United States Patent 5,993,830: Scope, Claims, and US Patent Landscape

US Patent 5,993,830 protects a narrowly defined topical two-phase skin preparation intended to form a semi-permeable membrane on skin, with a specific compositional window and defined processing logic. The claim set also captures foam/aerosol format, preparation method, and multiple use methods for itching, irritation, infection, and allergic response, including treatment classes such as contact dermatitis and eczema.

What does the patent claim in plain technical terms?

The core independent claim defines a skin preparation containing both:

A lipophilic fatty acid phase: fatty acid C14 to C20 (or mixture) at about 5 to 8% by weight
A hydrophilic carrier system with:
- Triethanolamine: about 0.73 to 2.66%
- Monopropylene glycol: about 4.5 to 7.0%
- Polyvinyl pyrrolidone (PVP): about 1.5 to 1.97%
- Dimethyl polysiloxane (at most): at most about 5.0%
- At least one humectant selected from glycerol, sorbitol, polyethylene glycol, totaling about 1 to 2%
- Water as balance to 100%
Functional limitation: the preparation exists as a two-phase system and is capable of resulting in a semi-permeable membrane when applied to skin

Independent Claim 1 (scope anchors)

Claim 1 is the single “composition + functional behavior” anchor that all dependent composition and method-of-use claims build on.

Claim 1 composition window	Component	Claim 1 limitation
Fatty acid(s) C14-C20	about 5 to 8% by weight (or mixture)
Triethanolamine	about 0.73 to 2.66%
Monopropylene glycol	about 4.5 to 7.0%
Polyvinyl pyrrolidone	about 1.5 to 1.97%
Dimethyl polysiloxane	at most about 5.0%
Glycerol / sorbitol / polyethylene glycol (or mixture)	about 1 to 2% (at least one)
Water	balance to 100%
Additional limitation	two-phase system; forms semi-permeable membrane on skin

High-impact scope points

The fatty acid restriction is chain-length constrained (C14 to C20) and quantitative (5 to 8%).
The hydrophilic system is constrained by triethanolamine, monopropylene glycol, PVP, and a defined humectant band (1 to 2%).
The dimethyl polysiloxane is capped (not a required minimum).
The functional “semi-permeable membrane” language creates a performance-based claim element that can support arguments against formulations that differ structurally but still “act like” membranes.

How narrow is Claim 2?

Claim 2 hardcodes a preferred point estimate recipe that sits within Claim 1’s ranges.

Claim 2 composition	Component	Claim 2 limitation
Fatty acid(s) C14-C20 (mixture)	6.25%
Triethanolamine	0.91%
Monopropylene glycol	5.8%
PVP	1.69%
Dimethyl polysiloxane	0.5 to 0.95%
Glycerol/sorbitol/PEG (or mixture)	1.52%
Water	balance

This is a classic “locking” dependent claim: any competitor product matching Claim 2’s numerical profile is also within Claim 1, but the converse is not necessarily true.

What additional formats does the patent cover?

Foam and aerosols

Claim 6: the skin preparation is in the form of a foam
Claim 7: an aerosolic container comprising the foam formulation of Claim 6
Claim 3-5: if the formulation includes a frothing agent, its amount is 1.3 to 3.7%, with ~1.5% as a specific dependent value.

Key format constraints

Foam is a limiting structural/formulation constraint.
Aerosol capture is not merely a method of delivery; it is tied to a container that comprises the foam formulation.

What does the patent claim about manufacturing?

Method of preparing the skin preparation (Claim 8–11)

Claim 8 defines a multi-vessel process with agitation, order of mixing, defined reaction times, and a heat/cool sequence that culminates with adding dimethyl polysiloxane under cooling conditions.

Claim 8 steps (verbatim logic summarized) a) In water, dissolve and agitate fatty acid C14-C20 (or mixture) in a vessel to create solution A.
b) In another vessel, dissolve and vigorously agitate water + PVP.
c) Add glycerol/sorbitol/PEG (or mixture) during agitation to form solution B after reaction time tc.
d) Add solution B into the vessel holding solution A; allow reaction during reaction time td.
e) Cool by adding cold water, while agitating, then add dimethyl polysiloxane.

Thermal and timing limits (dependent)	Dependent claim	Limitation
Claim 9	at least one of steps (a) and (b): ≥ 80°C
Claim 10	at least one of steps (a) and (b): ≥ 95°C
Claim 11	tc ~30 min and td ~60 min

This manufacturing section matters for patent enforcement because:

A non-infringing composition could still infringe if the process limitations are met.
A process change that breaks sequence/order, mixing order, or temperature bands may avoid certain process claims while leaving composition claims still at issue.

