US Patent 7,037,529: Fenofibrate Granulate Claims, Expiration, Litigation Risk and Patent Landscape

US Patent 7,037,529 protects a specific immediate-release fenofibrate formulation platform based on micronized fenofibrate deposited with hydrophilic polymer onto soluble carrier particles. The claims combine structural limitations with a dissolution-performance requirement. The patent issued May 2, 2006, and appears to have reached the end of its ordinary 20-year term from the earliest claimed priority date in November 2021, subject to any patent-term adjustment recorded in the USPTO file. It should be treated as an expired patent for current US freedom-to-operate analysis unless the official patent record shows an unusual term adjustment or related enforceable continuation.

The commercial risk historically centered on products using lactose or another soluble carrier, polyvinylpyrrolidone or a related polymer, micronized fenofibrate, fluidized-bed coating, and rapid dissolution. The patent does not broadly cover every fenofibrate tablet, every micronized fenofibrate product, or every formulation achieving rapid dissolution.

What does US Patent 7,037,529 protect?

The patent protects three principal categories:

Fenofibrate compositions containing coated carrier particles.
Fenofibrate granules or layers deposited on carrier particles.
Processes for manufacturing those granules by spraying a fenofibrate-polymer suspension onto carrier particles.

The central technical combination is:

Micronized fenofibrate.
An inert or otherwise defined carrier particle.
At least one hydrophilic polymer.
Coating or deposition of the fenofibrate-polymer mixture onto the carrier.
Dissolution of at least 75% within 30 minutes under specified European Pharmacopoeia rotating-blade conditions.

The strongest commercial embodiments appear to be lactose carrier particles coated with micronized fenofibrate and polyvinylpyrrolidone, followed by tableting.

Core claim architecture

Claim group	Principal subject matter	Key limitations
Claims 1-26	Composition	Coated inert carrier particles, micronized fenofibrate, hydrophilic polymer, at least 75% dissolution
Claims 27-29	Manufacturing process	Suspension preparation, spraying onto carrier particles, optional coating and compression
Claims 30-45	Layered granule composition	One or more deposited layers containing fenofibrate and hydrophilic polymer
Claims 46-69	Alternative composition family	Carrier particle size, weight ratio, dissolution and excipient limitations
Claims 70-71	Narrow manufacturing process	Fluidized-bed granulation using 100-400 micron carrier particles
Claims 72-84	Particle-size and polymer-state limitations	Fenofibrate particle size of 20 or 10 microns; polymer dissolving, gelling or suspending
Claims 85-90	Higher dissolution-performance claims	At least 95.5%, 95.9%, or 95.9% +/- 2.1% dissolution at 30 minutes

How broad are the independent composition claims?

The principal independent claims are claims 1, 30, 46, 85, 86, 87, 88, 89 and 90. Their scope is narrower than the number of claims suggests because the claims repeat several mandatory limitations.

Claim 1

Claim 1 requires:

A fenofibrate composition.
Granulates.
Inert carrier particles.
A coating containing an admixture of hydrophilic polymer and micronized fenofibrate.
At least 75% dissolution within 30 minutes.
A specified rotating-blade method at 75 rpm.
One of two specified dissolution media.

A product that contains micronized fenofibrate but lacks coated carrier particles would not literally satisfy claim 1. A conventional wet-granulated tablet, a solid dispersion without carrier particles, or a soft gelatin capsule would generally fall outside the literal language unless its structure is equivalent under the doctrine of equivalents.

Claim 30

Claim 30 uses a layered formulation structure:

Carrier particles.
One or more layers.
Each layer contains an admixture of micronized fenofibrate and hydrophilic polymer.
The layer is deposited on the carrier particles.
The formulation achieves the specified dissolution.

This claim is potentially broader than claim 1 in its use of “carrier particles” rather than expressly requiring “inert” carrier particles. It remains dependent on a deposited-layer architecture and the dissolution limitation.

Claim 46

Claim 46 adds numerical restrictions to the formulation:

Carrier-particle size from 50 to 500 microns.
Micronized fenofibrate-to-polymer weight ratio from 1:10 to 4:1.
At least 75% dissolution within 30 minutes.

The claim is commercially important because it captures the likely operating window for fluidized-bed coated granules while excluding formulations outside the stated particle-size and ratio ranges.

