Details for Patent: 5,662,271

Summary for Patent: 5,662,271

Title:	Atomizing devices and methods
Abstract:	A metered dose inhaler comprises a piston which is mounted in a cavity within a body, and is urged by a pre-loaded spring into a reduced cross-section pressure chamber. The piston may be loaded by means of an actuating rod having a handle, and may be latched in a loaded position by a latching means. A liquid drug (e.g. in aqueous solution) is contained in a collapsible bag. Metered quantities of the drug are successively presented in the pressure chamber, and then subjected to a sudden and great increase in pressure, to eject the liquid drug through an atomising head, to reduce it to fine atomised spray of small mean particle size--for example less than 30 micrometers. Non-return valves control the flow of liquid through the device. The sudden pressure pulse is caused be releasing the spring loaded piston, upon depressing an actuating button connected by the latching means.
Inventor(s):	Terence Edward Weston, Stephen Terence Dunne
Assignee:	Boehringer Ingelheim International GmbH
Application Number:	US08/459,458
Patent Claim Types: see list of patent claims	Use; Delivery; Device;

United States Drug Patent 5,662,271: Claim Scope, Expiration, and Patent Landscape

US Patent No. 5,662,271 is a device patent covering a mechanically actuated, high-pressure spray dispenser. It is not a drug-composition patent and does not protect a particular active pharmaceutical ingredient. The patent claims a spring-loaded piston system that pressurizes a metered fluid charge, generally to at least 50 bar, and discharges it through an atomizing nozzle or two impinging jets.

The patent issued on September 2, 1997, and its 17-year term expired on September 2, 2014.[1] It therefore presents no current U.S. patent barrier to generic, branded, or device competition. The claims remain relevant as prior art and as a technical description of the architecture associated with high-pressure soft-mist inhalers and related spray dispensers.

What does US Patent 5,662,271 protect?

The patent protects a combination of mechanical and fluid-handling elements rather than a formulation or therapeutic use. The principal combination includes:

1. A chamber containing fluid.
2. A reciprocating piston.
3. A spring or other resilient biasing element.
4. A latch that holds the spring in a loaded condition.
5. An actuator that releases the latch.
6. Pressure elevation to at least 50 bar.
7. An atomizer that converts the discharged fluid into droplets.

Claim 1 is the principal broad combination claim. It requires the piston to move from a loaded position to a discharge position under spring force. That movement raises the fluid pressure from a first pressure to a second pressure of at least 50 bar.

The claim is directed to the operating sequence as well as the component arrangement. A device must be capable of loading the spring, retaining it with a latch, releasing it through an actuator, pressurizing the chamber, and atomizing the resulting discharge.

What is the central inventive concept?

The central concept is a reusable, spring-driven high-pressure pump that creates a spray without relying on a conventional pressurized propellant container. The patent combines:

• Mechanical energy stored in a spring.
• A piston-driven pressure chamber.
• Metered fluid loading from a reservoir.
• One-way valve control.
• Fine-orifice or impinging-jet atomization.

The claims are broad enough to cover non-inhalation spray devices, but claim 38 specifically narrows the technology to a metered dose inhaler containing fluid medicament.

How are the claims organized?

The 49 claims contain several overlapping claim groups. The following structure is the most useful for infringement and freedom-to-operate analysis.

Claim group	Principal subject matter	Key narrowing limitations
Claims 1-21	General spray dispenser	Piston, spring, latch, actuator, 50-bar pressure, atomizer
Claims 22-35	Spray dispenser with reservoir	Reservoir feeds chamber during piston loading
Claims 36-37	Channel-based dispenser	Piston includes a fluid channel; claim 37 adds reservoir filling
Claims 38-45	Metered dose inhaler	Fluid medicament, removable reservoir, non-return valve, impinging jets
Claims 46-49	Functionalized dispenser	"Pressurizing and discharging means" rather than an expressly recited piston

Claims 1, 22, 36, 37 and 46 are independent claims. Claim 38 is an independent claim directed specifically to a metered dose inhaler.

What elements are required by claim 1?

