Details for Patent: 7,829,120

Which drugs does patent 7,829,120 protect, and when does it expire?

Patent 7,829,120 protects OLEPTRO and is included in one NDA.

This patent has forty-six patent family members in twenty-five countries.

Summary for Patent: 7,829,120

Title:	Trazodone composition for once a day administration
Abstract:	The invention relates to a once a day formulation of trazodone or a trazodone derivative. The formulation contains trazodone or a trazodone derivative and a controlled release excipient so that, once administered orally, the trazodone or the trazodone derivative is maintained at a therapeutic plasma concentration from at least 1 hour to at least 24 hours after initial administration. After administration, the initial therapeutic action takes effect within the first hour and lasts at least about 24 hours. This therapeutic effect remains relatively and substantially stable for the remaining period of 24 hours. The formulations can be used for treating depression and/or sleeping disorders.
Inventor(s):	Sonia Gervais, Damon Smith, Miloud Rahmouni, Pauline Contamin, Rachid Ouzerourou, My Linh Ma, Angela Ferrada, Fouzia Soulhi
Assignee:	Angelini Pharma Inc
Application Number:	US11/519,194
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Delivery; Dosage form;

US Patent 7,829,120: Trazodone Extended-Release Composition, Claim Scope, Expiration, and Generic Risk

US Patent 7,829,120 protects an oral, once-daily sustained-release trazodone formulation built around a high-amylose starch and hydroxypropylmethylcellulose matrix. Its strongest protection is composition-based: a product must combine trazodone or a trazodone derivative with specified excipient classes and satisfy a plasma-release profile. Dependent claims narrow protection to 150 mg and 300 mg trazodone hydrochloride tablets, gelatinized cross-linked starch, bedtime dosing, sleep-disorder treatment, depression treatment, and reduced morning drowsiness. The patent was associated with the extended-release trazodone product Oleptro and is no longer a meaningful long-term barrier to US generic entry after expiration of its patent term.[1-4]

What does US Patent 7,829,120 protect?

The patent protects a sustained-release pharmaceutical composition for once-daily oral administration. Claim 1 requires the following formulation architecture:

Component	Claimed amount by weight
Trazodone or derivative	About 20% to about 50%
Cross-linked high-amylose starch	About 20% to about 50%
Hydroxypropylmethylcellulose	About 10% to about 25%
Cetylpyridinium chloride	0% to about 5%
Alginic acid	0% to about 20%
Sodium stearyl fumarate	About 1% to about 5%
Colloidal silicon dioxide	Up to about 1%

The composition must release trazodone to maintain a substantially constant effective plasma concentration of approximately 50 ng/mL to 3,000 ng/mL from at least about one hour through at least about 24 hours after administration.[1]

The claim is cumulative. A potentially infringing product would generally need to satisfy the required ingredient ranges, the sustained-release function, and the pharmacokinetic limitation. A formulation that uses trazodone but omits the claimed high-amylose starch or falls outside the specified excipient structure would have a substantial noninfringement position against literal infringement of claim 1.

How many independent claims does US Patent 7,829,120 contain?

The issued claims contain three principal independent claim groups:

1. Claim 1: pharmaceutical composition.
2. Claim 18: method of treating a sleeping disorder.
3. Claim 21: method of treating depression.

Claim 23 is formally dependent on claim 1 and clarifies that the trazodone derivative is trazodone hydrochloride. The remaining claims narrow the formulation, dose, dosage form, patient population, treatment setting, pharmacokinetic profile, or therapeutic result.[1]

Composition claims

Claim 1 is the central formulation claim. Claims 4 through 17 add specific commercial and technical limitations, including:

• 150 mg trazodone hydrochloride;
• 300 mg trazodone hydrochloride;
• 35% to 50% trazodone hydrochloride;
• high-amylose starch containing approximately 65% to 75% amylose;
• phosphorus oxychloride cross-linking;
• hydroxypropyl side chains;
• gelatinization;
• human administration;
• tablet and caplet dosage forms;
• bedtime administration; and
• reduced drowsiness approximately eight hours after dosing compared with repeated immediate-release trazodone.

These claims concentrate protection around the commercial extended-release tablet rather than every possible sustained-release trazodone dosage form.

Method-of-treatment claims

Claims 18 through 22 cover administration of the claimed formulation to treat sleep disorders or depression. The sleep-related claims include improvement of sleep architecture and administration before bedtime. The depression claims require once-daily administration and also identify bedtime dosing.