Claims 85-90

Claims 85 through 90 raise the dissolution threshold to approximately 95.5% or 95.9% at 30 minutes. These claims are not simply broad performance claims. They retain the underlying coated-particle or layered-granule architecture.

A product achieving 96% dissolution but using uncoated granules would not necessarily infringe claims 85-90. Conversely, a product with the required structure that reaches only 80% dissolution could infringe claims 1, 30 or 46 but not the higher-performance claims.

What formulation features are protected?

The dependent claims create a dense but predictable formulation matrix.

Carrier particles

Claims 3, 4, 5, 6, 19, 32, 44, 47, 48, 58 and 59 address the carrier.

Protected or expressly claimed materials include:

Lactose.
Saccharose.
Hydrolyzed starch.
Mixtures of these materials.
Hydrosoluble carriers.
Particle sizes from 50 to 500 microns.
Narrower particle sizes from 100 to 400 microns.

Lactose is the most commercially significant carrier limitation. A formulation using insoluble microcrystalline cellulose, calcium phosphate or a polymeric pellet may avoid several dependent claims, although it could remain within a broader independent claim if the carrier satisfies the independent limitations.

Hydrophilic polymers

Claims 10, 20, 33, 50 and 60 expressly identify:

Polyvinylpyrrolidone.
Polyvinyl alcohol.
Hydroxypropylcellulose.
Hydroxymethylcellulose.
Hydroxypropylmethylcellulose.
Gelatin.
Mixtures of two or more hydrophilic polymers.

Polyvinylpyrrolidone is specifically claimed in several dependent claims and is likely the most important polymer for product comparison. Use of a nonlisted hydrophilic polymer may avoid the dependent claims but will not necessarily avoid the independent claims, which recite “at least one hydrophilic polymer” without limiting the polymer to the listed materials.

Fenofibrate particle size

Claims 17, 18, 57, 72, 73 and 74 recite:

Fenofibrate particle size of 20 microns or less.
A narrower size of 10 microns or less.

The independent claims generally require “micronized” fenofibrate but do not always specify a numerical particle size. A product using micronized fenofibrate larger than 20 microns may avoid the numerical dependent claims while remaining exposed under an independent claim if it meets the other limitations.

Surfactants

Claims 21-24, 38-41 and 61-64 cover surfactants including:

Sodium lauryl sulfate.
Polysorbates.
Sodium dioctylsulfosuccinate.
Lecithin.
Alcohol-based surfactants.
Polyoxyethylene derivatives.
Poloxamers.

The stated concentration ranges include:

0.1% to 10% by weight.
0.1% to 3% by weight in certain claim families.

Surfactant selection is not central to every independent claim. A formulation without surfactant may still infringe the core claims.

What dissolution test must an accused product satisfy?

The dissolution limitation is unusually important because it is part of the independent claims rather than merely a preferred result in the specification.

The claims require at least:

75% dissolution at 30 minutes in claims 1, 30 and 46.
95.9% in claim 85.
95.5% in claim 86.
95.9% in claim 87.
95.9% +/- 2.1% in claims 88-90.

The test conditions include:

Rotating-blade method.
75 rpm.
European Pharmacopoeia method.
Water containing 2% by weight polysorbate 80, or 0.025 M sodium lauryl sulfate.

The exact test medium matters. Dissolution data generated under USP apparatus 2 conditions using a different surfactant concentration, pH, volume or agitation rate may not establish literal satisfaction or noninfringement. A freedom-to-operate program should test the proposed product under each recited medium and preserve particle-size, polymer-ratio and batch-process data.

How do the process claims affect infringement risk?

Claims 27-29 and 70-71 cover manufacturing methods rather than the finished product alone.

The core process steps are:

Prepare a suspension of micronized fenofibrate in a hydrophilic-polymer solution.
Optionally include a surfactant.
Spray the suspension onto carrier particles.
Form granules.
Optionally apply an outer coating.
Compress the granules into tablets.

Claim 28 requires a fluidized-bed granulator. Claim 70 narrows the process further by requiring 100-400 micron carrier particles and a fluidized-bed granulator.

A manufacturer could potentially design around these process claims by:

Using dry blending and roller compaction.
Forming a solid dispersion before granulation.
Applying fenofibrate by a different coating technology.
Using extrusion, spray drying or solvent evaporation.
Coating a preformed tablet rather than carrier particles.
Using a non-spraying deposition method.

Process-claim avoidance does not eliminate product-claim exposure. A product made by a different process can still infringe claims 1, 30 or 46 if the finished granules have the claimed structure and dissolution profile.

