US Patent 10,335,391: Scope, Claims, and US Landscape for Topical 1.0% Oxymetazoline HCl in Rosacea Erythema
US Patent 10,335,391 claims method-of-treatment coverage for rosacea-associated facial erythema using a once-daily topical pharmaceutical composition containing 1.0% (w/w) oxymetazoline hydrochloride as the sole active ingredient, with multiple claim layers that narrow to formulation type (cream and excipient set), clinical endpoints, and systemic exposure thresholds (Tmax/Cmax/AUC), plus a central “no rebound or worsening” limitation.
What does the patent claim cover at the headline level?
Core invention (method of treatment)
The broadest claim set in your text is framed as:
- Indication: “facial erythema associated with rosacea”
- Population: patient in need; adult dependent in dependent claims
- Dose & dosing frequency: once daily
- Site/route: topical administration on the face
- Drug substance: oxymetazoline hydrochloride
- Active ingredient scope: 1.0% w/w and sole active ingredient
- Clinical/utility limitation: “patient experiences no rebound or worsening of facial erythema post-treatment”
- Efficacy metrics: improvement on Clinician’s Erythema Assessment (CEA) and/or Subject Self-Assessment of Erythema (SSA) at specified grade thresholds
- Exposure profiling limitations: median Tmax, mean Cmax, and AUC0-24 after 28 days of topical administration
The claims are written so that infringement turns on whether a method delivers these outcomes and exposure metrics in the claimed dosing context.
Claim scope is method-dominant, not product-dominant
Even where the formulation is described, the grant is primarily a method of treating claim. That matters because it gives the patentee leverage over:
- who performs the method (treating clinician, patient with instruction, distributor)
- what is administered (must meet the claimed composition specs)
- what happens after treatment (no rebound/worsening; CEA/SSA improvement)
- whether systemic exposure is within claimed bounds
How broad is coverage across patient treatment variations?
Treatment variables that are explicitly locked
Across the claim set in your text, the locked elements include:
- Drug: oxymetazoline HCl
- Strength: 1.0% w/w
- Timing: “once daily”
- Anatomic placement: “on the site of erythema on the face” and, in dependent claims, thin-layer coverage of entire face avoiding eyes and lips
- Active ingredient limitation: sole active ingredient
- Rebound/worsening: no rebound or worsening post-treatment
Treatment variables that expand but still remain within guardrails
The claims expand allowable dosage form forms through a dependent chain:
- solutions, gels, lotions, creams, ointments, foams, emulsions, microemulsions, milks, serums, aerosols, sprays, dispersions, microcapsules, vesicles, microparticles
This appears in your claim 2 as a broad dosage form selection.
But coverage is later narrowed to:
- cream (dependent claim 3, repeated in the second independent claim sequence)
Patient subset narrowing
Dependent claims further narrow:
- persistent facial erythema (claims 15, 26, and similarly in the second set)
- adult (claims 16, 27, and repeated)
- “pea sized amount” (claim 17) in one dependent chain
Taken together, the patent gives a layered infringement map: broad base for any qualifying patient, then narrower versions that reduce design-around space by anchoring to persistent erythema, adult patients, and specific dosing volume or application geometry.
What are the independent claims and what differentiates them?
Your text provides three independent claim anchors:
- Claim 1: method with “no rebound or worsening,” 1.0% w/w oxymetazoline HCl as sole active ingredient, once daily topical administration to erythema site on face, with “no rebound/worsening” limitation; additional dependent claim structure provides form, efficacy, exposure.
- Claim 18: same method concept, but it is the second independent claim sequence (it mirrors claim 1 in your text).
- Claim 28: same concept but stripped of the clinical “no rebound or worsening” language in the version you provided (it reads as a bare method of treating facial erythema associated with rosacea comprising once daily topical administration of 1.0% oxymetazoline HCl as sole active ingredient).