Claim 1 requires all of the following:

• A chamber containing fluid at a first pressure.
• A piston that both pressurizes and discharges the fluid.
• Reciprocation between loaded and discharge positions.
• A resilient biasing element.
• A loaded state for the biasing element.
• A latch holding that loaded state.
• An actuator releasing the latch.
• A pressure increase to at least 50 bar.
• Discharge at the second pressure.
• An atomizing structure.

A device that uses a motor, gas pressure, hydraulic actuator, or manual force instead of a stored resilient biasing element may avoid claim 1, depending on the structure and claim construction. A device that creates a spray at less than 50 bar may also avoid the express pressure limitation, although other claims or related patents could still be relevant.

What do the dependent claims add?

The dependent claims concentrate on fluid loading, reservoir construction, valve architecture, spring type, pressure range, and atomization geometry.

Reservoir and piston claims

Claims 5-13, 22, 25-27 and 34-37 address the relationship between the piston and the fluid reservoir. The relevant configurations include:

• The piston extending from the reservoir.
• The piston being integral with the reservoir.
• A collapsible reservoir.
• A removable reservoir.
• A metered quantity being drawn into the chamber during piston loading.
• A non-return inlet valve located within a piston channel.

The reservoir limitations matter because they move the claims toward cartridge-based or refillable inhaler systems rather than generic pump sprayers.

Valve claims

Claims 3, 4, 14, 27, 28 and 40-42 cover valve arrangements that control fluid movement. The claimed functions include:

• Preventing reverse flow into the reservoir.
• Regulating flow between the pressure chamber and atomizer.
• Preventing air from being drawn backward through the atomizer.
• Maintaining chamber priming and metering accuracy.

Claim 40 requires a non-return valve between the chamber and atomizing means. Claim 41 specifies that the valve prevents air from being sucked into the chamber from the atomizer.

Spring claims

Claims 17-19 and 29-31 identify the resilient biasing element as a spring. The claims expressly cover:

• A spring generally.
• A compression spring.
• A tension spring.

The independent claims do not limit the biasing element to a particular spring type. They use the broader concept of resilient biasing means.

Pressure limitations

Claim 1 establishes a minimum pressure of 50 bar. Claim 15 narrows the range to approximately 300-500 bar. Claim 44 applies the same range to the inhaler of claim 38.

The 300-500 bar range is commercially significant because it distinguishes the claimed system from conventional low-pressure pump sprays and many traditional metered-dose inhalers. In an infringement analysis, actual operating pressure, pressure transient behavior, and the point at which pressure is measured would be material.

Atomizer claims

Claims 20 and 32 cover two outlet apertures that emit separate jets which impinge to form droplets. This is a structural limitation, not merely a functional requirement.

Claims 21 and 33 cover a nozzle orifice with a hydraulic diameter of approximately 1-12 micrometers. A product may fall outside those claims if its orifice geometry produces a hydraulic diameter outside the recited range, but the broader atomizer limitations in the independent claims may remain relevant if the patent were enforceable.

What does claim 38 protect in a metered dose inhaler?

Claim 38 is the most commercially targeted claim. It requires a combination of:

• A chamber for fluid medicament.
• A piston with a channel communicating with the chamber.
• A non-return valve in the channel.
• A spring-driven pressure stroke.
• Pressure of at least 50 bar.
• A removable fluid reservoir.
• The piston extending from the removable reservoir.
• A latch and user actuator.
• An atomizer using two impinging fluid jets.

This claim is substantially narrower than claim 1 because it requires a metered dose inhaler, fluid medicament, a removable reservoir, a piston-channel arrangement, a non-return valve, and impinging jets.

Claims 39-45 add user loading, anti-air-ingress structures, a collapsible reservoir, a 300-500 bar pressure range, and an integral piston-reservoir structure.

How strong was the patent estate?

The patent was technically significant but legally narrow in several respects.

