Details for Patent: 9,017,731

Which drugs does patent 9,017,731 protect, and when does it expire?

Patent 9,017,731 protects ADZENYS ER and ADZENYS XR-ODT and is included in two NDAs.

This patent has two patent family members in two countries.

Summary for Patent: 9,017,731

Title:	Composition comprising a mixture of dextro- and levo-amphetamines complexed with ion-exchange resin particles to form drug resin particles
Abstract:	The invention relates to dosage forms that provide prolonged therapy. In particular, the invention relates to dosage forms including various pluralities of drug-containing resin particles. In a particular embodiment, the drug dosage form comprises a mixture of dextro- and levo-amphetamines complexed with ion-exchange resin particles to form drug resin particles. The invention also relates to methods of making these dosage forms and methods of treating using these dosage forms.
Inventor(s):	Mark Tengler, Russell McMahen
Assignee:	Neos Therapeutics LP
Application Number:	US13/844,537
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 9,017,731
Patent Claim Types: see list of patent claims	Composition; Formulation; Compound; Dosage form;

United States Patent 9,017,731: Claim Scope, Patent Strength, Exclusivity and Generic Entry Risk

U.S. Patent No. 9,017,731 protects multiparticulate extended-release amphetamine compositions using two populations of ion-exchange resin particles: an uncoated immediate-release fraction and a delayed-release coated fraction. The strongest commercial claims target mixed amphetamine products formulated as oral suspensions or orally disintegrating tablets, particularly products that reproduce specified dissolution, pharmacokinetic, food-effect, and ethanol-exposure profiles.

The patent is structurally difficult to design around if a competing product uses the same resin-based dual-population architecture. It is easier to avoid claims that depend on precise release ratios, specific plasma exposure values, food effects, two-peak profiles, or particular dosage forms.

What does U.S. Patent 9,017,731 cover?

The patent covers pharmaceutical compositions containing dextroamphetamine and levoamphetamine complexed with ion-exchange resin particles. The composition must include:

1. A first population of uncoated drug-resin particles.
2. A second population of drug-resin particles with a delayed-release coating.
3. Amphetamine drug content distributed between those populations.
4. In several claims, a particular release profile, dosage form, pharmacokinetic profile, food effect, or ethanol-related exposure characteristic.

The broadest architectural claim is claim 1. It requires that 30% to 50% by weight of the amphetamines be in the uncoated particles and 50% to 70% be in the delayed-release coated particles.

The claim uses "comprising," which generally permits additional ingredients, excipients, coatings, particle populations, or processing elements unless those additions alter another claim limitation. The claim therefore does not require a composition to contain only the listed components.

Core technical architecture

Element	Claim requirement
Active drug	Mixture of dextro- and levo-amphetamines
Drug carrier	Ion-exchange resin particles
First particle population	Uncoated drug-resin particles
Second particle population	Drug-resin particles with delayed-release coating
Broad ratio	30% to 50% uncoated; 50% to 70% coated
Narrow ratio	40% to 50% uncoated; 50% to 60% coated
Approximate preferred ratio	About 45% uncoated; about 55% coated
Alternative ratio	About 50% uncoated; about 50% coated
Release trigger	In some claims, pH change
Dosage forms	Liquid suspension, chewable composition, or orally disintegrating tablet
Amphetamine stereochemistry	25% levoamphetamine and 75% dextroamphetamine in one dependent claim
Dose range	2 mg to 60 mg in one dependent claim

How do claims 1 through 11 define the formulation?

Claims 1 through 11 establish the principal formulation and dissolution claim set.

Claim 1: dual-population resin composition

Claim 1 is the principal composition claim. Literal infringement generally requires all of the following:

• Both dextro- and levo-amphetamines are present.
• The amphetamines are complexed with ion-exchange resin particles.
• One particle population is uncoated.
• A second particle population has a delayed-release coating.
• The uncoated population contains 30% to 50% by weight of the amphetamine.
• The coated population contains 50% to 70% by weight of the amphetamine.

