US Patent 8,409,616: Claim Scope, Abuse-Deterrent Formulations, Expiration and Patent Landscape

US Patent 8,409,616 covers pharmaceutical compositions that combine an abuse-susceptible, water-soluble drug with a gel-forming polymer, a disintegrant, and a surfactant or sorbitan monoester. The broadest claim requires the ingredients to be present as a mixture. Dependent claims narrow the invention through polyethylene oxide, specific molecular-weight ranges, defined excipients, weight percentages, unit-dose formats, and dosage-form limitations.

The patent is composition-focused. It does not claim a particular active drug, therapeutic indication, manufacturing process, patient population, or method of treating a named disease. Its commercial relevance depends on whether a marketed or proposed product contains the claimed excipient combination within the stated ranges.

What does US Patent 8,409,616 claim?

The patent has two independent composition claims.

Claim	Core subject matter	Key limitations
1	Abuse-susceptible drug composition	Water-soluble drug, gel-forming polymer, disintegrant, and sorbitan monoester
10	Abuse-susceptible drug composition	Water-soluble drug, gel-forming polymer, disintegrant, and surfactant; immediate-release profile

Claim 1 requires:

A water-soluble drug susceptible to abuse at about 0.5% to about 25% by weight.
A gel-forming polymer at about 3% to about 40% by weight.
A disintegrant at about 2% to about 25% by weight.
A sorbitan monoester at about 1% to about 10% by weight.

The disintegrant must be one of three listed materials:

Crospovidone.
Sodium starch glycolate.
Croscarmellose sodium.

Claim 10 is structurally broader in some respects because it requires a surfactant rather than specifically a sorbitan monoester. It also requires that the disintegrant be present in an amount sufficient to produce an immediate-release profile.

The use of “comprising” makes both independent claims open-ended. A formulation can contain additional excipients and remain within the claims if it satisfies every stated limitation.

How broad is the scope of claim 1?

Claim 1 is broad across the active pharmaceutical ingredient category. It does not identify oxycodone, hydrocodone, morphine, tramadol, codeine, or another named compound. A formulation may therefore fall within the claim based on the drug’s properties rather than its chemical name.

The drug must satisfy two functional and compositional requirements:

It must be water soluble.
It must be susceptible to abuse.

The claim does not provide a numerical solubility threshold or an exhaustive definition of abuse susceptibility. That creates a fact-intensive infringement question. A party evaluating risk would likely examine:

A drug’s aqueous solubility at relevant pH values.
Whether the drug has recognized abuse potential.
Whether the product is administered orally, intranasally, or parenterally.
Regulatory classification under the Controlled Substances Act.
Product labeling and abuse-deterrence materials.
Expert evidence concerning whether the drug fits the claim language.

The claim is narrower than a claim to any abuse-deterrent formulation because all four required ingredient categories must be present.

What excipients and dosage forms are protected?

Gel-forming polymer

Claim 2 limits the gel-forming polymer to polyethylene oxide. Claim 3 narrows that limitation to polyethylene oxide having an average molecular weight from 300,000 to approximately 5,000,000.

This range covers grades commonly used to create high-viscosity matrices. The molecular weight is commercially significant because polyethylene oxide grades can differ materially in:

Hydration rate.
Viscosity.
Swelling behavior.
Resistance to mechanical disruption.
Drug-release characteristics.
Processing performance.

A formulation using a different gel-forming polymer may remain within claim 1 or claim 10 if the polymer satisfies the broader claim language. It would not satisfy claim 2 unless it uses polyethylene oxide.

Disintegrants

The claims identify three permitted disintegrants:

Disintegrant	Claim relevance
Crospovidone	Expressly listed
Sodium starch glycolate	Expressly listed
Croscarmellose sodium	Expressly listed

Claim 5 specifically requires croscarmellose sodium. Claims 10 and 17 also use the listed-disintegrant framework.

