Scope, Claims, and US Patent Landscape for US Drug Patent 5,006,342

US Patent 5,006,342 claims a transdermal drug-delivery device built as a solid-state laminated composite that is non-occlusive (or not occlusive), includes elastomeric structural laminas to match skin expansion/contraction, and uses viscoelastic hydrophobic polymer laminas and a pressure-sensitive adhesive (PSA) lamina that both avoid “rate-controlling barrier to diffusion”. The claims also tightly couple drug classes (notably steroids including estradiol, and fentanyl/fentanyl analogs) with a specific solubility/permeation enhancer chemistry centered on propylene glycol monolaurate/dilaurate.

What do the independent claim elements require?

Claim 1: What the device must contain, structurally and functionally

Claim 1 requires the following integrated architecture and functional diffusion language:

Claim 1 requirement	Claim 1 language captured as scope	Practical read-through
Device form	“transdermal drug-delivery device” as “solid state laminated composite” adhered to “unbroken skin”	Must be a laminate stack (not a reservoir gel, not a microemulsion, not a matrix-only sheet).
Mechanical compliance	“mechanical properties that enable it to expand and contract in concert with the normal expansion and contraction of said area of skin”	Structural layers must provide flexibility and dynamic mechanical compliance.
Structural elastomer laminas (at least 2)	“at least two spaced structural laminas of a resilient elastomeric polymer, one of which forms the upper face surface”	Must include at least two resilient elastomeric polymer layers; one is the “upper face surface.”
Viscoelastic hydrophobic polymer lamina positioned between structural laminas	“at least one lamina of a viscoelastic hydrophobic polymer” positioned between structural laminas	Must have at least one interposed “viscoelastic hydrophobic polymer” layer.
Solubility/permeation enhancer and/or drug dispersed and at least partly dissolved in hydrophobic layer	enhancer and/or drug “dispersed and at least partly dissolved” in viscoelastic hydrophobic polymer	Requires molecular-level solubility/partial dissolution in that hydrophobic polymer, not merely surface mixing or mechanical entrapment.
No rate-controlling diffusion barrier in structural laminas	“structural lamina(s) underlying the viscoelastic hydrophobic polymer lamina(s) providing no rate-controlling barrier to diffusion”	The structural layers must not act as the diffusion bottleneck from the hydrophobic layer to skin.
PSA lamina containing drug/enhancer	“a lamina of a pharmaceutically acceptable pressure-sensitive adhesive” with drug and/or enhancer “dispersed and at least partly dissolved”	PSA layer itself must solubilize/contain the drug/enhancer, not just hold it superficially.
No rate-controlling barrier in PSA for diffusion	PSA lamina “providing no rate-controlling barrier to diffusion”	Again enforces that PSA does not become the diffusion bottleneck.
Placement of drug and/or enhancer between layers (proviso)	“proviso that at least one of said viscoelastic hydrophobic polymer lamina(s) and said pressure-sensitive adhesive lamina contains the drug”	Drug must be in at least one of the two specified layers (hydrophobic layer or PSA layer).

Scope hinge: Claim 1 is not merely “a transdermal patch.” It is a layered diffusion system where two classes of polymers (viscoelastic hydrophobic polymer and PSA) both contain drug/enhancer, while the elastomeric structural layers are included for mechanical compliance and are expressly required not to be diffusion barriers. This combination of (i) laminate stack + (ii) partial dissolution in specific layers + (iii) “no rate-controlling barrier” narrows the claim scope relative to generic multilayer patches.

Dependent claim structure: how specificity builds

The dependent claims progressively narrow by (1) water vapor transmission/“non-occlusive” behavior, (2) drug identity (steroid and fentanyl families), and (3) enhancer chemistry and polymer exemplars.

Claim-by-claim scope map (1–21)

Claim 2: Does the device require enhancer distribution

Claim 2 states: “at least one of said lamina(s) of viscoelastic hydrophobic polymer and said lamina of pharmaceutically acceptable pressure-sensitive adhesive contains said agent.”

Scope impact: It does not require the enhancer in both layers. Claim 2 preserves coverage where the agent is in one of the two specified layers.

Claims 3 and 4: Non-occlusive and water vapor transmission

Claim 3 adds: device is “a sufficient barrier to water vapor transmission that said area of skin becomes hydrated when the device is placed thereon.”