Practical effect of the three independent claim frames
- Claims 1 and 18: include the most behavior-defining limitation: “no rebound or worsening.”
- Claim 28: may be easier to satisfy if “rebound/worsening” is contested, because your provided wording removes that phrase from the independent claim text.
However, dependent claims tied to efficacy and exposure still impose substantial objective constraints. Even if “rebound” is absent in claim 28, the dependent layers can still narrow infringement.
What does each claim layer practically require (element-by-element)?
Drug substance and formulation features
- Oxymetazoline HCl concentration: 1.0% w/w (claims 1, 18, 28 and formulation-dependent claims)
- Sole active ingredient: oxymetazoline HCl only (claims 1, 18, 28)
Dosage forms
- Any of the listed dosage forms (claim 2)
- Cream is expressly covered (claim 3, and in the second set claims 20-21 and 30-31)
Excipient set (cream-specific dependent limitation)
Your provided claims specify a defined excipient constellation in claims 5-6, and repeated in 20-21 and 30-31. The quantitative set includes:
- 1.0% w/w oxymetazoline HCl
- 0.2% w/w methylparaben
- 0.05% w/w propylparaben
- 0.8% w/w phenoxyethanol
- 0.3% w/w sodium citrate dihydrate
- 0.219% w/w anhydrous citric acid
- 0.01% w/w disodium edetate
- 0.05% w/w butylated hydroxytoluene
- 2% w/w anhydrous lanolin
- 7% w/w medium chain triglycerides
- 7% w/w diisopropyl adipate
- 7% w/w oleyl alcohol
- 4% w/w polyethylene glycol PEG-300
- 8% w/w polyethylene glycol PEG-6 / polyethylene glycol PEG-32 / glycol stearate (Tefose-63)
- 8% w/w cetostearyl alcohol
- 2% w/w ceteareth-6 / stearyl alcohol (Cremophor A6)
- 2% w/w ceteareth-25
- purified water (q.s.) (cream adjuvant balance)
That excipient block is the main design-around pressure point: if a competitor uses the same oxymetazoline concentration but shifts the excipient architecture, they may still land in claims that do not require the excipient set (depending on whether infringement is asserted under the broader dosage-form claims versus the cream-specific dependent claims).
Treatment outcomes (efficacy grading)
- At least 2-grade improvement on CEA and/or SSA (claim 8, also 22 in the second sequence)
- At least 1-grade improvement on CEA and/or SSA (claim 9)
These are outcome-based limitations. In practice, they require that the treated patient population and treatment schedule yield these grade improvements as measured on those scales.
Systemic exposure constraints (28-day profiling)
Several dependent claims lock objective PK windows/thresholds after 28 days:
- Median Tmax: about 10 to 12 hours (claims 10 and 23)
- Mean Cmax: less than about 133.5 pg/mL (claims 11 and 24)
- Patient-specific mean Cmax: less than about 66 pg/mL (claims 12 and as mirrored structure)
- AUC0-24: less than about 2042 pg·hr/mL (claims 13 and 25)
- AUC0-24: less than about 1050 pg·hr/mL (claims 14)
The presence of multiple thresholds gives multiple routes for a patentee to assert infringement depending on how exposure is reported (mean versus narrower subsets, and AUC cut points).
Additional method constraints
- Persistent facial erythema: covered (claims 15, 26, and mirrored)
- Adult: covered (claims 16, 27)
- Application volume: “pea sized amount” (claim 17)
- Application geometry: thin layer covering entire face avoiding eyes and lips (claim 19, 29)
What is the patent’s claim strategy from a design-around perspective?
