Details for Patent: 8,563,033

Which drugs does patent 8,563,033 protect, and when does it expire?

Patent 8,563,033 protects QUILLIVANT XR and is included in one NDA.

This patent has nine patent family members in eight countries.

Summary for Patent: 8,563,033

Title:	Orally effective methylphenidate extended release powder and aqueous suspension product
Abstract:	An oral methylphenidate powder which is reconstitutable into a final oral aqueous sustained release formulation containing at least about 50%, or at least about 80% by weight water based on the total weight of the suspension, is provided. The powder is a blend containing a combination of an uncoated methylphenidate—ion exchange resin complex, a barrier coated methylphenidate—ion exchange resin complex—matrix, and a water soluble buffering agent such that upon formed into an aqueous liquid formulation, the formulation has a pH in the range of about 3.5 to about 5, or about 4 to about 4.5. Following administration of a single dose of the oral aqueous methylphenidate suspension, a therapeutically effective amount of methylphenidate is reached in less than one hour and the composition provides a twelve-hour extended release profile.
Inventor(s):	Ketan Mehta, Yu-Hsing Tu, Ashok Perumal
Assignee:	Tris Pharma Inc
Application Number:	US13/905,808
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,563,033
Patent Claim Types: see list of patent claims	Use; Dosage form;

United States Patent 8,563,033: Methylphenidate Extended-Release Suspension Patent Scope and Landscape

US Patent 8,563,033 protects an aqueous, orally administered methylphenidate suspension that combines immediate-release and sustained-release drug fractions and produces one plasma concentration peak over approximately 12 hours. The claims are directed to the formulation, defined pharmacokinetic profile, pH, excipients, dose-specific performance, and treatment method.

The patent is commercially relevant to Quillivant XR, an extended-release methylphenidate hydrochloride oral suspension. The principal entry risk is an abbreviated new drug application, or ANDA, challenging the formulation and pharmacokinetic limitations under Paragraph IV. Biosimilar approval is not relevant because methylphenidate is a chemically synthesized small-molecule drug.

What drug and technology does US Patent 8,563,033 protect?

US 8,563,033 protects an extended-release methylphenidate oral suspension containing:

• An immediate-release methylphenidate component;
• A sustained-release methylphenidate component;
• Water;
• An acidic pH, generally 3.5 to 5.0;
• A pharmacokinetic profile producing a single average methylphenidate peak;
• Approximately 12 hours of therapeutic activity.

The patent is assigned to NextWave Pharmaceuticals, Inc., the developer associated with Quillivant XR. The product was subsequently commercialized by Tris Pharma and its affiliates.

The patent does not claim methylphenidate generally. Immediate-release tablets, sustained-release tablets, capsules, transdermal systems, and aqueous suspensions outside the claimed composition and pharmacokinetic parameters are outside the literal scope of the independent claims.

What is the commercial product associated with the patent?

Quillivant XR is methylphenidate hydrochloride extended-release oral suspension approved by the FDA for attention-deficit/hyperactivity disorder. The product is supplied as a powder that is reconstituted with water before oral administration. The product label identifies methylphenidate hydrochloride as the active ingredient and describes once-daily administration with approximately 12 hours of effect. [2]

The patent claims are directed to the final aqueous suspension and its performance. That distinction matters because a generic applicant may need to address both the reconstituted product and the drug product as supplied before reconstitution.

How many independent claims does US 8,563,033 contain?

The patent has four practical claim groups:

Claim group	Claims	Subject matter
60 mg formulation	1-8	Aqueous suspension with specified 60 mg pharmacokinetics
60 mg method	9-10	Treatment method using the claim 1 suspension
72 mg formulation	11-17	Aqueous suspension with specified 72 mg pharmacokinetics
72 mg method	18-19	Treatment method using the claim 11 suspension

Claims 1 and 11 are the principal independent formulation claims. Claims 9 and 18 are the principal independent method claims.

What are the key limitations in claim 1?

Claim 1 requires all of the following limitations:

Limitation	Requirement
Dosage form	Methylphenidate aqueous extended-release oral suspension
Release architecture	Immediate-release and sustained-release methylphenidate components
Vehicle	Water
pH	About 3.5 to about 5.0
Plasma profile	Single mean average plasma concentration peak
Duration	Therapeutically effective profile for approximately 12 hours
Dose	Equivalent to 60 mg racemic methylphenidate hydrochloride
Population	Adults
AUC	About 114 to about 180 ng·hr/mL
Cmax	About 11 to about 17 ng/mL
Tmax	About 4 to about 5.25 hours
Half-life	About 5 to about 7 hours

A competing product must satisfy the entire combination for literal infringement. Failure to meet one required limitation can defeat literal infringement of claim 1, although the doctrine of equivalents may remain relevant.

