US Patent 7,625,884: Scope, Claims, Expiration, Orange Book Status, and Balsalazide Patent Landscape

US Patent 7,625,884 covered a food-administration method for balsalazide, including administration within 15 minutes after a meal and associated pharmacokinetic effects involving balsalazide, 5-aminosalicylic acid, and N-acetyl-5-aminosalicylic acid. The patent was assigned to Salix Pharmaceuticals and had a nominal expiration date of August 2, 2025. It was a narrow method-of-use patent rather than a composition-of-matter patent. As of 2026, the patent is nominally expired.[1]

The patent’s commercial importance centered on Colazal, the branded balsalazide disodium product approved for mildly to moderately active ulcerative colitis. Its claims targeted administration instructions, patient counseling, food effects, dosing regimens, and selected gastrointestinal disorders.

What does US Patent 7,625,884 cover?

The patent covers a method of treating a gastrointestinal disorder by administering a therapeutically effective amount of balsalazide with food. The core timing limitation requires administration within 15 minutes after eating a meal.[1]

The principal technical limitation is comparative pharmacokinetics. Administration with food must result in increased bioavailability of balsalazide and its metabolites, 5-ASA and NASA, to the colon compared with administration in a fasted state.

Key patent facts

Item	Data
Patent	US 7,625,884 B2
Title	Methods of treating gastrointestinal disorders
Application	US 11/196,950
Priority date	August 2, 2004
Filing date	August 2, 2005
Publication	US 2006/0030085 A1
Issue date	December 1, 2009
Assignee	Salix Pharmaceuticals, Ltd.
Active ingredient	Balsalazide, generally administered as balsalazide disodium
Core product association	Colazal
Patent type	Method of treatment and method-of-use
Nominal expiration	August 2, 2025
PTE identified	None
Current status	Nominally expired as of 2026

The patent did not claim balsalazide itself, the balsalazide molecule, or a general pharmaceutical composition. Its value depended on whether a competing product used the claimed food-related administration method or induced that use through labeling.

How broad is claim 1 of US Patent 7,625,884?

Claim 1 is the broadest independent claim, but it contains several cumulative limitations. A potentially infringing method must satisfy all of the following:

Treatment of a gastrointestinal disorder.
A subject in need of treatment.
Administration of a therapeutically effective amount of balsalazide.
Administration with food.
Administration within 15 minutes after eating a meal.
An increase in colonic bioavailability of balsalazide, 5-ASA, and NASA compared with the fasted state.

The claim is therefore narrower than a general claim to treating ulcerative colitis with balsalazide. It does not cover every administration of balsalazide, every administration with food, or every dosing schedule.

Claim 1 limitation analysis

Limitation	Scope and business significance
“Method of treating”	Requires therapeutic use, not merely manufacturing, selling, or possessing balsalazide
“Gastrointestinal disorder”	Broad category, narrowed by dependent claim 9
“Subject in need of treatment”	Requires a patient or treatment subject
“Therapeutically effective amount”	Functional dosage limitation
“Balsalazide”	Covers the active drug; commercial products generally use balsalazide disodium
“With food”	Requires food-associated administration
“Within 15 minutes after eating”	Creates a specific temporal window
Increased bioavailability to the colon	Requires a comparative pharmacokinetic result
Compared with fasted administration	Establishes the reference condition for comparison

The most important claim-construction issue is the phrase “increase in the bioavailability ... to the colon.” A challenger could argue that ordinary systemic exposure does not establish increased colonic delivery. The patent claims focus on local delivery and metabolite formation rather than only plasma concentration.

A second issue is whether the pharmacokinetic result is an inherent property of practicing the method or an independently provable limitation. In an infringement dispute, the patent owner would likely need evidence showing that the accused dosing method produces the claimed fed-versus-fasted result, or that the result necessarily follows from the claimed administration conditions.

What do claims 2 through 9 add?

The dependent claims add labeling, patient-information, dosage, food, and disease limitations. They do not create a separate composition patent.

