US Patent 8,431,154: Roflumilast Formulation Claims, Patent Scope and Generic-Entry Risk

US Patent No. 8,431,154 protects immediate-release oral dosage forms containing roflumilast or specified roflumilast-related compounds made by aqueous polyvinylpyrrolidone, or PVP, granulation. Its commercial center is the 0.125 mg, 0.25 mg and 0.5 mg roflumilast tablet formulation containing lactose, corn starch, high-molecular-weight PVP and magnesium stearate.

The patent is a formulation and manufacturing patent, not a basic compound patent. Its strongest commercial coverage is directed to tablets made through wet granulation, especially formulations using a roflumilast suspension or solid solution in PVP. It does not broadly cover every oral roflumilast product or every immediate-release tablet.

What drug does US Patent 8,431,154 protect?

The principal active ingredient is roflumilast, chemically identified as N-(3,5-dichloropyrid-4-yl)-3-cyclopropylmethoxy-4-difluoromethoxybenzamide. Roflumilast is a selective phosphodiesterase-4, or PDE4, inhibitor used for reduction of the risk of COPD exacerbations.

The claims also encompass:

A salt of roflumilast;
The N-oxide of roflumilast's pyridine ring;
Salts of the N-oxide;
Certain dosage forms containing the claimed PDE4 inhibitor rather than roflumilast alone.

The commercial product most closely aligned with the patent is Daliresp, an immediate-release oral tablet approved by FDA under NDA 022522. FDA approved Daliresp in 2011 for reducing the risk of COPD exacerbations in patients with severe COPD associated with chronic bronchitis and a history of exacerbations.[1]

Core chemical limitation

The formula in the independent claims fixes the three substituents as follows:

Position	Claimed substituent
R1	Difluoromethoxy
R2	Cyclopropylmethoxy
R3	3,5-dichloropyrid-4-yl

This substantially narrows the patent compared with a generic PDE4 inhibitor claim. A product containing another PDE4 inhibitor would not fall within the literal active-ingredient limitation.

What are the independent claims in US 8,431,154?

The patent has three principal independent claim categories.

Claim	Covered product or process configuration	Commercial significance
1	Active ingredient and excipients are mixed, then granulated with aqueous PVP	Broadest wet-granulation formulation claim
9	Excipients are mixed first, then granulated with a suspension of the active ingredient in aqueous PVP	Directly targets active suspension spraying or incorporation
11	A solid solution of the active ingredient in PVP is prepared before blending and granulation	Targets amorphous or molecularly dispersed active-ingredient preparation

Each independent claim requires that the final dosage form:

Be for oral administration;
Contain the specified PDE4 compound or related N-oxide/salt;
Be in tablet or pellet form; and
Provide immediate release of the active ingredient.

The claims are framed as dosage-form claims "produced by the process comprising" specified manufacturing steps. This creates a product-by-process structure. Under US patent law, a product-by-process claim generally turns on the identity of the claimed product, while the recited process limitations remain relevant to claim construction and infringement analysis. A competitor cannot assume that a different manufacturing label eliminates risk if its final product is materially the same as the claimed product. The Federal Circuit's decisions in Abbott Laboratories v. Sandoz and Amgen v. F. Hoffman-La Roche are relevant to product-by-process analysis.[2,3]

How broad is the scope of claim 1?

Claim 1 covers an immediate-release tablet or pellet produced by:

Mixing roflumilast, a permitted salt, or a permitted N-oxide with one or more excipients;
Granulating that mixture using an aqueous PVP solution.

The claim does not require a particular filler, lubricant, PVP grade, PVP concentration, tablet strength or granulator type. Those limitations appear in dependent claims.

Claim 1 therefore reaches a relatively broad class of roflumilast wet-granulated immediate-release products. It may cover a product even if the excipient system differs from the commercial example, provided the claimed process and dosage-form features are met.

The principal limitations are:

The active ingredient must be roflumilast or the specified related compound;
PVP must be used in an aqueous granulation step;
The dosage form must be a tablet or pellet;
Release must be immediate.

A direct-compression tablet that never undergoes aqueous PVP granulation is outside the literal process description of claim 1. A dry-granulated product may also avoid the literal claim if no aqueous PVP granulation occurs.

What formulations are protected by claims 7, 8, 10 and 27 through 38?

The dependent claims narrow the formulation to specific excipient systems and strengths.

Lactose and corn starch formulation

Claims 7 and 10 cover a formulation using:

Roflumilast or a roflumilast/corn-starch trituration;
Corn starch;
Lactose monohydrate;
Aqueous PVP;
Drying;
A release agent;
Compression into a tablet.