The disintegrant is central to the claimed technical balance. The gel-forming polymer can increase viscosity and retard manipulation, while the disintegrant promotes dosage-form breakup and, in claim 10, an immediate-release profile. The claims therefore cover a formulation strategy that combines abuse-deterrence-related gelling with rapid dosage-form disintegration.

Sorbitan monoester and surfactant

Claim 1 requires a sorbitan monoester. Claim 4 narrows the amount to approximately 1% to 3% by weight.

Examples of sorbitan monoesters commonly used in pharmaceutical formulations include:

Sorbitan monolaurate.
Sorbitan monoleate.
Sorbitan monostearate.
Sorbitan monopalmitate.

The claim text supplied does not limit the monoester to one specific chemical species. A formulation assessment would need to determine whether the selected excipient is chemically a sorbitan monoester rather than another surfactant class.

Claim 10 is broader because it recites “a surfactant.” A product could potentially avoid claim 1 by omitting a sorbitan monoester while still raising claim 10 issues if it contains another surfactant, the required gel-forming polymer, an eligible disintegrant, and the required immediate-release behavior.

Additional excipients and dosage forms

Claims 6 and 7 expressly permit:

Microcrystalline cellulose.
Polyethylene glycol.

Claims 8 and 11 require unit-dose form. Claims 9 and 12 identify the following dosage forms:

Suppository.
Capsule.
Caplet.
Pill.
Gel.
Soft gelatin capsule.
Compressed tablet.

These claims do not require a tablet. The patent therefore reaches multiple oral and nonoral dosage-form architectures, although practical infringement analysis would depend on whether the formulation satisfies the independent claim from which each dependent claim depends.

What is the difference between claims 1 and 10?

The two independent claims create separate infringement pathways.

Issue	Claim 1	Claim 10
Drug amount	0.5% to 25%	Not required in independent claim
Gel-forming polymer	3% to 40%	3% to 40%
Disintegrant amount	2% to 25%	Not required in independent claim
Disintegrant identity	Three listed materials	Not specified in independent claim
Surfactant	Sorbitan monoester	Any qualifying surfactant
Surfactant amount	1% to 10%	Not required in independent claim
Release requirement	None stated	Immediate-release profile
Open-ended formulation	Yes	Yes

Claim 1 is more specific about ingredient identity and concentration. Claim 10 is less specific on those points but adds the functional requirement of immediate release.

A formulation could therefore:

Infringe claim 1 but not claim 10 if it uses a sorbitan monoester and the specified ranges but does not exhibit immediate release.
Infringe claim 10 but not claim 1 if it uses a non-sorbitan surfactant and meets the immediate-release requirement.
Potentially infringe both claims if it satisfies both sets of limitations.

What technical problem does the patent address?

The claims target the formulation of water-soluble drugs with recognized abuse potential. The formulation architecture uses a combination of:

A hydrophilic or gel-forming polymer.
A disintegrant.
A surfactant or sorbitan monoester.
A water-soluble active drug.

Polyethylene oxide can hydrate and form a viscous gel. That behavior may affect extraction, crushing, dissolution, and manipulation. The disintegrant operates in the opposite direction by promoting breakup of the dosage form. The claimed combination is therefore not a simple extended-release matrix claim. Claim 10 expressly requires immediate release, while the polymer limitation preserves a gelling component.

The patent claims composition structure, not a specified abuse-deterrence performance threshold such as resistance to syringeability, snorting, heating, or solvent extraction. The absence of a quantitative performance limitation can broaden literal claim coverage, but it may also make claim construction and validity disputes more dependent on the specification and prosecution history.

How strong are the claims against a generic formulation?

