US Patent 6,717,015: Venlafaxine Besylate Claims, Expiration, Orange Book Status, and Generic Risk

US Patent 6,717,015 covers venlafaxine besylate as a chemical compound, its crystalline monohydrate and anhydrate forms, pharmaceutical compositions, extended-release tablets and pellets, therapeutic use, and a melt-processing method. The patent is materially broader than a single once-daily tablet because it includes the salt itself, racemic and enantiomeric forms, multiple matrix systems, dosage forms, dissolution profiles, and manufacturing steps.

The patent issued on April 6, 2004, from an application claiming a 1999 priority date. Its ordinary US patent term ended in 2020. The principal commercial risk today is historical rather than current: venlafaxine hydrochloride generics generally avoided literal infringement because the patent claims venlafaxine besylate, not venlafaxine hydrochloride.

What does US Patent 6,717,015 protect?

The patent has five principal claim groups:

Claim group	Claims	Protected subject matter
Chemical compounds	1-7	Venlafaxine besylate, crystalline forms, monohydrate, anhydrate, racemate, and substantially pure enantiomers
Pharmaceutical compositions	8-32	Excipients, tablets, pellets, granules, unit doses, extended release, matrix systems, and dissolution profiles
Treatment methods	33-37	Administration of venlafaxine besylate for venlafaxine-treatable conditions, including depression
Manufacturing processes	38-49	Melt processing with fusible carriers, granulation, pellet formation, tableting, and extended-release products
Product-performance limitations	17, 18, 31, 49	Specific in-vitro release thresholds using USP Apparatus 1

The broadest claim is claim 1: “A venlafaxine besylate compound.” It is a composition-of-matter claim to the besylate salt. Claims 2-7 narrow the salt by crystal form and stereochemistry.

Claim 8 separately covers a pharmaceutical composition containing venlafaxine besylate and at least one pharmaceutically acceptable excipient. The composition claims are not limited to a specific commercial formulation unless the dependent claim introduces that limitation.

How broad is claim 1 to venlafaxine besylate?

Claim 1 is structurally broad but chemically specific. It covers venlafaxine in the besylate, or benzenesulfonate, salt form. It does not expressly require:

crystallinity;
a monohydrate or anhydrate;
a particular particle size;
a particular dosage;
an extended-release profile;
a tablet or capsule;
a specific excipient; or
a particular stereochemical composition.

The claim therefore reaches noncrystalline venlafaxine besylate and, subject to claim construction and the specification, both racemic and enantiopure versions. Claims 3 and 7 confirm that the inventors intended the compound genus to include racemic venlafaxine and substantially pure (+) or (-) enantiomers.

A generic product containing only venlafaxine hydrochloride would not literally satisfy claim 1. Salt-form identity is a central infringement distinction. Venlafaxine hydrochloride and venlafaxine besylate have different counterions and are different chemical compounds.

What do claims 2 through 7 add?

Claims 2, 4, and 6 focus on solid-state forms:

claim 2: crystalline venlafaxine besylate;
claim 4: crystalline venlafaxine besylate monohydrate;
claim 6: crystalline venlafaxine besylate anhydrate.

Claim 5 narrows claim 4 to crystalline racemic venlafaxine besylate monohydrate. Claim 7 covers a pure or substantially pure (+) or (-) venlafaxine enantiomer in besylate form.

These claims create a polymorph and hydrate coverage layer. A product that avoids a particular crystalline form may still fall within claim 1 if it contains venlafaxine besylate in another form. Conversely, a product using venlafaxine hydrochloride avoids the salt-specific claims.

What formulations are protected by US 6,717,015?

The formulation claims cover conventional solid oral dosage forms and controlled-release matrix systems.

Immediate formulation scope

Claims 8-15 cover compositions containing venlafaxine besylate with excipients such as:

hydroxypropyl methylcellulose, or HPMC;
microcrystalline cellulose;
calcium phosphates;
sugars;
hydrogenated castor oil;
glyceryl behenate;
glyceryl palmitostearate;
saturated polyglycolyzed glycerides; and
lubricants.

The claims extend to granules, pellets, powder blends, tablets, and unit dosage forms containing between 30 mg and 300 mg of venlafaxine besylate.

