US Patent 10,406,160: Risperidone Injectable Gel Scope, Validity and Patent Landscape

US Patent 10,406,160 protects injectable risperidone base formulations using a biodegradable lactic acid-glycolic acid copolymer, commonly PLGA, dissolved or dispersed in N-methyl-2-pyrrolidone, or NMP. The patent also covers monthly subcutaneous administration and syringes containing the claimed compositions. Its claim structure is broad enough to reach the formulation architecture used by Perseris, the FDA-approved once-monthly subcutaneous risperidone product.

The principal infringement risk is concentrated in formulations containing risperidone base, PLGA-type polymer and NMP, particularly where the polymer has a predominantly lactide composition and a number-average molecular weight of approximately 5,000 to 30,000 Daltons.

What does US Patent 10,406,160 protect?

The patent claims four related subject-matter categories:

Claim category	Claims	Protected subject matter
Injectable compositions	1-14	Risperidone base suspended in a PLGA-type gel containing NMP
Monthly administration methods	15-17	Subcutaneous injection once per month
Prefilled or filled syringes	18-20	Syringes containing the claimed formulations

The independent claims are claims 1, 3 and 14.

Claim 1 is the most technically constrained independent composition claim. It requires:

Risperidone base at approximately 10 wt% to 30 wt%;
A gel containing approximately 40 wt% to 60 wt% of a lactic acid-glycolic acid copolymer;
A lactic acid:glycolic acid monomer ratio from 100:0 to 60:40;
Polymer number-average molecular weight from 5,000 to 30,000 Daltons; and
NMP.

Claim 3 is broader in several respects. It covers:

Risperidone base at approximately 1 wt% to 50 wt%;
Copolymer at approximately 5 wt% to 80 wt%; and
NMP in the gel.

Claim 14 is the broadest composition claim on its face. It requires risperidone base suspended in a gel containing:

A lactic acid-glycolic acid copolymer; and
NMP.

Unlike claim 1, claim 14 does not expressly recite concentration ranges, a specific lactide:glycolide ratio, or a molecular-weight range.

How broad is claim 14 compared with claim 1?

Claim 14 has the broadest literal composition scope, but claim 1 contains more detailed limitations that may provide stronger support against validity challenges.

Feature	Claim 1	Claim 3	Claim 14
Risperidone base	10-30 wt%	1-50 wt%	Not numerically limited
Copolymer concentration	40-60 wt%	5-80 wt%	Not numerically limited
NMP	Required	Required	Required
Lactide:glycolide ratio	100:0 to 60:40	Not in base claim	Not specified
Molecular weight	5,000-30,000 Da	Not in base claim	Not specified
Injectable composition	Required	Required	Required
Gel-only composition	Added by claim 2	Added by claim 13	Not expressly required
Monthly subcutaneous use	Claims 15	Claim 16	Claim 17

Claim 14 potentially reaches a wider range of polymer ratios, molecular weights and drug loading than claim 1. Its practical scope will depend on how the terms “copolymer of lactic acid and glycolic acid,” “gel” and “suspended” are construed in light of the specification and prosecution history.

The narrower dependent claims may remain important because they align more closely with the commercial formulation and provide fallback positions if broader claims are narrowed or invalidated.

What formulations are protected by US 10,406,160?

The patent protects formulations with the following technical profile:

Polymer phase

The polymer is a copolymer of lactic acid and glycolic acid. The claimed ratio ranges are heavily weighted toward lactic acid:

100:0;
75:25 or higher lactide content under claim 10; and
60:40 or higher lactide content under claims 1 and 9.

The claim language may encompass a 100% lactic acid polymer under the recited “100:0” range, although whether a particular material qualifies as a “copolymer” at that endpoint may raise a claim-construction issue.

Molecular weight

Claim 1 requires number-average molecular weight of 5,000 to 30,000 Daltons. Claim 11 broadens the range to 1,000 to 120,000 Daltons, while claim 12 returns to 5,000 to 30,000 Daltons.

Molecular weight is a significant design-around variable. A formulation using the same active ingredient, NMP and polymer chemistry may still fall outside claims 1, 11 and 12 if its polymer is characterized outside the claimed ranges. That strategy does not necessarily avoid claim 14, which has no express molecular-weight limitation.

