Details for Patent: 7,682,634

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Which drugs does patent 7,682,634 protect, and when does it expire?

Patent 7,682,634 protects EMBEDA and is included in one NDA.

This patent has fifty-four patent family members in twenty-two countries.

Summary for Patent: 7,682,634

Title:	Pharmaceutical compositions
Abstract:	Provided herein is a pharmaceutical composition comprising an antagonist, an agonist, a seal coat, and a sequestering polymer, wherein the antagonist, agonist, seal coat and at least one sequestering polymer are all components of a single unit, and wherein the seal coat forms a layer physically separating the antagonist from the agonist from one another. Methods for manufacturing such a pharmaceutical composition are also provided.
Inventor(s):	Frank Matthews, Garth Boehm, Lijuan Tang, Alfred Liang
Assignee:	Alpharma Pharmaceuticals LLC
Application Number:	US12/399,923
Patent Claim Types: see list of patent claims	Composition; Formulation;

United States Patent 7,682,634: Claim Scope, Exclusivity, Litigation Risk, and Patent Landscape

United States Patent 7,682,634 protects a specific abuse-deterrent, extended-release oral opioid formulation combining morphine sulfate with sequestered naltrexone hydrochloride. Claim 1 is compositionally dense and requires a defined multilayer pellet architecture, specified excipients, quantitative sequestering performance, and a controlled dissolution protocol. Claims 2 through 4 add pharmacokinetic limitations. Claims 5 through 10 narrow the formulation further.

The patent is most relevant to morphine/naltrexone products such as Embeda. Its practical strength depends on whether an accused product uses the required pellet sequence, the specified sequestering polymer system, the sodium lauryl sulfate and talc concentrations, and the claimed naltrexone-release performance. A morphine product using a different abuse-deterrence mechanism or a different dosage-form architecture may avoid literal infringement.

What drug and formulation does US 7,682,634 protect?

The patent protects a multiparticulate oral dosage form containing:

Required element	Claim requirement
Core	Water-soluble core
Antagonist layer	Naltrexone HCl coating the core
Sequestering layer	Copolymers of acrylic and methacrylic acid esters with quaternary ammonium groups
Sequestering excipients	Sodium lauryl sulfate at 1.6% to 6.3% of the polymer weight; talc at 75% to 125% of polymer weight
Agonist layer	Morphine sulfate and hydroxypropyl cellulose
Osmotic layer	Immediately beneath the agonist layer, a sodium chloride-containing layer
Controlled-release layer	Coating the agonist layer
Layer-specific restriction	Sodium lauryl sulfate appears only in the sequestering layer
Performance requirement	At least 80% of naltrexone remains sequestered at 73 hours under the stated in vitro protocol

The formulation is designed to release morphine for therapeutic analgesia while limiting the availability of naltrexone under ordinary use and under attempted manipulation. Naltrexone is the opioid antagonist; morphine is the opioid agonist.

The patent record identifies the invention as an abuse-resistant dosage-form technology associated with Alpharma Pharmaceuticals, later connected commercially with King Pharmaceuticals and Pfizer’s Embeda product portfolio. [1]

How does claim 1 operate as a patent barrier?

Claim 1 is an independent claim requiring every listed limitation. A product that omits a required element generally has a strong noninfringement position under literal claim analysis, subject to doctrine-of-equivalents issues.

The claim has five principal restriction groups.

1. Multilayer pellet architecture

The claim requires a plurality of pellets rather than a single monolithic tablet. Each pellet must contain the layers in a prescribed order:

1. Water-soluble core
2. Naltrexone-containing layer
3. Sequestering polymer layer
4. Sodium chloride osmotic pressure-regulating layer immediately beneath the morphine layer
5. Morphine sulfate and hydroxypropyl cellulose layer
6. Controlled-release outer layer

The sequence is material. A formulation placing morphine directly on the sequestering layer, placing sodium chloride elsewhere, or using a matrix tablet instead of multilayer pellets would create substantial noninfringement arguments.

2. Naltrexone sequestering system

The sequestering layer must contain a specific class of quaternary-ammonium acrylic or methacrylic copolymers. This language is directed to ion-exchange or permeability-control polymers commonly used in modified-release pharmaceutical coatings, including polymer systems commercially associated with Eudragit-type materials.

The claim also controls the excipient ratios:

• Sodium lauryl sulfate: 1.6% to 6.3% of the specified polymer weight
• Talc: 75% to 125% of the specified polymer weight

These are relatively narrow numerical limitations. A competitor could attempt to design around the claim by changing either concentration outside the claimed range, substituting another surfactant, replacing talc, or using a different sequestering polymer.

