Details for Patent: 8,821,930

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Which drugs does patent 8,821,930 protect, and when does it expire?

Patent 8,821,930 protects OXTELLAR XR and is included in one NDA.

This patent has fourteen patent family members in ten countries.

Summary for Patent: 8,821,930

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:	US14/103,103
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,821,930
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Compound; Dosage form;

United States Drug Patent 8,821,930: Claims, Scope, Expiration, Litigation, and Oxcarbazepine Patent Landscape

U.S. Patent No. 8,821,930 protects once-daily oxcarbazepine formulations based on a homogeneous matrix, a solubility-enhancing agent, and a pH-dependent release-promoting polymer. The claim set is directed to dosage-form architecture and pharmacokinetic performance rather than oxcarbazepine itself. The patent is associated with Oxtellar XR, Supernus Pharmaceuticals’ extended-release oxcarbazepine product. Its principal infringement risk concerns generic extended-release tablets using the same matrix, solubility-enhancement, and delayed-release polymer combination.

What does U.S. Patent 8,821,930 cover?

The patent covers a pharmaceutical formulation for once-daily administration of oxcarbazepine. Independent claim 1 requires all of the following elements:

Required element	Claim limitation
Active ingredient	Oxcarbazepine
Dosage form architecture	Homogeneous matrix
Matrix-forming polymer	1% to 50% by weight
Solubility-enhancing agent	1% to 80% by weight
Release-promoting agent	10% to 90% by weight
Release-promoting polymer	pH-dependent solubility
Polymer function	Intact below pH 4 and dissolves above pH 4
Administration	Once daily

The release-promoting polymer must be selected from a defined group that includes cellulose acetate phthalate, cellulose acetate succinate, polyvinyl acetate phthalate, Eudragit L100-55, and related methacrylic acid copolymers.[1]

The claim is a combination claim. A formulation that contains oxcarbazepine and an extended-release matrix but lacks the claimed pH-dependent polymer would not literally satisfy claim 1. The same applies if the formulation uses a pH-dependent polymer but does not contain the claimed matrix-forming polymer or solubility-enhancing agent.

How broad are the claims of Patent 8,821,930?

The claims are broad in ingredient selection but narrower in formulation structure and quantitative composition.

Ingredient breadth

The patent claims multiple classes of matrix-forming polymers, including:

• HPMC;
• HPC;
• HEC;
• methylcellulose;
• ethylcellulose;
• sodium carboxymethylcellulose;
• alginates;
• gums;
• cross-linked polyacrylic acid;
• carrageenan;
• polyvinylpyrrolidone;
• polyethylene oxides; and
• polyvinyl alcohol.

The solubility-enhancing component is also broadly defined. Claim 4 covers surface-active agents, complexing agents, cyclodextrins, pH-modifying agents, and hydration-promoting agents. Claim 5 expressly identifies sodium docusate, sodium lauryl sulfate, sodium stearyl fumarate, sorbitan esters, poloxamers, and combinations.

The release-promoting polymer list is narrower. It is limited to specified pH-dependent polymers, although claim interpretation may extend to pharmaceutically equivalent materials within the listed chemical classes.

Quantitative breadth

Claim 1 permits:

• 1% to 50% matrix-forming polymer;
• 1% to 80% solubility-enhancing agent; and
• 10% to 90% pH-dependent release-promoting agent.

These ranges overlap substantially with ordinary formulation practice. A generic developer may therefore face difficulty designing around the numerical limitations without changing the release mechanism or dosage-form structure.

The ranges are open-ended only to the extent permitted by the claim language. A formulation outside any required range may avoid literal infringement, but a court would assess whether the difference is insubstantial under the doctrine of equivalents.

Pharmacokinetic limitations

Claims 14 through 16 add pharmacokinetic results for the monohydroxy derivative of oxcarbazepine, commonly referred to as MHD. The claimed outcomes include:

• steady-state MHD concentrations of approximately 2 to 10 micrograms per milliliter;
• reduced fluctuation between Cmin and Cmax;
• Cmax of approximately 6 to 10 micrograms per milliliter; and
• Cmin of approximately 2 to 5 micrograms per milliliter.

These claims may be difficult to enforce based solely on blood-level results unless the accused product reproducibly produces the claimed pharmacokinetic profile. They also create evidentiary issues involving study design, patient population, dose administration, bioequivalence, and analytical variability.

Which dependent claims matter commercially?

Claims 17 through 20 are commercially important because they narrow the formulation to a 600-milligram strength and, ultimately, to 600-milligram tablets.

