US Patent 9,693,979: Claim Scope, Naproxen Softgel Coverage, Expiration Risk and Patent Landscape

US Patent 9,693,979 protects a specific naproxen sodium softgel platform rather than naproxen sodium generally. The independent claims require a soft gelatin capsule containing a liquid matrix with naproxen sodium, approximately 5% lactic acid, polyethylene glycol, and specified solubilizers. The strongest commercial coverage is concentrated in claims 8, 15, 17 and their dependent claims, which narrow the formulation to approximately 25% naproxen sodium, PEG 600, polyvinylpyrrolidone, propylene glycol, and a lactic-acid-to-naproxen-sodium mole ratio of approximately 0.6.

The patent does not, on the supplied claims, cover conventional naproxen tablets, ordinary naproxen sodium capsules, enteric-coated products, or every liquid naproxen formulation. Infringement risk turns on the complete formulation, the capsule dosage form, the quantitative ranges, and whether the accused product practices a claimed manufacturing method.

What does US Patent 9,693,979 protect?

The patent claims a liquid-filled softgel formulation designed to solubilize naproxen sodium in a polyethylene glycol-based matrix.

Claim group	Principal subject matter	Commercial significance
Claims 1-7	Broad composition claim with naproxen sodium, approximately 5% lactic acid, PEG and specified solubilizers	Main platform claim
Claims 8-14	Narrow composition with approximately 25% naproxen sodium, approximately 5% lactic acid, PEG 600 and solubilizer	Core product formulation
Claims 15-16	Method of mixing and rotary-die encapsulation, plus dosage form made by that method	Manufacturing and product-by-process coverage
Claims 17-19	Alternative composition using q.s. PEG 600, with the same naproxen, lactic-acid and solubilizer structure	Backup formulation coverage

The independent composition claims require a soft gelatin capsule. A liquid matrix outside a softgel generally does not meet the express capsule limitation, although other patent claims or legal theories could apply if the product is made through a claimed process.

How broad are the independent claims?

Claim 1: platform composition

Claim 1 requires all of the following:

A pharmaceutical composition.
A soft gelatin capsule.
A liquid matrix encapsulated in the capsule.
Naproxen sodium.
Approximately 5% lactic acid by matrix weight.
One or more polyethylene glycols.
A solubilizer comprising polyvinylpyrrolidone, propylene glycol, or both.

The claim does not require a specific naproxen sodium concentration, a particular PEG molecular weight, a specific capsule fill weight, or a specific pH. Those limitations appear in dependent claims.

The phrase "about 5%" creates numerical scope around the lactic acid concentration. Its exact boundary would depend on intrinsic evidence, prosecution history, specification examples and expert testimony. A formulation with 4.8% or 5.2% lactic acid could present greater risk than one with 2% or 8%, but the claim cannot be reduced to a single universal tolerance without the patent’s prosecution record and specification.

Claim 8: principal commercial formulation claim

Claim 8 is more technically specific. It requires:

About 25% naproxen sodium by matrix weight;
About 5% lactic acid;
About 10% to about 80% PEG 600; and
About 1% to about 10% PVP, propylene glycol, or a combination.

The claim covers a broad fill-composition window. It does not require both PVP and propylene glycol because the solubilizer may comprise either compound or a combination. It also does not require the approximately 0.6 lactic-acid-to-naproxen-sodium mole ratio in the independent claim. That ratio is added by claim 10.

Claim 17: q.s. PEG 600 formulation

Claim 17 replaces the numerical PEG range in claim 8 with "quantum sufficit," meaning enough PEG 600 to complete the matrix or provide the intended formulation quantity. It retains:

Approximately 25% naproxen sodium;
Approximately 5% lactic acid; and
Approximately 1% to 10% PVP, propylene glycol or both.

Claim 17 may provide broader practical protection than claim 8 because it does not expressly require PEG 600 to comprise 10% to 80% of the matrix. Its scope remains constrained by the other required ingredients and the softgel dosage form.

What formulations are protected by US 9,693,979?

The formulation most directly targeted by the claim set is a naproxen sodium softgel with a liquid PEG 600 fill and a mixed PVP/propylene glycol solubilizer system.

