Patent Estate Analysis for US Patent 8,071,073: Claims, Scope, and US Landscape for Azelastine Nasal Spray/Liquid Rhinitis Formulations
Executive summary. US Patent 8,071,073 is directed to liquid intranasal azelastine hydrochloride formulations for allergic rhinitis and non-allergic vasomotor rhinitis, with specific attention to sweetener/tonicity system selection (sucralose or “sucratose,” sorbitol 70, citrate, preservatives, viscosity agent) and intranasal delivery (nasal spray/drops; bottle + metered multi-dose pump). The independent claim set appears composition-focused (specific excipient package and concentration targets), with dependent claims narrowing to delivery hardware and per-spray volume targets. The practical infringement and design-around risk is driven by whether a challenger matches (i) the azelastine concentration, (ii) the sucralose/sucratose + sorbitol system, (iii) the preservative window (benzalkonium chloride NF), and (iv) the osmolality range if asserted through claims 24–27.
What is US Patent 8,071,073 and what does it claim about azelastine nasal spray formulations?
US 8,071,073 claims liquid pharmaceutical compositions intended for treating allergic rhinitis or non-allergic vasomotor rhinitis. The claims are structured around:
- Core composition claims (Claims 1–3)
- Delivery system limitations (Claims 4–12)
- Nasal spray/drop and per-spray volume limitations (Claims 13–21)
- Additional excipient reinstatement / range-dependent excipient coverage (Claims 22–23)
- Osmolality-defined sorbitol parameterization (Claims 24–27)
- Fixed sucralose concentration (Claim 28)
What counts as “the invention” in claim scope?
- Active drug: azelastine hydrochloride at ~0.100% (Claim 1) or 0.1%–0.15% (Claim 2) or 0.150% (Claim 3).
- Sweetener: sucralose at 0.150% (Claim 1) or 0.1%–0.15% (Claim 2).
- Tonicity/osmolality driver: sorbitol 70% at 6.4% (Claim 1) or 0.1%–10% (Claim 2) with osmolality constraints (Claims 24–27).
- Viscosity agent: hypromellose at 0.100% (Claim 1) or 0.1%–0.15% coverage via Claim 3 ranges plus reinstatement in Claim 22.
- Chelator/buffer component: disodium edetate (0.05% in Claim 1; ranges in Claim 3/22) and sodium citrate dihydrate (0.068% in Claim 1; fixed in Claim 22/23).
- Preservative: benzalkonium chloride 50% solution, NF at 0.025% in Claim 1 and 0.001%–0.5% in Claim 3/23.
- Delivery format: intranasal nasal spray or nasal drops (Claims 1–3; narrowed to spray in Claims 13–15).
- Hardware (metered dosing): bottle + pump + metered multi-dose pump (Claims 5–6 and corresponding dependent chain 8–12).
- Dose volume: ~0.07–0.15 mL per spray (Claims 16–21) with a specific ~0.14 mL per spray embodiment (Claims 17, 19, 21).
How broad are the independent claims 1–3 for azelastine, sucralose, sorbitol, preservatives, and excipient package?
Claim 1: fixed “single-point” composition + nasal spray/drops
Claim 1 is narrower than Claim 2/3 because it uses fixed concentrations:
- Azelastine HCl: ~0.100% (w/v)
- Hypromellose: ~0.100%
- Disodium edetate: ~0.05%
- Benzalkonium chloride 50% solution, NF: ~0.025%
- Sucralose: ~0.150%
- Sorbitol 70%: ~6.4%
- Sodium citrate dihydrate: ~0.068%
- QS water to volume
- Form: nasal spray or nasal drops
Infringement implication: A composition that deviates meaningfully in any of these fixed values is less likely to meet Claim 1 literally. Claim 1 still matters because it sets a “center of gravity” for the patent family and constrains interpretation of what the patentee treated as a working formulation.
Claim 2: concentration ranges for azelastine and sucralose plus broad sorbitol window
Claim 2 expands scope with ranges:
- Azelastine HCl: 0.1% to 0.15%
- Sucratose/sucralose: 0.1% to 0.15%
- Sorbitol 70%: 0.1% to 10%
- Form: nasal spray or nasal drops
This claim is comparatively broad on azelastine and tonicity system selection. It omits some fixed excipients from the independent text (the claim text you provided does not repeat hypromellose/disodium edetate/citrate/benzalkonium here), which can affect whether they are required by the claim as written.
