United States Patent 10,864,219: Scope, Claim Architecture, and Competitive Patent Landscape for Loteprednol Etabonate Nanoparticles with Poloxamer 407 Mucus Penetration Coating
What does US 10,864,219 claim in plain technical terms?
US 10,864,219 claims methods for treating ocular inflammation using a topical suspension that contains mucus-penetrating, non-covalently coated nanoparticles with loteprednol etabonate as the core drug payload and poloxamer 407 (a PEO-PPO-PEO triblock) as the coating.
The claims are drafted to lock down:
- Drug identity and core composition (loteprednol etabonate as ≥80 wt% and often ≥90 wt% or higher)
- Coating chemistry and adsorption mode (triblock adsorbed non-covalently; poloxamer 407 specifically in dependent claims)
- Quantitative formulation constraints (1% w/v LOTE total; specific ranges for glycerin and sodium chloride; drug-to-copolymer ratio in one independent claim)
- Physical-chemical particle attributes (size range, Z-average sizing, polydispersity index)
- Mucus transport surrogate metric (relative velocity in human cervicovaginal mucus)
- Optional gamma-sterilization and impurities tolerance (limit on a specific steroidal chloromethyl ester byproduct after gamma irradiation)
The patent includes two method claim families:
- A more composition-defined architecture (Claim 1) tied to specific triblock parameters and a loteprednol:triblock weight ratio (2:1).
- A second architecture (Claims 17-39) that is narrower in one respect (explicit poloxamer 407 at 0.5% w/v) but broadens by incorporating “one or more ophthalmically acceptable carriers” and reciting different dependent limits.
What are the independent claim anchors and their scope boundaries?
Claim 1: nanoparticles with a defined PEO-PPO-PEO triblock coating architecture
Claim 1 requires all of the following in one topical suspension for ocular inflammation:
A. Treatment
- Method: treating “ocular inflammation” by administering to an eye a pharmaceutical composition.
B. Nanoparticle core
- Each coated nanoparticle has a core particle comprising loteprednol etabonate
- Loteprednol etabonate constitutes at least 80% by weight of the core particle.
C. Mucus-penetrating coating
- A “mucus penetration-enhancing coating” comprising (poly(ethylene oxide))-(poly(propylene oxide))-(poly(ethylene oxide)) triblock
- Triblock parameters:
- PO block MW ~3600 Da
- PEO blocks total ~70 wt% of the triblock
- Non-covalently adsorbed to the core particle.
D. Suspension excipients
- Glycerin: 0.5% w/v to 3% w/v
- Sodium chloride: 0.1% w/v to 1% w/v
E. Active and polymer load
- Topical suspension contains loteprednol etabonate at ~1% w/v (total).
- The ratio of total weight of loteprednol etabonate to total weight of triblock copolymer in the pharmaceutical composition is ~2:1.
F. Physical form
- Pharmaceutical composition is a topical suspension.
Claim 1 also contains numerous dependent constraints that tighten composition, particle size distribution, adsorbed layer density, and mucus transport behavior.
Claim 17: a more formulation-specified poloxamer 407 suspension
Claim 17 requires:
A. Treatment
- Treat ocular inflammation by administering a pharmaceutical composition to an eye.
B. Nanoparticle structure
- Each coated nanoparticle:
- Has a core particle comprising a single pharmaceutical agent: loteprednol etabonate
- Loteprednol etabonate ≥90 wt% of the core particle
- Has a coating on the core:
- poloxamer 407 non-covalently adsorbed to the core particle
C. Suspension formulation
- Topical suspension containing:
- ~1% w/v loteprednol etabonate total
- ~0.5% w/v poloxamer 407 total
- Includes “one or more ophthalmically acceptable carriers, additives, and/or diluents.”
D. Dependent claim hooks
Claim 17 is reinforced by dependent claims covering:
- particle size, polydispersity,
- adsorbed density,
- mucus relative velocity,
- ionic tonicity (NaCl) range,
- glycerin range,
- optional byproduct limit after gamma irradiation.
