US Patent 9,925,268 (Risperidone PLA/PLGA Implant): Claim Scope, Material Boundaries, and U.S. Patent Landscape

What is US Patent 9,925,268 protecting for risperidone sustained-release implants?

Answer: US 9,925,268 protects an implantable sustained-release formulation in which risperidone is loaded into a biodegradable PLA-based polymer matrix (optionally with PGA) at defined polymer composition, PLA:PGA molar ratio, and drug/polymer weight fractions, where the polymer extends in vivo release duration (including a specified subcutaneous duration window).

Core claim 1 structure (what must be true)

Claim 1 requires, in combination:

Implant type: an implant comprising a therapeutic drug and a polymer.
Therapeutic drug: risperidone (single named API in your provided claim set).
Polymer identity: polymer comprises polylactic acid (PLA) and optionally polyglycolic acid (PGA).
Polymer composition (molar ratio): PLA:PGA between 50:50 and 100:0 (inclusive boundaries per your text).
Drug loading (w/w): risperidone present at about 10% to 60% (w/w).
Functional limitation: presence of the polymer extends release duration of risperidone in the subject.
Dose route/context tie-in via dependent claims: subcutaneous administration and a 1 to 6 month therapeutic level are claimed downstream.

Dependent claims that narrow the estate

From your provided dependent claims, the formulation and performance boundaries tighten in multiple axes:

Drug loading carve-outs (claims 2–13)

Risperidone weight fraction is explicitly parameterized at discrete or narrower bands:

30–60% w/w (claim 2)
60% (claim 3)
56% (claim 4)
54% (claim 5)
52% (claim 6)
50% (claim 7)
40% (claim 8)
30% (claim 9)
28% (claim 10)
20% (claim 11)
15% (claim 12)
10% (claim 13)

This creates a grid of literal infringement targets for drug loading, making “around” language central to interpretation. Even without precise prosecution history, these exact fractions function as strong anchors for enforcement.

Polymer identity and PLA:PGA ratio carve-outs (claims 14–19)

Polymer is biodegradable (claim 14)
Polymer is PLGA (claim 15) (notably, PLGA typically implies PLA/PGA copolymer, but the claim also already allows “optionally PGA,” so claim 15 can be read as a reinforcement)
Specific molar ratios:
- 75:25 (claim 16)
- 80:20 (claim 17)
- 85:15 (claim 18)
Polymer is PLA (claim 19) (maps to 100:0)

Polymer loading carve-outs (claims 20–23)

Polymer present 40–90% (w/w) (claim 20)
Further ranges for claim 20:
- 40–70% (claim 21)
- 70–90% (claim 22)
Additional fixed polymer loads for claim 1:
- 30% (claim 23)
- 35% (claim 24)
- 40% (claim 25)
- 50% (claim 26)

These dependent claims can support enforcement even where the exact risperidone loading is difficult to measure, because the polymer fraction is also pinned.

Implant properties and administration/performance (claims 27–29)

Inherent viscosity: 0.2 dl/g to 0.9 dl/g (claim 27)
Route/device: subcutaneous implant (claim 28)
Performance: extends release duration in a subject maintaining therapeutic levels for 1 to 6 months upon subcutaneous administration (claim 29)

Practical claim boundaries (literal infringement map)

Below is a compact “design space” view based strictly on your claim text.

Element	Claim 1 baseline	Dependent claim narrowing	Litigation relevance
API	Risperidone	Fixed loading % in claims 3–13	Enables targeted infringement by formulation composition
Matrix polymer	PLA with optional PGA	PLA-only (claim 19) and PLGA (claim 15)	Captures PLA-only and PLA/PGA copolymers
PLA:PGA molar ratio	50:50 to 100:0	75:25, 80:20, 85:15	Defines copolymer chemistry limits
Drug loading	~10–60% w/w	Discrete % points (10, 15, 20, 28, 30, 40, 50, 52, 54, 56, 60)	Creates multiple literal targets
Polymer loading	(implied by total)	30, 35, 40, 50% fixed; 40–90% and subranges	Adds alternate measurement basis
Implant type/route	Implant	Subcutaneous (claim 28)	Route-specific infringement can matter in enforcement
Performance	Release extended	1–6 months therapeutic levels (claim 29)	Provides functional enforcement hook

How do claim terms like “about” and viscosity limit or expand protection?

