United States Patent 7,320,802: Fenofibrate Nanoparticle Claims, Expiration, and Patent Landscape

United States Patent 7,320,802 covers methods of treating lipid disorders with nanoparticulate fenofibrate formulations designed to reduce food-effect variability. The claims require more than fenofibrate alone: they combine particle-size limitations, surface stabilization, redispersion in biorelevant media, and human pharmacokinetic bioequivalence between fed and fasted administration. The patent’s nominal 20-year term ran from the April 1, 2004 nonprovisional filing date to April 1, 2024. The patent therefore does not provide a current United States exclusivity barrier unless a recorded patent-term adjustment or other enforceable continuation right changes that conclusion. [1][2]

What drug and formulation does US Patent 7,320,802 protect?

The claimed active ingredient is fenofibrate, identified chemically as 2-[4-(4-chlorobenzoyl)phenoxy]-2-methylpropanoic acid, 1-methylethyl ester. Fenofibrate is a peroxisome proliferator-activated receptor alpha agonist used for hypertriglyceridemia and mixed dyslipidemia.

The patent is directed to a nanocrystalline or nanoparticulate formulation rather than to the fenofibrate molecule itself. Its technical objective is to improve dissolution and absorption and reduce the food effect associated with conventional micronized fenofibrate products.

The core formulation concept has four elements:

Required element	Claim significance
Fenofibrate particles	The claims are limited to fenofibrate or a salt thereof
Submicron particle size	D50, mean, or D90 thresholds define the nanoparticulate formulation
Surface stabilizer	Stabilizes particles and limits aggregation
Fed/fasted bioequivalence	Requires AUC and Cmax 90% confidence intervals within 0.80 to 1.25

The claims also require that the particles redisperse in a biorelevant medium. A formulation that is nanosized before administration but agglomerates into materially larger particles after exposure to gastrointestinal conditions presents a substantial claim-scope issue.

How many independent claim groups does US 7,320,802 contain?

The 396 claims are organized around six independent claim groups: claims 1, 55, 109, 163, 217, and 271.

Independent claim	Principal particle limitation	Character
1	D50 less than 500 nm	Broadest sub-500 nm group
55	Mean particle size less than 500 nm	Alternative statistical measurement
109	D90 less than 700 nm	Broader upper-tail distribution
163	D50 about 500 nm	Approximate-size group
217	Mean particle size about 500 nm	Approximate mean-size group
271	D90 about 700 nm	Approximate D90 group

Each independent claim group requires substantially the same commercial and pharmacokinetic architecture:

Treatment of a listed lipid-related condition.
Administration of an effective amount of a fenofibrate composition.
Surface-stabilized particles.
Redispersion in biorelevant media.
Fed/fasted bioequivalence.
A 90% confidence interval of 0.80 to 1.25 for both AUC and Cmax.

The six groups are largely parallel. The patent’s large claim count results mainly from repetitive dependent claims rather than from six materially different inventions.

What conditions and therapeutic uses are covered?

The independent claims recite:

Hypercholesterolemia
Hypertriglyceridemia
Coronary heart disease
Cardiovascular disorders
Peripheral vascular disease
Symptomatic carotid artery disease
Mixed dyslipidemia
Increased risk of pancreatitis

Dependent claims further identify use as adjunctive therapy to diet for reducing LDL-C, total cholesterol, triglycerides, or Apo B. Claims 47-50 and corresponding claims in the later groups connect the formulation to commercial fenofibrate labeling concepts, including hypertriglyceridemia and pancreatitis-risk reduction.

The therapeutic indication language is broad, but it does not independently define the commercial product. A product must satisfy the formulation and pharmacokinetic limitations in the applicable independent claim.

What particle-size limitations are protected?

The patent uses several particle-size metrics:

Metric	Representative limitations
D50	Less than 500, 400, 350, 300, 250, 200, 150, 100, 75, or 50 nm
Mean size	Less than 500 or 100 nm, or approximately 500 or 100 nm
D90	Less than or approximately 700 nm, with dependent values down to 50 nm
D99	Less than or approximately 500 nm

The most commercially important claim scope is the sub-500 nm D50 and mean-size coverage in claims 1 and 55 and their dependents. The D90-based claims can cover a formulation with a comparatively broad particle-size distribution, provided the D90 remains within the claimed boundary.

Particle-size infringement would likely depend on:

The analytical method used.
Whether the measurement is made before or after redispersion.
The definition of D50, D90, or mean size.
The sampling protocol.
Whether the formulation is evaluated in its finished dosage form or as a bulk suspension.
Whether “about” is construed as a numerical range supported by the specification.

A generic or follow-on developer would need particle-size testing using a validated method aligned with the patent specification and regulatory product characterization methods.

What pharmacokinetic limitations are required?