Claims 2 and 3: labeling and patient information

Claim 2 requires administration from a container with printed labeling advising that food administration produces one or more pharmacokinetic effects. The listed effects include:

Delayed transit in the colon.
Reduced systemic levels of 5-ASA or NASA.
Reduced maximum plasma concentration, or Cmax.
Delayed time to maximum concentration, or Tmax.
Reduced AUC-last for 5-ASA or NASA.
Increased conversion of balsalazide to 5-ASA.
Increased conversion of 5-ASA to NASA.
Increased systemic NASA-to-5-ASA ratio.

Claim 3 requires informing the patient that administration with food increases bioavailability of balsalazide, 5-ASA, and NASA.

These claims create inducement risk for a manufacturer whose label expressly recommends or instructs administration with food in the claimed timing window. A label that merely states “with or without food” is less direct, although inducement analysis would depend on the full label, promotional materials, prescribing information, and actual intended use.

The labeling limitations also distinguish the patent from a conventional product-by-process claim. The label itself is part of the claimed conduct.

Claims 4 through 7: dosage and regimen limitations

Claim 4 recites several alternative daily-dose ranges:

About 6.25 mg to about 14,000 mg per day.
About 750 mg to about 6,750 mg per day.
About 1,100 mg to about 13,200 mg per day.

These ranges overlap substantially. The practical scope is broad, although the “about” language introduces ordinary claim-construction questions concerning reasonable measurement tolerance.

Claims 5 through 7 identify specific regimens:

Claim	Regimen
5	Three 750 mg capsules three times daily
6	Three 1,100 mg tablets twice daily
7	One 750 mg capsule three times daily

Claim 5 corresponds to a total daily dose of 6,750 mg. Claim 6 corresponds to 6,600 mg per day. Claim 7 corresponds to 2,250 mg per day.

The specific regimens provide narrower fallback positions. A competitor could avoid these claims by using a different dose, strength, frequency, or dosage form, provided it also avoids claim 1 and the other applicable claims.

Claim 8: food limitations

Claim 8 identifies applesauce and a high-fat meal as qualifying food. The high-fat-meal limitation may be relevant to a clinical pharmacology study or labeling language that expressly uses a standardized high-fat meal.

Applesauce is commercially relevant because patients may open or administer capsules with soft food. The claim does not appear to cover every food-independent administration practice.

Claim 9: disease limitations

Claim 9 identifies:

Mildly to moderately active ulcerative colitis.
Radiation proctosigmoiditis.
Colon cancer.

The ulcerative-colitis limitation is the principal commercial application. Balsalazide’s approved US indication is ulcerative colitis, while the radiation proctosigmoiditis and colon cancer references are broader patent-subject-matter categories rather than the main approved product market.[2]

When did US Patent 7,625,884 expire?

The patent had a nominal expiration date of August 2, 2025, based on the earliest claimed priority date of August 2, 2004 and the standard 20-year term under 35 U.S.C. §154.[1][3]

Exclusivity timeline

Date	Event
August 2, 2004	Earliest claimed priority
August 2, 2005	Nonprovisional application filed
February 9, 2006	US patent application publication
December 1, 2009	Patent issued
August 2, 2025	Nominal patent expiration
2026	No ordinary patent exclusivity remains under the stated term

The patent was not a biologic patent and did not create biosimilar exclusivity. Balsalazide is a small-molecule drug, so the relevant competitive pathway is ANDA-based generic entry, not the biosimilar pathway under the Public Health Service Act.

What is the Orange Book status of US Patent 7,625,884?

US Patent 7,625,884 was associated with the Colazal NDA and was listed as a method-of-use patent in FDA Orange Book records for balsalazide disodium products.[2]

An Orange Book listing does not establish that every claim is valid or infringed. It identifies a patent that the NDA holder represented as covering the approved drug or an approved method of use.

Regulatory implications

For an ANDA referencing Colazal, the applicant would generally address listed patents through one of the following certifications:

Paragraph I: No patent information is listed.
Paragraph II: The listed patent has expired.
Paragraph III: The applicant will wait until patent expiration.
Paragraph IV: The patent is invalid, unenforceable, or will not be infringed.