The percentages are stated by weight of the amphetamine, not necessarily by total composition weight and not necessarily by total particle weight. That distinction matters in formulation testing and claim construction.

A product with a 49% immediate-release fraction and a 51% delayed-release fraction would fall within the stated range, assuming the other limitations are met. A product with 20% uncoated and 80% coated drug would fall outside the literal numerical scope of claim 1, although other claims or the doctrine of equivalents could remain relevant.

Claims 2 and 3: pH-triggered coatings

Claim 2 narrows the delayed-release coating to a triggered-release coating activated by a pH change. Claim 3 lists coating materials, including:

• Cellulose acetate phthalate
• Cellulose acetate trimellitate
• Hydroxypropyl methylcellulose phthalate
• Polyvinyl acetate phthalate
• Carboxymethylethylcellulose
• Methacrylic acid/methacrylic acid methyl ester copolymers
• Methacrylic acid/acrylic acid ethyl ester copolymers
• Mixtures of those materials

These claims create a formulation-specific pathway to infringement. A competitor can reduce literal risk by using a delayed-release mechanism that is not pH-triggered, such as a different polymer system, a diffusion-controlled coating, a matrix formulation, or a mechanically engineered release system. That approach may create separate regulatory and manufacturing issues.

Claim 4: resin species

Claim 4 identifies strong acidic cation-exchange resins, including:

• Polistirex
• Polacrilex
• Cholestyramine
• Polacrilin
• Mixtures of those resins

The claim is not limited to one resin. A product using a listed resin presents a direct infringement risk if the remaining limitations are met. A product using a different ion-exchange resin may avoid literal infringement of claim 4, but it could still fall within claim 1 because claim 1 does not identify a particular resin chemistry.

Claims 5, 6 and 19: particle-population ratios

Claims 5 and 6 narrow the allocation to 40% to 50% uncoated and 50% to 60% coated, with claim 6 identifying approximately 45% and 55%.

Claim 19 separately claims approximately 50% uncoated and 50% coated. The overlapping ratio claims give the patent holder multiple positions around the apparent target formulation. A competitor that moves modestly away from a 45/55 formulation may still remain within claim 1 or claim 5.

Claims 7 through 9: dosage form, stereochemistry and dose

Claim 7 covers liquid suspensions, chewable compositions, and orally disintegrating tablets. These dosage-form limitations are important because the patent does not rely solely on a conventional solid extended-release tablet.

Claim 8 requires a 25:75 levoamphetamine-to-dextroamphetamine ratio. That ratio corresponds to the stereochemical balance associated with mixed amphetamine products.

Claim 9 covers a total amphetamine amount of 2 mg to 60 mg. This range encompasses common pediatric and adolescent dose strengths, as well as several adult dosing configurations.

Claims 10 and 11: dissolution performance

Claim 10 requires a defined in vitro release sequence:

• 40% to 45% release during the first 45 minutes.
• Substantially no release from 45 minutes to two hours.
• Substantially all remaining drug release during the two- to eight-hour period.
• Initial medium of 0.1 N hydrochloric acid.
• Adjustment to approximately pH 6.8 after two hours.
• USP Apparatus 2 testing.

This claim is commercially significant because dissolution testing can be performed on a finished product. It gives the patent holder a potentially direct way to compare a generic product against the claimed performance without resolving every manufacturing detail.

Claim 11 requires substantially complete release from the delayed-release population within approximately 60 minutes after delayed release begins. A product with a materially slower second-phase release may avoid this claim while still presenting risk under broader composition claims.

What do claims 12 through 20 protect?

Claims 12 through 20 extend the patent beyond physical formulation structure. They claim performance characteristics that may be difficult to assess without access to development data, clinical data, or a regulatory submission.

