Details for Patent: 8,709,478

Summary for Patent: 8,709,478

Title:	Once daily formulations of tetracyclines
Abstract:	Disclosed are once-daily formulations containing tetracyclines, especially doxycycline. Such formulations are useful, for instance, for the treatment of collagenase destructive enzyme-dependent diseases, such as periodontal disease and acne, and acute and chronic inflammatory disease states, such as rosacea and arthritis.
Inventor(s):	Rong-Kun Chang, Arash Raoufinia, Niraj Shah
Assignee:	Tcd Royalty Sub Lp
Application Number:	US13/920,538
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,709,478
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Dosage form;

US Patent 8,709,478: Scope, Claims, and US Patent Landscape for Oral Doxycycline in Rosacea

US Patent 8,709,478 claims a specific oral rosacea treatment method tied to a two-part release oral doxycycline composition: an immediate-release (IR) dose of about 30 mg doxycycline plus a delayed-release (DR) dose of about 10 mg doxycycline, for a total doxycycline amount of about 40 mg, with doxycycline stated as the sole active ingredient. The claims also constrain once-daily dosing blood exposure to defined ranges, and provide extensive formulation variable coverage through open-ended excipient selection and enumerated polymer/excipient subgroups.

What is the core claimed invention?

The claim set is method-centric: it claims treating rosacea in a mammal by administering an oral pharmaceutical composition. The invention is defined by composition architecture and dose split:

• Oral pharmaceutical composition
• Doxycycline is the sole active ingredient
• Total doxycycline is about 40 mg
• Immediate-release (IR) formulation: about 30 mg doxycycline
• Delayed-release (DR) formulation: about 10 mg doxycycline
• Optional downstream manufacturing features: controlling coat, overcoating layer, core, and combinations

The “patentable” distinction is the IR/DR split and the formulation regimen intended to drive a targeted systemic exposure profile at once-daily dosing (blood level bands in claims 3, 4, 22, 23).

What do independent claim 1 and claim 20 require (scope lock)?

Claim 1 (broadest structural anchor)

Claim 1 requires all of the following:

1. Method: treating rosacea in a mammal in need thereof by administering an oral composition.
2. Composition has 3 mandatory elements:
   • (i) IR formulation comprising about 30 mg doxycycline
   • (ii) DR formulation comprising about 10 mg doxycycline
   • (iii) pharmaceutically acceptable excipient chosen from the listed excipient categories
3. Total doxycycline amount: about 40 mg
4. Doxycycline is the sole active ingredient
5. Optional layers/components: controlling coat, overcoating layer, core, and combinations
6. Release architecture: IR + DR are both present
7. Dosage and PK constraints appear only in dependent claims (3 and 4), not in claim 1.

Claim 20 (alternative formulation emphasis, same dose split)

Claim 20 recites:

1. Same overall method for treating rosacea with an oral composition.
2. IR formulation comprises about 30 mg doxycycline
3. DR formulation comprises about 10 mg doxycycline and an enteric polymer
4. Total doxycycline about 40 mg
5. Doxycycline sole active ingredient
6. Excipients are optional in claim 20 (still limited to enumerated categories)
7. Protective coating and core are optional

Functionally, claim 20 ties the DR portion to an enteric polymer in the independent statement, while claim 1 allows the DR formulation’s enteric polymer relationship through dependent claims (claim 17 and onward).

How do the dependent claims narrow exposure, excipients, and polymers?

Blood level bands at once daily

Claims 3-4 and 22-23 define pharmacokinetic exposure:

• Claim 3: once-daily dosing gives blood doxycycline 0.1 to 1.0 μg/mL
• Claim 4: once-daily dosing gives blood doxycycline 0.3 to 0.8 μg/mL
• Claim 22: same as claim 3 (0.1 to 1.0 μg/mL)
• Claim 23: same as claim 4 (0.3 to 0.8 μg/mL)

These create a measurable functional limitation. A product designed to meet only structural dosing (30/10 mg split) but failing the claimed once-daily exposure window can potentially avoid those dependent claims.

Excipient coverage is broad but enumerated

Claim 1 and claim 20 allow a wide set of excipient functions, including:

• Binder, disintegration agent, filling agent, surfactant, solubilizer, stabilizer, lubricant, plasticizer
• plus enteric polymers as a category in claim 1’s excipient list

Claim 1 also explicitly allows enteric polymers in the excipient list, while claim 20 more directly requires an enteric polymer in the DR formulation.