A generic or follow-on manufacturer would typically evaluate the following design-around options:

Design-around strategy	Potential effect
Use a nonlisted disintegrant	May avoid claims requiring one of the three listed disintegrants
Omit the sorbitan monoester	May avoid claim 1, but claim 10 may remain relevant
Use a nonpolyethylene-oxide gelling agent	May avoid claims 2 and 3, but not necessarily claims 1 or 10
Keep polymer below 3% or above 40%	May avoid the express polymer range, subject to “about” construction
Keep drug concentration outside the stated range	May avoid claim 1 and dependent claim 13
Use a non-immediate-release product	May avoid claim 10
Use a dosage form outside the listed forms	May avoid claims 9 and 12, but not the independent claims
Use a non-water-soluble or non-abuse-susceptible active	May avoid the drug limitation

The strongest design-around opportunities concern ingredient identity, polymer concentration, and release profile. The “about” language complicates simple numerical avoidance. Courts generally assess whether a concentration outside a stated range is equivalent to the claimed range, based on intrinsic evidence, prosecution history, and technical facts.

What validity issues could affect US Patent 8,409,616?

Obviousness

The central obviousness question would be whether prior art already taught combining:

A water-soluble abuse-prone drug.
A gel-forming polymer, particularly polyethylene oxide.
A conventional disintegrant.
A surfactant or sorbitan monoester.
A release profile or abuse-deterrence objective.

A challenger could argue that the components were individually conventional and that combining them would have been predictable. The patent owner would likely rely on unexpected release, extraction, tampering, or abuse-deterrence results.

Written description and enablement

The broad drug category may raise written-description and enablement questions if the specification does not adequately support a broad range of water-soluble abuse-susceptible drugs. The analysis would focus on whether the patent teaches a representative scope or provides sufficient guidance to formulate the full genus without undue experimentation.

Indefiniteness

Potentially fact-sensitive terms include:

“Water soluble.”
“Susceptible to abuse.”
“About.”
“Gel-forming polymer.”
“Sufficient to cause.”
“Immediate release profile.”

Claim 10 presents the greatest functional-claim issue because “immediate release profile” is not expressed in the supplied claim text through a dissolution percentage or time point. The patent specification, prosecution record, and technical standards would be important to determine whether the term has a sufficiently objective boundary.

What is the Orange Book status of US Patent 8,409,616?

A patent number alone does not establish Orange Book listing status. The Orange Book lists patents submitted for approved drug products, including qualifying patents covering a drug substance, drug product, or method of use. The listed patent must be linked to a specific approved application and submitted by the relevant applicant or patent owner under FDA rules.[2]

US Patent 8,409,616 is drafted as a broad pharmaceutical composition patent. The supplied claims do not identify:

A specific active ingredient.
An approved product.
A New Drug Application.
A dosage strength.
A therapeutic indication.
An FDA-approved label.

Accordingly, the claim text does not establish an Orange Book listing or a Paragraph IV exposure for a particular product.

If the patent were listed against an approved product, a generic applicant could face a Paragraph IV certification if its ANDA product were alleged to infringe or if the listed patent were invalid or unenforceable. The statutory framework is governed principally by the Hatch-Waxman provisions in 21 U.S.C. § 355(j) and 35 U.S.C. § 271(e)(2).[3,4]

When does US Patent 8,409,616 lose exclusivity?

The patent issued on April 2, 2013, according to the patent record. Patent expiration is not determined by the issue date. For a modern US utility patent, the ordinary term generally runs 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and related statutory calculations.[1]

The claims supplied do not contain the filing history, priority chain, patent-term adjustment, or terminal-disclaimer information needed to state a legally reliable expiration date. A definitive exclusivity analysis must use the USPTO continuity data and the official patent-term calculation.

The patent’s commercial exclusivity also depends on whether:

The patent remains unexpired.
Any continuation or divisional patent has issued.
A terminal disclaimer applies.
The patent is listed for an FDA-approved product.
A court has invalidated or narrowed the claims.
A settlement or license limits enforcement.

Which companies are most relevant to the competitive landscape?

The claim category intersects with several commercial groups:

Branded opioid companies developing abuse-deterrent formulations.
Generic manufacturers filing ANDAs for controlled-release or immediate-release opioid products.
Specialty pharmaceutical companies licensing abuse-deterrent technologies.
Contract manufacturers with high-viscosity polymer and multiparticulate formulation capabilities.
Companies developing tamper-resistant tablets, capsules, and solid oral dosage forms.