Claims 27 through 29 and 33 through 38 identify a specific composition:

Component	Amount per tablet
Roflumilast	0.125 mg, 0.250 mg or 0.500 mg
Lactose monohydrate	49.660 mg
Corn starch	13.390 mg
PVP, molecular weight 1,000,000-1,500,000	1.300 mg
Vegetable magnesium stearate	0.650 mg
Approximate total weight	65.125 mg, excluding strength-related variation

The PVP concentration in this example is approximately 2.0% by weight. That falls within the narrower 1%-5% range of claim 18 and the 2%-3% range of claim 19.

Microcrystalline cellulose and sodium carboxymethylstarch formulation

Claim 8 covers a separate excipient system using:

Corn starch;
Microcrystalline cellulose;
Sodium carboxymethylstarch;
A roflumilast/corn-starch trituration or roflumilast;
Aqueous PVP;
Drying and compression.

This claim is narrower than claim 1 but may be important for generic formulations that use standard tablet disintegrants and fillers.

Solid-solution formulation

Claims 11, 30 and 31 cover an active-ingredient preparation in PVP before the main granulation process. Claim 31 narrows the preparation to an amorphous molecular dispersion.

This feature is technically significant because roflumilast has low aqueous solubility. A molecular dispersion in PVP can improve content uniformity and dissolution performance at low drug loads. The claim does not merely require PVP as a conventional binder. It requires PVP to function as a carrier for a solid solution or amorphous molecular dispersion.

A generic manufacturer using crystalline roflumilast blended directly with lactose and starch may avoid claims 11, 30 and 31 while remaining exposed to claims 1 or 9 if it uses aqueous PVP granulation.

Which dependent claims create the most commercially relevant coverage?

The claims can be ranked by likely commercial importance.

Claim group	Limitation	Risk relevance
1	General aqueous PVP granulation	Highest breadth
9	Active suspension incorporated into aqueous PVP granulation	High for fluid-bed spray processes
11	PVP solid solution before granulation	High if amorphous dispersion is used
14	Specific PVP molecular-weight ranges	Important for grade-specific formulations
17	0.01 mg to 5 mg roflumilast	Covers marketed strengths
18-19	PVP at 1%-5% or 2%-3%	Relevant to commercial formulation matching
22-26	Filler, lubricant and excipient categories	Moderate narrowing
27-29	Specific 0.125 mg, 0.25 mg and 0.5 mg compositions under claim 9	Strong product-specific coverage
33-35	Same strengths under claim 1	Strong product-specific coverage
36-38	Same strengths under claim 11	Strong coverage where solid-solution preparation is used

Claims 27 through 38 are particularly relevant to Daliresp-style tablets because they recite the marketed strength range and the principal qualitative composition.

How does the patent cover manufacturing methods?

The patent covers three manufacturing architectures.

Conventional wet granulation

Under claim 1, roflumilast and excipients are mixed before aqueous PVP is added. The mixture is then granulated. The process may include drying, blending with a lubricant or release agent and compression.

Active suspension granulation

Under claim 9, the excipient bed is prepared first. Roflumilast is present in a suspension in an aqueous PVP solution, which is used to granulate the excipient mixture.

This distinction matters. A manufacturer could use the same final excipients but vary the point at which roflumilast is introduced. That variation may determine whether claim 1, claim 9 or both are implicated.

Solid-solution route

Under claim 11, the active ingredient is first converted into a solid solution in PVP. The preparation is then mixed with excipients and granulated with aqueous PVP.

Claim 31 adds the amorphous molecular-dispersion limitation. Analytical testing, including powder X-ray diffraction, differential scanning calorimetry, Raman spectroscopy or solid-state NMR, could become relevant in a formulation dispute.

What is the Orange Book status of US 8,431,154?

US 8,431,154 is associated with the roflumilast tablet product and has been treated as a formulation patent relevant to Daliresp. The FDA Orange Book is the controlling public source for current listed-patent and use-code information.[4]

The patent should be analyzed separately from:

FDA chemical exclusivity;
FDA three-year clinical-investigation exclusivity;
The basic roflumilast compound patent;
Patents covering non-oral or topical roflumilast products;
Regulatory exclusivity for other roflumilast indications.

An Orange Book listing does not establish that every claim is valid or infringed. It affects ANDA certification and potential Hatch-Waxman litigation.

Exclusivity timeline

Event	Date or status
Roflumilast compound and PDE4 development	Prior-generation patent estate
Daliresp FDA approval	2011
US Patent 8,431,154 grant	April 30, 2013
Listed formulation-patent term endpoint reported in public patent records	August 16, 2028, subject to applicable term adjustment or disclaimer
Generic pathway	ANDA with Paragraph III or Paragraph IV certification, depending on current Orange Book status

The patent's effective commercial blocking period depends on its actual adjusted expiration date, Orange Book listing, any terminal disclaimer, and the status of FDA exclusivities. The grant date does not determine the expiration date.

