Details for Patent: 6,066,339

Summary for Patent: 6,066,339

Title:	Oral morphine multiparticulate formulation
Abstract:	An oral morphine multiparticulate formulation for once-daily administration to a patient, comprising sustained release particles each having a core containing water soluble morphine and an osmotic agent, the core being coated with a rate-controlling polymer coat comprised of ammonio methacrylate copolymers in an amount sufficient to achieve therapeutically effective plasma levels of morphine over at least 24 hours in the patient.
Inventor(s):	Paul Stark, Sean Cunningham, Jagathesan Moodley
Assignee:	Alkermes Pharma Ireland Ltd
Application Number:	US08/977,965
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,066,339
Patent Claim Types: see list of patent claims	Formulation; Compound;

Scope and Claims Analysis for US Patent 6,066,339: Oral Once-Daily Multiparticulate Morphine with Osmotic Agent and Ammonio Methacrylate (USP/NF) Rate-Controlling Polymer Coat

Executive summary: US 6,066,339 claims a specific oral morphine multiparticulate sustained-release architecture for once-daily dosing. The core is water-soluble morphine + osmotic agent and is coated with a rate-controlling polymer coat of ammonia methacrylate copolymers (with functional dissolution and pharmacokinetic performance thresholds over 24 hours). Dependent claims narrow to added immediate-release morphine overlays, defined in vitro dissolution ranges, particle-population multiplicity (different dissolution profiles), steady-state exposure flattening, and multiple specific formulation parameters (organic acid identity, polymer ratio, moisture content, drying conditions, dose range, encapsulation, and optional inert core with blend). The claim structure creates both (i) a strong “core + polymer coat + osmotic agent + 24-hour plasma exposure” infringement anchor and (ii) multiple high-value design-around points (polymer chemotype, osmotic agent type, multiparticulate vs other SR formats, and whether the PK/dissolution targets are met).

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What is US Patent 6,066,339 claiming about once-daily oral morphine?

Core claim theme (independent claim 1):

1. Dosage form: oral multiparticulate formulation for once-daily administration.
2. Particle structure: sustained release particles with:
   • core containing water soluble morphine + osmotic agent
   • rate-controlling polymer coat comprised of ammonia methacrylate copolymers
3. Functional performance: polymer amount sufficient for therapeutically effective plasma levels over at least 24 hours.
4. Osmotic agent restriction: osmotic agent is an organic agent.

Practical reading of claim 1’s infringement “essentials”:

• You must have (a) an oral morphine multiparticulate system,
• (b) a morphine-containing core paired with an osmotic agent that is organic,
• (c) a rate-controlling polymer coat made from ammonia methacrylate copolymers (as a polymer class),
• and (d) the coat quantity must be set such that the formulation produces morphine exposure of the required duration (at least 24 hours).

Scope pressure points:

• Claim 1 does not require exact dissolution percentages, specific polymer ratio, or specific organic acid identity, but it does require ammonia methacrylate copolymers and an organic osmotic agent.
• “Therapeutically effective plasma levels” is functional; in litigation, claim construction and evidence typically focus on the pharmacokinetic readouts elsewhere in the claims (claims 5–12 and 27) to define what “sufficient to achieve” means.

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Which elements of claim 1 are most likely to drive infringement?

1) “Ammonia methacrylate copolymers” polymer coat

• Independent claim 1 is anchored to this polymer class as the rate-controlling polymer coat.
• Dependent claim 16 further narrows to a specific ratio 5:95 described as “Ammonio Methacrylate Copolymers as described in USP/NF in a ratio of 5:95.”

Infringement implication: Replacing ammonia methacrylate copolymers with a different swellable/ER polymer system (even if it achieves similar PK) risks avoiding claim coverage if the polymer is not literally or equivalently “ammonia methacrylate copolymers” (and particularly if dependent claim 16 is asserted).

2) Osmotic agent must be “an organic agent”

• Claim 1 limits osmotic agent to organic.
• Dependent claims 17–18 narrow to organic acids and specifically fumaric acid.

Infringement implication: Use of inorganic osmolytes or different osmotic mechanisms that do not qualify as “organic agent” can be a design-around path, subject to claim construction of “osmotic agent” and “organic agent.”

3) Multiparticulate once-daily format with 24-hour plasma levels

• Claim 1 requires “once-daily administration” and sustained plasma over at least 24 hours.