How does the pharmacokinetic language affect claim scope?

The pharmacokinetic limitations materially narrow the claims. The patent is not limited only by ingredients and dosage form. It also requires a particular in vivo performance profile.

The principal parameters are:

• AUC from administration to infinity;
• Maximum plasma concentration;
• Time to maximum concentration;
• Elimination half-life;
• A single average concentration peak;
• Therapeutic activity for approximately 12 hours.

The use of "about" creates a range of permissible variation. The claims do not define the exact numerical tolerance associated with "about." Courts would likely assess the term in view of the specification, examples, scientific measurement variability, and the ordinary meaning of pharmacokinetic testing.

The claim also uses population and dose limitations. A pharmacokinetic study conducted in children, at a materially different dose, or using a different methylphenidate salt may not directly establish infringement of the adult 60 mg limitation.

What additional limitations are added by claims 2 through 10?

Claims 2 through 10 add formulation, composition, and treatment limitations.

Claim	Added limitation
2	pH of about 4.0 to about 4.5
3	Specific d-methylphenidate AUC, Cmax, Tmax, and half-life
4	At least about 80% water by weight
5	Racemic methylphenidate or dexmethylphenidate
6	About 10-30% immediate-release and 70-90% sustained-release methylphenidate
7	Specified acidic or salt buffering agents
8	Sodium citrate and anhydrous citric acid buffer
9	Treatment method producing effective methylphenidate within 45 minutes and one average peak
10	Treatment method with pH of about 4.0 to about 4.5

Claim 6 is particularly important because it limits the release architecture to a relatively small immediate-release fraction and a substantially larger sustained-release fraction. A formulation using a materially different ratio may avoid literal infringement of claim 6 while still implicating claim 1.

Claim 8 is narrower than claim 7. It requires the specific combination of sodium citrate and anhydrous citric acid.

What are the key limitations in claim 11?

Claim 11 is directed to the 72 mg dose-equivalent embodiment. It requires:

• An aqueous suspension;
• Immediate-release and sustained-release methylphenidate components;
• Water;
• A pH of about 3.5 to about 5.0;
• A single mean plasma concentration peak;
• Approximately 12 hours of therapeutic activity;
• Administration equivalent to 72 mg racemic methylphenidate hydrochloride;
• Adult pharmacokinetics within the following ranges:

Parameter	Claimed range
AUC0-∞	About 137.2 to about 214.4 ng·hr/mL
Cmax	About 13.6 to about 21.3 ng/mL
Tmax	About 3 to about 5 hours

Claim 12 narrows claim 11 to the reported point estimates:

• AUC0-∞: 171.5 ng·hr/mL;
• Cmax: 17.0 ng/mL;
• Tmax: 3.77 hours.

Claims 13 through 19 substantially mirror claims 4 through 10, with the 72 mg formulation substituted for the 60 mg formulation.

What formulations are protected by US 8,563,033?

The strongest formulation coverage applies to an aqueous suspension that combines the following characteristics:

1. Methylphenidate is present in two release fractions.
2. At least part of the drug is immediately available.
3. The balance is sustained-release.
4. The final product is water-based.
5. The pH is acidic, generally around 4.0 to 4.5.
6. The formulation produces a single rather than multiple concentration peaks.
7. The product provides approximately 12 hours of therapeutic exposure.
8. The adult pharmacokinetics fall within the stated ranges.

The claims do not require a specific sustained-release mechanism in their independent form. They do not expressly require a particular polymer, ion-exchange resin, coating, particle size, viscosity, preservative, sweetener, flavor, or manufacturing process.

That omission expands the potential product scope, provided the accused formulation meets the claimed release and pharmacokinetic profile.

What excipients are specifically covered?

The dependent claims identify acidic buffering systems, including:

• Citric acid;
• Sodium citrate;
• Ascorbic acid;
• Acetic acid;
• Tartaric acid;
• Phosphoric acid;
• Pharmaceutically acceptable salts of those acids;
• Mixtures of the listed acids and salts.

