United States Patent 5,240,711 (Buprenorphine Transdermal System): Claim Scope, Core Limitations, and US Patent Landscape

US 5,240,711 covers a buprenorphine transdermal therapeutic system built around an impermeable backing layer and a pressure-sensitive adhesive (PSA) reservoir layer where buprenorphine is formulated with (i) a polymeric matrix, (ii) a specified range of a softening agent, and (iii) a specified range of a specific class of solvents for buprenorphine (including solvents with acidic groups and monoesters of dicarboxylic acids). Independent claim 1 is the center of gravity; dependent claims narrow to specific backing materials (including aluminum foil), specific polymer classes, specific softeners (e.g., dodecanol), and specific solvents (e.g., monomethyl glutarate and monomethyl adipate), including specific exemplified compositions.

Featured scope summary (claim 1):
A buprenorphine transdermal patch with:

impermeable backing;
PSA reservoir layer;
reservoir layer weight ranges:
- polymeric matrix 20–90%
- softening agent 0.1–30%
- buprenorphine base or pharmaceutically acceptable salt 0.1–20%
- solvent for buprenorphine or salt 0.1–30%
optional removable protective layer.

Key legal risk drivers:

“Solvent for buprenorphine” is a claim anchor with chemistry limitations (including solvents with acidic groups and monoesters of dicarboxylic acids).
“Reservoir layer” and “PSA reservoir layer” tie infringement analysis to patch construction and adhesive-reservoir formulation.
Dependent claims add further narrowing elements (polymer class, softener class, solvent instance), which can be used for both claim construction and design-around planning depending on whether equivalents are argued.

What does US 5,240,711 claim protect for buprenorphine transdermal patches?

Direct protection focus: the physical architecture (backing + PSA reservoir) and formulation ranges that enable buprenorphine delivery through the skin while constraining drug mobility within an adhesive reservoir.

What are the core components in claim 1?

Claim 1 requires all of the following structural elements:

Transdermal therapeutic system for administration of buprenorphine to the skin.
Backing layer that is impermeable to buprenorphine (and/or its salt).
Pressure-sensitive adhesive reservoir layer that contains:
- polymeric matrix (20–90% by weight)
- softening agent (0.1–30%)
- buprenorphine base or pharmaceutically acceptable salt (0.1–20%)
- solvent for buprenorphine or salt (0.1–30%)
Optional removable protective layer.

How broad is the “polymeric matrix” requirement?

Claim 1 is broad in category but bounded by “polymeric matrix” weight range (20–90%) and by functional placement in the reservoir layer. Dependent claim 5 narrows the polymeric matrix to:

rubber; rubber-like synthetic homo-, co- or block polymer; urethane; silicone.

Claim 13 separately references that the PSA reservoir layer comprises a polymer based on acrylates/methacrylates (or combinations). That is a different dependent limitation that impacts formulation mapping: it indicates the invention has both elastomeric-style and acrylic PSA embodiments, or that acrylic PSA is within the claimed PSA reservoir architecture.

How broad is the “solvent” concept in claim 1?

Claim 1 requires a “solvent for the buprenorphine or salt thereof” in 0.1–30% by weight. Dependent claims provide chemistry constraining examples/classes:

claim 7: solvent is monoester of a dicarboxylic acid
claim 8: solvent is monomethyl glutarate and/or monomethyl adipate
claim 15: solvent has at least one acidic group
claim 16 and 17: reservoir layer includes a solvent with at least one acidic group (and within specific formulation ranges)

This makes solvent selection one of the most actionable levers for infringement risk screening.

Which specific limitations in claim 1 create the highest infringement risk?

Is “impermeable backing layer” an easy design-around?

Not typically. Claim 1’s “impermeable to the active substance” is functional language. Most transdermal patch backs used to prevent drug loss can be characterized as impermeable to the API. If a competitor designs a different barrier strategy (e.g., multilayer membranes with varying permeability), the risk analysis becomes claim-construction dependent on permeability standards and evidence.

Is the “pressure-sensitive adhesive reservoir layer” required as-written?

Yes. Claim 1 ties reservoir function to a PSA reservoir layer. A system with a non-PSA matrix could avoid the literal “pressure-sensitive adhesive reservoir layer” requirement, but the feasibility depends on whether the system still uses a PSA in practice or whether equivalents would be asserted.

