United States Patent 6,277,405: Fenofibrate Formulation Claims, Patent Scope, Expiration, and Generic Risk

U.S. Patent No. 6,277,405 protected oral compositions containing micronized fenofibrate, a water-soluble carrier, and a defined dissolution profile. The patent covered tablets and capsule granules, with dependent claims directed to particle size, hydrophilic polymers, surfactants, and concentration ranges. It issued on August 21, 2001, and its ordinary patent term expired in 2018 based on the underlying international filing date. The patent therefore does not create a current U.S. barrier to generic fenofibrate development.

The commercial importance of the patent arose from reformulated fenofibrate products, including Tricor, that improved dissolution and oral absorption compared with earlier fenofibrate formulations. The patent was formulation-specific. It did not broadly cover the fenofibrate molecule, all fenofibrate products, or every micronized fenofibrate composition.

What does U.S. Patent 6,277,405 cover?

U.S. Patent 6,277,405 covers a pharmaceutical composition that combines:

A hydrosoluble, or water-soluble, carrier;
Micronized fenofibrate; and
A specified dissolution performance measured under a defined European Pharmacopoeia rotating-blade test.

Claim 1 requires the composition to dissolve at least:

Time point	Minimum dissolved fenofibrate
5 minutes	10%
10 minutes	20%
20 minutes	50%
30 minutes	75%

The test must use a rotating blade at 75 rpm, with water containing either 2% polysorbate 80 or 0.025 M sodium lauryl sulfate. Those testing conditions are material claim limitations, not merely examples of acceptable testing.

The claims are composition claims. They do not primarily claim a manufacturing process, a treatment method, or fenofibrate as an active pharmaceutical ingredient.

How should the claims of U.S. 6,277,405 be interpreted?

Claim 1: Core formulation claim

Claim 1 is the independent claim and establishes the principal infringement test. A potentially infringing product would need to satisfy each required element:

It must be a composition.
It must contain a hydrosoluble carrier.
It must contain micronized fenofibrate.
It must meet all four dissolution thresholds.
The dissolution must be measured using the specified rotating-blade method and medium.

The claim is cumulative. Achieving the dissolution threshold at 30 minutes would not be sufficient if the composition fails the 5-, 10-, or 20-minute threshold.

The use of a dissolution limitation gives the claim a performance-based boundary. A formulation with the same ingredients may fall outside the claim if it does not meet the required dissolution profile. Conversely, a formulation using different excipients may fall within the claim if it contains the required carrier and micronized fenofibrate and meets the test.

Claims 2 and 3: Dosage-form limitations

Claim 2 limits the composition to a tablet. Claim 3 limits it to granules inside a capsule.

These claims do not broaden claim 1. They narrow the scope to specific oral dosage forms. A tablet must still satisfy every limitation of claim 1. Capsule granules must also satisfy the composition and dissolution requirements.

Claims 4 and 5: Particle-size limitations

Claim 4 requires fenofibrate particles with a size of 20 micrometers or less. Claim 5 narrows that requirement to 10 micrometers or less.

The particle-size claims create a technical distinction between ordinary fenofibrate and more highly micronized material. Particle-size measurement can be legally significant because results may vary depending on the analytical technique, including laser diffraction, microscopy, and sampling protocol.

The claims also use the plural formulation "micronized fenofibrate have a size," which should be read in context with the specification and applicable claim-construction principles. The practical question is whether the claimed particle-size limitation applies to the relevant fenofibrate population, rather than whether every isolated particle must fall below the stated threshold.

Claim 6: Fenofibrate concentration

Claim 6 requires fenofibrate to represent 20% to 45% by weight of the composition.

This limitation excludes compositions outside that concentration range. A product containing 50% fenofibrate, for example, would not meet claim 6, although it could still fall within claim 1 if it satisfied the broader limitations of that claim.

Claims 7 through 9: Hydrophilic polymers

Claim 7 adds a hydrophilic polymer. Claim 8 identifies qualifying polymers, including:

Polyvinylpyrrolidone;
Polyvinyl alcohol;
Hydroxypropylcellulose;
Hydroxymethylcellulose;
Hydroxypropylmethylcellulose;
Gelatin; or
A mixture of those polymers.

Claim 9 requires the hydrophilic polymer to comprise 20% to 45% by weight.

These claims target formulations in which the polymer helps disperse fenofibrate, improve wetting, control granule structure, or support the required dissolution profile. The polymer claims are dependent and do not independently cover all fenofibrate-polymer systems.

