United States Patent 9,480,652: Claims, Scope, Expiration, and Patent Landscape

U.S. Patent No. 9,480,652 protects a steam-sterilizable aerosol valve and related microfoam-generation devices and methods for sclerotherapy. Its central inventive combination is a polymeric aerosol valve with a specific gas-metering geometry and high-temperature material properties. The patent does not broadly claim polidocanol, sodium tetradecyl sulfate, or microfoam therapy independent of that valve architecture.

The strongest practical coverage is directed to an aerosol valve that combines:

A valve body with external slots.
A valve insert with bottom-formed gas channels creating two internal gas-metering slots.
A stem valve.
Polymer components with a heat-deflection temperature of 200-275°C at 1.8 MPa stress.
Use of the valve in producing sclerotherapy microfoam.

What does U.S. Patent 9,480,652 cover?

The patent covers an integrated valve-and-microfoam system rather than a drug composition. Independent claims 1, 18 and 27 establish three coverage groups.

Claim group	Claims	Subject matter	Main limitation
Aerosol valve	1-17, 26	Steam-sterilizable valve	Specific valve geometry and polymer properties
Microfoam production method	18-25	Production of sclerotherapy microfoam	Requires the claimed aerosol valve
Microfoam device	27-29	Pressurized device for producing microfoam	Requires the claimed valve and system architecture

The claims use narrow structural language. A competing device generally must satisfy every limitation of the relevant claim to create literal infringement risk.

What is the scope of independent claim 1?

Claim 1 is the principal valve claim. It requires all of the following:

A steam-sterilizable aerosol valve.
A valve body with external slots.
A valve insert.
Gas channels formed on the bottom of the insert.
Two internal gas-metering slots created by those channels.
Communication between the internal metering slots and external slots when the insert is preassembled into the valve body.
A stem valve.
The valve body, insert and stem valve made from polymeric material.
Each polymeric component having an HDT at 1.8 MPa of 200-275°C.

The claim is narrower than a generic claim to a heat-resistant aerosol valve. The internal and external slot relationship is central. A valve using a different gas-metering configuration, such as drilled passages, a single metering channel, or an insert that does not create two internal slots, may avoid literal infringement even if it uses the same polymer.

The phrase "when preassembled into the valve body" also makes the assembled relationship relevant. The claim is directed to the functional geometry of the inserted valve component, not merely to an insert considered in isolation.

How does claim 1 define the material requirement?

The HDT limitation is measured at 1.8 MPa and requires a range of 200-275°C. This limitation excludes conventional low-temperature plastics commonly used in aerosol valves.

The material limitation applies collectively to the valve body, insert and stem valve. Because the claim states that these components "consist of polymeric material," the claim may be interpreted as materially limiting the relevant components to polymeric construction, subject to standard claim-construction treatment of additives, fillers and processing aids.

The claim does not require the components to be made from the same polymer. That narrower requirement appears in claim 2.

Which dependent claims create the strongest design-around constraints?

Claims 2-15 add material-property limitations. Claims 16 and 17 add narrower polymer classes or chemical structures. Claim 26 specifically requires PPSU.

Claims	Limitation	Commercial significance
2	Same material for body, stem and insert	Narrows material uniformity
3-4	Body HDT of 200-250°C, including 200-210°C	Targets a narrower thermal-performance window
5-6	Tg of 200-330°C, including 210-230°C	Adds glass-transition control
7-8	24-hour moisture absorption below 0.75%, preferably below 0.6%	Addresses sterilization and dimensional stability
9-10	Saturated liquid water uptake below 3%, preferably below 2.5%	Limits swelling and performance changes
11-12	Izod impact strength at least 0.8 J/cm, preferably above 1.0 J/cm	Addresses fracture resistance
13-14	Tensile stiffness below 4.0 GPa, preferably below 3.0 GPa	Excludes excessively rigid polymers
15	PEI, PES, PPSU, PI or LCP	Defines listed polymer classes
16-17	Specific polymer structures or copolymers	Potentially narrower species claims
26	PPSU valve-body material	Provides an express PPSU fallback claim

The most commercially relevant fallback claims are claims 15 and 26. Claim 26 is narrower than claim 15 because it requires PPSU, but it may be easier to prove if the accused product’s material is identified in specifications, regulatory filings or supplier records.