Formulation element	Claim 1	Claim 8	Claim 17
Naproxen sodium	Required	About 25%	About 25%
Lactic acid	About 5%	About 5%	About 5%
PEG	Required	PEG 600, about 10%-80%	PEG 600, q.s.
PVP or propylene glycol	Required	About 1%-10%	About 1%-10%
PVP and propylene glycol together	Optional	Optional	Optional
Soft gelatin capsule	Required	Required	Required
Liquid matrix	Required	Required	Required
pH 2.5-7.5	Not required	Added by claim 13	Not required
Lactic acid:naproxen sodium mole ratio of about 0.6	Not required	Added by claim 10	Added by claim 19

Claim 6 and claim 11 specify approximately 2% PVP and approximately 2% propylene glycol. Those claims are commercially important because they identify a narrower formulation that may correspond to an example or preferred embodiment.

Claim 14 limits the softgel shell to gelatin, plasticizer and purified water. A shell using additional conventional ingredients may still fall within claim 8 or claim 17 because the shell limitation in those claims is simply a soft gelatin capsule.

How do the dependent claims change infringement analysis?

A product that falls outside a dependent claim may still infringe the independent claim.

For example:

A product with PEG 400 may avoid claim 4, but it may still fall within claim 1 or claim 8 if the claim’s PEG requirement is otherwise met.
A product with only PVP may avoid claims requiring both PVP and propylene glycol, but claim 1 expressly permits PVP alone.
A product outside the pH range of 2.5 to 7.5 may avoid claim 13, but claim 8 does not require that pH range.
A softgel shell using sorbitol or another plasticizer may avoid claim 14, but may remain within claims 8 or 17.
A formulation with 15% PEG 600 may fall outside claim 8 if the court gives effect to the lower "about 10%" boundary, but it could remain within claim 17.

This claim structure creates layered protection. The broad platform claim is supported by narrower concentration, ingredient, pH, shell and process claims.

What manufacturing steps are protected?

Claim 15 requires:

Mixing the components identified in claim 10(a) through 10(d); and
Encapsulating the resulting mixture in a soft gelatin capsule using rotary die encapsulation.

The referenced components are the formulation elements in claim 8: approximately 25% naproxen sodium, approximately 5% lactic acid, approximately 10%-80% PEG 600 and approximately 1%-10% PVP, propylene glycol or both.

Claim 16 covers an oral dosage form produced by the method of claim 15. This is a product-by-process-style claim. Its practical value depends on claim construction and whether the finished dosage form can be shown to have been made through the recited process. A competitor using a different encapsulation process may have a stronger noninfringement position under claims 15 and 16, but process changes do not necessarily avoid the composition claims.

Rotary-die encapsulation is a standard softgel manufacturing process. The process limitation is therefore narrower than the formulation claims, but it may be relevant to supplier diligence, manufacturing audits and discovery in litigation.

What is the technical rationale for the lactic acid and PEG system?

Naproxen sodium is more water soluble than naproxen, but high drug loading can create precipitation, crystallization and fill-uniformity problems in liquid dosage forms. The claimed formulation uses:

Lactic acid to modify the chemical environment and maintain the drug in a solubilized state;
PEG, particularly PEG 600, as the principal liquid vehicle;
PVP as a polymeric solubilizer and crystallization inhibitor; and
Propylene glycol as a co-solvent and solubilizer.

The claim set therefore protects a formulation architecture rather than a single excipient. Removing one element can avoid a literal claim, but substitution may create equivalent-ingredient or formulation-performance issues. The most significant technical design-around opportunities are changing the acid system, replacing PEG 600, using a non-PVP/nonpropylene glycol solubilizer, reducing naproxen concentration, or using a non-softgel dosage form.

How strong is the patent estate for naproxen softgels?

Based on the supplied claims, US 9,693,979 has moderate formulation strength and narrower platform breadth.

Strengths

Multiple independent composition claims.
Coverage of both broad and narrowly quantified formulations.
Protection for PEG generally in claim 1 and PEG 600 specifically in claims 8 and 17.
Coverage of PVP alone, propylene glycol alone, or both.
Separate process and dosage-form claims.
Dependent claims addressing pH, capsule-shell composition and a specific excipient ratio.