Ethanol-resistant exposure

Claim 12 covers a composition that reduces amphetamine exposure in the presence of ethanol compared with a non-resin reference composition. This claim is directed to an alcohol-interaction property of the resin complex.

The claim does not require a particular percentage reduction. The comparison is against a composition without resin particles containing the same specified mixture of amphetamine salts. The absence of a numerical threshold may broaden the claim but also creates potential indefiniteness and proof issues concerning the meaning of "reduced amount."

Reference-dose claim

Claim 13 refers to doses equivalent to 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, or 30 mg of a reference mixed-amphetamine composition. It ties the claimed resin formulation to standard amphetamine dose strengths.

Orally disintegrating tablet pharmacokinetics

Claim 14 covers an orally disintegrating tablet that produces specified dextroamphetamine and levoamphetamine exposure values for a 30 mg dose. The claimed parameters include AUC and Cmax over several intervals, including:

• AUC0-4
• AUC0-5
• AUC4-12
• AUC5-12
• AUC0-24

The specified tolerances are generally -20% to +25%. The claim also provides for proportional values at doses other than 30 mg.

This claim is potentially powerful against a product that reproduces the same ODT pharmacokinetic profile. It is less useful against a product with the same structural formulation but materially different exposure.

Liquid-suspension pharmacokinetics

Claim 15 covers a liquid suspension with separate dextroamphetamine and levoamphetamine AUC and Cmax values. The values differ from those in claim 14, recognizing that an oral suspension may produce a different absorption profile from an ODT.

The distinction between claims 14 and 15 creates separate patent positions for two commercially relevant dosage forms.

Total amphetamine exposure

Claim 16 requires an AUC0-infinity of approximately 1,140 to 1,240 for total amphetamines at a 30 mg dose. This claim is broader than the stereospecific PK claims in claims 14 and 15 because it aggregates dextroamphetamine and levoamphetamine.

Bioequivalence-type performance

Claim 17 requires one or more pharmacokinetic parameters to have a 90% confidence interval within 90% to 115% of a bioequivalent reference composition. This is a narrow performance claim based on statistical bioequivalence criteria.

The claim could be important in an ANDA dispute because a generic applicant may generate precisely the type of comparative PK data needed to establish infringement. Its weakness is that it depends on the selected reference composition and statistical study design.

Food effect

Claim 18 covers a liquid suspension that produces increased early amphetamine exposure when administered substantially contemporaneously with food, compared with a non-resin reference composition under similar food conditions.

The claim is directed to the first four hours after dosing. A competing product with a different fed-state absorption profile may avoid this claim, even if its overall exposure and release mechanism are similar.

Two-peak fasted profile

Claim 20 requires a fasted serum profile with:

• A first peak at one to three hours.
• A second peak at four to seven hours.
• The second peak being the Cmax.

This claim maps directly onto a dual-release design. A competing product with a single peak, a first peak outside the one- to three-hour window, or a second peak outside the four- to seven-hour window may avoid literal infringement.

What patent claims are most commercially important?

The claims can be ranked by practical enforcement value.

Claim group	Commercial relevance	Main proof required
Claims 1, 5, 6 and 19	High	Product composition and particle ratios
Claims 2 through 4	Moderate to high	Coating trigger and resin identity
Claims 7 through 9	High for product matching	Dosage form, dose and stereochemical composition
Claims 10 and 11	High	Controlled dissolution testing
Claim 12	Moderate	Ethanol-comparison testing
Claims 14 through 16	Moderate to high	Clinical or comparative PK data
Claim 17	High in ANDA litigation	Bioequivalence study and statistical analysis
Claim 18	Moderate	Fed-state clinical PK data
Claim 20	High where dual peaks are reproduced	Fasted serum concentration-time data

Claims 1, 10 and 11 are likely to be the central claims in a formulation dispute. Claims 14 through 18 are more dependent on clinical or comparative testing and may be harder to prove before an accused product reaches the market.

When does U.S. Patent 9,017,731 lose exclusivity?

