Details for Patent: 6,773,720

Summary for Patent: 6,773,720

Title:	Mesalazine controlled release oral pharmaceutical compositions
Abstract:	Controlled-release oral pharmaceutical compositions containing as active ingredient 5-amino-salicylic acid, comprising: a) an inner lipophilic matrix consisting of substances with a melting point below 90° C. in which the active ingredient is at least partly inglobated; b) an outer hydrophilic matrix in which the lipophilic matrix is dispersed; c) optionally other excipients.
Inventor(s):	Roberto Villa, Massimo Pedrani, Mauro Ajani, Lorenzo Fossati
Assignee:	Cosmo Technologies Ltd
Application Number:	US10/009,491
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,773,720
Patent Claim Types: see list of patent claims	Composition; Formulation; Compound; Process; Dosage form;

Executive summary U.S. Patent 6,773,720 centers on a controlled-release oral matrix architecture for 5-aminosalicylic acid (5-ASA): a dual-matrix system with (i) an inner lipophilic phase made from low-melting (<90°C) lipid excipients and (ii) an outer hydrophilic polymer/gum phase, with 5-ASA dispersed in both regions at high load (80–95 wt%). Claims also cover manufacturing by melt granulation (including kneading/extrusion/granulation paths) and final oral dosage forms (tablet/capsule “mintablets”). The estate is conceptually narrow on (a) structural dual-matrix dispersion of the drug in both phases, (b) the specific low-melting lipophilic excipient class, and (c) the high 80–95 wt% drug loading. While the broader concept of controlled-release 5-ASA is crowded historically, the enforceable scope of 6,773,720 is likely strongest against products that match the claimed internal architecture and dispersion/loading metrics, and weaker against systems that use different matrices (hydrogel cores, ethylcellulose/enteric coatings without inner lipophilic matrix, shell-only hydrophilic barriers, or substantially lower drug loading).

H1: U.S. Patent 6,773,720 scope, claims, and 5-aminosalicylic acid controlled-release dual-matrix patent landscape

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What does U.S. Patent 6,773,720 claim for controlled-release 5-aminosalicylic acid?

Short answer: It claims oral controlled-release compositions in which 5-ASA is dispersed in both an inner lipophilic matrix and an outer hydrophilic matrix, with 5-ASA at 80–95 wt% and lipophilic components having melting points below 90°C.

Claim 1: Core scope elements that define infringement and non-infringement

Claim 1 is a structural and compositional combination claim. A product is within scope only if it satisfies all mandatory elements:

A. Drug and oral controlled-release function

• Active ingredient: 5-amino-salicylic acid (5-ASA).
• Delivery: controlled-release oral pharmaceutical composition (functional limitation).

B. Inner lipophilic matrix with defined excipient universe

• Composition: lipophilic matrix made from substances in one of the following categories:
  • unsaturated and/or hydrogenated fatty acid
  • salts, esters, or amides of fatty acids
  • fatty acid mono-, di- or triglycerides
  • waxes
  • ceramides
  • cholesterol derivatives with melting points below 90°C
• Critical qualifier: melting point below 90°C for the listed lipophilic excipients (at least as applied to cholesterol derivatives and, by claim construction, to the low-melting lipophilic excipient set used as the inner matrix material).

C. 5-ASA dispersed in both matrices (a key dual-dispersion requirement)

• Claim 1 requires 5-ASA is dispersed both in the lipophilic matrix and in the hydrophilic matrix.
• This is the central claim boundary versus many “core-in-shell” or “drug in core with inert shell” systems.

D. Outer hydrophilic matrix with defined polymer/gum universe

• Outer hydrophilic matrix consists of compounds selected from:
  • polymers/copolymers of acrylic or methacrylic acid
  • alkylvinyl polymers
  • hydroxyalkyl celluloses
  • carboxyalkyl celluloses
  • polysaccharides, dextrins, pectins, starches, derivatives
  • alginic acid
  • natural or synthetic gums

E. High drug loading

• 5-ASA amount: 80 to 95% by weight of the total composition.

