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Patent landscape, scope, and claims: |
Scope and patent landscape for US Patent 8,168,620 (azelastine + fluticasone nasal formulations)
US Patent 8,168,620 claims a nasal, azelastine (or salt) plus fluticasone ester combination formulation in specific dosage-form and compositional ranges, including aqueous suspensions and defined excipient classes. The estate is claim-clustered around (i) formulation composition (azelastine + fluticasone ester), (ii) nasal delivery modality (drops/spray), and (iii) particle size and formulation parameters (sub-10 µm particles, pH ranges, and wt/wt ranges of actives), with narrower dependent claim layers on salts (azelastine HCl), fluticasone ester choice (propionate vs valerate), additive/excipient embodiments, and process-by-mixing. The practical enforcement surface is formulation infringement (and process infringement where applicable), not method-of-treatment per se, though some claims tether use to anti-histamine and steroid indications.
What claims are protecting (high-level)
Core protected subject matter
- A pharmaceutical formulation for nasal administration containing:
- azelastine (or azelastine hydrochloride), and
- a pharmaceutically acceptable ester of fluticasone (specifically fluticasone propionate or fluticasone valerate).
- Claims extend to aqueous suspensions, with particle size <10 µm, and defined wt/wt ranges for each active.
- Claims extend to nasal drops and/or nasal spray (dependent claim scaffolding).
- Claims incorporate a typical nasal suspension excipient framework: buffers, preservatives, suspending/thickening agents, surfactants, isotonic agents, with detailed dependent embodiments.
Claim architecture
- Claim 1 is the broadest formulation anchor.
- Claims 2–4 and 5–6 specify salt form, fluticasone ester selection, particle size, and numeric concentration ranges.
- Claims 7–12 expand into excipient classes and define an aqueous suspension.
- Claims 13–15 establish delivery modality (drops vs spray).
- Claims 16–20 include a use/indication tether (treatment where anti-histamine and/or steroid administration is indicated) and a more specific azelastine HCl plus propionate/valerate pairing.
- Claims 21 is a preparation process by admixing carrier/excipient with actives.
- Claims 24–25 are additional formulation claims emphasizing the nasal spray modality and excipient carrier presence.
- Claims 26–30 narrow to additional numeric embodiments and nasal spray.
- Claims 31–44 harden specific ester/salt combinations and specific excipient embodiments (edetate disodium, glycerine, thickening system microcrystalline cellulose + sodium carboxymethyl cellulose, polysorbate 80, benzalkonium chloride, phenyl ethyl alcohol, purified water).
- Claims 45–46 define pH ranges (3–7; 4.5–6.5).
- Claims 47–48 define further numeric endpoints for wt/wt actives in aqueous suspensions.
What is the claim scope of US 8,168,620 for azelastine/fluticasone nasal formulations?
Immediate answer: The claim scope covers nasal dosage forms (drops/spray) comprising azelastine (salt form optional in broad claims; HCl in dependents) plus fluticasone ester (propionate and/or valerate in dependents), in aqueous suspension embodiments with sub-10 µm particle size and defined wt/wt ranges, optionally with a standard excipient suite and defined pH.
Claim 1 (the anchor): what is the maximum “design space”?
Claim 1 requires:
- Azelastine or pharmaceutically acceptable salt
- A pharmaceutically acceptable ester of fluticasone
- Dosage form suitable for nasal administration
Claim 1 does not, by itself, require:
- aqueous suspension (that appears in dependent claim 12),
- particle size limit (<10 µm) (dependent claim 4),
- wt/wt concentration ranges (dependent claim 5 and claim 6),
- specific excipient lists (dependent claims 7–12, 42+),
- pH ranges (dependent claims 45–46),
- delivery modality (drops vs spray) (dependent claims 13–15),
- specific salt/ester selection (dependent claims 2–3).
Enforcement implication: A product that differs on aqueous/suspension details may still land within Claim 1 if it is “in a dosage form suitable for nasal administration” and contains azelastine + fluticasone ester.
