US Patent 9,173,857: Scope, Claims, Expiration, Orange Book Status, and Amphetamine Patent Landscape
US Patent 9,173,857 protects a multiparticulate mixed-amphetamine formulation used to treat ADHD. Its core limitation is a three-bead dosage form: one immediate-release bead, one delayed-release bead producing a pulse, and a second delayed-release bead producing sustained release through pH-independent and pH-dependent coating layers. The patent is associated with the Mydayis® extended-release mixed amphetamine salts product marketed by Shire, now part of Takeda.
The patent does not broadly cover every extended-release amphetamine product. Infringement generally requires a product and use that satisfy the detailed bead architecture, coating structure, release behavior, and ADHD-treatment limitations recited in claim 1.
What drug and product are associated with US Patent 9,173,857?
US Patent 9,173,857 is directed to extended-release mixed amphetamine salts for ADHD. The commercial product most closely associated with the claimed technology is Mydayis capsules, an extended-release formulation containing mixed amphetamine salts.
| Item |
Information |
| Patent |
US 9,173,857 B2 |
| Patent type |
Utility patent |
| Therapeutic area |
Attention deficit hyperactivity disorder |
| Active pharmaceutical ingredient |
Mixed amphetamine salts |
| Dosage form |
Multiparticulate extended-release capsule |
| Commercial product |
Mydayis |
| Original commercial sponsor |
Shire |
| Current corporate group |
Takeda |
| FDA regulatory pathway |
NDA approval |
| Controlled-substance category |
Schedule II |
| Principal patent subject |
Three-population bead system with pulsed and sustained release |
The FDA approved Mydayis extended-release capsules in 2017 for ADHD in patients age 13 years and older at the time of approval. The product contains four amphetamine salts: dextroamphetamine sulfate, dextroamphetamine saccharate, amphetamine aspartate monohydrate, and amphetamine sulfate.[1]
What does claim 1 of US 9,173,857 require?
Claim 1 is a method-of-treatment claim with multiple formulation limitations. A potentially infringing use must involve administering a pharmaceutical composition comprising all of the following:
- An immediate-release bead containing at least one amphetamine salt.
- A first delayed-release bead containing at least one amphetamine salt.
- A second delayed-release bead containing at least one amphetamine salt.
- A pulsed-release function from the first delayed-release bead.
- A sustained-release function from the second delayed-release bead.
- An amphetamine-containing core in the second delayed-release bead.
- A delayed-release coating on that core.
- A sustained-release coating over the delayed-release coating.
- A pH-independent sustained-release coating.
- Enteric coatings on both delayed-release bead populations.
- Administration to a patient for treatment of ADHD.
The claim therefore combines three separate concepts:
- Release timing: immediate, pulsed, and sustained.
- Physical construction: cores and sequential coating layers.
- Therapeutic use: administration for ADHD.
A formulation with only immediate release and one delayed-release population would not literally satisfy claim 1. A product with two delayed-release populations but no pH-independent sustained-release coating also would not literally satisfy the claim.
How do the dependent claims narrow the patent scope?
The dependent claims create alternative and increasingly specific embodiments.
| Claims |
Limitation |
| 2 |
Enteric coating is pH-dependent |
| 3 |
First and second delayed-release beads use different enteric coatings |
| 4 |
First and second delayed-release beads use the same enteric coating |
| 5 |
d-amphetamine Cmax of about 50 ng/mL after a 37.5 mg dose |
| 6 |
d-amphetamine AUC0-last of about 1,058 ng·hr/mL |
| 7 |
d-amphetamine AUC0-inf of about 1,085 ng·hr/mL |
| 8 |
d-amphetamine Tmax of about 8.2 hours |
| 9 |
l-amphetamine Cmax of about 15 ng/mL |
| 10 |
l-amphetamine AUC0-last of about 354 ng·hr/mL |
| 11 |
l-amphetamine AUC0-inf of about 373 ng·hr/mL |
| 12 |
l-amphetamine Tmax of about 8.4 hours |
| 13-14 |
Amphetamine salt coated onto or incorporated into a core |
| 15-16 |
Protective layer over or between coating layers |
| 17-18 |
Specific amphetamine salts and the four-salt mixture |
| 19 |
No food effect |
| 20-28 |
Dose strengths from 12.5 mg to 75 mg |
| 29 |
Protective coating between delayed-release and sustained-release coatings |
Claims 3 and 4 are alternative claim branches. A formulation can use different enteric coatings or the same enteric coating. Claims 15, 16, and 29 add protective or separating layers that can become important in product-by-product infringement analysis.