Drug loading

The claim set covers a wide loading range:

1-50 wt% under claim 3;
5-40 wt% under claim 4;
5-30 wt% under claim 5; and
10-30 wt% under claim 6.

The layered ranges reduce the commercial value of a simple formulation design-around based on risperidone concentration. A competing product would need to evaluate the broader parent range before relying on a narrower concentration change.

Solvent

NMP is required throughout the independent composition claims. A formulation using another solvent, co-solvent or polymer-depot vehicle may avoid literal infringement, subject to equivalents analysis.

The “gel consists of” limitations in claims 2 and 13 are narrower than claims 1 and 3. A formulation containing additional excipients may fall outside those closed-composition claims while remaining within the corresponding open claims.

Does the patent cover Perseris?

Perseris is a once-monthly, subcutaneously administered extended-release risperidone injectable suspension approved by the FDA in 2018. The product uses the Atrigel delivery system, which is based on a biodegradable polymer and solvent system. The FDA prescribing information identifies 90 mg and 120 mg dosage strengths administered once monthly by subcutaneous injection in the abdominal region (FDA, 2018).

The claims of US 10,406,160 correspond closely to the core product architecture:

Perseris attribute	Relationship to patent claims
Risperidone base	Expressly required
Injectable depot	Expressly required
Subcutaneous administration	Claims 15-17
Once-monthly dosing	Claims 15-17
Biodegradable lactide/glycolide polymer	Expressly required
NMP-containing gel	Expressly required
Filled delivery device	Claims 18-20

The commercial product’s exact formulation percentages, polymer molecular weight and manufacturing parameters must be compared against the asserted claim limitations. Product labeling alone does not establish every formulation parameter required for claim 1. The broad language of claim 14 creates the principal product-level exposure because it does not recite the numerical limits found in claim 1.

When does US Patent 10,406,160 lose exclusivity?

US Patent 10,406,160 was granted on September 10, 2019. Its nominal patent-term endpoint is expected to fall in the mid-2030s, based on the application and priority framework associated with the patent family. The effective expiration date must account for any patent-term adjustment and any terminal disclaimer recorded in the prosecution file.

The patent is not a new chemical entity patent for risperidone. Risperidone was approved decades before the patent issued. The relevant exclusivity is therefore formulation and method-of-use protection rather than compound exclusivity.

FDA regulatory exclusivity

Perseris received FDA approval in 2018. Because the active ingredient was previously approved, the product’s regulatory exclusivity was not equivalent to a new chemical entity five-year exclusivity period. A three-year period may apply to certain new clinical investigations supporting a change in dosage form or indication, but that regulatory protection does not replace the longer patent term.

Patent expiry and FDA exclusivity are separate:

FDA exclusivity can block approval of a competing application for a defined period.
Orange Book patents can support a Paragraph IV notice and potential litigation.
Patent expiry can continue to restrict commercial launch after FDA exclusivity has ended.

What is the Orange Book status of Perseris?

Perseris is listed in FDA drug databases as an extended-release risperidone injectable product. Orange Book listings for drug-device and depot products can include formulation, method-of-use and delivery-system patents. The relevant inquiry is whether US 10,406,160 is listed against the specific approved strengths and whether the listing remains active for the relevant application.

A generic or follow-on applicant seeking approval of a substantially equivalent risperidone depot would need to assess:

The listed patents for the reference product;
Whether the applicant’s formulation practices each asserted claim;
Whether a Paragraph IV certification is available;
Whether a section viii statement can omit a patented method of use; and
Whether the FDA product-specific guidance permits the proposed formulation and route of administration.

A section viii carve-out would have limited value against composition claims 1-14. It could be more relevant to claims 15-17, which expressly recite monthly subcutaneous administration.

What Paragraph IV challenges are possible?

A Paragraph IV challenge to US 10,406,160 would likely focus on invalidity, noninfringement, or both.

Anticipation and obviousness

Potential prior-art arguments would target:

Risperidone depot formulations;
PLGA or related biodegradable polymer depots;
NMP-based in situ forming gels;
Monthly injectable antipsychotic delivery;
Risperidone suspensions in biodegradable polymers; and
Known polymer molecular-weight and lactide:glycolide combinations.

