Details for Patent: 7,815,934

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Which drugs does patent 7,815,934 protect, and when does it expire?

Patent 7,815,934 protects EMBEDA and TROXYCA ER and is included in two NDAs.

This patent has sixteen patent family members in twelve countries.

Summary for Patent: 7,815,934

Title:	Sequestering subunit and related compositions and methods
Abstract:	A sequestering subunit comprising an aversive agent and a blocking agent, wherein the blocking agent substantially prevents release of the aversive agent from the sequestering subunit in the gastrointestinal tract for a time period that is greater than 24 hours; a composition comprising a sequestering subunit and a therapeutic agent in releasable form, wherein, optionally, the mechanical fragility of the sequestering subunit is the same as the mechanical fragility of the therapeutic agent in releasable form; a capsule or tablet comprising a sequestering subunit and a therapeutic agent; and a method of preventing abuse of a therapeutic agent.
Inventor(s):	Garth Boehm
Assignee:	Alpharma Pharmaceuticals LLC
Application Number:	US10/667,676
Patent Claim Types: see list of patent claims	Use; Composition;

United States Patent 7,815,934: Claim Scope, Expiration, Orange Book Relevance, and Patent Landscape

U.S. Patent No. 7,815,934 protects abuse-deterrent oral opioid compositions that combine a releasable opioid agonist, particularly morphine, with sequestered naltrexone. The patent’s core technology is a coated naltrexone-containing bead or subunit in which a hydrophobic polymer and surfactant materially suppress naltrexone release in the gastrointestinal tract. The opioid agonist is applied as an outer, releasable overcoat.

The broadest enforceable commercial risk centers on compositions containing morphine and a naltrexone sequestering subunit using sodium lauryl sulfate, alone or with Eudragit RS PO. The patent does not claim every abuse-deterrent opioid formulation, every naltrexone-containing dosage form, or every opioid antagonist combination.

What Does U.S. Patent 7,815,934 Cover?

The patent covers three related claim groups:

Claim group	Claims	Principal subject matter
Combination composition claims	1-7	Naltrexone sequestering subunit plus releasable opioid agonist overcoat
Structural formulation claims	8-15	Naltrexone core on a substrate, hydrophobic/surfactant coating, and opioid overcoat
Standalone sequestering-subunit claims	16-18	Naltrexone subunit with release-blocking surfactant system

The technical concept is a multipart abuse-deterrent dosage form. The opioid agonist is available for therapeutic release, while the antagonist remains substantially unavailable in the gastrointestinal tract during normal use.

Claim 1: Broad combination claim

Claim 1 requires all of the following:

1. A pharmaceutical composition.
2. A sequestering subunit containing naltrexone or a pharmaceutically acceptable salt.
3. A blocking agent containing a surfactant.
4. The blocking agent substantially prevents naltrexone release from the subunit.
5. The sequestering subunit is overcoated with an opioid agonist or salt in releasable form.

The claim is functional in important respects. It does not require a particular bead size, manufacturing process, polymer concentration, opioid dose, or release profile beyond the requirement that the blocking agent substantially prevent naltrexone release.

A competing formulation could avoid literal infringement if it lacks a surfactant-containing blocking agent, does not use an overcoat, or does not contain naltrexone in a discrete sequestering subunit. The doctrine of equivalents could remain relevant, particularly for a chemically different release-barrier system performing substantially the same function in substantially the same way.

Claims 2 and 3: Release-performance limitations

Claims 2 and 3 add quantified gastrointestinal release limitations:

• Claim 2 requires prevention of at least approximately 99% of naltrexone release for at least approximately 12 hours.
• Claim 3 requires prevention of at least approximately 95% of release for more than 24 hours.

These claims narrow the scope but create technical infringement questions. The parties would likely dispute:

• The assay used to measure release.
• The definition of the gastrointestinal environment.
• Whether the percentage refers to total dose, available naltrexone, or cumulative release.
• The meaning of “about.”
• Whether the result must be demonstrated for every unit, an average batch, or a representative sample.
• Whether the test is conducted under intact-dosage-form conditions or after mechanical manipulation.

The release limitations are also relevant to validity. If the specification does not provide adequate guidance across the full breadth of the claimed surfactant and opioid classes, written-description and enablement issues could arise. The claims, however, contain concrete performance thresholds that may provide useful boundaries for infringement analysis.

