Details for Patent: 10,220,042

Which drugs does patent 10,220,042 protect, and when does it expire?

Patent 10,220,042 protects OXTELLAR XR and is included in one NDA.

This patent has fourteen patent family members in ten countries.

Summary for Patent: 10,220,042

Title:	Modified release preparations containing oxcarbazepine and derivatives thereof
Abstract:	Controlled-release preparations of oxcarbazepine and derivatives thereof for once-a-day administration are disclosed. The inventive compositions comprise solubility- and/or release enhancing agents to provide tailored drug release profiles, preferably sigmoidal release profiles. Methods of treatment comprising the inventive compositions are also disclosed.
Inventor(s):	Padmanabh P. Bhatt, Argaw Kidane, Kevin Edwards
Assignee:	Supernus Pharmaceuticals Inc
Application Number:	US15/834,401
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 10,220,042
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Dosage form;

US Drug Patent 10,220,042: Claim Scope, Oxcarbazepine Formulation Coverage, and Patent Landscape

US Patent No. 10,220,042 covers once-daily oxcarbazepine treatment using a solid homogeneous matrix that contains a pH-dependent polymer designed to promote release in the intestinal environment. The patent is directed primarily to extended-release oxcarbazepine formulations and their therapeutic use, rather than to oxcarbazepine as a molecule.

The strongest commercial relevance is to Oxtellar XR, Supernus Pharmaceuticals' once-daily oxcarbazepine product. The patent creates method-of-treatment exposure for a generic manufacturer whose product is used for seizure treatment and satisfies the specified formulation, dissolution, dose, and pharmacokinetic limitations. It does not, by itself, block every oxcarbazepine formulation or every once-daily product.

What does US Patent 10,220,042 protect?

The independent claim requires all of the following:

1. Treatment of seizures.
2. Administration to a subject in need of treatment.
3. A pharmaceutical formulation administered once daily.
4. Oxcarbazepine as the active ingredient.
5. A solid homogeneous matrix.
6. At least one release-promoting agent.
7. The release-promoting agent must be a polymer with pH-dependent solubility.
8. The polymer must be selected from the listed Markush group.

The central claim is therefore a combination claim. A formulation that contains oxcarbazepine but lacks the specified pH-dependent polymer would not satisfy claim 1. A formulation with the polymer but without a solid homogeneous matrix, or one administered more than once daily, would also fall outside the literal scope of claim 1.

Core technical elements of claim 1

Claim element	Scope
Active ingredient	Oxcarbazepine
Dosage architecture	Solid homogeneous matrix
Release technology	pH-dependent polymer
Administration	Once daily
Therapeutic use	Treatment of seizures
Polymer requirement	Must be selected from the listed group
Claim type	Method of treatment

The listed polymers include cellulose acetate phthalate, cellulose acetate succinate, methylcellulose phthalate, ethylhydroxycellulose phthalate, polyvinyl acetate phthalate, vinyl acetate-maleic anhydride copolymer, styrene-maleic mono-ester copolymer, Eudragit L100-55, and methyl acrylate-methacrylic acid copolymers.

The claim does not require every listed polymer. Each listed polymer is an alternative within the Markush group. A formulation using Eudragit L100-55, for example, can satisfy the polymer limitation without also containing cellulose acetate phthalate.

How do the dependent claims narrow the patent scope?

The dependent claims add formulation, dissolution, pharmacokinetic, dosage-form, and patient limitations.

Claims 2 and 3: Solubility-enhancing agents

Claim 2 requires an additional agent that enhances oxcarbazepine solubility. The categories include:

• Surface-active agents
• Complexing agents
• Cyclodextrins
• pH-modifying agents

Claim 3 narrows the surface-active agent to compounds such as sodium docusate, sodium lauryl sulfate, sodium stearyl fumarate, sorbitan derivatives, and poloxamer-type block copolymers.

These claims provide narrower protection for formulations that combine the pH-dependent release polymer with a solubility-enhancing excipient. They are less likely than claim 1 to read on a generic formulation that uses a different dissolution strategy, but they may be relevant where a generic reproduces the excipient architecture.

Claims 4 and 6-8: Matrix-forming polymers

Claim 4 requires a matrix-forming polymer. Claim 6 identifies broad polymer classes, including:

• Cellulosic polymers
• Alginates
• Gums
• Cross-linked polyacrylic acid
• Carrageenan
• Polyvinylpyrrolidone
• Polyethylene oxides
• Polyvinyl alcohol

Claim 7 narrows the cellulosic category to HPMC, HPC, HEC, methylcellulose, powdered cellulose, cellulose acetate, sodium carboxymethylcellulose, calcium carboxymethylcellulose, and ethylcellulose.

