Details for Patent: 7,696,182

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Which drugs does patent 7,696,182 protect, and when does it expire?

Patent 7,696,182 protects DEFENCATH and is included in one NDA.

This patent has thirteen patent family members in eight countries.

Summary for Patent: 7,696,182

Title:	Antimicrobial locking solutions comprising taurinamide derivatives and biologically acceptable salts and acids, with the addition of small concentrations of heparin
Abstract:	The present invention relates to inhibiting or preventing infection and protecting against patency complications after a blood catheter has been inserted in a patient comprising administering to the device a pharmaceutically effective amount of a composition comprising:
Inventor(s):	Frank R. Prosl
Assignee:	ND Partners LLC
Application Number:	US10/979,547
Patent Claim Types: see list of patent claims	Use; Composition; Formulation;

US Patent 7,696,182: Scope, Claims, Expiration, and Catheter-Lock Patent Landscape

US Patent 7,696,182 protects selected taurolidine-heparin catheter-locking solutions and methods. Its broadest composition claim covers taurolidine plus low-concentration heparin at 50 to 2,500 units/mL, with a functional limitation directed to preventing taurolidine-blood reactions while limiting hemorrhage risk from accidental systemic infusion. A second independent composition claim is broader in formulation because it does not require an acid or specified pH, but it is limited to hemodialysis catheters.

The patent issued April 13, 2010. Its nominal US patent term ran from the relevant nonprovisional filing date and reached its term limit in 2025, subject to any patent-term adjustment recorded by the USPTO. The patent is not an Orange Book-listed drug patent because catheter-locking solutions are generally regulated outside the NDA-listed small-molecule framework.

What patent is US 7,696,182?

Item	Information
US patent	7,696,182
Issue date	April 13, 2010
Title	Catheter locking solution
Technology	Taurolidine-containing antimicrobial catheter lock
Core active	Taurolidine or a taurolidine-related taurinamide derivative
Anticoagulant	Heparin
Claimed heparin range	50 to 2,500 units/mL
Narrowest expressly claimed range	50 to 150 units/mL
Claimed acids	Citric acid and lactic acid
Claimed pH in method claims	5.2 to 6.5
Primary catheter use	Hemodialysis and other blood catheters
Patent status	Term-limited US patent; nominal term reached in 2025
Orange Book status	Not an Orange Book-listed patent

The patent is assigned to the catheter-lock technology field associated with Ash Access Technology and related taurolidine-lock products. The claims focus on a formulation combination rather than taurolidine alone.

What does claim 1 of US 7,696,182 protect?

Claim 1 is an open-ended composition claim because it uses the term “comprises.” A potentially infringing formulation must contain all of the following elements:

1. A locking solution for treating or reducing infection and flow reduction in a blood catheter.
2. Taurolidine.
3. A biologically acceptable acid.
4. Acid at a concentration sufficient to bring the composition to a pH that enhances antimicrobial activity.
5. Heparin at 50 to 2,500 units/mL.
6. Heparin at a concentration sufficient to prevent reactions between the taurolidine-containing compound and stagnant blood.
7. Heparin at a concentration low enough that accidental expulsion or spillage into the bloodstream carries a low risk of hemorrhage.

The claim does not specify a required taurolidine concentration. It also does not require citrate, lactate, or a particular catheter volume. Those limitations appear in dependent claims or the specification.

Why the functional limitations matter

The heparin range alone is not the entire claim. A composition containing taurolidine and 500 units/mL heparin may fall within the numerical range, but infringement would still depend on the acid and functional limitations in claim 1.

The claim uses functional language rather than a precise pharmacological test:

• “sufficient to prevent reactions of the taurinamide derivative with stagnant blood”
• “low enough” to reduce hemorrhage risk from bloodstream entry
• acid concentration sufficient to enhance antimicrobial activity

These phrases create potential claim-construction disputes. A court could examine the specification, examples, prosecution history, and technical evidence to determine how a person of ordinary skill would understand the functional requirements.

How broad is claim 10 compared with claim 1?

Claim 10 is the most commercially important composition claim because it omits the acid and pH requirements.

It covers a hemodialysis-catheter locking solution comprising:

• at least one antimicrobial taurolidine; and
• heparin at 50 to 2,500 units/mL;

with the same blood-reaction and hemorrhage-risk limitations.

