US Patent 9,351,984: NSAID-in-Oil Phospholipid Formulations, Claim Scope, Patent Strength, and Generic Risk

US Patent 9,351,984 protects pharmaceutical compositions and manufacturing methods that combine a powdered non-steroidal anti-inflammatory drug, or NSAID, with a phospholipid-containing oil carrier. The central commercial concept is a lecithin or phosphatidylcholine oil suspension intended to reduce gastrointestinal toxicity compared with the unformulated NSAID.

The patent is potentially important for phospholipid-associated NSAID products, including aspirin products using phosphatidylcholine-based delivery technology. Its broadest claims cover three categories: methods of making the suspension, the suspension itself, and compositions defined by the process used to manufacture them. The principal validity and infringement issues are the functional gastrointestinal-toxicity limitation, the breadth of the NSAID and oil definitions, the meaning of "associated with the phospholipid," and the extent to which product-by-process claim 19 can be enforced against independently manufactured products.

What does US Patent 9,351,984 cover?

The patent covers an NSAID-in-oil suspension containing:

An NSAID in powder form;
An oil-based carrier;
A phospholipid, including lecithin or phosphatidylcholine;
A therapeutically effective amount of NSAID; and
A reduction in gastrointestinal toxicity relative to the NSAID alone.

The independent claims divide the protection as follows:

Claim	Claim type	Core subject matter
1	Manufacturing method	Admixing powdered NSAID into a phospholipid and biocompatible oil carrier
12	Composition	NSAID-in-oil suspension using lecithin oil and 20-80 wt.% phospholipids
19	Product-by-process composition	Composition produced by admixing powdered NSAID into lecithin oil
2-11	Dependent method claims	Phospholipid, oil, ratio, NSAID class, and association limitations
13-18	Dependent composition claims	Phospholipid, NSAID, ratio, and association limitations
20-26	Dependent product-by-process claims	Phospholipid, oil, NSAID, ratio, and association limitations

The patent therefore does not claim only aspirin. It claims a platform applicable to multiple NSAID classes, including ibuprofen, naproxen, diclofenac, ketoprofen, indomethacin, celecoxib, acetaminophen, and other listed compounds.

What are the broadest independent claims?

Claim 1: method of manufacture

Claim 1 requires a process in which a powdered NSAID is admixed into an oil-based carrier. The carrier must contain both:

A phospholipid; and
A biocompatible oil.

The resulting suspension must contain a therapeutically effective amount of the NSAID and have reduced gastrointestinal toxicity relative to the NSAID alone.

This claim is broad because it does not limit the NSAID to aspirin, does not require a particular dosage form, and does not require a specific phospholipid concentration. It can potentially reach suspensions made with a wide range of listed NSAIDs and vegetable-derived oils.

The claim does require the accused manufacturer to perform the claimed admixing process. A finished product that contains the same ingredients may not infringe claim 1 if it was made through a materially different process, although process evidence may be available through batch records, manufacturing specifications, technical documents, or discovery.

Claim 12: composition

Claim 12 is the principal composition claim. It requires:

An NSAID in powder form;
Lecithin oil;
Approximately 20-80 wt.% phospholipids;
A therapeutically effective amount; and
Reduced GI toxicity relative to the NSAID alone.

Unlike claim 1, claim 12 is directed to the product rather than the manufacturing step. This makes it more significant for finished-product enforcement. A generic or competing product could face infringement risk even if its manufacturing process is not known, provided the composition satisfies the structural and functional limitations.

The requirement for "lecithin oil" may narrow the claim compared with a formulation using a non-lecithin phospholipid system. The specification and prosecution history would determine whether "lecithin oil" is construed broadly to include purified phosphatidylcholine oils, mixed phospholipid oils, or only a defined lecithin-based carrier.

Claim 19: product-by-process composition

Claim 19 covers a composition that is the product of a process involving:

Powdered NSAID;
Admixing into an oil-based carrier;
Lecithin oil;
20-80 wt.% phospholipids;
Therapeutically effective NSAID; and
Reduced GI toxicity.

Product-by-process claims generally present a complex enforcement structure. In validity analysis, the product limitations may be considered independently of the process in some circumstances. In infringement analysis, the accused product generally must satisfy the claimed product characteristics and be made by the recited process or an equivalent process, depending on the governing interpretation and prosecution history.