Claim	Added limitation	Commercial relevance
17	600 mg of oxcarbazepine	Targets a principal Oxtellar XR strength
18	Pellets, tablets, granules, or capsules	Covers multiple dosage forms
19	Tablets	Relevant to conventional generic tablet products
20	Each tablet contains 600 mg	Directly relevant to a 600-mg tablet launch

A generic product containing 600 mg of oxcarbazepine in a tablet could face claims 1, 17, 19, and 20 if it also uses the claimed polymer system and ingredient ranges.

Claims 2 through 13 provide additional fallback positions. They are especially relevant if a court narrows claim 1 or finds one broad element insufficiently supported.

What formulations are protected by Patent 8,821,930?

The patent protects matrix tablets and related dosage forms that combine extended release with pH-triggered release promotion.

A representative claimed formulation would contain:

• oxcarbazepine;
• HPMC or another hydrophilic matrix polymer;
• a surfactant or hydration-promoting agent;
• Eudragit L100-55 or a comparable listed pH-dependent polymer; and
• optional lubricant.

Claim 9 further covers formulations with a sigmoidal in-vitro release profile. This limitation is technically important because it points to a release sequence in which drug release is relatively limited during an initial period, increases after the pH-dependent polymer dissolves, and then proceeds through matrix-controlled release.

Claim 6 requires the pH-dependent polymer to remain intact below pH 4 and dissolve above pH 4. Claims 7 and 8 raise the dissolution threshold to above pH 5 and above pH 6. These limitations correspond to gastrointestinal pH transitions and support delayed or staged oxcarbazepine release.

The patent does not require a particular coating process, compression force, excipient manufacturing method, tablet shape, or dissolution apparatus in the claims provided. A product can therefore fall within the claims even if it is manufactured using a process materially different from the examples, provided the final formulation satisfies the structural and compositional limitations.

What is the Orange Book status of Patent 8,821,930?

Patent 8,821,930 has been listed in connection with Oxtellar XR, NDA 201753, an extended-release oxcarbazepine tablet approved by the FDA.[2] Oxcarbazepine is an established small-molecule active ingredient, so the relevant regulatory protection is based on the new dosage form and associated patent estate rather than new chemical entity exclusivity.

Regulatory item	Status
Product	Oxtellar XR
Active ingredient	Oxcarbazepine
Dosage form	Extended-release tablets
NDA	201753
Sponsor	Supernus Pharmaceuticals, Inc.
Patent	U.S. 8,821,930
Patent subject	Once-daily oxcarbazepine formulation
Regulatory pathway for competitors	ANDA
Biosimilar pathway	Not applicable

The FDA’s three-year exclusivity for a new dosage form does not permanently block an ANDA based on a Paragraph IV certification. Patent protection, rather than the three-year exclusivity period, has been the principal barrier for generic entry.[2]

When does Patent 8,821,930 lose exclusivity?

The reported Orange Book expiration date for U.S. Patent 8,821,930 is November 7, 2027.[2] The effective market-protection date can be affected by patent-term adjustment, patent-term extension, pediatric exclusivity, litigation stays, and later-issued continuation patents.

The patent should be assessed as part of a family rather than in isolation. A generic applicant may challenge the ’930 patent while also addressing continuation or related patents that claim narrower formulations, dosage strengths, dissolution profiles, or methods of treatment.

Event	Approximate significance
Priority filing	November 2005
Patent grant	September 2014
FDA approval of Oxtellar XR	2012
Reported ’930 patent expiration	November 7, 2027
Generic approval timing	Dependent on ANDA certification, litigation, and any applicable stay

The patent’s expiration does not automatically establish the earliest lawful generic launch date. A settlement agreement, later patent, injunction, or regulatory exclusivity period can alter market entry.

Which companies have challenged the Oxtellar XR patent estate?

The principal reported litigation involved Supernus Pharmaceuticals and TWi Pharmaceuticals. The dispute concerned generic oxcarbazepine extended-release products and Supernus patents covering Oxtellar XR technology, including U.S. Patent No. 8,821,930 and related patents.[3]

Generic challenges in this area generally proceed through a Paragraph IV certification. The ANDA applicant asserts that the listed patent is invalid, unenforceable, or not infringed. The branded company may then file an infringement action under the Hatch-Waxman Act, triggering a statutory stay of FDA approval for up to 30 months, subject to court rulings and statutory exceptions.[4]

The relevant competitive parties include:

• Supernus Pharmaceuticals, the Oxtellar XR sponsor and patent holder;
• TWi Pharmaceuticals, a reported ANDA challenger;
• other generic manufacturers that may pursue oxcarbazepine extended-release tablets after patent expiry or through separate patent certifications; and
• distributors and contract manufacturers whose products may be supplied under a generic applicant’s ANDA.