Infringement implication: Formats that are not multiparticulate (e.g., monolithic ER tablets) can avoid if claim language is construed strictly. Formats that are multiparticulate but deliver a significantly shorter PK tail could also avoid.

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How do the dependent claims expand scope to immediate-release overlays and multiple particle populations?

Immediate-release coating and immediate-release particle fraction

• Claim 2: portion or all sustained release particles further comprise an immediate release coating applied onto the rate-controlling polymer coat, where the immediate release coating comprises water soluble morphine.
• Claim 3: formulation further comprising a portion of immediate release particles each comprising a core of water soluble morphine.

Scope effect: These claims cover “biphasic” morphine release strategies: ER backbone plus IR for rapid onset.

Multiple sustained-release particle populations

• Claim 4: at least two populations of sustained release particles with different in vitro dissolution profiles.

Scope effect: Supports “blended populations” strategies, enabling both flattened plasma profiles and targeted initiation/maintenance release kinetics.

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What pharmacokinetic performance thresholds are claimed?

Peak-relative duration metrics

• Claim 5: duration where plasma level ≥ 50% peak is 20 hours or greater.

• Claim 6: duration is 24 hours or greater.

• Claim 7: duration is 30 hours or greater.

• Claim 8: duration where plasma level ≥ 75% peak is 6 hours or greater.

• Claim 9: ≥ 12 hours.

• Claim 10: ≥ 18 hours.

Steady-state flattening over a 24-hour dosing period

• Claim 11: at steady state, plasma level over 24 hours is ≥ 50% of peak.
• Claim 12: at steady state, duration where plasma level over the 24-hour dosing period is ≥ 75% of peak is 12 hours or greater.

European-style additional independent claim concept (claim 27)

• Claim 27: formulation characterized by rapid onset of action and a substantially flat morphine plasma profile (with osmotic agent being an organic acid).

Scope effect: The PK metrics create measurable endpoints that can be tested in product development and can become central in infringement and validity analyses.

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What dissolution profiles are protected (in vitro release percent windows)?

Dissolution profile A

• Claim 13:
  • 3 to 25% released after 1 hour
  • 5 to 35% after 4 hours
  • 25 to 65% after 9 hours
  • 35 to 75% after 12 hours
  • at least 70% after 24 hours

Dissolution profile B

• Claim 14:
  • 10 to 15% after 1 hour
  • 15 to 30% after 4 hours
  • 35 to 50% after 9 hours
  • 45 to 65% after 12 hours
  • at least 80% after 24 hours

Scope effect: These dependent claims act like “numerical guardrails.” Even if a competitor adopts the same general architecture (ammonia methacrylate coat + morphine core + organic osmotic agent), missing these dissolution bands can weaken assertions of specific dependent claims (though claim 1 may still be asserted on PK over 24 hours).

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What composition and processing parameters are explicitly claimed?

Particle fraction

• Claim 15: greater than 80% of the formulation comprised of sustained release particles.

Polymer ratio to USP/NF-defined ammonio methacrylate copolymer

• Claim 16: polymer coat contains Ammonio Methacrylate Copolymers described in USP/NF in a ratio of 5:95.

Organic acid identities

• Claim 17: organic acid selected from fumaric, adipic, ascorbic, citric, tartaric, lactic, malic, succinic.
• Claim 18: fumaric acid.

Core ratios

• Claim 19: water soluble morphine and osmotic agent present in core in ratio of 1:1.

Morphine salt

• Claim 20: water soluble morphine is morphine sulfate or a hydrate.

Moisture content and equilibration/drying

• Claim 21: moisture content about 3–6% by weight.
• Claim 22: equilibrated at ambient or dried at humidified conditions prior to coating to obtain moisture content about 3–6%.
• Claim 23: sustained release particles following application of coat dried at 40–50°C and 30–60% RH.

Dose range

• Claim 24: contains 10 mg to 200 mg of morphine sulfate (or equivalent).

Encapsulation and inert core options

• Claim 25: formulation is encapsulated.
• Claim 26: core comprises an inert core with a blend of morphine + osmotic agent applied.

Scope effect: These parameters define multiple nested layers of narrower claim coverage. From a freedom-to-operate perspective, they offer alternative “knockout” surfaces: a competitor can change polymer ratio, salt form, moisture management, drying envelope, or core construction to avoid dependent claim match.

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What does claim 27 add beyond claim 1 (rapid onset + flat plasma profile)?

