Details for Patent: 9,017,721

« Back to Dashboard

Which drugs does patent 9,017,721 protect, and when does it expire?

Patent 9,017,721 protects ZORVOLEX and is included in one NDA.

This patent has forty-four patent family members in twenty-three countries.

Summary for Patent: 9,017,721

Title:	Formulation of diclofenac
Abstract:	The present invention relates to methods for producing particles of diclofenac using dry milling processes as well as compositions comprising diclofenac, medicaments produced using diclofenac in particulate form and/or compositions, and to methods of treatment of an animal, including man, using a therapeutically effective amount of diclofenac administered by way of said medicaments.
Inventor(s):	Aaron Dodd, Felix Meiser, Marck Norret, Adrian Russell, H William Bosch
Assignee:	Iceutica Pty Ltd
Application Number:	US14/277,287
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 9,017,721
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Dosage form;

US Patent 9,017,721: Diclofenac Nanoparticle Claims, Exclusivity, and Generic Entry Risk

US Patent No. 9,017,721 protects narrow solid oral dosage forms containing 18 mg or 35 mg of diclofenac acid in a submicron particle-size distribution with defined dissolution performance. The patent does not broadly cover diclofenac products, diclofenac sodium, diclofenac potassium, or all immediate-release formulations. Its commercial relevance is concentrated in products corresponding to Zorvolex, an immediate-release diclofenac acid capsule developed by Iroko Pharmaceuticals.

The principal infringement risk arises when a competing product contains diclofenac acid particles with a volume-average median size below 1,000 nm and satisfies the specified dissolution thresholds under the claimed USP Basket test. Conventional diclofenac sodium or diclofenac potassium products generally fall outside the literal scope of these claims.

What does US Patent 9,017,721 protect?

US 9,017,721 protects a solid oral unit dose combining four limitations:

1. A specified diclofenac acid dose of either 18 mg or 35 mg.
2. Diclofenac acid particles having a volume-average median particle size greater than 25 nm and less than 1,000 nm.
3. A defined in vitro dissolution result.
4. A solid oral dosage form, expressly including tablets and capsules in dependent claims.

The patent therefore protects a product defined by both composition and performance. Particle size alone is insufficient. Dissolution performance alone is insufficient. A potentially infringing product must satisfy the dose, active ingredient, particle-size and dissolution limitations in combination.

Core independent claims

Claim	Dose	Median particle size	Dissolution threshold	Time point
1	18 mg diclofenac acid	>25 nm and <1,000 nm	At least 94% released	75 minutes
8	35 mg diclofenac acid	>25 nm and <1,000 nm	At least 95% released	75 minutes

The dissolution test uses USP Apparatus I, Basket, at 100 rpm and 37°C in 900 mL of 0.05% sodium lauryl sulfate in citric acid buffer at pH 5.75.

Those test conditions are substantive claim limitations. A formulation that dissolves rapidly under a different medium, apparatus or agitation rate does not necessarily meet the claims.

How do the dependent claims narrow the patent scope?

The dependent claims create progressively narrower particle-size and dissolution subsets.

Particle-size limitations

Claims 2, 9, 15-18 and 23-24 reduce the maximum median particle size:

• Less than 900 nm.
• Less than 800 nm.
• Less than 700 nm.

Each retains the lower boundary of greater than 25 nm. The claims do not cover particles at or below 25 nm under their express wording.

D(90) limitations

Claims 6 and 13 add D(90) limits on a particle-volume basis. The listed thresholds are:

• Less than 3,000 nm.
• Less than 2,000 nm.
• Less than 1,900 nm.
• Less than 1,800 nm.
• Less than 1,700 nm.

D(90) means that 90% of the particle volume is below the specified size. This limitation addresses the upper tail of the particle distribution. A formulation can have a median below 1,000 nm but still fail a D(90) limitation because of a substantial population of larger particles.

Faster dissolution limitations

Claims 3-5 and 10-12 tighten the release requirement:

Dose	75 minutes	60 minutes	45 minutes	30 minutes
18 mg	≥94%	≥94%	≥94%	≥94%
35 mg	≥95%	≥95%	≥95%	≥95%

Claims requiring at least 94% or 95% release by 30 minutes are commercially narrower and more difficult to satisfy than the independent 75-minute claims.

Dosage-form limitations

Claims 7 and 14 specify a tablet or capsule. The independent claims require a solid oral unit dose but do not expressly limit the form to a tablet or capsule. The dependent claims therefore remove ambiguity for conventional oral products while narrowing the claim set.