Answer: “About” appears in both drug loading and polymer fraction boundaries (via “about 10%–60%,” “about 40–90%,” and discrete “about X%” dependents). This typically broadens coverage beyond exact percentages, but in enforcement it often becomes a measurement-and-standards battle.

“About” risk points for competitors

Competitors can attempt to steer outside literal infringement by:

choosing risperidone loading just outside discrete dependent values
choosing polymer fractions that avoid fixed or ranged limits
selecting copolymer ratios outside 50:50–100:0, or avoiding the specific enumerated molar ratios if courts treat those as strong anchors
using different polymer chemistries or non-PLA/PGA matrices
using non-subcutaneous devices or demonstrating release profiles outside 1–6 months “therapeutic level” framing

Inherent viscosity gate (claim 27)

The implant’s inherent viscosity of 0.2–0.9 dl/g introduces a manufacturing/process-linked parameter. If inherent viscosity is used as a proxy for molecular weight and polymer degradation behavior, it can constrain acceptable manufacturing conditions.

What formulations does the patent likely cover beyond the literal implant?

Answer: Based on claim text alone, the patent is centered on implantable sustained-release risperidone made from a PLA or PLGA matrix (PLA with optional PGA) with high risperidone loading (10–60% w/w), designed to maintain therapeutic levels for 1–6 months in subcutaneous administration.

Likely formulation design themes implied by claim boundaries

High drug loading: 10–60% w/w suggests the matrix can hold substantial API without immediate burst release.
Matrix-driven release: the polymer is doing the extension work; claims do not recite specific coatings or multilayer diffusion barriers in the provided set.
Device-relevant claims: “subcutaneous implant” ties formulation to an implantable dosage form, not just injectable depot suspension.

If a competing product uses PLA/PLGA but changes the route, loading fraction, or PLA:PGA ratio band, claim 1 may still be asserted, while dependent claims may provide narrower “pick-off” targets.

How does US 9,925,268 compare with typical risperidone long-acting depot IP (injectable vs implant)?

Answer: The claim language you provided is specific to an implant and subcutaneous administration. That distinguishes it from many common long-acting risperidone depot strategies that are built around injectables (typically microspheres or polymeric suspensions).

Key differentiator in scope

Your patent: implant and subcutaneous implant with 1–6 month therapeutic level.
Typical alternative depots: may be intramuscular injections, injectable microsphere suspensions, or polymer-drug conjugate approaches.

A competitor can reduce exposure by shifting dose form class and route (if they can avoid literal “implant/subcutaneous implant” characterization and performance elements).

Which companies are most at risk for infringing US 9,925,268?

Answer: No company-specific infringement risk assessment can be produced from the information provided. The claim set alone does not establish the identities of:

the assignees of US 9,925,268
commercial products that match the claim’s PLA/PLGA ratio, drug loading, viscosity, and 1–6 month therapeutic level in subcutaneous implants

Without those identifiers and without a corresponding Orange Book/patent listing set, a litigation-risk leaderboard cannot be constructed.

When does US 9,925,268 expire and how does that affect generic or biosimilar entry risk?

Answer: No expiration timeline can be computed from your inputs. Patent term depends on:

filing date (and any CIP/divisional history)
USPTO publication and issuance dates
maintenance status
possible adjustment/terminal disclaimer
whether the patent is a continuation with different term rules

Without the patent’s bibliographic record, an exclusivity map for “generic entry risks” cannot be generated accurately.

What does the claim set imply about Paragraph IV challenges or Orange Book status?

Answer: The patent landscape cannot be tied to Paragraph IV or Orange Book status from the claim text alone. Those determinations require:

Orange Book listings for the drug
whether US 9,925,268 is listed for the relevant NDA/BLA and strength/dosage form
whether any ANDA notice filings (Paragraph IV) reference this patent

No Orange Book status or certification link can be produced from the provided material.

How strong is the patent estate around composition vs. performance?

Answer: The claim set is composition-heavy and also includes a performance functional boundary.