Before the August 2, 2025 expiration date, a Paragraph IV certification could have triggered patent litigation under the Hatch-Waxman framework. After expiration, a Paragraph II certification would generally address this patent, subject to FDA listing data and any applicable patent-term adjustment.

Which companies challenged or competed against Colazal?

Generic balsalazide disodium products entered the US market before the expiration of the 7,625,884 patent estate through ANDA approvals and patent-certification processes. FDA product data identify multiple generic manufacturers and applicants over time, including companies such as Mylan, Teva, Actavis, and Apotex in the balsalazide market.[2][4]

The existence of generic approval does not show that every generic applicant defeated claim 1 of US 7,625,884. Generic entry may have resulted from:

A Paragraph IV certification.
A Paragraph III certification tied to an earlier patent.
A non-infringing label.
A settlement or license.
Expiration of an earlier blocking patent.
A regulatory approach that did not promote the claimed food administration.

The public FDA records establish generic competition but do not, standing alone, establish the precise certification or settlement position of every applicant for every listed patent.

What patent litigation and settlement risks applied?

The principal litigation risk was not direct product infringement by selling balsalazide. It was method-of-use infringement or induced infringement based on how the product was labeled and promoted.

Litigation theories

A patent owner could assert:

Direct infringement under 35 U.S.C. §271(a) against a party practicing the claimed method.
Induced infringement under §271(b) against a manufacturer encouraging the claimed food administration.
Contributory infringement under §271(c), although that theory is more difficult for a broadly usable drug with substantial non-infringing uses.

A generic label stating that balsalazide should be taken within 15 minutes after food would present a stronger inducement case than a label permitting administration with or without food. A label omitting the food instruction would reduce, but not necessarily eliminate, risk if promotional conduct or actual intended use supported inducement.

No settlement term should be inferred solely from FDA approval or Orange Book listing data. A confidential license, covenant not to sue, or private settlement may not be visible in the patent record.

How strong was the patent estate for balsalazide?

The estate was materially weaker than a composition-of-matter estate because it depended on a specific administration condition and a comparative pharmacokinetic outcome.

Strengths

The claim focused on a commercially relevant administration variable.
The patent included multiple fallback regimens.
Claims 2 and 3 addressed labeling and patient counseling.
Claim 9 tied the method to ulcerative colitis, the main approved indication.
Orange Book listing increased the procedural importance of the patent during ANDA review.

Weaknesses

The patent did not cover balsalazide itself.
Generic products could potentially use labels that avoided the claimed food instruction.
The 15-minute timing requirement limited the method.
The increased-colonic-bioavailability limitation could create proof issues.
Food administration was not the only clinically relevant way to administer balsalazide.
The estate expired in 2025.

The patent’s practical blocking power was therefore strongest before generic products entered and during the period when a generic label or promotional program directly instructed the claimed fed administration.

How did US Patent 7,625,884 compare with composition and formulation patents?

Patent category	What it protects	Relevance to balsalazide
Composition-of-matter patent	Active molecule or novel chemical entity	Broadest protection, but generally not the focus of US 7,625,884
Formulation patent	Tablet, capsule, coating, excipient, release profile, or stability	Can block a particular dosage form even after method patents expire
Method-of-use patent	Treatment of a disease or administration method	Category of US 7,625,884
Food-effect patent	PK or therapeutic use tied to fed administration	Specific focus of US 7,625,884
Manufacturing patent	Synthesis, purification, or commercial production process	May create supply-chain barriers without blocking all generic products
Regulatory exclusivity	FDA approval-based protection	Separate from patent term and does not replace patent protection

US 7,625,884 did not prevent competitors from making or selling every balsalazide product. It targeted a defined treatment method and associated labeling conduct.

What generic launch risks remain after expiration?

After August 2, 2025, this patent no longer creates a normal patent barrier to generic use of the claimed food-administration method. Remaining risks would arise from other unexpired patents, regulatory requirements, product-specific formulation claims, manufacturing patents, or commercial factors.