Do weight ranges bound “substantially” and “about” formulations?

Claim 1 provides explicit ranges (20–90% polymeric matrix, 0.1–30% softener, 0.1–20% buprenorphine, 0.1–30% solvent). Dependent claim 10 adds an “about” example:

polymer ~55%
buprenorphine ~10%
solvent ~10%
softener ~15%

In practice, competitors commonly land near or within these ranges. Even small deviations can matter for literal infringement, but equivalence may still be argued depending on the jurisdiction and record.

Does dependent claim specificity narrow the invention or provide alternative embodiments?

Dependent claims create additional “routes” into coverage. If a competitor matches claim 1 architecture but not the solvent class, they may still be vulnerable under equivalents; if they match claim 1 but not a dependent solvent embodiment, literal coverage might be avoided but the claim 1 “solvent” language remains broad until construed narrowly by the intrinsic record.

Which dependent claims narrow backing material, polymer class, softeners, and solvents?

Backing layer: aluminum foil and flexible/inflexible embodiments

Claim 2: backing is composed of a flexible material
Claim 3: backing is composed of an inflexible material
Claim 4: backing layer is aluminum foil

If an accused product uses a foil barrier layer, claim 4 becomes a strong literal match. If it uses a laminate membrane, claim 4 may not apply, but claim 1’s impermeable backing remains.

Polymeric matrix: rubber/urethane/silicone

Claim 5: polymeric matrix at least one of: rubber; rubber-like synthetic homo-, co- or block polymer; urethane; silicone.

Softening agents: specific alcohol/ester types

Claim 6: softening agent at least one of: dodecanol, undecanol, octanol, glycol, glycanol.
Claim 18: softening agent is an ester of a carboxylic acid.
Claim 14: softening ester is medium-chain triglyceride of caprylic/capric acids of coconut oil.

Solvent classes: dicarboxylic monoesters and acidic-group solvents

Claim 7: solvent is monoester of a dicarboxylic acid.
Claim 8: solvent is monomethyl glutarate and/or monomethyl adipate.
Claim 11: solvent present in about 25 to 100% of the weight of buprenorphine (a ratio limitation rather than absolute %).
Claim 15: solvent has at least one acidic group.

Specific exemplified composition

Claim 9: polymer is a copolymer of 2-ethylhexyl acrylate, vinyl acetate, and acrylic acid; softener is dodecanol; solvent is monomethyl glutarate.
Claim 10: example approximate percentages: polymer ~55%, buprenorphine ~10%, solvent ~10%, softener ~15%.

PSA polymer type

Claim 13: PSA reservoir layer comprises polymer based on acrylate, methacrylate, or combination.

Composite claims with skin area and dosing rate

Claim 16: laminated composite with (a) substantially impermeable polymer backing layer and (b) reservoir layer with:
- acrylate PSA
- 0.1–20% buprenorphine
- 0.1–30% ester softening agent
- 0.1–30% solvent for buprenorphine with at least one acidic group.
Claim 17: similar to claim 16 plus:
- skin contact area 16 cm²
- administration rate about 40 μg/hr

Claim 17 is narrow on performance geometry (area) and dosing rate, which can be a key differentiator if an accused product has different patch area/delivery rate.

How do claims 16 and 17 expand protection beyond claim 1?

Claim 16 adds:

explicit use of an acrylate PSA reservoir layer (not just “PSA reservoir layer” generally)
reservoir softening agent as an “ester of a carboxylic acid”
solvent must have at least one acidic group

That is tighter than claim 1 and aligns infringement analysis with a particular formulation subset. It can be useful for proving infringement when the competitor’s solvent and softener map cleanly to acidic-group solvents and ester softeners.

Claim 17 further constrains to:

patch size: 16 cm² skin contact area
delivery rate: about 40 μg/hr

If a competitor’s marketed system uses a different patch size and/or has a different measured in vivo delivery rate, claim 17 may not be implicated, but claims 16 and 1 remain in play.

What is the practical claim scope for “solvent with acidic groups”?

A key interpretation question is whether “solvent for buprenorphine” is limited to solvents that function as solubilizers/transport enhancers in the claimed ranges, or whether it is limited to the enumerated classes in dependent claims (dicarboxylic monoesters / acidic group solvents).