What formulations are protected by US 9,173,857?
The strongest formulation coverage is directed to a multiparticulate capsule containing three functional bead classes.
Immediate-release beads
The immediate-release beads provide an initial amphetamine exposure after administration. Claim 1 does not specify a particular coating architecture for these beads.
Pulsed delayed-release beads
The first delayed-release population is designed to release amphetamine after a delay and then provide a pulse. The claim does not prescribe a single dissolution profile or a specific enteric polymer. The functional requirement is pulsed release.
Sustained delayed-release beads
The second delayed-release population has the most detailed structure. Amphetamine is layered onto or incorporated into a core. A delayed-release coating surrounds the amphetamine-containing region, and a pH-independent sustained-release coating is applied over the delayed-release coating.
The second delayed-release bead also has an enteric coating. The claim language creates a layered release system in which gastrointestinal pH triggers part of the release behavior, while the sustained-release layer regulates release independently of pH.
Amphetamine salts
Claim 17 identifies:
- Dextroamphetamine sulfate
- Dextroamphetamine saccharate
- Amphetamine aspartate monohydrate
- Amphetamine sulfate
Claim 18 narrows the composition to a mixture of all four salts. That combination corresponds to the mixed amphetamine salts composition used in Mydayis and other amphetamine products.
How important are the pharmacokinetic claims?
Claims 5 through 12 provide narrower protection based on pharmacokinetic parameters after administration of a 37.5 mg dose.
The claimed values include:
| Parameter |
d-Amphetamine |
l-Amphetamine |
| Cmax |
About 50 ng/mL |
About 15 ng/mL |
| AUC0-last |
About 1,058 ng·hr/mL |
About 354 ng·hr/mL |
| AUC0-inf |
About 1,085 ng·hr/mL |
About 373 ng·hr/mL |
| Tmax |
About 8.2 hours |
About 8.4 hours |
These claims can strengthen enforcement if a competing product produces substantially similar exposure. They also create litigation issues because the scope of terms such as “about,” the test population, dose administration conditions, bioanalytical methods, and statistical variation may become material.
A product may avoid a literal infringement finding under the pharmacokinetic claims while still potentially implicating claim 1. Conversely, a product could have similar PK characteristics but avoid infringement if its bead architecture does not meet the structural limitations of claim 1.
When does US Patent 9,173,857 lose exclusivity?
The commonly reported expiration date for US 9,173,857 is March 8, 2032, subject to patent-term adjustment and any applicable regulatory extensions reflected in official records.[2][3]
| Milestone |
Date or status |
| Patent number |
9,173,857 |
| Grant |
2016 |
| Reported expiration |
March 8, 2032 |
| Patent-term adjustment |
Must be confirmed in the USPTO patent record |
| Pediatric exclusivity |
May extend applicable FDA exclusivity by six months if granted for the relevant product |
| Orange Book status |
Associated with the Mydayis NDA listing |
Patent expiration does not automatically mean generic entry on the same day. FDA regulatory exclusivity, other listed patents, litigation stays, court judgments, and settlement terms can affect the launch date.
What is the Orange Book status of US 9,173,857?
US 9,173,857 has been associated with the Orange Book patent listing for Mydayis, an extended-release mixed amphetamine salts product.[3] Orange Book listing is commercially important because an ANDA applicant referencing the drug may need to certify against the listed patent.