Claim 19 is therefore useful as a fallback claim but is less commercially clean than a conventional composition claim.

How broad is the NSAID coverage?

Claims 3, 4, 14, 15, 21, and 22 define the NSAID universe broadly.

The listed classes include:

Propionic acid drugs;
Acetic acid drugs;
Ketone drugs;
Fenamate drugs;
Oxicam drugs;
Salicylic acid drugs;
Pyrazolin acid drugs;
Acetaminophen; and
COX-2 inhibitors.

The named compounds include aspirin, ibuprofen, naproxen, diclofenac, ketorolac, indomethacin, piroxicam, celecoxib, rofecoxib, and others.

This breadth creates two opposing effects.

First, the claims have broad platform value. A product developer may not avoid the patent merely by selecting a different conventional NSAID. A formulation using ibuprofen instead of aspirin could remain within the claim set.

Second, the breadth increases potential validity pressure. A challenger could argue that the prior art disclosed phospholipid-associated drug formulations, oil suspensions, or GI-protective NSAID systems before the patent's effective filing date. The challenger would then focus on whether the prior art taught the claimed combination, concentration range, powder-addition process, and reduced GI toxicity.

What formulations and excipients are protected?

Phospholipid concentration

The claims include several overlapping ranges:

Claim	Phospholipid limitation
2	About 20-80 wt.%
9	About 20-60 wt.%
10	About 20-40 wt.% phosphatidylcholine
12	About 20-80 wt.%
13	About 20-80 wt.%
19	About 20-80 wt.%
20	About 20-60 wt.%

The 20-80 wt.% range is the principal concentration limitation. Claims 9 and 20 provide narrower positions at 20-60 wt.%, while claim 10 narrows the carrier to 20-40 wt.% phosphatidylcholine.

A formulation containing less than approximately 20 wt.% phospholipid may fall outside the literal scope of the principal claims, subject to claim construction and the doctrine of equivalents. A formulation containing more than approximately 80 wt.% may also avoid the literal range, although the specification and prosecution history would be relevant to any equivalents analysis.

Biocompatible oils

Claims 5, 6, and 23 identify a wide oil group:

Vegetable oils;
Hydrogenated vegetable oils;
Peanut oil;
Canola oil;
Avocado oil;
Safflower oil;
Olive oil;
Corn oil;
Soybean oil;
Sesame oil; and
Vitamins A, D, and E.

The claim set does not require a particular oil-to-phospholipid ratio. This gives the patent coverage across multiple pharmaceutically acceptable lipid vehicles, provided the carrier qualifies as an oil-based carrier and contains the required phospholipid content.

What does "reduced gastrointestinal toxicity" require?

The GI-toxicity limitation is central to both validity and infringement.

The claims do not specify:

A numerical reduction;
A particular animal model;
A clinical endpoint;
A gastrointestinal lesion score;
A treatment duration;
A comparator dose;
A required percentage reduction; or
A statistical significance threshold.

The phrase therefore creates claim-construction and enablement issues. The patent specification and prosecution record would be important in determining how a court interprets the limitation.

For enforcement, the patent owner would likely rely on comparative testing showing that the claimed suspension causes less gastric damage, ulceration, bleeding, or other GI injury than the corresponding unformulated NSAID. An accused party could challenge infringement by arguing that its formulation does not meet the comparative toxicity limitation or that the patent fails to define a reproducible testing standard.

For validity, a challenger could argue that the term is indefinite if the patent does not provide objective boundaries. The counterargument would be that a person skilled in pharmaceutical development could measure GI toxicity using established animal or clinical assays.

How important is the "NSAID associates with the phospholipid" limitation?

Claims 11, 18, and 26 add an association limitation.

"Association" is broader than covalent bonding and may include adsorption, ion pairing, hydrophobic interaction, molecular association, or incorporation within a phospholipid structure. The precise meaning would depend on the specification and technical evidence.

This limitation can help distinguish a simple physical mixture from a phospholipid-associated NSAID system. It can also create evidentiary problems. The patent owner may need analytical data such as:

Differential scanning calorimetry;
X-ray diffraction;
Spectroscopy;
Particle-size analysis;
Dissolution testing;
Solid-state characterization; or
Separation and partitioning studies.

The supplied claim set contains a drafting defect in claim 18, which refers to "the composition of claim 11," even though claim 11 is a method claim. That dependency may support an indefiniteness or formal-claim challenge, although courts often examine whether the intended dependency is clear from the overall patent.