Claims 10 through 12: Surfactants

Claim 10 adds a surfactant. Claim 11 lists a broad group of surfactants, including sodium lauryl sulfate, polysorbate-type materials, lecithin, poloxamers, and related surface-active agents. Claim 12 limits the surfactant concentration to 0.1% to 3% by weight.

A surfactant is not required by claim 1. It becomes a required element only for claims 10 through 12. This distinction matters when evaluating design-around options.

Claim 13: Hydrosoluble-carrier concentration

Claim 13 requires the hydrosoluble carrier to comprise 20% to 50% by weight.

Claim 1 requires the presence of a hydrosoluble carrier but does not impose an express carrier concentration range. Claim 13 therefore narrows claim 1 by adding the 20% to 50% range.

What are the key claim dependencies in U.S. 6,277,405?

Claim	Subject matter	Additional limitation
1	Core composition	Hydrosoluble carrier, micronized fenofibrate, dissolution profile
2	Tablet	Claim 1 composition in tablet form
3	Capsule	Claim 1 composition as granules inside a capsule
4	Particle size	Fenofibrate size of 20 micrometers or less
5	Narrow particle size	Fenofibrate size of 10 micrometers or less
6	Drug loading	Fenofibrate at 20% to 45% by weight
7	Polymer	Hydrophilic polymer
8	Polymer identity	Specified polymers or mixtures
9	Polymer loading	Polymer at 20% to 45% by weight
10	Surfactant	Surfactant
11	Surfactant identity	Specified surfactants or mixtures
12	Surfactant loading	Surfactant at 0.1% to 3% by weight
13	Carrier loading	Hydrosoluble carrier at 20% to 50% by weight

Claims 4, 6, 7, 10, and 13 each depend directly or indirectly on claim 1. Claims 5 and 8 depend on narrower parent claims. A product can infringe claim 1 without infringing claims 4 through 13 if it lacks the additional limitations.

What technical problem did the patent address?

Fenofibrate has poor aqueous solubility. Micronization reduces particle size and increases surface area, but micronization alone does not necessarily provide consistent dissolution or absorption. The claimed formulation approach combines micronized fenofibrate with a water-soluble carrier and, in narrower embodiments, a hydrophilic polymer or surfactant.

The patent's technical distinction is therefore the combination of:

Micronized active ingredient;
Excipients that promote dispersion or wetting; and
A measured dissolution profile.

The dissolution requirement is central. It links the formulation structure to a measurable pharmaceutical-performance result.

What patents protect fenofibrate products besides U.S. 6,277,405?

The fenofibrate patent landscape historically included several categories:

Patent category	Typical subject matter	Relevance to current entry
Active-ingredient patents	Fenofibrate molecule and related chemistry	Generally expired
Micronization patents	Particle size and manufacturing conditions	Historically important; generally expired
Formulation patents	Solubilizing carriers, polymers, surfactants, and dissolution	U.S. 6,277,405 is an example
Dosage-form patents	Tablets, capsules, granules, and strengths	Historically relevant to branded reformulations
Method-of-use patents	Treatment of dyslipidemia and related conditions	Limited relevance after expiration
Manufacturing patents	Milling, granulation, blending, and tableting	Potential process barriers during the original term
Regulatory exclusivity	NDA exclusivity for approved products	Separate from patent rights and generally expired for mature products

U.S. 6,277,405 should be analyzed with related fenofibrate formulation patents, including U.S. Patent No. 6,074,670, which was also associated with reformulated fenofibrate products. Related patents can affect the same product even when one patent has a narrower claim set.

A freedom-to-operate review should distinguish patent-family overlap from actual claim overlap. A related patent may cover a different carrier, dosage strength, particle-size distribution, or manufacturing step.

What was the Orange Book status of U.S. 6,277,405?

U.S. 6,277,405 was associated with the U.S. regulatory and commercial protection for reformulated fenofibrate products, including Tricor products. Orange Book listings must be evaluated by product, NDA, dosage form, and listing history rather than by patent number alone. The FDA Orange Book records patents and, where applicable, use codes submitted by NDA holders under the Hatch-Waxman framework (FDA, 2024).

The patent was not a biologic patent and did not implicate the biosimilar pathway. Fenofibrate is a small-molecule drug. Generic applicants would ordinarily use the abbreviated new drug application pathway under section 505(j) of the Federal Food, Drug, and Cosmetic Act.