3. Morphine layer composition

The agonist layer must contain morphine sulfate and hydroxypropyl cellulose. Claims 8 and 9 further require that the agonist be located only in that layer and that morphine sulfate be the only agonist.

This structure limits products containing another opioid agonist, a morphine salt other than morphine sulfate, or morphine distributed through multiple layers. The limitation may also affect products that use a polymer matrix in which morphine is not technically confined to a discrete agonist layer.

4. Layer-specific sodium lauryl sulfate limitation

Claim 1 requires that sodium lauryl sulfate be present only in the sequestering polymer layer. This is narrower than a formulation claim merely requiring sodium lauryl sulfate somewhere in the dosage form.

Manufacturing records, coating suspensions, excipient premixes, and finished-product composition data would be important in an infringement investigation. Trace levels in another layer could create disputes over claim construction, analytical detection limits, and the meaning of “only contained.”

5. Functional sequestering result

The formulation must sequester at least 80% of naltrexone HCl at 73 hours under a defined two-stage dissolution test:

• 500 mL of 0.1 N hydrochloric acid for one hour
• 500 mL of pH 7.5, 0.05 M phosphate buffer for 72 hours
• 37°C
• USP paddle method
• 100 rotations per minute

This is a quantitative performance limitation, not merely an intended use. A product with the same ingredients and layer arrangement could still fall outside the claim if it fails the 80% threshold under the specified test.

What do claims 2 through 4 protect?

Claims 2 through 4 depend on claim 1 and impose pharmacokinetic requirements for 6-beta-naltrexol after oral administration in the fed state.

Claim	Pharmacokinetic limitation
Claim 2	AUClast at 168 hours of 1057 pg·hour/mL, subject to the unit wording in the issued claim
Claim 3	Tmax of 57.29 hours
Claim 4	Cmax of 25 pg/mL

These claims are unusually narrow. They require proof of the underlying claim 1 formulation plus the specified human pharmacokinetic result. Small differences in study design, fed-state conditions, sampling times, assay methodology, population characteristics, or statistical treatment could affect infringement analysis.

The units in claim 2 appear typographically defective in the supplied text as “pg*wmL.” The issued patent should control the interpretation. Pharmacokinetic claims also raise legal questions about whether the numerical value is an exact limitation, an inherently met limitation, or subject to ordinary analytical variability.

Because claims 2 through 4 depend on claim 1, they do not create independent protection for a different morphine/naltrexone formulation.

What formulation is protected by claim 5?

Claim 5 requires a controlled-release layer comprising:

• A cellulose
• A polyalkylene glycol
• An anionic copolymer based on methacrylic acid and ethyl acrylate
• A plasticizer

This limitation targets the outer controlled-release coating. It does not replace claim 1’s required sequestering layer, agonist layer, sodium chloride layer, or dissolution performance.

A competitor using a cellulose-only coating, a different enteric polymer, or a different plasticizer system could avoid claim 5 while remaining potentially exposed to claim 1.

What do claims 6 through 10 add?

Claim	Added restriction
Claim 6	No bittering agent, gelling agent, irritant, or emetic
Claim 7	Antagonist is contained only in the antagonist-containing layer
Claim 8	Agonist is contained only in the agonist layer
Claim 9	Morphine sulfate is the only agonist
Claim 10	Naltrexone HCl is the only antagonist

Claims 7 through 10 reinforce the discrete-layer architecture. They reduce the scope of the claims but can improve evidentiary clarity for a product that uses only morphine sulfate and naltrexone HCl in separate layers.

Claim 6 is commercially significant. Many abuse-deterrent formulations use aversive excipients, gelling materials, irritants, or emetics. This claim excludes those features and protects a formulation relying on sequestration and controlled release without those additives.

When does US 7,682,634 lose patent exclusivity?

The patent’s ordinary term is generally measured from the earliest effective nonprovisional filing date under the Uruguay Round Agreements Act framework, subject to patent-term adjustment, patent-term extension, pediatric extension, terminal disclaimers, and other statutory adjustments. [2]

Public patent records identify a March 2005 priority history for the underlying abuse-deterrent formulation technology. On that basis, the base term would ordinarily fall in the 2025 period, subject to the official USPTO term calculation and any applicable extension. [1][3]

Exclusivity component	Relevance
Patent term	Governed by the statutory filing-date framework and USPTO term calculation
Patent-term adjustment	May extend the nominal expiration date for USPTO delays
Pediatric exclusivity	Can add six months to qualifying FDA-listed exclusivity
FDA drug exclusivity	Separate from patent term and depends on the NDA and approval history
Orange Book listing	Determines whether an ANDA applicant must address the patent through certification

A patent expiration date should not be inferred solely from the issue date. The relevant commercial date is the expiration date shown in the USPTO patent record and, for an approved drug, the FDA Orange Book listing. [3][4]

What is the Orange Book status of the Embeda-related patent estate?