Claims 4 and 5: Opioid agonist selection

Claim 4 limits the opioid agonist to:

• Morphine
• Hydromorphone
• Oxycodone
• Hydrocodone
• Pharmaceutically acceptable salts

Claim 5 narrows the formulation to morphine or a salt. Morphine formulations therefore face the most direct claim coverage, particularly where morphine sulfate is used.

A product using fentanyl, methadone, tapentadol, tramadol, buprenorphine, or another opioid outside the listed group would not literally satisfy claim 4. It could still implicate claim 1, which does not contain the same express opioid list, subject to the other limitations.

Claim 6: Sodium lauryl sulfate

Claim 6 specifically identifies sodium lauryl sulfate, also known as sodium lauryl sulphate or SLS, as the surfactant.

SLS is commercially significant because it is a common pharmaceutical excipient and can function in the coating as a wetting agent, pore-modifying component, or release-controlling additive. A formulation using SLS is more exposed to claims 6, 10, and 17 than one using a different surfactant.

Claim 7: Narrow morphine/SLS/Eudragit combination

Claim 7 requires:

• Naltrexone in a sequestering subunit.
• A blocking agent containing Eudragit RS PO and SLS.
• At least 99% release prevention for at least 12 hours.
• At least 95% release prevention for more than 24 hours.
• Morphine or a pharmaceutically acceptable salt.

This is the most commercially specific claim in the first claim group. It is narrower than claim 1 but potentially more difficult to design around where a product uses the same polymer-surfactant system and morphine.

What Formulations Are Protected by Claims 8 Through 15?

Claims 8 through 15 define the dosage form more structurally than claims 1 through 7.

The required architecture is:

1. A naltrexone core.
2. The core is located on a substrate.
3. The substrate is covered by a coating containing:
   • A hydrophobic material; and
   • A surfactant.
4. The coated sequestering subunit is covered by an overcoat containing an opioid agonist.

Claim 9 specifies that the substrate can be a spheroid or bead. This language is relevant to multiparticulate capsules containing numerous coated particles rather than a single monolithic tablet.

Structural elements and design-around implications

Element	Scope implication
Naltrexone core	Requires naltrexone or an acceptable salt in the inner active region
Substrate	Requires the naltrexone to be carried on a substrate rather than merely blended into a matrix
Hydrophobic coating	Requires a hydrophobic material in the barrier coating
Surfactant	Requires a surfactant in the coating
Overcoat	Requires the opioid agonist to cover the sequestering subunit
Releasable opioid	The agonist must be available for therapeutic release
Spheroid or bead	Narrows the substrate form and supports multiparticulate products

A matrix tablet in which morphine and naltrexone are distributed throughout the same polymer matrix may avoid claims 8 through 15 if it lacks the claimed core-coating-overcoat structure. It could still implicate broader claims if it contains a discrete naltrexone subunit and a surfactant-based blocking agent.

How Do Claims 16 Through 18 Change the Patent’s Reach?

Claims 16 through 18 are important because they claim the naltrexone sequestering subunit independently of the opioid overcoat.

Claim 16 requires a subunit containing:

• Naltrexone or a salt; and
• A surfactant-containing blocking agent;
• With the specified 12-hour and 24-hour release-prevention performance.

Claims 17 and 18 narrow the surfactant to SLS and the combination of SLS with Eudragit RS PO.

These claims may reach intermediate products, drug particles, coated beads, or contract-manufactured subunits before they are combined with an opioid agonist. They also create a potential supply-chain issue. A manufacturer could face infringement exposure even if it does not sell the final opioid product, depending on the precise product, use, and applicable indirect-infringement theory.

What Is the Core Claim Construction Issue?

The principal claim construction issue is the meaning of “sequestering subunit” and “blocking agent.”

A likely construction treats the sequestering subunit as a discrete component that contains naltrexone and is engineered to prevent its release. The claim language does not necessarily require complete physical isolation from the opioid agonist, but claims 1 and 8 require an overcoat or covering relationship.

The blocking agent is not merely any excipient present in the dosage form. It must include a surfactant and must perform the claimed release-blocking function. A surfactant used solely in an external coating or in the opioid layer may not satisfy the claim unless it is part of the naltrexone release-blocking system.

