Details for Patent: 8,747,888

Which drugs does patent 8,747,888 protect, and when does it expire?

Patent 8,747,888 protects TWIRLA and is included in one NDA.

This patent has nineteen patent family members in twelve countries.

Summary for Patent: 8,747,888

Title:	Dermal delivery device with in situ seal
Abstract:	This invention relates to a transdermal drug delivery device that comprises an active ingredient (AI) layer, having a skin contacting surface and a non-skin contacting surface and comprising a volatile component, a release liner impermeable to the volatile component adjacent the skin contacting surface of the AI layer having a perimeter that extends beyond the perimeter of the AI layer in all directions, and an overlay comprising a pressure sensitive adhesive (PSA) that does not absorb the volatile component adjacent the non-skin contacting surface of the Al layer having a perimeter of which extends beyond the perimeter of the AI layer in all directions, wherein the release liner and the PSA of the overlay are in contact with and adhered to each other around the perimeter of the AI layer to form a seal that reduces or prevents volatile component loss.
Inventor(s):	Agis Kydonieus, Robert G. Conway, Thomas M. Rossi
Assignee:	Agile Therapeutics Inc
Application Number:	US13/553,362
Patent Claim Types: see list of patent claims	Use; Compound; Delivery; Device;

US Patent 8,747,888: Claim Scope, Patent Expiration, Litigation Risk and Transdermal Patch Landscape

US Patent 8,747,888 protects a specific non-heat-sealed transdermal patch architecture. Its core combination is a polyacrylate drug-in-adhesive layer containing ethyl lactate and/or DMSO, a PIB-based perimeter-sealing overlay, an internal backing layer, and a release liner that extends beyond the drug layer. The patent is most relevant to levonorgestrel/ethinyl estradiol patches, although claim 1 is not limited to contraceptive drugs.

The principal infringement risk is structural. A competing patch must avoid at least one required element of claim 1, such as the PIB overlay adhesive, the comparative volatile-component solubility limitation, the extended perimeter PSA seal, or the absence of heat sealing.

What does US Patent 8,747,888 protect?

US Patent 8,747,888, issued June 10, 2014, protects a transdermal delivery device rather than a drug molecule, treatment method, or manufacturing process. The patent centers on the interaction between the drug-containing adhesive layer and a separate overlay that seals the patch perimeter.

Claim 1 requires all of the following:

Required element	Scope of limitation
Drug-in-adhesive layer	Polymer matrix containing an active ingredient, PSA and a volatile component
Volatile component	Ethyl lactate, DMSO or both
Drug-layer PSA	Polyacrylate PSA
Release liner	In direct contact with the skin-facing surface
Perimeter geometry	Release liner extends beyond the drug layer in all directions
Overlay	Located on the non-skin-facing side and extends beyond the drug layer in all directions
Overlay PSA	PIB PSA
Internal backing	Located between the drug layer and overlay
Perimeter seal	Overlay PSA directly contacts and adheres to the release liner around the drug-layer perimeter
Intermediate layer	Positioned between overlay PSA and overlay covering
PSA-flow barrier	Intermediate layer prevents overlay PSA from flowing into the overlay covering
Solubility relationship	Volatile-component solubility is lower in the overlay PIB PSA than in the drug-layer PSA
Manufacturing characteristic	Adhesion of the drug layer is achieved without heat sealing

A patch that lacks any one of these limitations would generally fall outside literal infringement of claim 1, subject to claim construction and possible doctrine-of-equivalents issues.

How broad is independent claim 1?

Claim 1 is broad as to the active ingredient but narrow as to patch construction and adhesive chemistry.

Broad elements

The claim does not require:

• Levonorgestrel;
• Ethinyl estradiol;
• A contraceptive indication;
• A specific drug concentration;
• A specific patch size;
• A specific release rate;
• A specific overlay-covering material;
• A specific amount of DMSO or ethyl lactate;
• A particular treatment regimen.

The active ingredient can therefore be a drug other than levonorgestrel, provided that the remaining structural and chemical limitations are met.

Narrow elements

The claim requires a particular division of function:

1. The polyacrylate PSA carries the active ingredient and dissolves at least part of the volatile component.
2. The PIB overlay PSA creates the perimeter seal.
3. The intermediate polymeric layer prevents the PIB adhesive from flowing into the outer covering.
4. The volatile component has lower solubility in the PIB overlay PSA than in the drug-layer PSA.
5. The patch is assembled without heat sealing the drug-layer adhesion interface.

This combination distinguishes the patent from a conventional single-layer drug-in-adhesive patch, a patch with a heat-sealed perimeter, and a patch using the same adhesive chemistry in both the drug layer and the overlay.

What formulations are protected by US 8,747,888?

The dependent claims identify several protected formulation and materials combinations.