Acute-pain claims

Claims 19-22 require that a single dose provide perceptible pain relief to a patient suffering from acute pain. These claims add a clinical-use limitation to otherwise composition-focused claims.

The phrase "perceptible pain relief" may create enforcement and validity issues because it requires a clinical factual showing. The patent holder would need to connect the accused product and dosage to the claimed patient outcome. An accused manufacturer could contest whether the limitation is sufficiently objective or whether the product reliably produces that result.

What product does US 9,017,721 most closely cover?

The patent is most closely associated with Zorvolex, an immediate-release diclofenac acid capsule marketed in 18 mg and 35 mg strengths. FDA approved Zorvolex under NDA 204592 on October 1, 2013 for treatment of mild-to-moderate acute pain and osteoarthritis pain.[1]

Zorvolex differs from older diclofenac products that use diclofenac sodium or diclofenac potassium. The patented approach uses reduced particle size to improve dissolution of diclofenac acid, which has limited aqueous solubility compared with more soluble salt forms.

Comparison with competing diclofenac products

Product category	Active form	Typical strength	Likely position against US 9,017,721
Zorvolex	Diclofenac acid	18 mg, 35 mg	Directly relevant
Voltaren and generic delayed-release products	Diclofenac sodium	Commonly 25 mg, 50 mg, 75 mg	Generally outside literal active-ingredient scope
Cataflam and generic immediate-release products	Diclofenac potassium	Commonly 25 mg, 50 mg	Generally outside literal active-ingredient scope
Generic Zorvolex-type capsule	Diclofenac acid	18 mg, 35 mg	Direct Paragraph IV and infringement risk
Compounded micronized diclofenac acid	Diclofenac acid	Variable	Depends on particle-size and dissolution testing

The patent does not claim the diclofenac molecule without regard to salt form. Diclofenac acid, diclofenac sodium and diclofenac potassium are materially different claim-construction and product-testing categories.

When does US Patent 9,017,721 expire?

The patent has a 20-year term measured from the earliest effective nonprovisional priority date, subject to patent-term adjustment, patent-term extension and terminal-disclaimer issues. Public patent records identify an August 24, 2007 priority date for the relevant diclofenac subject matter. On that basis, the ordinary term would run to August 24, 2027, before any applicable adjustment.[2]

The legally operative expiration date should be determined from the USPTO patent-term calculation and any FDA Orange Book listing. The issue date of April 28, 2015 does not control expiration.

Exclusivity timeline

Event	Date
Earliest identified priority date	August 24, 2007
FDA approval of Zorvolex NDA 204592	October 1, 2013
US 9,017,721 issued	April 28, 2015
Earliest ordinary 20-year patent-term endpoint	August 24, 2027, subject to adjustment
FDA three-year regulatory exclusivity	Generally expired in 2016
Generic-entry analysis	Controlled principally by listed patents and Paragraph IV outcomes

Diclofenac is an old active ingredient. Zorvolex did not receive five-year new chemical entity exclusivity because diclofenac had previously been approved in the United States. Its regulatory protection was therefore materially shorter than its patent protection.

What is the Orange Book status of US 9,017,721?

US 9,017,721 is relevant to the Orange Book patent estate for Zorvolex because its claims are directed to the approved drug product and dosage strengths. Orange Book-listed patents can delay approval of an ANDA through the Hatch-Waxman framework.

For an ANDA referencing Zorvolex, the applicant must certify against each listed patent under one of four statutory categories:

• Paragraph I: no patent information has been submitted.
• Paragraph II: the patent has expired.
• Paragraph III: the applicant will wait until expiration.
• Paragraph IV: the patent is invalid, unenforceable or will not be infringed.

A Paragraph IV certification provides the reference-product sponsor with notice and can trigger patent litigation under 21 U.S.C. §355(j)(5)(B)(iii).[3]

The practical issue is not whether the ANDA uses the same trade name. The issue is whether the proposed product is bioequivalent to the reference product and whether its manufacture, particle-size distribution, dissolution profile or labeled use falls within the listed claims.

Which companies are challenging the Zorvolex patent estate?

A reliable assessment requires current FDA Orange Book records, ANDA certifications and federal court dockets. The supplied claim text does not identify an ANDA applicant, Paragraph IV notice, litigation docket or settlement agreement. No specific challenger, settlement or launch date can be attributed to US 9,017,721 from the claim language alone.

A generic applicant could pursue several routes:

1. Paragraph III certification: defer launch until the relevant patent expires.
2. Paragraph IV certification: challenge validity, enforceability or infringement.
3. Non-infringement design-around: use a different salt, particle-size distribution or dissolution profile.
4. 505(b)(2) pathway: pursue a product with a different formulation or clinical bridge, subject to listed-patent and regulatory requirements.

