United States Patent 10,307,379: Donepezil Transdermal Composition, Claim Scope, Exclusivity and Patent Landscape

U.S. Patent No. 10,307,379 protects a transdermal donepezil composition that generates donepezil base in situ from a donepezil salt and sodium or potassium bicarbonate. The patent focuses on the drug reservoir, hydrophilic solvent system, acrylate copolymer, and specified skin-contact adhesive components. Its principal commercial relevance is the FDA-approved ADLARITY donepezil transdermal system.

The broadest issued claims are composition claims 1 and 10. Claim 1 is limited to donepezil HCl. Claim 10 covers a broader class of donepezil salts, subject to the same bicarbonate, solvent, acrylate copolymer, adhesive, and in-situ conversion requirements. The patent does not claim oral donepezil, donepezil alone, or every possible donepezil patch.

What does U.S. Patent 10,307,379 protect?

The patent protects a multilayer transdermal composition with two functionally distinct components:

A drug reservoir containing a donepezil salt, alkaline bicarbonate salt, hydrophilic solvent, and acrylate copolymer.
A skin-contact adhesive containing at least one of triethyl citrate, sorbitan monolaurate, or lauryl lactate.

The claims require that contact with skin causes the alkaline salt to react with the donepezil salt and generate a therapeutically effective amount of donepezil base in the reservoir.

Claim element	Claim 1 requirement	Claim 10 requirement
Dosage form	Transdermal composition	Transdermal composition
Active ingredient	Donepezil HCl	Donepezil salt
Alkaline agent	Sodium bicarbonate or potassium bicarbonate	Sodium bicarbonate or potassium bicarbonate
Stoichiometry	Equimolar or less than equimolar alkaline salt	Equivalent or less than equivalent alkaline salt
Solvent	Hydrophilic solvent	Hydrophilic solvent
Polymer	Acrylate copolymer	Acrylate copolymer
Adhesive	Triethyl citrate, sorbitan monolaurate, lauryl lactate, or combination	Same
Functional result	Donepezil base generated in situ after skin attachment	Same

The patent therefore covers a formulation architecture rather than a particular patch shape, backing layer, release liner, package, or treatment regimen.

How broad are the independent claims?

Claim 1: donepezil hydrochloride composition

Claim 1 requires donepezil HCl specifically. A competing patch using a different donepezil salt would not literally satisfy the donepezil HCl limitation, although it could fall within claim 10 if the other limitations are met.

Claim 1 also requires:

Sodium bicarbonate or potassium bicarbonate.
An equimolar or lower molar quantity of alkaline salt relative to donepezil HCl.
A hydrophilic solvent.
An acrylate copolymer.
A skin-contact adhesive containing at least one specified excipient.
In-situ generation of therapeutically effective donepezil base following skin attachment.

The claim is narrower than a generic claim to any donepezil transdermal system. A patch using a non-bicarbonate base, a non-acrylate polymer, or an adhesive without any listed excipient may avoid literal infringement.

Claim 10: broader donepezil-salt composition

Claim 10 is commercially more significant because it replaces donepezil HCl with “a donepezil salt.” Claim 17 narrows claim 10 back to donepezil HCl.

Potentially covered salts include donepezil hydrochloride and other pharmaceutically acceptable donepezil salts, provided the formulation otherwise meets the claim. The claim does not expressly limit the salt to hydrochloride, but the salt must participate in the claimed in-situ conversion process.

The broader salt language creates a larger design-around burden. Changing from donepezil HCl to another salt may not avoid the patent if the alternative salt remains within claim 10.

What dependent claims add formulation protection?

Claims 2 through 9 and 11 through 18 create concentration, solvent, and ingredient fallbacks.

Claims	Added limitation
2	Solvent composition contains one or more listed adhesive excipients
3, 11	Solvent contains 8-12 wt% triethyl citrate, 1.5-2.5 wt% sorbitan monolaurate, and 1-10 wt% lauryl lactate
4, 12	Adhesive contains 1-20 wt% triethyl citrate, 0.01-5 wt% sorbitan monolaurate, and 0.1-10 wt% lauryl lactate
5, 13	Hydrophilic solvent selected from PEG, propylene glycol, glycerin, acetonitrile, 1-propanol, or DMF
6, 14	Hydrophilic solvent is glycerin
7, 15	Glycerin concentration is 5-15 wt%
8, 16	Sodium bicarbonate concentration is 1-5 wt%
9, 18	Donepezil HCl concentration is 5-25 wt%
17	Donepezil salt is donepezil HCl

Claims 3, 4, 7, 8, 9, 11, 12, 15, 16, and 18 are composition-range claims. They can be important in litigation because a product that escapes the broad independent claim may still infringe a narrower claim if its formulation falls within the specified ranges.