The existence of an ANDA challenge does not establish that a generic product can launch. The outcome depends on claim construction, infringement evidence, validity defenses, settlement terms, and FDA approval status.

What patent litigation affects Oxtellar XR?

The main litigation issues for the ’930 patent are likely to be:

Infringement

An accused generic product would be evaluated against each limitation of the asserted claim. Key questions include:

1. Whether the generic uses a homogeneous matrix.
2. Whether the matrix polymer falls within the claimed percentage range.
3. Whether its excipients function as solubility-enhancing agents.
4. Whether its release-promoting polymer is one of the listed pH-dependent polymers.
5. Whether the polymer remains intact below pH 4 and dissolves above the claimed pH threshold.
6. Whether a 600-mg tablet satisfies claims 17, 19, and 20.

A generic applicant may attempt to characterize an excipient as a processing aid rather than a solubility-enhancing agent. Functional claim construction would make that strategy fact-dependent.

Validity

Potential validity defenses include:

• anticipation based on prior extended-release oxcarbazepine formulations;
• obviousness based on combining matrix technology with enteric polymers;
• lack of written description for the full percentage ranges;
• lack of enablement across the full list of polymers and excipients; and
• indefiniteness involving “homogeneous matrix,” “sigmoidal” release, or functional dissolution language.

The patent’s validity strength is higher for narrow embodiments supported by examples and lower for combinations at the outer edges of the claimed ranges. The broad genus of excipients and polymers creates a potential written-description and enablement pressure point.

Enforceability

The claim set does not, on its face, indicate an unusual enforceability issue. Enforceability disputes would ordinarily focus on inequitable conduct, inventorship, disclosure obligations, prosecution representations, or prior-art handling.

How strong is the patent estate for Oxtellar XR?

The ’930 patent has meaningful commercial strength because it combines three barriers:

1. a matrix-controlled extended-release structure;
2. a pH-dependent release component; and
3. a once-daily pharmacokinetic objective.

The patent is less exposed than a claim directed only to a dosage amount or a single excipient. A generic product would need to avoid the claimed formulation combination or accept an infringement position.

Its principal weaknesses are claim breadth and functional language. The patent covers numerous polymers and solubility agents, but broad alternatives can create validity challenges. Claims 17 through 20 are stronger from an infringement perspective when the generic product matches the 600-mg tablet strength, although they are narrower and easier to avoid through different strengths or dosage forms.

Relative strength by claim group

Claim group	Scope	Relative enforcement value
Claim 1	Broad combination formulation	High commercial reach; validity exposure
Claims 2-5	Specific polymer and solubility-agent classes	Useful fallback claims
Claims 6-8	pH-triggered dissolution thresholds	Technically specific
Claim 9	Sigmoidal release	Testing-dependent
Claims 10-13	Amounts and lubricants	Secondary formulation coverage
Claims 14-16	MHD pharmacokinetics	Difficult proof but potentially valuable
Claims 17-20	600-mg tablets	Strong product targeting; narrow scope

What generic launch risks exist?

A generic launch before the reported November 2027 expiration date would face several scenarios.

Launch scenario	Risk profile
Paragraph III certification	Delayed launch until patent expiry
Paragraph IV certification with litigation	Possible 30-month FDA stay and infringement trial
Non-infringing formulation	Requires avoiding at least one required claim element
Successful invalidity defense	Early launch possible, subject to other patents
Settlement launch	Entry date depends on confidential or court-filed terms
At-risk launch	Exposure to damages, injunction, and lost profits claims

The most practical design-around options are:

• replacing the listed pH-dependent polymer with a nonlisted polymer;
• eliminating the homogeneous matrix architecture;
• using a multiparticulate or coated-pellet system that does not meet the matrix limitation;
• changing the release mechanism so the pH-dependent polymer is not a release-promoting agent;
• formulating outside the claimed percentage ranges; or
• using a dosage strength other than 600 mg.

Each option has technical and regulatory consequences. A design-around that changes dissolution behavior may fail FDA bioequivalence requirements even if it reduces patent risk.

Are biosimilar risks relevant to oxcarbazepine?

No. Oxcarbazepine is a synthetic small-molecule drug. Competitive products proceed through the ANDA pathway as generics, not through the biosimilar pathway under the Biologics Price Competition and Innovation Act.

The relevant market-access issues are therefore:

• Paragraph III or Paragraph IV certifications;
• bioequivalence to Oxtellar XR;
• FDA approval of the extended-release dosage form;
• patent litigation and stays; and
• state substitution and commercial contracting.

What licensing deals affect Patent 8,821,930?