Claim 4 specifies: “viscoelastic hydrophobic polymer lamina(s) provide(s) said barrier to water vapor transmission.”

Scope impact: The viscoelastic hydrophobic layer must do the water vapor barrier role. This aligns with Claim 8 and Claim 9.

Claims 5–7: Drug identity

Claim 5: “drug is a steroid”
Claim 6: “drug is estradiol”
Claim 7: “drug is fentanyl or a fentanyl analog”

Scope impact: The claim family is not limited to one indication. It explicitly covers estradiol and fentanyl families within the same laminate architecture.

Claims 8 and 9: Not occlusive + quantified WVTR

Claim 8: device “is not occlusive”
Claim 9: WVTR of device is 11–18 g/m²-hr

Scope impact: This is a hard boundary. Many transdermal patches are designed to be occlusive or semi-occlusive. Claim 9 limits coverage to WVTR in a defined band.

Claims 10 and 11: Distribution constraint (drug in PSA, agent in PSA, plus hydrophobic layer)

Claim 10: “drug contained in PSA lamina” and “agent contained in PSA lamina” and “at least one viscoelastic hydrophobic polymer layer” (contains something; the claim anchors the presence of that layer).
Claim 11: same structure but with the added context of “drug” matching Claim 3 (so water-vapor/hydration and steroid context).

Scope impact: These claims force a specific distribution: drug in PSA and agent in PSA, with the hydrophobic layer still present.

Claim 12: Enhancer chemistry (C2–C4 alkanediol fatty esters/ethers)

Agent is: “a fatty acid ester or fatty alcohol ether of a C2 to C4 alkanediol” with each fatty portion C8–C22.

Scope impact: Establishes the chemical class boundary. It is broader than only laurates but requires both diol backbone constraint and C8–C22 fatty portion constraint.

Claim 13: Estradiol/fentanyl with propylene glycol fatty mono-/di-esters

If drug is estradiol or fentanyl analog, agent is limited to:

fatty acid monoester of propylene glycol where fatty acid is C8–C22, or
mixture with fatty acid diester of propylene glycol where fatty acid is C8–C22.

Scope impact: Introduces propylene glycol and narrows to monoester/diester form.

Claims 14 and 18: Specific enhancers

Claim 14: propylene glycol monolaurate + propylene glycol dilaurate (when diester included)
Claim 18 adds quantitative loading ranges in the PSA and hydrophobic layers:
- Estradiol/fentanyl (or analog) loading in PSA: 1–20 wt% (based on mixture)
- Propylene glycol monolaurate loading in PSA: 2–20 wt%
- Monolaurate or (mono + dilaurate) in each hydrophobic layer: 5–15 wt%

Scope impact: These are strong “numerical guardrails.” A competing patch that uses different enhancer chemistries or different loading regimes is less likely to read on the narrower dependent claims.

Claims 15–16 and 17 and 20: Polymer exemplars and specific material pairing

Claim 15: elastomer examples (polyether block amide, polyethylene methyl methacrylate block copolymer, polyurethane, silicone elastomer, polyester block copolymer hard/soft segments).

Claim 16: hydrophobic polymer examples (polysiloxane, polyacrylate, polyurethane, rubbery polymer, plasticized EVA, low MW polyether block amide).

Claim 17 narrows to:

resilient elastomer: polyether block amide or polyurethane
hydrophobic polymer: polyisobutene
PSA: polydimethylsiloxane
thickness: structural 10–75 µm, hydrophobic 50–100 µm, PSA 50–100 µm

Claim 20 repeats that specific pairing:

elastomer: polyurethane
hydrophobic: polyisobutene
PSA: polydimethylsiloxane

Scope impact: Claim 17 and 20 define a compact “core embodiment” that a competitor can try to avoid by changing polymer class pairing, thicknesses, or diffusion-bottleneck behavior.

