Details for Patent: 8,747,902

Which drugs does patent 8,747,902 protect, and when does it expire?

Patent 8,747,902 protects DYANAVEL XR, DYANAVEL XR 10, DYANAVEL XR 15, DYANAVEL XR 20, and DYANAVEL XR 5, and is included in two NDAs.

This patent has twenty-one patent family members in fourteen countries.

Summary for Patent: 8,747,902

Title:	Modified release formulations containing drug-ion exchange resin complexes
Abstract:	An aqueous liquid suspension containing a coated drug-ion exchange resin complex comprising a core composed of an amphetamine complexed with a pharmaceutically acceptable ion-exchange resin and an uncoated amphetamine-ion exchange resin complex is provided. The coated amphetamine-ion exchange resin complex is in admixture with a polymer to form a matrix. Methods of making the coated complex and the liquid suspension are described.
Inventor(s):	Ketan Mehta, Yu-Hsing Tu
Assignee:	Tris Pharma Inc
Application Number:	US14/065,842
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,747,902
Patent Claim Types: see list of patent claims	Composition; Compound; Dosage form;

United States Drug Patent 8,747,902: Claim Scope, Dyanavel XR Coverage, Patent Expiration and Generic Risk

US Patent No. 8,747,902 protects amphetamine and dextroamphetamine dosage forms that combine approximately 12-hour, barrier-coated drug-resin particles with an additional immediate-release or uncoated amphetamine component. The patent covers both solid dosage forms, including tablets and capsules, and aqueous suspensions.

The patent is directed to a multipart release architecture rather than to amphetamine as a molecule. Its principal commercial relevance is the extended-release amphetamine technology used in products associated with Tris Pharma, particularly Dyanavel XR and related amphetamine formulations. The core infringement risk is highest for a product containing all of the following: amphetamine or dextroamphetamine bound to a strong cation-exchange resin; a polymer-containing matrix; a nonionic, water-insoluble diffusion coating; an approximately 12-hour release profile; and a separate uncoated or uncomplexed amphetamine fraction.

What does US Patent 8,747,902 protect?

US 8,747,902 contains two independent composition claims.

Claim	Covered dosage form	Core subject matter
Claim 1	Orally ingestible solid or other composition	Barrier-coated amphetamine or dextroamphetamine resin particles plus an additional uncoated or uncomplexed amphetamine component
Claim 19	Aqueous oral suspension	The same multipart release system dispersed in a pharmaceutically acceptable aqueous suspension base

Claim 1 is the principal solid-composition claim. Claim 19 is the liquid-suspension counterpart. Claims 2-18 narrow claim 1, while claims 20-30 narrow claim 19.

The patent does not broadly cover every extended-release amphetamine product. It requires a specific formulation combination:

1. A drug-cation exchange resin complex.
2. A matrix containing a water-insoluble polymer, copolymer or hydrophilic polymer.
3. A nonionic, water-insoluble, water-permeable diffusion coating.
4. A coating elongation factor of approximately 125% to 400%.
5. Approximately 12-hour drug release.
6. At least one additional amphetamine-containing component that is uncoated, uncomplexed or both.

The claims therefore target a formulation that combines controlled release with an immediate-release or less-protected amphetamine fraction.

How do independent claims 1 and 19 work?

Claim 1: solid and orally ingestible compositions

Claim 1 requires barrier-coated particulates containing amphetamine or dextroamphetamine. The drug must be bound to a pharmaceutically acceptable, water-insoluble cation-exchange resin. The resin complex must also contain a polymeric matrix component.

The particle must pass through a number 40 mesh screen. In common pharmaceutical screening terminology, this corresponds to particles below approximately 425 micrometers, although the precise measurement depends on the applicable mesh standard and testing method.

The barrier coating must be:

• Water permeable.
• Water insoluble.
• Nonionic.
• Polymeric.
• High tensile strength.
• Capable of producing approximately 12-hour release.
• Characterized by an elongation factor of approximately 125% to 400%.

The composition must also contain at least one additional component from four categories:

• Uncoated dextroamphetamine-resin complex.
• Uncoated amphetamine-resin complex.
• Uncomplexed amphetamine or its salt.
• Uncomplexed dextroamphetamine or its salt.

This additional component is a central limitation. A formulation containing only coated amphetamine-resin particles would not literally satisfy claim 1 unless another claim limitation is met through an equivalent structure.