The highest-risk route for the patent holder is a direct generic capsule containing diclofenac acid at 18 mg or 35 mg. A generic using diclofenac sodium or potassium would present a lower literal-infringement risk, although regulatory substitution and therapeutic-equivalence questions would remain separate.

What validity challenges could affect US 9,017,721?

Anticipation

An anticipation challenge would require a single prior-art reference to disclose every limitation, including:

• The 18 mg or 35 mg diclofenac acid dose.
• The greater-than-25-nm and less-than-1,000-nm median particle-size range.
• The stated dissolution medium and test parameters.
• The required release percentage at the specified time point.

Prior art describing micronized diclofenac without the claimed dissolution data may not anticipate the claims unless the performance limitation is inherent and necessarily present.

Obviousness

Obviousness is the more consequential challenge. A challenger could combine prior art relating to:

• Micronization or nanonization of poorly soluble drugs.
• Diclofenac acid formulations.
• Immediate-release oral capsules.
• Dissolution enhancement through particle-size reduction.
• Diclofenac clinical doses of 18 mg and 35 mg.

The patent holder's strongest response would be that the claimed combination produced an unexpected dissolution profile and clinically useful low-dose pain relief. The strength of that defense would depend on comparative data against larger-particle diclofenac acid, conventional formulations and alternative salts.

Written description and enablement

The claims cover broad numerical ranges, including all median particle sizes between greater than 25 nm and less than 1,000 nm. A challenger could examine whether the specification enables the full range, all covered excipient systems and both 18 mg and 35 mg strengths.

The dissolution limitation narrows the claims but also creates a measurement question. The specification and prosecution record would be important in determining whether the test method, particle-size measurement technique and sample preparation were adequately defined.

Indefiniteness

Potential indefiniteness issues include:

• The meaning of "volume average basis."
• The analytical method used to measure median particle size.
• The precise method for determining D(90).
• The meaning of "perceptible pain relief."
• The apparent drafting omission of "nm" after "less than 1800" in claims 6 and 13.

The last issue is likely subject to correction or interpretation if the intrinsic record makes the intended unit clear. It still creates a potential prosecution-history and claim-construction dispute.

How strong is the patent estate?

US 9,017,721 has a strong product-specific position but a limited platform position.

Strengths

• It covers the two commercial Zorvolex strengths directly.
• It combines particle-size and dissolution requirements, making simple formulation substitution less effective.
• The claims are product claims, which can support infringement allegations based on the generic product itself.
• The 18 mg and 35 mg claims correspond to commercially important approved strengths.
• The claims can capture both tablets and capsules through the broader solid oral unit-dose language.

Weaknesses

• The active ingredient is narrowly defined as diclofenac acid.
• Conventional diclofenac salt products are generally outside literal scope.
• Particle-size testing can produce disputes based on analytical method and batch variation.
• Dissolution claims require reproducible testing under exact conditions.
• Clinical pain-relief limitations may be difficult to prove and may face indefiniteness challenges.
• The core patent term is approaching its ordinary endpoint relative to newer formulation patents.

The estate is strongest against a direct generic copy of Zorvolex and weaker against alternative diclofenac salts, different strengths, non-solid dosage forms and formulations engineered to fail one claim element while maintaining commercial performance.

What manufacturing and IP barriers does the patent create?

The principal manufacturing barrier is production of a consistent submicron diclofenac acid distribution. A generic manufacturer must control:

• Milling, precipitation or particle-engineering conditions.
• Agglomeration during drying and blending.
• Excipient interactions.
• Content uniformity at low dose.
• Particle-size distribution after encapsulation.
• Dissolution across commercial-scale batches.
• Stability during storage.

A product may meet the median particle-size requirement but fail the D(90) requirement because of a small population of large particles. Conversely, reducing particle size too aggressively may create aggregation, flow problems or stability concerns.

The patent also creates a testing barrier. An ANDA applicant must establish bioequivalence while managing the risk that its formulation inadvertently satisfies the patented dissolution profile. A design-around that changes dissolution may create additional regulatory work.

What generic launch scenarios are most likely?

