US Patent 10,441,543: Scope, Claims, and Patent Landscape for Solid Intraocular Implants with Cyclic Lipid Agents
What does US 10,441,543 claim cover in plain technical scope?
US 10,441,543 claims a solid intraocular implant formulated as a three-component matrix:
- Cyclic lipid therapeutic agent (examples explicitly limited to specific prostaglandin analogs)
- Biodegradable polymer (explicitly limited to PLA/PGA/PLGA family members)
- Low-melting cosolvent (explicitly limited to a short list that includes both fluorinated and PEG-based options)
The claims are written as a composition-of-matter and implant structure scope with multiple hard technical constraints on:
1) Component selection (agent/polymer/cosolvent lists),
2) Material compatibility (Hildebrand-like solubility parameter proximity),
3) Thermal behavior (cosolvent melt range),
4) Dose loading and release potency (20% by weight and at least 50% of maximum potency),
5) Solid-state attribute (no polymorphs of the therapeutic agent present), and
6) Device structure (monolithic implant).
This combination narrows the claim capture compared with a generic biodegradable implant for prostaglandin analogs, because infringement requires meeting every listed limitation.
Claim 1 is the core independent claim
Claim 1 requires all of the following:
A. Implant type
- “A solid intraocular implant”
B. Three formulation components
- Cyclic lipid therapeutic agent
- Polymer
- Low melting cosolvent
C. Solubility parameter constraint (compatibility window)
- “solubility parameters of the cyclic lipid therapeutic agent, the polymer and the low melting cosolvent are all within about 10 MPa^1/2 of each other”
D. Cosolvent thermal window
- low melting cosolvent melt temperature between about 50° C and 80° C
E. Therapeutic agent selection limited to explicit list
- cyclic lipid therapeutic agent is selected from:
- bimatoprost
- latanoprost
- travoprost
- unoprostone
- prostaglandin E1
- prostaglandin E2
- mixtures
F. Polymer selection limited to explicit biodegradable polymer list
- polymer is selected from:
- polylactic acid (PLA)
- polyglycolic acid (PGA)
- polylactide-co-glycolide (PLGA)
G. Low melting cosolvent selection limited to explicit list
- selected from:
- decafluorobutane
- poly(hexamethylene adipamide)
- polyethylene glycol 3350 (PEG 3350)
H. Loading
- cyclic lipid agent comprises 20% by weight of the implant
I. Release potency requirement
- potency of the cyclic lipid therapeutic agent released is at least about 50% of its maximum potency
J. Solid-state crystallinity/polymorph limitation
- “wherein no polymorphs of the therapeutic agent are present in the implant”
K. Embedded structure requirement
- The implant is solid and intended for intraocular delivery.
- Claim 6 later adds structure “monolithic.”
Dependent claims specify narrower embodiments
- Claim 2: cyclic lipid therapeutic agent is bimatoprost
- Claim 3: cyclic lipid therapeutic agent is latanoprost
- Claim 4: cyclic lipid therapeutic agent is travoprost
- Claim 5: low melting cosolvent is PEG 3350
- Claim 6: implant is monolithic
Where are the claim “safety rails” that most constrain infringement?
The claim set is constrained by several objective, measurable parameters that typically require formulation-specific evidence:
1) Solubility parameter proximity (±10 MPa^1/2 across all three components)
- This is not satisfied by “generally compatible” components.
- It requires the solubility parameters of agent + polymer + cosolvent to sit within about 10 MPa^1/2 of one another.
- In practice, this means formulating is not enough; the patent’s definitions force a matchup based on the claimed calculation framework and values.
2) Cosolvent melt range (50° C to 80° C)
- The cosolvent selection list is already narrow, but the melt range adds another gating requirement.
- If a candidate cosolvent in the list has a melt range outside the stated window (or is used in a way that changes effective melting behavior), it creates an avoidance path.
3) Agent list is explicit and excludes other prostaglandin analogs
- Even within glaucoma therapy, many prostaglandin analogs exist.
- Here, the agent must be one of the explicitly listed cyclic lipid candidates (or mixtures of them).
4) Polymer list is limited to PLA, PGA, PLGA
- Silicone matrices, polyurethanes, polycaprolactone, ethylene-vinyl acetate, and other biodegradable elastomers are outside the explicit list.
5) Cosolvent list is limited to three items
- This is one of the strongest narrowing features:
- decafluorobutane
- poly(hexamethylene adipamide)
- PEG 3350
6) Exact loading: 20% by weight
- “Comprises 20% by weight” functions as a tight quantitative limitation.
- A formulation with materially different loading risks non-infringement unless the claim construction allows tolerance around 20% (the text provided does not state tolerance).
7) Potency/release threshold: at least 50% of maximum potency
- The claim does not define the testing method.
- Still, infringement hinges on demonstrating that released agent retains potency meeting the stated threshold.
8) No polymorphs present in the implant
- This is a solid-state requirement that can be engineered around by controlling crystallization or phase state.
- It also forces analysis (e.g., XRD/DSC style testing in typical practice) tied to the claim.
9) Monolithic structure (only in Claim 6)
- If a product uses a layered or compartmental structure, Claim 6 may not apply.
- Claim 1 itself does not require monolithic structure unless the claim is interpreted to cover the whole implant, but Claim 6 is explicitly narrower.
