US Patent 5,457,133: Scope, Claim Strength, and US Patent Landscape for R(+)-N-Propargyl-1-Aminoindan (±-Selegiline-Alternative) and Levodopa Combination Therapy
Executive summary: US 5,457,133 claims (i) the specific chiral active ingredient (+)-N-propargyl-1-aminoindan (and pharmaceutically acceptable acid addition salts); (ii) broad composition claims using R(+)-N-propargyl-1-aminoindan across multiple dosage forms (tablets, parenteral liquid/emulsions, suppositories, transdermal formulations); and (iii) combination therapy claims coupling the compound with levodopa plus either carbidopa or benserazide and defined dose ranges. The independent scope is chemically narrow (one stereochemical entity), while the formulation and use scope is relatively broad (generic “carrier,” broad dosage form language, and wide therapeutic ranges). The practical risk for generic entry is tied to (a) whether later patents broadly cover formulation/processes and (b) whether the compound is used in the claimed levodopa + decarboxylase inhibitor co-formulation space.
What does US Patent 5,457,133 claim for (+)-N-propargyl-1-aminoindan?
Core claim set: The claims you provided map into three enforceable buckets.
Claim 1: Chemical entity and salts
- Claim 1 covers (+)-N-propargyl-1-aminoindan (single stereochemical designation (+)) with its pharmaceutically acceptable acid addition salts.
- Claim boundary effect: This is the tightest claim because it is limited to a specific stereoisomer and specific salt class (acid addition salts).
Litigation leverage: A claim to the compound itself is the strongest form of IP for product entry, because infringement can occur without the competitor proving specific formulation details if the marketed API contains the claimed stereoisomer.
Claim 2-10: Composition and dosage forms
- Claim 2 covers a pharmaceutical composition comprising R(+)-N-propargyl-1-aminoindan (or salt) in a therapeutically effective amount and a carrier.
- Claims 3-5 limit to tablet dosage units and specific 2–20 mg then 5–10 mg per dosage unit.
- Claims 6-8 cover vials/ampoules including aqueous or non-aqueous solutions or emulsions with 1–10 mg/mL then 2–5 mg/mL.
- Claim 9 covers suppository form.
- Claim 10 covers a formulation suitable for transdermal administration.
Scope read-through:
- The chemical limitation remains constant: R(+)-N-propargyl-1-aminoindan (plus salts).
- The carrier language is intentionally broad.
- Dosage forms are listed, but the presence of “suitable for transdermal administration” and “carrier” supports a wide interpretation of excipients and delivery technologies, subject to prosecution history and claim construction.
Claims 11-14: Combination therapy with levodopa + decarboxylase inhibitor
- Claim 11: composition further comprising levodopa.
- Claim 12: adds a decarboxylase inhibitor “in an amount effective to ensure L-Dopa uptake.”
- Claim 13: defines one set of dose ranges:
- 2–10 mg R(+)-N-propargyl-1-aminoindan
- 50–250 mg levodopa
- 10–25 mg L-carbidopa
- Claim 14: defines an alternative inhibitor:
- 2–10 mg R(+)-N-propargyl-1-aminoindan
- 50–200 mg levodopa
- 12.5–50 mg benserazide
Commercial relevance: These claims target a co-formulation or fixed-dose combination positioning with established Parkinson’s supportive agents (carbidopa or benserazide). That makes them more likely to collide with any product that markets levodopa with decarboxylase inhibitor using the claimed propargyl-aminoindan as the additional active.
How broad are the claims in US 5,457,133: stereochemistry, salts, and “therapeutically effective amount”?
Stereochemistry is the gating element
- Claim 1 uses (+)-N-propargyl-1-aminoindan.
- Claim 2 and downstream composition claims use R(+)-N-propargyl-1-aminoindan.
- This is significant because competitors could attempt to avoid infringement by using different stereochemistry. Your provided claim set does not cover S(-) or racemic mixtures, only the R(+)/(+)- stereochemical species.
“Pharmaceutically acceptable acid addition salt” is broad, but bounded
This includes salts formed with acids that are accepted in pharma practice. It does not explicitly extend to base salts, quaternary salts, or special salt families.
“Therapeutically effective amount” adds flexibility but invites construction
- For claims 2 and 11-12, the phrase is not numerically bounded.
- That increases enforceability against products in the same therapeutic space, but it also creates more room for claim construction disputes (what is “therapeutically effective” for a given disease and regimen).
Which dosage forms are explicitly protected (tablets, injection, suppository, transdermal)?
Explicitly covered in your claim set:
- Tablets: claim 3; dosing ranges claim 4 and claim 5.
- Vials/ampoules: claims 6-8 with solution/emulsion and mg/mL ranges.
- Suppositories: claim 9.
- Transdermal: claim 10.
- Combinations: claims 11-14 do not specify dosage form but are written as compositions.
Risk mapping for competitors
- If a competitor markets tablets outside the 5–10 mg and 2–20 mg per dosage unit ranges, it may avoid literal infringement of those dependent claims, but still face exposure under broader claim 2 if its tablets still fall under “therapeutically effective amount.”
- If a competitor uses a non-listed dosage form, claim 2 may still reach it, but the dependent claim set would be inapplicable.
- For parenterals, the mg/mL ranges in claims 7-8 are a concrete infringement boundary.
What is protected for levodopa co-therapy: carbidopa vs benserazide fixed-dose ranges?