What does the patent claim about uses?

Core use hook

Claim 12: method for alleviating itching or skin irritation via topical application of the Claim 1 skin preparation.

Disease/indication dependent claims

Claim 13: used to treat contact dermatitis or eczema
Claim 17: method for alleviating infection of the skin
Claim 18: method for alleviating allergic reaction to metal
Claim 19: topical application in conjunction with at least one active agent selected from:
- sunscreen / sun-filtering agent
- anaesthetic
- fungicidal agent
- bactericide
Claim 20: repeated topical application

This is a use claim bundle with broad therapeutic framing (“itching/irritation”), then narrower examples (contact dermatitis/eczema; metal allergy), then further broadening via “infection” and co-application with a range of actives.

Claim scope mapping: what would infringe?

Because Claim 1 is composition and functional membrane formation tied to a narrow chemical system, infringement risk clusters around products that match the full set of constrained components, not just one.

High infringement likelihood scenario (literal alignment)

C14-C20 fatty acid(s) at 5 to 8%
triethanolamine in the 0.73 to 2.66% band
monopropylene glycol at 4.5 to 7.0%
PVP in 1.5 to 1.97%
humectant (glycerol/sorbitol/PEG) at 1 to 2%
dimethyl polysiloxane present up to 5.0%
water balance and a formulation behavior that yields a semi-permeable membrane when applied

Process infringement scenario

Even if a formulation is close, process claims are triggered when steps (a) to (e), especially the multi-vessel order and heat/cool + polysiloxane addition, are followed within dependent ranges.

Foam/aerosol-specific infringement

If a product is the same composition but is not a foam or is not delivered via an aerosol container system as claimed, it may avoid Claims 6–7 while still potentially implicating Claims 1–2 and 12–20.

US patent landscape: what is likely around this family?

The patent landscape for a topical two-phase fatty acid/TEA/PVP/propylene glycol/dimethyl polysiloxane membrane-forming system generally clusters into three technology zones:

Dermatological film-forming or membrane-forming topical emulsions/foams
PVP + glycol + surfactant/alcohol/amine systems used for skin delivery
Silicone-modified topical foams/aerosols and barrier-formers

However, without the actual publication metadata (application number, publication date, assignee, and prosecution history), the landscape cannot be mapped to specific cited reference patents or co-pending families in a way that is provably accurate. Under strict analysis rules, the only complete and verifiable “landscape” statements available from the record provided are those that derive directly from the claim text you supplied.

Accordingly, the landscape assessment below is structured as claim-to-landscape adjacency (mechanistic and claim-element based), not as a list of named competitor patents.

Adjacency map: where competitors will likely overlap

1) Foam delivery and aerosol devices

Your claim set explicitly captures:

foam formulation (Claim 6)
aerosolic container (Claim 7)
frothing agent band (Claim 4–5)

Typical competitive overlap zones

Silicone-containing foams
Aerosolized topical barriers
Dermatological cleansing/soothing foams that also include humectant systems

2) PVP + glycol + amine systems

Claim 1 tightly coordinates:

PVP (1.5 to 1.97%)
triethanolamine (0.73 to 2.66%)
monopropylene glycol (4.5 to 7.0%)

These ingredients are common in topical carriers because they control viscosity, film behavior, and water management. The combination plus constrained ratios is what makes this patent “chemically specific” and reduces overlap with systems that vary substantially in PVP content, omit TEA, or use a different glycol or polymer.

3) C14-C20 fatty acid semi-permeable membrane formation

The functional element is anchored to:

fatty acids C14-C20 at 5 to 8%
two-phase system and semi-permeable membrane formation on skin

This is a major discriminant. Many barrier-formers use different lipids (e.g., long chain esters, ceramides, fatty alcohols), different acids (different chain length), or different membrane-forming mechanisms (crosslinked polymers instead of lipid phase behavior). Those would be adjacent but not necessarily captured by Claim 1.

4) Co-application with actives

Claims 14–20 broadly allow combination with:

sunscreen/sun-filtering agents
anesthetics
fungicidal agents
bactericides

This reduces the ability for competitors to avoid infringement simply by adding an active. If the base skin preparation still matches Claim 1, combination actives do not escape.

5) Use claims: itching, irritation, dermatitis/eczema, infection, metal allergy

The use claims expand enforceability beyond product type into treatment context:

itching/irritation (broad)
contact dermatitis/eczema (specific)
infection (broad)
allergic reaction to metal (specific)

These can matter in marketing and labeling because even if product composition matches, use claims require topical application for those therapeutic objectives.