The 30 mg to 300 mg limitation in claim 15 is important. It is a dependent limitation and does not restrict claim 8, which has no stated dose range. The claim language also refers to the amount of venlafaxine besylate. Commercial labeling may express strength as venlafaxine hydrochloride equivalent or venlafaxine base, creating a conversion issue in any infringement analysis.

Extended-release composition claims

Claims 16-32 are directed to extended-release products. They cover:

once-daily tablets;
hydrogel tablets;
hydrophilic matrix systems;
lipophilic matrix systems;
biodegradable matrix systems;
HPMC-based tablets;
wax-based matrices;
pellet formulations; and
products meeting specified dissolution profiles.

The principal matrix materials are HPMC, glyceryl palmitostearate, glyceryl behenate, and hydrogenated castor oil.

Claim 23 is particularly relevant to HPMC formulations. It requires a tablet comprising HPMC and venlafaxine besylate. Claim 24 adds calcium phosphate, microcrystalline cellulose, or a lubricant. Claims 26-29 address lipophilic matrix tablets, including once-daily products.

What dissolution profile is required by the patent?

Claims 18, 31, and 49 require the following average release profile:

Time	Average venlafaxine besylate released
2 hours	Less than 30%
4 hours	30% to 55%
8 hours	55% to 80%
12 hours	65% to 90%
24 hours	More than 80%

The test conditions are USP Apparatus 1, basket method, 100 rpm, purified water, and 37°C. Claim 17 provides a related limitation requiring less than 30% release at two hours in purified water or simulated gastric fluid.

These are product-performance limitations. A formulation may infringe even if it uses different excipients from those expressly named in narrower claims, provided it satisfies a broader composition claim and any applicable release limitation. Conversely, a product containing venlafaxine besylate may avoid claims 18, 31, and 49 if it does not meet the claimed dissolution profile, while remaining exposed to claim 1 or claim 8.

How do the method-of-use claims operate?

Claims 33-37 cover administering an effective amount of venlafaxine besylate to treat a venlafaxine-treatable disease or condition.

The claims narrow through:

tablet administration;
treatment of depression;
once-daily dosing; and
oral administration in one or two tablets once daily.

Claim 33 is not limited to depression and could cover other conditions for which venlafaxine is used, subject to the scope of the specification and applicable claim-construction principles. Claim 35 is narrower because it expressly requires depression and an antidepressant amount.

These method claims would be most relevant where a product label instructs use of venlafaxine besylate for a claimed condition. A generic label directed only to venlafaxine hydrochloride would present a different analysis because the administered compound is not the claimed besylate.

What manufacturing processes are protected?

Claims 38-49 cover a melt-processing route:

Venlafaxine besylate is mixed with a molten fusible carrier.
The partially melted mass is cooled.
The solidified product is converted into granules, pellets, or tablets.
The product may be milled and blended with excipients and lubricant.
The resulting tablet may be extended release and may satisfy the claimed dissolution profile.

The process claims identify waxes and lipophilic matrix materials as preferred carriers. Calcium phosphates, microcrystalline cellulose, and lactose may be added during processing.

This is process-specific protection. A manufacturer using direct compression, aqueous granulation, dry granulation, or another non-melt process would generally avoid literal infringement of claim 38, although the resulting product could still implicate claims 1, 8, or 16.

When did US Patent 6,717,015 lose exclusivity?

Published patent records identify a 1999 priority date for US 6,717,015. Under the modern US patent-term framework, the 20-year term ran to approximately September 2020, subject to any patent-term adjustment or other term event recorded in the official file. The patent issued on April 6, 2004.

Event	Date
Earliest identified priority	September 1999
US filing period	2000
Patent issued	April 6, 2004
Approximate ordinary term end	September 2020
Current commercial status	Expired term

The patent’s term has therefore ended. It does not presently block an ANDA applicant through an unexpired patent right.

What is the Orange Book status of US 6,717,015?

US 6,717,015 is not the principal patent associated with Effexor XR’s original venlafaxine hydrochloride product. Effexor and Effexor XR were marketed as venlafaxine hydrochloride products, while US 6,717,015 claims venlafaxine besylate.