A Paragraph IV certification would assert that the patent is invalid, unenforceable, or will not be infringed by the proposed generic product. The patent’s formulation-specific scope gives an ANDA applicant several design-around paths, but each must be assessed against the complete claim set.
The Orange Book record should be reviewed together with:
- The listed patent expiration date.
- Any pediatric exclusivity.
- The relevant reference-listed drug and strengths.
- Other patents listed for the same NDA.
- The date and content of any Paragraph IV notice.
- Any 30-month stay arising from patent litigation.
Which companies are challenging the Mydayis patent estate?
The supplied information does not establish a verified Paragraph IV filer, litigation defendant, settlement agreement, or court judgment specifically involving US 9,173,857. A reliable competitive assessment must distinguish between:
- A company developing a mixed amphetamine salts product.
- An ANDA applicant that has filed a Paragraph IV certification.
- A defendant named in patent litigation.
- A settlement party with an agreed launch date.
Generic competition to Mydayis is distinct from competition to Adderall XR. An ANDA referencing Mydayis must address the listed drug’s extended-release properties and may need to demonstrate pharmaceutical equivalence, bioequivalence, and appropriate labeling under the ANDA pathway.[4]
What generic entry risks exist for Mydayis?
The main generic entry risk is a design-around formulation that avoids the claimed three-population architecture while preserving a comparable clinical effect.
Potential design-around strategies could include:
- Using a different number of bead populations.
- Replacing bead technology with a matrix system.
- Using a single modified-release population.
- Changing the order or composition of coating layers.
- Using a sustained-release mechanism that is pH-dependent rather than pH-independent.
- Eliminating the claimed enteric coating structure.
- Using a different amphetamine salt ratio.
- Producing a different PK profile outside the narrower dependent claims.
The central litigation risk is claim 1. Because claim 1 is a method claim, a generic product may face induced-infringement allegations if its labeling instructs treatment of ADHD using a composition that satisfies the formulation limitations.
A generic applicant may also challenge validity based on anticipation or obviousness. Relevant prior-art categories would include:
- Multiparticulate amphetamine formulations.
- Enteric-coated drug beads.
- Pulsatile release systems.
- pH-independent sustained-release coatings.
- Mixed amphetamine salt formulations.
- Prior clinical and pharmacokinetic disclosures.
The claim’s combination of release functions and coating architecture may provide stronger protection than a claim directed only to the active ingredient or dosage strength.
How does US 9,173,857 compare with other ADHD stimulant patents?
| Product |
Active ingredient |
Release platform |
Principal patent risk |
| Mydayis |
Mixed amphetamine salts |
Immediate, pulsed delayed, and sustained beads |
Multiparticulate formulation and method claims |
| Adderall XR |
Mixed amphetamine salts |
Immediate-release and delayed-release bead technology |
Earlier mixed-amphetamine bead patents |
| Vyvanse |
Lisdexamfetamine |
Prodrug converted to dextroamphetamine |
Composition, prodrug, and method patents |
| Jornay PM |
Methylphenidate HCl |
Evening-dosed delayed and extended release |
Chronotherapeutic release profile |
| Azstarys |
Serdexmethylphenidate and dexmethylphenidate |
Prodrug plus immediate-release stimulant |
Composition and formulation patents |
| Dyanavel XR |
Amphetamine |
Extended-release liquid |
Liquid formulation and release patents |
US 9,173,857 is differentiated by its claimed combination of three release populations. It is not a patent on amphetamine as an active ingredient, ADHD treatment generally, or all extended-release stimulant products.
Does the patent create biosimilar risk?
No. Mydayis is a small-molecule drug, not a biologic. A competing product would proceed through the generic-drug framework, principally an ANDA under section 505(j) of the Federal Food, Drug, and Cosmetic Act, rather than through the biosimilar pathway under section 351(k) of the Public Health Service Act.[4][5]
The relevant competitive threats are generic amphetamine products, formulation design-arounds, and competing branded ADHD stimulants. Biosimilar substitution principles do not apply.