Method claims can remain relevant even when a formulation claim is challenged, but their practical enforcement depends on labeling, physician prescribing behavior, pharmacy substitution, and proof of the claimed therapeutic use.

What formulations are protected by the patent?

The patent covers a hydrophilic and polysaccharide matrix system. The high-amylose starch provides a cross-linked, water-responsive structural component. Hydroxypropylmethylcellulose contributes gel formation and diffusion control. Sodium stearyl fumarate functions as a lubricant, while alginic acid, cetylpyridinium chloride, and colloidal silicon dioxide are optional or limited components within the claimed ranges.

The narrower starch claims are technically important. Claims 9 through 11 require starch with approximately 65% to 75% amylose, phosphorus oxychloride cross-linking, hydroxypropyl side chains, and gelatinization. A competing product may avoid those narrower claims by using a different polymer, a non-cross-linked starch, a different cross-linking chemistry, or a high-amylose material outside the claimed composition.

Are the percentages calculated on the whole dosage unit?

The claims use weight percentages for the composition. In an infringement analysis, the relevant denominator would ordinarily be the total claimed pharmaceutical composition, subject to claim construction and the product’s manufacturing records. Small changes in excipient quantity may not avoid infringement if they remain within an “about” range. A formulation outside a numerical range may still create a doctrine-of-equivalents issue, although prosecution history, prior art, and the significance of the selected range would control.

Does the patent cover 150 mg and 300 mg trazodone tablets?

Yes. Claim 4 narrows the composition to 150 mg trazodone hydrochloride. Claim 6 narrows it to 300 mg. Claims 5 and 7 add one-hour plasma concentration ranges:

Dosage	One-hour plasma concentration
150 mg	About 150 ng/mL to about 500 ng/mL
300 mg	About 300 ng/mL to about 1,000 ng/mL

Claims 13 through 15 narrow the dosage form to a tablet or caplet and specifically identify a caplet containing approximately 300 mg trazodone. These claims correspond closely to the commercial profile of Oleptro, a once-daily extended-release trazodone hydrochloride product.[2]

What is the FDA and Orange Book status of the patent?

Oleptro was approved by the FDA as an extended-release trazodone hydrochloride tablet for major depressive disorder. The product was associated with Angelini Pharma and marketed in 150 mg and 300 mg strengths.[2,3]

The FDA Orange Book has historically identified US Patent 7,829,120 in connection with the extended-release trazodone product. Orange Book listing creates a statutory patent-certification issue for an ANDA applicant, but it does not independently establish patent validity or infringement.[3]

An ANDA applicant seeking approval before patent expiry could certify under Paragraph IV that the listed patent was invalid, unenforceable, or would not be infringed. The applicant would then need to provide notice to the patent owner and NDA holder. A timely infringement action could trigger a 30-month stay of approval under the Hatch-Waxman framework.[5]

When did US Patent 7,829,120 lose exclusivity?

The patent’s enforceable term was tied to the statutory patent term calculated from its relevant nonprovisional or international filing history, subject to any patent-term adjustment and applicable pediatric extension. Public patent records identify the patent as a 2010 grant with a term ending in the mid-2020s.[1]

The key commercial point is that US Patent 7,829,120 does not provide a current long-duration exclusivity barrier. Any remaining regulatory exclusivity, later-issued patent, or separately listed patent must be evaluated independently from this patent.

FDA approval of a branded product also does not prevent approval of an ANDA after applicable patents and exclusivities have expired. Immediate-release trazodone has long been available generically, while extended-release trazodone requires a separate demonstration of pharmaceutical equivalence and bioequivalence.

Were Paragraph IV challenges filed against the patent?

The existence of an ANDA certification cannot be inferred solely from the Orange Book listing. FDA does not publish every certification detail in a consolidated public litigation database, and patent litigation records must be checked by defendant, patent number, NDA, and product.

For business purposes, the relevant risk categories are:

Challenge type	Effect
Paragraph III certification	ANDA approval deferred until patent expiry
Paragraph IV certification	Potential patent litigation and 30-month stay
Section viii statement	Applicant omits a patented method of use from labeling
Post-expiry ANDA	No patent-based approval delay from the expired patent

A generic applicant could challenge the composition claims through a Paragraph IV certification or attempt to design around the excipient matrix and file without creating infringement exposure. Method-of-use claims may be addressed through a section viii labeling carve-out if the approved generic label excludes the patented use and the remaining label supports approval.[5]

What patent litigation affects trazodone extended-release products?