Design-around levers apparent from the claims (practical infringement risk controls)

These are claim-element levers derived from the claim boundaries.

Composition levers

Fatty acid chain length: Claim 1 requires C14 to C20. Shifting to C12-C13, C21+, or using different lipid classes may avoid Claim 1’s fatty-acid limitation.
Fatty acid quantity: 5 to 8%. Moving outside that band avoids literal coverage.
Triethanolamine presence and level: 0.73 to 2.66% is constrained.
Monopropylene glycol: 4.5 to 7.0% is constrained.
PVP content: 1.5 to 1.97% is constrained.
Humectant band: glycerol/sorbitol/PEG must total 1 to 2%.
Semi-permeable membrane performance: if a product does not achieve the claimed membrane function, it may avoid infringement of Claim 1 even if some components overlap (enforcement would likely focus on performance evidence).

Format levers

Avoid foam/aerosol: deliver via a non-foam vehicle or different packaging architecture that does not meet Claims 6–7.

Process levers

Heat/cool timing and sequence: Claim 8 requires the staged mixing, reaction times, and the cooling + polysiloxane addition step. A substantially different process sequence, mixing order, or absence of the defined thermal conditions may avoid process claims (even if composition claims still apply).

What is the enforcement footprint by claim type?

Claim type	Independent or dependent	Enforceability driver
Composition (Claim 1)	independent	product formulation and functional membrane behavior
Specific composition (Claim 2)	dependent	numerical match to a preferred recipe
Foam and aerosol (Claims 3–7)	dependent	dosage form and delivery architecture
Manufacturing process (Claims 8–11)	dependent	process steps, temperatures, and addition points
Therapeutic uses (Claims 12–20)	dependent	indication, labeling, and topical application for the claimed therapeutic purpose

Net effect: the patent is structured to create multiple “landing zones” for enforcement: product, dosage form, packaging, manufacturing process, and therapeutic use.

Key Takeaways

US 5,993,830 centers on a two-phase, semi-permeable-membrane-forming topical skin preparation built from a C14-C20 fatty acid at 5–8% plus a constrained hydrophilic system (TEA, monopropylene glycol, PVP, humectant band) and optional capped silicone (dimethyl polysiloxane up to 5%).
The patent also covers foam and aerosolic containers, with frothing agent constrained to 1.3–3.7% (with ~1.5% as a dependent target).
The manufacturing claims are explicit: multi-vessel staged dissolution with agitation, defined tc/td reaction times, a heat window (at least one of steps at ≥80°C or ≥95°C), and cooling plus dimethyl polysiloxane addition.
Use claims cover itching/irritation broadly and extend to contact dermatitis/eczema, skin infection, and metal allergy, with allowed co-application actives (sunscreens, anesthetics, fungicides, bactericides).
Risk is driven less by the presence of any single ingredient and more by meeting the full “locked recipe” structure (composition and functional membrane formation), plus dosage form (foam/aerosol) for those dependent claims.

FAQs

1) Is US 5,993,830 primarily a composition patent or a method patent?

It is primarily a composition and formulation patent (Claim 1), with additional coverage for foam/aerosol format, a detailed manufacturing method, and multiple therapeutic use methods.

2) What is the most critical compositional limitation in Claim 1?

The most critical is the combined requirement for a C14-C20 fatty acid at about 5 to 8% plus the constrained hydrophilic matrix (triethanolamine, monopropylene glycol, PVP, and 1–2% humectant) in a formulation that forms a semi-permeable membrane on skin.

3) Does adding unrelated actives avoid the patent?

No. Claim 19 explicitly allows topical application in conjunction with various actives (sunscreen/sun-filtering agents, anesthetics, fungicidals, bactericides). If the base preparation matches Claim 1, adding actives does not remove coverage.

4) Are foam and aerosol claims optional or separate?

Foam is separately claimed (Claim 6) and aerosol container usage is separately claimed (Claim 7). A formulation matching Claim 1 but delivered in a non-foam form may still implicate Claim 1 and use claims, while potentially avoiding Claims 6–7.

5) How do the manufacturing claims impact product freedom?

They add an enforceable path based on process compliance: defined temperatures, reaction order, mixing steps, and timed addition/cooling logic. A company that replicates composition but changes process sequence or thermal profile can reduce exposure on the process claims, while composition and use claims may still remain.

References (APA)

[1] United States Patent No. 5,993,830.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Sweden	9700129	Jan 17, 1997

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	283684	⤷ Start Trial
Australia	5786198	⤷ Start Trial
Australia	744980	⤷ Start Trial
Brazil	9806774	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,993,830

Summary for Patent: 5,993,830