Strength factor	Assessment
Core mechanical architecture	Strong claim coverage during the enforceable term
Drug composition protection	None
Method-of-use protection	None of material commercial significance
Formulation protection	None
Pressure limitation	Creates a meaningful design boundary
Atomizer limitation	Provides additional structural specificity
Reservoir claims	Relevant to refillable and cartridge-based systems
Current enforceability	None after expiration
Orange Book value	None as a device-only patent

The claims use several functional phrases, including "resilient biasing means," "latching means," "actuating means," and "atomising means." These may be interpreted under pre-AIA 35 U.S.C. §112, paragraph 6, now §112(f), where the claim language invokes a means-plus-function format.[2] The corresponding structures disclosed in the specification and their equivalents would therefore be important in any historical infringement analysis.

Claim 46 also uses "pressurizing and discharging means." Although broader in wording than a claim expressly requiring a piston, its scope would depend on the corresponding disclosed structure and equivalents. Claims 47-49 then restore piston-channel and reservoir concepts through dependent limitations.

When did US Patent 5,662,271 lose exclusivity?

The patent expired on September 2, 2014, based on the 17-year term applicable to the pre-1995 filing framework and the issue date.[1] The patent was filed before the transition to the modern 20-year-from-earliest-effective-filing term under the Uruguay Round Agreements Act.

There is no current patent term extension protecting the claimed device. Patent term extension under 35 U.S.C. §156 is directed primarily to regulatory review of approved products, and a device patent of this type does not create an Orange Book drug-patent exclusivity period.[3]

Exclusivity timeline

Event	Date
Earliest priority and filing period	Early 1990s
U.S. patent issued	September 2, 1997
17-year issue-based term	September 2, 2014
Current status	Expired
Current blocking effect	None

What is the Orange Book status of US Patent 5,662,271?

US 5,662,271 is not an Orange Book-listed drug patent. The Orange Book lists patents submitted for approved drug products, including patents directed to active ingredients, formulations, compositions, and methods of use.[3] A standalone spray-device patent does not automatically qualify for listing against an approved drug product.

The patent therefore does not create:

• A 30-month stay against an ANDA.
• A Paragraph IV certification issue by itself.
• Regulatory exclusivity for a drug product.
• A bar to generic substitution.
• A patent-based delay in FDA approval of a drug application.

A drug sponsor could have separately listed formulation, composition, or method-of-use patents for a product delivered through a similar device. Those rights would need to be analyzed independently.

Are there Paragraph IV challenges or biosimilar risks?

There is no direct Paragraph IV risk tied to US 5,662,271 because the patent is expired and was not a drug patent. A generic applicant would not need to challenge this patent to obtain approval of an unrelated drug product.

Biosimilar risk is also not applicable. Biosimilars are regulated under the Public Health Service Act and involve biologic reference products. US 5,662,271 claims a mechanical delivery device and does not cover a biologic, therapeutic protein, or biologic manufacturing process.[4]

For inhaled drugs, the more relevant current barriers are usually:

• Drug formulation patents.
• Device-device compatibility patents.
• Dose-metering patents.
• Cartridge or reservoir patents.
• Manufacturing and assembly patents.
• FDA requirements for equivalent performance and product-device interaction.

What patent litigation affects US 5,662,271?

The patent’s expiration eliminates its prospective enforcement value. Historical disputes involving soft-mist inhaler technology could have involved this patent or related family members, but the patent cannot support a current injunction against a competing U.S. product.

Any historical damages analysis would be subject to statutory limits, including the six-year limitation in 35 U.S.C. §286.[5] A current product review should therefore focus on unexpired continuation, divisional, improvement, or separately filed device patents rather than on US 5,662,271 itself.

No settlement agreement, license, or active U.S. litigation can extend the expired patent’s exclusionary term.

How does this patent compare with drug and formulation patents?

Patent type	Protects	Relevance of US 5,662,271
Active-ingredient patent	Chemical entity	Not covered
Formulation patent	Composition and excipients	Not covered
Method-of-use patent	Treatment indication or dosing	Not covered
Device patent	Inhaler or dispenser structure	Directly covered
Manufacturing patent	Assembly or production process	Not directly covered
Biologic patent	Protein, antibody, or cell product	Not covered

The patent’s commercial value was linked to the delivery platform, not to a particular medicine. A company could potentially use the expired architecture with a new formulation, subject to other live patents and regulatory requirements.

What generic launch risks remain?

US 5,662,271 creates no current generic launch risk because it is expired. Remaining risk may arise from other rights in the same product ecosystem:

• Live patents covering a specific inhaler design.
• Patents covering a refill cartridge or collapsible reservoir.
• Nozzle manufacturing tolerances.
• Dose-metering systems.
• Formulation stability.
• Device-drug interaction.
• Human-factor or priming mechanisms.
• Manufacturing processes for micro-orifice atomizers.

The expired patent can still limit the availability of patent protection for broad versions of the same mechanical concept. A later patent must contain a novel and non-obvious improvement rather than simply restating the disclosed spring-piston high-pressure dispenser.

What is the competitive landscape?

The technology described by the patent is associated with propellant-free, high-pressure spray delivery. Relevant commercial categories include:

• Soft-mist inhalers.
• Propellant-free metered dose inhalers.
• Refillable liquid inhalers.
• Nasal spray and pulmonary delivery devices.
• High-pressure micro-nozzle dispensers.
• Unit-dose and cartridge-based fluid atomizers.

The principal competitive distinction is between device platforms and drug products. A company may own a strong device patent estate while obtaining separate protection for the delivered medicine. Conversely, an expired platform patent does not mean that a commercial inhaler is free of all patent constraints.

Key Takeaways

• US 5,662,271 is a device patent, not a drug, formulation, or method-of-use patent.
• Its central claim requires a spring-loaded piston, latch, actuator, pressure chamber, pressure increase to at least 50 bar, and atomizer.
• Claim 38 specifically targets a metered dose inhaler with a removable reservoir, non-return valve, piston channel, and impinging-jet atomizer.
• Claims 15 and 44 identify an approximately 300-500 bar operating range.
• The patent expired on September 2, 2014.
• It is not an Orange Book drug patent and creates no current Paragraph IV or biosimilar barrier.
• Current freedom-to-operate analysis must examine later device, formulation, cartridge, nozzle, manufacturing, and drug-specific patents.
• Historical claim construction would likely give substantial importance to the specification because several limitations use means-plus-function language.

FAQs

Does US 5,662,271 cover Respimat drug formulations?

No. The patent claims a dispensing device and inhaler architecture. It does not claim a particular active ingredient, formulation, or therapeutic indication.

Can a company obtain an FDA-approved inhaler using the expired patent architecture?

Potentially, yes. The expired patent does not prevent use of its disclosed technology. FDA approval would still depend on the drug, device, combination-product pathway, performance data, and applicable current patents.

Does the 50-bar limitation apply to every claim?

It applies to the independent claims that expressly recite the pressure increase, including claims 1, 22, 36, 37 and 46. Dependent claims inherit the limitations of the claims from which they depend.

Are the 1-12 micrometer nozzle claims still enforceable?

No. Claims 21 and 33 expired with the patent on September 2, 2014. The numerical limitation remains relevant as prior art and as a technical description.

Can an expired patent still affect patentability of a new inhaler?

Yes. The patent can be cited as prior art against later patent applications. A later applicant would need to establish novelty and non-obviousness through a distinct structure, operating parameter, manufacturing process, or technical result.

References

1. United States Patent and Trademark Office. (1997). U.S. Patent No. 5,662,271, Device for dispensing fluid as a spray of droplets.
2. 35 U.S.C. §112(f) (2018).
3. U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.
4. Public Health Service Act, 42 U.S.C. §262.
5. 35 U.S.C. §286.

Drugs Protected by US Patent 5,662,271

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

Foreign Priority and PCT Information for Patent: 5,662,271

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
United Kingdom	9006340	Mar 21, 1990
United Kingdom	9023767	Nov 01, 1990

International Family Members for US Patent 5,662,271

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	160947
Austria	189413
Australia	650870
Australia	7548491
Brazil	9106249
Canada	2078683
Canada	2206753