US Patent 7,829,120 should be analyzed together with the full Orange Book record for the relevant trazodone extended-release NDA and any continuation, divisional, or related formulation patent. The patent number alone does not establish that it was the only enforceable patent protecting Oleptro.

The principal litigation questions are:

• whether the accused formulation contains cross-linked high-amylose starch;
• whether the excipients fall within the claimed percentage ranges;
• whether the product meets the plasma-concentration limitation;
• whether “substantially constant” is definite and technically satisfied;
• whether the claims are enabled across the full concentration and composition ranges;
• whether prior art disclosed trazodone in a starch/HPMC sustained-release matrix; and
• whether prosecution history limits the scope of “about” or the functional release language.

No biosimilar pathway applies. Trazodone hydrochloride is a small-molecule drug, so competition proceeds through the ANDA pathway rather than the Biologics Price Competition and Innovation Act pathway.[5,6]

How strong is the patent estate for trazodone extended release?

The estate is strongest against products that copy the commercial formulation architecture:

• trazodone hydrochloride as the active ingredient;
• 150 mg or 300 mg strength;
• tablet or caplet format;
• cross-linked high-amylose starch;
• HPMC as a matrix former;
• once-daily dosing;
• approximately 24-hour release; and
• bedtime use.

It is weaker against formulations that use a different controlled-release mechanism. Examples include osmotic systems, multiparticulate beads, lipid matrices, coated pellets, ion-exchange systems, or alternative cellulose and polysaccharide combinations.

Claim-strength assessment

Claim area	Relative enforcement value	Main vulnerability
Claim 1 composition	High against close copies	Prior-art combination and functional-language challenges
Claims 4 and 6 dosage strengths	Moderate	Narrow scope and possible design-around
Claims 9-11 starch chemistry	Moderate to high if copied	Alternative starch chemistry
Claims 13-15 tablet/caplet	Moderate	Dosage-form limitation
Claims 16-17 bedtime and reduced drowsiness	Lower	Proof of comparative clinical effect
Claims 18-22 treatment methods	Moderate	Labeling and divided-infringement issues
Claim 23 trazodone hydrochloride	Narrow clarification	Does not independently broaden claim 1

The broadest commercial exposure arises from claim 1. The narrower claims improve fallback positions but reduce the number of products they can reach.

How does Oleptro compare with immediate-release trazodone?

Attribute	Extended-release trazodone	Immediate-release trazodone
Typical dosing concept	Once daily	Divided or repeated dosing
Matrix technology	Sustained-release polymer/starch system	Immediate-release tablet
Commercial product	Oleptro	Desyrel and generic trazodone
Patent relevance	Formulation and method claims	Older composition and use history
Generic pathway	ANDA demonstrating ER equivalence	Established generic market
Main clinical rationale	Longer exposure and bedtime administration	Flexible dosing and rapid release

The patent does not prevent generic manufacture of conventional immediate-release trazodone. Its commercial relevance is limited to products that seek to replicate the extended-release profile and associated labeling.

What generic launch scenarios exist?

Scenario 1: Direct extended-release copy

A generic manufacturer uses substantially the same excipient system and seeks approval for 150 mg and 300 mg tablets. This creates the highest claim risk and would likely require a detailed Paragraph IV analysis if the patent remained unexpired.

Scenario 2: Formulation design-around

The applicant uses a different release-control technology or excludes one or more required matrix components. This reduces literal infringement risk but requires bioequivalence evidence for the extended-release dosage form.

Scenario 3: Labeling carve-out

The applicant omits a patented sleep-disorder indication or other method-of-use language while retaining an unpatented indication. This strategy may address method claims but does not avoid a composition claim covering the product itself.

Scenario 4: Post-expiry launch

After expiration of the relevant patent and any enforceable related patents, the applicant can launch subject to FDA approval, exclusivity, and any applicable settlement restrictions. The principal commercial risk then becomes substitution, manufacturing scale, and market demand rather than patent enforcement.

What manufacturing and geographic barriers remain?

The patent is a US right. It does not directly block manufacture, sale, or use outside the United States. Foreign protection would depend on corresponding national patents and their individual status.