Drug-layer polyacrylate adhesive

Claims 2, 13 and 20 require a polyacrylate adhesive copolymer containing:

• 2-ethylhexyl acrylate as a monomer; and
• 50% to 60% vinyl acetate as a comonomer.

Because claims 2 and 13 are substantively duplicative, they do not materially expand the technical scope beyond the specified copolymer composition.

PIB overlay adhesive

Claims 14 and 21 require a PIB PSA containing the following ranges:

Component	Claimed range
Crospovidone	5% to 45% by weight
Low-viscosity PIB	10% to 60%
High-viscosity PIB	2% to 15%
Polybutene	10% to 60%
Mineral oil	0% to 20%

The claims do not state that every listed component must be present because mineral oil has a zero lower bound. A competing formulation could target a non-PIB overlay adhesive, alter the composition outside the claimed ranges, or use a different perimeter-sealing mechanism.

Release liner

Claims 3, 4, 16 and 22 cover release liners made from:

• Fluorinated polymer film;
• Siliconized polymer film;
• Foil lined with a fluorinated or siliconized polymer; and
• Fluorinated or siliconized polyester film.

The release liner is not merely a packaging component in these claims. It participates in the perimeter seal because the overlay PSA must directly contact and adhere to it around the drug-layer perimeter.

Overlay covering

Claims 5, 10, 11, 18 and 22 cover an overlay covering that is non-tacky, flexible and moisture permeable. Listed materials include:

• Polyurethane film, foam or spunbonded structures;
• Polyolefin foam;
• Woven or non-woven fabric; and
• Polyester fabric.

The moisture-permeability limitation can be important in freedom-to-operate analysis. A multilayer covering that is occlusive or lacks the claimed flexibility may avoid dependent claims, although it would not necessarily avoid claim 1.

Intermediate layer

Claims 6 through 9 and 17 through 22 cover an intermediate layer that adheres to both the overlay PSA and the overlay covering. The listed materials include:

• Polyacrylate PSA;
• Polyurethane;
• Polyethylene/ethyl vinyl acetate copolymer;
• Rubber-based polymer; and
• Cross-linkable silicone rubber.

The intermediate layer must prevent the overlay PSA from flowing into the overlay covering. The claim therefore has both a material limitation and a functional limitation.

Which claims specifically cover levonorgestrel patches?

Claims 12 and 19 limit the active ingredient to levonorgestrel or levonorgestrel in combination with ethinyl estradiol.

Claim 12 is a direct dependent claim from claim 1. Claim 19 creates a narrower combination that incorporates the limitations of claims 15 through 18 and then specifies levonorgestrel or levonorgestrel/ethinyl estradiol.

The commercially important scope is therefore divided:

Claim group	Commercial relevance
Claim 1	Broad patch architecture, not limited to contraception
Claims 2 and 13	Specific drug-layer polyacrylate copolymer
Claims 3 and 4	Fluorinated or siliconized release liner
Claims 5 through 11	Overlay covering and intermediate-layer materials
Claim 12	Levonorgestrel or levonorgestrel/ethinyl estradiol
Claims 14 and 21	Specific PIB overlay formulation
Claims 15 through 20	Humectant, material and contraceptive combinations
Claim 22	Highly specific full-device configuration

How does claim 22 differ from claim 1?

Claim 22 is the narrowest and most technically specific claim. It requires a complete configuration with:

• Polyester internal backing film;
• Polyacrylate intermediate PSA;
• Polyester woven overlay fabric;
• Fluorinated polyester release liner;
• PVP or PVP/VA humectant;
• DMSO as the volatile component;
• The specified PIB composition ranges; and
• The specified 2-ethylhexyl acrylate/vinyl acetate polyacrylate copolymer.

Claim 22 is harder to read on a competing product because it requires simultaneous practice of multiple material selections. It may, however, be commercially significant if a marketed patch uses the same formulation and construction.

The hierarchy is straightforward:

• Claim 1 presents the principal broad combination.
• Claims 2 through 21 narrow individual components or combinations.
• Claim 22 claims a highly specific commercial-style embodiment.

What is the likely patent expiration date?

US patent term is generally 20 years from the earliest effective nonprovisional U.S. filing date, subject to patent-term adjustment, patent-term extension and terminal disclaimers. The grant date, June 10, 2014, does not determine expiration. [1]

For US 8,747,888, the relevant expiration analysis must account for:

• The earliest effective priority or nonprovisional filing date;
• Any continuation or divisional relationship;
• Patent-term adjustment shown on the patent record;
• Any terminal disclaimer; and
• Whether the patent received a regulatory patent-term extension.

The claims alone do not establish a legally operative expiration date. A commercial freedom-to-operate opinion should use the USPTO Patent Center record and the issued patent’s term information rather than calculate term solely from the grant date. [2]

What is the Orange Book status of US 8,747,888?