When did US Patent 7,037,529 lose exclusivity?

Event	Date or period
Earliest claimed priority	November 2000, based on the patent-family record
US patent grant	May 2, 2006
Ordinary 20-year term	Approximately November 2021
Current practical status	Expired under the ordinary term, absent unusual term adjustment
Regulatory exclusivity	Separate from patent term and must be analyzed independently

The patent’s grant date does not determine expiration. For a post-1995 US utility patent, the ordinary term generally runs 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers and other USPTO-record events [2].

There is no basis in the claim text alone to establish pediatric exclusivity, new chemical entity exclusivity, orphan-drug exclusivity or a patent-term extension. Those are FDA and statutory issues separate from the patent claims [3].

What is the Orange Book status of US Patent 7,037,529?

A patent can be technically relevant to a fenofibrate product without being listed in the FDA Orange Book. Orange Book listing depends on the NDA sponsor’s submission and FDA’s listing rules, not merely on the existence of a patent [3].

For fenofibrate products, Orange Book analysis should distinguish:

Active-ingredient patents.
Formulation patents.
Method-of-use patents.
Manufacturing-process patents.
Patents listed against a particular NDA and strength.
Expired patents that remain visible in historical listings.

US 7,037,529 is principally a formulation and manufacturing patent. It is not an active-ingredient patent covering fenofibrate itself. Its expiration also means that any former Orange Book listing would not create a current patent barrier to an ANDA applicant.

Which companies challenged fenofibrate exclusivity?

Fenofibrate has faced extensive generic competition in the United States. Generic products have been marketed in multiple dosage forms and strengths, including tablets and capsules, depending on the reference product and approval pathway.

The relevant competitive groups include:

The original fenofibrate innovators and their successor commercial owners.
Generic manufacturers filing ANDAs against fenofibrate tablets and capsules.
Manufacturers using micronized or alternative bioavailability-enhancing formulations.
Authorized-generic or licensed generic suppliers.

A Paragraph IV challenge to a listed patent would have required the ANDA applicant to certify that the patent was invalid, unenforceable or not infringed under the Hatch-Waxman framework [4]. Because US 7,037,529 is now outside its ordinary patent term, it is not a current Paragraph IV barrier unless an unusual surviving term or related continuation remains in force.

The supplied claim set does not identify a litigation docket, settlement agreement or particular ANDA challenger. Those matters cannot be established from the claims themselves.

How strong is the patent estate for fenofibrate granulates?

Strengths

The patent has several technically meaningful features:

Multiple independent composition claim families.
Separate coverage of coated particles and deposited layers.
Numerical carrier-particle ranges.
Numerical fenofibrate-to-polymer ratios.
Dissolution thresholds tied to defined test conditions.
Dependent claims covering lactose and polyvinylpyrrolidone.
Process claims covering fluidized-bed spraying.
High-dissolution claims that may capture optimized commercial formulations.

The combination of structure and dissolution performance can make simple substitution difficult if a competing product uses the same carrier-polymer architecture.

Weaknesses

The estate also has substantial design-around and validity pressure points:

“Micronized” may require factual construction and particle-size evidence.
Dissolution claims depend on precise test conditions and reproducibility.
The claims contain drafting inconsistencies and typographical errors.
Claims 85-90 may face written-description, enablement or indefiniteness scrutiny if the specification does not support the full performance range.
Carrier, polymer and surfactant substitutions may avoid dependent claims.
Alternative manufacturing methods may avoid the process claims.
The patent term has ended under the ordinary calculation.

The claim text includes errors such as “weight ratio of micronized fenofibrate polymer” in claim 90 and spelling variations in polymer and surfactant names. Courts generally interpret claims in view of the specification and prosecution history, but errors can create claim-construction disputes.

What generic launch scenarios existed?

Before expiration, the principal launch scenarios were:

Scenario	Description	Risk under US 7,037,529
Same lactose-PVP platform	Micronized fenofibrate sprayed onto lactose with PVP	High historical risk
Same structure, lower dissolution	Identical coated granules but below 75% dissolution	Potentially avoids claims requiring 75%
Different carrier	Insoluble or nonlisted carrier	May avoid dependent claims; independent-claim analysis remains
Different polymer	Nonlisted hydrophilic polymer	May avoid narrow claims but not broad polymer language
Different granulation method	Roller compaction or extrusion	May avoid process claims, not necessarily product claims
Conventional tablet	Fenofibrate blended with excipients without coated carrier particles	Generally lower risk
Capsule or suspension	Different dosage-form architecture	Lower risk unless granule structure is present
Post-expiration launch	Product introduced after ordinary patent expiry	No current infringement risk from the expired patent

What manufacturing and geographic barriers remain?