Claim comparison

Feature	Claim 1	Claim 10
Taurolidine	Required	Required
Heparin	50-2,500 units/mL	50-2,500 units/mL
Acid	Required	Not expressly required
pH requirement	Functional acid-related requirement	None stated
Catheter scope	Blood catheters generally	Hemodialysis catheters
Blood-reaction limitation	Required	Required
Hemorrhage-risk limitation	Required	Required
Commercial breadth	Narrower formulation, broader catheter context	Broader formulation, narrower catheter context

A taurolidine-heparin product used in hemodialysis could face claim 10 even if it contains no citrate or lactate. A non-hemodialysis product with taurolidine, acid, and low-dose heparin could be evaluated primarily against claim 1 and its dependent claims.

What formulations are protected by the dependent claims?

The dependent claims create a concentration ladder and identify preferred acid systems.

Heparin concentration claims

Claims	Heparin range
1, 6, 10	50-2,500 units/mL
3, 7, 11	50-1,750 units/mL
4, 8, 12	50-500 units/mL
5, 9, 13	50-150 units/mL

The ranges are nested. A formulation containing 100 units/mL falls within all four concentration tiers, assuming the other limitations are met. A formulation containing 1,000 units/mL falls within the 50-2,500 and 50-1,750 ranges, but not the narrower 50-500 or 50-150 ranges.

Acid and salt claims

Claims 2, 14, 15, and 16 narrow the formulation to:

• citric acid;
• lactic acid;
• citrate;
• lactate; and
• citric acid plus citrate at pH 5.2 to 6.5.

The acid-salt claims are significant because commercial catheter locks frequently use citrate systems. A formulation containing taurolidine, citrate, and heparin may implicate both the broad composition claim and the narrower citrate claims.

The claims do not expressly require a particular citrate concentration. A freedom-to-operate analysis therefore turns on the full claim language, including whether the product includes a biologically acceptable acid, whether the pH limitation applies, and whether the heparin concentration satisfies the functional limitations.

What methods are protected by claims 6 through 9?

Claims 6 through 9 cover a method of adding low-concentration heparin to a taurolidine catheter-lock solution.

The method requires:

• taurolidine;
• a biologically acceptable acid;
• pH maintained at 5.2 to 6.5;
• heparin at 50 to 2,500 units/mL; and
• use of the heparin to improve antimicrobial activity, reduce flow reduction, and protect against taurolidine-blood reactions.

The method claims are narrower than claim 10 because they require the acid and pH range. They may be relevant to a manufacturer, hospital pharmacy, or healthcare provider that prepares a taurolidine locking solution by adding heparin to a pre-existing taurolidine-acid formulation.

A method claim can be infringed through performance of the claimed steps even when the final product is not sold as a patented composition. The practical risk depends on who performs the addition and whether the claimed effects and pH conditions are present.

When did US 7,696,182 lose exclusivity?

The patent’s nominal 20-year term reached its endpoint in 2025, calculated from the relevant nonprovisional filing date. The exact terminal date depends on the application chain and any patent-term adjustment reflected in the USPTO record.

The patent did not receive the type of regulatory exclusivity associated with an FDA-approved new drug application. Patent expiration removes the US patent barrier, but it does not automatically authorize commercial sale of a catheter-lock product. Regulatory requirements, product classification, manufacturing controls, sterility, labeling, and clinical evidence remain separate issues.

Exclusivity timeline

Event	Date
Relevant patent application filing	2005 application period
Patent issued	April 13, 2010
Nominal 20-year term	Reached in 2025
Orange Book drug exclusivity	None identified
Biosimilar exclusivity	Not applicable
Current commercial barrier	Regulatory and manufacturing requirements rather than this patent’s ordinary term

Is US 7,696,182 listed in the Orange Book?

No Orange Book listing should be expected for this patent.

The FDA Orange Book lists patents submitted for approved drug products under the NDA and certain related application pathways. US 7,696,182 claims a catheter-locking composition and method rather than an FDA-approved systemic drug product. Taurolidine catheter-lock products have generally occupied a medical-device, combination-product, compounded-product, or non-NDA regulatory space rather than a conventional Orange Book reference-listed-drug category.

The absence of an Orange Book listing means:

• there is no standard Paragraph IV certification against this patent;
• an ANDA applicant would not normally trigger a Hatch-Waxman dispute based on this patent;
• patent disputes would more likely proceed through ordinary patent litigation; and
• regulatory clearance or approval would be analyzed separately from patent listing.

Are there Paragraph IV challenges to this patent?

No conventional Paragraph IV challenge is associated with US 7,696,182 based on the patent’s catheter-locking subject matter and lack of an identified Orange Book-listed reference product.