The strongest obviousness challenge would likely combine references disclosing risperidone with references disclosing PLGA/NMP injectable depot systems. The patent holder would respond that the claimed combination provides a workable monthly risperidone depot with specific suspension, release and injectability properties.

Written description and enablement

Claim 14 is materially broader than claim 1. A challenger could argue that the specification does not enable the full scope of every possible PLGA composition, molecular weight, polymer ratio and risperidone loading encompassed by the claim.

The patent holder would rely on working examples, formulation tables and the predictable nature of PLGA/NMP depot technology. The outcome would depend on the breadth of the disclosure and the amount of experimentation required across the full claim scope.

Indefiniteness

Potential claim-construction issues include:

The meaning of “gel”;
The boundary between “suspended” and dissolved risperidone;
The significance of the 100:0 lactide:glycolide endpoint;
The measurement method for number-average molecular weight; and
Whether the “gel consists of” language excludes residual processing materials or incidental components.

These issues are more relevant to enforcement than to routine FDA review.

Which companies are challenging the patent estate?

The commercial threat is more likely to arise from generic injectable manufacturers, complex generics developers and long-acting injectable specialists than from conventional oral-risperidone companies.

Potential competitors include companies with experience in:

Long-acting injectable antipsychotics;
PLGA microspheres;
In situ forming depots;
Complex injectable generics; and
505(b)(2) reformulations.

The principal commercial barrier is formulation development, not merely patent clearance. A competitor must demonstrate acceptable syringeability, suspension stability, subcutaneous tolerability, release kinetics, dose uniformity and manufacturing reproducibility.

How strong is the patent estate for Perseris?

The estate is strongest where the competing product reproduces all of the following:

Risperidone base rather than a different salt or prodrug;
A biodegradable lactide/glycolide polymer;
NMP as the solvent;
An injectable gel or in situ depot;
Monthly subcutaneous dosing; and
A prefilled syringe or equivalent filled delivery system.

Its strength is lower against:

Non-NMP solvent systems;
Microsphere products rather than in situ gels;
Intramuscular rather than subcutaneous administration;
Non-PLGA biodegradable polymers;
Different active-ingredient forms;
Polymer compositions outside the numerical ranges; and
Dosing intervals other than once monthly.

The estate has layered claim coverage, but the claims are concentrated around a single delivery platform. A technically distinct depot system could avoid much of the claim set without recreating the same formulation.

What manufacturing and IP barriers exist?

Manufacturing is a meaningful barrier to entry. The formulation must maintain a uniform suspension of risperidone base in a viscous polymer/NMP system. Relevant process controls include:

Polymer molecular-weight distribution;
Residual solvent;
Water content;
Particle-size distribution;
Mixing energy and temperature;
Fill-weight accuracy;
Syringe compatibility;
Sedimentation control; and
In vitro and in vivo release performance.

Claims 18-20 also create delivery-device exposure where a syringe is supplied with the claimed composition. A competitor could use a vial or cartridge, but that change would not avoid the composition claims.

What generic launch scenarios exist?

Launch strategy	Patent exposure	Commercial assessment
Same PLGA/NMP depot with different drug loading	High	Likely exposed to broad claim 3 or claim 14
Same formulation with different polymer molecular weight	Medium to high	May avoid narrower claims but not necessarily claim 14
Alternative solvent replacing NMP	Lower	Requires new injectability and release data
Microsphere-based risperidone injection	Lower	Different manufacturing and release platform
Intramuscular long-acting product	Lower for method claims	Composition claims remain relevant
Oral or transdermal risperidone	None under these claims	Not a substitute for monthly injectable therapy
505(b)(2) product using the same depot technology	High	Patent certifications and litigation risk remain

A generic applicant using the same formulation architecture would face a meaningful Paragraph IV litigation risk. A noninfringing launch before patent expiry would require a materially different delivery system or a successful validity challenge.

What litigation and settlement issues matter?

A patent dispute involving this patent would likely address:

Whether the accused formulation contains PLGA within the claim meaning;
Whether NMP is present in the gel phase;
Whether risperidone is suspended rather than dissolved;
How molecular weight is measured;
Whether product composition is assessed as manufactured or at administration;
Whether a filled syringe practices claims 18-20; and
Whether monthly dosing instructions induce infringement of claims 15-17.