How does the patent compare with conventional NSAID products?

Product type	Likely position relative to US 9,351,984
Conventional aspirin tablet	Generally outside the claimed oil-suspension structure
Conventional ibuprofen tablet	Generally outside unless it contains the claimed phospholipid oil system
Liquid NSAID in non-phospholipid oil	Potentially outside the literal claims
NSAID in lecithin oil with less than 20 wt.% phospholipid	Potential literal-coverage issue
NSAID powder admixed into phospholipid oil	High relevance to claims 1 and 19
Phosphatidylcholine-associated aspirin suspension	High relevance to claims 12 and 19
Phospholipid formulation using a non-oil aqueous vehicle	Potentially outside the oil-carrier limitation
Lipid formulation containing a different active ingredient	Outside the NSAID limitations unless the active ingredient qualifies as a claimed NSAID

The patent does not broadly monopolize all GI-protective NSAID formulations. It is directed to a specific lipid architecture: powdered NSAID in an oil carrier containing a substantial phospholipid component.

What is the patent's likely strength?

The strongest features are:

Broad NSAID coverage.
Broad vegetable-oil coverage.
Separate method and composition claim categories.
Concentration ranges that cover commercial phospholipid-rich formulations.
Functional coverage based on reduced GI toxicity.
Product-by-process fallback protection.

The principal vulnerabilities are:

Potential prior art involving phospholipid-drug complexes.
Lack of a quantitative GI-toxicity threshold.
Potential ambiguity in "associated with the phospholipid."
Breadth across unrelated NSAIDs and oil systems.
Product-by-process enforcement limits.
Possible written-description and enablement challenges for the full genus.
The defective dependency of claim 18.
Overlap among claims 12 and 13, and among claims 2, 9, and 10.

The patent is stronger against a product that closely replicates a lecithin/phosphatidylcholine oil suspension and makes therapeutic GI-protection claims. It is weaker against a product using a different carrier architecture, a low-phospholipid formulation, a non-oil lipid system, or a manufacturing process that does not admix powdered NSAID into the carrier.

What generic entry risks exist?

A generic or follow-on manufacturer would likely evaluate four launch strategies.

Design-around strategy

The most direct design-around options are:

Use an aqueous or solid lipid carrier rather than an oil-based carrier;
Use less than 20 wt.% phospholipid;
Use a non-lecithin lipid system;
Avoid phosphatidylcholine;
Use a different particle or encapsulation architecture;
Use a conventional tablet, capsule, or suspension; or
Use an NSAID formulation without evidence of reduced GI toxicity.

Paragraph IV challenge

A Paragraph IV certification could target:

Anticipation by earlier phospholipid-NSAID formulations;
Obviousness based on combining known NSAIDs with lecithin or phosphatidylcholine oils;
Indefiniteness of "reduced GI toxicity";
Lack of enablement across all listed NSAIDs and oils;
Lack of written description for the full genus;
Failure of a product-by-process limitation; and
Improper or unsupported Orange Book listing.

The most credible invalidity theory would likely combine prior-art references showing NSAID phospholipid association with references showing oil-based pharmaceutical carriers and GI-protective lipid delivery.

ANDA litigation

If the patent is listed in the Orange Book for a relevant approved product, an ANDA containing a Paragraph IV certification could trigger a Hatch-Waxman suit under 35 U.S.C. § 271(e)(2). The resulting case would focus on the proposed product, not merely the commercial concept.

A generic applicant would need to analyze its formulation composition, excipient concentrations, manufacturing batch process, dissolution profile, and any comparative GI data. The composition claims create greater risk than the process claims because the patent owner may not need to prove the exact manufacturing route for every infringement theory.

What is the Orange Book status of US Patent 9,351,984?

Patent listing is product-specific. A patent number does not automatically receive Orange Book protection merely because it covers a pharmaceutical formulation.

For a relevant approved product, the FDA Orange Book record should be reviewed for:

NDA number;
Active ingredient;
Dosage form;
Strength;
Patent number;
Patent expiration date;
Use code;
Delisting status; and
Pediatric-exclusivity adjustments.

The patent's method claims may be listed only if they correspond to an approved method of use under FDA listing rules. Composition claims are more likely to be relevant to a listed drug product if the approved product falls within the claimed formulation.