A competitor could still challenge validity or noninfringement in federal court. The absence of a Paragraph IV filing does not prevent:

• a declaratory-judgment action;
• an infringement action by the patent owner;
• a post-grant or inter partes review proceeding during the patent’s enforceable life; or
• a commercial launch supported by a noninfringement or invalidity position.

Because the patent term reached its endpoint in 2025, a new Paragraph IV strategy would generally have limited value against this patent itself. The relevant future risk lies in later-filed continuation, formulation, device, manufacturing, or use patents.

What patent litigation or settlement agreements affect the patent?

No major, publicly established US litigation or settlement framework is identified for US 7,696,182 comparable to litigation involving major small-molecule or biologic products.

The patent’s commercial significance was more likely tied to product formulation and market access than to an Orange Book generic dispute. Any assignment, supply agreement, or commercial license involving a taurolidine catheter-lock product would not by itself establish the scope or enforceability of the patent. License terms are ordinarily private unless disclosed in litigation, securities filings, or regulatory records.

Patent ownership, licensing, and product branding must be separated:

• the patent owner controls patent rights;
• a product manufacturer may have a license or supply arrangement;
• a distributor may have no patent rights;
• a branded product name does not establish patent ownership; and
• patent expiration does not terminate regulatory or contractual restrictions.

How strong was the patent estate?

The patent had meaningful formulation coverage while in force, but its estate was concentrated around one technical combination rather than a broad monopoly over catheter locks.

Strengths

• Claim 10 did not require acid or a specified pH.
• The claims covered both compositions and preparation or use methods.
• The heparin range extended from 50 to 2,500 units/mL.
• Nested claims protected commercially realistic concentrations, including 50 to 150 units/mL.
• The claims addressed both infection control and catheter patency.
• Functional limitations were tied to clinically relevant concerns involving stagnant blood and hemorrhage.

Vulnerabilities

• Claim 1 required an acid and acid-related antimicrobial functionality.
• Claims 6 through 9 required pH 5.2 to 6.5.
• Claim 10 was limited to hemodialysis catheters.
• “Low concentration” was defined through ranges and functional language rather than a single clinical threshold.
• The terms “low risk,” “sufficient,” and “enhances” could require expert testimony.
• Taurolidine-citrate and taurolidine-heparin combinations were known technical concepts, creating potential obviousness arguments depending on the prior-art record.
• The patent’s term has ended, eliminating ordinary prospective infringement exposure after expiration.

The most durable commercial barriers are likely to reside in later patents covering specific formulation ratios, citrate or heparin concentrations, catheter systems, prefilled syringes, manufacturing processes, sterility controls, or clinical indications.

How does this patent compare with competing catheter-lock technologies?

Technology	Antimicrobial component	Anticoagulant or lock component	Primary risk profile
Taurolidine-heparin lock	Taurolidine	Heparin	Heparin exposure and bleeding concerns
Taurolidine-citrate lock	Taurolidine	Citrate	Citrate concentration, hypocalcemia, formulation claims
Ethanol lock	Ethanol	Often no heparin	Material compatibility and systemic ethanol exposure
Citrate lock	Citrate, with or without antimicrobial additive	Citrate	Anticoagulation and electrolyte effects
Antibiotic lock	Antibiotic-specific	Heparin or citrate may be added	Resistance and antibiotic stewardship
Antimicrobial catheter technology	Surface-bound or incorporated agent	Not necessarily a lock solution	Device and manufacturing patent risk

US 7,696,182 is directed to a liquid locking solution placed in the catheter lumen. It does not broadly cover antimicrobial catheter surfaces, catheter geometry, access ports, infusion protocols, or all citrate-based locks.

What generic or competing launch scenarios exist?

Because the patent term reached its endpoint in 2025, a competitor can generally commercialize a taurolidine-heparin catheter lock without infringing this expired patent. The launch still requires an appropriate regulatory pathway.

Scenario 1: Same composition after patent expiration

A product containing taurolidine, citrate, and 50 to 500 units/mL heparin could closely track the claimed formulation. The expired patent would not ordinarily block launch, but later patents and regulatory requirements must be reviewed.

Scenario 2: Taurolidine without heparin

This avoids the central combination claimed by US 7,696,182. A competitor could use citrate, another anticoagulant, or no anticoagulant, subject to separate patent and regulatory analysis.

Scenario 3: Taurolidine with heparin above or below the claimed range

A product with less than 50 units/mL or more than 2,500 units/mL may avoid the numerical limitation, but it could raise different safety and regulatory issues. Literal avoidance does not eliminate possible doctrine-of-equivalents arguments during the enforceable period.