Relevant competitive technologies may use different approaches, including:

High-molecular-weight polyethylene oxide matrices.
Sequestered antagonists.
Irritant agents.
Solidification or gelling systems.
Hard-to-crush tablets.
Multiparticulate dosage forms.
Physical barriers to injection or solvent extraction.

US Patent 8,409,616 is narrower than a platform patent covering every abuse-deterrent opioid formulation because it requires a defined combination of excipient functions. Its practical strength is higher where a product uses the same disintegrant class, polymer range, and surfactant architecture.

What patent litigation and licensing risks should be assessed?

A complete freedom-to-operate review should separate five risks:

Direct infringement of claims 1 or 10 by the finished dosage form.
Induced or contributory infringement based on manufacturing or distribution activity.
Infringement of related continuation or divisional patents.
Regulatory exposure if the patent is listed against an approved product.
Contractual restrictions arising from a license, settlement, or technology-transfer agreement.

The patent number and claim text alone do not establish a litigation history, settlement agreement, license, or current enforcement position. Those issues require review of PACER, USPTO assignment and continuity records, FDA listing records, and relevant commercial agreements.

Key Takeaways

US Patent 8,409,616 claims abuse-susceptible drug compositions containing a gel-forming polymer, disintegrant, and surfactant architecture.
Claim 1 is limited by specific ingredient categories and weight ranges.
Claim 10 is broader regarding surfactant identity but requires an immediate-release profile.
Polyethylene oxide claims cover average molecular weights from approximately 300,000 to 5,000,000.
The principal design-around strategies involve changing the disintegrant, surfactant, polymer concentration, polymer identity, or release profile.
The patent does not identify a specific active drug or approved product in the supplied claims.
Orange Book status, Paragraph IV risk, patent expiration, litigation, and licensing cannot be established from the claim text alone.
Validity risk is concentrated in obviousness, functional claim construction, written description, enablement, and the meaning of “immediate release profile.”

FAQs

Does US Patent 8,409,616 specifically cover oxycodone?

No. The supplied claims do not name oxycodone or any other active pharmaceutical ingredient. They cover a category of water-soluble drugs susceptible to abuse.

Can a formulation avoid the patent by using sodium starch glycolate instead of croscarmellose sodium?

Not necessarily. Both sodium starch glycolate and croscarmellose sodium are expressly listed in the claims. Substitution between those two ingredients would not by itself avoid the relevant Markush limitations.

Does using polyethylene oxide automatically create infringement?

No. Polyethylene oxide is only one claim element. Infringement also depends on the drug, polymer concentration, disintegrant, surfactant or sorbitan monoester, and other applicable limitations.

Is an immediate-release opioid necessarily covered by claim 10?

No. The formulation must also contain the claimed gel-forming polymer, disintegrant, surfactant, and water-soluble abuse-susceptible drug. The immediate-release characteristic alone is insufficient.

Can a manufacturer avoid claim 10 by using a controlled-release formulation?

Potentially, if the product does not exhibit the claimed immediate-release profile. Claims 1 and other dependent claims would still require separate analysis because claim 1 does not expressly require immediate release.

References

United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term examination guidance. USPTO.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA.
21 U.S.C. § 355. (2024). Applications for FDA approval to market new drugs.
35 U.S.C. § 271(e). (2024). Infringement of patents relating to regulated products.
United States Patent and Trademark Office. (2013). U.S. Patent No. 8,409,616. Washington, DC: U.S. Department of Commerce.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2004294953	⤷ Start Trial
Australia	2010200979	⤷ Start Trial
Australia	2013206525	⤷ Start Trial
Australia	2015264950	⤷ Start Trial
Australia	2017239544	⤷ Start Trial
Canada	2547334	⤷ Start Trial
European Patent Office	1694260	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,409,616

Summary for Patent: 8,409,616