The commercial record identifies Supernus Pharmaceuticals as the principal holder and commercializer associated with Oxtellar XR. No material third-party license is established by the claim text alone. Patent ownership, assignment history, and any security interests should be reviewed through USPTO assignment records and SEC filings before a transaction or freedom-to-operate opinion.[5][6]

A license covering the ’930 patent would need to address:

• U.S. and foreign family members;
• continuation patents;
• authorized generic rights;
• formulation improvements;
• sublicense rights;
• settlement restrictions; and
• launch timing after patent expiry.

How does Patent 8,821,930 compare with competing oxcarbazepine patent strategies?

The ’930 patent is formulation-focused. It does not compete directly with patents claiming:

• oxcarbazepine chemical forms;
• active-metabolite treatment methods;
• manufacturing processes;
• particle-size control;
• crystalline forms;
• dosing regimens without formulation limitations; or
• packaging and stability systems.

Its commercial value is concentrated in once-daily extended-release products. Immediate-release Trileptal formulations and conventional oxcarbazepine tablets do not necessarily practice the claimed combination.

The patent is geographically limited to the United States. Foreign counterparts must be analyzed separately because claim scope, prosecution history, validity standards, patent-term rules, and regulatory linkage differ across Europe, Canada, Japan, and other markets.

Key Takeaways

• U.S. Patent 8,821,930 covers once-daily oxcarbazepine formulations using a homogeneous matrix, a solubility-enhancing agent, and a pH-dependent release-promoting polymer.
• The listed polymer and excipient classes are broad, but the combination and percentage ranges narrow the claim.
• Claims 17, 19, and 20 directly target 600-mg oxcarbazepine tablets.
• Claims 14 through 16 add MHD blood-level and fluctuation limitations that may be difficult to prove in litigation.
• The patent is associated with Oxtellar XR and has a reported Orange Book expiration date of November 7, 2027.
• Generic competition is governed by ANDA and Paragraph IV procedures, not biosimilar regulation.
• The principal design-around strategies involve changing the matrix architecture, pH-dependent polymer, release mechanism, percentage ranges, or tablet strength.
• A complete freedom-to-operate analysis must include continuation patents, foreign counterparts, Orange Book listings, ANDA certifications, and litigation outcomes.

FAQs

Does Patent 8,821,930 cover oxcarbazepine as an active ingredient?

No. It covers a specified pharmaceutical formulation containing oxcarbazepine. The claims do not broadly monopolize oxcarbazepine, immediate-release products, or every extended-release formulation.

Does a 600-mg oxcarbazepine tablet automatically infringe the patent?

No. The tablet must also satisfy the claimed matrix, solubility-enhancing, and pH-dependent release-promoting polymer limitations. Claims 17, 19, and 20 become relevant only when those additional elements are present.

Can a generic avoid the patent by using a capsule instead of a tablet?

Potentially. Claim 18 expressly includes capsules, so changing the dosage form alone may not avoid claim 1 or claim 18. A capsule would need to avoid a substantive formulation limitation.

Is Eudragit L100-55 specifically named in the patent claims?

Yes. Claim 1 expressly identifies Eudragit L100-55, described as methacrylic acid-ethyl acrylate copolymer in a 1:1 ratio, as a qualifying pH-dependent release-promoting polymer.

Does the patent protect a sigmoidal dissolution profile?

Yes. Claim 9 covers a formulation that releases oxcarbazepine in vitro over time at a sigmoidal rate. The practical enforceability of that claim depends on the test method and the measured release curve.

References

1. United States Patent and Trademark Office. (2014). U.S. Patent No. 8,821,930, Pharmaceutical compositions containing oxcarbazepine.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. United States District Court for the District of Delaware. (2017). Supernus Pharmaceuticals, Inc. v. TWi Pharmaceuticals, Inc., patent-infringement proceedings concerning oxcarbazepine extended-release formulations.
4. Food, Drug, and Cosmetic Act, 21 U.S.C. § 355(j).
5. United States Patent and Trademark Office. (n.d.). Patent Center and assignment database.
6. Supernus Pharmaceuticals, Inc. (n.d.). Form 10-K annual reports and Oxtellar XR intellectual-property disclosures.

Drugs Protected by US Patent 8,821,930

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			Y
Supernus Pharms	OXTELLAR XR	oxcarbazepine	TABLET, EXTENDED RELEASE;ORAL	202810-002	Oct 19, 2012	AB	RX	Yes	No			Y
Supernus Pharms	OXTELLAR XR	oxcarbazepine	TABLET, EXTENDED RELEASE;ORAL	202810-003	Oct 19, 2012	AB	RX	Yes	Yes			Y

International Family Members for US Patent 8,821,930

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
European Patent Office	2359830