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Hoffmann La Roche	ZELBORAF	vemurafenib	TABLET;ORAL	202429-001	Aug 17, 2011		RX	Yes	Yes	⤷ Start Trial	⤷ 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

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	09175665	Nov 11, 2009

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	078033	⤷ Start Trial
Argentina	121037	⤷ Start Trial
Australia	2010232670	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,447,089

Which drugs does patent 9,447,089 protect, and when does it expire?

Summary for Patent: 9,447,089