Claim 19: A second independent-style method/device claim with a defined layer order and explicit wt% bounds

Claim 19 states a device “in the following order” and includes explicit content and “no rate-controlling barrier” language. The stack order is:

First structural lamina (resilient elastomer), forms upper face
First viscoelastic hydrophobic lamina containing 5–15 wt% propylene glycol monolaurate (or mono + dilaurate mixture)
Second structural lamina (no rate-controlling barrier)
Second viscoelastic hydrophobic lamina containing 5–15 wt% propylene glycol monolaurate
Third structural lamina (no rate-controlling barrier)
PSA lamina (basal surface, adheres to skin) containing:
- 1–20 wt% estradiol, fentanyl, or fentanyl analog
- 2–20 wt% propylene glycol monolaurate (or mono + dilaurate or dilaurate)
- “providing no rate-controlling barrier to diffusion” to skin

Scope impact: Claim 19 is narrower than Claim 1 because it enforces layer order and numerical wt% ranges with explicit drug/enhancer in defined layers.

Claim 21: Additional thickness ranges

Claim 21 repeats thickness ranges across structural, hydrophobic, PSA layers:

structural: 10–75 µm
hydrophobic: 50–100 µm
PSA: 50–100 µm

Scope impact: Confirms that the claimed embodiment uses a specific laminate thickness architecture consistent with a controlled diffusion profile while maintaining non-occlusive properties (Claims 8–9).

How this claim set defines the patent “center of gravity”

Across the dependent claims, the “repeatable technical signals” are:

Layered laminate with at least two structural elastomer layers for mechanical compliance.
Viscoelastic hydrophobic polymer layers positioned between structural elastomer layers.
PSA basal lamina that contains drug and/or enhancer.
Partial dissolution of drug and/or enhancer in the viscoelastic hydrophobic polymer and PSA.
No rate-controlling diffusion barrier in both structural elastomer layers (between hydrophobic layer and skin) and in the PSA layer itself.
Non-occlusive behavior with WVTR 11–18 g/m²-hr.
Enhancer chemistry anchored in propylene glycol monolaurate and/or dilaurate (and C8–C22 fatty portions for the broader class).
Specific polymer pairing embodiment includes:
- hydrophobic polymer: polyisobutene
- elastomer: polyurethane or polyether block amide
- PSA: polydimethylsiloxane

Implication for landscape mapping: The most relevant prior art and design-around targets are likely not “general transdermal diffusion patches,” but the intersection of (i) multilayer mechanical compliance, (ii) non-occlusive WVTR tuning, and (iii) the specific enhancer chemistry and its solubilization in hydrophobic polymers/PSAs, plus the numerical thickness/loading windows.

US patent landscape: likely key claim competitors and overlap zones

A full landscape requires bibliographic verification (assignees, filing dates, citations) that is not included in the prompt. Under that constraint, the best usable landscape analysis is to define where overlap would occur based on claim scope and typical transdermal design patterns.

1) Direct overlap zone: multilayer non-occlusive reservoir/matrix hybrid designs

Overlap most likely where prior patents claim:

multilaminate stacks using elastomeric layers for stretchable compliance,
hydrophobic interlayers to carry drug and enhancer,
a PSA layer on the skin-facing side,
explicit non-occlusive control via WVTR.

Why: Claim 1 and Claim 8–9 hard-wire WVTR behavior and diffusion barrier avoidance. A competitor that uses a single polymer matrix or a diffusion barrier membrane likely misses those structural/diffusion constraints.

2) Chemical overlap zone: propylene glycol mono-/dilaurate as solubility/permeation enhancer

The narrow enhancer set in Claims 13, 14, 18 is a high-likelihood overlap pivot. Competitors using different enhancers (e.g., alcohols, terpenes, surfactants outside the mono-/diester structure) can still land in Claim 1 only if the enhancer falls into the broader C2–C4 alkanediol ester/ether class of Claim 12, and if it is partially dissolved and arranged to avoid rate-controlling barriers.

3) Drug class overlap zone: estradiol and fentanyl analogs

Both drug classes are explicitly claimed (Claims 5–7, and quantified in Claim 18 and 19). Overlap risk rises for estradiol and fentanyl transdermal patch formulations that use similar laminated mechanics and non-occlusive WVTR.

4) Polymer embodiment overlap zone: polyisobutene + PDMS PSA + polyurethane/elastomer

Claim 17 and 20 form a tight material pairing. If a competitor’s patch uses:

polyisobutene as the hydrophobic viscoelastic interlayer,
PDMS-based PSA on skin,
polyurethane or PEBAX-like elastomer structural layers, and maintains similar thickness/loading, the overlap risk increases.

Scope for enforcement: what is “most valuable” in practice?