What is the patent’s expiration date?

The patent issued on June 4, 2019. Its published patent record identifies a September 16, 2014 priority date and a nominal expiration date of September 16, 2035, subject to any applicable patent-term adjustment, terminal disclaimer, or other term determination recorded by the USPTO.[1]

Milestone	Date
Earliest identified priority date	September 16, 2014
Patent issued	June 4, 2019
Nominal patent expiration	September 16, 2035
Regulatory product associated with the formulation	ADLARITY

The patent’s remaining term is commercially material because the underlying donepezil molecule is old and oral donepezil products have long been generic. The principal barrier is the transdermal delivery technology, not API exclusivity.

What is the Orange Book status of U.S. Patent 10,307,379?

U.S. Patent 10,307,379 has been associated with ADLARITY, the donepezil transdermal system approved by FDA in March 2022 for the treatment of dementia of the Alzheimer’s type.[2][3]

ADLARITY is a once-weekly transdermal system available in 5 mg/day and 10 mg/day strengths. The product delivers donepezil through the skin and avoids the daily oral administration required by conventional tablets.[2]

The Orange Book is the relevant FDA database for listed patents and exclusivity covering approved small-molecule drug products. The listing of a formulation patent can trigger a statutory stay if an ANDA applicant files a valid Paragraph IV certification and the NDA holder or patent owner brings suit within the statutory period.[4]

The patent’s practical Orange Book significance depends on:

Whether it remains listed for the relevant ADLARITY strength or product presentation.
Whether the listed claims correspond to the approved product.
Whether the patent has been delisted, withdrawn, or replaced by later patents.
Whether an ANDA applicant has made a Paragraph IV certification.
Whether litigation has been filed within 45 days of notice.

The claim text alone does not establish the existence or timing of a Paragraph IV notice. FDA Orange Book records and federal court dockets control those issues.

When does donepezil transdermal exclusivity end?

The relevant exclusivity timeline has several layers.

Exclusivity type	Status
Donepezil active-ingredient exclusivity	Expired
Oral donepezil generic competition	Established
ADLARITY FDA approval	March 2022
Transdermal formulation patent	Nominally extends to September 2035
Small-molecule biosimilar protection	Not applicable
ANDA launch before patent expiry	Dependent on certification, litigation, settlement, and court outcome

FDA approved ADLARITY under the 505(b)(2) pathway rather than as a conventional generic substitution for an oral donepezil product.[2] The regulatory product is therefore protected by the combination of FDA exclusivity, product-specific patent listings, and formulation know-how.

The patent does not create exclusivity over the donepezil molecule. A company may continue to sell oral donepezil products without practicing the claimed transdermal composition.

What does the patent require for infringement?

An accused patch would generally need to satisfy every limitation of at least one asserted claim. The principal infringement questions are formulation and process questions.

Drug reservoir

The accused product must have a reservoir containing the claimed donepezil salt, alkaline salt, hydrophilic solvent, and acrylate copolymer. A product using a different polymer family or no acrylate copolymer may have a noninfringement position.

Bicarbonate chemistry

The claim requires sodium bicarbonate or potassium bicarbonate. Other alkalizing agents, including sodium carbonate, potassium carbonate, hydroxides, or organic bases, are outside the literal wording unless a court applies the doctrine of equivalents.

The molar relationship also matters. The alkaline salt must be equimolar or less than equimolar relative to the donepezil salt. A formulation using an excess of bicarbonate could challenge literal infringement, although the effect of that difference would depend on claim construction and prosecution history.

Adhesive composition

At least one of three listed components must be present in the skin-contact adhesive:

Triethyl citrate.
Sorbitan monolaurate.
Lauryl lactate.

The listed excipient can appear alone or in combination. Claims 3 and 4 impose narrower concentration ranges, but claims 1 and 10 do not specify a minimum concentration for those adhesive ingredients.

In-situ conversion

The claims require more than the presence of donepezil salt and bicarbonate. They require a reaction that generates a therapeutically effective amount of donepezil base in situ when the adhesive is attached to skin.

This limitation creates potential evidentiary disputes involving:

The chemical identity of the permeating species.
The timing and location of conversion.
Whether conversion occurs in the reservoir, adhesive, skin, or multiple locations.
Whether the generated amount is therapeutically effective.
Whether the product is designed to produce the claimed reaction or merely contains both ingredients.

What formulations are protected by the patent?

The strongest formulation coverage is directed to a glycerin-containing matrix or reservoir system using bicarbonate and an acrylate copolymer.