Claim 8 specifically covers sodium citrate with anhydrous citric acid. A formulation using a different buffer may avoid claims 7 and 8 but remain within claim 1 or claim 11 if all independent-claim limitations are met.

How broad are the method-of-use claims?

Claims 9 and 18 cover administering the claimed suspension to a patient with a condition susceptible to methylphenidate treatment. The method claims require:

• Administration of the patented suspension;
• Therapeutically effective methylphenidate within 45 minutes;
• A single average plasma concentration peak.

The claims are not limited expressly to ADHD. The phrase "a condition susceptible to treatment with methylphenidate" could encompass other clinically accepted methylphenidate uses, subject to claim construction and written-description analysis.

The method claims may be difficult to enforce against a generic manufacturer if the generic label omits a patented indication or does not actively encourage use in a manner that satisfies the method limitations. For a product-specific suspension, however, the formulation claims generally present the more direct infringement risk.

When does US Patent 8,563,033 lose exclusivity?

The patent's term is tied to the relevant United States filing and continuity history. Public patent and product records associate the patent family with a March 2009 priority date and an expiration date in March 2029. The Orange Book listing should control the listed patent expiration date for Hatch-Waxman timing analysis. [1, 3]

Exclusivity item	Date or status
Earliest associated priority	March 2009
Patent grant	October 2013
Projected patent expiration	March 2029
FDA approval of Quillivant XR	September 2012
New chemical entity exclusivity	Not applicable to methylphenidate
Clinical investigation exclusivity	Expired
Orphan exclusivity	Not applicable
Biosimilar exclusivity	Not applicable

The patent term should be evaluated with any patent-term adjustment, patent-term extension, terminal disclaimer, and Orange Book correction. A patent expiration date and FDA exclusivity date are separate legal events.

What was the FDA regulatory exclusivity period?

Methylphenidate was an established active ingredient before Quillivant XR. The product therefore did not receive five-year new chemical entity exclusivity. Any three-year clinical investigation exclusivity associated with the new extended-release suspension approval has expired.

The remaining commercial barrier is primarily patent-based rather than FDA exclusivity-based.

What is the Orange Book status of Quillivant XR?

Quillivant XR is an FDA-approved methylphenidate hydrochloride extended-release oral suspension. The Orange Book is the controlling FDA source for listed patents and use codes associated with an approved drug product. [1]

The patent estate associated with Quillivant XR has included continuation-family patents directed to methylphenidate formulations and related product characteristics. US 8,563,033 is the central patent analyzed here. Continuation patents must be reviewed separately because they may contain different claim scope, expiration treatment, and listing status.

An Orange Book listing does not establish that every claim is valid or infringed. It creates the statutory framework for notice, Paragraph IV litigation, and the potential 30-month stay.

Which companies are challenging the patent?

Publicly available FDA and court records should be used to identify current ANDA applicants and Paragraph IV defendants. The information supplied does not establish a current, complete list of challengers or an active district court case involving US 8,563,033.

The likely challenge route is an ANDA certification alleging that:

• The patent is invalid;
• The patent is unenforceable;
• The proposed generic does not infringe;
• The ANDA label does not induce infringement of the method claims.

A Paragraph IV certification would require notice to the patent owner and NDA holder. If suit is filed within 45 days, FDA approval may be subject to a 30-month stay, subject to statutory exceptions and court action.

What Paragraph IV arguments are most likely against US 8,563,033?

Anticipation and obviousness

A challenger may combine earlier methylphenidate suspension disclosures with known extended-release technologies. The likely prior-art themes include:

• Immediate-release and sustained-release methylphenidate combinations;
• Aqueous oral suspensions;
• Acidic pH adjustment;
• Buffer systems;
• Extended-release polymers or coated particles;
• Once-daily methylphenidate pharmacokinetics.

The strongest invalidity argument would require prior art disclosing, or making obvious, the claimed combination of formulation structure and pharmacokinetic ranges. A reference disclosing only a sustained-release suspension without the claimed single-peak profile would be less direct.

Indefiniteness

Potential indefiniteness arguments may target:

• "About" in the pharmacokinetic ranges;
• "Single mean average plasma concentration peak";
• "Therapeutically effective plasma profile";
• "About 12 hours";
• The testing conditions used to measure the claimed pharmacokinetics.

The claims identify dose, adult subjects, and several numerical parameters, which supports definiteness. The absence of a precise boundary for "about" remains a possible litigation issue.