The patent term is generally measured from the earliest effective nonprovisional filing date in the relevant priority chain, not from the issue date. Public patent records associate the patent with a late-2020s expiration framework, subject to patent term adjustment and any applicable regulatory extension. The patent should therefore be treated as a live U.S. formulation patent through at least the late 2020s unless the USPTO term record, terminal disclaimer, disclaimer filing, or litigation judgment changes that conclusion. [1]

Exclusivity timeline

Event	Timing
Earliest priority filings	Pre-issuance priority chain
U.S. patent application	Before issuance
Patent issued	April 28, 2015
Patent term	Twenty years from the applicable earliest nonprovisional filing date, adjusted under 35 U.S.C. §§ 154 and 156
Expected base-term window	Late 2020s
Regulatory exclusivity	Separate from patent term and dependent on the approved NDA
Generic entry	Controlled by patent term, listed claims, ANDA certifications, litigation and any settlement

A precise commercial entry date cannot be inferred from the issue date alone. A patent term adjustment calculation and current Orange Book listing are required to establish the operative date.

What is the Orange Book status of the patent?

A patent's appearance in the Orange Book depends on the approved drug product and the NDA holder's listing submission. The Orange Book may list the patent for a specific dosage form, strength, or method of use rather than for every product that might technically practice the claims. [2]

The patent's formulation claims are most relevant to mixed amphetamine products using:

• Ion-exchange resin complexes.
• Immediate-release and delayed-release particle populations.
• Oral suspensions.
• Orally disintegrating tablets.
• Extended-release mixed amphetamine salts.

Orange Book listing does not itself establish infringement. It determines whether an ANDA applicant must address the patent through a Paragraph III certification, Paragraph IV certification, or another applicable certification.

How does a Paragraph IV challenge affect generic entry?

An ANDA applicant challenging a listed patent may submit a Paragraph IV certification asserting that the patent is invalid, unenforceable, or not infringed. The NDA holder can sue within the statutory period, triggering an automatic stay of FDA approval for up to 30 months, subject to statutory exceptions and court developments. [3]

For this patent, likely Paragraph IV positions would include:

Non-infringement arguments

A generic applicant could argue that its product:

• Does not use ion-exchange resin particles.
• Uses only one particle population.
• Uses a coated fraction outside the claimed weight ranges.
• Uses a delayed-release mechanism that is not covered by the asserted dependent claims.
• Does not contain both dextro- and levo-amphetamines in the claimed configuration.
• Does not meet the claimed dissolution or PK limitations.
• Does not produce the claimed two-peak fasted profile.

Invalidity arguments

Potential validity challenges include:

• Anticipation by earlier amphetamine resin formulations.
• Obviousness based on combining ion-exchange resin technology with known extended-release amphetamine products.
• Lack of written description for broad combinations of resin types, coatings, dosage forms and PK profiles.
• Enablement concerns for the full breadth of the claimed genus.
• Indefiniteness involving terms such as "about," "substantially no release," "reduced amount," and "directly proportional."
• Lack of novelty or obviousness for the specified dissolution and two-peak profiles.

A successful Paragraph IV case would require more than showing that the general idea of resin-based extended release was known. The challenger would need to address the combination of particle populations, numerical drug allocation, coating system, drug composition and, where applicable, performance limitations.

Which companies are challenging the patent?

The patent claims alone do not identify an ANDA applicant, Paragraph IV filer, settlement party or litigant. Those entities must be established from current FDA Orange Book data, FDA Paragraph IV notices, district court complaints and docket records. Patent ownership, NDA sponsorship and generic challenge status are separate records.

The relevant commercial parties are likely to include:

• The patent owner or exclusive licensee.
• The NDA holder for the covered mixed amphetamine product.
• Generic manufacturers developing extended-release mixed amphetamine products.
• Contract manufacturers supplying resin-based multiparticulates.
• Companies developing non-resin or alternative extended-release amphetamine products.

