Scope and patent landscape for US Patent 9,393,213 (coated particles with triblock copolymer surface-altering agents and enhanced mucus transport)
US Patent 9,393,213 claims a narrowly defined particle-coating technology for delivering solid pharmaceutical agents (including therapeutic and diagnostic payloads) where (i) the core is predominantly the solid agent by weight, (ii) the coating is a triblock copolymer with a hydrophilic–hydrophobic–hydrophilic architecture, (iii) the copolymer’s hydrophobic block anchors to the core, (iv) the hydrophilic blocks are present at the particle surface at specified mass fractions and grafting/coverage densities, and (v) the resulting coated particles exhibit a measured enhancement in mobility/transport through human cervicovaginal mucus via defined “relative velocity” and diffusivity benchmarks. Claim coverage is strongest where product form is a coated-particle composition and the mobility-through-mucus performance parameters are met.
What does US 9,393,213 claim cover: coated particle composition with triblock copolymer and mucus mobility metrics?
Core claim scope (independent claim 1). Claim 1 is a composition claim defined by both structural/material parameters and functional transport performance. It covers a “composition comprising a plurality of coated particles” with:
1) Particle core composition
- Core contains “one or more solid pharmaceutical agents or salts thereof”
- Core composition constraint: solid pharmaceutical agent(s) constitute:
- at least 95% by weight of the particle core (claim 1)
- at least 99% by weight (claim 2)
2) Coating identity and architecture
- Coating comprises a “surface-altering agent”
- The surface-altering agent is a triblock copolymer with:
- hydrophilic block–hydrophobic block–hydrophilic block
- Copolymer block mass and fraction constraints:
- hydrophobic block molecular weight ≥ 2 kDa (claim 1)
- hydrophilic blocks ≥ 15 wt% of the triblock copolymer (claim 1)
- hydrophilic blocks ≥ 30 wt% (claim 8)
- hydrophobic block MW thresholds escalated:
- ≥ 3 kDa (claims 9 and 13)
3) Anchoring and surface presentation mechanism
- Hydrophobic block associates with the surface of the core particle (claim 1)
- Hydrophilic block is present at the surface and renders the coated particle hydrophilic (claim 1)
4) Surface coverage density
- Copolymer presence density:
- ≥ 0.001 molecules/nm² on the surface (claim 1)
- ≥ 0.01 molecules/nm² (claim 7)
5) Performance in human cervicovaginal mucus
- Claim 1 requires a measured transport metric:
- coated particles have relative velocity > 0.5 in mucus
- Dependent expansions:
- relative velocity > 0.8 (claim 25)
- “mucus is human cervicovaginal mucus” (claim 26)
- additional diffusivity benchmark:
- diffusivity in human cervicovaginal mucus greater than 1/500 the diffusivity through water (over 1 second timescale) (claim 24)
Implication for scope. Even if a product matches the materials (triblock copolymer, anchors, hydrophilic fraction, density), it does not fall within claim 1 unless it also meets the mucus transport performance thresholds. Conversely, a product could meet relative velocity/diffusivity but fall outside claim scope if copolymer architecture, block MWs, or surface density are not met.
Which dependent claims narrow the triblock copolymer: hydrophilic/hydrophobic MW, wt%, and named polymers?
Hydrophilic wt% and MW
- Hydrophilic blocks ≥ 30 wt% (claim 8)
- Hydrophilic block is PEG/PEO or derivatives (claim 11)
- Hydrophilic block MW ≥ 2 kDa (claim 12)
Hydrophobic block identity and MW
- Hydrophobic block is poly(propylene oxide) (claim 13)
- Hydrophobic MW ≥ 3 kDa (claim 14)
Named triblock structures
- Explicit examples:
- poly(ethylene oxide)-polypropylene oxide)-poly(ethylene oxide) (PEO–PPO–PEO)
- poly(ethylene glycol)-poly(propylene oxide)-poly(ethylene glycol) (PEG–PPO–PEG) (claim 10)
Implication for freedom to operate. If a competitor uses a different polymer architecture (e.g., random copolymers, di-blocks, zwitterion coatings, or non-PEG hydrophiles) or uses triblock copolymers but with hydrophobic/hydrophilic MW/fraction outside the thresholds, it can reduce literal infringement risk on these dependent claims.
How broad are “surface-altering agent” attachment and density limitations?
