Scope and Patent Landscape for US Drug Patent 10,478,502 (Topical Corticosteroid + Diethyl Sebacate, No White Petrolatum)
US Patent 10,478,502 claims a topical pharmaceutical composition built around a specific liquid oil carrier (diethyl sebacate) combined with a corticosteroid at <0.05%, with an explicit excision of white petrolatum, plus multiple dependent claim constraints on oil loading, steroid subclasses, formulation type, and treatment method. The patent’s practical enforcement value will concentrate on products that (i) use diethyl sebacate as a primary solubilizing oil, (ii) include a very low-dose corticosteroid concentration window (especially halobetasol propionate at ≤0.03% or ≤0.01%), and (iii) avoid white petrolatum, while also potentially matching emulsion architecture and form-factor (lotion/gel/cream/ointment).
The overall landscape is dominated by: (1) older topical corticosteroid formulation IP (carriers, solubilizers, emulsions), (2) modern “non-petrolatum” / cosmetically elegant vehicles, and (3) newer specific carrier patents around sebacate esters and solubilization approaches. Without the patent text for the full specification (preferred embodiments, definitions of “white petrolatum,” and the exact solubilization test method), enforcement will be strongest where a defendant’s product matches the claim-measured features: diethyl sebacate, <0.05% corticosteroid, and petrolatum-free status, with secondary leverage from the halobetasol propionate low-dose and oil concentration sufficiency limitations.
What does US Patent 10,478,502 claim for topical pharmaceutical compositions using diethyl sebacate?
Core independent claim (Claim 1) is a three-part composition definition:
- Topical pharmaceutical composition for skin.
- Liquid oil component comprising:
- diethyl sebacate, and
- a corticosteroid selected from:
- halobetasol propionate
- clobetasol propionate
- betamethasone dipropionate
- diflorasone diacetate
- fluocinonide
- corticosteroid concentration <0.05%.
- Aqueous component comprising water.
- The composition is free of white petrolatum.
Interpretive anchors for claim construction
- “Free of white petrolatum” is a categorical vehicle exclusion. If the accused product uses white petrolatum (even as a minority excipient) it should fall outside Claim 1 on its face.
- “Liquid oil component comprising diethyl sebacate” does not require diethyl sebacate to be the only oil. Claim 2 later confirms oil can include mineral oil or light mineral oil, implying broader oil compatibility.
- Steroid concentration: Claim 1 sets a ceiling at <0.05%. Dependent claims narrow key steroid dose embodiments (halobetasol only) further.
Which corticosteroids are explicitly covered and what concentration windows matter?
Claim 1 covers five corticosteroids, but only the dose ceiling in Claim 1 applies to all five.
| Corticosteroid (Claim 1 list) |
Concentration limitation in Claim 1 |
Additional narrower constraints in dependent claims |
| Halobetasol propionate |
<0.05% |
Claim 3: ≤0.03% (w/w); Claim 4: ≤0.01% (w/w) |
| Clobetasol propionate |
<0.05% |
None stated in the provided claim set |
| Betamethasone dipropionate |
<0.05% |
None stated in the provided claim set |
| Diflorasone diacetate |
<0.05% |
None stated in the provided claim set |
| Fluocinonide |
<0.05% |
None stated in the provided claim set |
Practical enforcement implication
- The patent’s “highest probability” hook for low-dose halobetasol products is Claim 3 and Claim 4, which target ≤0.03% and ≤0.01% formulations. If a generic or licensee shifts to clobetasol or betamethasone dipropionate, Claim 1 still applies, but the “tight dose” dependent claims may not.
How broad is the diethyl sebacate scope across oil types and emulsion systems?
Claim coverage is broad on:
- Steroid selection (five specific corticosteroids).
- Oil system flexibility (Claim 2 adds mineral oil/light mineral oil; Claim 8 allows additional emulsifiers).
- Dosage form and emulsion architecture (Claim 11 and Claim 12).
Claim coverage is narrower on:
- Vehicle exclusion (no white petrolatum).
- Oil solubilization loading limitations that appear in Claims 5 to 7 (only relevant for products that also match that oil concentration feature).
What additional excipient features are required or permitted by dependent claims?
| Dependent claim |
Additional limitations to Claim 1 |
| Claim 2 |
Liquid oil component further comprises mineral oil or light mineral oil |
| Claim 8 |
Liquid oil component further comprises an emulsifying agent |
| Claim 9 |
Aqueous component further comprises one or more of: humectants, preservatives, chelating agents, emulsifying agents, thickening agents |
| Claim 10 |
Composition further comprises a pH adjusting agent |
These do not narrow the patent to a single “signature” formula. They provide a claim pathway where emulsifier/humectant systems can vary while staying within the covered composition frame.
What dosage forms and emulsion architectures are explicitly claimed? (Formulation scope)
Claim 11 and Claim 12 explicitly cover multiple dispersion structures and product presentations:
Emulsion architecture (Claim 11):
- oil-in-water
- water-in-oil
- oil-in-water-in-oil
- multivesicular emulsion
Dosage form (Claim 12):
- lotion
- gel
- cream
- ointment
Enforcement implication
- A defendant cannot evade merely by changing from cream to gel or switching emulsion type, if the product still uses diethyl sebacate, stays <0.05% steroid, and is petrolatum-free.
What “oil concentration sufficient to dissolve” limitations change the infringement risk profile?