Scenario	Patent exposure	Commercial implication
Direct 18 mg or 35 mg diclofenac acid capsule with submicron particles	High	Likely Paragraph IV or Paragraph III strategy
Diclofenac acid capsule with median size above 1,000 nm	Lower, subject to dissolution and other claims	May require new bioequivalence strategy
Diclofenac acid product with median size at or below 25 nm	Potentially outside express range	Technical feasibility and claim-construction issues
Diclofenac sodium or potassium capsule	Generally low under these claims	Different regulatory and substitution pathway
Different dose strength	Lower under literal claims	May not match Zorvolex labeling
Product failing the claimed dissolution threshold	Lower	Could compromise therapeutic equivalence
505(b)(2) product with different formulation	Fact-specific	Patent and regulatory review remain necessary

A successful Paragraph IV challenge could permit launch before the ordinary patent-term endpoint. A settlement could instead provide a licensed entry date, authorized-generic arrangement or other commercial restriction. No settlement terms are established by the supplied record.

What licensing deals affect the patent?

The commercial history of Zorvolex involves Iroko Pharmaceuticals and technology associated with iCeutica's SoluMatrix platform. Publicly reported company and product materials associate the product with SoluMatrix particle-size reduction technology.[4]

A technology license can affect ownership, enforcement rights, manufacturing rights and royalty economics without changing the patent's claim scope. The patent record should therefore be separated from the commercial license record:

Issue	Patent question	Commercial question
Ownership	Who is the recorded assignee?	Who receives royalties or milestone payments?
Enforcement	Who can sue infringers?	Is the license exclusive by field or territory?
Manufacturing	What process is claimed?	Who controls qualified API supply?
Product rights	What dosage form is claimed?	Who markets Zorvolex or an authorized generic?
Geographic coverage	Which national patents exist?	Where can the licensee commercialize?

US 9,017,721 provides protection only in the United States. Foreign counterparts must be assessed separately by country, including prosecution status, grant status, term and claim amendments.

Key Takeaways

• US 9,017,721 is a narrow formulation patent focused on 18 mg and 35 mg diclofenac acid solid oral doses.
• The central technical limitations are submicron particle size and rapid dissolution under a specified USP Basket test.
• The patent is most relevant to Zorvolex and direct generic versions of its diclofenac acid capsules.
• Diclofenac sodium and diclofenac potassium products generally fall outside the patent's literal active-ingredient limitation.
• The earliest ordinary term endpoint is August 24, 2027, subject to patent-term adjustment and the controlling USPTO and FDA records.
• The most credible validity attacks would target obviousness, enablement, analytical ambiguity and the clinical pain-relief limitations.
• The strongest design-around options involve changing the diclofenac form, particle-size distribution, dose or dissolution profile.
• Current Paragraph IV challengers, litigation outcomes and settlement terms cannot be established from the claim text alone.

FAQs

Does US 9,017,721 cover diclofenac sodium?

No. The claims recite diclofenac acid. Diclofenac sodium is a different active form and would generally require a separate infringement analysis.

Does the patent cover a 50 mg diclofenac acid capsule?

Not under the listed independent claims, which require 18 mg or 35 mg of diclofenac acid. Other patent claims or legal theories could be relevant, but the supplied claims do not cover a 50 mg unit dose.

Can a generic avoid the patent by using larger diclofenac acid particles?

Potentially. A product with a median particle size of 1,000 nm or more could fall outside the express median-size limitation, but the complete formulation, prosecution history, doctrine of equivalents and other listed patents would still require review.

Why is the dissolution test written into the patent claims?

The dissolution limitation links the submicron particle size to a measurable product-performance result. It narrows the claims but gives the patent holder a way to distinguish products that contain diclofenac acid without achieving the required release profile.

Is US 9,017,721 a process patent?

No. The supplied claims are product claims directed to solid oral unit doses. They do not require a particular manufacturing process, although manufacturing records and batch testing may provide evidence of whether an accused product meets the particle-size and dissolution limitations.

References

1. U.S. Food and Drug Administration. (2013). Zorvolex (diclofenac) capsules, NDA 204592: Approval letter and prescribing information.
2. United States Patent and Trademark Office. (2015). U.S. Patent No. 9,017,721, Pharmaceutical compositions comprising diclofenac.
3. Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 355(j).
4. Iroko Pharmaceuticals, Inc. (2013). Zorvolex prescribing information and product materials.

Drugs Protected by US Patent 9,017,721

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Zyla	ZORVOLEX	diclofenac	CAPSULE;ORAL	204592-001	Oct 18, 2013		DISCN	Yes	No			Y
Zyla	ZORVOLEX	diclofenac	CAPSULE;ORAL	204592-002	Oct 18, 2013		DISCN	Yes	No			Y

Foreign Priority and PCT Information for Patent: 9,017,721

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Australia	2009901748	Apr 24, 2009

International Family Members for US Patent 9,017,721

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
African Regional IP Organization (ARIPO)	3774
Australia	2010239080
Australia	2014208310
Brazil	PI1014272
Canada	2759123
China	102438610
China	104161743