What is the significance of claims 18-25 for sclerotherapy microfoam?

Claims 18-25 extend the patent from the valve itself to a method of producing microfoam for sclerotherapy of blood vessels.

Claim 18 requires:

A physiologically acceptable, blood-dispersible gas.
A container holding an aqueous sclerosant liquid.
Release of the gas-liquid mixture.
Formation of microfoam upon release.
The container being equipped with the claimed steam-sterilizable valve.

Claim 19 limits the sclerosant to polidocanol or sodium tetradecyl sulfate. Claim 20 narrows polidocanol concentration to 0.25-5% vol/vol.

The claims also regulate process conditions and foam characteristics:

Claim	Limitation
21	Pressure of 800 mbar to 4.5 bar gauge
22	Preferred pressure of 1-2.5 bar gauge
23	Bubble-size distribution, including more than 75% of bubbles between 30 and 280 micrometers
24	Foam density of 0.07-0.19 g/ml
25	Half-life of at least two minutes

These limitations create a relatively narrow process claim. A product using polidocanol but generating foam through a different valve, at a different pressure, or outside the claimed bubble-size and density ranges may fall outside one or more claims.

The method claims are commercially important because they connect the valve to a finished sclerotherapy product. They do not independently cover every use of polidocanol or every method of making foam.

What do claims 27-29 protect?

Claim 27 is a second independent valve claim. It substantially repeats the core architecture of claim 1, including:

External slots in the valve body.
A bottom-channel insert.
Two internal gas-metering slots.
A stem valve.
Polymer components having an HDT of 200-275°C at 1.8 MPa.

Claims 28 and 29 add the broader device system:

A housing.
A pressurizable chamber containing sclerosant solution.
A pathway and outlet orifices.
A mechanism that opens and closes the pathway.
An inlet for pressurized, blood-dispersible gas.
Foaming elements in the outlet pathway.
Passages with cross-sectional dimensions of 0.1-30 micrometers.
Foam density of 0.07-0.19 g/ml.
Foam half-life of at least two minutes.

Claims 27-29 therefore combine valve construction with the full foam-generating device. They are potentially useful against an integrated single-use canister or dispenser that incorporates the claimed valve and foaming pathway.

What polymer materials are covered?

Claim 15 identifies five material classes:

Polyetherimide, or PEI.
Polyethersulfone, or PES.
Polyphenylsulfone, or PPSU.
Polyimide, or PI.
Liquid crystal polymer, or LCP.

The material must also satisfy the relevant thermal and mechanical properties in the applicable claim. Merely using PEI, PES, PPSU, PI or LCP does not by itself establish infringement of claim 1.

The polymer-property limitations are important because the invention is directed to steam sterilization. Repeated autoclave exposure can cause deformation, hydrolysis, swelling, embrittlement or dimensional changes in conventional polymers. The claimed property profile attempts to balance:

High heat resistance.
Low water absorption.
Adequate impact strength.
Controlled stiffness.
Dimensional stability in the valve’s metering geometry.

A design using stainless steel, ceramic, glass or a polymer outside the claimed HDT range would present a direct noninfringement position against claim 1, assuming the other claims do not reach the design.

What is the likely patent expiration date?

U.S. Patent No. 9,480,652 issued on November 1, 2016. Its expiration is governed primarily by the 20-year term measured from the earliest effective nonprovisional U.S. filing date or applicable international filing date, subject to patent-term adjustment, terminal disclaimers and any patent-term extension.

The patent appears to belong to the generation of intellectual property supporting pressurized polidocanol microfoam products developed for sclerotherapy. Its ordinary statutory term is therefore expected to run into approximately 2029, although the exact expiration date must be taken from the USPTO patent-term and continuity records. An issued patent does not become enforceable indefinitely merely because it remains listed in commercial or regulatory materials.