A settlement could involve a delayed generic entry date, a license, supply arrangements, or a formulation-specific covenant not to sue. No settlement should be assumed from the existence of a Paragraph IV notice or patent litigation unless the agreement and court docket establish its terms.

How does US 10,406,160 compare with competing risperidone patents?

US 10,406,160 is a formulation and administration patent. It does not primarily protect:

The risperidone molecule;
Oral tablets;
Conventional intramuscular microspheres;
A new therapeutic indication independent of the depot formulation; or
A manufacturing process standing alone.

Its commercial value derives from the combination of formulation and dosing claims. The monthly subcutaneous method claims are especially relevant to Perseris-type products, while the composition claims can apply regardless of whether the product label emphasizes the monthly method.

Key Takeaways

US 10,406,160 claims risperidone base in a PLGA-type polymer gel containing NMP.
Claim 14 is the broadest composition claim because it omits express concentration, ratio and molecular-weight limits.
Claims 1 and 3 provide narrower, commercially targeted fallback positions.
Claims 15-17 cover once-monthly subcutaneous administration.
Claims 18-20 cover syringes containing the claimed formulations.
The patent maps closely to the formulation architecture of Perseris.
A simple change in risperidone concentration may not avoid infringement.
Replacing NMP, changing the depot technology or moving to microspheres offers stronger design-around potential.
FDA regulatory exclusivity is separate from the patent term and does not provide compound-level exclusivity for risperidone.
The main generic-entry risks are formulation similarity, Paragraph IV litigation and the difficulty of developing a bioequivalent or clinically comparable injectable depot.

FAQs

Can a risperidone product avoid US 10,406,160 by using risperidone hydrochloride?

Possibly, but the analysis depends on whether the claims require risperidone base as a chemical form. The claims supplied expressly recite risperidone base, so a product using a different active-ingredient form would require separate infringement and equivalents analysis.

Does changing the PLGA molecular weight avoid the patent?

It may avoid claims containing the 5,000-to-30,000-Dalton or 1,000-to-120,000-Dalton limitations. It may not avoid claim 14, which does not expressly recite a molecular-weight range.

Does a vial avoid the syringe claims?

A vial may avoid claims 18-20, which require a syringe. It would not avoid composition claims 1-14 if the formulation inside the vial practices those claims.

Can a monthly intramuscular risperidone product infringe the method claims?

Claims 15-17 require subcutaneous injection. An intramuscular product would not literally practice that route limitation, but composition claims may still apply if the formulation satisfies claims 1-14.

Is US 10,406,160 a patent on risperidone itself?

No. The patent claims specific injectable compositions, a monthly subcutaneous administration method and syringes containing the formulation. It does not confer broad exclusivity over risperidone in all dosage forms.

References

Food and Drug Administration. (2018). Perseris (risperidone) extended-release injectable suspension prescribing information. U.S. Department of Health and Human Services.

U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.

U.S. Patent No. 10,406,160. (2019). Injectable risperidone pharmaceutical compositions and methods of use. United States Patent and Trademark Office.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Indivior	PERSERIS KIT	risperidone	FOR SUSPENSION, EXTENDED RELEASE;SUBCUTANEOUS	210655-001	Jul 27, 2018		DISCN	Yes	No	10,406,160	⤷ Start Trial	Y			METHOD OF TREATING SCHIZOPHRENIA	⤷ Start Trial
Indivior	PERSERIS KIT	risperidone	FOR SUSPENSION, EXTENDED RELEASE;SUBCUTANEOUS	210655-002	Jul 27, 2018		DISCN	Yes	No	10,406,160	⤷ Start Trial	Y			METHOD OF TREATING SCHIZOPHRENIA	⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	056554	⤷ Start Trial
Austria	E551989	⤷ Start Trial
Australia	2006299657	⤷ Start Trial
Canada	2624088	⤷ Start Trial
China	101365423	⤷ Start Trial
Denmark	1940351	⤷ Start Trial
Denmark	2361609	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,406,160

Which drugs does patent 10,406,160 protect, and when does it expire?

Summary for Patent: 10,406,160