United States Patent 3,862,321 Scope and Claims Analysis (Active Ingredient Variants and Local Anesthesia Method Claims)

US Drug Patent US 3,862,321 is a claims-focused protection package centered on a chemical series defined by a “structural formula” (claim 1), then narrowed by specific active-ingredient substitutions (claims 2–8) and matched local-anesthesia use (claims 9–16). The patent’s enforceable surface is concentrated on (i) composition claims that specify the active ingredient as one of several named derivatives and (ii) method claims that cover applying a “locally anesthetizing amount” of those same derivatives to induce local anesthesia in animals.

What does US 3,862,321 claim 1 cover, and how broad is the “structural formula” anchor?

Claim 1’s role in determining claim breadth

The dependent claims you provided (claims 2–8 for composition; claims 9–16 for method) repeatedly use “as defined by claim 1.” That language means the scope of every dependent claim is capped by the boundaries of claim 1’s structure definition and any limitations inside it.

Practically, this creates a two-layer claim architecture:

Layer A (structural anchor): claim 1 defines the permitted chemical class by a structural formula.
Layer B (variant selection): dependent claims identify which specific substitution patterns from that class are included as active ingredients.

Interpretation for landscape work

For freedom-to-operate and licensing triage, the key point is that claims 2–8 and 10–16 do not create new chemistry outside claim 1. They select active ingredients from a claim-1-defined set. If a competitor’s compound falls outside claim 1’s structural envelope, the dependent claims fall with it even if the substitution resembles one of the listed actives.

Actionable consequence: any patentability or infringement analysis must first map each candidate compound to the claim-1 structure definition.

What compositions are covered by US 3,862,321 claims 2–8 (active ingredient substitution scope)?

Composition claims list: seven specific actives

Claims 2–8 are “composition as defined by claim 1” with a specified active ingredient. Your list identifies these covered actives:

Claim	Active ingredient (as recited)	Scope effect
2	2-diethylamino-2'',6''-n-butyroxylidide	specific derivative captured inside claim-1 structural class
3	2-(N-ethyl-n-propylamino)-2'',6''-n-butyroxylidide	narrows to one substitution pattern
4	2-diethylamino-2'',6''-n-valeroxylidide	substitutes side chain length variant
5	2-pyrrolidino-2'',6''-n-butyroxylidide	changes amine identity to cyclic pyrrolidine
6	2-(N-ethyl-n-butylamino)-2'',6''-n-butyroxylidide	expands N-alkyl chain variant
7	2-dimethylamino-2'',6''-caproylxylidide	changes both amine substitution and acyl/xylidide region
8	2-pyrrolidino-2'',6''-n-valeroxylidide	pyrrolidine plus valeroyl variant

How to read the substitution logic

The listed actives show the series is built around:

Amine substituent variations: diethylamino, dimethylamino, N-ethyl-n-propylamino, N-ethyl-n-butylamino, and pyrrolidino.
Acyl/side-chain length variations: n-butyroxy (butyroxylidide), n-valero (valeroxylidide), caproyl (caproylxylidide).

Claim strength implications

Because the composition claims are dependent on claim 1 and also explicitly name the active ingredient, they are best treated as:

High specificity: infringement is most likely when a formulation contains one of these exact actives (or a chemical equivalent that still meets the chemical definition of the recited compound).
Lower coverage against “near neighbors”: if an active ingredient differs in amine identity, N-alkyl length, or the acyl component outside the listed options, the claim may not reach it unless claim 1’s structure still encompasses that alternate.

What does US 3,862,321 claim 9 cover: a local anesthesia method for animals?

Method claim 9’s operative language

Claim 9 defines:

“A method of inducing local anesthesia in animals”
by applying to the area of the body to be anesthetized
“a locally anesthetizing amount”
of a compound having the “structural formula” (again pointing back to claim 1).

This is a classic use claim with three pillars:

Anatomical application: “to the area of the body to be anesthetized”
Dosage sufficiency: “a locally anesthetizing amount”
Active chemical requirement: compound must fit the claim 1 structural definition

Practical enforcement angle

Method claims tend to be harder to enforce than composition claims when products are sold and handled clinically, but they can still be asserted where evidence shows direct use of the claimed compound in the claimed manner.

For landscape purposes, method claim 9 can be used to:

attack a party whose product label, IFU, or clinical use instructions align with “inducing local anesthesia in animals,” and
build a case using sales, labeling, and use evidence, even if formulations are not directly “composition” asserted.

Which specific actives are protected by the method claims 10–16?

Claims 10–16 mirror the composition list by specifying the compound used in claim 9. The covered actives are the same set as claims 2–8, with small formatting differences in your excerpt (for example, “2'',6''-butyroxylidide” vs “2'',6''-n-butyroxylidide”).

