Details for Patent: 4,801,587

Summary for Patent: 4,801,587

Title:	Impotence ointment
Abstract:	An ointment for relieving impotence. The ointment generally consists of a primary agent, a carrier, and a base, and is applied directly to the penis. The primary agent is a vasodilator selected from the group consisting of papaverine, hydralazine, sodium nitroprusside, phenoxybenzamine and phentolamine. The carrier is used to assist absorption of the primary agent through the skin around the penis. When the primary agent enters the corpora cavernosa within the penis, it causes dilation of the corpora, resulting in an erection.
Inventor(s):	Gene Voss, Allen C. Eichler
Assignee:	Individual
Application Number:	US07/020,544
Patent Claim Types: see list of patent claims	Use; Composition;

United States Patent 4,801,587 Claim Scope, Coverage Boundaries, and U.S. Patent Landscape for Topical/Local Vasodilator Treatments of Erectile Impotence

Executive summary: U.S. Patent 4,801,587 claims erectile-impotence relief methods built around (i) a vasodilator in an ointment at 1–5% by weight, (ii) topical local delivery to skin around the penis (including glans) using a base that does not require a specific base identity in claim 1, with DMSO (or dimethyl sulfoxide equivalents) as absorption-assistance in certain claims, (iii) a two-step “carrier-only then primary-agent ointment” topical regimen in claims 3–5, (iv) an urethral catheter + tube extrusion delivery architecture in claims 6–9, and (v) a surgical fibrous sheath partial removal step paired with topical vasodilator ointment in claims 10–12. The claim set is narrow in dose range and partly narrow in delivery route, with functional room created by the open-ended “selected from the group” vasodilators and the less-specific “base” language. The practical infringement risk for a generic or alternative product concentrates on whether the accused method includes all method steps plus the 1–5% weight vasodilator and the specific delivery route (topical around penis/glans, urethral catheter extrusion, or post-sheath surgery) that maps to independent claim theory.

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What is the exact claim scope of U.S. Patent 4,801,587 for impotence relief?

U.S. Patent 4,801,587 contains one independent method claim (claim 1) plus dependent method claims (2–12). The core coverage is a method-of-treatment defined by a delivery regimen and an ointment composition used during that regimen.

Claim 1: single-step topical ointment applied to skin around the penis

Independent claim 1 recites:

• Method: “relieving impotence”
• Single step: “applying an ointment to the skin around the penis”
• Ointment comprises:
  • a primary agent that is a vasodilator selected from:
    • papaverine
    • hydralazine
    • sodium nitroprusside
    • phenoxybenzamine
    • phentolamine
  • primary agent amount: 1–5% by weight
  • dimethyl sulfoxide for assisting absorption through the skin
  • a base

Key scope points for claim 1

• Route is mandatory: “skin around the penis.” This limits coverage compared with claims that use intrarectal, systemic, or injectable approaches.
• Dose window is mandatory: 1–5% by weight of the selected vasodilator.
• Absorption-assist is mandatory: dimethyl sulfoxide is expressly required “for assisting absorption.”
• Base is generic: “a base” is not restricted to a specific base type (no identity constraint in claim 1).

Claim 2: glans-specific topical location

• Narrows claim 1 by requiring ointment application to the glans portion of the penis.

Claims 3–5: two-ointment topical regimen with removal

Independent claim 3 covers a multi-step topical sequence:

1. Apply first ointment containing only a carrier for assisting absorption of the primary agent through the skin.
2. Remove the first ointment after a short period of time.
3. Apply second ointment containing:
   • the same “primary agent” vasodilator list
   • primary agent amount 1–5% by weight

Claim 4: carrier is dimethoxy sulfoxide (spelling “dimethoxy” appears in the claim text you provided).
Claim 5: both ointments applied to the glans.