A formulation falls within the most specific disclosed claim cluster if it contains:

Donepezil HCl at 5-25 wt%.
Sodium bicarbonate at 1-5 wt%.
Glycerin at 5-15 wt%.
Triethyl citrate at 8-12 wt%.
Sorbitan monolaurate at 1.5-2.5 wt%.
Lauryl lactate at 1-10 wt%.
An acrylate copolymer.
A skin-contact adhesive containing the listed excipients within the claimed ranges.

The claims also permit alternative hydrophilic solvents, including polyethylene glycol and propylene glycol. Acetonitrile, 1-propanol, and N,N-dimethylformamide are expressly listed, although their commercial and regulatory acceptability would depend on product-specific safety and manufacturing data.

Does the patent cover method-of-use claims?

The claims provided are composition claims. They do not independently claim:

Treating Alzheimer’s disease.
Administering a specified weekly dose.
Applying a patch to a particular anatomical site.
Replacing a patch every seven days.
Treating patients unable to tolerate oral donepezil.

The treatment-related language appears only as part of the composition’s functional requirement that in-situ conversion generate a therapeutically effective amount of donepezil base. That language may affect claim construction and infringement analysis, but it is not a conventional method-of-treatment claim.

A separate patent family could protect dosage regimens, patch geometry, manufacturing processes, or use in patient subpopulations. Those rights cannot be inferred from the claims supplied here.

How strong is the patent estate for ADLARITY?

The patent is strongest against a competing patch that copies the same chemical strategy. Its principal strengths are:

Coverage of donepezil salts rather than only donepezil HCl through claim 10.
Express coverage of sodium and potassium bicarbonate.
Coverage of multiple hydrophilic solvents.
Adhesive coverage based on three named excipients.
Functional coverage of in-situ generation of donepezil base.
Narrow concentration claims that provide fallback positions.

The main vulnerabilities are:

The claims are limited to a particular reservoir and adhesive architecture.
The bicarbonate limitation creates a direct design-around route.
The acrylate copolymer limitation excludes patches using other polymer systems.
The functional conversion requirement may require detailed product testing.
Concentration ranges can be avoided by moving outside the claimed intervals, unless another claim is met.
The patent does not block oral or other non-transdermal donepezil products.

The estate is therefore strong against close formulation copies but less powerful against a genuinely different transdermal technology.

Which companies are challenging the patent?

The supplied claims do not identify an ANDA applicant, Paragraph IV notice, litigation defendant, settlement agreement, or licensee. FDA’s Orange Book and federal court records are the controlling sources for any current challenge.

No biosimilar challenge applies because donepezil is a small-molecule active ingredient. A competing transdermal product would most likely use an ANDA, 505(b)(2) application, or an abbreviated pathway determined by FDA’s product-specific requirements. An ANDA applicant would need to address listed patents through Paragraph I, II, III, or IV certification, or a section viii statement where applicable.[4]

What generic launch scenarios exist?

Scenario 1: Oral generic competition continues

This scenario does not directly threaten the patent. Generic tablets and orally disintegrating tablets can compete with ADLARITY without practicing the claimed patch composition.

Scenario 2: A noninfringing transdermal design launches

A competitor could seek to avoid the claims by changing one or more core features:

Use a non-bicarbonate alkalizing agent.
Use a non-acrylate polymer.
Use an alternative adhesive system.
Eliminate the claimed excipients from the skin-contact adhesive.
Use donepezil free base rather than a donepezil salt.
Avoid in-situ conversion from a salt.
Use a different reservoir architecture.

Each design-around must be evaluated against all issued claims, including the broader salt claim and the dependent formulation claims.

Scenario 3: Paragraph IV litigation

An ANDA applicant could challenge validity, enforceability, or infringement. Likely validity theories would focus on:

Anticipation by earlier transdermal donepezil formulations.
Obviousness based on donepezil salt conversion, bicarbonate chemistry, and adhesive technology.
Written description and enablement for the broader “donepezil salt” language.
Definiteness of “equimolar or less than equimolar,” “therapeutically effective amount,” and “in situ.”

The patent holder would likely rely on the specific combination of excipients, polymer, stoichiometry, and demonstrated skin-delivery performance.

Scenario 4: Settlement or licensed entry

A settlement could permit an authorized generic or limited-date transdermal launch before September 2035. No settlement terms or license identified in the supplied record establish such an arrangement.

How does this patent compare with competing dementia products?

Product	Active ingredient	Delivery	Relationship to U.S. 10,307,379
ADLARITY	Donepezil	Weekly transdermal	Direct commercial product associated with the patent
Aricept generics	Donepezil	Oral tablet or ODT	Does not generally practice the claimed patch composition
Exelon patch	Rivastigmine	Transdermal	Different active ingredient and formulation estate
Oral rivastigmine	Rivastigmine	Oral	No direct claim overlap
Namenda products	Memantine	Oral or extended release	Different active ingredient

ADLARITY’s commercial differentiation is the weekly transdermal route. The patent’s value is tied to preserving that route, not to blocking the broader donepezil market.