A patent’s inclusion in the FDA Orange Book is separate from issuance and enforceability. The patent must be assessed against the FDA’s patent-listing record for the relevant approved drug product. [3]

For a levonorgestrel/ethinyl estradiol transdermal product, the relevant questions are:

• Whether the patent is listed against the approved NDA;
• Whether the listing identifies the patent as covering the drug substance, drug product or method of use;
• Whether the patent has an unexpired listed claim;
• Whether the approved label falls within a listed method-of-use claim; and
• Whether the NDA holder submitted a current certification or delisting request.

The asserted claims are device and formulation claims. They are not method-of-use claims. Their Orange Book relevance would therefore depend on whether the FDA accepted them as covering the approved drug product under the applicable listing regulations. [4]

What Paragraph IV challenges could target this patent?

A Paragraph IV certification could challenge an Orange Book-listed patent by asserting that the patent is invalid, unenforceable or not infringed. [5]

For US 8,747,888, likely challenge theories would include:

Non-infringement

A generic or follow-on patch could avoid literal infringement by using:

• A heat-sealed perimeter;
• A non-PIB overlay adhesive;
• A drug-layer adhesive other than the claimed polyacrylate;
• A volatile component other than DMSO or ethyl lactate;
• A release liner that does not extend beyond the drug layer;
• An overlay that does not directly contact the release liner around the perimeter; or
• An intermediate layer that does not satisfy the PSA-flow-prevention limitation.

Invalidity

Potential validity challenges could focus on:

• Anticipation by an earlier transdermal patch disclosure;
• Obviousness based on combining drug-in-adhesive technology with PIB perimeter sealing;
• Enablement of the comparative solubility limitation;
• Written-description support for the full range of PIB compositions;
• Indefiniteness of “prevents flow” or “solubility”; and
• Support for the “without heat sealing” limitation.

The comparative solubility requirement is likely to generate technical dispute. It requires a comparison between the volatile component’s solubility in two different PSA environments. The assay conditions, temperature, polymer grades, loading level and equilibrium methodology could materially affect the result.

How strong is the patent estate?

The patent appears strongest against products that reproduce the complete multilayer architecture, particularly a levonorgestrel/ethinyl estradiol patch with:

• A DMSO-containing polyacrylate drug layer;
• A PIB overlay adhesive;
• A fluorinated polyester release liner;
• A polyester internal backing film;
• A polyester fabric overlay; and
• The specified PIB composition.

Its strength is lower against products using materially different construction. The patent does not independently control levonorgestrel, ethinyl estradiol, DMSO, polyacrylate adhesives, PIB adhesives, or transdermal delivery as general technologies.

Strength factors

• Claim 1 combines structural, compositional and functional limitations.
• The claim covers the perimeter-sealing interface, not merely the patch’s broad appearance.
• Claims 12 and 19 directly target contraceptive embodiments.
• Claim 22 provides a detailed product configuration that may align closely with a commercial formulation.

Vulnerability factors

• The claim requires many simultaneous limitations.
• “Non-heat sealed” may create a significant design-around route.
• The relative-solubility limitation may be difficult to prove without controlled testing.
• The broad active-ingredient language may invite prior-art combinations.
• The dependent claims have substantial material specificity, which narrows enforcement scope.

What generic launch risks exist?

A conventional generic transdermal patch may not infringe if it uses a different adhesive architecture. The highest-risk launch scenario is a product designed to be pharmaceutically equivalent while duplicating the patented manufacturing and laminate structure.

Launch design	Risk under US 8,747,888
Same DMSO/polyacrylate drug layer and PIB perimeter overlay	High
Same materials but heat-sealed perimeter	Reduced literal-infringement risk
Non-PIB overlay adhesive	Reduced risk
No extended release liner or overlay perimeter	Reduced risk
Different volatile component	Potentially outside claim 1
Same active ingredients in a conventional single-layer patch	Lower risk under this patent
Same full configuration as claim 22	Highest risk

A generic sponsor would normally need product-by-product testing, adhesive-composition analysis and laminate cross-section analysis. Label review alone would not resolve infringement because the claims are directed primarily to physical construction and formulation.

What manufacturing and IP barriers matter?

The patent’s manufacturing significance is tied to avoiding heat sealing while maintaining perimeter integrity. That may reduce thermal exposure to volatile solvents, adhesives and active ingredients. It also creates a specific assembly requirement: the overlay PSA must bond to the release liner around the drug layer without relying on a heat-sealed closure.

Relevant manufacturing controls include:

• PSA coating and drying conditions;
• DMSO or ethyl lactate retention;
• Adhesive compatibility;
• Overlay PSA viscosity;
• Intermediate-layer integrity;
• Perimeter dimensions;
• Release-liner overhang;
• Lamination pressure and temperature;
• PSA migration into the overlay covering; and
• Seal strength over shelf life.