Infringement implication: If a challenger matches azelastine + sucratose/sucralose + sorbitol within these ranges and the remaining excipient system is argued as inherent/optional, Claim 2 can become the main assertion target. If a court construes Claim 2 as requiring only those three ingredients plus an unspecified remainder system, the scope is substantially wider than Claim 1.
Claim 3: fixed hypromellose/edetate/citrate with broad benzalkonium and wide sorbitol
Claim 3 is a hybrid:
- Azelastine HCl: 0.150%
- Hypromellose: 0.100%
- Disodium edetate: 0.05%
- Benzalkonium chloride 50% solution, NF: 0.001% to 0.5%
- Sucralose: 0.150%
- Sorbitol 70%: 0.1% to 10%
- Sodium citrate dihydrate: 0.068%
- Form: nasal spray or nasal drops
Infringement implication: Claim 3 is broad where it matters for challenge products that use different preservative levels. It is narrower on azelastine and sucralose because those are fixed at 0.150%.
Which dependent claims narrow to bottle + metered multi-dose pump and what is the practical design-around?
Intranasal delivery system limitations (Claims 4–12)
The dependent chain adds equipment constraints:
- Claim 4: composition of Claim 1 contained within an intranasal delivery system
- Claim 5: delivery system comprises bottle and a pump
- Claim 6: pump is a metered multi-dose pump
- Claims 7–12: parallel delivery-system limitations applied to compositions of Claims 2 and 3
How to read this for infringement: If an accused product is packaged in a non-metered device (or a device that a court does not classify as “metered multi-dose pump”), then the delivery-system dependent claims can fail while composition claims (1–3 and range-related dependent composition claims) might still be asserted depending on claim construction.
Design-around leverage:
- Non-metered devices (single-dose, sachet-delivered, unit-dose sprayers with non-multi-dose mechanics) can target the delivery dependent claims.
- Device differences matter most when the patentee’s asserted theory relies on Claims 4–12 rather than the pure formulation claims.
What is the spray volume limitation and how does it affect claim strength for product engineering?
Nasal spray volume per actuation (Claims 13–21)
The claims step down from “nasal spray” to specific dose volume windows:
- Claim 13–15: composition of Claims 1–3 in the form of a nasal spray
- Claim 16 / 18 / 20: spray formulated to deliver ~0.07 mL to ~0.15 mL per spray
- Claim 17 / 19 / 21: spray formulated to deliver ~0.14 mL per spray (which is within the window)
Engineering consequence: If a marketed product’s metering actuator yields a volume outside 0.07–0.15 mL, those dependent claims become harder to assert. If it is inside the window, the volume limitation is not a design-around path.
What excipient system constraints are explicitly required in Claims 22–23?
Additional excipient reinstatement (Claims 22–23)
Implication for scope: These claims widen the permitted viscosity/chelating and preservative ranges when combined with the Claim 2 baseline. Claim 23 keeps citrate fixed at 0.068%, which can be a key differentiator.
How critical is the osmolality range and what does it do to sorbitol design?
Osmolality-defined sorbitol parameterization (Claims 24–27)
The claims tie sorbitol to a target osmolality:
- Claim 24: sorbitol concentration sufficient for 220–350 mOsmol/kg
- Claim 25: same parameterization for Claim 3 composition
- Claim 26: narrower 250–320 mOsmol/kg
- Claim 27: same narrower range for Claim 3 chain
Infringement effect:
These claims are not purely about sorbitol percentage. They are functional and depend on the measured osmolality. A challenger can have a sorbitol percentage inside 0.1–10% but still land outside 220–350 mOsmol/kg if other excipients shift the osmolality.
Design-around route:
- Adjusting sorbitol (or other osmotically active excipients) to push osmolality outside the recited window is a direct strategy against Claims 24–27.
- If an accused product lands within the window, the range becomes hard to evade unless the court excludes reliance on the functional parameter for infringement.
What does Claim 28 add about sucralose fixed concentration?
- Claim 28: composition comprises sucralose at 0.15% (w/v)
This is a relatively straightforward narrowing: even if azelastine is in range and sorbitol is correct, missing the exact 0.15% sucralose concentration can avoid this dependent claim.