What are the revenue and commercial risks?

Revenue exposure is concentrated in the transdermal donepezil segment. The patent does not protect all donepezil revenue because oral generic competition is already established.

The principal commercial risks are:

A noninfringing transdermal competitor reaches the market.
An ANDA applicant successfully invalidates or avoids the listed patent.
A court construes “donepezil salt,” “therapeutically effective amount,” or “in situ” narrowly.
FDA approves a competing 505(b)(2) patch with a different formulation.
The product’s weekly-delivery advantage does not support a sufficient premium over low-cost oral generics.

The principal defenses are the formulation’s specific chemical architecture and the practical difficulty of matching skin flux, adhesion, irritation, stability, and seven-day delivery at commercial scale.

What manufacturing and intellectual-property barriers remain?

The patent creates barriers beyond ingredient selection. A competitor must reproduce or replace several interdependent functions:

Uniform drug loading in the reservoir.
Controlled salt-to-base conversion.
Stable incorporation of bicarbonate.
Adequate donepezil solubilization.
Seven-day skin flux.
Adhesive performance during wear.
Acceptable irritation and sensitization profile.
Consistent coating, drying, lamination, and packaging.
Chemical and physical stability over shelf life.

Manufacturing patents, trade secrets, coating-process controls, adhesive know-how, and clinical bridging data may remain important even if a competitor avoids literal infringement. Those barriers are separate from the claims of U.S. 10,307,379.

Key Takeaways

U.S. Patent 10,307,379 protects a donepezil transdermal composition that converts donepezil salt to donepezil base in situ.
Claim 1 covers donepezil HCl; claim 10 covers a broader class of donepezil salts.
Sodium or potassium bicarbonate, a hydrophilic solvent, an acrylate copolymer, and specified adhesive excipients are central claim limitations.
Claims 3, 4, 7, 8, 9, 11, 12, 15, 16, and 18 add concentration-based fallback protection.
The patent issued June 4, 2019, with a nominal expiration date of September 16, 2035, based on the identified priority date.
ADLARITY is the principal commercial product associated with the claimed transdermal technology.
There is no biosimilar pathway for donepezil. Competitive entry would arise through an ANDA, 505(b)(2) application, or a noninfringing transdermal design.
The patent is strongest against close copies using bicarbonate, acrylate copolymers, and the specified adhesive system.
Oral donepezil generics generally do not practice the patent and remain outside its core claim scope.

FAQs About U.S. Patent 10,307,379

Does U.S. Patent 10,307,379 cover all donepezil patches?

No. It covers patches with the claimed reservoir, bicarbonate salt, hydrophilic solvent, acrylate copolymer, adhesive excipient, and in-situ donepezil-base generation features.

Can a competitor use donepezil free base to avoid the patent?

Potentially. The claims require a donepezil salt in the reservoir. A free-base formulation would not literally satisfy that limitation, although other patents and the doctrine of equivalents could remain relevant.

Does using potassium bicarbonate instead of sodium bicarbonate avoid the patent?

No. Both sodium bicarbonate and potassium bicarbonate are expressly recited alternatives.

Is the patent relevant to generic Aricept tablets?

Generally no. The claims are directed to a transdermal composition and do not cover ordinary oral donepezil tablets.

What is the most important design-around issue?

The most important issue is whether a competing patch can avoid the combined bicarbonate, acrylate-copolymer, adhesive-excipient, and in-situ conversion limitations while maintaining equivalent seven-day delivery performance.

References

United States Patent and Trademark Office. (2019). U.S. Patent No. 10,307,379, transdermal delivery of donepezil. https://patents.google.com/patent/US10307379B2/en
U.S. Food and Drug Administration. (2022). FDA approves first once-weekly transdermal treatment for Alzheimer’s disease. https://www.fda.gov
U.S. Food and Drug Administration. (2022). ADLARITY (donepezil) transdermal system prescribing information. https://www.accessdata.fda.gov
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Corium	ADLARITY	donepezil hydrochloride	SYSTEM;TRANSDERMAL	212304-001	Mar 11, 2022		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
Corium	ADLARITY	donepezil hydrochloride	SYSTEM;TRANSDERMAL	212304-002	Mar 11, 2022		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2017301928	⤷ Start Trial
Australia	2017301929	⤷ Start Trial
Australia	2017302305	⤷ Start Trial
Australia	2017302306	⤷ Start Trial
Australia	2017302307	⤷ Start Trial
Australia	2023203613	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,307,379

Which drugs does patent 10,307,379 protect, and when does it expire?

Summary for Patent: 10,307,379