Most enforceable breadth

Claim 1 is the principal breadth: it covers at least one viscoelastic hydrophobic polymer lamina and a PSA lamina containing drug and/or enhancer, with elastomeric structural compliance layers, plus the diffusion-barrier avoidance language.
Claim 2 and Claim 3 extend with enhancer distribution and hydration via water vapor barrier provided by hydrophobic layers.

Most position-defining narrowing

Claims 8 and 9 (non-occlusive; WVTR 11–18 g/m²-hr) are likely decisive in distinguishing from common occlusive patches.
Claims 13–14, 18, 19 (propylene glycol mono-/dilaurate; explicit wt% ranges; explicit layer order; drug loading in PSA; enhancer loading in PSA and hydrophobic layers) are the primary “fallback” embodiment points that can survive broader prior art.

Design-around map (what competitors would change to avoid reading on)

This is derived directly from the claim scope constraints.

To reduce risk of Claim 1 / Claim 2 overlap

Avoid a viscoelastic hydrophobic polymer lamina positioned between structural elastomer laminas in the same diffusion relationship, or avoid the “partial dissolution” requirement in that hydrophobic polymer/PSA.
Ensure the PSA or structural elastomer acts as a rate-controlling barrier (opposite of the claim’s “no rate-controlling barrier” requirement).
Use a different enhancer class not captured by C2–C4 alkanediol fatty esters/ethers (C8–C22).

To reduce risk of Claim 8–9 non-occlusive overlap

Engineer WVTR outside 11–18 g/m²-hr or make the patch occlusive or semi-occlusive in a way inconsistent with Claim 8–9.

To reduce risk of Claims 13–14, 18, 19 narrow overlap

Replace propylene glycol monolaurate/dilaurate with non-matching enhancers or different chemical forms not encompassed by the monoester/diester propylene glycol restrictions.
Move drug and/or enhancer concentrations outside the claimed wt% windows for PSA and hydrophobic layers.

To reduce risk of Claims 17 and 20 embodiment overlap

Change the hydrophobic viscoelastic polymer away from polyisobutene, change the PSA away from polydimethylsiloxane, or change structural elastomer selection/thickness ranges away from 10–75 µm structural, 50–100 µm hydrophobic, 50–100 µm PSA.

Key Takeaways

US 5,006,342 claims a stretchable multilayer transdermal laminate where structural elastomer layers provide compliance and do not act as diffusion bottlenecks, while viscoelastic hydrophobic polymer and PSA layers contain and partially dissolve the drug and/or enhancer and also do not serve as rate-controlling diffusion barriers (Claim 1).
The claim set is anchored by non-occlusive performance with WVTR 11–18 g/m²-hr (Claims 8–9).
The highest-precision formulation scope centers on propylene glycol mono-/dilaurate as the enhancer, including explicit wt% ranges in PSA and hydrophobic layers (Claims 13–14, 18–19).
The narrowest embodiment pairs polyisobutene (hydrophobic layer) with PDMS PSA and polyurethane (or PEBAX-like) structural elastomers, with defined layer thickness (Claims 17, 20–21).

FAQs

Does Claim 1 require the drug to be in the PSA layer?
No. Claim 1 requires only that at least one of the viscoelastic hydrophobic polymer lamina(s) or the PSA lamina contains the drug.
Is the patch required to be non-occlusive?
Claims 8–9 require it is “not occlusive” and set a WVTR 11–18 g/m²-hr.
What is the core enhancer chemistry in the narrower claims?
Propylene glycol monolaurate and optionally propylene glycol dilaurate, with lauric fatty portion bounds implied by the stated C8–C22 framework.
What polymer pairing is singled out as an embodiment?
Polyisobutene as the hydrophobic viscoelastic polymer, polydimethylsiloxane as the PSA, and polyurethane or polyether block amide as the structural elastomer (Claims 17 and 20).
Which claims lock down layer order?
Claim 19 explicitly recites the device “in the following order” across structural elastomer, hydrophobic interlayers, and the PSA basal layer.

References

[1] US Patent 5,006,342, “Transdermal drug-delivery device” (claims provided in user prompt).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	119019	⤷ Start Trial
Austria	124256	⤷ Start Trial
Austria	87202	⤷ Start Trial
Australia	3853089	⤷ Start Trial
Australia	5784590	⤷ Start Trial
Australia	601528	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,006,342

Summary for Patent: 5,006,342