Attachment mode
- Surface-altering agent covalently attached to core (claim 5)
- Surface-altering agent non-covalently adsorbed to core (claim 6)
These are alternative dependent limitations, not mutually exclusive in drafting sense (they read as separate claim paths). A product either way can still fit claim 1, as claim 1 already requires “surface-altering agent surrounding” and anchoring via hydrophobic block association.
Surface density
- Minimum surface coverage:
- ≥ 0.001 molecules/nm² (claim 1)
- ≥ 0.01 molecules/nm² (claim 7)
Implication. Analytical challenges (quantifying molecules/nm²) can be central in litigation and invalidity defenses. A competitor using lower surface grafting density can potentially steer outside these density limitations.
What do the composition claims cover for payload: small molecules, biologics, and “low solubility” solids?
Payload type (broad)
- Therapeutic or diagnostic agent (claim 19)
- Payload includes:
- small molecule, peptide, peptidomimetic, protein, nucleic acid, lipid (claim 20)
Solubility limitation
- Aqueous solubility ≤ 0.1 mg/mL at 25°C (claim 21)
Core state
- Crystalline cores (claim 16)
- Amorphous cores (claim 17)
- Cores are salts of the solid pharmaceutical agent (claim 18)
Implication. The claim is broad across payload classes but constrains the payload by “solid” status and (in claim 21) solubility. If a competitor formulates high-solubility drugs that do not meet the ≤0.1 mg/mL criterion, dependent claim 21 would not read, but independent claim 1 could still potentially read if other limitations match.
What particle sizes and mucus transport performance metrics are required?
Size ranges
- Core particle size: ≥ 20 nm and ≤ 1 μm (claim 22)
- Coated particle size: ≥ 20 nm and ≤ 1 μm (claim 23)
Mucus transport
- Relative velocity in mucus:
- > 0.5 (claim 1)
- > 0.8 (claim 25)
- Human cervicovaginal mucus is explicitly specified (claim 26)
- Diffusivity in mucus relative to water:
- mucus diffusivity > 1/500 of water diffusivity on a 1-second timescale (claim 24)
Implication. This is a “performance-constrained” composition. For regulatory, product development, and litigation, the measurement method used to determine “relative velocity” and “diffusivity” can become outcome-determinative.
How do formulation claims extend coverage beyond the coated particles?
Pharmaceutical composition
- Claim 27: pharmaceutical composition comprising claim 1 composition + pharmaceutically acceptable carriers
Administration modes
- Claim 28: pharmaceutical preparation suitable for:
- inhalation
- injection
- topical administration to a mucus membrane
Implication. The independent technical invention is the coated-particle composition. Claims 27–28 then extend to product presentations using standard carriers and dosage forms aimed at mucus membranes.
What is the likely effective claim boundary: material structure vs mucus performance?
Litigation boundary logic:
- Does the product use a plurality of coated particles?
- Is the core predominantly the solid pharmaceutical agent/salt (≥95% or ≥99% depending on the claim path)?
- Is the coating a triblock copolymer with the specified hydrophilic/hydrophobic architecture?
- Are block molecular weights and hydrophilic mass fraction within thresholds?
- Is hydrophobic association and hydrophilic surface presentation present?
- Does the coating meet surface density (molecules/nm²)?
- Does the coated particle meet mucus transport criteria (relative velocity and/or diffusivity benchmarks)?
Any failure on the structural elements can defeat literal infringement even if mucus performance is strong. Any failure on the mucus transport performance can defeat literal infringement even if triblock coating matches.
Patent landscape: what claims of US 9,393,213 are most likely to collide with competitor IP?
Because the claims you provided are highly specific to:
- triblock copolymer (PEO/PEG-PPO-PEO architecture),
- surface density and molecular-weight constraints, and
- enhanced motion through human cervicovaginal mucus with defined metrics,
the highest collision risk concentrates in:
- intravaginal/mucosal delivery platforms using PEG/PEO-PPO-PEG/PEO-like surfactant/stabilizer coatings,
- products designed to reduce mucus trapping and increase penetration/transport,
- coated-particle systems where the coating is engineered at defined surface coverage rather than used as a simple surfactant additive.