No challenger, litigation outcome or settlement term should be attributed solely from the claim language.

How strong is the patent estate?

The estate is strongest against a formulation that deliberately reproduces the disclosed platform:

• Mixed dextroamphetamine and levoamphetamine.
• Ion-exchange resin complexation.
• Approximately 45/55 or 50/50 immediate-release and delayed-release drug allocation.
• pH-triggered coating.
• Oral suspension or ODT.
• Dual-peak fasted profile.
• Similar dissolution and PK behavior.

The estate is weaker against products that move away from the platform's defining combination.

Strength assessment

Risk area	Assessment
Structural coverage of dual-population resin products	Strong
Coverage of exact 45/55 or 50/50 ratios	Strong but fact-dependent
Coverage of alternative resins	Moderate to strong under broad claims
Coverage of non-pH delayed release	Depends on asserted claim
Coverage of non-resin extended release	Low under the supplied claims
Coverage based on dissolution testing	Moderate to strong
Coverage based on PK profiles	Moderate, with substantial proof burden
Coverage of different stereochemical ratios	Potentially limited
Coverage of single-peak products	Limited under claim 20
Exposure to obviousness attacks	Material
Exposure to indefiniteness attacks	Material for functional and approximate terms

What formulations are protected, and how can competitors design around them?

The most direct design-arounds are:

1. Use a non-resin controlled-release system, such as a polymer matrix or coated crystal technology.
2. Use a single population of coated particles with programmed release rather than separate uncoated and coated populations.
3. Place less than 30% or more than 50% of the amphetamine in the uncoated fraction.
4. Use an alternative active-ingredient ratio that does not satisfy the relevant stereochemical limitation.
5. Use a delayed-release mechanism that does not rely on a listed pH-triggered coating.
6. Develop a dosage form outside the expressly recited liquid, chewable and ODT categories, subject to the scope of the asserted independent claim.
7. Produce a single-peak or materially different PK profile.
8. Use a release profile that does not satisfy the 40% to 45% early-release and two-hour plateau requirements.

The first three approaches provide the clearest structural separation. Changing only the coating polymer may not be sufficient because claim 1 broadly requires a delayed-release coating without limiting the coating chemistry.

What manufacturing and intellectual-property barriers exist?

The patent is not the only barrier to entry. A competing manufacturer must also reproduce or control:

• Resin particle size distribution.
• Amphetamine loading onto the resin.
• Coating thickness and uniformity.
• Release behavior across pH conditions.
• Suspension sedimentation and redispersibility.
• ODT taste masking and disintegration.
• Dose uniformity.
• Stability of the resin-drug complex.
• Ethanol interaction behavior.
• Fed and fasted pharmacokinetic performance.

These process variables can create manufacturing know-how barriers even where a competitor avoids literal infringement. They can also support separate trade-secret, process-patent or formulation-patent positions.

How does this patent compare with conventional extended-release amphetamine protection?

Conventional extended-release amphetamine patents generally focus on polymer matrices, coated beads, osmotic systems, dosage-form construction, or release schedules. U.S. Patent 9,017,731 is differentiated by its combination of:

• Ionic drug-resin complexation.
• Separate uncoated and delayed-release populations.
• Mixed amphetamine stereoisomers.
• Oral liquid and ODT formats.
• Defined alcohol, food, dissolution and PK behavior.

That combination can make the patent more relevant to abuse-deterrent or abuse-mitigating liquid and ODT products than a conventional tablet patent. It also creates multiple infringement theories, although each theory depends on the evidence available for the accused product.