Dependent claim clusters: how the scope tightens
Key narrowing layers:
- Salt and ester specificity
- Claim 2: azelastine hydrochloride
- Claim 3: fluticasone propionate or fluticasone valerate
- Claims 22–23: explicit fluticasone propionate vs valerate options
- Claims 31–34: paired embodiments with azelastine HCl + propionate/valerate
- Claims 35–37: azelastine HCl embodiments in multiple dependent contexts
- Particle size
- Claim 4: particle size < 10 µm
- Numeric concentration ranges (wt/wt)
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Claim 5: azelastine (or salt) 0.0005% to 2%; fluticasone ester 0.0357% to 1.5%
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Claim 6: subset: azelastine 0.001% to 1%; fluticasone ester 0.0357% to 1.5%
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Claims 26–27: explicit azelastine HCl = 0.1%; fluticasone propionate/valerate 0.0357% to 1.5%
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Claims 47–48: explicit azelastine HCl 0.001% to 1% and fluticasone propionate 0.0357% to 1.5%, as aqueous nasal suspensions
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Claim 48: azelastine HCl fixed at 1%, fluticasone propionate 0.0357% to 1.5%
- Excipient classes and embodiment lists
- Claim 7: at least one additive selected from buffer, preservative, suspending agent, thickening agent, surfactant, isotonic agent, or combinations
- Claim 8: surfactant comprises polysorbate and/or poloxamer
- Claim 9: isotonic agent includes sodium chloride, sucrose, glucose, glycerine, sorbitol, 1,2-propylene glycol
- Claim 10: preservative from a long enumerated set including edetic acid/salts, lower alkyl p-hydroxybenzoates, chlorhexidine, phenyl mercury borate, benzoic acid/salt, quaternary ammonium, sorbic acid/salt
- Claim 11: suspending/thickening agents from cellulose derivatives, gelatin, PVP, tragacanth, alginic acid, PVA, polyacrylic acid, pectin, combinations
- Claims 42–44: detailed “specific formulation” embodiment listing: edetate disodium, glycerine, thickening agent of microcrystalline cellulose + sodium carboxymethyl cellulose, polysorbate 80, benzalkonium chloride, phenyl ethyl alcohol, purified water
- Dosage form modality
- Claim 13: nasal drops
- Claim 15: nasal spray
- Claim 14: nasal drops
- Claim 28–30: nasal spray embodiments in multiple narrow contexts
- Claims 24–25: nasal spray formulation emphasized
- pH
- Claim 45: pH 3 to 7
- Claim 46: pH 4.5 to 6.5
- Use/indication tether
- Claim 16: used in treatment where anti-histamine and/or steroid administration is indicated
- Claims 17–20: same tether plus specific salt/ester selections
Process claim: admixing for preparation
Claim 21 protects a preparation process:
- admixing a carrier/excipient with azelastine (or salt) and fluticasone ester.
Enforcement implication: This can capture manufacturing methods even if a generic supplier argues non-literal formulation differences, depending on what is “admixed” and whether “process infringement” attaches under the applicable forum rules.
Which products or design-arounds are likely outside US 8,168,620?
Immediate answer: Likely outside only if they avoid at least one required claim element at the independent/dependent level: omit one active (azelastine or fluticasone ester), use non-nasal delivery, use a fluticasone entity not covered as “an ester,” avoid aqueous suspension where required by asserted dependent claims, avoid sub-10 µm particle size where that dependent claim is asserted, avoid the wt/wt ranges where those dependent claims are asserted, and/or avoid specific excipient classes or specific enumerated embodiments where narrower dependent claims are asserted.
The easiest “outside” levers
- No fluticasone ester (replace with a non-ester fluticasone form would not literally satisfy “ester of fluticasone” language).
- Non-nasal dosage form (oral inhalation, topical skin, ocular, etc.).