Under typical pharmaceutical claim construction approaches, dependent claims do not restrict claim 1 unless the patentee disclaimed broader coverage in the specification or used explicit “consisting of” style limiting language. Here, claim 1 is broad by name (solvent for buprenorphine), while dependent claims provide chemistry examples (monoesters, acidic group solvents) that can influence construction of what qualifies as “solvent” for infringement.

For product design, the safest posture is avoiding:

monoester of dicarboxylic acids (e.g., monomethyl glutarate, monomethyl adipate),
acidic-group solvent systems that match dependent claim 15/16 language,
maintaining the same solvent role in the PSA reservoir.

How does US 5,240,711 likely fit into the broader buprenorphine transdermal patent landscape?

Landscape pattern (market-typical): US buprenorphine transdermal portfolios historically include:

patch structural IP: backing, PSA reservoir, impermeability, multilayer laminates
formulation IP: polymer matrix, softeners, solvents/transporters
process IP: manufacturing steps for layering, casting, coating, and lamination
dosing/regimen IP: dosing amounts, patch size, delivery rate, and use instructions

US 5,240,711’s strongest hook is formulation-and-structure in one claim framework, with explicit percentage ranges and named chemical classes.

Where it typically sits relative to later competitors

Generic and “follow-on” buprenorphine patches usually face formulation-matching challenges (PSA reservoir composition and solvent/softener chemistry) plus patch geometry/delivery rate requirements.
Alternative buprenorphine delivery systems (e.g., different adhesive matrices, different backing materials, different solvent systems) can reduce literal overlap, but may still risk equivalence-based assertions if overall barrier + PSA + reservoir composition performs similarly.

What other US patent types would commonly surround it?

Even if not enumerated here, the surrounding portfolio often includes:

patents on “bioavailability enhancing” or permeation-enhancing excipients, including fatty alcohols, esters, and acidic-functional solvents,
patents on acrylate/methacrylate PSA formulations,
patents on patch design and packaging (release liner, lamination, pouching),
patents on delivery rate control, including patch size and loading.

The claim’s internal split between elastomeric polymer matrix (claim 5) and acrylic PSA reservoirs (claim 13, 16) suggests the foundational inventive concept was not restricted to a single PSA backbone family, which increases the chance that later embodiments encountered this claim.

When does US 5,240,711 lose exclusivity (expiration and term)?

A complete exclusivity timeline requires the patent’s filing date, issue date, and any term adjustments, plus any PTA/terminal disclaimer data. This information is not provided in the prompt and cannot be reconstructed reliably here. Without those inputs, an expiration-date statement would be incomplete and potentially inaccurate.

What is the most realistic generic entry risk if someone tries to copy this claim scope?

Highest-risk copying behaviors:

using a PSA reservoir patch with a backing barrier that is impermeable to buprenorphine;
using a reservoir polymeric matrix in the 20–90% range;
using a softener in the 0.1–30% range drawn from the claimed alcohol/ester/coconut MCT categories;
using a buprenorphine loading and solvent loading within the 0.1–30% ranges;
especially, using a monoester of a dicarboxylic acid or a solvent with an acidic group as the solvent.

Lower-risk designs (relative, not absolute):

switch the reservoir away from a PSA reservoir layer (if feasible while maintaining delivery);
materially change solvent chemistry away from monoesters of dicarboxylic acids and away from acidic-group solvent systems;
change patch geometry and delivery rate away from the claim 17 “16 cm² / ~40 μg/hr” target (to avoid that narrow performance claim).

How strong is the patent estate for this asset based on claim drafting?

On claim language alone, US 5,240,711 is stronger than a purely “method” claim because it captures a commercial product configuration. The use of:

explicit component roles (backing impermeable; PSA reservoir),
explicit percentage ranges,
chemistry-limited dependent claims, creates a structured infringement map that can be targeted by product testing and formulation analysis.

At the same time, the scope is not “anything goes” for solvents and softeners, because dependent claims create a well-defined chemical neighborhood. For litigation, that tends to sharpen the evidentiary focus: solvent identity and acidic functionality; softener identity; polymer type; reservoir architecture; and patch dosing geometry for claim 17.

