United States Patent 5,786,390: Rasagiline Composition Claims, Expiration, and Patent Landscape

U.S. Patent No. 5,786,390 covers pharmaceutical compositions containing the R(+)-enantiomer of N-propargyl-1-aminoindan, now known as rasagiline, including salts, tablets, injectable solutions, suppositories, and combinations with levodopa or decarboxylase inhibitors. The patent does not claim rasagiline as a chemical compound in the abstract. Its enforceable scope is directed to compositions containing rasagiline or a pharmaceutically acceptable salt, subject to the limitations in each claim.

The patent was commercially important to Azilect, the rasagiline product marketed by Teva Pharmaceutical Industries Ltd. The patent’s statutory term has expired. It therefore does not create a current U.S. barrier to generic rasagiline products, although related patents historically covered the active ingredient, therapeutic uses, formulations, and dosing regimens.

What does U.S. Patent 5,786,390 protect?

U.S. Patent 5,786,390 protects pharmaceutical compositions containing R(+)-N-propargyl-1-aminoindan, rasagiline, or an acceptable salt of rasagiline, together with a pharmaceutically acceptable carrier.[1]

The independent claims are:

Claim	Protected subject matter	Key limitations
1	Rasagiline pharmaceutical composition	Rasagiline or salt, therapeutically effective amount, pharmaceutically acceptable carrier
10	Rasagiline plus levodopa	Both active ingredients and a carrier
13	Rasagiline plus decarboxylase inhibitor	Rasagiline, decarboxylase inhibitor, and a carrier

The remaining claims depend on these claims and narrow the scope by specifying dosage form, concentration, salt, active ingredient, or dose range.

The patent is therefore a composition patent with three principal claim groups:

Rasagiline alone.
Rasagiline combined with levodopa.
Rasagiline combined with carbidopa or benserazide.

How broad is claim 1 of U.S. Patent 5,786,390?

Claim 1 is the broadest claim in the patent. It requires four elements:

A pharmaceutical composition.
A therapeutically effective amount of R(+)-N-propargyl-1-aminoindan.
Rasagiline in free-base form or as a pharmaceutically acceptable salt.
A pharmaceutically acceptable carrier.

The claim uses the phrase “consists essentially of.” That transitional phrase generally permits excipients and other components that do not materially alter the basic and novel characteristics of the composition. It is narrower than “comprising” but broader than “consisting of.”

A composition would likely fall within claim 1 if it contains rasagiline, an acceptable rasagiline salt, and ordinary pharmaceutical excipients such as:

Lactose
Microcrystalline cellulose
Starch
Povidone
Magnesium stearate
Water
Injectable solvents
Suppository bases

Claim 1 does not limit the composition to a particular tablet, capsule, injection, or dosage strength. It also does not specify a particular excipient, manufacturing process, release profile, particle size, polymorph, or packaging system.

What dosage forms and strengths are covered?

The patent expressly identifies three dosage forms.

Tablets

Claims 2 through 4 cover solid compositions formulated as tablets. The specified rasagiline dose ranges are:

Claim	Rasagiline amount
Claim 3	About 0.1 mg to about 100 mg
Claim 4	About 1 mg to about 10 mg

The “about” language creates a range boundary that is not mathematically exact. A product containing 1 mg of rasagiline would fall within claim 4 if the remaining claim elements were present. A typical 0.5 mg or 1 mg tablet would also fall within the broader range in claim 3.

Azilect tablets were marketed primarily in 0.5 mg and 1 mg strengths. Those strengths fall below the literal lower boundary of claim 4 but within the broader 0.1 mg to 100 mg range of claim 3.[2]

Injectable solutions

Claims 5 through 7 cover liquid pharmaceutical compositions formulated as injectable solutions.

Claim	Rasagiline concentration
Claim 6	About 0.1 mg/ml to about 100 mg/ml per dosage unit
Claim 7	About 1 mg/ml to about 10 mg/ml per dosage unit

These claims require an injectable solution, not merely a liquid oral formulation. An oral solution, ophthalmic solution, or transdermal liquid would not satisfy the injectable-solution limitation unless another claim or doctrine applied.

Suppositories

Claim 8 covers a composition in which the carrier is a gel and the dosage form is a suppository. This claim is narrower than claim 1 because it requires both:

A gel carrier; and
A suppository dosage form.

A solid tablet or injectable solution would not infringe claim 8.

What salts are protected by Patent 5,786,390?

Claim 9 specifically identifies the mesylate salt of rasagiline. The broader claims refer to pharmaceutically acceptable salts generally.