Scope implications

• Claim 3 requires a two-stage process and a removal step.
• The first ointment contains no primary agent, only a carrier that facilitates absorption of the later primary agent.
• Claim 4 narrows further by tying carrier to a specific sulfoxide derivative (as written).

Claims 6–9: urethral catheter delivery by extruding ointment into the urethra

Independent claim 6 recites:

• Place a catheter within the urethra
• Catheter is in fluid communication with a tube
• Tube contains an ointment comprising:
  • primary vasodilator in 1–5% by weight
  • base
• Squeeze the tube to extrude ointment into catheter and then into urethra
• Delivery outcome is within the method framing “relieving impotence”

Claim 7: primary agent must be one of the enumerated vasodilators.
Claim 8: ointment further includes a carrier for assisting absorption through the urethral wall.
Claim 9: carrier is dimethoxy sulfoxide.

Scope implications

• This is a distinct delivery pathway from claim 1: urethral installation, not external skin application.
• Claim 6 does not expressly require DMSO/dimethoxy sulfoxide by name in the independent claim; it requires “base,” and optional absorption carrier is added only in claim 8.
• The mandatory elements are procedural: catheter placement + extrusion by squeezing.

Claims 10–12: surgical fibrous sheath modification plus topical vasodilator ointment

Independent claim 10 recites:

1. Surgically remove a portion of the fibrous sheath surrounding the corpora cavernosa
2. Apply an ointment to the skin around the penis comprising:
   • primary vasodilator (1–5% by weight)
   • base

Claim 11: primary agent restricted to the listed vasodilators.
Claim 12: ointment further comprises a “carrier for missing absorption” through the wall of the urethra (as written, likely “proper” or “assisting” but constrained text is what controls claim language).

Scope implications

• Claim 10 ties treatment to a specific surgical predicate (sheath removal) plus topical delivery.
• External topical route is the same as claim 1, but the claim requires an additional surgical step.

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What parts of the claim are most infringement-relevant (dose, carrier, route, sequence)?

1–5% by weight vasodilator concentration

• This concentration window is the tightest quantitative constraint across the claim set.
• Infringement requires that the accused ointment (as used in the method) has the vasodilator at within 1–5% w/w.

Delivery route differentiates independent claim theories

• Claim 1/2/10: external application “to skin around the penis,” including glans for claim 2.
• Claim 3/4/5: external application, but two-stage regimen with first carrier-only removal.
• Claim 6–9: urethral installation via catheter and tube extrusion.
• Claim 10–12: requires surgery then external ointment.

Sulfoxide derivatives as absorption aids

• Claim 1 explicitly requires dimethyl sulfoxide (DMSO).
• Claims 4 and 9 specify dimethoxy sulfoxide (as written).
• Claims 8 and 12 require a urethral-wall absorption carrier, but only claim 9 and claim 12 fix it by name per your text.

Sequence matters

• Claim 3 requires: apply carrier-only ointment → remove after short period → apply primary-agent ointment.
• Claim 6 requires squeezing/extrusion mechanics to move ointment through catheter into urethra.

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How many vasodilator actives does the patent cover, and how broad is the “selected from the group” language?

Across claims where the vasodilator is specified, the primary agent is “selected from” five enumerated vasodilators:

1. papaverine
2. hydralazine
3. sodium nitroprusside
4. phenoxybenzamine
5. phentolamine

Coverage consequence

• The patent is broad as to which listed vasodilator is used, but narrow versus any vasodilator not in the list.
• Substituting a non-enumerated vasodilator is outside the enumerated group on a literal reading of claims that require this limitation.

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What formulations are protected by U.S. Patent 4,801,587 (ointment composition elements)?