Claim 19: aqueous liquid suspensions

Claim 19 adds a pharmaceutically acceptable aqueous suspension base. The coated particles and the additional amphetamine component must be suspended in that base.

This claim is particularly relevant to extended-release oral suspensions such as Dyanavel XR. A competing liquid product may face literal claim exposure if it uses the same resin-complex and coating architecture, even if the suspension vehicle, flavor system, preservative package or concentration differs.

The claim does not require a specific aqueous excipient. A design using a different sweetener, buffer, suspending agent or viscosity modifier may remain within the claim if the active particles and release architecture satisfy the independent limitations.

What formulations are protected by the dependent claims?

Claims	Limitation added	Commercial significance
2-4	Solid dose form, tablet, capsule or orally dissolving tablet	Extends the formulation concept beyond liquid suspension products
5-7	Water-insoluble polymer, including acrylate polymer or ethyl acrylate/methyl methacrylate copolymer	Points toward specific diffusion-coating systems such as acrylic copolymers
8	Uncoated dextroamphetamine-resin complex	Narrows the immediate-release or fast-release fraction
9	Uncomplexed amphetamine or dextroamphetamine	Covers free drug or pharmaceutically acceptable salt outside the resin complex
10	Both uncoated dextroamphetamine-resin complex and uncomplexed amphetamine or dextroamphetamine	Creates a more specific multipart release profile
11-12	Plasticizer at approximately 2%-20%, or 5%-20%, of the coating	Captures coating formulations using plasticized polymers
13	Coating at approximately 35%-50% by weight of the drug-resin-polymer particulate	Adds a substantial coating-load limitation
14	Matrix polymer at approximately 5%-20% by weight of the resin complex	Limits internal matrix composition
15-16	Strongly acidic resin, including sulfonated styrene-divinylbenzene copolymer	Narrows the ion-exchange resin chemistry
17-18	Hydrophilic polymer, including polyvinylpyrrolidone	Protects an alternative matrix architecture
20-30	Corresponding limitations for aqueous suspensions	Extends the narrower limitations to liquid products

The dependent claims create multiple infringement pathways. A product may avoid a specific dependent claim, such as claim 7, by using a non-acrylate coating, while still potentially implicating claim 1 or claim 19.

What is the technical scope of the resin and coating limitations?

Ion-exchange resin complex

The drug must be bound to a water-insoluble cation-exchange resin. Claims 15, 16 and 29 identify strongly acidic resins, including sulfonated styrene-divinylbenzene copolymers.

This requirement distinguishes the claimed technology from:

• Conventional polymer-coated drug crystals.
• Wax-matrix amphetamine tablets.
• Osmotic-release tablets.
• Multiparticulates in which amphetamine is physically dispersed but not ionically bound.
• Lipid or hydrophobic matrix systems without an ion-exchange resin.

The resin complex can control drug release by limiting drug dissolution and ion exchange in gastrointestinal fluids. The polymer matrix and external coating add further control.

Polymer matrix

The matrix may contain:

• A water-insoluble polymer.
• A water-insoluble copolymer.
• A hydrophilic polymer.
• Polyvinylpyrrolidone under claim 18.
• An acrylic copolymer under claim 7.

The matrix limitation creates a potential design-around route. A competing product that uses a resin complex without the claimed matrix polymer may challenge literal infringement, although the coating and resin structure could still raise doctrine-of-equivalents issues.

Diffusion coating

The coating is not merely any sustained-release film. It must be water permeable, water insoluble, nonionic and sufficiently elastic. The elongation factor range of approximately 125%-400% is a measurable limitation, but its application may require testing of the coating film rather than the finished multiparticulate.

Potential claim-construction disputes include:

• Whether “about 12-hour release profile” is defined by a specific dissolution method.
• Whether elongation is measured before or after application to the particle.
• Whether the coating must itself contain the nonionic polymer or may contain a blend.
• Whether “water permeable” excludes coatings that become porous or erode over time.
• Whether the coating percentage is calculated against the resin complex alone or the complete coated particle.

The patent's strongest practical limitations are the combination of drug-resin binding, polymer matrix, coating properties and mixed-release composition. Each limitation separately may be found in older pharmaceutical technology. The infringement case depends on their combination in one product.

When does US Patent 8,747,902 lose exclusivity?

US 8,747,902 issued June 10, 2014. Its patent term is generally governed by the earliest effective nonprovisional priority date and the 20-year term under the Uruguay Round Agreements Act.