- Not a formulation “suitable for nasal administration.” Practically, most intranasal sprays/drops meet this.
Design-around through numeric ranges and particle size
- If a challenger faces dependent claims 4 and 5–6/26–27/47–48, shifting:
- particle size to ≥10 µm, and/or
- wt/wt actives to outside:
- azelastine 0.0005%–2% or 0.001%–1% depending on the asserted dependent claim,
- fluticasone ester 0.0357%–1.5% (most claim sets keep this same upper band),
can reduce literal coverage, though Claim 1 may still remain if those dependent restrictions are not part of the asserted set.
Excipient-based avoidance
Claims 7–11 are class-based; Claim 42–44 are detailed embodiment-based. Avoiding those exact excipient systems may defeat those dependents but typically not Claim 1 unless excipients are made essential by the asserted claims.
How would courts construe “fluticasone ester” and “particle size <10 µm” in infringement?
Immediate answer: Literal infringement turns on whether the product contains a compound that qualifies as a “pharmaceutically acceptable ester of fluticasone” and whether the formulation’s measured particle size meets the <10 µm limitation in the asserted dependent claim set.
“Fluticasone ester” coverage in this patent record
From the claim text provided, fluticasone propionate and fluticasone valerate are explicitly covered (claims 3, 22, 23, 24, 27, 31, 32, 33, 34, 47, 48). That creates a strong anchor for these two esters.
“Particle size <10 µm”
Dependent claim 4 imposes a measurement limitation. In enforcement, the key is how the patentee and accused infringer characterize the formulation’s particle size distribution and the test method used. Regardless of method disputes, the numerical gate is clear: if the measured particle size distribution is reliably above 10 µm, that dependent claim’s literal coverage weakens.
What is the US patent estate strategy implied by these claims (formulation + process + modality + excipients)?
Immediate answer: The claim set is built to protect the formulation itself (composition and concentration ranges), its nasal delivery form (spray/drops), the suspension microstructure (particle size and aqueous suspension), and the manufacturing method by admixing actives with standard carriers/excipients. The additional dependent “specific embodiment” claims on excipient packages and pH create backup positions for infringement where a generic modifies concentrations or uses substitutions outside the broad excipient classes.
Backup positions created by dependent claims
- If an accused product tries to move within broad azelastine/fluticasone presence but changes excipients, Claim 7–11 still cover many substitutions at a class level; Claim 42–44 are the narrower “specific package” safety net.
- If it changes actives slightly, concentration range dependents (5–6, 26–27, 47–48) create multiple numerical footholds.
- If it uses a different nasal modality, dependent claims still cover both drops and spray through separate claim scaffolding.
What does the patent text suggest about potential Paragraph IV / generic entry risk?
Immediate answer: If a generic seeks intranasal azelastine + fluticasone ester combination coverage, it faces direct formulation infringement risk across:
- Claim 1 (combination in nasal dosage form),
- dependent concentration ranges (claims 5–6, 26–27, 47–48),
- suspension/paticle size limitations (claims 4 and 12),
- and formulation parameter dependents (pH 45–46 and excipient packages 7–11 and 42–44).
Where risk concentrates
- The more the generic mirrors the likely market formulation design (intranasal spray, aqueous suspension, sub-10 µm particles, wt/wt actives in the enumerated ranges), the more it aligns with multiple dependent claims and increases litigation leverage for a patentee.
What are the most commercially relevant “claim targets” to map onto product development?
Immediate answer: Particle size, active concentration ranges, pH window, and excipient system are the four highest-signal technical mapping items because they are repeatedly asserted through dependent claim limitations that are common in formulation development and quality specifications.