Key Takeaways

US 5,240,711 centers on a buprenorphine transdermal patch with an impermeable backing and a PSA reservoir layer containing specified weight ranges of polymeric matrix, softener, buprenorphine, and solvent.
The most litigation-relevant elements are the solvent for buprenorphine and its chemistry constraints (acidic-group solvents and monoesters of dicarboxylic acids) plus the softening agent class.
Dependent claims create narrow “snapshots” into coverage, including aluminum foil backing (claim 4), specific polymer categories (claim 5), specific softeners (claims 6 and 18), and specific solvents like monomethyl glutarate/adipate (claims 8, 9, 15).
Claim 17 adds patch-level performance limits (16 cm² and ~40 μg/hr), making product-specific dosing geometry a key differentiator for infringement risk.

FAQs

What formulation changes most effectively reduce literal overlap with US 5,240,711 claim 1?
Substituting away from the claimed “solvent for buprenorphine” chemistry (especially acidic-group and dicarboxylic monoester solvents) and changing softener identity outside the specified categories reduce claim mapping.
Do acrylate PSA patches fall within the patent, or is it limited to elastomeric matrices?
Dependent claims 13 and 16 expressly cover acrylate/methacrylate PSA reservoir polymers, so acrylic PSA embodiments are within scope.
How important is patch size and delivery rate for infringement under US 5,240,711?
Patch size/delivery rate are directly tied only to the narrow composite performance claim 17; claim 1 is not limited to a specific area or delivery rate.
If a competitor avoids monomethyl glutarate but uses a different acidic solvent, does that escape?
A change that removes acidic-group functionality can help; switching within acidic-group solvent systems likely keeps material elements aligned to claim 15/16 concepts.
Is aluminum-foil backing a necessary feature to infringe?
No. Aluminum foil is only required for dependent claim 4. Claim 1 requires only a backing that is impermeable to buprenorphine.

References (APA)

United States Patent 5,240,711. (n.d.). “Transdermal therapeutic systems for the administration of buprenorphine.”