How strong is the patent estate for US 9,173,857?
US 9,173,857 has moderate-to-strong value against products that copy the Mydayis release design. Its strength comes from the combination of:
- Three distinct bead populations.
- A required pulsed-release bead.
- A sustained-release bead with sequential coating layers.
- A pH-independent sustained-release coating.
- Enteric coating limitations.
- Specific mixed amphetamine salt embodiments.
- ADHD treatment use.
- PK-defined dependent claims.
Its limitations also create design-around opportunities. The patent is less effective against a product using a different delivery platform, different bead count, different coating sequence, or materially different release mechanism.
The patent does not, by itself, establish exclusivity over all mixed amphetamine salts, all ADHD formulations, or all products with an approximately eight-hour Tmax.
What patent litigation and settlement issues should investors monitor?
The key events are:
- Paragraph IV certifications against the Mydayis Orange Book listings.
- ANDA litigation filed within 45 days of a Paragraph IV notice.
- A potential 30-month FDA approval stay.
- Claim-construction rulings concerning “pulsed release,” “sustained release,” “pH-independent,” and “about.”
- Expert disputes over coating architecture and dissolution testing.
- Settlements establishing an authorized-generic or first-entrant launch date.
- FDA approval of a generic mixed amphetamine salts extended-release product referencing Mydayis.
Revenue exposure is concentrated in Mydayis sales because the patent does not protect the broader amphetamine market. Generic entry could affect the product’s price, formulary position, and prescription share, but competing products such as Vyvanse, Adderall XR, Jornay PM, and Azstarys limit the addressable market even before patent expiry.
Key Takeaways
- US 9,173,857 is a formulation and method-of-treatment patent associated with Mydayis.
- Claim 1 requires immediate-release, pulsed delayed-release, and sustained delayed-release amphetamine beads.
- The sustained-release bead must include a delayed-release coating and a pH-independent sustained-release coating.
- The patent covers specific mixed amphetamine salts, including the four-salt combination used in Mydayis.
- Claims 5 through 12 add narrower d-amphetamine and l-amphetamine PK limitations.
- The commonly reported patent expiration date is March 8, 2032, subject to official patent-term calculations.
- The patent is relevant to Orange Book and Paragraph IV analysis for generic Mydayis.
- The principal generic strategy is a formulation design-around rather than a direct copy of the claimed bead architecture.
- Mydayis is a small-molecule product, so biosimilar litigation is not applicable.
- The patent does not cover every extended-release amphetamine or every ADHD stimulant.
FAQs
What is the main inventive concept in US Patent 9,173,857?
The main concept is a three-population multiparticulate formulation combining immediate release, delayed pulsed release, and delayed sustained release in one ADHD treatment composition.
Does US 9,173,857 cover Adderall XR?
Not automatically. Adderall XR and Mydayis both use mixed amphetamine salts and multiparticulate release technology, but infringement depends on whether the accused product satisfies every limitation of an asserted claim.
Can a generic avoid US 9,173,857 by using a tablet instead of beads?
Potentially. A tablet or matrix product may avoid literal infringement of bead-specific limitations, although other patents, labeling theories, or equivalents arguments could remain relevant.
Are the claimed 37.5 mg pharmacokinetic values required for every infringement case?
No. They are limitations of dependent claims 5 through 12. Claim 1 does not require the specific PK values stated in those claims.
Does patent expiration guarantee immediate generic availability?
No. FDA approval requirements, other Orange Book patents, pediatric exclusivity, litigation stays, and settlement agreements can affect the actual launch date.
References
- U.S. Food and Drug Administration. (2017). FDA approves new treatment option for ADHD. https://www.fda.gov
- United States Patent and Trademark Office. (2016). U.S. Patent No. 9,173,857, pharmaceutical compositions and methods of treatment. https://patents.google.com
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugsatfda
- U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application process. https://www.fda.gov
- U.S. Food and Drug Administration. (n.d.). Biosimilar and interchangeable biologic products. https://www.fda.gov