While this patent is method-focused, the method claims tightly tie the ointment to composition elements. The protected formulation features by claim cluster are:

Topical ointment (Claim 1 + Claim 2)

• vasodilator in 1–5% w/w
• dimethyl sulfoxide absorption-assist
• base (unspecified)
• applied to skin around penis (glans in claim 2)

Two-ointment regimen (Claim 3–5)

• first ointment: carrier only (no primary agent) to assist absorption
• second ointment: vasodilator 1–5% w/w plus base
• optional: carrier identity narrowed to dimethoxy sulfoxide (claim 4)
• optional: application to glans (claim 5)

Urethral catheter + tube extrusion ointment (Claim 6–9)

• ointment contains vasodilator 1–5% w/w and base
• optional absorption carrier added in claim 8 (carrier type narrowed in claim 9)

Post-surgical sheath removal + topical ointment (Claim 10–12)

• surgical step is mandatory
• ointment: vasodilator 1–5% w/w and base
• optional urethral-wall absorption carrier in claim 12 (per provided text)

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What generic entry risks exist for topical erectile-impotence vasodilator ointments under this patent?

Risk analysis is driven by whether the accused product’s labeled use or commercially practiced method maps to a claim’s step-by-step limitations:

Higher risk profiles

• Products and prescribing instructions that promote applying an ointment containing one of the enumerated vasodilators at 1–5% w/w with DMSO as the absorption assistant to the skin around the penis.
• Regimens that implement the two-stage carrier-only application followed by vasodilator ointment with removal timing.
• Devices and kits that combine a catheter and tube extrusion of a vasodilator ointment at 1–5% w/w into the urethra.

Lower risk profiles (relative)

• Products using vasodilators outside the enumerated list.
• Formulations using a different absorption enhancer than dimethyl sulfoxide where claim 1 is asserted.
• Methods that avoid the specified routes and procedural mechanics (external skin vs urethral catheter extrusion vs post-surgical sheath removal).

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When does this patent lose exclusivity in the U.S., based on the grant date and typical term rules?

No term-extension data, priority/filing date, patent term adjustment (PTA), or terminal disclaimer information is provided in the input. Without those facts, a precise “expiration date” cannot be calculated from the grant number alone.

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What Orange Book status applies to U.S. Patent 4,801,587?

U.S. Patent 4,801,587 appears in the input as a drug patent number, but no Orange Book listing, NDA/BLA association, or FDA reference product is provided. Without that linkage, Orange Book status and FDA exclusivity tie-in cannot be determined from the information given.

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What does the claim set imply about patent enforceability against alternative delivery systems?

The patent claims are structurally tied to:

• ointment applied to particular locations (skin around penis or glans),
• a defined concentration band,
• specific absorption-assisting sulfoxides in certain claims,
• either catheter extrusion mechanics (urethral route) or a surgical predicate (sheath removal).

That makes “workaround by route change” potentially effective:

• Switching from external topical to systemic delivery avoids the topical “skin around the penis” limitation.
• Avoiding urethral catheter extrusion avoids claim 6’s procedural delivery steps.
• Avoiding surgical sheath removal avoids claim 10’s predicate.

Workarounds via formulation changes are more constrained:

• For claim 1, replacing DMSO with another absorption enhancer risks non-infringement on the explicit “dimethyl sulfoxide” element.
• For concentration, moving out of 1–5% w/w may move outside literal coverage, though infringement doctrine beyond literal reading depends on claim construction and equivalents, which are not addressable from the provided text alone.

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Related U.S. patent landscape questions that typically determine freedom-to-operate

This section outlines the specific neighboring IP axes that normally determine whether 4,801,587 is a dominant barrier, but the underlying dataset (other patents, litigation, assignments, and related patents) is not included in the input, so no enumerated landscape list can be produced here.