What is the FDA and Orange Book relevance?

The patent is relevant to a drug-device combination involving polidocanol microfoam, including Varithena, which the FDA approved for the treatment of incompetent veins and associated varicose veins in the lower extremity [2].

The patent’s regulatory relevance comes from the valve and delivery system, not from ownership of polidocanol as an active pharmaceutical ingredient. FDA Orange Book listing can create a Hatch-Waxman litigation pathway if the patent is listed against an applicable approved drug product. A listed device or formulation patent can be relevant to an abbreviated new drug application only if it is properly listed and claims the approved product, formulation, method of use or relevant drug-delivery configuration.

The Orange Book status of U.S. Patent 9,480,652 should be checked against the specific NDA and listing history. A patent’s inclusion in FDA patent information does not establish validity or infringement. It can, however, support a Paragraph IV notice and potential litigation under 21 U.S.C. § 355(j).

Are biosimilar risks relevant?

Biosimilar risk is not the principal issue. Polidocanol is a synthetic small-molecule sclerosant, not a biologic. The relevant competitive pathway is an ANDA or, depending on product characteristics, a 505(b)(2) application.

The principal regulatory and commercial risks are:

Generic or follow-on polidocanol products.
Alternative foam-generation devices.
Hospital-compounded or physician-prepared foam.
Products using different aerosol valves.
Devices using nonsteam sterilization or a different sterilization architecture.
Products that use a different gas-liquid mixing mechanism.

Which companies could challenge the patent?

Potential challengers would include manufacturers of:

Polidocanol injectable products.
Sclerotherapy foam products.
Pressurized canisters.
Aerosol valves.
Medical packaging components.
Generic or follow-on venous-sclerotherapy products.

The strongest challenge would likely focus on claim construction and prior art relating to aerosol valves, autoclave-compatible polymers, gas metering slots and microfoam-generation devices.

Likely validity arguments

The principal validity issues are:

Obviousness under 35 U.S.C. § 103 based on combining known steam-resistant polymers with known aerosol-valve slot geometries.
Anticipation under 35 U.S.C. § 102 if a single reference discloses the claimed dual-slot insert and the specified HDT range.
Written-description and enablement issues concerning the full breadth of the polymer classes and property ranges.
Indefiniteness concerns involving measurement methods for HDT, moisture absorption, water saturation, Izod impact strength and tensile stiffness.
Claim-construction disputes over "formed on to the bottom," "two internal gas metering slots" and the required communication with external slots.

The property limitations may provide both patentability support and enforcement difficulty. They can distinguish prior art, but they require reliable testing under the specified standards and conditions.

What patent litigation and settlement issues matter?

The key litigation question is whether a competing product uses the same valve geometry and polymer profile. Product-level investigation should examine:

Valve-body drawings.
Insert geometry.
Number and location of metering slots.
Polymer supplier and grade.
HDT data at 1.8 MPa.
Steam-sterilization cycle.
Gas pressure.
Foam density and half-life.
Bubble-size distribution.
Sclerosant concentration.
FDA device and container descriptions.

A settlement could take several forms:

A delayed generic launch.
A license limited to a particular valve supplier.
A carve-out from a sclerotherapy method.
A covenant not to sue for a redesigned valve.
Supply-chain restrictions covering the valve rather than the drug.

No conclusion regarding a specific settlement, Paragraph IV notice or active infringement action should be drawn solely from the claim text. Those matters depend on current USPTO, FDA, PACER and court-docket records.

How strong is the patent estate?

The patent has moderate, targeted strength.

Factor	Assessment
Core technology	Narrowly defined valve and sterilization architecture
Product relevance	High where the marketed product uses the claimed dispenser
Composition-of-matter protection	None apparent from the claims provided
Method-of-use protection	Limited to microfoam production using the claimed valve
Design-around potential	Material, especially through different valve geometry or materials
Evidence burden	Significant for internal slot geometry and polymer properties
Regulatory leverage	Potentially meaningful if properly listed against an approved product
Generic vulnerability	Higher for products that avoid the patented valve while using the same sclerosant
Biosimilar exposure	Not applicable in the conventional sense

The claims are strongest against a vertically integrated product in which the valve, canister and microfoam process are supplied as one system. They are weaker against a competitor that sells polidocanol separately or uses an alternative foam-generation platform.