Rasagiline mesylate is the active pharmaceutical ingredient used in Azilect. The salt limitation has two effects:

Claims 1, 10, and 13 cover rasagiline free base and pharmaceutically acceptable salts.
Claim 9 narrows the composition to rasagiline mesylate.

Potentially covered salts include salts formed with pharmaceutically acceptable acids, subject to the patent’s disclosure and claim construction. A competing product using a different salt would still face claim 1 if that salt qualifies as pharmaceutically acceptable. It would not necessarily fall within claim 9, which is expressly limited to mesylate.

What combination products are covered?

Rasagiline and levodopa

Claims 10 through 12 cover compositions containing both rasagiline and levodopa.

Claim	Rasagiline amount	Levodopa amount
Claim 10	Therapeutically effective amount	Therapeutically effective amount
Claim 11	About 0.1 mg to about 100 mg	About 50 mg to about 250 mg
Claim 12	About 0.1 mg to about 100 mg	About 50 mg to about 200 mg

Claim 10 is not limited to a specific dose. Claims 11 and 12 impose quantitative ranges.

A fixed-dose combination tablet containing 1 mg rasagiline and 100 mg levodopa would fall within both claims 11 and 12, assuming the carrier and other claim requirements are met. A product containing levodopa outside the stated ranges could still fall within claim 10.

Rasagiline and decarboxylase inhibitors

Claims 13 through 19 cover rasagiline combined with a decarboxylase inhibitor.

The patent identifies two inhibitors:

L-carbidopa
Benserazide

Claim	Rasagiline amount	Inhibitor	Inhibitor amount
Claim 13	Therapeutically effective amount	Any decarboxylase inhibitor	Therapeutically effective amount
Claim 14	Therapeutically effective amount	L-carbidopa	Not specified
Claim 15	Therapeutically effective amount	Benserazide	Not specified
Claim 16	About 0.1 mg to about 100 mg	Any decarboxylase inhibitor	About 10 mg to about 25 mg
Claim 17	About 0.1 mg to about 100 mg	L-carbidopa	About 10 mg to about 25 mg
Claim 18	About 0.1 mg to about 100 mg	Any decarboxylase inhibitor	About 12.5 mg to about 50 mg
Claim 19	About 0.1 mg to about 100 mg	Benserazide	About 12.5 mg to about 50 mg

These claims are potentially relevant to future fixed-dose Parkinson’s disease combinations, but they do not cover every product containing rasagiline and levodopa. A composition containing rasagiline and levodopa but no decarboxylase inhibitor would be evaluated under claims 10 through 12, not claims 13 through 19.

What is the claim-by-claim scope?

Claim	Scope assessment
1	Broad composition claim covering rasagiline or a pharmaceutically acceptable salt with a carrier
2	Tablet limitation
3	Tablet with approximately 0.1 mg to 100 mg rasagiline
4	Tablet with approximately 1 mg to 10 mg rasagiline
5	Injectable-solution limitation
6	Injectable solution with approximately 0.1 mg/ml to 100 mg/ml
7	Injectable solution with approximately 1 mg/ml to 10 mg/ml
8	Gel-carrier suppository
9	Rasagiline mesylate
10	Rasagiline plus levodopa
11	Combination with 50 mg to 250 mg levodopa
12	Combination with 50 mg to 200 mg levodopa
13	Rasagiline plus a decarboxylase inhibitor
14	Rasagiline plus L-carbidopa
15	Rasagiline plus benserazide
16	Rasagiline plus inhibitor in specified dose ranges
17	Rasagiline plus L-carbidopa in specified dose ranges
18	Rasagiline plus inhibitor in narrower or overlapping ranges
19	Rasagiline plus benserazide in specified dose ranges

Claims 1, 10, and 13 carry the principal commercial significance because they are the independent claims. Claims 2 through 9 and 11 through 19 narrow the independent claims and may be easier to avoid through formulation design.

When did U.S. Patent 5,786,390 lose exclusivity?

The patent issued on July 28, 1998.[1] Its U.S. application was filed in December 1996, with priority to an earlier foreign filing. The ordinary 20-year patent term is measured from the earliest effective U.S. nonprovisional filing date under the modern patent-term rules.

The patent’s practical Orange Book protection for rasagiline products ended in the 2010s. Historical Orange Book listings associated with Azilect reported expiration in December 2017, reflecting the applicable patent-term calculation and any available extension.[2] The patent is now expired and cannot be used to block a current generic launch.

Event	Date
Priority filing	December 1994
U.S. application filing	December 1996
Patent issued	July 28, 1998
Historical Azilect patent protection	December 2017
Current status	Expired

Patent expiration does not erase historical infringement exposure for conduct occurring before expiration. It eliminates prospective enforcement after the expiration date.

