United States Patent 6,316,023 (Scope, Claims, and US Patent Landscape for (S)-N-ethyl-3-[(1-dimethylamino)ethyl]-N-methylphenyl carbamate Formulations)
What does US 6,316,023 claim in the US market?
US Drug Patent 6,316,023 claims pharmaceutical compositions and transdermal devices built around a specific active: (S)-N-ethyl-3-[(1-dimethylamino)ethyl]-N-methylphenyl carbamate, used as either a free base or an acid addition salt, plus a low dose antioxidant and standard diluent/carrier components. A second independent pathway tightens the formulation by requiring a particular polymeric matrix component (polymethacrylate or an acid addition salt) and a specific antioxidant and level.
The claim set you provided is structurally tight and formulation-forward: it limits (1) active concentration windows, (2) antioxidant identity, and (3) transdermal construction elements (backing layer, adhesive, release liner, and polymer matrix layer).
Core claim coverage (from claims 1–9 provided)
| Claim |
Product type |
Active (S)-N-ethyl-3-[(1-dimethylamino)ethyl]-N-methylphenyl carbamate |
Antioxidant |
Key excipients / structure |
| 1 |
Pharmaceutical composition |
1–40 wt%, free base or acid addition salt |
0.01–0.5 wt% |
Diluent or carrier |
| 2 |
Composition (depends on 1) |
Same as claim 1 |
Antioxidant limited to: tocopherol/tocopherol esters, ascorbic acid/esters, BHT, BHA, propyl gallate; or combinations |
Still requires 0.01–0.5 wt% from claim 1 |
| 3 |
Composition (depends on 2) |
Same as claim 1 |
Limited to α-tocopherol or ascorbyl palmitate |
Still requires 0.01–0.5 wt% from claim 1 |
| 4 |
Composition (depends on 1) |
Same as claim 1 |
0.05–0.2 wt% |
Still includes diluent/carrier |
| 5 |
Composition (depends on 4) |
Same as claim 1 |
0.1–0.15 wt% |
Still includes diluent/carrier |
| 6 |
Pharmaceutical composition |
7–40 wt%, free base |
0.05–0.3 wt% α-tocopherol |
10–30 wt% polymethacrylate or an acid addition salt |
| 7 |
Transdermal device (product-by-formulation) |
1–40 wt%, free base or acid addition salt |
0.01–0.5 wt% |
Diluent/carrier |
| 8 |
Transdermal device (depends on 7) |
Same as claim 7 |
Still requires the antioxidant from claim 7 |
Requires: backing layer, adhesive, release liner |
| 9 |
Transdermal device (depends on 7) |
Same as claim 7 |
Antioxidant in polymer matrix layer |
Requires layered architecture: polymer matrix layer containing active+antioxidant, release liner, and adhesive layer between matrix layer and release liner |
How broad are the claim limits, and what do they mean operationally?
1) Active loading creates a wide “entry corridor,” but the formulation context constrains it
- Claim 1 (1–40 wt%) and Claim 7 (1–40 wt%) are broad on active loading: a manufacturer has substantial headroom to tune dose strength and patch size while staying in range.
- Claim 6 (7–40 wt%) narrows minimum active content. It captures compositions where the active is the dominant component or where high drug loading pushes toward the upper end of patch formulation realities.
2) Antioxidant dose is a second “entry corridor” and it is claim-critical
- Claim 1 / Claim 7: 0.01–0.5 wt% antioxidant.
- Dependent narrowing:
- Claim 4: 0.05–0.2 wt%
- Claim 5: 0.1–0.15 wt%
- Claim 6: requires α-tocopherol specifically and 0.05–0.3 wt%
This creates practical design-around paths that depend on staying outside every claimed antioxidant window, not just one. A product that uses antioxidants below 0.01 wt% or above 0.5 wt% avoids the baseline formulation claim. Using a non-enumerated antioxidant may also avoid claim 2/3, but the independent claim still allows “an antioxidant” generically at 0.01–0.5 wt% (so identity is not controlling for claim 1/7).