Tight coupling of three themes: drug dose, clinical outcome, and systemic exposure
The strongest tightening features are:
- Oxymetazoline at 1.0% w/w as sole active ingredient
- Efficacy thresholds on CEA/SSA with specified grade changes
- PK guardrails after 28 days (Tmax/Cmax/AUC)
A competitor cannot simply change excipients, vehicle, or manufacturing method and assume escape if the alternative formulation still yields:
- the same systemic exposure regime
- the same clinical improvement magnitude
- absence of rebound/worsening (for claims 1 and 18)
Cream-excipient block is a secondary tightening layer
The excipient list is a strong constraint only if asserted under the cream-dependent dependent claims (3/5/6 and 20-21 and 30-31). A competitor could potentially avoid that specific dependent claim scope by changing the cream base excipient composition, while still remaining exposed under broader dosage form claims (claim 2) if infringement is asserted on claim 1/18/28 plus the non-excipient-dependent features.
Where does this place the patent in the broader US oxymetazoline-and-rosacea landscape?
What can be said strictly from your provided claim text
Your excerpt indicates the patent’s IP position depends on:
- oxymetazoline HCl topical use at 1.0% for rosacea erythema
- once-daily regimen
- controlled systemic exposure profile
- clinical improvement on CEA/SSA
- no rebound/worsening post-treatment
This positions the patent as part of the family of claims that attempt to turn a known active into an enforceable “method profile” by adding objective constraints.
What cannot be stated without verified patent bibliographic data
Your prompt does not include:
- the patent’s publication/application numbers
- priority dates
- assignee
- prosecution history
- claim charts from related documents
- citations to other patents within the family
- whether this patent is a continuation/divisional
- expiration date or terminal disclaimer status
- whether related US patents exist with earlier or later priority
Because those are not included in your inputs, a complete, accurate US landscape mapping (overlapping claims across families, blocking/non-blocking status, ANDA/505(b)(2) style freedom-to-operate analysis) cannot be produced correctly.
Accordingly, the landscape discussion below stays within the safe boundary set by your claim set alone: where the claim scope sits conceptually, and what adjacent freedom-to-operate risks are implied by the claim features.
In-scope subject matter map: what a potential entrant must avoid
Avoid triggering the method-of-treatment claims
A method is at risk if it meets all the core elements:
- patient has rosacea-associated facial erythema
- treatment uses a once-daily topical composition on the face
- the composition has 1.0% w/w oxymetazoline HCl
- oxymetazoline HCl is the sole active ingredient
- the method results in “no rebound or worsening” (for claims 1 and 18)
- efficacy grades reach the claimed improvements
- systemic exposure in the treated population meets the claimed PK thresholds (for relevant dependent claims)
Design-around levers that are implied by the claim wording
A formal design-around would need to break at least one of the required constraints. From the claim structure, the most direct levers are:
- concentration change: move away from 1.0% w/w (note: dependent claim structure repeatedly anchors to 1.0%)
- active ingredient scope: introduce another active (breaking “sole active ingredient”) or remove oxymetazoline
- dosing regimen: switch from once daily
- endpoint strategy: target outcomes that do not meet the “at least 1-grade / at least 2-grade improvement” thresholds on CEA/SSA
- exposure strategy: alter formulation and delivery so that Tmax/Cmax/AUC exceed the claimed thresholds (this is hard because it is outcome tied to PK)
- rebound behavior: induce or tolerate “worsening/rebound” after treatment for claims 1 and 18 (commercially unattractive and clinically risky, but it is an explicit limitation)
Claim-by-claim compact table (your excerpt as the operative scope)
| Claim |
Key limitation(s) in your excerpt |
| 1 |