When does US 8,431,154 lose exclusivity?

Public patent records identify August 16, 2028 as the ordinary term endpoint associated with the patent family, subject to any patent-term adjustment and statutory limitations.[5] The relevant term calculation must be confirmed against the USPTO patent record and the Orange Book listing.

The patent is not a biologic patent and does not create biosimilar exclusivity. Roflumilast is a small molecule. The principal regulatory competition is through ANDAs, not 351(k) biosimilar applications.

A generic applicant could seek approval before patent expiry by:

Filing a Paragraph III certification and delaying launch until expiry;
Filing a Paragraph IV certification alleging invalidity, unenforceability or noninfringement;
Designing around aqueous PVP granulation;
Challenging the patent through inter partes review or another post-grant mechanism, where statutory requirements are met.

What Paragraph IV challenges and litigation affect the patent?

The supplied claim set does not identify a specific ANDA filer, litigation docket or settlement agreement. A definitive litigation conclusion cannot be drawn from the claims alone.

For diligence purposes, the relevant records are:

FDA Orange Book patent and exclusivity data;
FDA Paragraph IV notice information;
PACER and district-court docket records;
PTAB proceedings;
Settlement agreements submitted under the Medicare Modernization Act;
SEC filings by the NDA holder and generic applicants.

The legal issues most likely to arise are:

Whether a generic product is made by aqueous PVP granulation;
Whether the PVP is used as a binder, carrier or solid-solution medium;
Whether the product provides immediate release;
Whether the active ingredient is roflumilast in the claimed chemical form;
Whether the process limitations define a materially different product;
Whether the asserted claims are anticipated or obvious over earlier roflumilast formulations.

How strong is the patent estate for roflumilast?

US 8,431,154 has moderate formulation-patent strength and limited molecule-level breadth.

Strengths

It targets the marketed oral dosage form and commercial strengths.
Claims 27 through 38 provide detailed composition coverage.
The claims cover both conventional active-plus-excipient granulation and active suspension granulation.
The solid-solution claims address a technically meaningful formulation strategy.
The claimed excipients are common in pharmaceutical manufacturing, which may make the patent commercially relevant to standard generic processes.

Weaknesses

The patent does not cover roflumilast as a chemical compound in all dosage forms.
It requires immediate-release oral tablets or pellets.
It requires aqueous PVP granulation in the independent claims.
Many dependent claims are limited to specific excipients, PVP concentrations, molecular weights or strengths.
Common wet-granulation technology may provide prior-art material for validity challenges.
A formulation designed around dry granulation, direct compression, a non-PVP binder or a different active-loading method may avoid literal infringement.

The estate is strongest against a generic applicant that copies the Daliresp composition and manufacturing sequence. It is weaker against a product that uses direct compression, dry granulation, a different binder system or a different solid-state form.

What generic launch scenarios exist?

Scenario	Technical strategy	Patent risk
Copy formulation	Lactose, corn starch, high-MW PVP, magnesium stearate; aqueous granulation	High
Composition variation	Different filler or lubricant, same aqueous PVP process	Moderate to high under claim 1 or 9
Dry granulation	No aqueous PVP granulation	Lower literal risk
Direct compression	No granulation step	Lower risk, subject to product equivalence issues
Alternative binder	Hydroxypropyl cellulose, hypromellose or another binder	Lower risk if no PVP granulation
Solid-state redesign	Crystalline active without PVP molecular dispersion	Avoids claims 11 and 31, but not necessarily claim 1
Pellet product	Immediate-release roflumilast pellets	Potentially covered because claims expressly include pellets
Topical product	Roflumilast cream or foam	Outside the oral tablet/pellet claims

A generic applicant must assess the actual manufacturing process, not only the qualitative ingredient list. Two products with nearly identical tablets may have different infringement profiles if the active ingredient is introduced by different granulation routes.

How does US 8,431,154 compare with other roflumilast patents?

Patent category	Subject matter	Relevance to Daliresp
Basic compound patents	Roflumilast and related PDE4 chemistry	Historically important; generally earlier-expiring
Formulation patent 8,431,154	Immediate-release oral tablets or pellets using aqueous PVP granulation	Directly relevant to Daliresp tablets
Method-of-use patents	COPD, exacerbation reduction and respiratory indications	May affect approved-use labeling
Topical formulation patents	Creams, foams and dermatological delivery	Relevant to Zoryve, not Daliresp tablets
Manufacturing patents	Solid-state preparation, granulation and process controls	May create additional process-specific risk
Regulatory exclusivity	FDA approval and clinical data protection	Separate from patent rights

Roflumilast topical products have a different commercial and patent landscape from oral COPD tablets. A topical roflumilast product does not ordinarily implicate the dosage-form limitations of US 8,431,154.