Public patent records identify the patent as part of an amphetamine extended-release formulation family associated with Tris Pharma. The expected base patent-term endpoint is in December 2029, subject to any applicable patent-term adjustment, terminal disclaimer or other USPTO term determination.[1]

Event	Date or status
Patent issued	June 10, 2014
Technology	Extended-release amphetamine and dextroamphetamine resin compositions
Patent term basis	20 years from applicable earliest nonprovisional filing date
Expected base expiration	December 2029
Pediatric exclusivity	Product-specific FDA determination; not inherent in the patent
Patent-term extension	Must be checked against the approved product and regulatory record

The patent does not create regulatory exclusivity by itself. FDA exclusivity and patent protection are separate. A generic applicant may file an ANDA after the applicable statutory filing date and may challenge the patent through Paragraph IV certification.

What is the Orange Book status of US 8,747,902?

The relevant Orange Book question is product-specific. A patent may be listed against one amphetamine product and not another, even if both contain amphetamine salts and use extended-release technology.

For Dyanavel XR, the relevant FDA product is an extended-release oral suspension containing mixed amphetamine salts. The Orange Book listing analysis should be conducted against the product's NDA patent entries, expiration dates and use codes.[2]

The patent's claim language is composition-focused. It does not depend on a disease indication or dosing method. That makes it more suitable for an Orange Book composition listing than a method-of-use patent, provided the patent claims correspond to the approved formulation.

A listed composition patent can create a Paragraph IV litigation trigger. A generic applicant that certifies that the patent is invalid, unenforceable or not infringed may prompt an action under the Hatch-Waxman framework. A timely patent suit can delay FDA approval for up to 30 months, subject to statutory exceptions and court action.[3]

Which products and companies are most exposed?

Dyanavel XR

Dyanavel XR is the most direct commercial product associated with the claimed architecture because it is an extended-release amphetamine oral suspension. Tris Pharma developed the formulation platform and commercialized Dyanavel XR through its product portfolio.

A competing suspension is most exposed when it includes:

• Mixed amphetamine salts or dextroamphetamine.
• Resin-bound active pharmaceutical ingredient.
• Coated multiparticulates.
• A 12-hour release specification.
• A separate immediate-release amphetamine fraction.

Adzenys XR-ODT

Adzenys XR-ODT is an orally disintegrating extended-release amphetamine tablet. Claims 3 and 4 expressly cover tablets and orally dissolving tablets, but coverage depends on whether the product uses the claimed resin-complex and coating system.

The presence of an orally dissolving dosage form alone does not establish infringement. The product must also satisfy the technical limitations in claim 1.

Adderall XR and generic mixed amphetamine salts

Adderall XR and its generic equivalents use extended-release mixed amphetamine salts but are associated with a different bead-based technology and patent history. A product can have an extended-release profile without using a cation-exchange resin.

The patent is therefore not a general blocking patent against all generic Adderall XR products. Its relevance depends on the formulation's use of the claimed resin and polymer system.

Mydayis

Mydayis is a longer-duration mixed amphetamine salts product. Its multiparticulate design and release duration differ from the approximately 12-hour architecture emphasized in US 8,747,902. The patent may be relevant only if the product satisfies the specific resin-complex and coating limitations.

Vyvanse

Vyvanse contains lisdexamfetamine, a prodrug of dextroamphetamine. It is chemically and technically distinct from a formulation in which dextroamphetamine is bound to an ion-exchange resin. US 8,747,902 is not a direct patent on lisdexamfetamine or its prodrug mechanism.

How strong is the patent estate for the covered amphetamine products?

The estate is strongest where several related patents cover separate layers of the same product:

1. Core resin-complex composition.
2. Coated multiparticulate structure.
3. Aqueous suspension.
4. Orally disintegrating tablet.
5. Release profile.
6. Manufacturing process.
7. Product-specific FDA listing.

US 8,747,902 is valuable because it has two broad independent formulation claims covering both solids and liquid suspensions. It also contains narrower claims directed to acrylic coatings, plasticizers, strongly acidic resins and polyvinylpyrrolidone.

Its weaknesses arise from the number of technical limitations. A generic manufacturer may avoid literal infringement by changing one material or process parameter, such as:

• Using a non-resin drug matrix.
• Using a water-soluble or ionic coating.
• Eliminating the polymer matrix.
• Providing a release duration materially different from approximately 12 hours.
• Using only controlled-release particles without an uncoated or uncomplexed fraction.
• Employing free drug in a separate layer rather than within the claimed particulate composition.