These production parameters can create evidence relevant to infringement even where the public product label does not disclose the details.

What is the competitive landscape for levonorgestrel transdermal patches?

Levonorgestrel and ethinyl estradiol are long-established active ingredients. Their active-ingredient patent barriers are generally distinct from the delivery-system protection claimed in US 8,747,888.

The competitive barriers are more likely to arise from:

• Patch formulation patents;
• Adhesive and solvent systems;
• Laminate and overlay construction;
• Manufacturing know-how;
• Regulatory equivalence requirements;
• Device performance specifications; and
• Orange Book-listed product patents associated with an approved NDA.

A competitor can use the same active ingredients without necessarily practicing this patent. Conversely, a product can create infringement risk through its adhesive and laminate design even if it uses a different commercial name or dosage schedule.

What litigation and settlement issues should be monitored?

The patent number alone does not establish a filed Paragraph IV case, settlement agreement or current enforcement action. The relevant monitoring sources are:

1. FDA Orange Book patent and exclusivity records.
2. FDA paragraph IV notification and NDA records.
3. USPTO Patent Center prosecution and maintenance records.
4. Federal district court dockets.
5. Federal Circuit opinions.
6. Assignment and licensing records.
7. Approved product labeling and regulatory submissions.

A settlement involving a related transdermal contraceptive patent would not automatically resolve rights under US 8,747,888. Each patent, claim set and launch date must be analyzed separately.

Key Takeaways

• US 8,747,888 is a device and formulation patent, not an active-ingredient patent.
• Claim 1 requires a polyacrylate drug layer, DMSO or ethyl lactate, a PIB overlay PSA, an extended perimeter seal, an intermediate flow-barrier layer and non-heat-sealed adhesion.
• Claims 12 and 19 specifically cover levonorgestrel and levonorgestrel/ethinyl estradiol embodiments.
• Claim 22 is a narrow full-device combination involving DMSO, PVP or PVP/VA, fluorinated polyester, polyester fabric and defined PIB composition ranges.
• The strongest infringement risk is for a patch duplicating the complete laminate and adhesive architecture.
• The most direct design-around strategies are changing the overlay adhesive, using heat sealing, changing the volatile component, or eliminating the claimed perimeter geometry.
• Patent expiration cannot be determined from the grant date alone.
• Orange Book listing, Paragraph IV activity, litigation and settlement status require record-level verification separate from claim analysis.

FAQs About US Patent 8,747,888

Does US 8,747,888 cover all levonorgestrel patches?

No. It covers only levonorgestrel patches that also satisfy the structural, adhesive, volatile-component and perimeter-sealing limitations incorporated through the relevant claims.

Can a patch infringe if it uses ethinyl estradiol without levonorgestrel?

Yes, potentially. Claim 1 is not limited to contraceptive actives. A patch using another active ingredient could infringe if it meets every limitation of claim 1.

Is DMSO alone enough to create infringement risk?

No. DMSO is only one required chemical limitation. The product must also meet the claimed polyacrylate drug-layer, PIB overlay, perimeter-seal, intermediate-layer and non-heat-sealing limitations.

Does a different release liner avoid the patent?

It may avoid dependent claims directed to fluorinated or siliconized liners, but not necessarily claim 1. Claim 1 requires a release liner extending beyond the AI layer and participating in the overlay PSA seal, without limiting the liner to a particular material.

Does US 8,747,888 protect the method of applying the patch?

No. The issued claims provided are directed to a transdermal drug delivery device. They do not claim patient treatment, dosing schedules or the act of applying the patch.

Can a generic launch after patent expiration proceed without a Paragraph IV challenge?

If the patent is listed for the relevant reference product and remains unexpired when the abbreviated application is filed, a certification may still be required. The applicable certification and launch consequences depend on the product’s regulatory pathway, listing status and filing date.

References

1. United States Code. (2024). 35 U.S.C. § 154: Contents and term of patent; provisional rights.

2. United States Patent and Trademark Office. (2024). Patent Center: Patent application and patent-term records.

3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.

4. Code of Federal Regulations. (2024). 21 C.F.R. § 314.53: Submission of patent information.

5. United States Code. (2024). 21 U.S.C. § 355(j)(2)(A)(vii)(IV): Paragraph IV patent certification.

6. United States Patent and Trademark Office. (2014). US Patent No. 8,747,888, transdermal drug delivery device.

Drugs Protected by US Patent 8,747,888

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Agile	TWIRLA	ethinyl estradiol; levonorgestrel	SYSTEM;TRANSDERMAL	204017-001	Feb 14, 2020		RX	Yes	Yes			Y

International Family Members for US Patent 8,747,888

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2008275101
Brazil	PI0814697
Canada	2692884
China	101801321
Eurasian Patent Organization	020208