Manufacturing barriers may persist even after patent expiry. A generic company must reproduce the release profile consistently, control starch cross-linking and gelatinization where relevant, meet dissolution specifications, and demonstrate bioequivalence under FDA requirements. Those technical requirements can delay entry without creating patent exclusivity.

The most important process risks involve:

• variability in high-amylose starch properties;
• hydration and gel formation;
• tablet compression;
• dissolution performance across pH conditions;
• dose proportionality between 150 mg and 300 mg strengths; and
• food-effect and steady-state pharmacokinetics.

What revenue exposure did the patent create?

US Patent 7,829,120 was commercially relevant to Oleptro revenue because it covered the formulation rather than trazodone generally. Its value depended on the size of the extended-release segment, the number of approved ANDA competitors, the timing of patent expiry, and the presence of additional listed patents.

The patent did not protect the large preexisting generic immediate-release trazodone market. Revenue exposure therefore centered on branded extended-release prescriptions and any price premium associated with once-daily dosing, bedtime administration, and reduced next-day sedation claims.

Key Takeaways

• US Patent 7,829,120 is a formulation patent for once-daily sustained-release trazodone.
• Claim 1 requires trazodone or a derivative, cross-linked high-amylose starch, HPMC, specified excipient ranges, and a sustained plasma-release profile.
• Claims 4 and 6 specifically cover 150 mg and 300 mg trazodone hydrochloride compositions.
• Claims 9 through 11 protect particular high-amylose starch characteristics, including phosphorus oxychloride cross-linking and gelatinization.
• Claims 18 through 22 cover treatment of sleep disorders and depression with the claimed formulation.
• The patent was associated with Oleptro, an FDA-approved extended-release trazodone product.
• The patent’s enforceable term ended in the mid-2020s, eliminating it as a durable present-day barrier by itself.
• Generic risk depends on the complete Orange Book record, related patents, ANDA certifications, and any litigation or settlement agreements.
• A formulation design-around remains technically feasible through alternative controlled-release systems.
• No biosimilar pathway applies because trazodone is a small-molecule drug.

FAQs

Is US Patent 7,829,120 a patent on trazodone itself?

No. It does not claim trazodone as a molecule. It claims specified sustained-release compositions and methods using those compositions.

Does the patent cover all extended-release trazodone tablets?

No. The broadest claim is limited by its ingredient categories, percentage ranges, and release profile. An extended-release product using a materially different matrix may avoid literal infringement.

Can a generic manufacturer sell immediate-release trazodone despite this patent?

Yes. The patent targets sustained-release formulations and does not block conventional immediate-release trazodone products.

Does a 300 mg trazodone tablet automatically infringe the patent?

No. Dose strength alone is insufficient. The product must also satisfy the applicable composition and release limitations.

Are sleep-disorder claims commercially important after patent expiration?

They may remain relevant to historical infringement analysis, but they do not restore exclusivity once the enforceable patent term has ended. Current competition depends on other patents, FDA exclusivity, labeling, and product approval status.

References

1. United States Patent and Trademark Office. (2010). US Patent No. 7,829,120, sustained release formulations of trazodone.
2. U.S. Food and Drug Administration. (2010). Oleptro (trazodone hydrochloride) extended-release tablets: Prescribing information.
3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book.
4. National Library of Medicine. (n.d.). DailyMed: Oleptro trazodone hydrochloride extended-release tablets.
5. U.S. Food and Drug Administration. (2017). Abbreviated new drug application regulations and patent certification requirements.
6. U.S. Food and Drug Administration. (2024). Biosimilar biological products and the Biologics Price Competition and Innovation Act.

Drugs Protected by US Patent 7,829,120

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Angelini Pharma	OLEPTRO	trazodone hydrochloride	TABLET, EXTENDED RELEASE;ORAL	022411-001	Feb 2, 2010		DISCN	Yes	No	7,829,120		Y			METHOD OF TREATING DEPRESSION
Angelini Pharma	OLEPTRO	trazodone hydrochloride	TABLET, EXTENDED RELEASE;ORAL	022411-002	Feb 2, 2010		DISCN	Yes	No	7,829,120		Y			METHOD OF TREATING DEPRESSION

International Family Members for US Patent 7,829,120

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	059678
Argentina	059682
Argentina	109571
Australia	2006308448
Australia	2006308449