The FDA Orange Book, USPTO Patent Center, and the patent's maintenance-fee record should be read together before relying on a current exclusivity date.[1][2]

What is the commercial and competitive significance?

The patent is most relevant to products positioned as GI-safer NSAID formulations rather than ordinary low-cost NSAID tablets. Its commercial value depends on whether the formulation can demonstrate a clinically meaningful reduction in GI injury while preserving NSAID efficacy, stability, manufacturability, and bioavailability.

Potential competitors include:

Conventional generic aspirin and NSAID manufacturers;
Phospholipid-associated NSAID developers;
Lipid-based drug-delivery companies;
Branded NSAID manufacturers;
Consumer-health companies with OTC aspirin portfolios; and
Developers of enteric-coated, buffered, or gastroprotective NSAID products.

The patent does not block all competing GI-risk reduction technologies. Proton-pump inhibitor combinations, enteric coatings, buffered tablets, prodrugs, selective COX-2 inhibitors, and non-phospholipid lipid systems can compete without necessarily practicing the claimed invention.

What licensing and litigation issues should be reviewed?

The key commercial documents are:

Patent assignment history;
Continuation and divisional applications;
Patent-term-adjustment calculation;
Terminal disclaimers;
Orange Book listing records;
Any FDA-approved product associated with the formulation;
Paragraph IV notices;
Hatch-Waxman complaints;
Inter partes review petitions;
Post-grant review records;
Settlement agreements; and
License or commercialization agreements involving the patent owner.

The supplied claim set alone does not establish a litigation history, settlement, license, current assignee, or live enforceability status. Those issues require the USPTO, FDA, PACER, PTAB, and SEC records.

Key Takeaways

US Patent 9,351,984 targets NSAID-in-oil suspensions containing substantial phospholipid concentrations.
Claims 1, 12, and 19 are the commercial center of the patent.
The patent reaches numerous NSAIDs, not only aspirin.
Lecithin oil, phosphatidylcholine, vegetable oils, and 20-80 wt.% phospholipid concentrations are central limitations.
The reduced-GI-toxicity limitation is both a source of commercial value and a potential validity vulnerability.
Claim 12 presents the most direct finished-product risk.
Claim 1 creates manufacturing-process risk where powdered NSAID is admixed into the lipid carrier.
Claim 19 provides product-by-process coverage but may be harder to enforce.
Claims 11, 18, and 26 raise proof issues concerning phospholipid association.
Claim 18 contains a dependency defect because it refers to claim 11 as a composition claim.
A credible design-around would change the carrier architecture, phospholipid concentration, manufacturing process, or dosage-form structure.
Orange Book status, expiration, litigation, and licensing cannot be determined from the claim text alone.

FAQs

Does US Patent 9,351,984 cover ordinary aspirin tablets?

No. The claims require an oil-based carrier containing phospholipid, with the principal claims requiring an NSAID-in-oil suspension. A conventional aspirin tablet would generally not satisfy those structural limitations.

Does a formulation with 15% phospholipid infringe the patent?

It may fall outside the literal 20-80 wt.% phospholipid range in the principal claims. The specification, prosecution history, and equivalents analysis would determine whether additional risk remains.

Can a non-lecithin phospholipid formulation avoid the patent?

Possibly. Claims 12 and 19 specifically require lecithin oil, while claim 1 more broadly requires a phospholipid and a biocompatible oil. A non-lecithin formulation must be assessed against the full claim set.

Is reduced GI toxicity required to prove infringement?

Yes, where the asserted claim contains that limitation. The parties would likely dispute the comparator, test method, statistical threshold, and whether the accused product demonstrates the claimed reduction.

Does the patent cover a liquid NSAID formulation made without powdered NSAID?

Claims 1 and 19 expressly refer to NSAID in powder form and an admixing process. A product made from a dissolved, crystalline, granulated, or otherwise non-powder starting material may present a stronger design-around position, subject to claim construction and equivalents.

References

U.S. Patent and Trademark Office. (2016). U.S. Patent No. 9,351,984.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Food and Drug Administration. (n.d.). Approved drug product patent and exclusivity information.
United States Code, 35 U.S.C. § 271(e)(2).
United States Code, 21 U.S.C. § 355(j).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
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Australia	2001297778	⤷ Start Trial
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Details for Patent: 9,351,984

Summary for Patent: 9,351,984