Claim-to-spec mapping table (technical to legal)
| Product spec / development knob |
Claim(s) tied to it |
What to verify in accused product |
| Nasal modality (spray vs drops) |
Claims 13–15, 24–30 |
Does the product meet the modality invoked by the asserted claims |
| Aqueous suspension requirement |
Claim 12; Claims 47–48 (explicit) |
Is the formulation an aqueous suspension for those dependents |
| Sub-10 µm particle size |
Claim 4 |
Particle size distribution and test method matching the claim limitation |
| Azelastine salt form |
Claims 2, 26–27, 31–37, 47–48 |
Is azelastine used as HCl where dependent claims require it |
| Fluticasone ester identity |
Claims 3, 22–23, 24, 27, 31–34, 47–48 |
Propionate vs valerate mapping |
| wt/wt active ranges |
Claims 5–6, 26–27, 47–48 |
Concentration targets in the claim bands |
| pH window |
Claims 45–46 |
Measured formulation pH within asserted dependents |
| Surfactant/isotonic/preservative/thickener classes |
Claims 7–11 |
Class membership and whether substitutions defeat literal coverage |
| Specific excipient embodiment |
Claims 42–44 |
Presence of the listed excipient package at least as required by those claims |
How strong is the patent’s enforceability profile based on claim breadth?
Immediate answer: The patent has a layered breadth profile: Claim 1 is broad on actives and nasal suitability, while dependent claims add high-specificity constraints. This structure often strengthens enforcement when accused products closely mirror the claimed formulation, while leaving room for design-around where the accused product can reliably move outside numeric and microstructural limitations.
Breadth vs specificity summary
- Broad anchor: Claim 1 (azerlastine + fluticasone ester, nasal dosage form).
- High-probability overlaps in real products: aqueous suspension, intranasal spray, typical excipient classes, pH windows, and wt/wt actives.
- Litigation battlegrounds: particle size definition, concentration measurement, and excipient system equivalence at the dependent-claim level.
What patent litigation and FDA status are implicated by US 8,168,620?
No complete and accurate landscape can be produced from the information provided. This requires bibliographic data (assignees, priority date, publication number, prosecution history), Orange Book listings (NDA linkage), and any court dockets involving US 8,168,620. Those records are not present in the input, so they cannot be reliably stated.
Key takeaways
- US 8,168,620 is a formulation-focused intranasal combination patent: azelastine (or salt) plus a fluticasone ester, in dosage forms suitable for nasal administration.
- The claim set is layered: a broad Claim 1 is supported by dependent limitations on azelastine HCl, fluticasone propionate/valerate, aqueous suspension, particle size <10 µm, wt/wt concentration ranges, pH (3–7; 4.5–6.5), and excipient classes and specific excipient packages.
- The highest-risk technical parameters for a potential entrant are particle size, active wt/wt bands, pH, and intranasal spray vs drops modality, with excipient system composition adding additional dependent-claim leverage.
- The process claim (Claim 21) extends infringement risk to preparation by admixing carriers/excipients with the actives.
FAQs
1) Does US 8,168,620 require fluticasone propionate specifically, or does it cover fluticasone valerate too?
The broad language covers “an ester of fluticasone,” and dependent claims expressly cover fluticasone propionate and fluticasone valerate.
2) What is the particle size limit in the independent claim set?
The <10 µm limit appears as a dependent claim (Claim 4), not in Claim 1 as provided.
3) What wt/wt active concentration ranges are claimed for azelastine and fluticasone ester?
Claim 5: azelastine (or salt) 0.0005%–2% and fluticasone ester 0.0357%–1.5%. Claim 6 narrows azelastine to 0.001%–1% with the fluticasone ester range unchanged. Claims 26–27 and 47–48 add further azelastine HCl specific endpoints.
4) Are pH limits part of the claimed scope?
Yes. Dependent claims set pH at 3–7 and 4.5–6.5.
5) Does the patent cover preparation (manufacturing) steps or only the end formulation?
Yes. Claim 21 covers a process of preparing the claimed formulation by admixing a pharmaceutically acceptable carrier/excipient with azelastine (or its salt) and fluticasone ester.
References
- User-provided claim text for US Patent 8,168,620 (claims 1–48).
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