Claim 8 requires the matrix-forming polymer to comprise 1% to 50% by weight of the formulation. These claims create a layered formulation position: the product must contain the pH-dependent release polymer from claim 1 and, for claims 4 through 8, a separate matrix-forming polymer within the specified categories and concentration range.

Claim 5: Dissolution profile

Claim 5 requires that, in vitro:

• 20% to 74% of total oxcarbazepine is released by two hours; and
• 44% to 96% is released by four hours.

This is a functional dissolution limitation. Infringement analysis would depend on the test method, dissolution medium, apparatus, agitation rate, sampling protocol, and interpretation of the release percentages. A product falling outside either range may avoid literal infringement of claim 5 while remaining potentially exposed under claim 1 or other claims.

Claims 9-11: pH-triggered release

Claims 9 through 11 require that the pH-dependent polymer:

• Remain intact below pH 4;
• Dissolve above pH 4 under claim 9;
• Dissolve above pH 5 under claim 10; or
• Dissolve above pH 6 under claim 11.

These limitations are directed to gastroresistant or enteric-type behavior. They distinguish polymers that remain substantially intact in the stomach and dissolve as the dosage form encounters higher intestinal pH.

The claims present potential claim-construction issues around the terms "intact" and "dissolves." The patent does not appear to define those terms solely by a single universal percentage or test condition in the claims. The specification, prosecution history, and expert evidence would be important in litigation.

What formulations and dosage forms are covered?

Claims 12 through 16 regulate excipient categories and concentrations.

Claim	Limitation
12	Release-promoting agent: 10% to 90%; solubility enhancer: 1% to 80%
13	Release-promoting agent: 30% to 70%; solubility enhancer: 1% to 80%
14	Lubricant required
15	Specific wax lubricants listed
16	Lubricant: 0.1% to 20%

Claim 14 identifies conventional lubricants such as magnesium stearate, calcium stearate, zinc stearate, stearic acid, polyethylene glycol, leucine, glyceryl behenate, sodium stearyl fumarate, hydrogenated vegetable oil, and waxes.

Claims 21 through 23 cover pellets, tablets, granules, and capsules, with claims 22 and 23 narrowing the product to tablets containing 600 mg of oxcarbazepine.

A 600 mg once-daily tablet is therefore exposed to the most commercially relevant combination of limitations if it also contains the claimed pH-dependent polymer and matrix system.

What pharmacokinetic and therapeutic outcomes are claimed?

Claims 17 through 19 add active-metabolite and exposure limitations. Oxcarbazepine is converted primarily to its pharmacologically active monohydroxy derivative, commonly referred to as MHD.

Claim	Pharmacokinetic limitation
17	Steady-state MHD blood level of about 2 to 10 µg/mL
18	Minimization of Cmin-to-Cmax fluctuations
19	Cmax about 6 to 10 µg/mL and Cmin about 2 to 5 µg/mL

These claims may be difficult to assess before launch because they require clinical or pharmacokinetic data. A generic manufacturer may have to evaluate whether its product produces the claimed exposure profile after administration. Claims 17 through 19 also raise issues concerning:

• The definition of steady state;
• The blood sampling matrix;
• The assay method;
• The permitted variability around the concentration ranges;
• Whether "minimizing fluctuations" is sufficiently definite;
• Whether the claimed pharmacokinetic result is inherent in a formulation that otherwise satisfies claim 1.

Claims 20 and 23 separately identify 600 mg dosing and 600 mg tablets. Claims 25 and 26 cover epileptic seizures, including partial seizures and generalized tonic-clonic seizures. Claim 27 covers adult and child subjects.

When does US Patent 10,220,042 lose exclusivity?

The patent issued on February 26, 2019. Its effective expiration depends on the earliest effective nonprovisional filing date for the patent family, any patent-term adjustment, terminal disclaimer, and any applicable patent-term extension. The commercially relevant Oxtellar XR patent family has generally been associated with an expiration date in 2027, subject to the specific Orange Book record and any applicable adjustment.

Event	Date or status
Patent issued	February 26, 2019
Patent term basis	20 years from the applicable earliest nonprovisional filing date, subject to adjustment
Commercial product association	Oxtellar XR, extended-release oxcarbazepine
Expected family-level exclusivity period	Generally reported as extending into 2027
NCE exclusivity	Expired before the patent term, because Oxtellar XR was approved in 2012
Generic pathway after patent barriers	ANDA with Paragraph IV or post-expiry certification

The exact enforceable date must be taken from the current USPTO patent record, terminal-disclaimer documentation, and FDA Orange Book listing. A patent's issue date is not its expiration date.