Key Takeaways

• U.S. Patent 9,017,731 is directed to dual-population amphetamine ion-exchange resin formulations.
• Claim 1 is the principal broad composition claim and requires both uncoated and delayed-release drug-resin particles.
• The central numerical range is 30% to 50% of amphetamine in the uncoated fraction and 50% to 70% in the coated fraction.
• Claims 10 and 11 add dissolution-based protection.
• Claims 14 through 18 add dosage-form, PK, bioequivalence, food-effect and ethanol-exposure limitations.
• Claim 20 targets a fasted two-peak serum profile.
• The patent presents the greatest risk to products that reproduce the resin-based 45/55 or 50/50 architecture.
• Non-resin systems, single-population systems and materially different release profiles offer the clearest design-around strategies.
• Paragraph IV risk depends on the current Orange Book listing, ANDA certification, litigation status and any settlement agreement, none of which can be established from claim text alone.
• The patent should be treated as potentially enforceable through the late 2020s, subject to the official USPTO term calculation and regulatory records.

Frequently Asked Questions

Does U.S. Patent 9,017,731 cover all extended-release amphetamine products?

No. The supplied claims require amphetamine complexed with ion-exchange resin particles and, in the principal claims, separate uncoated and delayed-release particle populations.

Does using a different ion-exchange resin avoid infringement?

Not necessarily. Claim 1 is not limited to a particular resin. A different resin may avoid claim 4 but still infringe claim 1 if the remaining limitations are met.

Can a generic avoid the patent by changing the immediate-release percentage?

Potentially. Moving outside the 30% to 50% uncoated range may avoid literal infringement of claim 1, but the product must also be assessed against claims with different ratio language and the doctrine of equivalents.

Are the pharmacokinetic claims automatically infringed by bioequivalence?

No. Bioequivalence to a reference product does not automatically establish infringement of every PK claim. The relevant AUC, Cmax, time intervals, confidence intervals, dose, dosage form and reference composition must all be evaluated.

Does the patent protect abuse-deterrent amphetamine products?

The claims include an ethanol-related reduced-exposure limitation, but they do not broadly cover every abuse-deterrent amphetamine product. The product must satisfy the resin-particle and release-architecture limitations stated in the applicable claim.

References

1. United States Patent and Trademark Office. (2015). U.S. Patent No. 9,017,731, pharmaceutical composition claims. https://patents.google.com/patent/US9017731B2/en
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
3. U.S. Food and Drug Administration. (2024). Abbreviated new drug application regulations and patent certifications. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-314
4. U.S. Code. (2024). 35 U.S.C. §§ 154 and 156, patent term and patent term extension. https://uscode.house.gov/
5. U.S. Food and Drug Administration. (2024). Orange Book patent and exclusivity information. https://www.fda.gov/drugs/development-resources/orange-book-data-files-contained-orange-book-exclusivity-patent-and-approval-data-files

Drugs Protected by US Patent 9,017,731

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Neos Theraps Inc	ADZENYS ER	amphetamine	SUSPENSION, EXTENDED RELEASE;ORAL	204325-001	Sep 15, 2017		DISCN	Yes	No	9,017,731		Y
Neos Theraps	ADZENYS XR-ODT	amphetamine	TABLET, ORALLY DISINTEGRATING, EXTENDED RELEASE;ORAL	204326-001	Jan 27, 2016	AB	RX	Yes	No	9,017,731		Y
Neos Theraps	ADZENYS XR-ODT	amphetamine	TABLET, ORALLY DISINTEGRATING, EXTENDED RELEASE;ORAL	204326-002	Jan 27, 2016	AB	RX	Yes	No	9,017,731		Y
Neos Theraps	ADZENYS XR-ODT	amphetamine	TABLET, ORALLY DISINTEGRATING, EXTENDED RELEASE;ORAL	204326-003	Jan 27, 2016	AB	RX	Yes	No	9,017,731		Y
Neos Theraps	ADZENYS XR-ODT	amphetamine	TABLET, ORALLY DISINTEGRATING, EXTENDED RELEASE;ORAL	204326-004	Jan 27, 2016	AB	RX	Yes	No	9,017,731		Y

International Family Members for US Patent 9,017,731

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	2726066
World Intellectual Property Organization (WIPO)	2013003622