Claims 5 to 7 introduce a functional concentration limitation that can be meaningful in both validity and infringement analyses:
- Claim 5: liquid oil concentration is sufficient to dissolve the amount of corticosteroid at 22°C ± 2°C.
- Claim 6: oil concentration is between 1.5 and 3 times the amount required for complete solubilization at 22°C ± 2°C.
- Claim 7: oil concentration is between 1.75 and 2.75 times the solubilization requirement at 22°C ± 2°C.
How this affects product design and claim matching
- A formulation could meet Claim 1’s composition ingredients but attempt to argue it is formulated to avoid the particular “multiple-of-solubilization” ratio. If a competitor designs toward a different solubilization regime (for example, by changing steroid physical form, using alternative solubilizers, or altering oil fractions), they may attempt to reduce their overlap with Claims 5-7 even if Claim 1 remains reachable.
Enforcement implication
- Claims 5-7 look like “manufacturing-controlled” claim elements tied to measurable solubilization behavior, which can become the center of expert-driven infringement analyses.
Does US 10,478,502 claim both composition and method-of-use? What skin indications are covered?
Yes. The patent includes a method-of-use set:
Method claim scope (Claims 13 to 16)
- Claim 13: treating a skin disorder amenable to topical corticosteroid therapy by applying the Claim 1 composition.
- Claim 14: listed disorders:
- psoriasis
- atopic dermatitis
- contact dermatitis
- hand dermatitis
- eczema
- poison ivy dermatitis
- Claim 15: treatment period up to two weeks
- Claim 16: treatment period longer than two weeks
Practical enforcement implication
- If a product is covered by Claim 1, method claims reduce design-around options because the therapeutic use is broad across common corticosteroid-responsive inflammatory dermatoses. The two-week breakpoint creates a second axis of potential tailoring, but it is less likely to be a clean design-around for routine clinical use patterns.
What patents likely compete or overlap with US 10,478,502 in the US topical corticosteroid formulation space?
A defensible landscape view depends on knowing the listed drug tied to US 10,478,502 in the Orange Book and on the full family members. The claim set alone points to an IP “center of gravity” that typically clusters around:
- Vehicle and solubilizer patents for topical corticosteroid systems using sebacate esters or specific oils.
- Emulsion and dermatologic vehicle patents that cover non-petrolatum formulations, including cosmetic “lighter feel” carriers.
- Low-dose high-potency steroid formulations where the patent story often targets bioavailability, distribution, and tolerability at ≤0.03% and ≤0.01% halobetasol equivalents.
- Method-of-use or regimen patents for treatment windows, though most regimen patents face obviousness risk absent a specific clinical rationale or measurable regimen effects.
Because the user-provided data does not include the patent’s assignee, family, priority dates, or the associated FDA product, a complete competitor-by-competitor map cannot be produced here without risking inaccuracy. Per the constraint, no incomplete or speculative citation-driven landscape can be provided.
What is the likely practical claim “core” for litigation and licensing leverage?
For business and IP strategy, the claim “core” can be distilled:
Highest-value elements
- Diethyl sebacate in the liquid oil component.
- Corticosteroid selection from the defined list.
- Corticosteroid concentration <0.05%.
- No white petrolatum.
- Oil solubilization behavior at 22°C (for dependence on Claims 5-7).
- Halobetasol low-dose windows (Claims 3 and 4).
- Emulsion architecture and dosage form (Claims 11-12 are permissive but help target common product types).
Lowest-value elements
- Aqueous excipient sub-lists (Claim 9) and pH adjusting agents (Claim 10) are likely ubiquitous and can be harder to use as discriminators unless a defendant’s product is atypical.
Key Takeaways
- US Patent 10,478,502 is an ingredient-and-vehicle anchored topical steroid formulation patent covering diethyl sebacate + one of five potent corticosteroids at <0.05%, in an aqueous system with water, and explicitly excluding white petrolatum.
- The strongest narrowing hooks are halobetasol propionate ≤0.03% (Claim 3) and ≤0.01% (Claim 4), plus the 22°C solubilization ratio constraints in Claims 5-7.
- The claim set is formulation-flexible across multiple emulsion architectures (Claim 11) and dosage forms (Claim 12), which limits superficial design-around strategies.
- The method claims cover common corticosteroid-responsive dermatoses (Claim 14) and split treatment periods ≤2 weeks vs >2 weeks (Claims 15-16), supporting use-based enforcement if composition coverage is established.
FAQs
- What ingredient is the central driver of infringement for US 10,478,502? Diethyl sebacate in the liquid oil component.
- Can a product still infringe if it uses an emulsion other than oil-in-water? Yes. Claim 11 covers oil-in-water, water-in-oil, oil-in-water-in-oil, and multivesicular emulsions.
- What change most cleanly reduces overlap with the claims? Replacing the “white petrolatum-free” requirement by using white petrolatum, or removing diethyl sebacate as the liquid oil component.
- Which dependent claims most matter for low-dose halobetasol products? Claims 3 and 4 (≤0.03% and ≤0.01% halobetasol propionate).
- Does the patent cover method-of-use beyond a two-week treatment window? Yes. Claim 16 covers applying the composition for periods longer than two weeks.
References
No citations are provided because the prompt includes only the claim text for US 10,478,502 and does not include the patent’s bibliographic details, assignee, priority dates, family members, prosecution history, Orange Book status, or any external sources to support an accurate, numbered reference list.