Composition strength indicators

Specific polymer system: PLA with optional PGA, plus explicit PLA-only and specific molar ratios.
Specific high-range drug loadings with exact discrete values in dependents.
Polymer fraction constraints (fixed and ranges).
Inherent viscosity window.

These are enforcement-friendly because they can be evaluated through formulation analysis and polymer characterization.

Performance strength indicators

Claim 29 recites 1 to 6 months maintenance of therapeutic levels after subcutaneous administration.
This is still partly measurement-based, but it reduces the chance that an “identical polymer + different release profile” design is automatically outside the claim.

How would a competitor design around the claims?

Answer: Based on the boundaries in your claim text, the main design-around levers are:

Avoid PLA/PLGA (PLA with optional PGA): switch to different polymer chemistry.
Alter PLA:PGA molar ratio: target compositions outside 50:50 to 100:0 and avoid the specific enumerated ratios (if treated as particularly important).
Change risperidone loading: move outside ~10–60% w/w and outside the discrete “about X%” values in dependent claims.
Change polymer loading: alter polymer fraction outside fixed dependent values and outside the 40–90% ranges.
Change inherent viscosity: manufacture to yield inherent viscosity outside 0.2–0.9 dl/g.
Change route/dosage form characterization: avoid “subcutaneous implant,” for example by using a different route or dosage form category that does not map to “implant.”
Change release performance window: avoid maintaining therapeutic levels for 1–6 months in the claimed subcutaneous context (this can be hard if marketed as long-acting for that duration).

What patent landscape search results should be expected around this claim theme?

Answer: No landscape can be populated without the patent bibliographic record (assignee, priority family, earlier continuations/divisionals) and without cited references. However, the claim’s structure typically correlates with families covering:

risperidone-polymer combinations
PLA/PLGA composition ratios and molecular weight/viscosity ranges
implant or depot device embodiments
release-duration testing and performance endpoints
manufacturing methods that tune polymer degradation and diffusion

Key Takeaways

US 9,925,268’s claim 1 is a high-specificity formulation claim: risperidone plus a PLA (optionally PGA) polymer matrix, with PLA:PGA molar ratio 50:50 to 100:0, risperidone loading ~10–60% w/w, and a release-extending functional requirement.
Dependent claims create multiple composition “pick-off” points for infringement by pinning risperidone loading at discrete “about X%” values and by defining polymer loadings and PLA:PGA sub-ratios.
The estate also includes route and performance locks: subcutaneous implant and 1–6 months therapeutic-level maintenance.
A credible design-around would likely require moving off one or more of: polymer chemistry (PLA/PLGA), PLA:PGA ratio, drug and polymer loading, inherent viscosity window, and subcutaneous 1–6 month performance.

FAQs

Does US 9,925,268 require a specific implant geometry or only “implant” as a dosage form?
Your claim text states “an implant comprising…,” without geometry details, suggesting the scope is tied to dosage form class and functional release rather than a specific shape, based on the provided language.
If a formulation uses PLA only (no PGA), does it still fall within the claim scope?
Yes. Claim 1 allows optional PGA with PLA:PGA up to 100:0, and dependent claim 19 explicitly covers polymer as PLA.
Can a competitor avoid infringement by adjusting risperidone content slightly?
Adjustments can reduce literal risk given the discrete dependent “about X%” loadings, but claim 1’s broader “about 10%–60%” band still needs to be avoided.
How does the 1–6 month therapeutic level requirement change infringement analysis?
It adds a performance element tied to subcutaneous administration. A product with similar composition but different release profile may contest that limitation.
Is the inherent viscosity range likely to be a major enforcement lever?
Yes. Claim 27 ties scope to implant inherent viscosity of 0.2–0.9 dl/g, linking infringement to measurable polymer property controlled by manufacturing and molecular weight selection.

References

No references can be listed because no patent bibliographic record, assignee/priority data, or external sources were provided in the prompt, and no citations can be generated from the claim text alone.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2005206143	⤷ Start Trial
Australia	2006269927	⤷ Start Trial
Canada	2553254	⤷ Start Trial
Canada	2614601	⤷ Start Trial
China	101287423	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,925,268

Summary for Patent: 9,925,268