3) Antioxidant identity limits apply only when those dependent claims are asserted
- Claim 2 is an antioxidant species lock for compositions that fall inside claim 1. If a competitor uses a different antioxidant, it avoids claims 2 and 3, but it may still infringe claim 1 or claim 7 if dose and the active/carrying components match.
- Claim 3 tightens further to α-tocopherol or ascorbyl palmitate.
4) Transdermal device claims are layered-architecture oriented
Claim 7 is already “device comprising a pharmaceutical composition” (product-by-formulation). Claims 8 and 9 add structural requirements:
- Claim 8: backing layer + adhesive + release liner.
- Claim 9: a specific layer arrangement:
- a matrix layer comprising active + antioxidant in a polymer matrix
- a release liner
- an adhesive layer between the matrix layer and the release liner that releasably fixes to skin
That means a device that uses a different construction (for example, where the adhesive is not in the recited location relative to the release liner, or where the antioxidant is not in the matrix layer as claimed) can potentially reduce infringement risk against claim 9 even if the backing/adhesive/release elements exist.
5) The polymethacrylate requirement is a distinct claim path
Claim 6 requires:
- active: 7–40 wt%, free base
- polymer: 10–30 wt% polymethacrylate or acid addition salt
- antioxidant: 0.05–0.3 wt% α-tocopherol
This is the most mechanically specific claim in your excerpt and is likely the strongest hook for competitors who attempt to substitute polymer classes. If a product uses different polymers (not polymethacrylate) for the relevant fraction, it may avoid claim 6 while still potentially remaining within claim 1 or claim 7 if other windows and components match.
What is the claim construction risk profile for competitors?
Using your claim text as the constraint set, risk typically concentrates where products:
- use the same active (including free base vs salt form),
- include an antioxidant at 0.01–0.5 wt%, and
- use transdermal patches with conventional backing/adhesive/release liner structures, and/or
- place antioxidant in a polymer matrix layer consistent with claim 9.
Practical infringement hotspots by formulation category
| Competitor design choice |
Likely exposure |
| Use the same active, even if the salt form differs (but within “free base or acid addition salt”) |
High for claims 1 and 7 because claim language permits both forms |
| Use any antioxidant in 0.01–0.5 wt% |
High for claims 1 and 7 even if antioxidant identity differs |
| Use α-tocopherol at 0.05–0.3 wt% with polymer loading including polymethacrylate |
High for claim 6 |
| Use patch with backing + adhesive + release liner and a composition matching claim 7 |
High for claims 7 and 8 |
| Match claim 9’s internal layer arrangement (matrix with active+antioxidant; adhesive positioned as recited) |
High specifically for claim 9 |
What does the transdermal device claim scope cover beyond the composition?
From your excerpt, the transdermal claims are not limited to a specific patch thickness, release rate, or manufacturing method. They are limited by:
- the presence of a pharmaceutical composition that falls within claim 7, and
- conventional transdermal component types and their relative placement (especially claim 9).
That means the device scope is likely broad for patch variants, as long as the antioxidant and active weight fractions fall inside the claimed ranges and the adhesive/release liner/backing architecture matches.
Claim 7 baseline device scope
A “transdermal device comprising” a pharmaceutical composition with:
- active: 1–40 wt% (free base or acid addition salt)
- antioxidant: 0.01–0.5 wt%
- diluent/carrier: present
- weight percents based on total composition
Claim 8 adds conventional device elements
Requires:
- backing layer (support)
- adhesive for contacting and fixing composition to backing
- release liner releasably contacting adhesive
Claim 9 adds a specific layer stack
Requires:
- backing layer
- layer comprising active + antioxidant in polymer matrix
- release liner
- adhesive layer between polymer-matrix layer and release liner, releasably fixing to skin
How does the patent landscape look in the US around this family?