How does this patent compare with typical drug patents?

U.S. Patent 9,480,652 differs from a conventional pharmaceutical patent in three ways:

It does not claim the active ingredient itself.
It combines mechanical structure with polymer performance criteria.
Its method claims depend on use of the patented valve.

This creates a narrower exclusionary right than a composition patent but may provide meaningful lifecycle protection for a drug-device product. The patent is more vulnerable to engineering redesign than a valid composition-of-matter patent.

Key Takeaways

U.S. Patent 9,480,652 primarily protects a steam-sterilizable aerosol valve used to generate sclerotherapy microfoam.
Claim 1 requires a dual-slot gas-metering insert, external valve-body slots, a stem valve and high-HDT polymeric components.
Claims 15 and 26 identify PEI, PES, PPSU, PI and LCP, with claim 26 specifically directed to PPSU.
Claims 18-25 protect microfoam production only when the claimed valve is used.
Claims 27-29 cover an integrated pressurized microfoam device with defined foam passages and performance characteristics.
The patent does not independently claim polidocanol, sodium tetradecyl sulfate or all sclerotherapy microfoam.
The expected statutory term runs approximately into 2029, subject to the USPTO’s definitive term calculation.
The main design-around routes are alternative valve geometry, different materials, different sterilization methods and separate foam-generation mechanisms.
The primary competitive pathway is generic or follow-on small-molecule competition, not biosimilar competition.
Enforcement will depend heavily on access to valve drawings, polymer specifications and foam-performance testing.

Frequently Asked Questions

Does U.S. Patent 9,480,652 cover polidocanol itself?

No. The claims provided cover a valve, microfoam-generation method and device. Polidocanol appears only as a narrowing sclerosant limitation in claims 19 and 20.

Can a competitor avoid the patent by using a different polymer?

Potentially. A different polymer may avoid the claims if it does not satisfy the claimed HDT and related property limitations. The full valve geometry must also be analyzed.

Does the patent cover physician-made sclerotherapy foam?

Only if the foam is produced using a valve satisfying the relevant claims. The patent does not broadly cover every physician-made microfoam preparation.

Is PPSU automatically infringing under claim 26?

No. PPSU is necessary for claim 26, but the accused valve must also satisfy the incorporated limitations of claim 1, including the slot geometry and HDT range.

What is the most important evidence in an infringement investigation?

The most important evidence is the internal valve-insert design, polymer grade and test data for HDT at 1.8 MPa. Foam density, bubble-size distribution and pressure data are also important for claims 18-25 and 27-29.

References

United States Patent No. 9,480,652. (2016). Steam-sterilizable aerosol valve. U.S. Patent and Trademark Office.
U.S. Food and Drug Administration. (2013). Varithena (polidocanol injectable foam) prescribing information. FDA.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA.
U.S. Patent and Trademark Office. (2024). Manual of patent examining procedure: Patent term adjustment and patent term extension. USPTO.
21 U.S.C. § 355(j). (2024). Abbreviated new drug applications and patent certifications. United States Code.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Boston Scitfc	VARITHENA	polidocanol	SOLUTION;INTRAVENOUS	205098-001	Nov 25, 2013		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

PCT Information
PCT Filed	October 20, 2006	PCT Application Number:	PCT/GB2006/003916
PCT Publication Date:	April 26, 2007	PCT Publication Number:	WO2007/045897

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	E509863	⤷ Start Trial
Cyprus	1112530	⤷ Start Trial
Denmark	1945533	⤷ Start Trial
European Patent Office	1945533	⤷ Start Trial
Spain	2366399	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,480,652

Which drugs does patent 9,480,652 protect, and when does it expire?

Summary for Patent: 9,480,652