The terms “substantially prevents,” “about 99%,” and “about 95%” are central to infringement and validity. The specification, prosecution history, and laboratory test conditions would be material to determining the boundaries of those terms.

What Drug Is Most Closely Associated With U.S. Patent 7,815,934?

The patent is closely associated with Embeda, an extended-release morphine sulfate and naltrexone hydrochloride product. Embeda uses morphine sulfate for analgesia and sequestered naltrexone intended to remain unavailable during normal oral administration but to interfere with opioid effects if the dosage form is manipulated and misused.[2]

Embeda product profile

Item	Information
Product	Embeda
Active ingredients	Morphine sulfate and naltrexone hydrochloride
Dosage form	Extended-release capsules containing multiparticulates
Sponsor history	King Pharmaceuticals; later associated with Pfizer
Regulatory pathway	FDA-approved new drug application
Therapeutic category	Extended-release opioid analgesic
Abuse-deterrence concept	Sequestered opioid antagonist in coated particles

The product architecture maps closely to the patent’s claims: morphine is the releasable opioid agonist, while naltrexone is placed in a coated subunit designed to restrict gastrointestinal release.

What Is the Orange Book Status of U.S. Patent 7,815,934?

U.S. Patent 7,815,934 has been associated with the Embeda product and is relevant to FDA-listed patent protection for the morphine sulfate/naltrexone hydrochloride extended-release capsule product.[3]

Orange Book listing does not determine claim validity or infringement. It provides regulatory notice of patents submitted for an approved drug. The listed patent may be challenged through an Abbreviated New Drug Application Paragraph IV certification if a generic applicant asserts that the patent is invalid, unenforceable, or not infringed.

The practical Orange Book questions are:

• Whether the patent remains listed for the relevant Embeda strengths.
• Whether the listing carries a method-of-use code or product formulation code.
• Whether the patent term has expired.
• Whether a later generic applicant has submitted a Paragraph IV certification.
• Whether pediatric exclusivity or other statutory extensions affect the effective date.

The patent’s relevance is strongest for a generic that copies the morphine/naltrexone multiparticulate architecture rather than for a generic using a materially different abuse-deterrent design.

When Does U.S. Patent 7,815,934 Lose Exclusivity?

The patent issued on October 19, 2010.[1] Its term is generally measured from the earliest effective nonprovisional filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable extension.

Public patent records associate the patent family with a September 12, 2003 priority date. On that basis, the nominal 20-year term would run to September 12, 2023, unless the effective term is governed by a later benefit claim or modified by patent-term adjustment. Patent records commonly identify a later expiration date in 2025 for this patent family, reflecting the applicable U.S. term calculation and adjustment.

The commercial analysis should therefore distinguish:

Date type	Significance
Priority date	Establishes priority for patentability and family analysis
Filing date	Affects statutory patent term
Issue date	Does not ordinarily determine expiration
Patent-term adjustment	Can extend the ordinary term
Patent-term extension	May apply for regulatory delay, subject to statutory requirements
Orange Book expiration	May reflect the FDA-listed term and exclusivity coding

A patent’s expiration date should be confirmed against the USPTO patent record and the current Orange Book entry before making a launch decision. The patent is not a biologic exclusivity right, and biosimilar exclusivity rules do not apply.

Are Biosimilars Relevant to This Patent?

No. Biosimilar risk is not relevant because the claimed subject matter is a small-molecule pharmaceutical composition containing morphine and naltrexone.

The competitive challenge would arise through an ANDA, not a 351(k) biosimilar application. A generic applicant would need to address:

• Pharmaceutical equivalence.
• Bioequivalence.
• Extended-release performance.
• Abuse-deterrent labeling and formulation requirements.
• Orange Book-listed patents.
• Paragraph IV certification and potential 30-month stay.

Which Companies Are Most Likely to Challenge the Patent?

The most likely challengers would be generic manufacturers capable of producing multiparticulate extended-release opioid products, including companies with controlled-release coating technology and opioid manufacturing infrastructure.

Potential categories include:

• Large generic manufacturers.
• Specialty controlled-substance manufacturers.
• Companies acquiring or licensing opioid-abuse-deterrent technology.
• Contract manufacturers with fluid-bed coating and multiparticulate capabilities.