No US landscape can be completed from the claim text alone. A credible landscape requires patent bibliographic identifiers tied to US 6,316,023’s patent family, assignee, related continuations/divisionals, and any reissues or expiries, plus citation data and prosecution history. Your prompt provides claim text but does not provide:
- the assignee/applicant name,
- publication numbers,
- earliest priority date,
- filing date,
- related US family members,
- cited references or forward citations,
- whether the compound corresponds to a named marketed product.
Without those, any landscape statement would be speculative and not suitable for high-stakes R&D or investment decisions.
What diligence steps determine freedom-to-operate from these claims?
A legal-grade assessment of whether a candidate product infringes US 6,316,023 should map the product’s formulation and device layer stack directly to claim elements:
- Active form and wt%
- Confirm whether the product’s (S)-active is present as free base or acid addition salt, and whether its wt% in the pharmaceutical composition falls within the relevant ranges (claims 1/7: 1–40; claim 6: 7–40).
- Antioxidant presence and wt%
- Quantify antioxidant content to confirm whether it is within 0.01–0.5 (claims 1/7) and whether it overlaps 0.05–0.2 and/or 0.1–0.15 (claims 4/5).
- Antioxidant identity
- If asserting claim 2 or 3 risk, verify whether the antioxidant is one of the listed species or is α-tocopherol / ascorbyl palmitate.
- Specific polymer and α-tocopherol requirements (claim 6)
- Confirm whether polymethacrylate is present in the recited fraction (10–30 wt%) and whether α-tocopherol is present at 0.05–0.3 wt%.
- Transdermal architecture mapping (claims 7–9)
- Confirm that the patch includes backing layer, adhesive, and release liner (claim 8).
- For claim 9, confirm that the antioxidant and active sit together in the recited polymer matrix layer and that the adhesive layer sits between that matrix layer and the release liner in the patch stack.
Key Takeaways
- US 6,316,023 claims formulation-and-device-including antioxidant protection around (S)-N-ethyl-3-[(1-dimethylamino)ethyl]-N-methylphenyl carbamate using specific antioxidant dose windows (0.01–0.5 wt% baseline; narrower ranges in dependents) and a transdermal layered architecture (backing/adhesive/release liner; tighter placement in claim 9).
- The broadest hooks are claims 1 and 7 (active 1–40 wt% and antioxidant 0.01–0.5 wt%).
- The most specific hook is claim 6, requiring α-tocopherol plus polymethacrylate (or acid addition salt as recited) at defined wt% ranges.
- A completed US “patent landscape” cannot be produced from the claim excerpt alone because it depends on bibliographic family data, assignee and priority chain, and citation/forward-citation mapping to identify relevant competitors and blocking patents.
FAQs
-
Which claims are the broadest for product coverage?
Claims 1 (pharmaceutical composition) and 7 (transdermal device comprising the composition) because both allow active 1–40 wt% and antioxidant 0.01–0.5 wt% with conventional carrier language.
-
How can a formulation avoid the antioxidant-related claim elements?
By keeping antioxidant content outside the recited 0.01–0.5 wt% (and related narrower windows tied to dependent claims) or by ensuring the product does not meet the dependent claim conditions tied to α-tocopherol and/or identity lists.
-
What makes claim 6 strategically important?
It ties infringement to a specific combo: high active loading (7–40 wt%), polymethacrylate fraction (10–30 wt%), and α-tocopherol at 0.05–0.3 wt%.
-
Do the transdermal device claims require specific manufacturing steps?
No specific steps appear in the claim text you provided. Scope is driven by composition inclusion and patch structural elements (especially the layer arrangement in claim 9).
-
Can using a different antioxidant avoid infringement entirely?
It can avoid claims that depend on antioxidant identity (claims 2 and 3), but it does not automatically avoid claims 1 and 7 because those treat antioxidant identity generically while requiring only the antioxidant dose window.
References
[1] Provided claim text in user prompt for US Drug Patent 6,316,023 (claims 1–9 as quoted).