F. Optional excipients

• The claim includes “optionally other excipients,” meaning infringement is still possible with additional allowed materials, provided the mandatory architecture and dispersions remain present.

Claim 2: Processing path for lipophilic dispersion

Claim 2 adds a manufacturing detail:

• “5-aminosalicylic acid is dispersed in a molten lipophilic matrix by kneading, extrusion and/or granulation.”

This targets making the inner lipophilic dispersion using mechanical dispersion into melted lipids. It does not replace the Claim 1 architectural requirements.

Claim 3: Dosage form targets

Claim 3 explicitly covers:

• tablets, capsules, and “mintablets.” This matters for enforcement because some controlled-release concepts are made as multiparticulates or coated beads; Claim 3 does not explicitly list beads, pellets, or spheroids, which may narrow direct-fit claims depending on claim interpretation.

Claim 4: Process claim tying melt granulation to final tablet/compression

Your text references Claim 4 as:

• melt granulation of at least one portion of the active ingredient with the lipophilic excipients (melting point <90°C)
• mixing resulting granules with hydrophilic excipients
• subsequent tabletting or compression

This process claim is valuable against method-attributed filings and against manufacturing site arguments, even if a competitor tries to argue dosage form differences.

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How strong is the patent estate for dual-matrix controlled-release 5-ASA like 6,773,720?

Short answer: Strength is highest for products that replicate the triple constraints: (1) inner low-melting lipophilic matrix, (2) outer hydrophilic matrix of the specified class, and (3) 5-ASA dispersed in both phases at 80–95 wt%. Weakness appears where competitors keep high-level concepts but shift to different excipient families, exclude dual dispersion, or use substantially lower drug loading.

Key infringement “tripwires”

1. Dual dispersion requirement

   • Many controlled-release systems put drug primarily in a core (often the hydrophobic phase) with a hydrophilic coating layer that is not drug-loaded. If drug is not dispersed in the hydrophilic outer matrix to the claimed extent, a design-around may avoid Claim 1.

2. 80–95 wt% drug loading

   • If a competitor uses more typical sustained-release tablet compositions with substantial polymer load, the drug percentage may fall below 80%. That would miss this limitation even if matrix architecture resembles the concept.

3. Inner low-melting excipient requirement

   • If competitors choose lipophilic excipients outside the “melting point below 90°C” parameter (for example, higher-melting waxes, fats, or structured lipids), they may avoid that limitation.

4. Specific hydrophilic polymer/gum universe

   • The outer matrix is limited to listed classes. Using other hydrophilic systems not covered (depending on claim construction) may enable non-infringement.

Practical enforcement posture implied by these claim features

• The claim is engineered to catch composition-level manufacturing and product-level testing outcomes: drug distribution analysis (inner vs outer), formulation percent assay, and excipient selection/melting point.
• Competitors can reduce risk by targeting one of the tripwires: drug distribution (exclude drug from outer matrix), drug loading, or lipophilic excipient melting profile.

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What patents protect controlled-release oral 5-aminosalicylic acid matrix systems like those in 6,773,720?

Short answer: The controlled-release 5-ASA space is populated with matrix, coating, and multiparticulate delivery patents; 6,773,720 is distinctive for its defined inner/outer matrix architecture, dual dispersion of drug across phases, and high (80–95 wt%) drug loading. Without the full document record (publication numbers, family members, and prosecution history), a complete cross-patent landscape cannot be enumerated from the claim text alone.

How to map the competitive “adjacent” patent families conceptually (without asserting specific US numbers)

• Core-only drug-loaded matrices + external coatings: often fail on “drug dispersed in both lipophilic and hydrophilic matrices.”
• Enteric-coated 5-ASA systems: may not use the claimed lipophilic inner matrix and drug-loading range.
• Polymer matrices without low-melting lipids: likely fail on inner lipophilic excipient selection.
• Multiparticulate beads or pellets: may not match dosage form dependent claims (Claim 3), depending on whether the pellets are treated as “tablets/capsules” under claim construction.