A generic company using a simple morphine extended-release matrix would not necessarily practice the asserted claims. A copy using coated naltrexone beads, SLS, Eudragit RS PO, and morphine would present substantially greater Paragraph IV risk.

No conclusion about a particular company’s infringement position follows solely from the patent claims. Product composition, manufacturing records, ANDA formulation details, and the certification position would control.

What Paragraph IV Risks Exist for a Generic Embeda Product?

A generic applicant would face the following principal risk scenarios:

Generic design	Claim exposure
Morphine overcoat on naltrexone beads using SLS and Eudragit RS PO	High exposure to claims 1-18
Morphine overcoat on naltrexone beads using a different surfactant	Potential exposure to claims 1-5, 8-9, 11-15, and 16
Naltrexone in a hydrophobic matrix without a discrete overcoat	Lower exposure to structural claims; functional claims require analysis
Opioid and naltrexone in a single matrix	Potential design-around of claims requiring overcoating
Different antagonist, such as naloxone	Generally outside literal naltrexone limitations
Different opioid outside claim 4	May avoid dependent claims but not necessarily claim 1 or claim 8
No surfactant in the blocking system	Stronger design-around position
Release-blocking layer based on a non-surfactant mechanism	Potentially outside the claims if the claim limitation is absent

The strongest design-around paths are changing the antagonist, eliminating the surfactant from the naltrexone barrier, using a non-overcoat architecture, or employing a matrix formulation that does not contain the claimed discrete sequestering subunit.

What Manufacturing and Intellectual Property Barriers Does the Patent Create?

The patent creates barriers around multiparticulate processing rather than around morphine or naltrexone themselves.

Relevant manufacturing operations include:

• Loading naltrexone onto a bead or spheroid substrate.
• Applying a hydrophobic polymer coating.
• Incorporating SLS into the coating.
• Achieving reproducible release suppression.
• Applying morphine as an external overcoat.
• Encapsulating the coated particles without damaging the barrier.
• Controlling particle-size distribution and dose uniformity.

The release-performance limitations create a higher evidentiary burden than purely compositional claims. A manufacturer may need comparative dissolution testing under simulated gastrointestinal conditions to determine whether its formulation reaches the claimed 99% and 95% thresholds.

Trade-secret and know-how barriers may persist after patent expiration if the commercial product depends on proprietary coating parameters, spray rates, curing conditions, solvent systems, or particle-handling processes. Those process details are separate from the patent’s legal scope.

How Strong Is the Patent Estate for Embeda?

U.S. Patent 7,815,934 is technically significant within the Embeda formulation architecture because it contains:

• Broad functional composition claims.
• Narrow morphine claims.
• Specific SLS claims.
• SLS/Eudragit RS PO combination claims.
• Structural bead and overcoat claims.
• Standalone sequestering-subunit claims.

Its strength is greatest against a close copy of the original multiparticulate design. Its strength is weaker against:

• A single-matrix formulation.
• A non-surfactant barrier.
• A different antagonist.
• A dosage form lacking a discrete opioid overcoat.
• A formulation that fails the claimed gastrointestinal release thresholds.

Validity risk would focus on prior-art abuse-deterrent compositions, opioid-antagonist combinations, coated multiparticulates, and the adequacy of the specification for the claimed release performance. The patent’s layered claim structure improves fallback coverage, but the dependent claims are highly specific and may be easier to avoid through formulation redesign.

What Litigation and Settlement Issues Affect the Patent?

The principal legal risk would arise from an ANDA Paragraph IV challenge or from commercial activity involving a morphine/naltrexone formulation that practices the claimed subunit architecture.

Relevant litigation issues include:

1. Infringement: Whether the generic contains a surfactant-based naltrexone blocking system and an opioid overcoat.
2. Claim construction: Whether “overcoated,” “sequestering subunit,” and “substantially prevents” require the physical architecture described in the specification.
3. Validity: Whether prior art discloses the combination and whether the release limitations are adequately supported.
4. Inducement: Whether labeling directs use of a formulation that satisfies the claims.
5. Regulatory stay: Whether a timely Paragraph IV notice triggers the Hatch-Waxman 30-month stay.
6. Settlement: Whether any agreement restricts generic launch, licenses technology, or provides a specific entry date.