Limitations

Every composition claim requires a soft gelatin capsule.
The composition claims require lactic acid at approximately 5%.
Claims 8 and 17 require approximately 25% naproxen sodium.
Claims 8 and 17 require PEG 600, not merely any PEG.
The claims do not broadly cover tablets, hard capsules, suspensions, transdermal products or injectable products.
The claims do not cover naproxen free acid unless it is treated as meeting the claimed naproxen sodium limitation, which would be a substantial issue.
The claims do not expressly cover every acidifier, every co-solvent or every solubilizer.

The estate is strongest against a directly copied softgel formulation. It is weaker against products using different dosage forms or a materially different liquid-fill chemistry.

When does US Patent 9,693,979 lose exclusivity?

The statutory patent term generally runs 20 years from the earliest effective nonprovisional U.S. filing date, subject to patent-term adjustment, patent-term extension and terminal disclaimers under 35 U.S.C. §§ 154 and 156. The issue date alone does not determine expiration. The exact expiration date must be taken from the USPTO patent record and any applicable terminal-disclaimer or term-adjustment information.[1]

The supplied claim text does not identify:

The earliest nonprovisional priority date;
Patent-term adjustment;
Patent-term extension;
Terminal disclaimers; or
Any continuation or divisional relationship affecting term.

Accordingly, an exact expiration date cannot be established from the claims alone. The relevant commercial question is not only when US 9,693,979 expires, but whether related family members contain unexpired formulation, method-of-use, manufacturing or composition claims.

What is the Orange Book status of US 9,693,979?

The Orange Book lists patents submitted by sponsors for approved drug products, including drug-substance, drug-product and method-of-use patents under FDA listing rules.[2] A patent covering an OTC-style naproxen softgel is not automatically an Orange Book patent merely because it claims a pharmaceutical composition.

The patent’s practical Orange Book relevance depends on whether:

A sponsor submitted it for an FDA-approved naproxen sodium softgel;
The listed product corresponds to the claimed formulation;
The patent was timely submitted and accepted for listing; and
The relevant product is approved under an NDA rather than marketed solely under the OTC monograph pathway.

If listed against an NDA product, a generic applicant may need to address the patent through an ANDA certification. If not listed, the patent may still support a conventional infringement action, but it would not ordinarily create an Orange Book Paragraph IV certification obligation.

What Paragraph IV challenges and generic-entry risks exist?

A Paragraph IV challenge would be relevant only if the patent is listed in the Orange Book against an NDA product and an ANDA applicant seeks approval for a product that falls within the listed patent claims. Under the Hatch-Waxman framework, the applicant could allege that the patent is invalid, unenforceable or not infringed.[3]

For this patent, likely challenge points include:

Lack of written description for the full quantitative ranges;
Enablement of all combinations of lactic acid, PEG, PVP and propylene glycol;
Obviousness based on prior naproxen liquid formulations and softgel excipient systems;
Indefiniteness or claim-construction disputes involving "about 5%" and "about 25%";
Obviousness of using PEG 600, PVP and propylene glycol together; and
Noninfringement based on concentration, dosage form, acid system or encapsulation method.

A generic applicant could pursue a formulation design-around by using:

Naproxen rather than naproxen sodium;
A tablet or hard capsule;
A suspension rather than a molecularly solubilized liquid fill;
A different acidifier;
PEG 400 or another vehicle instead of PEG 600;
A solubilizer other than PVP or propylene glycol; or
A naproxen concentration materially outside approximately 25%.

A Paragraph IV strategy would be stronger if the proposed product avoided the independent claims. It would be weaker if it retained the same softgel, 25% naproxen sodium, 5% lactic acid and PEG 600 architecture.

Which companies are challenging US 9,693,979?

The claim information supplied does not establish an identified Paragraph IV filer, ANDA applicant, district-court case, PTAB proceeding or settlement involving US 9,693,979. Litigation and challenge status must be determined from PACER, PTAB records, FDA listing data and the patent’s assignment history.

No challenge party should be inferred from the existence of the patent alone. OTC naproxen products, unlisted softgels and products approved under different NDAs may create commercial competition without producing a Paragraph IV case.