Embeda is an extended-release morphine sulfate product containing naltrexone hydrochloride as an abuse-deterrent component. FDA approved Embeda under NDA 022321 in 2009. [5]

The Orange Book is the controlling public FDA source for listed patents, pediatric exclusivity, and regulatory exclusivity associated with approved drug products. [4] Patent 7,682,634 should be reviewed together with any later-issued continuation or divisional patents listed for the same NDA. A single issued patent rarely represents the full commercial estate.

The practical Orange Book questions are:

• Whether 7,682,634 remains listed for the relevant NDA
• Whether the listing has expired or been delisted
• Whether later patents cover the same product
• Whether a listed patent claims the drug substance, formulation, method of use, or device
• Whether an ANDA applicant filed a Paragraph IV certification
• Whether litigation triggered a 30-month stay under Hatch-Waxman

A product’s FDA exclusivity can therefore outlast or differ from the enforceable life of an individual patent.

Which companies could challenge the patent?

Generic applicants seeking approval for an equivalent extended-release morphine product may need to address Orange Book-listed patents through one of four certifications:

• Paragraph I: no patent information is listed
• Paragraph II: the patent has expired
• Paragraph III: the applicant will wait until expiration
• Paragraph IV: the patent is invalid, unenforceable, or will not be infringed

A Paragraph IV certification can lead to Hatch-Waxman litigation and, if filed within the statutory period, a potential 30-month FDA approval stay. [6]

The main potential challengers are generic manufacturers pursuing extended-release morphine products, including large ANDA sponsors and specialty opioid manufacturers. A competitor would likely focus on:

1. Noninfringement based on a different dosage-form architecture
2. Failure to meet the 80% sequestering test
3. Different polymer, surfactant, or talc ratios
4. Lack of the claimed pharmacokinetic profile
5. Invalidity based on anticipation or obviousness
6. Indefiniteness of the functional and pharmacokinetic limitations
7. Written-description or enablement issues involving the full numerical ranges

The claims’ narrow architecture makes design-around development commercially plausible, but the same narrowness can limit invalidity attacks if the prior art does not disclose the complete layer sequence and performance result.

How strong is the patent estate?

Strengths

The strongest features are the cumulative limitations:

• Specific pellet-based multilayer structure
• Separate antagonist and agonist layers
• Defined polymer and excipient ratios
• Sodium chloride positioned immediately beneath the agonist layer
• Sodium lauryl sulfate confined to one layer
• Quantified 73-hour sequestering result
• Human pharmacokinetic claims in dependent claims

A competitor may need to change several formulation variables at once to avoid claim 1.

Weaknesses

The estate has several potential vulnerabilities:

• Narrow numerical ranges may permit practical design-arounds
• Functional sequestering performance can create testing and reproducibility disputes
• Pharmacokinetic claims may be difficult to prove because of biological variability
• The priority and term history may place the patent near or beyond its ordinary expiration period
• Patent 7,682,634 alone does not establish protection for every morphine/naltrexone dosage form
• Later continuation patents may carry the more commercially relevant surviving claims

The patent is strongest against a product that deliberately copies the Embeda-type pellet design. It is weaker against a matrix tablet, a different multiparticulate system, a non-naltrexone abuse-deterrent formulation, or a formulation using a different antagonist-sequestering mechanism.

How does this patent compare with competing abuse-deterrent opioid patents?

Product or technology	Primary opioid	Abuse-deterrent approach	Relationship to US 7,682,634
Embeda	Morphine sulfate	Sequestered naltrexone in multilayer pellets	Directly aligned
OxyContin OP	Oxycodone HCl	Hard, non-malleable controlled-release tablet	Different active and dosage form
Hysingla ER	Hydrocodone bitartrate	Physical and chemical abuse-deterrence properties	Different active and architecture
Xtampza ER	Oxycodone	Microsphere-in-capsule formulation with abuse-deterrent properties	Different active and formulation
Generic extended-release morphine	Morphine or morphine sulfate	Product-specific	Potential ANDA and design-around risk

FDA’s abuse-deterrent labeling guidance and product-specific approvals should be evaluated separately from patent scope. Regulatory recognition of abuse-deterrent properties does not itself establish patent infringement. [7]

What manufacturing and geographic barriers exist?