What was the Orange Book status of Patent 5,786,390?

Patent 5,786,390 was listed in the FDA Orange Book for rasagiline products associated with Azilect. The listing supported the branded product’s patent certifications and generic approval process under the Hatch-Waxman Act.[2]

The relevant regulatory consequences were:

An ANDA applicant had to address the listed patent.
A Paragraph IV certification could trigger patent litigation.
A timely infringement action could impose a 30-month stay of FDA approval.
Once the relevant patent protection expired, the patent no longer supported a continuing approval block.

Patent 5,786,390 was not a biologic patent. Rasagiline is a small-molecule drug. Generic competitors would use the ANDA pathway rather than the biosimilar pathway under section 351(k) of the Public Health Service Act.

Were Paragraph IV challenges relevant?

Yes. Because the patent was listed for an approved small-molecule product, generic applicants could submit a Paragraph IV certification asserting that the patent was invalid, unenforceable, or would not be infringed.[3]

The commercial importance of a Paragraph IV challenge depended on:

Whether the ANDA product contained rasagiline mesylate.
Whether the product used a tablet or another dosage form.
Whether the applicant certified against claim 1 or narrower dependent claims.
Whether the branded company filed suit within 45 days.
Whether other Orange Book patents covered the active ingredient or method of use.

A standard 0.5 mg or 1 mg rasagiline tablet would have been the principal generic product at issue. The composition claims were relevant because they could read on the active ingredient and carrier combination even when the generic manufacturer used different excipients.

Which related patents affected rasagiline generic entry?

Patent 5,786,390 was part of a broader rasagiline estate. Related U.S. patents covered the molecule, therapeutic uses, and methods of treatment.

Patent	General subject matter	Commercial relevance
U.S. 5,532,415	Rasagiline-related compound and pharmaceutical applications	Core active-ingredient and product protection
U.S. 5,786,390	Rasagiline pharmaceutical compositions	Formulation and combination protection
U.S. 6,316,023	Therapeutic use of rasagiline	Method-of-use protection
U.S. 6,630,514	Rasagiline treatment methods and dosing/use concepts	Later method-of-use protection

The exact infringement analysis depends on the asserted claims, prosecution history, patent-term adjustments, terminal disclaimers, and the ANDA’s proposed labeling. A generic tablet could avoid a method-of-use claim through a compliant label while still implicating a composition claim.

How strong is the patent estate for rasagiline?

The estate was commercially strong during the branded exclusivity period because it combined several patent categories:

Active-ingredient protection

The strongest form of protection generally covers the chemical compound itself. If valid and enforceable, a compound claim can reach tablets, capsules, solutions, and other products containing the compound regardless of excipient selection.

Composition protection

Patent 5,786,390 covered pharmaceutical compositions and selected combinations. Its breadth was meaningful but narrower than a pure compound claim because the accused product had to contain a pharmaceutical carrier and satisfy the “consists essentially of” language.

Method-of-use protection

Related patents covered treatment of Parkinson’s disease and other neurological conditions. These claims could remain commercially relevant after composition claims expired if the branded label and generic label overlapped in a protected indication.

Combination protection

The levodopa, carbidopa, and benserazide claims targeted combination therapy. Their value was limited for a conventional Azilect monotherapy tablet but potentially significant for future fixed-dose combinations.

The estate’s current strength is limited by expiration. Patent 5,786,390 is no longer an effective barrier to U.S. generic entry.

What generic launch risks existed?

Before expiration, generic applicants faced four main risks:

Patent litigation after a Paragraph IV certification.
A 30-month FDA approval stay.
Infringement claims based on the composition claims.
Method-of-use claims associated with Parkinson’s disease labeling.

After expiration, the principal risks shifted from patent infringement to regulatory and commercial execution:

ANDA approval requirements
Bioequivalence
Manufacturing scale-up
Controlled quality of rasagiline mesylate
Stability and impurity control
Pricing pressure from multiple generic entrants
Substitution and formulary access

There is no biosimilar risk because rasagiline is not a biologic. The relevant competitive threat is generic substitution.

What manufacturing and formulation barriers remain?

Patent 5,786,390 does not impose a substantial current manufacturing barrier. Its claims do not require a particular process, polymorph, particle-size distribution, coating, dissolution profile, or excipient system.

The main technical barriers are operational:

Maintaining rasagiline mesylate assay and impurity specifications
Controlling degradation during tableting and storage
Achieving bioequivalence against the reference listed drug
Establishing appropriate dissolution performance
Preventing cross-contamination in low-dose manufacturing
Qualifying active pharmaceutical ingredient suppliers

A generic manufacturer can generally design around the narrower claims by selecting a different dosage form or combination profile. That design-around analysis is unnecessary for an expired patent but remains relevant to historical litigation and patent-validity reviews.