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When does U.S. Patent 6,773,720 lose exclusivity and what does that mean for generic or follow-on products?

Short answer: This depends on the patent’s statutory expiration (including filing date, patent term adjustment, and any terminal disclaimer), and on whether there are separate regulatory exclusivities tied to a specific NDA/ANDA or a 505(b)(2) product. The claim text provided does not include any filing, priority, issuance, or PTA/TDA data, and no Orange Book regulatory linkage is provided.

What is clear from the claim structure for exclusivity risk

• Because the claim is composition- and process-defined, a generic or follow-on entrant would typically attempt:
  • a non-infringing formulation design-around (change excipient families, drug distribution, or drug loading), and/or
  • a non-infringing process (avoid melt granulation as described in the process claim, where relevant), and/or
  • a legal challenge (invalidity or noninfringement) depending on the evidentiary record.

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What are the key design-around strategies to avoid infringement of claims 1–4?

Short answer: The most direct levers are (1) remove 5-ASA from the hydrophilic outer matrix, (2) reduce drug loading below 80 wt%, (3) use lipophilic materials with melting points at or above 90°C, or (4) substitute outer hydrophilic polymers/gums outside the listed categories.

Drug distribution engineering: the highest-leverage lever

• Claim 1 requires 5-ASA dispersed in both matrices.
• Design-around pattern:
  • Put 5-ASA primarily in one phase (e.g., lipophilic core) and keep outer hydrophilic phase as mostly polymer without drug dispersion.

Percent-by-weight engineering

• Claim 1 is tight: 80–95% total drug.
• Design-around pattern:
  • Increase excipient fraction (especially polymers/gums) so drug content drops under 80 wt%.

Lipophilic excipient melting-point engineering

• Claim 1 specifies low-melting (<90°C) lipid excipients.
• Design-around pattern:
  • Use higher-melting lipids/waxes outside the <90°C constraint.

Dosage form and manufacturing path considerations

• Claim 3 lists tablets, capsules, mintablets.
  • If a competitor uses beads/pellets for capsule filling, risk depends on claim interpretation.
• Claim 2 and the referenced process claim (your “step a/b”) focus on molten lipophilic dispersion using kneading/extrusion/granulation and melt granulation.
  • A competitor could adopt a different manufacturing pathway that still yields a similar architecture, but avoiding the exact melt-granulation steps would be the goal for process-claim risk reduction.

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How do Claims 2 and 4 narrow the scope compared with Claim 1?

Short answer: Claim 1 is the broadest, composition-level architecture claim. Claims 2 and 4 introduce manufacturing process specifics that can be absent even when the final product matches Claim 1.

Claim 2 (kneading/extrusion/granulation into molten lipophilic matrix)

• Narrows to a method of achieving the inner dispersion.
• A competitor can keep the final dual-matrix product concept but use alternative dispersion/processing steps, potentially avoiding Claim 2 while still risking Claim 1.

Process claim (melt granulation + mixing with hydrophilics + compression)

• Narrows to a production sequence that is typical for matrix tablets.
• Competitors using other unit operations (spray drying, fluid-bed coating, hot-melt extrusion with different intermediate steps) may avoid this exact sequence even if product characteristics resemble the claimed system.

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What evidence would matter most to litigate claim scope for 6,773,720?

Short answer: Product formulation analytics and manufacturing records. The claim is written so that infringement depends on measurable characteristics (drug percentage, excipient identity and melting point, and drug distribution across inner and outer matrices).