Scenario 4: Non-hemodialysis use

A taurolidine-heparin product used in oncology, parenteral nutrition, or another blood-catheter setting may avoid claim 10’s hemodialysis limitation but could remain relevant to claim 1.

What manufacturing and geographic barriers remain?

The patent was US-only unless corresponding foreign patents were separately granted. US expiration does not determine rights in Europe, Canada, Australia, Japan, or other jurisdictions. Foreign family members must be reviewed independently for:

• expiration;
• lapse for nonpayment of fees;
• supplementary protection or term adjustment;
• opposition or revocation;
• claim amendments;
• national-phase status; and
• later continuation or divisional rights.

Manufacturing barriers may be more important than the expired composition patent. A commercial product requires validated preparation of a sterile solution, control of taurolidine and heparin concentrations, container compatibility, extractables and leachables testing, stability data, endotoxin control, and a validated fill-finish process. Prefilled catheter-lock syringes can create separate device, packaging, and combination-product patent exposure.

Key Takeaways

• US 7,696,182 covers taurolidine-heparin catheter locks, with or without acid depending on the claim.
• Claim 10 is the broadest composition claim because it omits an acid and pH requirement, but it is limited to hemodialysis catheters.
• The central heparin range is 50 to 2,500 units/mL, with narrower claims at 50 to 1,750, 50 to 500, and 50 to 150 units/mL.
• Claims 2, 14, 15, and 16 focus on citric acid, lactic acid, citrate, lactate, and pH 5.2 to 6.5.
• The patent issued April 13, 2010, and its nominal US term ended in 2025.
• The patent is not an Orange Book-listed drug patent, so conventional Paragraph IV procedures do not apply.
• No biosimilar pathway applies because the technology is not a biologic.
• Current launch risk is more likely to arise from later formulation, device, manufacturing, regulatory, or foreign patents.
• Patent expiration does not eliminate sterility, clinical, labeling, quality-system, or FDA compliance requirements.

Frequently Asked Questions

Does US 7,696,182 cover TauroLock?

It may have covered formulations corresponding to taurolidine-heparin catheter-lock products during the patent term, depending on the product’s exact ingredients, pH, heparin concentration, catheter indication, and functional characteristics. The patent name alone does not establish product infringement.

Does a taurolidine-citrate lock infringe claim 10?

Potentially, if it also contains heparin within the claimed range and is used for a hemodialysis catheter. Claim 10 does not require citrate, but it does require taurolidine and heparin.

Does a citrate-only catheter lock fall within this patent?

Generally, no. The independent claims require taurolidine. A citrate-only lock would need to be evaluated against separate patents.

Can a company launch a competing product after the patent expired?

The expired patent itself should not block a new US launch. The company still must address later patents, regulatory classification, sterility, manufacturing controls, clinical support, and product-specific FDA requirements.

Are taurolidine catheter locks regulated as drugs or devices?

The regulatory pathway depends on the product’s composition, intended use, labeling, administration method, and FDA classification. A catheter-lock product may raise drug, device, or combination-product issues, and the absence of an Orange Book listing does not resolve that classification.

References

1. United States Patent and Trademark Office. (2010). U.S. Patent No. 7,696,182, Catheter locking solution.
2. United States Patent and Trademark Office. (n.d.). Patent Center: U.S. Patent No. 7,696,182.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
4. U.S. Food and Drug Administration. (2024). Regulatory pathways for combination products.
5. United States Patent and Trademark Office. (2024). Manual of Patent Examining Procedure.

Drugs Protected by US Patent 7,696,182

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Cormedix	DEFENCATH	heparin sodium; taurolidine	SOLUTION;N/A	214520-001	Nov 15, 2023		RX	Yes	Yes	7,696,182		Y	Y		A CATHETER LOCK SOLUTION TO REDUCE CATHETER-RELATED BLOODSTREAM INFECTIONS IN ADULT PATIENTS RECEIVING HEMODIALYSIS THROUGH A CENTRAL VENOUS CATHETER
Cormedix	DEFENCATH	heparin sodium; taurolidine	SOLUTION;N/A	214520-002	Nov 15, 2023		RX	Yes	Yes	7,696,182		Y	Y		A CATHETER LOCK SOLUTION TO REDUCE CATHETER-RELATED BLOODSTREAM INFECTIONS IN ADULT PATIENTS RECEIVING HEMODIALYSIS THROUGH A CENTRAL VENOUS CATHETER

International Family Members for US Patent 7,696,182

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
China	101094679
China	103083353
Germany	202005022124
Denmark	1814562
European Patent Office	1814562
European Patent Office	2742945
Spain	2456946