The fed/fasted bioequivalence limitation is the principal narrowing feature of the claims. The claimed formulation must be bioequivalent when administered in a fasted state and a fed state, with both parameters meeting the conventional bioequivalence interval:

Pharmacokinetic parameter	Required 90% confidence interval
AUC	0.80 to 1.25
Cmax	0.80 to 1.25

Dependent claims also recite:

AUC differences between fed and fasted administration of less than 35%, 30%, 25%, 20%, 15%, 10%, 5%, or 3%.
AUC of approximately 139 μg/mL·h at a 160 mg dose.
Earlier Tmax than conventional micronized 160 mg tablets or 200 mg capsules.
Specified fenofibric acid blood concentrations at one, two, three, four, five, and 24 hours.
Bioequivalence to conventional micronized 54 mg, 160 mg, and 200 mg dosage forms.

These limitations create an important distinction between formulation similarity and claim infringement. A product can contain submicron fenofibrate particles and still avoid a claim if it does not demonstrate the required fed/fasted pharmacokinetic profile. Conversely, the claims may reach different excipient systems if the finished product satisfies the particle, redispersion, and pharmacokinetic limitations.

What formulations are protected by US 7,320,802?

The patent expressly covers a wide range of dosage forms and administration routes, including:

Tablets
Capsules
Oral suspensions
Liquid dispersions
Gels
Aerosols
Controlled-release products
Immediate-release products
Delayed-release products
Extended-release products
Fast-melt products
Lyophilized products
Mixed immediate-release and controlled-release products

The commercially relevant scope is concentrated in oral tablets and capsules. The claims also recite pulmonary, rectal, ophthalmic, colonic, parenteral, buccal, nasal, topical, and other routes, but those alternatives appear primarily to maximize claim breadth rather than to define the marketed fenofibrate product.

Which surface stabilizers are covered?

Claim 53 and corresponding claims recite an extensive list of stabilizers, including:

Hypromellose
Dioctyl sodium sulfosuccinate
Sodium lauryl sulfate
Poloxamers
Poloxamines
Polyvinylpyrrolidone
Hydroxypropyl cellulose
Carboxymethylcellulose
Polyethylene glycols
Phospholipids
Gelatin
Casein
Ionic and nonionic surfactants
Cationic polymers and quaternary ammonium compounds

Claim 54 narrows the formulation to hypromellose, dioctyl sodium sulfosuccinate, and sodium lauryl sulfate. This excipient combination is more technically specific and may be more valuable for product-specific enforcement than the extensive Markush-style stabilizer list in claim 53.

What dissolution performance is claimed?

Claims 36-40 and their parallel claims establish dissolution thresholds in an aqueous medium containing 0.025 M sodium lauryl sulfate, using the European Pharmacopoeia rotating-blade method.

The most stringent dissolution profile requires:

Time point	Dissolved amount
Five minutes	At least 40%
Ten minutes	At least 80%
Twenty minutes	At least 100%

Other claims cover lower thresholds, including:

At least 20%, 30%, or 40% at five minutes.
At least 40%, 50%, 60%, 70%, or 80% at ten minutes.
At least 70%, 80%, 90%, or 100% at 20 minutes.

The dissolution claims provide a potentially useful screening framework for freedom-to-operate analysis. They also create testing sensitivity because results may vary with surfactant concentration, apparatus configuration, agitation rate, sampling correction, particle aggregation, and analytical endpoint.

When did US Patent 7,320,802 lose exclusivity?

The patent issued on January 22, 2008. Its application filing date was April 1, 2004, and the standard patent term therefore ran to April 1, 2024, subject to any patent-term adjustment recorded by the USPTO. [1][2]

Event	Date
Nonprovisional filing	April 1, 2004
Patent issuance	January 22, 2008
Standard 20-year term endpoint	April 1, 2024

Patent 7,320,802 is not a biologic patent and has no biosimilar exclusivity implications. It is a small-molecule formulation patent. FDA exclusivity, if any, is separate from patent term and depends on the relevant NDA and approval history.

What is the FDA and Orange Book status?

The patent is associated with nanoparticulate fenofibrate products, particularly Fenoglide-type formulations. Fenoglide is an oral fenofibrate product developed around a nanoparticulate formulation intended to reduce food-effect variability.

The FDA Orange Book must be reviewed at the NDA level because listing status can change through patent delisting, product discontinuation, transfer of ownership, or expiration. Orange Book listing does not extend the patent term and does not establish validity or infringement. [3]

The relevant regulatory issues are:

Whether the reference listed drug remains active.
Whether US 7,320,802 remains listed for the approved product.
Whether the listing carries a use code or formulation-related description.
Whether an ANDA applicant submitted a Paragraph IV certification.
Whether any 30-month stay, litigation, settlement, or launch agreement remains operative.

Which companies challenged the patent, and what litigation affects it?

The supplied claim text does not establish a complete litigation or settlement history. Patent-number analysis alone cannot identify every ANDA challenge, because Paragraph IV litigation may be filed against the NDA holder or an exclusive licensee and may involve related patents rather than US 7,320,802 itself.

A current diligence review should distinguish:

Litigation naming US 7,320,802 directly.
Litigation concerning the same Fenoglide NDA but different patents.
Paragraph IV notices that did not result in litigation.
Declaratory-judgment actions.
Settlements with authorized generic or launch provisions.
Cases dismissed after patent expiration or product discontinuation.