How does US 9,693,979 compare with the broader naproxen patent landscape?

The broader naproxen landscape generally separates into five categories:

Patent category	Relevance to US 9,693,979
Naproxen or naproxen sodium compound patents	Usually older and unlikely to provide current exclusivity
Salt, polymorph or solid-state patents	May affect active-ingredient sourcing and manufacturing
Tablet and immediate-release formulations	Usually do not cover the claimed softgel liquid matrix
Softgel and liquid-fill formulations	Closest competitive patent category
Method-of-use patents	May affect indications or dosing even if formulation claims are avoided

The principal competitive risk is therefore not basic naproxen chemistry. It is overlapping softgel formulation protection, including patents claiming alternative acids, PEG grades, surfactants, precipitation inhibitors, capsule shells or manufacturing conditions.

What revenue exposure does the patent create?

The patent’s revenue exposure depends on whether a commercially important naproxen softgel practices claims 1, 8 or 17. The most relevant diligence questions are:

Which approved or marketed product uses a liquid softgel fill?
Does the fill contain approximately 25% naproxen sodium?
Is lactic acid present at approximately 5%?
Is PEG 600 used within the claimed concentration?
Are PVP or propylene glycol present?
Is the capsule manufactured by rotary die?
Are related patents listed or still enforceable?

A product that uses the claimed formulation could face a launch delay, redesign cost, licensing requirement or infringement exposure. A conventional naproxen tablet business would generally have limited direct exposure to this patent.

Key Takeaways

US 9,693,979 is a formulation and manufacturing patent for naproxen sodium liquid-filled softgels.
Its core formulation uses approximately 25% naproxen sodium, approximately 5% lactic acid, PEG 600 and PVP, propylene glycol or both.
Claims 1, 8 and 17 provide the principal composition coverage.
Claims 15 and 16 add rotary-die encapsulation and the resulting oral dosage form.
The patent does not broadly cover all naproxen products or all liquid formulations.
The most credible design-arounds change the dosage form, acid system, PEG grade, solubilizer system or drug concentration.
Orange Book and Paragraph IV consequences depend on product-specific listing and approval status.
An exact expiration date cannot be derived from the supplied claim language alone.
Commercial risk is highest for a directly copied naproxen sodium softgel formulation.

FAQs About US Patent 9,693,979

Does US Patent 9,693,979 cover Aleve tablets?

No. The supplied claims require a soft gelatin capsule containing a liquid matrix. Conventional tablets do not satisfy that dosage-form limitation.

Can a naproxen softgel avoid the patent by omitting lactic acid?

Potentially. Lactic acid at approximately 5% is required by the independent composition claims. The effect depends on whether other claims in the patent family or related patents cover the replacement formulation.

Does using PEG 400 instead of PEG 600 avoid infringement?

It may avoid claims 8 and 17, which specifically require PEG 600. It would not necessarily avoid claim 1, which broadly requires one or more polyethylene glycols.

Is US 9,693,979 a patent on naproxen sodium itself?

No. The supplied claims cover a dosage-form and formulation combination. They do not claim naproxen sodium as a compound in isolation.

Can a competitor use the same formulation in a hard capsule?

A hard capsule would not literally meet the soft gelatin capsule limitation in the supplied composition claims. The competitor would still need to assess other patents, equivalents and process claims.

References

United States Patent and Trademark Office. (2024). Patent term adjustment and patent term extension provisions. U.S. Department of Commerce.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. U.S. Department of Health and Human Services.
United States Congress. (1984). Drug Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417, 98 Stat. 1585.
United States Code. (2024). 35 U.S.C. §§ 154, 156, 271 and 282. Office of the Law Revision Counsel.
United States Patent and Trademark Office. (2017). U.S. Patent No. 9,693,979.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Bionpharma	NAPROXEN SODIUM	naproxen sodium	CAPSULE;ORAL	021920-001	Feb 17, 2006		OTC	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

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	2600023	⤷ Start Trial
China	101166520	⤷ Start Trial
China	102940887	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,693,979

Which drugs does patent 9,693,979 protect, and when does it expire?

Summary for Patent: 9,693,979