Common adjacent patent clusters to check

• earlier foundational patents on topical vasodilator ointments and DMSO-assisted absorption for impotence/ED
• device patents for catheter-based intraurethral delivery systems
• combination therapy patents pairing PDE5 inhibition or other ED agents with topical vasodilator delivery
• formulation patents defining bases that improve topical spread, residence time, or penetration
• method-of-treatment patents that differ by dose ranges, routes (intracavernosal vs topical vs intraurethral), or surgical predicates

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Key claim-scope matrix for U.S. Patent 4,801,587 (based on provided claim text)

Claim	Independent/Dependent	Core method step(s)	Route/location	Vasodilator list	Concentration	Absorption-assist requirement
1	Independent	Single step applying ointment	Skin around penis	Papaverine, hydralazine, sodium nitroprusside, phenoxybenzamine, phentolamine	1–5% w/w	DMSO required
2	Dependent	Apply ointment as in claim 1	Glans portion	Same as claim 1	1–5% w/w	DMSO (via claim 1)
3	Independent	Apply carrier-only ointment then remove, then apply vasodilator ointment	Skin around penis	Same list	1–5% w/w (second ointment)	Carrier only first; second uses carrier implicitly
4	Dependent	Carrier identity for claim 3	Skin around penis	Same list	1–5% w/w (second ointment)	Carrier is dimethoxy sulfoxide (as written)
5	Dependent	Apply both ointments to glans	Glans	Same list	1–5% w/w (second ointment)	Carrier via claim 4/3
6	Independent	Catheter in urethra, tube contains ointment, squeeze extrudes into catheter and urethra	Urethra	Same list	1–5% w/w	Absorption carrier optional (claim 8)
7	Dependent	Vasodilator identity for claim 6	Urethra	Same list	1–5% w/w	Per claim 6
8	Dependent	Add absorption carrier for urethral wall	Urethra	Same list	1–5% w/w	Carrier required (identity in claim 9)
9	Dependent	Carrier identity for claim 8	Urethra	Same list	1–5% w/w	Carrier is dimethoxy sulfoxide (as written)
10	Independent	Surgically remove portion of fibrous sheath + apply ointment	Skin around penis	Same list	1–5% w/w	DMSO not stated; claim 12 addresses “carrier”
11	Dependent	Vasodilator identity for claim 10	Skin around penis	Same list	1–5% w/w	Per claim 10
12	Dependent	Add “carrier for missing/assisting absorption” through urethral wall	Post-surgery + topical	Same list	1–5% w/w	Carrier required (identity not specified in provided text)

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Key Takeaways

• The patent’s core claim 1 requires: external topical application around the penis, using a listed vasodilator at 1–5% w/w, with dimethyl sulfoxide as a specified absorption-assist plus an unspecified base.
• Claim 3 creates separate coverage for a two-stage topical regimen with carrier-only application followed by removal, then application of a 1–5% w/w vasodilator ointment.
• Claims 6–9 shift to urethral delivery, requiring catheter placement and tube-squeezing extrusion into the urethra, with a urethral-wall absorption carrier required in claim 8 and narrowed in claim 9.
• Claim 10 adds a surgical predicate (removal of a portion of the fibrous sheath surrounding the corpora cavernosa), then pairs it with the same topical 1–5% w/w vasodilator ointment concept.
• Practical infringement risk is driven by whether an accused method exactly matches the route, sequence, and 1–5% w/w concentration, and whether it uses DMSO where claim 1 requires it.

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FAQs

1. Does U.S. Patent 4,801,587 cover systemic erectile dysfunction treatments (oral tablets) using papaverine or phentolamine?
2. Can a method using a vasodilator not listed in the claims avoid literal infringement of claims 1, 3, 6, and 10?
3. If an ointment contains the listed vasodilator at 0.8% or 6% w/w, does it fall outside the patent’s claim concentration window?
4. Does claim 6 require dimethyl sulfoxide in the urethral ointment, or only a base plus optional absorption carrier?
5. How does adding a new surgical step or using a different catheter delivery device affect risk under claims 6 and 10?

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References

No citable sources were provided in the prompt beyond the claim text of U.S. Patent 4,801,587.

Drugs Protected by US Patent 4,801,587

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 4,801,587

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	1320442