For commercial purposes, the April 2024 nominal expiration materially reduces the value of any unresolved Paragraph IV dispute involving this patent alone. Later-issued continuation, formulation, manufacturing, or crystalline-form patents would require separate analysis.

How strong is the patent estate?

The patent is technically broad but legally concentrated. Its strength depends on proof of the combined limitations rather than on the breadth of the indication list.

Strength factor	Assessment
Active ingredient coverage	Weak as a standalone barrier because fenofibrate is old and broadly generic
Particle-size coverage	Moderate; multiple statistical definitions create alternative theories
Excipient coverage	Broad but vulnerable to written-description, enablement, and construction challenges
Fed/fasted PK limitation	Strong screening limitation but costly to prove
Dissolution limitations	Useful for product comparison, with method-dependent outcomes
Method-of-treatment format	Requires proof of administration and therapeutic use
Claim redundancy	Provides fallback positions but adds little independent inventive scope
Current term	Nominally expired in 2024

The patent’s commercial value was strongest before expiration, when a nanoparticulate fenofibrate product could use its food-effect profile and lower dose as a differentiation strategy. Its residual value now lies mainly in historical enforcement, litigation analysis, prosecution history, and comparison with later patent families.

What generic entry risks exist?

A generic fenofibrate developer would face three principal historical risks:

A formulation could fall within the particle-size and stabilizer limitations.
Fed and fasted pharmacokinetic testing could satisfy the claimed 0.80-1.25 intervals.
Dissolution and redispersion data could align with the claimed thresholds.

Current entry risk from US 7,320,802 alone is limited by the nominal expiration date. The more important current barriers are likely to be:

Later formulation patents.
Product-specific regulatory exclusivity.
Manufacturing know-how.
Scale-up of wet milling or high-energy particle-reduction processes.
Stabilizer adsorption and aggregation control.
Tablet compression and content-uniformity requirements.
Demonstration of equivalent fenofibric acid exposure.
Any remaining active patents listed against the reference product.

How does this patent compare with conventional micronized fenofibrate patents?

Conventional fenofibrate patents generally focus on:

Micronization.
Improved dissolution.
Tablet or capsule composition.
Dosage strength.
Chemical forms.
Therapeutic combinations.

US 7,320,802 is differentiated by combining nanoscale particle engineering with a clinical pharmacokinetic outcome. The patent does not merely claim a smaller particle. It claims a formulation that maintains nanoscale dispersion and produces substantially food-independent exposure.

That combination made the patent more product-specific than a conventional micronization patent, but it also increased the evidentiary burden for infringement.

Key Takeaways

US 7,320,802 is a fenofibrate nanoparticle formulation patent, not a basic compound patent.
The six independent claim groups use D50, mean-size, and D90 particle limitations.
Every independent claim requires surface stabilization, redispersion in biorelevant media, and fed/fasted bioequivalence.
The most specific commercial formulation is associated with hypromellose, dioctyl sodium sulfosuccinate, and sodium lauryl sulfate.
The claims cover tablets, capsules, suspensions, and other dosage forms, but oral solid products are commercially central.
The standard patent term ran to April 1, 2024, subject to USPTO-recorded patent-term adjustment.
The patent is a small-molecule formulation patent and has no biosimilar relevance.
Current commercial risk should focus on later fenofibrate patents, NDA listing status, and manufacturing barriers rather than on this patent alone.
The claim set is broad in form but depends on tightly linked analytical and pharmacokinetic requirements.

FAQs

Does US 7,320,802 cover all fenofibrate products?

No. It covers specified methods using surface-stabilized fenofibrate particles that satisfy particle-size, redispersion, and fed/fasted pharmacokinetic limitations.

Does a 160 mg fenofibrate tablet necessarily infringe the patent?

No. Dose alone is insufficient. Infringement would depend on the formulation, particle-size distribution, stabilizer system, redispersion behavior, pharmacokinetic profile, and applicable claim construction.

Are fenofibrate nanoparticles protected by a biosimilar pathway?

No. Fenofibrate is a small molecule regulated through the ANDA pathway, not the biosimilar pathway under the Public Health Service Act.

Can a generic avoid the patent by using micronized rather than nanoparticulate fenofibrate?

Potentially, but the product would still require a full claim comparison. A micronized product that does not meet the claimed particle-size or redispersion limitations would have a stronger noninfringement position under those limitations.

Is the patent still an Orange Book barrier after 2024?

The patent’s standard term ended in 2024. Any remaining regulatory or litigation significance depends on the recorded USPTO term, current Orange Book listing, related patents, and applicable settlement or exclusivity rights.

References

United States Patent and Trademark Office. (2008). U.S. Patent No. 7,320,802, Nanoparticulate fenofibrate formulations.
United States Code, 35 U.S.C. § 154. Patent term and adjustment provisions.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	040110	⤷ Start Trial
Argentina	072134	⤷ Start Trial
Argentina	072135	⤷ Start Trial
Argentina	111501	⤷ Start Trial
Austria	293959	⤷ Start Trial
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Details for Patent: 7,320,802

Summary for Patent: 7,320,802