Title:	Transdermal therapeutic system comprising as active component buprenorphine
Abstract:	The controlled release of buprenorphine or the pharmaceutically acceptable salts thereof to the skin over a period of time of at least 24 hours is ensured by a transdermal therapeutic system consisting of a backing layer which is impermeable to the active substance, a pressure-sensitive adhesive reservoir layer, and optionally a removable protective layer. Said reservoir layer of said system comprises 20 to 90%-wt polymeric material, 0.1 to 30%-wt softener, 0.1 to 20%-wt buprenorphine base or one of the pharmaceutically acceptable salts thereof, and 0.1 to 30%-wt solvent for the active substance base.
Inventor(s):	Thomas Hille, Lothar Deurer, Hans-Rainer Hoffmann
Assignee:	Purdue Pharma LP
Application Number:	US07/951,030
Patent Claim Types: see list of patent claims	Compound;
Patent landscape, scope, and claims:	United States Patent 5,240,711 (Buprenorphine Transdermal System): Claim Scope, Core Limitations, and US Patent Landscape US 5,240,711 covers a buprenorphine transdermal therapeutic system built around an impermeable backing layer and a pressure-sensitive adhesive (PSA) reservoir layer where buprenorphine is formulated with (i) a polymeric matrix, (ii) a specified range of a softening agent, and (iii) a specified range of a specific class of solvents for buprenorphine (including solvents with acidic groups and monoesters of dicarboxylic acids). Independent claim 1 is the center of gravity; dependent claims narrow to specific backing materials (including aluminum foil), specific polymer classes, specific softeners (e.g., dodecanol), and specific solvents (e.g., monomethyl glutarate and monomethyl adipate), including specific exemplified compositions. Featured scope summary (claim 1): A buprenorphine transdermal patch with: impermeable backing; PSA reservoir layer; reservoir layer weight ranges: polymeric matrix 20–90% softening agent 0.1–30% buprenorphine base or pharmaceutically acceptable salt 0.1–20% solvent for buprenorphine or salt 0.1–30% optional removable protective layer. Key legal risk drivers: “Solvent for buprenorphine” is a claim anchor with chemistry limitations (including solvents with acidic groups and monoesters of dicarboxylic acids). “Reservoir layer” and “PSA reservoir layer” tie infringement analysis to patch construction and adhesive-reservoir formulation. Dependent claims add further narrowing elements (polymer class, softener class, solvent instance), which can be used for both claim construction and design-around planning depending on whether equivalents are argued. What does US 5,240,711 claim protect for buprenorphine transdermal patches? Direct protection focus: the physical architecture (backing + PSA reservoir) and formulation ranges that enable buprenorphine delivery through the skin while constraining drug mobility within an adhesive reservoir. What are the core components in claim 1? Claim 1 requires all of the following structural elements: Transdermal therapeutic system for administration of buprenorphine to the skin. Backing layer that is impermeable to buprenorphine (and/or its salt). Pressure-sensitive adhesive reservoir layer that contains: polymeric matrix (20–90% by weight) softening agent (0.1–30%) buprenorphine base or pharmaceutically acceptable salt (0.1–20%) solvent for buprenorphine or salt (0.1–30%) Optional removable protective layer. How broad is the “polymeric matrix” requirement? Claim 1 is broad in category but bounded by “polymeric matrix” weight range (20–90%) and by functional placement in the reservoir layer. Dependent claim 5 narrows the polymeric matrix to: rubber; rubber-like synthetic homo-, co- or block polymer; urethane; silicone. Claim 13 separately references that the PSA reservoir layer comprises a polymer based on acrylates/methacrylates (or combinations). That is a different dependent limitation that impacts formulation mapping: it indicates the invention has both elastomeric-style and acrylic PSA embodiments, or that acrylic PSA is within the claimed PSA reservoir architecture. How broad is the “solvent” concept in claim 1? Claim 1 requires a “solvent for the buprenorphine or salt thereof” in 0.1–30% by weight. Dependent claims provide chemistry constraining examples/classes: claim 7: solvent is monoester of a dicarboxylic acid claim 8: solvent is monomethyl glutarate and/or monomethyl adipate claim 15: solvent has at least one acidic group claim 16 and 17: reservoir layer includes a solvent with at least one acidic group (and within specific formulation ranges) This makes solvent selection one of the most actionable levers for infringement risk screening. Which specific limitations in claim 1 create the highest infringement risk? Is “impermeable backing layer” an easy design-around? Not typically. Claim 1’s “impermeable to the active substance” is functional language. Most transdermal patch backs used to prevent drug loss can be characterized as impermeable to the API. If a competitor designs a different barrier strategy (e.g., multilayer membranes with varying permeability), the risk analysis becomes claim-construction dependent on permeability standards and evidence. Is the “pressure-sensitive adhesive reservoir layer” required as-written? Yes. Claim 1 ties reservoir function to a PSA reservoir layer. A system with a non-PSA matrix could avoid the literal “pressure-sensitive adhesive reservoir layer” requirement, but the feasibility depends on whether the system still uses a PSA in practice or whether equivalents would be asserted. Do weight ranges bound “substantially” and “about” formulations? Claim 1 provides explicit ranges (20–90% polymeric matrix, 0.1–30% softener, 0.1–20% buprenorphine, 0.1–30% solvent). Dependent