Binder selections (examples within the claim)

Claim 6 (and claim 25 in claim 20 chain) limits to enumerated binders:

• methylcellulose
• hydroxyethyl cellulose
• hydroxypropyl cellulose
• hydroxypropyl methylcellulose
• polyvinylpyrrolidone
• polyvinylpyrrolidone/vinyl acetate copolymer

Disintegration agents

Claim 7 (and claim 26) includes:

• cornstarch
• pregelatinized starch
• cross-linked carboxymethylcellulose
• sodium starch glycolate
• cross-linked polyvinylpyrrolidone

Filling agents

Claim 8 (and claim 27):

• lactose
• calcium carbonate
• calcium phosphate
• calcium sulfate
• microcrystalline cellulose
• dextran
• starches
• sucrose
• xylitol
• lactitol
• mannitol
• sorbitol
• sodium chloride
• polyethylene glycol

Surfactants

Claim 9 (and claim 28):

• sodium lauryl sulfate
• sorbitan monooleate
• polyoxyethylene sorbitan monooleate
• bile salts
• glyceryl monostearate

Solubilizers / pH modifiers

Claim 10 (and claim 29):

• citric acid
• succinic acid
• fumaric acid
• malic acid
• tartaric acid
• maleic acid
• glutaric acid
• sodium bicarbonate
• sodium carbonate

Stabilizers

Claim 11 (and claim 30):

• antioxidation agents
• buffers
• acids

Plasticizers

Claim 12 (and claim 31):

• acetyltriethyl citrate
• triethyl citrate
• acetyltributyl citrate
• dibutylsebacate
• triacetin
• polyethylene glycols
• propylene glycol

Lubricants

Claim 13 (and claim 32):

• talc
• colloidal silica dioxide
• magnesium stearate
• calcium stearate
• titanium dioxide
• magnesium silicate
• stearic acid
• polyethylene glycol
• leucine
• glyceryl behenate
• hydrogenated vegetable oil

Core, coating, and dosage form

Claim 14 and claim 15:

• core may comprise sugar spheres or microcrystalline spheres
• overcoating layer may be a protective coating, color coating, or both

Claim 16 and claim 34 define dosage forms:

• granule, tablet, pellet, powder, sachet, capsule, gel, dispersion, suspension

Claim 17 and claim 35:

• DR formulation comprises at least one enteric polymer

Claim 18 and claim 36 enumerate DR enteric polymer options:

• cellulose acetate phthalate
• hydroxypropyl methylcellulose phthalate
• polyvinyl acetate phthalate
• hydroxypropyl methylcellulose acetate succinate
• cellulose acetate trimellitate
• hydroxypropyl methylcellulose succinate
• cellulose acetate succinate
• cellulose acetate hexahydrophthalate
• cellulose propionate phthalate
• copolymers including:
  • methylmethacrylic acid + methyl methacrylate
  • methyl acrylate + methylmethacrylate + methacrylic acid
  • methylvinyl ether + maleic anhydride
  • ethyl methyacrylate-methylmethacrylate-chlorotrimethylammonium ethyl acrylate copolymer
  • zein
• shellac
• poly(methacrylic acid-co-ethyl acrylate) 1:1
• combinations thereof

DR form factor

Claim 19 and claim 37: DR formulation in the form of granules, pellets, or a tablet.

What is the practical claim coverage boundary (design-around map)?

High-risk infringement zone

A product is at risk if it meets all of the following simultaneously:

1. Rosacea treatment method
2. Oral composition
3. Doxycycline sole active
4. Total doxycycline about 40 mg
5. Two release forms in one regimen:
   • IR about 30 mg
   • DR about 10 mg
6. Once-daily dosing PK if targeting dependent claims (0.1-1.0 or 0.3-0.8 μg/mL bands)

Lower risk options (conditional)

• If the DR portion does not include an enteric polymer where claim coverage depends on the independent statement (notably claim 20), it may avoid claim 20’s strict structure, but not necessarily claim 1 depending on whether dependent claim sets are satisfied.
• If dosing is not once-daily, dependent PK claims (3-4, 22-23) are potentially avoidable, though method/structural claims could still be implicated.
• If the total daily doxycycline differs from “about 40 mg” or the split differs from “about 30 mg IR + about 10 mg DR,” the risk drops at the independent claim level.

Claim set structure: what is being patented (and what is left open)?

The scope is a composite of:

• Quantity constraints: about 30 mg IR + about 10 mg DR, total about 40 mg
• Actives constraint: doxycycline is sole active ingredient
• Release profile architecture: IR and DR both present
• Optional manufacturing structures: coatings and cores
• Extensive formulation excipient and polymer lists inside dependent claims, giving significant flexibility to meet those dependent pathways
• Functional PK limitations inside dependent claims at once daily

Notably, the independent claim does not require any specific enteric polymer species in claim 1 itself; it does so via dependent claims (and claim 20 directly).

