Details for Patent: 5,858,383

Summary for Patent: 5,858,383

Title:	Methods and compositions for topical treatment of ectoparasites
Abstract:	Methods and compositions for the topical treatment of ectoparasites on animal skin utilizing a water-soluble or water-dispersible, substantially air-impermeable liquid composition.
Inventor(s):	Michael J. Precopio
Assignee:	SHLONOGI IRELAND Ltd , Shionogi Inc
Application Number:	US08/909,352
Patent Claim Types: see list of patent claims	Use; Composition;

United States Patent 5,858,383: Scope, Claims, and US Patent Landscape for Topical Air-Impermeable Liquid Surfactant Therapy Against Ectoparasites and Nits

What does US Patent 5,858,383 claim?

US Patent 5,858,383 claims methods and compositions for topical treatment of ectoparasites and their nits using a water-soluble or water-dispersible, substantially air-impermeable liquid containing specific “skin compatible” surfactants, with optional nits-removing enzymes, optionally thickening agents, and defined contact/removal conditions for head lice.

Core claim architecture (independent claim set)

The patent includes:

• Method claims (Claim 1 and Claim 9)
• Composition claim (Claim 11)
• Multiple dependent claims defining optional enzyme/thickener/viscosity/contact time/removal steps and dosing bands.

The claim language is dominated by a structural-functional requirement for the formulation: 1) Substantially air-impermeable liquid
2) Water-soluble or water-dispersible
3) Contains at least one surfactant selected from a long, enumerated list spanning anionic, nonionic, cationic, amphoteric, zwitterionic, polar nonionic, and soap categories
4) Topical contact sufficient to kill ectoparasites 5) Removal of the composition and dead ectoparasites from skin/scalp, typically by rinsing with water (Claim 8)

What is the claim scope in practical terms? (Claim-by-claim)

Claim 1 (method; ectoparasites on animal skin)

Step A: Apply to ectoparasite-infected animal skin a water-soluble or water-dispersible, substantially air-impermeable liquid (free-flowing to viscous) containing at least one surfactant selected from categories (a) to (g).
Step B: Leave until ectoparasites have been killed.
Step C: Remove composition and dead ectoparasites.

Claim 1 surfactant “closed set” list (as written) The surfactant must be selected from the following groups:

• (a) Synthetic anionic surfactants:

  • (i) Anionic surfactants with C8 to C26 hydrophobe and at least one water-solubilizing group selected from sulfonate, sulfate, carboxylate, phosphonate, phosphate
  • (ii) C8 to C18 acyl sarcosinates
  • (iii) Na/K salts of reaction product of higher fatty acids (C8 to C18) esterified with isethionic acid
  • (iv) Na/K salts of C8 to C18 acyl N-methyl taurides
  • (v) Na/K/ammonium alkyl phosphate esters
  • (vi) Na/K/ammonium alkyl phosphate esters containing one to about 40 moles of ethylene oxide

• (b) Nonionic surfactants:

  • (i) Condensation product of an organic hydrophobe (aliphatic/alkyl aromatic) having a carboxy/hydroxy/amido/amino group with hydrophilic ethylene oxide groups
  • (ii) Aliphatic monohydric alcohol C1 to C8 attached to oxyethylene and oxypropylene chain
  • (iii) Surfactant derived from condensation of ethylene oxide with product of reaction of propylene oxide + ethylene diamine
  • (iv) Alkyl saccharide surfactants

• (c) Cationic surfactants:

  • Surfactants with organic hydrophobe + cationic solubilizing group

• (d) Amphoteric surfactants:

  • Salts of derivatives of aliphatic amines with at least one cationic group

• (e) Zwitterionic surfactants:

  • Bettaines and sulfobetaines

• (f) Polar nonionic surfactants:

  • Hydrophilic group with semi-polar bond directly between two atoms, no net charge, and does not dissociate into ions

• (g) Soap:

  • Alkali metal/ammonium/alkanolammonium salt of a long chain fatty acid

Net effect: Claim 1 is broad on the animal and on surfactant class selection but is tight on the formulation concept: the liquid must be water-soluble/dispersible and substantially air-impermeable, plus must use at least one surfactant from the specified list.

Claim 2 (optional enzyme that loosens nits)

Adds: composition also contains effective quantity of at least one enzyme that removes nits by loosening nits from skin and hair.

Claim 3 (human scalp/head lice)

Narrows animal skin to human scalp and ectoparasite to head louse.

Claim 4 (optional thickening agent)

Adds: composition also contains a thickening agent.

Claim 5 (viscosity minimum)

Requires viscosity at least about 1 centipoise at 20°C.

Claim 6 (specific vehicle example)

Requires Step A composition is a water-based pharmaceutically acceptable jelly containing gum.

Claim 7 (contact time range)

Requires Step B contact time about 4 to about 24 hours.

Claim 8 (removal by rinsing)

Requires Step C removal by rinsing with water.

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Claim 9 (method; human scalp/head lice)

A head lice-specific method claim that largely mirrors Claim 1:

• Step A: apply water-soluble or water-dispersible, substantially air-impermeable liquid containing the same enumerated surfactant list
• Step B: leave until head lice killed
• Step C: remove composition and dead lice

Claim 10 (optional enzyme that loosens nits)

Adds enzyme effective quantity for nits removal via loosening.

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Claim 11 (composition; ectoparasites and their nits on animal skin)

Defines a product, not a method:

• Component I: the same water-soluble or water-dispersible, substantially air-impermeable liquid with enumerated “skin compatible surface active agent” list
• Component II: effective quantity of at least one enzyme that removes nits by loosening nits from skin and hair

This claim is the composition counterpart to Claims 1 and 9 but explicitly requires the enzyme component.