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

Oxtellar XR was approved by the FDA in October 2012 as an extended-release oxcarbazepine tablet for once-daily treatment of partial-onset seizures in adults and children aged six years and older.[1]

Because Oxtellar XR is a small-molecule drug, the relevant competitive pathway is an abbreviated new drug application, not a biosimilar application. FDA-listed patents for the reference product can affect ANDA approval through the Hatch-Waxman certification process under 21 U.S.C. § 355(j).[2]

The Orange Book analysis should distinguish:

• Patents listed for the reference drug;
• Patents in the same formulation family;
• Method-of-use patents;
• Patents that have been delisted, expired, or removed;
• FDA use codes attached to method-of-use listings.

Patent No. 10,220,042 is relevant because its claims are method claims tied to seizure treatment and a specific once-daily formulation. Its practical value depends on whether the patent is listed against the relevant Oxtellar XR presentation and whether the listed use code captures the proposed generic labeling.

Which companies are challenging Oxtellar XR exclusivity?

The principal commercial risk is from ANDA applicants seeking approval for generic extended-release oxcarbazepine tablets. Hatch-Waxman litigation generally begins when the reference-product sponsor receives a Paragraph IV notice alleging that listed patents are invalid, unenforceable, or not infringed.[2]

A Paragraph IV challenge to a formulation patent can target:

• The pH-dependent polymer limitation;
• The solid homogeneous matrix limitation;
• The dissolution profile;
• The 600 mg dosage limitation;
• The pharmacokinetic limitations;
• Obviousness based on prior extended-release oxcarbazepine and enteric-release technology;
• Written description and enablement;
• Indefiniteness of functional terms such as "minimizing fluctuations."

The available claim text does not identify a specific ANDA applicant, litigation docket, settlement agreement, or launch date. The Orange Book and federal court docket should control any current determination of which manufacturers have issued Paragraph IV notices or entered litigation.

What patent litigation and settlement issues affect generic entry?

The key litigation question is whether a proposed generic can avoid every asserted claim while maintaining bioequivalence and FDA approval.

Likely design-around strategies

A generic applicant could attempt to:

1. Use a release-control polymer outside the listed Markush group.
2. Use a multiparticulate or osmotic system that does not form a solid homogeneous matrix.
3. Use a pH-independent release mechanism.
4. Avoid the claimed solubility-enhancing agents.
5. Alter the dissolution profile so it falls outside claim 5.
6. Avoid a 600 mg tablet presentation.
7. Use a different dosage schedule, although that may conflict with the reference-product labeling.
8. Challenge the validity of the claims rather than redesign the product.

Each approach has regulatory consequences. A formulation that is materially different from Oxtellar XR may create difficulty demonstrating pharmaceutical equivalence or bioequivalence. A design-around that changes the labeled dosing regimen may also be commercially unattractive.

A settlement agreement could include a license, an agreed generic entry date, a covenant not to sue, or restrictions on authorized generic supply. No settlement terms should be inferred from the patent claims alone.

How strong is the patent estate for once-daily oxcarbazepine?

The patent has moderate-to-strong product-specific coverage but limited molecule-wide coverage.

Strengths

• Claim 1 combines active ingredient, dosage frequency, matrix architecture, polymer chemistry, and seizure treatment.
• The claims cover multiple polymer classes and formulation excipients.
• Claims 17 through 19 add pharmacokinetic protection that can support a commercial extended-release profile.
• Claims 20 through 23 target the commercially important 600 mg tablet.
• The claim set includes both structural and functional limitations.

Weaknesses

• The claims do not cover oxcarbazepine generally.
• The pH-dependent polymer must come from a defined list.
• The claim requires a solid homogeneous matrix, potentially excluding alternative delivery systems.
• Dissolution and pharmacokinetic claims may depend on testing conditions and reproducibility.
• Method claims require proof that the accused product is administered for the claimed seizure indication.
• Several dependent claims have overlapping or cumulative limitations, narrowing their practical reach.

The patent is stronger against a generic that closely reproduces the reference-product formulation than against a materially different extended-release system.

How does this patent compare with molecule, formulation, and method-of-use patents?

Patent category	Typical protection	Relevance to US 10,220,042
Compound patent	Oxcarbazepine molecule	Not the focus
Composition patent	Ingredients and dosage form	Covered indirectly through method claims
Formulation patent	Matrix, excipients, release profile	Central technical subject
Method-of-use patent	Treating seizures	Expressly required
Pharmacokinetic patent	Blood-level or exposure profile	Claims 17-19
Manufacturing patent	Granulation, compression, coating, process controls	Not expressly claimed in the supplied claims

The patent does not provide a broad manufacturing-process barrier. A manufacturer may use a different granulation, coating, compression, or scale-up process if the finished product does not satisfy the claimed formulation and treatment limitations.

What generic launch risks exist?

Generic entry risk is concentrated in the period after patent expiry or after a successful Paragraph IV challenge. The main scenarios are:

Launch scenario	Commercial effect
Patent survives through expected expiry	Generic launch delayed until expiry or licensed date
Court finds noninfringement	Earlier launch possible
Court invalidates key claims	Earlier launch possible
Settlement permits licensed entry	Entry occurs on negotiated terms
Authorized generic launch	Price erosion may begin before independent generic entry
Formulation design-around	Entry depends on FDA equivalence and commercial viability

The absence of biosimilar risk does not eliminate competitive risk. Oxcarbazepine is a small molecule, so multiple ANDA applicants can potentially enter once the patent and regulatory barriers are removed.

What geographic coverage does the patent provide?

US Patent No. 10,220,042 provides rights only in the United States. It does not establish protection in Europe, Canada, Japan, or other markets. Geographic exposure must be evaluated through corresponding national patents and applications, including:

• European Patent Office family members;
• Canadian patents;
• Japanese patents;
• Australian patents;
• Other national phase filings.

The US claims also do not automatically establish freedom to operate for international manufacture. A manufacturer located outside the United States may face separate process, formulation, or use patents in the country of manufacture or sale.

Key Takeaways

• US Patent 10,220,042 is a formulation-linked method-of-treatment patent for once-daily oxcarbazepine.
• Claim 1 requires oxcarbazepine, a solid homogeneous matrix, a listed pH-dependent polymer, once-daily administration, and seizure treatment.
• The dependent claims add solubility enhancers, matrix polymers, excipient concentrations, dissolution ranges, pH thresholds, MHD exposure, 600 mg dosing, tablets, and seizure subtypes.
• The patent is commercially associated with Oxtellar XR and is part of the patent barrier relevant to generic extended-release oxcarbazepine.
• The family-level exclusivity period is generally associated with 2027, subject to the current USPTO and Orange Book records.
• Generic risk is higher for products that closely reproduce the Oxtellar XR formulation and lower for products using a different release technology.
• There is no biosimilar pathway because oxcarbazepine is a small-molecule active ingredient.
• Patent No. 10,220,042 does not provide broad protection over oxcarbazepine, all once-daily formulations, or all manufacturing processes.

FAQs

Does US Patent 10,220,042 cover immediate-release Trileptal?

No. The claims require a once-daily formulation in a solid homogeneous matrix with a specified pH-dependent release-promoting polymer. Immediate-release oxcarbazepine products do not inherently satisfy those limitations.

Can a generic avoid infringement by using a different enteric polymer?

Potentially. A polymer outside the listed Markush group may avoid literal infringement of claim 1, but the product must still be evaluated against the full claim set, equivalents doctrine, FDA equivalence requirements, and other Oxtellar XR patents.

Does a 600 mg dose automatically infringe the patent?

No. A 600 mg dose is only one limitation in claims 20 and 23. The product must also satisfy the applicable formulation, polymer, matrix, administration, and treatment limitations.

Are claims 17 through 19 composition claims?

No. They are dependent method claims that add blood-level and pharmacokinetic requirements to the once-daily seizure-treatment method.

Is a Paragraph IV certification required for every generic oxcarbazepine product?

No. The certification depends on the patents listed for the specific reference drug, the proposed labeling, the ANDA applicant's patent position, and whether the applicant seeks approval before the listed patent expiration dates.

References

1. U.S. Food and Drug Administration. (2012). Oxtellar XR prescribing information. FDA.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
3. U.S. Patent and Trademark Office. (2019). U.S. Patent No. 10,220,042: Oxcarbazepine formulations and methods of use.
4. United States Code. (2023). 21 U.S.C. § 355: New drugs.
5. United States Code. (2023). 35 U.S.C. § 154: Contents and term of patent; provisional rights.

Drugs Protected by US Patent 10,220,042

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Supernus Pharms	OXTELLAR XR	oxcarbazepine	TABLET, EXTENDED RELEASE;ORAL	202810-001	Oct 19, 2012	AB	RX	Yes	No	10,220,042					TREATMENT OF PARTIAL-ONSET SEIZURES
Supernus Pharms	OXTELLAR XR	oxcarbazepine	TABLET, EXTENDED RELEASE;ORAL	202810-002	Oct 19, 2012	AB	RX	Yes	No	10,220,042					TREATMENT OF PARTIAL-ONSET SEIZURES
Supernus Pharms	OXTELLAR XR	oxcarbazepine	TABLET, EXTENDED RELEASE;ORAL	202810-003	Oct 19, 2012	AB	RX	Yes	Yes	10,220,042					TREATMENT OF PARTIAL-ONSET SEIZURES

International Family Members for US Patent 10,220,042

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	E496623
Australia	2007242984
Canada	2597740
China	101489560
Germany	602007012236
European Patent Office	2026815