Lower collision risk for:
- purely solubilized formulations,
- conventional mucoadhesive gels (even if they are mucus-compatible but do not match the “relative velocity/diffusivity” thresholds and triblock anchoring),
- nanoparticles coated with non-triblock polymers (e.g., single hydrophilic polymers without hydrophobic anchoring block, or alternative architectures not matching MW/fraction limits).
Key claim elements that drive enforceability: measurement-dependent limitations
The most enforceability-sensitive features are the mucus transport metrics and surface density:
- Relative velocity thresholds (>0.5; >0.8)
- Diffusivity relative to water (>1/500 over 1 second)
- Surface coverage density (≥0.001 to ≥0.01 molecules/nm²)
These tend to be fact-intensive and can be used both by plaintiffs (to show product meets thresholds) and by defendants (to challenge testing method, lab conditions, mucus source variability, and particle characterization).
How does this patent compare against typical “muco-inert” nanoparticle strategies?
Typical mucus-transport strategies in pharma include PEGylation and mucus-penetrating coatings, but US 9,393,213 is differentiated by:
- triblock architecture requirement (hydrophilic-hydrophobic-hydrophilic),
- hydrophobic block molecular-weight anchoring constraint (≥2 kDa; ≥3 kDa in dependent claims),
- explicit hydrophilic wt% thresholds (≥15 wt% baseline; ≥30 wt% dependent),
- explicit surface coverage thresholds (molecules/nm²),
- explicit quantitative transport benchmarks in human cervicovaginal mucus.
So, even if competitors use PEG-like coatings, the infringement question pivots on whether their chemistry matches the triblock anchoring scheme and whether their products demonstrate the required transport metrics.
Commercial and competitive exposure: where this likely matters most
This patent is structurally aligned to products targeting mucus barriers, especially cervicovaginal mucus. Commercial exposure is highest for:
- coated micro/nanoparticles for intravaginal delivery of poorly soluble drugs,
- product platforms designed for mucus penetration rather than mucosal retention,
- payloads that can be formulated as predominantly solid cores (crystalline/amorphous/salt forms) with high solid loading in the core.
If a competitor’s product uses soluble drugs or drug-loaded particles where the “core is ≥95% solid agent by weight” condition is not met, exposure declines on independent claim 1.
Key Takeaways
- US 9,393,213 is a composition patent centered on triblock copolymer-coated solid drug cores engineered for quantified mobility through human cervicovaginal mucus.
- Coverage is controlled by both structure and performance: triblock architecture plus specific hydrophilic/hydrophobic MW and wt% thresholds, plus minimum surface coverage, plus relative velocity/diffusivity benchmarks.
- Highest infringement risk occurs where products use PEO/PEG-PPO-PEO/PEG triblock coatings meeting the stated MW and fraction limits and demonstrate >0.5 (or >0.8) relative velocity and/or the mucus diffusivity benchmark.
- Key litigation pressure points are the measurement-dependent mucus transport metrics and the surface density (molecules/nm²) requirements.
- Dependent claims widen payload scope (therapeutic/diagnostic; small molecules through nucleic acids and lipids) but add constraints (e.g., solubility ≤0.1 mg/mL; specific polymer chemistries; higher hydrophilic wt%).
FAQs
1. What makes US 9,393,213 “performance-limited” rather than purely formulation-limited?
Its claims require measured mucus transport outcomes (relative velocity and/or diffusivity in human cervicovaginal mucus) in addition to coating and core composition parameters.
2. Do the claims cover both covalently attached and adsorbed triblock coatings?
Yes. Dependent claims expressly cover covalent attachment and non-covalent adsorption, while independent claim 1 already requires the coated particle with hydrophobic anchoring and hydrophilic surface presentation.
3. Is the triblock copolymer limited to PEO-PPO-PEO/PEG-PPO-PEG?
The claims explicitly name these embodiments, and also constrain the hydrophilic block to PEG/PEO (and derivatives) and hydrophobic block to PPO with MW and wt% thresholds, effectively narrowing the usable polymer class.
4. What particle size window is protected?
Both core and coated particles are limited to 20 nm to 1 μm.
5. If a product has the right coating but fails the mucus velocity metric, does it still infringe?
On the text provided, it does not meet claim 1’s full limitation set, because claim 1 includes the “relative velocity > 0.5 in mucus” requirement as an element of the claimed composition.
References (APA)
- United States Patent No. 9,393,213. (n.d.). [Claims and text as provided].