Claim scope map by design-of-around dimensions
Below is a practical “what changes can break a limitation” map using only the limitations present in the provided claim text.
| Design dimension |
Claim 1 limitation |
Easy avoidance logic if changed |
| Agent |
Must be one of listed cyclic lipid agents |
Use a different agent not in list |
| Polymer |
Must be PLA, PGA, or PLGA |
Use a different biodegradable polymer |
| Cosolvent |
Must be one of decafluorobutane / poly(hexamethylene adipamide) / PEG 3350 |
Use another cosolvent |
| Cosolvent melt temp |
Must be 50° C to 80° C |
Choose a cosolvent in list with mismatched melting behavior or outside range (or use different thermal profile) |
| Compatibility window |
Solubility parameters of all three within ~10 MPa^1/2 |
Choose alternative polymer/cosolvent/agent set that breaks the window |
| Loading |
20% by weight cyclic lipid agent |
Use a different loading level |
| Potency |
Released potency ≥ 50% maximum |
Engineer release chemistry to reduce potency retention below threshold (in practice, harder than it sounds) |
| Polymorph state |
No polymorphs of therapeutic agent present |
Formulate to include polymorphs or mixed solid states (if acceptable for product) |
| Structure |
Monolithic only in Claim 6 |
Use non-monolithic architecture |
How broad is claim capture relative to known glaucoma and sustained-release implant practice?
Based on the claim language, the patent is not broad at the platform level. It is narrow around a specific formulation chemistry plus solid-state and release constraints:
- It does not claim “any biodegradable intraocular implant containing prostaglandin analogs.”
- It requires:
- specific polymers,
- specific cosolvents,
- a fixed 20% loading,
- a quantified compatibility metric (solubility parameter),
- a defined cosolvent melt range,
- and negative solid-state content (no polymorphs).
This posture tends to cover a specific sustained-release formulation pathway rather than covering the entire class of drug-eluting intraocular devices.
Likely claim coverage scenarios (what would fall inside vs outside)
Likely inside Claim 1 (from the provided text)
A solid intraocular implant made of:
- One of the specified prostaglandin analog agents (e.g., bimatoprost),
- embedded in PLA/PGA/PLGA,
- with one specified low-melting cosolvent (e.g., PEG 3350),
- such that the solubility parameters of all components are within ~10 MPa^1/2,
- cosolvent melt temp is 50° C to 80° C,
- drug is loaded at 20 wt%,
- released potency is ≥ 50% of maximum,
- and no polymorphs of the therapeutic agent are present.
Likely outside due to hard limitation breaks
- Different polymer class than PLA/PGA/PLGA.
- Different cosolvent than the specified list.
- Different drug (outside the explicit cyclic lipid list).
- Loading not equal to 20 wt%.
- Any formulation state where polymorphs are present.
- Missing evidence that released potency meets threshold.
US patent landscape implications (where this patent sits vs adjacent freedom-to-operate risk)
Without the application publication number, assignee, priority dates, related family members, and citation graph, the landscape can only be described at the issue-level implied by the claim text.
Landscape clustering by claim drivers
US 10,441,543 creates a risk cluster around other patents that address:
- solid sustained-release intraocular implants for prostaglandin analogs,
- biodegradable depots using PLA/PGA/PLGA,
- the use of low-melting cosolvents for processing or microstructure formation,
- solid-state control (polymorph suppression),
- and drug loading targets with preserved biological potency.
Litigation-relevant touchpoints
If a competitor product is engineered to use different polymer/cosolvent/drug families but similar processing and drug release, the most salient divergence levers are:
- cosolvent identity and melt range,
- solubility parameter compatibility,
- drug loading,
- polymorph presence,
- and potency retention.
These are the likely differentiators the patentee would emphasize for claim construction and infringement/invalidity positions.
Summary of claim set as “patent-ready” claim characteristics
- Independent claim: requires full multi-parameter match (agent + polymer + cosolvent lists; solubility parameter window; cosolvent melt range; 20 wt% loading; released potency threshold; no polymorphs).
- Dependent claims: specify (i) which agent (bimatoprost/latanoprost/travoprost), (ii) cosolvent as PEG 3350, and (iii) monolithic architecture.
Key Takeaways
- US 10,441,543 protects a specific formulation: a solid intraocular implant built from a listed cyclic lipid prostaglandin agent + PLA/PGA/PLGA + a listed low-melting cosolvent with measured compatibility (solubility parameter window) and thermal behavior (50° C to 80° C).
- The claim is tightened by quantitative and negative solid-state limitations: 20 wt% loading, ≥50% potency retention upon release, and no polymorphs of the therapeutic agent.
- Dependent claims narrow to bimatoprost/latanoprost/travoprost, PEG 3350 as cosolvent, and monolithic device structure.
- Freedom-to-operate risk is driven less by generic intraocular sustained-release concepts and more by whether a candidate product matches the exact component lists and measurable physical constraints.
FAQs
What is the key independent claim limitation that most narrows coverage?
The combination of: (i) component lists (specific drug, polymer, cosolvent) plus (ii) solubility parameter proximity within ~10 MPa^1/2, (iii) cosolvent melt temperature 50° C to 80° C, (iv) 20 wt% loading, (v) ≥50% potency retention, and (vi) no polymorphs.
Does the patent claim any prostaglandin analog beyond the listed drugs?
No. Claim 1 limits the cyclic lipid therapeutic agent to the explicit list provided (bimatoprost, latanoprost, travoprost, unoprostone, PGE1, PGE2, and mixtures).
Can a different biodegradable polymer avoid the patent?
Yes. Claim 1 requires the polymer to be selected from PLA, PGA, or PLGA. Using a different polymer class breaks the explicit polymer limitation.
Is PEG 3350 required for infringement?
Not for Claim 1. PEG 3350 is only specified in Claim 5. Claim 1 allows other listed low-melting cosolvents: decafluorobutane or poly(hexamethylene adipamide), subject to the melt range and compatibility constraints.
Is monolithic structure required for Claim 1?
No. “Monolithic” is specified in Claim 6. Claim 1 itself does not add the monolithic requirement from the text you provided.
References
[1] US Patent 10,441,543 (claims as provided in user prompt).