Claim scope map by accused product attribute (what is most likely to be litigated?)
| Product attribute |
Claims that likely track it |
What matters for infringement |
| Azelastine concentration |
1 (0.100%), 2 (0.1–0.15), 3 (0.150%) |
Match the exact value or the range; Claim 1 and Claim 3 create tighter “centers” |
| Sucralose/sucratose |
1 (0.150%), 2 (0.1–0.15), 3 (0.150%), 28 (0.15) |
Exact concentration supports narrower claim theories; range supports broader ones |
| Sorbitol amount and osmolality |
1 (6.4%), 2 (0.1–10), 3 (0.1–10), 24–27 (220–350; 250–320) |
Percentage can evade value-limited claims; osmolality window can still catch functional formulations |
| Preservative system (benzalkonium chloride) |
1 (0.025%), 3 (0.001–0.5), 23 (0.001–0.5) |
Lower/higher BA ranges affect Claim 1; Claim 3/23 allow wide window |
| Citrate (sodium citrate dihydrate) |
1 (0.068%), 3 (0.068%), 22–23 (0.068% fixed in 23) |
Fixed citrate level is a strong differentiator |
| Delivery device |
4–12 (bottle + pump + metered multi-dose) |
Device classification and actuation mode may determine dependent-claim viability |
| Spray volume per actuation |
16–21 (0.07–0.15; ~0.14) |
Metering volume outside window avoids these dependent claims |
What is the likely US patent landscape around US 8,071,073 for azelastine nasal formulations?
This section requires Orange Book and patent-family data to be complete and accurate. The information provided contains only the claim text and does not include:
- the patent assignee/filing dates,
- priority claims,
- continuation status,
- prosecution history,
- related patents in the same family,
- Orange Book listings for the relevant marketed azelastine nasal product,
- any Paragraph IV/Biosimilar/generic litigation records.
Because you requested a detailed scope and patent landscape analysis in the US, producing a landscape without those identifiers would risk factual errors. Per operating constraints, no partial landscape is provided.
Key Takeaways
- US 8,071,073 is primarily a formulation patent for intranasal azelastine hydrochloride targeting allergic rhinitis and non-allergic vasomotor rhinitis, with excipient choices that center on sucralose + sorbitol-based tonicity/osmolality and a defined citrate/preservative/viscosity/chelator system.
- Independent scope is split across:
- Claim 1: tight fixed excipient “signature” at 0.100% azelastine and 0.150% sucralose plus fixed benzalkonium and sorbitol levels.
- Claim 2: broader concentration ranges for azelastine (0.1–0.15%), sucratose/sucralose (0.1–0.15%), and sorbitol 70% (0.1–10%).
- Claim 3: fixed 0.150% azelastine and 0.150% sucralose with a broad benzalkonium window and broad sorbitol window.
- Strong infringement pressure points for challengers are:
- matching the sucralose level (Claims 1, 3, 28) or the sucralose range (Claim 2),
- matching osmolality windows tied to sorbitol (Claims 24–27),
- keeping sodium citrate dihydrate at 0.068% when using the claim chains that fix it (Claims 1, 3, 23).
- Device and dosing: dependent claims add bottle + metered multi-dose pump and ~0.07–0.15 mL per spray constraints; these can offer design-around paths if the product’s mechanics or metered volume sit outside the claim language.
FAQs
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If a generic changes benzalkonium chloride concentration, which claims still create exposure for US 8,071,073?
Focus on Claim 1’s fixed ~0.025% benzalkonium; Claim 3 and Claim 23 allow 0.001–0.5% so higher/lower within that window may not avoid.
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Does matching azelastine concentration alone determine infringement of Claim 2?
No. Claim 2 requires matching the combined presence/concentration targets for azelastine plus sucratose/sucralose plus sorbitol ranges.
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How can a product avoid Claims 24–27 without changing azelastine and sucralose?
By reformulating to land outside 220–350 mOsmol/kg (or outside 250–320 mOsmol/kg if the narrower chain is asserted).
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What packaging features matter most for dependent claims 4–12?
Whether the device is a bottle with a pump and whether the pump is a metered multi-dose pump.
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Is the per-spray volume a critical design-around parameter?
Yes for Claims 16–21: formulations delivering outside 0.07–0.15 mL per spray can avoid those dependent limitations.
References
No references are included because the request did not provide bibliographic details for US 8,071,073 beyond claim text, and a landscape requires Orange Book, patent family, and litigation sources that are not supplied in the prompt.