The strongest invalidity arguments would likely focus on obviousness, anticipation of individual formulation elements, indefiniteness of functional release language, and written-description support for the full combination of ranges and materials.[4]

What Paragraph IV challenges and litigation risks exist?

An ANDA applicant seeking approval of a generic version of a product covered by a listed patent may use a Paragraph IV certification. The applicant must state that the patent is invalid, unenforceable or will not be infringed.

For this patent, a Paragraph IV defense would likely focus on one or more of the following:

Issue	Potential defense
Resin binding	The generic uses a non-ion-exchange formulation or a different drug-resin relationship
Matrix	The product lacks the required water-insoluble or hydrophilic polymer matrix
Coating	The coating is ionic, water soluble, erodible or outside the elongation range
Release profile	Dissolution does not provide approximately 12-hour release
Additional component	No uncoated resin complex or uncomplexed amphetamine is present
Particle size	Particles do not pass through a number 40 mesh screen
Product form	The formulation is not an aqueous suspension or does not contain the claimed solid form

A patent holder's litigation position would depend on the ANDA's detailed formulation and Paragraph IV notice. Public summaries of patent disputes in this area have involved multiple Tris Pharma amphetamine patents, not necessarily this patent alone. The commercial outcome is normally determined by the full patent family, claim scope, ANDA formulation and settlement terms.

What settlement agreements and generic launch scenarios matter?

A typical settlement structure for a controlled-substance extended-release product may include:

• A permitted generic launch date before patent expiration.
• A license limited to one manufacturer.
• No admission of infringement or validity.
• Restrictions on authorized-generic supply.
• Manufacturing or sourcing conditions.
• A consent judgment or dismissal of Hatch-Waxman litigation.

The principal launch scenarios are:

Scenario	Commercial result
Patent upheld and infringed	Generic launch is delayed until expiration or licensed entry
Patent invalidated	FDA approval may proceed after resolution of other listed patents
Noninfringement established	Generic can launch if no other patent or regulatory barrier remains
Settlement with licensed entry	Launch occurs on the negotiated date
Formulation redesign	Generic enters with a product outside the asserted claims
No Paragraph IV challenge	Entry waits for patent expiry or a different regulatory pathway

Because amphetamine products are Schedule II controlled substances, a generic sponsor also faces Drug Enforcement Administration controls, quota limitations, manufacturing requirements and supply-chain restrictions. These are not patent barriers, but they can affect launch timing and volume.

What manufacturing and geographic IP barriers apply?

The patent is a United States patent. Its direct exclusionary effect is limited to the United States, including U.S. manufacture, importation, sale, offers for sale and use within the statutory scope.

The formulation may require specialized manufacturing steps:

• Drug loading onto a cation-exchange resin.
• Particle-size control.
• Polymer incorporation into the resin-complex matrix.
• Uniform diffusion coating.
• Plasticizer control.
• Dissolution testing over an extended period.
• Suspension stabilization without damaging the coating.

These process requirements can create practical barriers even if a competitor avoids the patent. The most difficult scale-up variables are likely coating uniformity, drug loading, particle-size distribution and maintenance of the release profile after storage in an aqueous vehicle.

Foreign patent rights must be assessed separately. A U.S. patent does not establish protection in Europe, Canada, Japan or other markets. The relevant international family members, national-phase status, expiration dates and maintenance records determine geographic coverage.[1]

How does US 8,747,902 compare with competing amphetamine patent strategies?

Technology	Drug structure	Release mechanism	Relationship to US 8,747,902
US 8,747,902 formulation	Amphetamine or dextroamphetamine bound to cation-exchange resin	Polymer matrix plus diffusion coating and mixed-release fraction	Directly targeted
Adderall XR-type bead system	Mixed amphetamine salts in multiparticulate beads	Immediate-release and delayed-release bead populations	Potentially outside claim scope if no ion-exchange resin
Vyvanse	Lisdexamfetamine prodrug	Enzymatic conversion to dextroamphetamine	Chemically distinct
Osmotic tablet	Amphetamine salt in osmotic delivery system	Membrane and osmotic pumping	Usually outside resin-complex limitations
Conventional matrix tablet	Amphetamine dispersed in polymer matrix	Diffusion, erosion or swelling	Outside claims if no resin complex
Liquid suspension without coated resin	Free amphetamine or conventional particles	Vehicle or matrix-based release	Generally outside the independent claims