Product-side evidence

• quantitative assay confirming 5-ASA is 80–95 wt%
• excipient list matching the specified lipophilic and hydrophilic classes
• melting point characterization for the low-melting lipid excipients (especially where melting points are disputed)
• microscopic/analytical methods to demonstrate that 5-ASA is dispersed in both inner lipophilic and outer hydrophilic regions

Process-side evidence (for Claim 2/4)

• batch manufacturing master records
• in-process logs showing kneading/extrusion/granulation into molten lipids
• records showing melt granulation steps and subsequent mixing/tabletting

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Which competitor products are most likely at risk (and why) for 6,773,720-style controlled-release 5-ASA?

Short answer: Products that present as high-drug-load dual-matrix tablets/capsules using lipid inner matrices with low-melting lipids and hydrophilic polymer outer matrices, with drug present in both phases.

Given only the claim text, specific at-risk products cannot be identified without cross-referencing:

• the exact commercial product composition,
• the claimed 80–95 wt% loading,
• excipient identities/melting points, and
• distribution assays.

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What formulation and manufacturing elements in 6,773,720 create patentability leverage?

Short answer: The claim combines elements that are individually common in controlled-release drug delivery but that are less often co-present in one formulation:

• explicit dual dispersion of drug into both inner lipophilic and outer hydrophilic matrices, and
• very high drug loading (80–95 wt%),
• paired with a constrained lipophilic excipient melting-point profile (<90°C).

This combination can support novelty and non-obviousness arguments, especially if prior art disclosed controlled-release 5-ASA but not the same dual-dispersion architecture and loading range.

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How should you treat the patent landscape if you are pursuing licensing or freedom-to-operate?

Short answer: Focus licensing and FTO diligence on:

1. confirmation of dual-matrix architecture in finished product
2. confirmation of 5-ASA wt% within 80–95
3. excipient selection and melting points
4. drug distribution into the outer hydrophilic phase
5. process record alignment with melt granulation and molten dispersion steps

These factors map directly to Claims 1–4 and determine whether design-around is feasible at formulation level or only at process and documentation level.

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Key Takeaways

• U.S. Patent 6,773,720 is a dual-matrix controlled-release 5-ASA composition patent anchored on inner lipophilic matrices made from low-melting (<90°C) lipid excipients and outer hydrophilic polymer/gum matrices.
• The enforceable scope is defined by three high-risk limitations in Claim 1: (1) 5-ASA dispersed in both inner and outer matrices, (2) 80–95 wt% 5-ASA loading, and (3) constrained excipient melting-point and class selections.
• Claim 2 and the process claim add manufacturing pathway constraints (molten lipophilic dispersion and melt granulation), which can be used to narrow evidence needs if product architecture is ambiguous.
• Design-around is most feasible by breaking a single tripwire: dual dispersion in the outer matrix, drug loading below 80 wt%, or using lipophilic materials with melting points not falling below 90°C.

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FAQs

1. Can a dual-matrix 5-ASA product avoid infringement if 5-ASA is only in the lipophilic inner matrix?
2. How do you test whether 5-ASA is “dispersed” in the hydrophilic outer matrix for Claim 1?
3. Does using tablets versus capsules change infringement risk under the “mintablets/tablets/capsules” limitations?
4. If a product meets the composition of Claim 1 but uses a different manufacturing sequence than melt granulation, what claims remain at risk?
5. What excipient substitutions are most likely to defeat Claim 1’s defined lipophilic and hydrophilic excipient lists?

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References

1. U.S. Patent 6,773,720 (claims as provided in the prompt).

Drugs Protected by US Patent 6,773,720

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: 6,773,720

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Italy	MI99A1316	Jun 14, 1999

PCT Information
PCT Filed	June 08, 2000	PCT Application Number:	PCT/EP00/05321
PCT Publication Date:	December 21, 2000	PCT Publication Number:	WO00/76481

International Family Members for US Patent 6,773,720

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	235234
Austria	324104
Australia	5077200
Canada	2377299
China	100448448
China	1217665