The patent was a US right. Its enforceability was limited to the United States and US-controlled conduct. Corresponding foreign patents, if granted, would require separate analysis by jurisdiction and could have different expiration dates, claim scope and legal status.

Manufacturing barriers may persist even after patent expiry:

Fluidized-bed coating scale-up.
Uniform deposition of micronized fenofibrate.
Control of agglomeration.
Maintaining carrier-particle size distribution.
Reproducing dissolution across commercial batches.
Managing polymer viscosity and sprayability.
Preventing segregation during compression.
Demonstrating bioequivalence against the applicable reference product.

These are technical and regulatory barriers, not continuing rights under US 7,037,529.

Does US 7,037,529 block current generic fenofibrate entry?

No, not on the ordinary patent-term record. The patent’s claims were commercially relevant to a specific coated-granule technology, but the patent is ordinarily understood to have expired around November 2021. Current generic entry must instead be assessed against:

Any unexpired continuation or divisional patents.
Other formulation patents listed for the target reference product.
FDA exclusivity.
Product-specific Orange Book listings.
Bioequivalence requirements.
Manufacturing know-how and trade secrets.
Foreign patents for non-US launches.

The patent remains relevant as prior art, a technical disclosure, and a historical indicator of the formulation strategies used for rapid fenofibrate dissolution.

Key Takeaways

US 7,037,529 covers fenofibrate granules using micronized fenofibrate and hydrophilic polymer deposited onto carrier particles.
The most commercially important embodiment is likely lactose carrier particles with polyvinylpyrrolidone and micronized fenofibrate.
Independent claims require both a defined formulation architecture and dissolution performance.
Dependent claims narrow the estate through carrier size, polymer identity, particle size, surfactant, composition ratios and tableting.
Process claims target suspension spraying and, in narrower claims, fluidized-bed granulation.
Claims 85-90 cover higher dissolution thresholds of approximately 95.5% to 95.9%.
The ordinary patent term appears to have ended around November 2021.
The patent is not an active-ingredient patent and does not cover fenofibrate generally.
Current US generic risk depends primarily on other unexpired patents, Orange Book listings and FDA requirements.
Design-around routes include alternative carriers, polymers, granulation methods, dosage forms and dissolution profiles.

FAQs About US Patent 7,037,529

Does US Patent 7,037,529 cover all micronized fenofibrate tablets?

No. It covers formulations with the claimed coated-carrier or deposited-layer architecture and the required dissolution performance. A conventional tablet may fall outside the claims.

Is lactose required by the broadest claims?

No. Lactose is a dependent-claim limitation. The broader claims can cover other carrier particles if the remaining structural and dissolution requirements are met.

Is polyvinylpyrrolidone required?

No. Polyvinylpyrrolidone is specifically claimed in dependent claims, but the broad independent claims recite at least one hydrophilic polymer.

Can a product avoid the patent by using a different dissolution medium for testing?

The commercial product’s infringement analysis would focus on the claimed test conditions. Testing under a different method does not by itself establish noninfringement.

Does expiration of this patent eliminate all fenofibrate patent risk?

No. Other formulation, method-of-use, manufacturing or product-specific patents may have existed or may remain relevant. Expiration of US 7,037,529 removes only this patent’s ordinary US enforcement risk.

References

U.S. Patent No. 7,037,529 B2. (2006). Pharmaceutical composition comprising fenofibrate. United States Patent and Trademark Office.
United States Patent and Trademark Office. (2024). Manual of Patent Examining Procedure, Chapter 2700: Patent term. USPTO.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA.
U.S. Code, 35 U.S.C. § 271(e); 21 U.S.C. § 355(j). Hatch-Waxman patent-certification provisions.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
France	97 00479	Jan 17, 1997

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	011411	⤷ Start Trial
Austria	233556	⤷ Start Trial
Austria	291911	⤷ Start Trial
Austria	307576	⤷ Start Trial
Austria	324885	⤷ Start Trial
Australia	5336798	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,037,529

Summary for Patent: 7,037,529