The patent's ordinary term expired in 2018. Any historical Orange Book listing therefore does not provide a current patent-based exclusion period.

When did U.S. 6,277,405 lose exclusivity?

U.S. 6,277,405 reached the end of its ordinary 20-year term in 2018, calculated from the applicable international filing date. The effective date should be confirmed against the USPTO patent record for any patent-term adjustment, disclaimer, or correction. No current commercial exclusivity should be attributed to this patent.

The patent's expiration differs from FDA regulatory exclusivity:

Patent term arises under the Patent Act.
New-drug exclusivity arises under the Food, Drug, and Cosmetic Act.
Orange Book listing affects Hatch-Waxman notice and litigation procedures.
None of those mechanisms revives an expired formulation patent.

Which companies challenged the fenofibrate patent estate?

Fenofibrate generic development produced Hatch-Waxman litigation involving generic applicants, including Teva and other manufacturers, against the branded-product owners and their affiliates. Historical litigation addressed patents such as U.S. 6,074,670 and U.S. 6,277,405 and focused on validity, infringement, and the effect of abbreviated applications.

The principal legal risk at the time was a Paragraph IV certification. A Paragraph IV certification asserts that a listed patent is invalid, unenforceable, or will not be infringed. Filing an ANDA with a Paragraph IV certification can trigger a 45-day period for the patent owner to file suit and can create a statutory 30-month stay of FDA approval under the Hatch-Waxman framework.

Because U.S. 6,277,405 has expired, a new Paragraph IV challenge to that patent would no longer be the normal mechanism for commercial entry. Current generic risk would instead turn on any unexpired patents, regulatory requirements, product-specific exclusivity, and non-patent commercial factors.

What patent litigation affected U.S. 6,277,405?

The patent was part of historical litigation over reformulated fenofibrate products. The disputes involved whether the claimed dissolution performance and formulation features were patentable and whether generic products met the asserted limitations.

The principal litigation issues for a patent with this claim structure would include:

Whether the prior art disclosed micronized fenofibrate with the claimed excipient system;
Whether the dissolution profile was inherent or predictable from the prior art;
Whether the accused product met the specified dissolution test;
Whether the patent's claim language required a particular particle-size distribution;
Whether the formulation claims were obvious in view of known solubility problems; and
Whether the patent remained enforceable after any litigation ruling or settlement.

Historical settlements in pharmaceutical litigation can include delayed entry, licenses, authorized generic arrangements, or other commercial terms. Settlement terms for fenofibrate disputes should not be inferred solely from the existence of a case or an ANDA filing. Public court records and FDA approval dates are the controlling sources for litigation chronology.

How strong was the patent estate for fenofibrate formulations?

Strengths

The patent had several features that could support enforcement during its term:

A specific dissolution profile;
Defined test conditions;
Multiple dosage-form claims;
Particle-size limitations;
Polymer and surfactant fallback claims;
Concentration ranges for active ingredient and excipients.

The layered structure gave the patent owner multiple claim positions. A generic product might avoid a narrow particle-size or surfactant claim but still face claim 1 if its formulation met the dissolution test.

Weaknesses

The estate also had potential vulnerabilities:

Micronization was a known approach to improving fenofibrate dissolution;
Hydrophilic carriers and surfactants were common pharmaceutical excipients;
Dissolution performance can be argued to be an expected result of routine formulation optimization;
The claim required a specific test protocol that could create reproducibility and construction disputes;
A product could potentially design around the narrower concentration and ingredient claims.

The strongest infringement position would generally require reliable evidence that the accused product meets the claim 1 dissolution thresholds under the specified medium and apparatus. The strongest validity challenge would focus on prior-art combinations that disclose micronized fenofibrate, hydrophilic excipients, and predictable dissolution improvement.

What generic entry risks exist for fenofibrate?

For current U.S. development, U.S. 6,277,405 presents no live patent-term barrier. Generic manufacturers should still evaluate:

Unexpired patents associated with the specific reference-listed drug;
Product-specific labeling and dosage-form requirements;
Bioequivalence and dissolution specifications;
Manufacturing-process patents not captured by the expired patent;
Regulatory exclusivity or pediatric exclusivity;
Trade dress and trademark constraints;
Supply-chain access to compliant micronized fenofibrate;
Comparative commercial positioning against multiple generic suppliers.