Claim	Method active ingredient (as recited)	Coverage scope effect
10	2-diethylamino-2'',6''-n-butyroxylidide	direct method embodiment
11	2-(N-ethyl-n-propylamino)-2'',6''-n-butyroxylidide	direct method embodiment
12	2-diethylamino-2'',6''-n-valeroxylidide	direct method embodiment
13	2-pyrrolidino-2'',6''-n-butyroxylidide	direct method embodiment
14	2-(N-ethyl-n-butylamino)-2'',6''-butyroxylidide	direct method embodiment (note: “n-” formatting variance)
15	2-dimethylamino-2'',6''-caproylxylidide	direct method embodiment
16	2-pyrrolidino-2'',6''-n-valeroxylidide	direct method embodiment

Method claim breadth

As with composition claims, the key determinant is claim 1’s structural scope. These dependent claims do not create an unlimited set of anesthetics. They are limited to the enumerated actives, each of which must satisfy the claim-1-defined structural requirements.

How does the claim architecture affect infringement risk: composition vs method?

Composition claims (2–8)

Best suited for product-based disputes: if a formulation contains one of the recited active ingredients, the composition claims are a direct fit.
If a competitor uses a different derivative not falling within claim 1 or not matching the specific recited active ingredients in claims 2–8, infringement risk drops unless the claim-1 envelope still covers it.

Method claims (9–16)

Tied to use: “inducing local anesthesia in animals” by application to a body area.
Even where a product contains a covered compound, method infringement can depend on demonstrated use practices aligned with the claim.

Combined value

The patent’s practical enforceability is strongest where both conditions hold:

the active ingredient is one of the enumerated derivatives; and
the product is used (or intended to be used) to induce local anesthesia in animals by local application.

What adjacent patent landscape questions are answered by US 3,862,321’s claim language?

1) Does the patent cover “analogs” or only named derivatives?

Based on your excerpts, the only explicit chemical coverage in dependent claims is the named set of actives in claims 2–8 and 10–16. If claim 1 defines a broader structural genus, the patent may also cover other substitution variants that still satisfy claim 1’s structure. But without claim 1 text, the exact genus-to-enumerated relationship cannot be quantified from your provided material alone.

2) Are manufacturing changes a defense?

Manufacturing process is not recited in the dependent claims you provided. The claim focus is on the compound itself (for composition) and use/application (for method). Process changes that do not change the chemical identity are unlikely to avoid claims that are compound-identity driven.

3) Does salt formation matter?

Your excerpt does not mention salts, hydrates, polymorphs, particle size, or formulation excipients. If claim 1 or the full specification addresses salt forms, they may broaden product coverage. With only dependent-claim text, salt-specific breadth cannot be determined here.

Where does exclusivity end in the United States for a patent like 3,862,321?

Patent term mechanics (high-level)

US utility patent exclusivity runs to the patent’s expiration date, subject to any patent term adjustments or extensions. Determining the exact expiration date for US 3,862,321 requires the patent’s grant and any PTA/adjustment data not included in your excerpt.

How many patent claim “targets” does US 3,862,321 create across actives and uses?

From the claims you supplied:

Composition targets: 7 enumerated active ingredients (claims 2–8)
Method targets: 7 corresponding active ingredients (claims 10–16)
Shared claim-1 dependency: all targets sit inside the claim-1 structural definition

Total distinct enumerated active embodiments across the excerpted claims: 7 actives supported by two use modes (composition and animal local anesthesia method).

Key Takeaways

US 3,862,321 is structured around a claim-1 structural formula that anchors both composition and method claims.
Dependent claims enumerate seven specific active ingredient derivatives, each captured as both:
- a composition (claims 2–8) and
- a local anesthesia method for animals via local application (claims 9–16).
Enforceability concentrates on whether a product contains one of the enumerated actives and, for method assertions, whether use aligns with animal local anesthesia by local application.
Any claim-1 structural boundaries are decisive for coverage beyond the enumerated compounds, but those boundaries are not present in the excerpt you provided.

FAQs

Do US 3,862,321 claims cover human local anesthesia or only animals?
Based on claim 9’s wording, the method is limited to “animals.”
Can a formulation avoid infringement by changing excipients?
If the active ingredient remains one of the covered compounds within the claim-1 structural scope, excipient changes alone do not remove composition coverage based on dependent claim language.
Does US 3,862,321 protect only the exact named compounds or also derivatives?
Dependent claims expressly name the compounds; broader derivative coverage depends on claim 1’s structural scope.
Are method claims enforceable without showing how the product was manufactured?
The method claims you provided focus on application and the locally anesthetizing amount, not manufacturing steps.
What is the main difference between claims 2–8 and claims 9–16 for legal strategy?
Claims 2–8 target compound-in-formulation, while claims 9–16 target the local anesthesia use in animals.

References

United States Patent 3,862,321 (claim text provided in prompt).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	193840	⤷ Start Trial
Austria	319205	⤷ Start Trial
Australia	3709971	⤷ Start Trial
Australia	468489	⤷ Start Trial
Belgium	776656	⤷ Start Trial
Brazil	7108466	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 3,862,321

Summary for Patent: 3,862,321