Key Takeaways

• US 8,747,902 is a formulation patent, not a molecule patent.
• Claims 1 and 19 cover solid oral compositions and aqueous suspensions, respectively.
• The required architecture combines coated amphetamine-resin particles with an uncoated or uncomplexed amphetamine fraction.
• The most important technical limitations are the water-insoluble cation-exchange resin, polymer matrix, nonionic diffusion coating, approximately 12-hour release profile and 125%-400% elongation factor.
• Claims 5-18 and 20-30 narrow protection to acrylic copolymers, plasticizers, coating percentages, strongly acidic resins and polyvinylpyrrolidone.
• Dyanavel XR is the product most directly aligned with the liquid-suspension claims.
• Adzenys XR-ODT may implicate the solid and orally dissolving tablet claims only if its particulate technology satisfies the resin and coating limitations.
• Adderall XR, Mydayis and Vyvanse are not automatically covered because extended release or dextroamphetamine alone is insufficient.
• The expected base patent-term endpoint is in December 2029, subject to the USPTO term calculation and any applicable adjustment.
• A Paragraph IV challenge would likely center on the resin-complex, coating, release-profile and mixed-release limitations.
• Controlled-substance manufacturing, DEA quota and scale-up requirements can delay generic commercialization independently of patent litigation.

Frequently Asked Questions

Does US 8,747,902 cover all extended-release amphetamine products?

No. The claims require a cation-exchange resin complex, a specified polymer matrix and diffusion coating, plus an additional uncoated or uncomplexed amphetamine component.

Can a generic avoid US 8,747,902 by using a different polymer?

Potentially. A different polymer may avoid a dependent claim directed to acrylic copolymers, but it must also be evaluated against the broader polymer and coating limitations in claims 1 and 19.

Does the patent cover immediate-release amphetamine by itself?

No. The patent requires an orally ingestible composition that includes the controlled-release coated particulate architecture. Uncomplexed amphetamine is an additional component, not the entire claimed product.

Is US 8,747,902 a method-of-use patent?

No. The asserted claims provided are composition claims covering dosage-form structure, materials and release characteristics.

Can a foreign manufacturer infringe this patent by exporting amphetamine suspension to the United States?

Potentially, if the imported product satisfies the claim limitations. U.S. patent law can reach importation and other commercial acts involving a patented composition, while foreign manufacture alone is governed by the laws of the country where it occurs.

References

1. U.S. Patent and Trademark Office. (2014). U.S. Patent No. 8,747,902, Extended release compositions. Washington, DC: U.S. Department of Commerce.

2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. Silver Spring, MD: FDA.

3. U.S. Food and Drug Administration. (2023). Abbreviated new drug application regulations and patent certifications. Silver Spring, MD: FDA.

4. U.S. Code, 35 U.S.C. §§ 102, 103, 112, 154 and 271. (2024). Patentability, patent term and infringement provisions. Washington, DC: U.S. Government Publishing Office.

Drugs Protected by US Patent 8,747,902

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Tris Pharma Inc	DYANAVEL XR	amphetamine; amphetamine aspartate/dextroamphetamine sulfate	SUSPENSION, EXTENDED RELEASE;ORAL	208147-001	Oct 19, 2015		RX	Yes	Yes	8,747,902		Y
Tris Pharma Inc	DYANAVEL XR 10	amphetamine; amphetamine aspartate/dextroamphetamine sulfate	TABLET, EXTENDED RELEASE;ORAL	210526-002	Nov 4, 2021		RX	Yes	No	8,747,902		Y
Tris Pharma Inc	DYANAVEL XR 15	amphetamine; amphetamine aspartate/dextroamphetamine sulfate	TABLET, EXTENDED RELEASE;ORAL	210526-003	Nov 4, 2021		RX	Yes	No	8,747,902		Y
Tris Pharma Inc	DYANAVEL XR 20	amphetamine; amphetamine aspartate/dextroamphetamine sulfate	TABLET, EXTENDED RELEASE;ORAL	210526-004	Nov 4, 2021		RX	Yes	Yes	8,747,902		Y
Tris Pharma Inc	DYANAVEL XR 5	amphetamine; amphetamine aspartate/dextroamphetamine sulfate	TABLET, EXTENDED RELEASE;ORAL	210526-001	Nov 4, 2021		RX	Yes	No	8,747,902		Y

International Family Members for US Patent 8,747,902

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	E536867
Australia	2007227569
Brazil	PI0709606
Canada	2645855
China	101400343
China	102488652