Which dependent claims narrow the technology the most? (Key quantitative fences)
Drug loading and core purity
Across the claim set:
- Claim 1 baseline: LOTE ≥80 wt% of core
- Claim 5: LOTE ≥90 wt%
- Claim 36: LOTE ≥95%
- Claim 37: LOTE ≥99%
- Claim 38 and 39 mirror the same tightening within the Claim 17 family:
- LOTE ≥95 wt% (Claim 38)
- LOTE ≥99 wt% (Claim 39)
“Substantially free of a polymeric component”
- Claim 6 and Claim 20 require the core to be substantially free of polymeric component, eliminating generic polymer-matrix nanoparticle designs that embed drug in a polymer carrier.
Nanoparticle size and distribution (DLS-based)
Two separate constraints appear:
Size range
- Claim 7 / Claim 28: ~50 nm to ~700 nm
- Claim 8 / Claim 29: size measured by dynamic light scattering
- Claim 9 / Claim 30: Z-average diameter via DLS
Polydispersity
- Claim 10 / Claim 31: PDI ≤0.5
- Claim 11 / Claim 32: PDI ≤0.4
- Claim 12 / Claim 33: PDI measured by DLS
These constraints are usually the first attack points in design-arounds: switching to larger particles, using broader distributions, or moving measurement methods away from DLS-defined Z-average.
Adsorbed coating density
- Claim 13: coated nanoparticles have triblock adsorbed at ≥0.1 molecules/nm² and <1 molecules/nm²
- Claim 26: poloxamer 407 adsorbed at ≥0.01 molecules/nm² and <1 molecules/nm²
- Claim 27: further tightens within that: ≥0.1 molecules/nm² and <1 molecules/nm²
This locks in a coating surface coverage window that distinguishes “patchy” adsorption from either too sparse or too dense layers.
Mucus transport metric
- Claim 14 / Claim 25: coated nanoparticles have relative velocity >0.5 and <6.0 in human cervicovaginal mucus
While the claim uses cervicovaginal mucus as a surrogate, it is still a quantifiable, testable transport property that can be used against formulations with different surface chemistry or charge.
Dose frequency
- Claim 3 / Claim 19: administer twice a day
This is usually non-critical for literal infringement if the formulation is used at least twice daily, but it matters for method claims tied to dosing schedules.
Excipient ranges for osmolality and viscosity
- Claim 1 / Claim 24: glycerin 0.5% w/v to 3% w/v
- Claim 1 / Claim 22-23: NaCl 0.1% w/v to 1% w/v
- Claim 21-23 explicitly define “ionic tonicity agent” as sodium chloride in dependent claims.
Gamma sterilization and byproduct cap
Two dependent claims insert manufacturing-process constraints:
- Claim 15 / Claim 34: composition further comprises ≤0.5 wt% of
17α-[(ethoxycarbonyl)oxy]-11β-hydroxy-3-oxoandrosta-4-ene-17-carboxylic acid chloromethyl ester,
relative to weight of loteprednol etabonate.
- Claim 16 / Claim 35: after gamma irradiation sterilization, the same byproduct remains ≤0.5 wt% relative to LOTE.
These are narrow but potentially high-value because a design that relies on sterilization routes that generate more of that byproduct can avoid the gamma-linked dependent claims.
How do claims 1 and 17 overlap and where do they diverge?
Overlap (shared core concept)
Both families require:
- Ocular inflammation treatment via topical suspension
- Loteprednol etabonate as the nanoparticle core
- Non-covalently adsorbed PEO-PPO-PEO triblock
- Locking the active concentration to ~1% w/v
Divergence (the legal “knobs”)
Claim 1 (more general triblock, more ratio-defined)
- Coating triblock is defined by block MW and PEO wt%
- Includes explicit ~2:1 weight ratio of LOTE to triblock copolymer.
Claim 17 (more specific to poloxamer 407 and explicit load levels)
- Coating is poloxamer 407
- Explicit suspension composition:
- ~1% w/v LOTE
- ~0.5% w/v poloxamer 407
Practical implication: A formulation that uses poloxamer 407 at ~0.5% w/v with ~1% w/v LOTE is built to land squarely in Claim 17; Claim 1 can still be implicated depending on whether the triblock MW and PEO wt% match and whether the ~2:1 ratio requirement is met.