Once daily topical on face for rosacea facial erythema; 1.0% w/w oxymetazoline HCl as sole active; “no rebound or worsening” after treatment |
| 2 |
Dosage form selection includes solutions, gels, lotions, creams, etc. |
| 3 |
Dosage form is cream |
| 4 |
Well tolerated and limited systemic exposure (general) |
| 5 |
Cream further comprises listed preservatives/stabilizers/hydrocarbon emulsifiers and excipients (non-quantified list) |
| 6 |
Quantified cream composition (1.0% oxymetazoline HCl plus excipient stack with specific % values) |
| 7 |
Repeats “well tolerated” and limited systemic exposure |
| 8 |
Treatment yields ≥2-grade improvement on CEA/SSA |
| 9 |
Treatment yields ≥1-grade improvement on CEA/SSA |
| 10 |
Median Tmax after 28 days about 10-12 h |
| 11 |
Mean Cmax after 28 days <133.5 pg/mL |
| 12 |
Patient mean Cmax after 28 days <66 pg/mL |
| 13 |
AUC0-24 < 2042 pg·h/mL |
| 14 |
AUC0-24 < 1050 pg·h/mL |
| 15 |
Facial erythema is persistent |
| 16 |
Patient is adult |
| 17 |
Once daily amount is pea sized |
| 18 |
Independent method, same core concept as claim 1 in your text |
| 19 |
Thin layer covering entire face; avoid eyes and lips |
| 20 |
Cream further comprises excipient list |
| 21 |
Quantified cream composition (same stack as claim 6) |
| 22 |
≥2-grade improvement on CEA/SSA |
| 23 |
Median Tmax after 28 days about 10-12 h |
| 24 |
Mean Cmax after 28 days <133.5 pg/mL |
| 25 |
AUC0-24 < 2042 pg·h/mL |
| 26 |
Facial erythema is persistent |
| 27 |
Patient is adult |
| 28 |
Independent method of treating; once daily topical; 1.0% w/w oxymetazoline HCl as sole active (no rebound language not shown in your excerpt) |
| 29 |
Thin layer covering entire face; avoid eyes/lips |
| 30 |
Cream further comprises excipient list |
| 31 |
Quantified cream composition |
| 32 |
≥2-grade improvement on CEA/SSA |
| 33 |
Median Tmax about 10-12 h |
| 34 |
Mean Cmax <133.5 pg/mL |
| 35 |
AUC0-24 < 2042 pg·h/mL |
| 36 |
Facial erythema is persistent |
| 37 |
Patient is adult |
Key Takeaways
- US Patent 10,335,391 is enforced through method-of-treatment claims anchored to once-daily topical 1.0% oxymetazoline HCl as the sole active ingredient for rosacea facial erythema.
- The claims add enforceable constraints beyond active ingredient and indication: (i) “no rebound or worsening” in claims 1 and 18, (ii) clinical grading thresholds on CEA/SSA, and (iii) 28-day systemic exposure limits (Tmax/Cmax/AUC).
- Cream-dependent claims in your excerpt impose a specific excipient stack with quantitative percentages, creating a second-tier design-around path only if infringement is asserted on those dependent claim ranges.
- The practical infringement test becomes whether a treated patient population meets both efficacy and exposure limitations, not just whether the product contains oxymetazoline HCl.
FAQs
1) Does the patent protect oxymetazoline cream only, or multiple dosage forms?
It protects methods using multiple dosage forms via the dosage form selection in dependent claim 2, while cream is expressly covered in dependent claims.
2) What is the single biggest parameter tied across the independent method claims in your text?
The composition strength and active ingredient definition: 1.0% w/w oxymetazoline hydrochloride as the sole active ingredient with once-daily topical facial administration.
3) What makes the claims harder to design around than a standard “use of drug” claim?
The claims incorporate objective PK limits after 28 days (median Tmax, mean Cmax, AUC0-24) and CEA/SSA grade improvement thresholds, plus “no rebound or worsening” in claims 1 and 18.
4) If a competitor changes excipients but keeps 1.0% oxymetazoline, is that necessarily outside scope?
Not necessarily. Excipient specificity appears in dependent cream claims; broader dosage-form and method claims may still apply if other limitations are met.
5) Is “persistent facial erythema” required for all claims?
No. It appears in dependent claim limitations (e.g., claims 15/26/36), while other dependent claims cover adult status and dosing/application specifics.
References
[1] User-provided claim text for US Drug Patent 10,335,391 (claims 1-37 excerpt).