What geographic coverage does the patent provide?

US 8,431,154 provides rights only in the United States. The corresponding international family may include European and other national filings, but each jurisdiction has separate claims, prosecution history, term rules and validity risks.

A global freedom-to-operate review should distinguish:

United States formulation claims;
European Patent Office family members;
German, French, Italian, Spanish and UK national rights;
Canadian, Japanese and Australian counterparts;
Any divisional, continuation or national-phase applications;
Post-grant amendments and opposition outcomes.

A US design-around does not establish freedom to operate in Europe. Conversely, a European family member may have narrower claims or may have expired even if the US patent remains relevant.

What manufacturing and IP barriers remain?

The main barrier is not the availability of roflumilast API. It is the combination of:

Very low active dose;
Content-uniformity requirements;
Solubility and dissolution control;
PVP selection;
Wet-granulation process parameters;
Solid-state characterization;
Immediate-release performance;
Commercial-scale reproducibility.

The 0.125 mg and 0.25 mg strengths are particularly sensitive to blend uniformity and segregation. A generic manufacturer may avoid a literal claim while still needing comparative dissolution, stability and bioequivalence data acceptable to FDA.

The most defensible design-around is generally a formulation and process that avoids aqueous PVP granulation entirely. That approach may require a different binder, dry processing or a direct-compression strategy, with corresponding development risk.

What is the commercial exposure?

Daliresp's commercial exposure is concentrated in the oral COPD market. The patent is most valuable during the period in which the branded product has meaningful US sales and before ANDA competition reduces price.

The commercial risk from a Paragraph IV generic would include:

Loss of tablet volume;
Price erosion after first generic entry;
Possible 180-day first-filer exclusivity;
Litigation costs;
Settlement-related launch timing;
Substitution across the 0.125 mg, 0.25 mg and 0.5 mg strengths.

The patent does not protect all roflumilast revenue. It does not directly cover topical products, non-oral dosage forms, or products using a materially different manufacturing platform.

Key Takeaways

US 8,431,154 is a roflumilast formulation and manufacturing patent.
The independent claims require an immediate-release oral tablet or pellet made using aqueous PVP granulation.
Claims 1, 9 and 11 cover three different process architectures: pre-mixed active granulation, active suspension granulation and PVP solid-solution granulation.
Claims 27 through 38 target Daliresp-like tablets containing 0.125 mg, 0.25 mg or 0.5 mg roflumilast.
The patent is strongest against a generic that copies the commercial composition and wet-granulation process.
Direct compression, dry granulation, non-PVP binders and crystalline-active formulations may provide design-around paths.
The ordinary public patent-term endpoint is reported as August 16, 2028, subject to applicable term adjustment and Orange Book treatment.
No biosimilar pathway applies because roflumilast is a small molecule.
Paragraph IV risk depends on the applicant's actual process, not only the final ingredient list.
The US patent must be analyzed separately from compound, method-of-use, topical-formulation and foreign-family rights.

FAQs About US Patent 8,431,154

Does US 8,431,154 cover all roflumilast tablets?

No. It covers specified immediate-release oral tablets or pellets produced through aqueous PVP granulation and containing the claimed roflumilast compound or related form.

Can a direct-compression roflumilast tablet avoid the patent?

Potentially. Direct compression may avoid the literal granulation limitations, but the complete claim construction and product-by-process analysis must be assessed against the actual product and manufacturing record.

Does the patent cover roflumilast topical foam?

No. The claims are directed to oral tablets or pellets. Topical roflumilast products require a separate patent and regulatory analysis.

Are the 0.125 mg and 0.25 mg strengths protected?

Yes, claims 27, 28, 33, 34, 36 and 37 specifically recite those strengths in the claimed composition and process contexts.

Is a PVP solid dispersion always required?

No. A PVP solid solution is required by claim 11 and related claims, but claims 1 and 9 cover other aqueous-PVP granulation configurations that do not necessarily require a solid dispersion.

References

U.S. Food and Drug Administration. (2011). Daliresp (roflumilast) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/022522s000lbl.pdf
Abbott Laboratories v. Sandoz, Inc., 566 F.3d 1282 (Fed. Cir. 2009).
Amgen Inc. v. F. Hoffman-La Roche Ltd., 580 F.3d 1340 (Fed. Cir. 2009).
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
United States Patent and Trademark Office. (2013). U.S. Patent No. 8,431,154, Pharmaceutical formulations containing roflumilast. https://patents.google.com/patent/US8431154B2/en

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Germany	102 07 160	Feb 20, 2002
	02003811	Feb 20, 2002

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	038527	⤷ Start Trial
Austria	550038	⤷ Start Trial
Australia	2003206924	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,431,154

Summary for Patent: 8,431,154