Written description and enablement

The claims cover a broad class of aqueous methylphenidate suspensions, while the pharmacokinetic result may depend on detailed particle engineering, release coatings, excipient selection, and manufacturing controls.

A challenger could argue that the specification does not enable the full scope without undue experimentation. The patent owner would rely on formulation examples, pharmacokinetic data, routine optimization, and the relationship between immediate-release and sustained-release fractions.

Inherency and testing disputes

A generic applicant may contend that its formulation does not meet the PK limitations. The patent owner may argue that the claimed profile is inherent in the accused formulation or that differences are within ordinary analytical and intersubject variability.

This makes comparative pharmacokinetic testing central to any infringement dispute.

How strong is the patent estate for Quillivant XR?

The estate is strongest against a generic that closely replicates the reference product's:

• Aqueous suspension format;
• Immediate-release/sustained-release architecture;
• Acidic pH;
• Once-daily 12-hour profile;
• Single concentration peak;
• Dose-normalized PK profile.

The estate is weaker against a product that uses a different release mechanism or materially changes the PK profile.

Risk factor	Assessment
Dosage-form coverage	Strong for aqueous extended-release suspensions
Ingredient coverage	Moderate; claims are methylphenidate-specific
pH coverage	Strong within the 3.5-5.0 range
Release-profile coverage	Strong if one peak and approximately 12-hour activity are demonstrated
PK-range coverage	Potentially strong but dependent on testing
Excipient coverage	Narrower, dependent on the listed buffer
Method-of-use coverage	Moderate; label and inducement issues apply
Manufacturing-process coverage	Limited in the quoted claims
Design-around potential	Meaningful through release mechanism, pH, or PK profile
Remaining term	Approximately four years as of 2025, based on the March 2029 expiration

What generic launch scenarios exist?

Scenario 1: Paragraph IV challenge

A generic applicant files an ANDA with a Paragraph IV certification. The patent owner sues within 45 days. FDA approval may be stayed for up to 30 months unless the litigation resolves earlier or the stay is otherwise removed.

This is the principal risk before patent expiration.

Scenario 2: Paragraph III certification

The applicant accepts the patent and certifies that it will not launch until patent expiration. FDA approval can proceed without a Paragraph IV dispute, but commercial launch is delayed until the listed patent expires.

Scenario 3: Non-infringing formulation

The applicant develops a suspension that does not meet one or more required limitations, such as:

• A pH outside the claimed range;
• A different release architecture;
• More than one mean plasma peak;
• A shorter or longer therapeutic profile;
• PK values outside the claimed ranges;
• No immediate-release fraction;
• No sustained-release fraction as construed by the court.

This route reduces litigation exposure but can increase development and regulatory risk.

Scenario 4: Settlement and licensed entry

The patent owner and ANDA applicant may agree to an authorized launch date, license, supply arrangement, or other settlement structure. Any settlement involving an ANDA applicant may require FTC and Department of Justice review under the Medicare Modernization Act reporting regime. No settlement terms are established by the claim text supplied.

What manufacturing and intellectual-property barriers remain?

The claims do not expressly require a particular manufacturing process. That reduces process-patent exposure under the claims quoted but does not eliminate other barriers.

A commercial generic must reproduce or demonstrate:

• Uniform drug distribution;
• Physical stability during shelf life;
• Controlled release after reconstitution;
• Dose uniformity;
• Redispersibility;
• Acceptable viscosity and palatability;
• Microbial quality;
• Consistent particle or resin performance;
• Pharmacokinetic comparability.

The practical barrier is therefore a combination of formulation engineering and FDA bioequivalence requirements. A generic could avoid literal infringement while still facing difficulties demonstrating bioequivalence to a complex extended-release suspension.

How does US 8,563,033 compare with competing methylphenidate patent estates?

Product	Dosage form	Release approach	Main patent risk
Quillivant XR	Aqueous oral suspension	Immediate-release plus sustained-release	Suspension composition and PK claims
Concerta	Extended-release tablet	Osmotic delivery system	Tablet structure, delivery system, and method claims
Ritalin LA	Modified-release capsule	Immediate and delayed-release beads	Bead architecture and release timing
Focalin XR	Modified-release capsule	Dexmethylphenidate bead system	Dexmethylphenidate release technology
Aptensio XR	Extended-release capsule	Multilayer or coated particles	Multiparticulate release system
Dyanavel XR	Extended-release oral suspension	Methylphenidate suspension technology	Separate product-specific formulation estate

US 8,563,033 is differentiated by its focus on an aqueous suspension with defined PK behavior. It does not broadly control all extended-release methylphenidate products.