What licensing deals affected the patent landscape?

Teva Pharmaceutical Industries was the principal commercial holder associated with Azilect and the relevant U.S. patent portfolio. Rasagiline originated from research associated with Technion-Israel Institute of Technology and collaborators, with commercialization rights involving Teva.[4]

The commercial arrangement was important because Teva controlled the branded product and coordinated Orange Book patent enforcement. Generic manufacturers later entered through ANDA approvals and commercial agreements or litigation resolutions associated with the branded portfolio.

No current license to Patent 5,786,390 can block generic U.S. commercialization after expiration. A license may still matter for foreign patents, know-how, trademarks, or other non-expired rights, but those rights are separate from the expired U.S. composition patent.

How does Patent 5,786,390 compare with a compound patent?

Issue	Patent 5,786,390	Compound patent
Claim type	Pharmaceutical composition	Chemical compound
Requires carrier	Yes	Usually no
Covers free base or salts	Yes, subject to claim language	Depends on claim
Covers all dosage forms	No, depending on claim	Often broader
Easy formulation design-around	Sometimes	Usually difficult
Relevance to generic tablet	High historically	High
Current blocking power	None after expiration	Depends on expiration
Combination protection	Yes, in claims 10-19	Usually not unless specifically claimed

Patent 5,786,390 was narrower than a valid compound patent but broader than a narrowly drafted tablet or injectable formulation patent. Its strongest practical claims were claim 1 for monotherapy compositions and claim 10 for rasagiline-plus-levodopa combinations.

Key Takeaways

U.S. Patent 5,786,390 covers rasagiline pharmaceutical compositions, including rasagiline mesylate.
Claim 1 is the broadest claim and covers rasagiline or an acceptable salt with a pharmaceutical carrier.
Claims 2 through 9 cover tablets, injectable solutions, suppositories, dose ranges, and mesylate salt.
Claims 10 through 19 cover combinations with levodopa, L-carbidopa, and benserazide.
The patent is a composition patent, not a standalone chemical-compound patent.
It was associated with Teva’s Azilect patent portfolio and Orange Book protection.
Historical Orange Book protection extended into December 2017.
The patent is now expired and does not block current U.S. generic rasagiline entry.
Generic competition proceeds through the ANDA pathway, not the biosimilar pathway.
Current commercial risk centers on regulatory approval, bioequivalence, manufacturing, pricing, and market access rather than infringement of Patent 5,786,390.

Frequently Asked Questions

Does Patent 5,786,390 cover Azilect tablets?

Yes. Azilect contains rasagiline mesylate in tablet form, and the patent’s composition and tablet claims were relevant to the branded product.

Does the patent cover a rasagiline capsule?

Potentially, under claim 1, if the capsule contains rasagiline or a pharmaceutically acceptable salt, a therapeutically effective amount, and a pharmaceutically acceptable carrier. The express tablet limitation in claim 2 would not apply.

Does a different rasagiline salt avoid Patent 5,786,390?

Not necessarily. Claim 1 covers rasagiline and pharmaceutically acceptable salts generally. A different salt may avoid the narrower mesylate claim in claim 9 but could still fall within claim 1.

Can a generic company launch rasagiline without licensing this patent?

Yes, because Patent 5,786,390 has expired. A generic applicant must still satisfy FDA approval requirements and evaluate any other unexpired patents or regulatory exclusivities.

Is a fixed-dose rasagiline and levodopa product covered?

Claims 10 through 12 specifically cover rasagiline and levodopa combinations, subject to the claimed dose and carrier limitations. The patent’s expiration removes the current U.S. blocking effect.

References

United States Patent and Trademark Office. (1998). U.S. Patent No. 5,786,390, Pharmaceutical composition containing R(+)-N-propargyl-1-aminoindan. https://patents.google.com/patent/US5786390A/en
U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
U.S. Food and Drug Administration. (2015). Abbreviated new drug application regulations: Patent certifications and 30-month stays. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-314
Teva Pharmaceutical Industries Ltd. (2006). Azilect prescribing information. U.S. Food and Drug Administration labeling database. https://www.accessdata.fda.gov/drugsatfda/♀♀♀♀♀♀?

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Israel	92952	Jan 03, 1990

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0436492	⤷ Start Trial	91195	Luxembourg	⤷ Start Trial
European Patent Office	0436492	⤷ Start Trial	CA 2005 00040	Denmark	⤷ Start Trial
European Patent Office	0812190	⤷ Start Trial	91191	Luxembourg	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,786,390

Summary for Patent: 5,786,390