A patent settlement would not alter the intrinsic scope of the claims. It would affect commercial launch timing through contractual rights and regulatory commitments. A current litigation conclusion cannot be drawn from the patent document alone.

How Does U.S. Patent 7,815,934 Compare With Competing Abuse-Deterrent Opioid Patents?

Product or technology	Main deterrence approach	Relationship to Patent 7,815,934
Embeda	Morphine plus sequestered naltrexone	Closest commercial alignment
OxyContin OP	Physically resistant oxycodone tablet	Different active ingredient and architecture
Hysingla ER	Abuse-deterrent hydrocodone matrix	Generally different formulation structure
Xtampza ER	Microsphere-based oxycodone formulation	Different opioid and multiparticulate design
Arymo ER	Abuse-deterrent morphine matrix	Morphine overlap commercially, but not necessarily naltrexone subunit overlap
Targiniq ER	Oxycodone plus naloxone	Different antagonist and opioid combination

The key distinction is the antagonist. Patent 7,815,934 is directed to naltrexone sequestration, while other products use naloxone, physical tablet resistance, polymeric matrices, or microsphere technology.

Key Takeaways

• U.S. Patent 7,815,934 covers abuse-deterrent opioid compositions pairing a releasable opioid agonist with a coated, naltrexone-containing sequestering subunit.
• Morphine, SLS, Eudragit RS PO, bead substrates, and opioid overcoats create the highest direct claim exposure.
• Claims 1-7 focus on the composition and functional release performance.
• Claims 8-15 add a core, substrate, hydrophobic/surfactant coating, and opioid overcoat architecture.
• Claims 16-18 independently protect the naltrexone sequestering subunit.
• The patent is closely associated with Embeda, an extended-release morphine sulfate/naltrexone hydrochloride product.
• Biosimilar rules do not apply. Any competitive challenge would proceed through the generic-drug ANDA pathway.
• The strongest design-around strategies involve changing the antagonist, removing the surfactant from the blocking system, eliminating the overcoat architecture, or using a single-matrix formulation.
• The patent’s commercial importance depends on the current USPTO term record, Orange Book listing, any pediatric or patent-term adjustment, and the existence of Paragraph IV litigation or settlement agreements.

FAQs About U.S. Patent 7,815,934

Does U.S. Patent 7,815,934 cover morphine alone?

No. The claims require naltrexone in a sequestering subunit. Morphine without the claimed naltrexone-containing barrier would not satisfy the central combination limitations.

Does the patent cover naloxone formulations?

Generally, no. The claims recite naltrexone, not naloxone. A naloxone formulation would require a separate infringement analysis under any potentially equivalent claim theory.

Is Eudragit RS PO required in every claim?

No. Eudragit RS PO is expressly required only in claims 7, 15, and 18. The broader claims require a surfactant-containing blocking agent but do not expressly require Eudragit RS PO.

Can a tablet infringe claims directed to beads or spheroids?

Potentially. Claims 1-7 and 16-18 do not expressly require a bead or spheroid. Claims 8-15 contain more specific structural limitations, and claim 9 expressly identifies spheroids or beads as a narrower substrate form.

What is the most important technical test for infringement?

The critical test is whether the accused naltrexone subunit uses the claimed surfactant-based blocking system and achieves the specified gastrointestinal release-prevention levels, together with the required opioid-overcoat or subunit architecture.

References

1. United States Patent No. 7,815,934, Pharmaceutical compositions comprising an opioid agonist and an opioid antagonist, issued October 19, 2010, United States Patent and Trademark Office.

2. U.S. Food and Drug Administration. (2014). Embeda (morphine sulfate and naltrexone hydrochloride) extended-release capsules: Prescribing information. FDA.

3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

4. United States Code, Title 35, §§ 154 and 156.

5. U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application approvals and Paragraph IV patent certifications. FDA.

Drugs Protected by US Patent 7,815,934

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-001	Aug 13, 2009		DISCN	Yes	No	7,815,934		Y
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-002	Aug 13, 2009		DISCN	Yes	No	7,815,934		Y
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-003	Aug 13, 2009		DISCN	Yes	No	7,815,934		Y

International Family Members for US Patent 7,815,934

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2003270778
Australia	2009251081
Canada	2499550