What is the revenue exposure from this patent?

Quillivant XR revenue is not generally disclosed as a separate public line item by its commercial owner. The relevant exposure is concentrated in the extended-release liquid methylphenidate segment rather than the entire methylphenidate market.

The commercial impact of early generic entry would depend on:

• The number of approved ANDAs;
• Whether the generic is therapeutically substitutable at the pharmacy level;
• The availability of an authorized generic;
• Payer formulary treatment;
• The product's use in patients unable to swallow tablets;
• Price discounting;
• Pediatric demand;
• The timing of competing liquid formulations.

Because the patent is tied to a liquid dosage form, a generic suspension could exert greater direct substitution pressure than tablet or capsule competitors.

Key Takeaways

• US 8,563,033 is a formulation and pharmacokinetic patent, not a broad methylphenidate composition patent.
• Independent claims 1 and 11 cover 60 mg and 72 mg dose-equivalent aqueous suspensions.
• The essential combination is immediate-release methylphenidate, sustained-release methylphenidate, water, acidic pH, one average plasma peak, and approximately 12 hours of therapeutic activity.
• Claims 2 through 8 and 12 through 17 narrow the scope through pH, water content, methylphenidate form, release ratio, buffers, and specific PK values.
• Claims 9 and 18 cover treatment methods requiring therapeutic exposure within 45 minutes and a single average peak.
• FDA exclusivity has expired; the principal remaining barrier is patent protection.
• The patent term is associated with an expiration in March 2029, subject to the Orange Book and applicable patent-term calculations.
• A Paragraph IV ANDA challenge is the principal pre-expiration generic-entry pathway.
• The strongest infringement case would involve a generic closely reproducing Quillivant XR's formulation architecture and PK profile.
• Design-around opportunities exist through pH, release mechanism, PK profile, and immediate-release/sustained-release ratio.

FAQs About US Patent 8,563,033

Is US 8,563,033 a patent on Quillivant XR?

It is associated with the Quillivant XR extended-release methylphenidate suspension technology and claims formulation and pharmacokinetic characteristics that correspond closely to the product.

Does the patent cover all liquid methylphenidate products?

No. The claims require an aqueous extended-release suspension with immediate-release and sustained-release components, an acidic pH, and specified pharmacokinetic characteristics.

Can a generic avoid the patent by using dexmethylphenidate?

Not necessarily. Claims 5 and 14 expressly include racemic methylphenidate and dexmethylphenidate in the immediate-release and sustained-release components. The full claim limitations would still need to be evaluated.

Does a generic need to reproduce the exact Quillivant XR pH?

For literal infringement of the independent claims, the product must fall within the claimed pH range of approximately 3.5 to 5.0. Claims 2 and 10, and their 72 mg counterparts, narrow the range to approximately 4.0 to 4.5.

Is a biosimilar pathway available for Quillivant XR?

No. Quillivant XR contains chemically synthesized methylphenidate hydrochloride. A competing product would ordinarily use the ANDA pathway rather than the biosimilar pathway.

References

1. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
2. U.S. Food and Drug Administration. (2023). Quillivant XR prescribing information. FDA.
3. United States Patent and Trademark Office. (2013). U.S. Patent No. 8,563,033: Methylphenidate formulations. U.S. Department of Commerce.
4. United States Code. (2024). 21 U.S.C. § 355(j): Abbreviated applications for new drugs. Cornell Legal Information Institute.
5. United States Code. (2024). 35 U.S.C. §§ 154 and 156: Patent term and patent term extension. Cornell Legal Information Institute.

Drugs Protected by US Patent 8,563,033

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Nextwave	QUILLIVANT XR	methylphenidate hydrochloride	FOR SUSPENSION, EXTENDED RELEASE;ORAL	202100-001	Sep 27, 2012	AB	RX	Yes	Yes			Y			TREATING A PATIENT HAVING A CONDITION SUSCEPTIBLE TO TREATMENT WITH METHYLPHENIDATE, SUCH AS ADHD, BY ADMINISTERING THE FORMULATION RECITED IN CLAIMS 1 OR 2

International Family Members for US Patent 8,563,033

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2011359405
Australia	2017202955
Brazil	112013020537
Canada	2825991