What is the effective scope of the “mucus penetration-enhancing coating” element?
The coating is defined as:
- (PEO)-(PPO)-(PEO) triblock copolymer
- Non-covalently adsorbed
- In Claim 1, the triblock parameters are specific:
- PPO MW ~3600 Da
- PEO blocks ~70 wt% of the triblock
In Claim 4 and Claim 17 family:
- poloxamer 407 is explicitly the triblock (Claim 4 in the Claim 1 family; Claim 17 uses poloxamer 407 directly).
Scope consequence: Replacement with a different triblock with the same chemistry but different PPO MW or PEO fraction can be outside Claim 1 yet still fall into Claim 17 only if it is poloxamer 407. Since Claim 17 uses poloxamer 407 explicitly, Claim 1 is the more “technology-flexible” anchor if poloxamer 407 is replaced by a different PEO-PPO-PEO triblock matching the defined molecular parameters.
What design-arounds are directly suggested by the claim fences?
This is the actionable friction map for competitors:
1) Move outside particle size or PDI windows
- Avoid 50-700 nm and/or DLS Z-average criteria
- Avoid PDI ≤0.5 or ≤0.4
2) Change adsorption density window
- Avoid coating adsorption density targets:
- Claim 13 window: ≥0.1 <1 molecules/nm²
- Claim 26/27 window: ≥0.01 <1 (and tightened to ≥0.1 <1)
3) Break the mucus relative velocity window
- Avoid >0.5 and <6.0 in human cervicovaginal mucus
4) Alter core composition rules
- Avoid LOTE percentage requirements:
- outside ≥80, ≥90, ≥95, or ≥99 depending on dependent exposure
- Avoid “substantially free of polymeric component” if a polymer matrix is used
5) Shift active-to-polymer ratio and/or polymer load formulation constraints
- Claim 1: enforce different LOT E:triblock weight ratio away from ~2:1
- Claim 17: avoid the ~1% w/v LOTE + ~0.5% w/v poloxamer 407 pairing
6) Excipient ranges
- Adjust glycerin or NaCl outside 0.5-3% glycerin and 0.1-1% NaCl
7) Gamma sterilization byproduct tolerance
- If manufacturing relies on gamma sterilization, keep the byproduct below ≤0.5 wt% after sterilization for literal compliance. If byproduct rises above the cap, dependent claims tied to gamma irradiation can be avoided.
Where does the patent sit in a likely competitive landscape?
Given the claim scope, the patent sits at the intersection of:
- loteprednol etabonate ophthalmic anti-inflammatory delivery
- nanoparticle-based topical ocular suspension formulation
- mucus-penetrating triblock coatings using poloxamer 407
- quantitative performance metrics (DLS size/PDI, adsorption density, mucus transport)
This creates a layered infringement surface. For competitors, the high-risk area is not just “LOT E + poloxamer 407.” It is the combination with:
- non-covalent adsorption
- defined density and transport window
- specific excipient and concentration bands
- particle size and PDI as measured by DLS Z-average
- and in certain configurations, gamma sterilization byproduct control
Claims coverage map by element (literal exposure matrix)
| Claim element |
Claim 1 |
Claim 17 |
Most narrowing dependent claims |
| Ocular inflammation method |
Yes |
Yes |
Claims 2, 18 (post-surgical) |
| Topical suspension |
Yes |
Yes |
N/A |
| LOTE core |
Yes |
Yes |
Claims 5, 36-39 |
| LOTE wt% minimum |
≥80% |
≥90% |
Claims 36-39 (≥95%, ≥99%) |
| Core substantially free of polymer |
Optional |
Required |
Claim 6, Claim 20 |
| Coating type |
PEO-PPO-PEO triblock (defined) |
Poloxamer 407 |
Claim 4 (poloxamer 407) |
| Coating adsorption |
Non-covalent |
Non-covalent |
N/A |
| Triblock quantitative parameters |