claim 10 adds an “about” example: polymer ~55% buprenorphine ~10% solvent ~10% softener ~15% In practice, competitors commonly land near or within these ranges. Even small deviations can matter for literal infringement, but equivalence may still be argued depending on the jurisdiction and record. Does dependent claim specificity narrow the invention or provide alternative embodiments? Dependent claims create additional “routes” into coverage. If a competitor matches claim 1 architecture but not the solvent class, they may still be vulnerable under equivalents; if they match claim 1 but not a dependent solvent embodiment, literal coverage might be avoided but the claim 1 “solvent” language remains broad until construed narrowly by the intrinsic record. Which dependent claims narrow backing material, polymer class, softeners, and solvents? Backing layer: aluminum foil and flexible/inflexible embodiments Claim 2: backing is composed of a flexible material Claim 3: backing is composed of an inflexible material Claim 4: backing layer is aluminum foil If an accused product uses a foil barrier layer, claim 4 becomes a strong literal match. If it uses a laminate membrane, claim 4 may not apply, but claim 1’s impermeable backing remains. Polymeric matrix: rubber/urethane/silicone Claim 5: polymeric matrix at least one of: rubber; rubber-like synthetic homo-, co- or block polymer; urethane; silicone. Softening agents: specific alcohol/ester types Claim 6: softening agent at least one of: dodecanol, undecanol, octanol, glycol, glycanol. Claim 18: softening agent is an ester of a carboxylic acid. Claim 14: softening ester is medium-chain triglyceride of caprylic/capric acids of coconut oil. Solvent classes: dicarboxylic monoesters and acidic-group solvents Claim 7: solvent is monoester of a dicarboxylic acid. Claim 8: solvent is monomethyl glutarate and/or monomethyl adipate. Claim 11: solvent present in about 25 to 100% of the weight of buprenorphine (a ratio limitation rather than absolute %). Claim 15: solvent has at least one acidic group. Specific exemplified composition Claim 9: polymer is a copolymer of 2-ethylhexyl acrylate, vinyl acetate, and acrylic acid; softener is dodecanol; solvent is monomethyl glutarate. Claim 10: example approximate percentages: polymer ~55%, buprenorphine ~10%, solvent ~10%, softener ~15%. PSA polymer type Claim 13: PSA reservoir layer comprises polymer based on acrylate, methacrylate, or combination. Composite claims with skin area and dosing rate Claim 16: laminated composite with (a) substantially impermeable polymer backing layer and (b) reservoir layer with: acrylate PSA 0.1–20% buprenorphine 0.1–30% ester softening agent 0.1–30% solvent for buprenorphine with at least one acidic group. Claim 17: similar to claim 16 plus: skin contact area 16 cm² administration rate about 40 μg/hr Claim 17 is narrow on performance geometry (area) and dosing rate, which can be a key differentiator if an accused product has different patch area/delivery rate. How do claims 16 and 17 expand protection beyond claim 1? Claim 16 adds: explicit use of an acrylate PSA reservoir layer (not just “PSA reservoir layer” generally) reservoir softening agent as an “ester of a carboxylic acid” solvent must have at least one acidic group That is tighter than claim 1 and aligns infringement analysis with a particular formulation subset. It can be useful for proving infringement when the competitor’s solvent and softener map cleanly to acidic-group solvents and ester softeners. Claim 17 further constrains to: patch size: 16 cm² skin contact area delivery rate: about 40 μg/hr If a competitor’s marketed system uses a different patch size and/or has a different measured in vivo delivery rate, claim 17 may not be implicated, but claims 16 and 1 remain in play. What is the practical claim scope for “solvent with acidic groups”? A key interpretation question is whether “solvent for buprenorphine” is limited to solvents that function as solubilizers/transport enhancers in the claimed ranges, or whether it is limited to the enumerated classes in dependent claims (dicarboxylic monoesters / acidic group solvents). Under typical pharmaceutical claim construction approaches, dependent claims do not restrict claim 1 unless the patentee disclaimed broader coverage in the specification or used explicit “consisting of” style limiting language. Here, claim 1 is broad by name (solvent for buprenorphine), while dependent claims provide chemistry examples (monoesters, acidic group solvents) that can influence construction of what qualifies as “solvent” for infringement. For product design, the safest posture is avoiding: monoester of dicarboxylic acids (e.g., monomethyl glutarate, monomethyl adipate), acidic-group solvent systems that match dependent claim 15/16 language, maintaining the same solvent role in the PSA reservoir. How does US 5,240,711 likely fit into the broader buprenorphine transdermal patent landscape? Landscape pattern (market-typical): US buprenorphine transdermal portfolios historically include: patch structural IP: backing, PSA reservoir, impermeability, multilayer laminates formulation IP: polymer matrix, softeners, solvents/transporters process IP: manufacturing steps for layering, casting, coating, and lamination dosing/regimen IP: dosing amounts, patch size, delivery rate, and use instructions US 5,240,711’s strongest hook is formulation-and-structure in one claim framework, with explicit percentage ranges and named chemical classes. Where it typically sits relative to later competitors Generic and “follow-on” buprenorphine patches usually face formulation-matching challenges (PSA reservoir composition and solvent/softener chemistry) plus patch geometry/delivery rate requirements. Alternative