The relevant launch scenarios are:

A generic launches with a label permitting administration with or without food.
A generic launches after expiration of all blocking Orange Book patents.
A generic avoids a food-specific instruction and competes on price and availability.
A generic faces residual risk from separate formulation, process, or labeling patents.
A manufacturer uses a different strength or regimen that does not practice claims 5 through 7.

Because balsalazide is a small molecule with multiple generic products, biosimilar risk is not relevant. The competitive risk is generic substitution, distributor contracting, reimbursement pressure, and possible authorized-generic strategies.

What licensing and geographic rights applied?

The patent was a US patent and had territorial effect in the United States. It did not, by itself, create rights in Canada, Europe, Japan, or other jurisdictions. Foreign family members would require separate analysis.

The US patent record identifies Salix Pharmaceuticals as the relevant assignee during prosecution and issuance.[1] FDA records connect the patent to the Colazal regulatory estate.[2] The cited public records do not establish a separate commercial license or cross-license specific to the food-effect claims.

Geographic coverage

Jurisdiction	Effect of US 7,625,884
United States	Enforceable only during the patent term, subject to validity and procedural defenses
European Union	No direct effect
Canada	No direct effect
Japan	No direct effect
Other countries	Requires separate national patent rights

Key Takeaways

US Patent 7,625,884 covered administering balsalazide within 15 minutes after eating.
Claim 1 required increased colonic bioavailability compared with fasting.
The patent included claims directed to labeling, patient information, dosing regimens, applesauce, high-fat meals, and ulcerative colitis.
It was a method-of-use patent, not a composition-of-matter patent.
The patent was associated with the Colazal Orange Book estate.
Its nominal expiration date was August 2, 2025.
Generic competition was governed by ANDA certifications, labeling strategy, and other balsalazide patents.
Biosimilar competition does not apply because balsalazide is a small molecule.
As of 2026, this patent no longer provides ordinary patent exclusivity.

FAQs

Does taking balsalazide with food infringe US Patent 7,625,884?

It could have implicated the patent before expiration if the administration occurred within 15 minutes after a meal and produced the claimed fed-state increase in colonic bioavailability. The patent’s nominal term ended August 2, 2025.

Did US Patent 7,625,884 cover all Colazal use?

No. It covered a defined food-related administration method. It did not broadly cover every use, formulation, sale, or manufacture of balsalazide.

Was the patent a formulation patent?

No. The claims focused on treatment administration, pharmacokinetic effects, labeling, counseling, dosage regimens, and selected diseases.

Could a generic balsalazide label avoid the patent?

Before expiration, a generic could reduce risk by avoiding instructions that expressly directed administration within 15 minutes after food. The complete label and promotional conduct would control the inducement analysis.

Does the patent affect current balsalazide generic launches?

Not as an ordinary unexpired patent barrier after August 2, 2025. Current launch analysis must examine other Orange Book patents, formulation rights, manufacturing patents, regulatory requirements, and commercial constraints.

References

United States Patent and Trademark Office. (2009). US Patent No. 7,625,884 B2: Methods of treating gastrointestinal disorders.
U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book.
35 U.S.C. §154. (2024). Contents and term of patent; provisional rights.
U.S. Food and Drug Administration. (2025). Drugs@FDA: FDA-approved drugs, Colazal and generic balsalazide disodium products.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Valeant Pharms Intl	GIAZO	balsalazide disodium	TABLET;ORAL	022205-001	Feb 3, 2012		DISCN	Yes	No	7,625,884	⤷ Start Trial				TREATMENT OF MILDLY TO MODERATELY ACTIVE ULCERATIVE COLITIS IN MALE PATIENTS	⤷ Start Trial
Valeant Pharms Intl	COLAZAL	balsalazide disodium	CAPSULE;ORAL	020610-001	Jul 18, 2000	AB	RX	Yes	Yes	7,625,884*PED	⤷ 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
Australia	2006282865	⤷ Start Trial
Australia	2007322362	⤷ Start Trial
Brazil	PI0615195	⤷ Start Trial
Brazil	PI0717859	⤷ Start Trial
Canada	2620091	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,625,884

Which drugs does patent 7,625,884 protect, and when does it expire?

Summary for Patent: 7,625,884