The key regulatory distinction is:

Product	Active salt	Relevance of US 6,717,015
Effexor immediate release	Venlafaxine hydrochloride	No direct salt-form match
Effexor XR	Venlafaxine hydrochloride	No direct salt-form match
A venlafaxine besylate product	Venlafaxine besylate	Directly within the chemical claim scope
Generic venlafaxine HCl ER	Venlafaxine hydrochloride	Generally avoids literal infringement of besylate claims

FDA Orange Book patent listings for venlafaxine products historically centered on hydrochloride formulations and controlled-release technologies, including patents associated with Effexor XR. The Orange Book listing status must be distinguished from the broader patent-family landscape. A patent can affect product freedom to operate without being the listed patent that supports an NDA certification.

Which companies challenged venlafaxine exclusivity?

The principal generic competition involved venlafaxine hydrochloride and extended-release formulations. Generic manufacturers and applicants included companies such as Teva, Impax, Sandoz, Wockhardt, and other ANDA sponsors active in the venlafaxine market.

The significant litigation issue for those products was generally the scope and validity of Wyeth’s venlafaxine hydrochloride extended-release patents, not direct infringement of US 6,717,015. Paragraph IV certifications against Orange Book-listed Effexor XR patents created the primary litigation pathway.

A Paragraph IV certification against a listed hydrochloride formulation patent does not automatically challenge a besylate patent. Each patent must be mapped to the active ingredient, salt, dosage form, formulation, and method disclosed in the ANDA.

What patent litigation affects venlafaxine besylate?

The principal risk vectors are distinct:

Risk vector	Assessment for US 6,717,015
Direct infringement by venlafaxine HCl generic	Low because the counterion differs
Direct infringement by venlafaxine besylate product	Historically high while the patent was unexpired
Polymorph claim exposure	Relevant to crystalline monohydrate and anhydrate products
Extended-release formulation exposure	Relevant only if the product contains besylate and meets claimed composition or release limitations
Process claim exposure	Depends on use of the melt-processing route
Current injunction risk	None from an expired patent
Paragraph IV relevance today	Historical, unless another unexpired related patent applies

Publicly reported venlafaxine generic litigation primarily concerned the Effexor XR patent estate. The available record does not establish that US 6,717,015 was the central patent in those hydrochloride-product disputes.

How strong was the patent estate for venlafaxine besylate?

The patent was strong in breadth at the compound level because claim 1 covered the besylate salt without requiring a formulation or release profile. Its dependent claims created additional layers around crystalline forms, racemic material, and enantiomers.

Its commercial strength was narrower than its legal breadth because the major branded products used venlafaxine hydrochloride. A salt-specific patent has limited blocking power against a competing product using a different pharmaceutically acceptable salt, unless the competitor’s manufacturing or formulation process necessarily passes through the besylate form.

Strength by claim category

Claim category	Historical strength	Main limitation
Compound claim	High	Limited to besylate salt
Polymorph claims	Moderate to high	Requires proof of claimed solid-state form
Broad composition claim	Moderate	Requires venlafaxine besylate in the composition
Extended-release claims	Moderate	Formulation and dissolution limitations narrow scope
Method claims	Moderate	Depends on labeled use and administered salt
Process claims	Moderate	Requires proof of the melt-processing steps
Current enforceability	None	Patent term expired

How does US 6,717,015 compare with Effexor XR patents?

US 6,717,015 and the principal Effexor XR patents protect different technical positions.

Issue	US 6,717,015	Effexor XR patent estate
Active salt	Venlafaxine besylate	Primarily venlafaxine hydrochloride
Core technology	Salt, solid forms, matrices, melt processing	Extended-release venlafaxine formulations
Commercial product match	Limited for Effexor XR	Direct
Generic pathway	Besylate-specific product or process	ANDA challenges to HCl ER products
Typical design-around	Use HCl or another salt	Alter formulation, release profile, or dosing system
Current term	Expired	Principal patents also expired or have historical expiration dates

The comparison shows why generic venlafaxine hydrochloride products could enter despite the existence of a besylate patent. The products did not need to practice the claimed salt.

What generic launch scenarios existed?

Three launch scenarios were commercially relevant:

Venlafaxine hydrochloride immediate-release launch. This product avoided the besylate compound claims and faced the relevant HCl product patents.
Venlafaxine hydrochloride extended-release launch. This required analysis of Effexor XR formulation patents, Orange Book listings, Paragraph IV certifications, and possible 30-month stays.
Venlafaxine besylate launch. Before September 2020, this product faced direct exposure under claim 1 and potentially claims 2-32. After expiration, the patent no longer prevented launch.