Carbidopa combination ranges (claim 13)
- R(+)-N-propargyl-1-aminoindan: 2–10 mg
- Levodopa: 50–250 mg
- L-carbidopa: 10–25 mg
Benserazide combination ranges (claim 14)
- R(+)-N-propargyl-1-aminoindan: 2–10 mg
- Levodopa: 50–200 mg
- Benserazide: 12.5–50 mg
Key insight: These dependent claims function as “design-around grenades.” A product that uses the same active APIs but stays outside one of the numerical subranges may escape dependent claim literal infringement while still potentially landing in claim 12 or claim 11 depending on how “therapeutically effective” is construed.
What patent landscape exists around US 5,457,133 (forms of IP that typically extend beyond a compound claim)?
You provided only the claim text, not the patent’s family structure, assignees, priority dates, or cited references. For a patent landscape analysis that is fit for licensing or litigation use, the following items are typically determinative but cannot be reliably enumerated from the provided inputs alone:
- related continuation patents (same family, different claim scopes);
- process/manufacturing patents for producing the stereochemical intermediate;
- formulation patents for tablets or transdermal systems;
- method-of-use claims for Parkinson’s regimens that might be broader or narrower than the fixed-dose combination in claim 11-14;
- Orange Book listings and FDA label-linked exclusivities;
- Paragraph IV/IVH challenges and settlement history.
No landscape inventory can be produced accurately from the claim text alone.
How strong is the patent estate for this chemistry: infringement hooks and common design-arounds?
Strength drivers
- Compound (Claim 1): direct API coverage is strong for enforcement.
- Combination with levodopa and decarboxylase inhibitors (Claims 11-14): targets a product archetype in a regulated therapeutic area with established co-administered agents.
- Broad carrier/dosage form coverage via Claim 2: helps prevent “dosage form” design-around where the same tablet or liquid uses the claimed stereoisomer and therapeutically effective amount.
Design-arounds suggested by the claim language
- Stereochemical substitution: switching away from R(+)/(+)- to another stereoisomer or racemate could avoid literal infringement.
- Salt form selection: using a non–acid addition salt could avoid claim 1’s salt limitation (but may still infringe claim 2 if it is drafted to cover the base form as “R(+)-N-propargyl-1-aminoindan … or a pharmaceutically acceptable salt.” Your claim set implies salts are alternative cover; avoiding salt may still not avoid claim 2 if the API itself matches).
- Dose-range engineering: moving levodopa or inhibitor doses outside claim 13/14 ranges could avoid those dependent claims, but may not avoid the independent “therapeutically effective” language in claim 11-12.
What is the likely infringement test for a generic or follow-on product?
A party would typically compare:
- Active ingredient identity: does the product contain R(+)-N-propargyl-1-aminoindan (or a covered salt)?
- Formulation composition: is it a composition with a therapeutically effective amount of that API and a carrier?
- Dosage form mapping: does it fall into tablets, parenteral solution/emulsion, suppository, or transdermal?
- Combination presence: does the product include levodopa and a decarboxylase inhibitor effective to ensure L-Dopa uptake?
- Fixed-dose numerical limits: are the amounts within 2–10 mg active plus the levodopa and inhibitor ranges in claims 13-14?
Key takeaways
- US 5,457,133 is structurally narrow on the API (R(+)/(+)-N-propargyl-1-aminoindan and acid addition salts), but formulation and dosage-form coverage is broad via “carrier” and multiple dosage forms.
- Combination therapy is explicitly claimed for levodopa with a decarboxylase inhibitor, with two fixed-dose range variants: carbidopa (claim 13) and benserazide (claim 14).
- Design-around risk is lowest for stereochemistry changes; risk remains for any product that uses the same R(+)/(+)-active and achieves therapeutically effective dosing, even if dosage form or dose distribution differs.
- A complete US landscape view (family members, Orange Book status, Paragraph IV litigation, and expirations) cannot be compiled from the provided claim excerpt alone.
FAQs
1) Can a product avoid US 5,457,133 by changing from tablets to transdermal?
Claim 2 already covers a pharmaceutical composition with R(+)-N-propargyl-1-aminoindan in a therapeutically effective amount and a carrier, and claim 10 explicitly covers transdermal suitability. Changing dosage form alone is unlikely to avoid infringement if the API and amount remain within the claim scope.
2) What protects the formulation beyond the API itself in US 5,457,133?
The patent has dependent claims tied to tablet unit dose and parenteral mg/mL ranges and explicitly includes suppositories and transdermal formulations. There are also combination claims adding levodopa and decarboxylase inhibitors.
3) Do claims 13 and 14 require both carbidopa and benserazide?
No. Claim 13 is the carbidopa range set; claim 14 is the benserazide range set.
4) If a competitor stays outside the levodopa dose range in claim 13, are they safe?
Not necessarily. They may avoid dependent claim 13 literal infringement if outside its numerical limits, but still face claim 11-12 exposure due to “therapeutically effective amount” and “decarboxylase inhibitor … effective to ensure L-Dopa uptake.”
5) Is the core enforcement point the combination therapy or the compound?
The compound coverage (claim 1) is the highest-leverage hook. Combination claims strengthen enforcement for fixed-dose products using levodopa and a decarboxylase inhibitor.
References (APA)
- United States Patent 5,457,133. (Patent claims as provided in user input).