Claim 27 is a second independent claim set with additional characterization:

• It again requires sustained release particles with:
  • core containing water soluble morphine + organic acid osmotic agent
  • rate-controlling polymer coat of ammonia methacrylate copolymers
  • and morphine plasma profile attributes: rapid onset and substantially flat morphine plasma profile.

Scope effect: It targets end-user pharmacodynamic goals that align with the IR overlay concepts and multiple dissolution populations, but framed as a “characterised by” PK profile. In litigation, characterization claims can be argued as requiring both structural features (the composition/particle requirements) and performance proof (rapid onset and flat profile).

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How strong is the patent estate structure implied by these claims?

Strength signals from the claim set

1. Single-scheme architecture: Core polymer chemistry + osmotic system + multiparticulate ER layout is consistent across independent claims.
2. Functional performance reinforcement: Dependent claims embed measurable PK and dissolution numbers.
3. Multiple narrow fallbacks: Even if broad elements are contested, dependent claims provide fallback coverage around specific polymer ratios, acids, moisture handling, and IR overlays.

Likely claim-scope attack surfaces

• Claim 1 polymer identity: If a competitor uses a non-ammonio methacrylate polymer blend, the broad independent anchor is undermined.
• Organic osmotic agent limitation: Changing osmotic agent chemotype (or mechanism) can break an element.
• Multiparticulate requirement: Switching to different unit dose format can avoid.
• PK/dissolution dependent claims: Competitors can tune release to fall outside the numeric ranges for dissolution and peak-relative duration, reducing dependent claim capture.

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What design-around strategies are suggested by the claim language?

1) Polymer design-around

• Replace ammonia methacrylate copolymers (including the USP/NF “5:95” ratio) with another ER polymer that controls release without using the claimed polymer chemistry.

2) Osmotic system design-around

• Use non-organic osmotic agents or a non-organic-acid osmotic approach.

3) Structural design-around

• Use monolithic ER rather than multiparticulate.
• Use different core architecture (though claim 26 covers inert core blends, so merely using an inert core does not avoid if other elements remain).

4) Performance tuning design-around

• For dependent claims 5–14 and 11–12: tune dissolution and PK such that release/steady-state profiles fall outside the claimed thresholds (while maintaining acceptable clinical performance).

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How do these claims map to practical generic or license risk?

Generic entry risk is element-driven:

• A morphine once-daily multiparticulate ER product with ammonia methacrylate copolymer coatings and an organic osmotic agent in the core sits closest to the claim envelope.
• Products with similar clinical outcomes but different polymer chemotypes or osmotic agents have better risk positioning against the broad independent claim, though they may still face allegations under doctrine-of-equivalents theories depending on claim construction in the relevant litigation history.

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Key Takeaways

• US 6,066,339 claims a tightly defined morphine once-daily multiparticulate sustained-release system built from (i) water-soluble morphine + organic osmotic agent in the core, and (ii) a rate-controlling coat of ammonia methacrylate copolymers.
• The claim set is reinforced by measurable PK and dissolution endpoints: peak-relative duration (50% and 75% of Cmax), steady-state flatness, and time-point dissolution windows.
• Dependent claims add high-specificity “safety rails” around immediate-release overlays, multiple particle populations, polymer ratio (5:95 USP/NF), specific organic acids (including fumaric), core morphine:acid ratio (1:1), and moisture/drying conditions.
• The most direct design-arounds are to change at least one of the anchor elements: polymer chemistry, osmotic agent type, or multiparticulate structure, then ensure tuning does not satisfy the numeric PK/dissolution-dependent limitations.

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FAQs

1. What would avoid infringement of US 6,066,339 if a product is once-daily morphine but uses a different ER polymer than ammonia methacrylate copolymers?
2. Do the dissolution-range dependent claims (13 and 14) require exact matching, or can partial overlap still trigger infringement?
3. How does the “rapid onset” characterization in claim 27 interact with immediate-release coatings or immediate-release particle fractions?
4. If a product uses fumaric acid as the osmotic agent, does that automatically align with dependent claim coverage or are other elements still necessary?
5. What is the highest-risk competitor profile for US 6,066,339 in the US oral once-daily morphine market (multiparticulate, ER-coated, organic osmotic core)?

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References

1. US Patent 6,066,339 (claims as provided by user).

Drugs Protected by US Patent 6,066,339

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 6,066,339

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	239454
Australia	5408098
Canada	2306333
Canada	2558783
Germany	69721845
Denmark	1023051
European Patent Office	1023051