PPO MW ~3600 Da; PEO ~70 wt% |
Not parameterized beyond poloxamer 407 |
Claim 1 core |
| LOTE concentration |
~1% w/v |
~1% w/v |
N/A |
| Polymer concentration |
Ratio ~2:1 |
~0.5% w/v poloxamer 407 |
Claim 1 ratio is key |
| Glycerin range |
0.5-3% w/v |
0.5-3% w/v |
Claim 24 (Claim 1 already has it) |
| NaCl range |
0.1-1% w/v |
0.1-1% w/v |
Claims 22-23 |
| Particle size window |
50-700 nm |
50-700 nm |
Claim 7/8/9; Claim 28/29/30 |
| PDI |
≤0.5 and/or ≤0.4 |
≤0.5 and/or ≤0.4 |
Claim 10-12; Claim 31-33 |
| Adsorption density |
0.1 to <1 molecules/nm² (tight) |
0.01 to <1; and ≥0.1 to <1 |
Claim 13; Claims 26-27 |
| Mucus relative velocity |
>0.5 and <6.0 |
>0.5 and <6.0 |
Claim 14; Claim 25 |
| Sterilization byproduct cap |
γ-linked cap |
γ-linked cap |
Claims 16, 35 |
Business impact: where litigation risk is highest
Risk is highest where a product:
- uses loteprednol etabonate as nanoparticle core,
- coats with poloxamer 407 non-covalently,
- targets ~1% w/v LOTE,
- uses ~0.5% w/v poloxamer 407 (Claim 17 alignment),
- and achieves DLS and mucus transport metrics within the claimed ranges.
Risk is lower only when the product:
- changes adsorption density, mucus relative velocity, or DLS-derived size/PDI, or
- moves away from the specific formulation ratios/excipient bands,
- or uses a different coating agent not matching Claim 1 parameters and not poloxamer 407 for Claim 17.
Key Takeaways
- US 10,864,219 is a combination-method patent: loteprednol etabonate-loaded nanoparticles plus a non-covalently adsorbed PEO-PPO-PEO (poloxamer 407) mucus-penetration coating in a topical ocular suspension.
- Two independent claim architectures drive coverage: Claim 1 relies on triblock molecular parameters and a ~2:1 LOTE:triblock ratio, while Claim 17 relies on poloxamer 407 at ~0.5% w/v with ~1% w/v LOTE.
- The highest-consequence narrowing features are DLS Z-average size (50-700 nm), PDI (≤0.5/≤0.4), adsorption density (molecules/nm²), and mucus relative velocity (>0.5 and <6.0).
- Gamma sterilization byproduct controls add a manufacturing-linked constraint through a ≤0.5 wt% cap for a specified steroidal chloromethyl ester after gamma irradiation.
- Competitive design-arounds must address multiple fences simultaneously, not only “drug + polymer” identity.
FAQs
1) Does the patent claim the nanoparticle composition itself or only a method of treatment?
The claims presented are method-of-treatment claims requiring administration of the specific topical suspension to an eye for ocular inflammation.
2) Is poloxamer 407 required to practice Claim 17?
Yes. Claim 17 explicitly requires poloxamer 407 non-covalently adsorbed to the loteprednol etabonate core.
3) Can Claim 1 cover coatings other than poloxamer 407?
Claim 1 defines a PEO-PPO-PEO triblock with specific block MW and PEO wt fraction and requires non-covalent adsorption. It is not limited to poloxamer 407 in Claim 1 itself, though dependent Claim 4 specifies poloxamer 407.
4) What particle characterization methods are specified for size and distribution?
The claims specify dynamic light scattering and use Z-average diameter for size, with polydispersity index measured by DLS for PDI limits.
5) What process-related limitation appears in dependent claims?
Dependent claims tie compliance to gamma irradiation sterilization and cap the level of a specific steroidal chloromethyl ester byproduct at ≤0.5 wt% relative to loteprednol etabonate after gamma irradiation.
References
[1] U.S. Patent No. 10,864,219.