Claim 12 (optional thickening agent in composition)

Adds thickener to Component I.

Claim 13 (viscosity minimum in composition)

Requires viscosity at least 1 centipoise at 20°C.

Claim 14 (enzyme concentration band)

Requires Component II present in about 0.0001 to about 10% by weight.

Claim 15 (thickener + viscosity minimum)

Combines Claims 12 and 13.

Where is the real claim leverage: what elements are doing the work?

The enforceable hook is the intersection of:

1) Air-impairment mechanism via formulation attribute

• “Substantially air-impermeable liquid composition”
• This is the differentiator relative to ordinary topical lice shampoos.

2) Water-soluble/dispersible constraint

• The carrier must be water compatible while still being substantially air-impermeable.

3) Surfaction selectivity to a defined taxonomy

• Surfactant must come from the enumerated list (including specific anionic subtypes and specific phosphate/EO ranges).

4) Optional but claim-required in composition claim

• Enzyme is optional in the method set but required in Claim 11 (and dependent composition claims).

5) Specific performance ranges

• Viscosity minimums
• Contact time range in the method dependent claims
• Enzyme weight% band (Claim 14)

What does this imply for infringement analysis (formulation design)

A product can fall into the claims if it meets all of the following at the relevant claim level:

• It is a water-soluble/dispersible substantially air-impermeable liquid used topically on skin/scalp for ectoparasites/nits.
• It contains at least one surfactant from the enumerated list.
• If operating under Claim 11-type scope, it also has an enzyme loosening nits, typically in the 0.0001% to 10% band.
• If operating under dependent claim scope, additional constraints apply:
  • Thickener present (Claims 4, 6, 12)
  • Viscosity threshold (Claims 5, 13, 15)
  • Contact time (Claim 7: 4 to 24 hours)
  • Removal by rinsing (Claim 8)

What is the likely patent landscape around this claim set?

US 5,858,383’s claims sit at the junction of three technology threads commonly populated by lice/nit treatment patents and formulations: 1) Topical anti-lice treatment methods (contact-based killing and nit removal) 2) Film-forming or occlusive / air-blocking topical carriers to immobilize or suffocate lice 3) Surfactant-containing water-based vehicles and enzymatic nit-disruption (loosening)

Likely competitive patent clusters (US) that typically intersect

Given the claim content, the most frequent overlap areas in the US landscape are:

• Occlusive or air-impermeable topical compositions for head lice (formulation property driven)
• Nit removal with enzymes (enzyme identity and dose driven)
• Surfactant systems used to enable emulsification/vehicle properties while meeting “substantially air-impermeable” and “water-soluble/dispersible” criteria
• Thickened gels and viscosity-controlled variants used to extend residence time on scalp

Claim-set-driven observation on landscape positioning

• The enumerated surfactant list is unusually specific for head lice “vehicle” patents.
• The combination with an air-impermeability property narrows the competitive set relative to ordinary surfactant-based pediculicides.
• Enzymatic nit loosening is explicitly required only for the composition claim (Claim 11) and the dependent claims; method claims can still fall without enzymes depending on claim level.

How broad are Claims 1 and 9 compared with Claim 11?

Method scope (Claims 1 and 9)

• Broad carrier/vehicle definition: water-soluble or water-dispersible + substantially air-impermeable + free-flowing to viscous.
• Broad on enzyme: optional (only in dependent claims).
• Broad on skin target: animal skin in Claim 1; human scalp in Claim 9.

Composition scope (Claim 11)

• Requires the same carrier property and surfactant list.
• Requires enzyme as Component II by claim definition.
• Adds a defined enzyme concentration band in Claim 14 (dependent).

Bottom line: Claim 11 is more selective because the enzyme requirement is built into the independent composition claim.

Key Takeaways

• US 5,858,383 claims a topical, water-compatible, substantially air-impermeable liquid formulation for killing ectoparasites (including head lice), using enumerated “skin compatible” surfactants.
• Enzymatic nit loosening is optional in method-dependent claims but required in the independent composition claim (Claim 11).
• Dependent claims add practical constraints that matter for product design and potential invalidity or design-around:
  • Viscosity (>= about 1 cP at 20°C)
  • Contact time (about 4 to 24 hours)
  • Removal by rinsing with water
  • Thickening agent
  • Enzyme dose (about 0.0001 to about 10% by weight)

FAQs

1) Is the surfactant selection in 5,858,383 open-ended or limited?

Limited. The surfactant must be selected from the enumerated categories and sub-specifications in the claims (anionic, nonionic, cationic, amphoteric, zwitterionic, polar nonionic, and soap with stated parameter ranges for certain subtypes).

2) Does the patent require enzymes to kill lice?

No. Killing is tied to leaving the substantially air-impermeable surfactant liquid in contact until ectoparasites are killed. Enzymes are for nit removal (loosening nits), and they are required only for the independent composition claim (Claim 11).

3) Does the patent cover only head lice?

No. Claim 1 covers ectoparasites on animal skin; Claim 9 narrows to human scalp/head lice.

4) What formulation property is central to the claims beyond surfactants?

“Substantially air-impermeable” while remaining water-soluble or water-dispersible.

5) Which dependent claims add the most operational constraints for commercialization?

The ones that define viscosity (Claims 5 and 13), residence time (Claim 7), removal method (Claim 8), and enzyme concentration (Claim 14).

References

[1] US Patent 5,858,383. “Method for topical treatment of ectoparasites and their nits” (claims text provided in the prompt).

Drugs Protected by US Patent 5,858,383

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate