United States Patent 9,393,210: Levodopa Inhalation Capsule Claims, Patent Scope, and Competitive Landscape

US Patent 9,393,210 protects a specific levodopa dry-powder capsule configuration for use in an inhalation device. Its strongest protection is the combination of four elements: a capsule shell containing hydroxypropyl methylcellulose and titanium dioxide, a levodopa dry powder, a fine-particle fraction of at least 50% of the nominal dose, and, in narrower claims, defined moisture, dose, capsule size, excipient, and density parameters.[1]

The patent does not broadly cover every levodopa inhalation product. A potentially infringing product would generally need to satisfy the independent claim and any additional limitations of the asserted dependent claim. The commercial significance is greatest for products using a low-density, high-dispersibility levodopa powder packaged in a size 00 hypromellose capsule.

What does US Patent 9,393,210 claim?

Claim 1 is the controlling independent claim. It requires all of the following:

Claim element	Required limitation
Dosage form	Capsule
Intended use	Use in an inhalation device
Capsule fill	Dry powder comprising levodopa
Capsule shell	Hydroxypropyl methylcellulose and titanium dioxide
Aerosol performance	Fine-particle fraction of at least 50% of the nominal powder dose

The claim is a product claim directed to the capsule and its contents. It is not principally a claim to the inhaler, the manufacturing process, or a treatment method. The phrase “for use in an inhalation device” provides an intended-use limitation that may have limited force if the physical capsule is otherwise structurally suitable for inhalation.

The claim’s practical center is the combination of capsule-shell composition and powder-performance characteristics. A levodopa powder that achieves a fine-particle fraction of 50% or more but is packaged in a shell lacking hydroxypropyl methylcellulose or titanium dioxide would present a claim 1 non-infringement position. The same would apply to a qualifying shell filled with a levodopa powder that does not meet the claimed fine-particle fraction.

How broad is the independent claim?

Claim 1 is moderately narrow because it requires a particular shell material, an inhalable levodopa powder, and a quantitative aerodynamic-performance threshold.

It is broad in several respects:

It does not require sodium chloride.
It does not require DPPC.
It does not specify a levodopa concentration.
It does not require a particular inhaler.
It does not require a particular powder mass.
It does not require a particular capsule size.
It does not require a particular working density.
It does not impose the narrower water-content ranges in claims 2 and 3.

The claim also does not expressly require that levodopa be the only active pharmaceutical ingredient. A product containing levodopa together with another active compound could potentially fall within the claim if the other limitations are met.

“Comprising” is an open-ended transition. Under ordinary patent-claim interpretation, a capsule containing the listed components plus additional excipients can still satisfy the claim. The addition of lactose, a phospholipid, a salt, a buffer, or another inactive ingredient would not by itself avoid claim 1.

What formulations are protected by the dependent claims?

The dependent claims create a layered formulation and presentation claim set.

Claims	Added limitation	Commercial effect
2	Water content of about 2% to about 8% by weight	Captures moderately humidified or moisture-conditioned powder
3	Water content of about 5% to about 6% by weight	Narrower moisture range
4	Size 00 capsule	Targets a defined capsule format
5	15 mg to 50 mg levodopa	Defines a broad levodopa payload
6	25 mg to 35 mg levodopa	Narrows the payload to a commercially practical range
7	Salt present	Covers salt-containing formulations
8	Sodium chloride	Narrows claim 7 to sodium chloride
9	Phospholipid present	Covers lipid-containing powder
10	DPPC	Narrows claim 9 to dipalmitoylphosphatidylcholine
11	DPPC and sodium chloride	Combination excipient claim
12	Fine-particle fraction about 50% to about 70%	Narrows the aerosol-performance range
13	30 mg to 50 mg total dry powder	Defines capsule fill mass
14	Working density 0.02 g/cm³ to 0.1 g/cm³	Captures low-density powder
15	Working density 0.02 g/cm³ to 0.05 g/cm³	Narrower low-density range

Claims 5, 6, 13, 14, and 15 are particularly relevant to product-specific freedom-to-operate work because they combine measurable physical parameters with a defined capsule presentation. A competing product may avoid one dependent claim while still presenting a claim 1 risk.

Claim 15 contains the wording “claim of claim 1,” which appears to be a drafting typographical error. Its intended dependency is likely claim 1. The legal effect depends on the issued patent text, prosecution history, and any certificate of correction. The typo should not be treated as automatically invalidating the claim.

How should fine-particle fraction be interpreted?

Fine-particle fraction is the most technically important limitation in claim 1. It generally refers to the proportion of an inhaled powder dose reaching a defined aerodynamic particle-size range under a specified testing protocol. The percentage alone is not sufficient to establish infringement.

A comparison would normally examine:

The nominal powder dose loaded into the capsule.
The emitted dose from the inhaler.
The aerodynamic particle-size distribution.
The cut-off diameter used to define the fine-particle fraction.
The impactor or analyzer used.
Flow rate and pressure drop.
Inhaler resistance.
Number of tested capsules and statistical treatment.
Whether the percentage is calculated against nominal dose, emitted dose, or recovered dose.

The claim expressly uses “nominal powder dose,” while claim 12 refers to “the total amount of powder in the capsule.” Those phrases may create different calculation issues. A product developer should not rely on an apparent numerical difference without evaluating the testing method and claim construction.

A design that produces a fine-particle fraction below 50% would address the express numerical limitation, but it could compromise commercial performance and may implicate other patents covering aerosolization, particle engineering, or inhaler operation.

How do the water-content and density limitations affect scope?

Claims 2 and 3 protect defined powder moisture levels. Water content can affect powder cohesion, flow, aerosolization, chemical stability, and capsule compatibility. Claim 3 is narrower than claim 2 because the 5% to 6% range falls within the broader 2% to 8% range.

Claims 14 and 15 protect working density. The claimed ranges are very low:

Claim 14: 0.02 g/cm³ to 0.1 g/cm³.
Claim 15: 0.02 g/cm³ to 0.05 g/cm³.

Working density is not necessarily the same as true particle density or tapped density. It may depend on the powder bed, filling procedure, compaction state, and measurement protocol. The specification and prosecution record would be important in determining the proper test method.

The density claims can create infringement risk even where particle chemistry differs. A competitor using a different particle-engineering process could still fall within the claims if the final powder has the claimed density and the product also satisfies the broader capsule and levodopa limitations.

What excipients are protected by the patent?

The patent’s excipient protection is cumulative rather than exhaustive.

Claim 7 covers a powder containing a salt. Claim 8 specifically identifies sodium chloride. Claim 9 covers a phospholipid. Claim 10 identifies DPPC. Claim 11 requires both DPPC and sodium chloride.

This structure creates a hierarchy:

A formulation with sodium chloride and no DPPC may fall within claim 8.
A formulation with DPPC and no sodium chloride may fall within claim 10.
A formulation with both may fall within claim 11.
A formulation containing another salt or phospholipid may fall within claims 7 or 9, depending on the claim language and construction.

Claims 7 through 11 are dependent claims, so they inherit every limitation of claim 1. The presence of sodium chloride or DPPC alone does not create infringement if the capsule shell or fine-particle-fraction requirement is absent.

What is the likely commercial relevance to Inbrija?

The claim set is technically aligned with the commercial architecture of inhaled levodopa products such as Inbrija, which uses levodopa inhalation powder delivered through a device and capsule-based dosing. The overlap should not be treated as proof that every commercial product practices every claim. Product labeling, regulatory filings, capsule specifications, and analytical data determine the factual comparison.

A product-risk review should compare:

Product attribute	Patent issue
Hypromellose capsule shell	Potential claim 1 relevance
Titanium dioxide in shell	Potential claim 1 relevance
Levodopa powder	Required by claim 1
FPF of at least 50%	Required by claim 1
00 capsule	Claim 4
25 mg to 35 mg levodopa	Claim 6
30 mg to 50 mg total powder	Claim 13
DPPC and sodium chloride	Claim 11
Working density below 0.05 g/cm³	Claim 15
5% to 6% water	Claim 3

A generic or follow-on product that uses a different shell polymer could reduce risk under claim 1. That strategy would not eliminate risk from separate patents covering the inhaled powder, inhaler device, particle morphology, manufacturing process, or therapeutic use.

What patent landscape surrounds levodopa inhalation products?

The relevant patent landscape normally divides into six families of rights:

Capsule and container patents

These cover capsule materials, shell opacity, moisture content, capsule dimensions, sealing, storage, and compatibility with inhalation devices. US 9,393,210 is principally relevant to this category.

Powder-composition patents

These may cover levodopa particle size, engineered particles, excipient combinations, phospholipids, salts, carrier-free powders, and moisture-controlled formulations.

Inhaler-device patents

These may cover piercing mechanisms, airflow paths, capsule rotation, powder deaggregation, dose recovery, and device resistance. A product can avoid a formulation claim yet infringe a device claim.

Manufacturing patents

Relevant process claims may cover spray drying, particle formation, blending, filling, conditioning, and packaging. These rights can create manufacturing barriers even when the final product is designed around a formulation patent.

Method-of-use patents

These may cover treating “off” episodes in Parkinson’s disease, dosing schedules, as-needed administration, and combinations with oral levodopa or other Parkinson’s therapies.

Regulatory and labeling patents

FDA-listed method-of-use patents can affect abbreviated new drug application certification strategy. A product may need a section viii labeling carve-out or may face a Paragraph IV dispute if it seeks approval for a patented indication.[2]

When does US Patent 9,393,210 lose exclusivity?

The patent’s precise expiration date cannot be determined from the claims alone. It depends on the earliest effective nonprovisional or international filing date, patent-term adjustment, patent-term extension, terminal disclaimer, and any reissued or corrected patent record.[3]

The patent number establishes that the patent issued, but it does not establish the operative expiration date. The term must be verified against the USPTO patent record and any Orange Book listing. Patent term adjustment can extend the ordinary 20-year term, while terminal disclaimers can limit the term to that of another patent.

FDA regulatory exclusivity is separate from patent exclusivity. New-drug exclusivity, pediatric exclusivity, and orphan-drug exclusivity do not necessarily have the same duration as a patent and do not replace patent analysis.[2]

What is the Orange Book status and Paragraph IV risk?

The claims supplied do not establish whether US 9,393,210 is listed in the FDA Orange Book, whether it is listed against a particular drug product, or whether any Paragraph IV certification has been filed.[2]

If listed, the patent could affect an ANDA applicant whose proposed product contains levodopa in a capsule configuration that meets the claim limitations. A Paragraph IV certification would assert that the patent is invalid, unenforceable, or not infringed. A listed patent can trigger patent litigation under the Hatch-Waxman Act and a potential 30-month stay, subject to statutory conditions and FDA timing rules.[4]

The most plausible design-around positions would target:

A capsule shell without both hydroxypropyl methylcellulose and titanium dioxide.
A fine-particle fraction below the claimed threshold, if commercially acceptable.
A non-00 capsule.
A different moisture range.
A different excipient system.
A powder density outside the claimed ranges.
A delivery format that does not use a capsule in an inhalation device.

Each approach requires a separate review of other patents in the estate.

Which companies are likely to challenge or license the estate?

A specific challenger, licensee, or settlement cannot be identified from the claim text. In the commercial levodopa inhalation field, the relevant parties include the branded-product sponsor, generic pharmaceutical companies, inhalation-device manufacturers, contract development and manufacturing organizations, and companies developing Parkinson’s disease delivery systems.

Licensing and settlement terms are often not visible in patent claims. They may appear in district-court dockets, SEC filings, Federal Trade Commission materials, or ANDA litigation records. The existence of a patent does not establish that the owner has granted a license or settled a challenge.

How strong is the patent estate for a competing levodopa inhalation product?

US 9,393,210 has meaningful but configuration-dependent strength.

Its strongest features are:

A quantitative aerosol-performance limitation.
A defined capsule-shell composition.
Multiple dependent claims directed to commercially realistic fill weights and excipients.
Low-density powder claims that may capture engineered inhalation powders.
Narrow claims covering DPPC and sodium chloride together.

Its vulnerabilities may include:

Dependence on test methodology for fine-particle fraction.
Potential design-around through capsule-shell composition.
Potential design-around through powder density, water content, or excipient selection.
Possible enablement, written-description, or indefiniteness disputes over technical measurements, depending on the specification and prosecution history.
The limited scope of a capsule claim against non-capsule delivery systems.

Patent strength cannot be rated solely from the issued claims. Validity depends on the prior-art record, prosecution amendments, claim construction, written description, enablement, and post-grant proceedings.

What generic launch scenarios exist?

A generic applicant could pursue several launch strategies:

Full product challenge. The applicant certifies Paragraph IV against listed patents and seeks approval for a product matching the reference product’s dosage form and use.
Formulation design-around. The applicant changes capsule-shell composition, excipients, powder density, or moisture content.
Device redesign. The applicant uses a different inhalation mechanism or a non-capsule delivery system.
Label carve-out. The applicant removes a patented method of use if FDA labeling and clinical positioning permit a section viii strategy.
Post-expiration launch. The applicant avoids early litigation by targeting approval after the relevant patent and regulatory exclusivities expire.

The first strategy carries the highest litigation exposure because a commercially equivalent product may satisfy multiple claims in the same patent family and related patents.

Key Takeaways

US 9,393,210 is directed to a levodopa dry-powder capsule for inhalation.
Claim 1 requires a hypromellose-and-titanium-dioxide shell, levodopa powder, and a fine-particle fraction of at least 50% of nominal dose.
Dependent claims cover moisture, capsule size, levodopa payload, total powder mass, DPPC, sodium chloride, and low working density.
The most commercially relevant combinations are size 00 capsules, 25 mg to 35 mg levodopa, 30 mg to 50 mg total powder, DPPC plus sodium chloride, and density below 0.05 g/cm³.
Fine-particle-fraction testing and working-density methodology are central infringement issues.
The claims do not by themselves establish Orange Book listing, patent expiration, Paragraph IV activity, litigation, licensing, or settlement status.
A design-around based on capsule shell, excipient, density, or delivery format may reduce risk under this patent but will not resolve the broader levodopa inhalation patent estate.
The precise expiration date requires the official patent-term and regulatory records, not the claim text alone.

FAQs about US Patent 9,393,210

Does US 9,393,210 cover levodopa tablets?

No. The supplied claims require a capsule filled with a levodopa dry powder for use in an inhalation device. Oral tablets are outside the literal scope of these claims.

Does the patent require DPPC?

No. DPPC appears only in dependent claims 9 through 11. Claim 1 does not require DPPC or any phospholipid.

Can a capsule avoid the patent by using gelatin instead of hypromellose?

A gelatin capsule would present a position against literal infringement of claim 1 because claim 1 requires a shell comprising hydroxypropyl methylcellulose and titanium dioxide. The full patent record would still be relevant to any doctrine-of-equivalents analysis.

Does a fine-particle fraction of exactly 50% fall within claim 1?

Yes, claim 1 expressly requires “at least 50%.” The measurement protocol and calculation denominator remain material.

Is a size 00 capsule required for all claims?

No. Size 00 is required only by claims 4 through 6. Claim 1 is not limited to a particular capsule size.

Does patent expiration eliminate FDA exclusivity?

No. Patent expiration and FDA regulatory exclusivity are separate legal mechanisms. A product may remain subject to regulatory exclusivity after a patent expires, or may face no regulatory exclusivity while a patent remains enforceable.

References

U.S. Patent No. 9,393,210, claims 1–15. United States Patent and Trademark Office.
U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations (Orange Book).
United States Patent and Trademark Office. (n.d.). Patent term adjustment.
Drug Price Competition and Patent Term Restoration Act, 21 U.S.C. § 355(j); 35 U.S.C. §§ 271(e), 282.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Merz	INBRIJA	levodopa	POWDER;INHALATION	209184-001	Dec 21, 2018		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

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2013342246	⤷ Start Trial
Australia	2013342247	⤷ Start Trial
Australia	2013342248	⤷ Start Trial
Australia	2017279626	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,393,210

Which drugs does patent 9,393,210 protect, and when does it expire?

Summary for Patent: 9,393,210