buprenorphine delivery systems (e.g., different adhesive matrices, different backing materials, different solvent systems) can reduce literal overlap, but may still risk equivalence-based assertions if overall barrier + PSA + reservoir composition performs similarly. What other US patent types would commonly surround it? Even if not enumerated here, the surrounding portfolio often includes: patents on “bioavailability enhancing” or permeation-enhancing excipients, including fatty alcohols, esters, and acidic-functional solvents, patents on acrylate/methacrylate PSA formulations, patents on patch design and packaging (release liner, lamination, pouching), patents on delivery rate control, including patch size and loading. The claim’s internal split between elastomeric polymer matrix (claim 5) and acrylic PSA reservoirs (claim 13, 16) suggests the foundational inventive concept was not restricted to a single PSA backbone family, which increases the chance that later embodiments encountered this claim. When does US 5,240,711 lose exclusivity (expiration and term)? A complete exclusivity timeline requires the patent’s filing date, issue date, and any term adjustments, plus any PTA/terminal disclaimer data. This information is not provided in the prompt and cannot be reconstructed reliably here. Without those inputs, an expiration-date statement would be incomplete and potentially inaccurate. What is the most realistic generic entry risk if someone tries to copy this claim scope? Highest-risk copying behaviors: using a PSA reservoir patch with a backing barrier that is impermeable to buprenorphine; using a reservoir polymeric matrix in the 20–90% range; using a softener in the 0.1–30% range drawn from the claimed alcohol/ester/coconut MCT categories; using a buprenorphine loading and solvent loading within the 0.1–30% ranges; especially, using a monoester of a dicarboxylic acid or a solvent with an acidic group as the solvent. Lower-risk designs (relative, not absolute): switch the reservoir away from a PSA reservoir layer (if feasible while maintaining delivery); materially change solvent chemistry away from monoesters of dicarboxylic acids and away from acidic-group solvent systems; change patch geometry and delivery rate away from the claim 17 “16 cm² / ~40 μg/hr” target (to avoid that narrow performance claim). How strong is the patent estate for this asset based on claim drafting? On claim language alone, US 5,240,711 is stronger than a purely “method” claim because it captures a commercial product configuration. The use of: explicit component roles (backing impermeable; PSA reservoir), explicit percentage ranges, chemistry-limited dependent claims, creates a structured infringement map that can be targeted by product testing and formulation analysis. At the same time, the scope is not “anything goes” for solvents and softeners, because dependent claims create a well-defined chemical neighborhood. For litigation, that tends to sharpen the evidentiary focus: solvent identity and acidic functionality; softener identity; polymer type; reservoir architecture; and patch dosing geometry for claim 17. Key Takeaways US 5,240,711 centers on a buprenorphine transdermal patch with an impermeable backing and a PSA reservoir layer containing specified weight ranges of polymeric matrix, softener, buprenorphine, and solvent. The most litigation-relevant elements are the solvent for buprenorphine and its chemistry constraints (acidic-group solvents and monoesters of dicarboxylic acids) plus the softening agent class. Dependent claims create narrow “snapshots” into coverage, including aluminum foil backing (claim 4), specific polymer categories (claim 5), specific softeners (claims 6 and 18), and specific solvents like monomethyl glutarate/adipate (claims 8, 9, 15). Claim 17 adds patch-level performance limits (16 cm² and ~40 μg/hr), making product-specific dosing geometry a key differentiator for infringement risk. FAQs What formulation changes most effectively reduce literal overlap with US 5,240,711 claim 1? Substituting away from the claimed “solvent for buprenorphine” chemistry (especially acidic-group and dicarboxylic monoester solvents) and changing softener identity outside the specified categories reduce claim mapping. Do acrylate PSA patches fall within the patent, or is it limited to elastomeric matrices? Dependent claims 13 and 16 expressly cover acrylate/methacrylate PSA reservoir polymers, so acrylic PSA embodiments are within scope. How important is patch size and delivery rate for infringement under US 5,240,711? Patch size/delivery rate are directly tied only to the narrow composite performance claim 17; claim 1 is not limited to a specific area or delivery rate. If a competitor avoids monomethyl glutarate but uses a different acidic solvent, does that escape? A change that removes acidic-group functionality can help; switching within acidic-group solvent systems likely keeps material elements aligned to claim 15/16 concepts. Is aluminum-foil backing a necessary feature to infringe? No. Aluminum foil is only required for dependent claim 4. Claim 1 requires only a backing that is impermeable to buprenorphine. References (APA) United States Patent 5,240,711. (n.d.). “Transdermal therapeutic systems for the administration of buprenorphine.” More… ↓ ⤷ Start Trial

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Germany	3939376	Nov 29, 1989

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	135205	⤷ Start Trial
Australia	632182	⤷ Start Trial
Australia	6569990	⤷ Start Trial
Canada	2030178	⤷ Start Trial
Czechoslovakia	9005598	⤷ Start Trial
Czech Republic	282557	⤷ Start Trial
Germany	3939376	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,240,711

Summary for Patent: 5,240,711