The patent is directed to a manufacturing process involving sequential coating and layering of multiparticulate cores. Commercial implementation may require:

• Uniform naltrexone deposition
• Controlled polymer-layer thickness
• Tight sodium lauryl sulfate and talc ratios
• Correct placement of the sodium chloride layer
• Reproducible morphine loading
• Consistent controlled-release coating
• Batch-level dissolution testing

Those process controls can create a manufacturing barrier even where patent protection is weak. They do not, however, substitute for a separate process patent.

The patent is a United States right. Equivalent foreign patents must be analyzed independently by jurisdiction. European, Canadian, Australian, and other national rights may have different claim sets, prosecution histories, term adjustments, oppositions, and expiration dates. A U.S. noninfringement position does not resolve foreign exposure.

What litigation and settlement issues affect generic entry?

The relevant litigation questions are:

• Whether an ANDA applicant filed a Paragraph IV certification
• Whether the NDA holder sued within 45 days
• Whether a 30-month stay was triggered
• Whether the case ended in judgment, dismissal, licensing, or settlement
• Whether the settlement restricted the generic launch date
• Whether the settlement included authorized-generic or supply provisions
• Whether later patents generated separate litigation

A settlement involving one Orange Book patent does not automatically resolve other listed patents or unlisted patent rights. Likewise, expiration of 7,682,634 does not guarantee immediate generic entry if a continuation patent, regulatory exclusivity period, product-specific exclusivity, or separate formulation patent remains operative.

Key Takeaways

• US 7,682,634 is a narrow formulation patent centered on multilayer morphine/naltrexone pellets.
• Claim 1 requires the complete pellet sequence, specific polymer chemistry, sodium lauryl sulfate and talc ranges, sodium chloride placement, and an 80% naltrexone-sequestration result.
• Claims 2 through 4 add highly specific 6-beta-naltrexol pharmacokinetic limitations.
• Claims 5 through 10 narrow the controlled-release coating, excipient profile, and exclusive placement of morphine and naltrexone.
• The patent is most relevant to Embeda and closely copied morphine/naltrexone formulations.
• Matrix tablets, alternative antagonist systems, different polymers, and altered excipient ratios present potential design-around routes.
• The ordinary patent term appears to fall in the 2025 period, subject to the official USPTO calculation and any FDA pediatric or regulatory exclusivity.
• Generic entry requires review of the complete Orange Book-listed patent estate, not this patent alone.
• The commercial risk is formulation-specific and depends heavily on later continuation patents, Orange Book status, ANDA certifications, and litigation history.

FAQs

Does US 7,682,634 cover all extended-release morphine products?

No. It requires naltrexone HCl, a defined multilayer pellet structure, specified coating materials, excipient ratios, and a quantitative sequestration result.

Can a product infringe if it uses a different opioid antagonist?

Literal infringement of these claims would be difficult because the claims expressly require naltrexone HCl. Doctrine-of-equivalents issues would depend on the specific substitution and prosecution history.

Does a product avoid claim 1 by using a tablet instead of pellets?

A tablet with no plurality of multilayer pellets has a strong literal noninfringement position against the pellet limitation. Other patents could still cover the tablet.

Are the 6-beta-naltrexol claims likely to cover ordinary generic morphine products?

Only if the product also satisfies every limitation of claim 1 and produces the claimed pharmacokinetic result under the specified fed-state conditions.

Does patent expiration automatically permit FDA approval of a generic?

No. FDA approval also depends on ANDA requirements, Orange Book certifications, regulatory exclusivity, any remaining listed patents, litigation stays, and product-specific approval conditions.

References

1. United States Patent and Trademark Office. (2010). U.S. Patent No. 7,682,634, abuse-resistant dosage forms and methods of use thereof.
2. 35 U.S.C. §§ 154, 156, 271(e), 282.
3. United States Patent and Trademark Office. (n.d.). Patent term adjustment.
4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
5. U.S. Food and Drug Administration. (2009). Embeda prescribing information, NDA 022321.
6. U.S. Food and Drug Administration. (n.d.). Hatch-Waxman amendments and abbreviated new drug applications.
7. U.S. Food and Drug Administration. (2015). Guidance for industry: Abuse-deterrent opioids: Evaluation and labeling.

Drugs Protected by US Patent 7,682,634

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			Y
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-002	Aug 13, 2009		DISCN	Yes	No			Y
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-003	Aug 13, 2009		DISCN	Yes	No			Y
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-004	Aug 13, 2009		DISCN	Yes	No			Y
Alpharma Pharms	EMBEDA	morphine sulfate; naltrexone hydrochloride	CAPSULE, EXTENDED RELEASE;ORAL	022321-005	Aug 13, 2009		DISCN	Yes	No			Y

International Family Members for US Patent 7,682,634

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	E552829
Australia	2007261451
Australia	2013257508
Australia	2016238844
Australia	2018201915