A generic product may use a different carrier, polymer, surfactant, or particle-size profile. Since claim 1 is now expired, those design-around choices have greater commercial and formulation significance than patent-avoidance significance.

How does U.S. 6,277,405 compare with method-of-use and manufacturing patents?

U.S. 6,277,405 is principally a formulation patent. It does not claim:

A method of treating hyperlipidemia in a patient;
A specific dosing regimen;
A milling apparatus;
A granulation process as such;
A manufacturing facility;
Fenofibrate's chemical identity independent of the formulation.

That distinction is important in ANDA and freedom-to-operate analysis. A manufacturer can avoid a formulation claim but still encounter a process patent. Conversely, an expired process or formulation patent cannot block market entry based on the same claim scope.

What licensing and commercial transfers affected the patent?

Fenofibrate commercial rights moved through the Fournier and Abbott commercial organizations, with later operations associated with AbbVie following Abbott's separation of its research-based pharmaceutical business. Product commercialization and patent ownership are separate questions. A licensee may market a product without owning every patent, while a patent assignment may occur independently of a product-rights transaction.

The relevant diligence points are:

Assignment records at the USPTO;
NDA ownership and supplement history;
Orange Book patent submissions;
ANDA litigation records;
Any publicly filed settlement or license agreement.

No current license can extend the expired statutory term of U.S. 6,277,405.

What is the current commercial landscape for fenofibrate?

Fenofibrate is a mature small-molecule lipid-modifying therapy with generic competition in the United States. The market includes immediate-release and modified formulations differentiated by strength, dosage form, bioequivalence status, manufacturer, and payer position.

The principal commercial risk to a branded fenofibrate product is substitution by approved generics rather than biosimilar competition. Revenue exposure depends on the product's remaining branded share, rebate structure, prescription volume, and the number of approved generic suppliers.

Key Takeaways

U.S. 6,277,405 is a formulation patent for micronized fenofibrate.
Claim 1 requires a hydrosoluble carrier, micronized fenofibrate, and four dissolution thresholds under a specified test method.
Claims 2 and 3 cover tablets and capsule granules.
Claims 4 through 13 narrow the invention by particle size, drug loading, polymers, surfactants, and carrier concentration.
The patent does not broadly cover fenofibrate or all fenofibrate products.
The ordinary U.S. patent term expired in 2018.
The patent was historically relevant to Tricor and related reformulated products.
It is not a current U.S. patent barrier to generic fenofibrate entry.
Fenofibrate is a small molecule, so biosimilar analysis is not applicable.
Current diligence should focus on any later, unexpired product, process, or formulation patents and on FDA product-specific requirements.

FAQs About U.S. Patent 6,277,405

Does U.S. 6,277,405 cover all micronized fenofibrate?

No. It covers compositions that satisfy the carrier, micronized-fenofibrate, and dissolution limitations of claim 1. Narrower claims add particle-size and excipient requirements.

Is U.S. 6,277,405 still enforceable?

The patent's ordinary term expired in 2018. It should not be treated as a current enforceable exclusion right absent an unusual legal event reflected in the USPTO record.

Does the patent cover fenofibrate capsules?

Claim 3 covers granules inside a capsule, but only when the composition also satisfies claim 1.

Can a product avoid the patent by using non-micronized fenofibrate?

During the patent term, non-micronized fenofibrate could avoid the micronized-fenofibrate limitation, but the resulting product would still require analysis against other fenofibrate patents. Today, the patent is expired.

Does the patent cover a fenofibrate manufacturing process?

No. The claims provided are composition claims. They do not independently claim milling, granulation, blending, compression, or another manufacturing operation.

What FDA pathway applies to a generic fenofibrate product?

A generic manufacturer would generally use an ANDA under section 505(j), subject to product-specific bioequivalence, quality, labeling, and patent-certification requirements.

References

U.S. Patent and Trademark Office. (2001). U.S. Patent No. 6,277,405, Pharmaceutical compositions containing micronized fenofibrate. https://patents.google.com/patent/US6277405
U.S. Patent and Trademark Office. (2000). U.S. Patent No. 6,074,670, Pharmaceutical composition containing fenofibrate. https://patents.google.com/patent/US6074670
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/
U.S. Food and Drug Administration. (2024). Abbreviated new drug application (ANDA) process. https://www.fda.gov/drugs/types-applications/abbreviated-new-drug-application-anda/abbreviated-new-drug-application-anda-process generative.

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
Australia	731964	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,277,405

Summary for Patent: 6,277,405