Patent landscape: how to read competitive positioning around US 8,709,478

Without the full prosecution record, related family members, and the patent’s publication/grant timeline, the landscape can be characterized only at the claim-scope level. The competitive field is constrained by what the claims cover:

Where other rosacea doxycycline products tend to fall

Most potential competitors can be grouped by formulation strategy:

1. Single immediate-release doxycycline regimens
   • Generally miss the IR/DR split and the delayed-release component at claim level.
2. Delayed-release-only formulations
   • Generally miss the IR component at claim level.
3. Two-phase formulations with different daily dose totals or different IR/DR split
   • Likely avoid the independent claim structural anchor.
4. Two-phase formulations that match dose split but use different actives
   • Avoid doxycycline sole active requirement.
5. Two-phase formulations matching dose split and actives but designed to alter PK profile
   • May avoid dependent PK claims while still risking structural claims.

Litigation and invalidity vectors that matter given the claim language

The strongest business-relevant vectors implied by the claim structure are:

• Exposure window dependency: PK-dependent claims create a testable infringement axis.
• Enteric polymer enumeration: while broad, it is still a defined universe of polymer types in dependent claim lists.
• “About” dose language: creates claim interpretation risk for parties relying on marginal dose differences.
• Method claim posture: competitors can attempt to avoid method usage claims by changing the label indication, though direct product infringement for “method of use” varies by jurisdiction and enforcement strategy.

Freedom-to-operate framing for R&D and product teams

From a development standpoint, the claims define a “box” around formulation and usage:

Key technical design constraints

• Maintain total doxycycline close to 40 mg
• Maintain IR about 30 mg + DR about 10 mg
• Maintain doxycycline as sole active
• If pursuing into dependent claim territory, tune enteric polymer choice and target once-daily plasma doxycycline bands
• If aiming for safe clearance, avoid satisfying dependent PK ranges when possible by altering regimen timing, split, or formulation release behavior.

What does the claim language imply for enforceability and enforceable scope?

• The invention is not a generic doxycycline rosacea method; it is an oral regimen with a defined IR/DR dose split and a defined total doxycycline amount.
• The dependent claims broaden formulation flexibility by listing excipients and polymer types, which can make it easier to find a claim path if a product uses standard tablet technologies.
• The PK claims add a quantitative measurement hook. If plasma levels fall outside the bands, infringement for those dependent claims is more contestable.
• Claim 20 tightens one axis by requiring an enteric polymer in the DR formulation at the independent claim level, which can tighten competitive risk for formulations using enteric polymers.

Key Takeaways

1. US 8,709,478 claims a rosacea treatment method using an oral doxycycline composition with a defined IR/DR split: about 30 mg IR + about 10 mg DR, totaling about 40 mg, with doxycycline as the sole active ingredient.
2. Dependent claims add once-daily blood level constraints: 0.1 to 1.0 μg/mL and 0.3 to 0.8 μg/mL, creating a measurable infringement axis.
3. The formulation scope is wide in practice because it enumerates many binders, disintegration agents, fillers, surfactants, solubilizers, stabilizers, plasticizers, lubricants, and enteric polymer species that can support different embodiments.
4. Competitive design-around is most plausibly achieved by changing dose total, IR/DR split, actives, release architecture, or once-daily exposure profile, rather than by swapping inactive excipients alone.

FAQs

1. Is US 8,709,478 a product patent or a method-of-use patent?

It is a method for treating rosacea claim set, defined by administering a particular oral composition structure and regimen.

2. What is the central dose structure that drives claim scope?

An oral composition with IR about 30 mg doxycycline and DR about 10 mg doxycycline, totaling about 40 mg.

3. Does the patent require an enteric polymer in all embodiments?

Claim 1 allows DR with excipients generally, while claim 20 independently requires an enteric polymer in the DR formulation; further dependent claims (17 and 35) also require DR to comprise at least one enteric polymer.

4. What determines infringement of the dependent PK claims?

Meeting the once-daily blood doxycycline concentration ranges in claims 3-4 and 22-23 (0.1 to 1.0 μg/mL; 0.3 to 0.8 μg/mL).

5. Can changing excipients avoid the claims?

Excipient swaps alone may not avoid independent claim scope because excipients are broadly allowed categories in the claim language; avoiding the IR/DR split, total dose, doxycycline-only active requirement, or DR enteric/PK constraints is more decisive.

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References

[1] US Patent 8,709,478. “Method for treating rosacea with immediate-release and delayed-release doxycycline.” Claims as provided in user input.

Drugs Protected by US Patent 8,709,478

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 8,709,478

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	2521885
Canada	2803922
Canada	2894736
Denmark	1615622
Denmark	2204168