A besylate product launched before expiration would have required a freedom-to-operate analysis covering the salt, crystal form, dosage form, dissolution profile, and manufacturing route. A post-expiration product faces ordinary regulatory, formulation, manufacturing, and trade-secret issues rather than this patent’s term.

What geographic coverage did the patent provide?

US 6,717,015 provided protection only in the United States. International family members, if granted, required separate analysis by jurisdiction. The US expiration date did not automatically determine the status of corresponding European, Canadian, Australian, or other foreign patents.

Geographic risk depended on:

whether a national counterpart was granted;
the local patent-term calculation;
supplementary protection or term-adjustment rules;
local validity decisions;
Orange Book or equivalent linkage procedures; and
whether the marketed product used besylate or hydrochloride.

Were licensing deals associated with the patent?

Wyeth was the principal innovator associated with venlafaxine and the Effexor product franchise. Public patent records identify the patent with the Wyeth venlafaxine program. No widely reported settlement or license agreement is established as a continuing encumbrance on US 6,717,015 after patent expiration.

Any historic license, assignment, or settlement would not extend the statutory patent term. Contractual restrictions could survive separately, but they would not create patent exclusion after expiration.

Key Takeaways

US 6,717,015 claims venlafaxine besylate as a compound, including crystalline, hydrate, anhydrate, racemic, and enantiomeric forms.
Claims 8-32 cover pharmaceutical compositions, extended-release tablets, pellets, matrix systems, excipients, and dissolution profiles.
Claims 33-37 cover treatment methods, including once-daily treatment of depression.
Claims 38-49 cover melt processing with fusible carriers, granulation, pellet formation, and extended-release tableting.
The patent’s commercial blocking position was narrower than its compound-claim language because Effexor and Effexor XR used venlafaxine hydrochloride.
Venlafaxine hydrochloride generics generally avoided literal infringement of the besylate claims.
The patent’s ordinary US term ended in approximately September 2020.
No biosimilar pathway applies because venlafaxine is a small-molecule drug. Generic competition proceeds through the ANDA pathway.
Current launch risk from this patent is limited to historical analysis because the patent has expired.

FAQs About US Patent 6,717,015

Does venlafaxine hydrochloride infringe US 6,717,015?

Generally, no literal infringement arises solely from using venlafaxine hydrochloride because the patent claims venlafaxine besylate, which has a different counterion.

Does the patent cover venlafaxine besylate monohydrate?

Yes. Claims 4, 5, and 32 specifically cover crystalline venlafaxine besylate monohydrate, including the racemic form.

Does the patent cover a venlafaxine besylate capsule?

Claim 8 broadly covers a pharmaceutical composition containing venlafaxine besylate and an excipient. A capsule could fall within the broad composition claim if it satisfies the claim language, even though the dependent claims emphasize tablets, pellets, granules, and powder blends.

Is venlafaxine besylate protected by an active US patent?

US 6,717,015 is expired based on its 1999 priority date and approximate September 2020 term end. Separate later patents, if any, must be analyzed independently.

Can a generic company use HPMC in a venlafaxine product?

HPMC use alone does not create infringement. The patent’s HPMC claims require venlafaxine besylate, and some claims also require a tablet, extended release, additional excipients, or a specified dissolution profile.

References

U.S. Patent No. 6,717,015. (2004). Venlafaxine besylate. United States Patent and Trademark Office.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: The Orange Book. FDA.
U.S. Food and Drug Administration. (1997). Effexor NDA 020151 approval history. FDA.
U.S. Food and Drug Administration. (1997). Effexor XR NDA 020699 approval history. FDA.
United States Patent and Trademark Office. (2024). Patent term adjustment and patent term information. USPTO.
United States Code, 35 U.S.C. § 154. (2024). Contents and term of patents; provisional rights.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	039163	⤷ Start Trial
Australia	2003221535	⤷ Start Trial
European Patent Office	1485344	⤷ Start Trial
World Intellectual Property Organization (WIPO)	03082804	⤷ Start Trial
South Africa	200406461	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,717,015

Summary for Patent: 6,717,015