List of Excipients in Branded Drug EOVIST

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Bayer HealthCare Pharmaceuticals Inc	EOVIST	gadoxetate disodium	50419-320	HYDROCHLORIC ACID	1969-12-31
Bayer HealthCare Pharmaceuticals Inc	EOVIST	gadoxetate disodium	50419-320	SODIUM HYDROXIDE	1969-12-31
Bayer HealthCare Pharmaceuticals Inc	EOVIST	gadoxetate disodium	50419-320	TROMETHAMINE	1969-12-31
Bayer HealthCare Pharmaceuticals Inc	EOVIST	gadoxetate disodium	50419-320	WATER	1969-12-31

Eovist Excipient Strategy and Commercial Opportunities for Gadoxetate Disodium

Last updated: August 5, 2026

Eovist is a low-complexity, injectable gadolinium-based contrast agent whose commercial value is driven primarily by the active ingredient, manufacturing quality, MRI workflow, and supply reliability rather than by proprietary excipient technology. Its core formulation uses gadoxetate disodium in an aqueous solution with trometamol, hydrochloric acid, and water for injection. The strongest opportunities are generic or regional supply, ready-to-use presentation formats, hospital-contract manufacturing, and differentiated packaging or dosing systems.

What is Eovist and which excipients does it contain?

Eovist, known as Primovist outside the United States, contains gadoxetate disodium, also called gadoxetic acid disodium. It is an intravenous hepatobiliary contrast agent used for liver magnetic resonance imaging.

The U.S. product is supplied as a sterile, clear injectable solution containing 0.25 mmol/mL of gadoxetate disodium. The approved formulation includes:

Component	Function
Gadoxetate disodium	Paramagnetic active pharmaceutical ingredient
Tromethamine, also called trometamol	Buffer and pH-control agent
Hydrochloric acid	pH adjustment
Water for injection	Vehicle

The U.S. label identifies gadoxetate disodium at approximately 181.43 mg/mL. The finished product has an acidic-to-neutral controlled pH range and is supplied as a single-use intravenous injection.[1]

The formulation is intentionally conservative. It does not rely on preservatives, surfactants, co-solvents, antioxidants, or complex polymeric excipients. That design reduces injection-site and compatibility risks while simplifying sterile manufacturing.

What is the role of trometamol in Eovist?

Trometamol provides buffering capacity and helps maintain formulation pH during manufacture, storage, and administration. It is a common pharmaceutical excipient with established parenteral use.

For a generic applicant, trometamol is unlikely to create a material composition-of-matter barrier. Its importance is technical rather than patent-driven. Changes in concentration can affect pH, osmolality, chemical stability, container compatibility, and the impurity profile of gadoxetate disodium.

Why does Eovist use hydrochloric acid?

Hydrochloric acid is used for pH adjustment. It is not generally viewed as an independent functional formulation innovation. Its concentration is expected to be controlled through the finished-product specification rather than treated as a fixed quantitative excipient claim.

What excipient strategy is most appropriate for an Eovist generic?

The lowest-risk strategy is to reproduce the reference formulation closely, using the same excipient classes and an equivalent quantitative composition where practical. A compositionally simple formulation supports an abbreviated regulatory pathway and reduces the probability of clinical bridging requirements.

A generic developer should prioritize:

1. Equivalent gadoxetate disodium concentration.
2. Equivalent pH and osmolality.
3. Comparable extractables and leachables profile.
4. Comparable visible and subvisible particulate control.
5. Equivalent container closure integrity.
6. Comparable stability through the labeled shelf life.
7. Compatibility with hospital injectors, syringes, and MRI administration systems.

The principal development risk is not excipient novelty. It is control of the active ingredient and the finished sterile product.

Which excipients should a developer avoid?

Adding an excipient not present in the reference product can increase regulatory and commercial risk. Potentially unnecessary additions include:

• Preservatives, because the product is a single-use injectable.
• Surfactants, unless a demonstrated solubility or aggregation problem exists.
• Antioxidants, unless supported by degradation data.
• Chelating agents, which could interact with the gadolinium complex.
• Additional tonicity agents, if the reference product's osmolality can be matched without them.
• Alternative buffers, which may affect complex stability and equivalence.

A modified formulation may be commercially useful only if it solves a documented problem, such as extended in-use stability, a new administration device, or a lower-volume presentation.

What formulation patents protect Eovist?

The main historical protection for Eovist was associated with the active pharmaceutical ingredient and the original product development rather than a complex excipient platform. Eovist received U.S. Food and Drug Administration approval in 2008 under NDA 022090.[1,2]

The original new chemical entity exclusivity period has expired. The product is also beyond the normal commercial life of the early patent estate. Current commercial barriers are therefore more likely to involve:

• Active-ingredient manufacturing know-how.
• Chiral and coordination chemistry control.
• Residual free gadolinium limits.
• Sterile filling capability.
• Regulatory approval and inspection history.
• Supply contracts with hospitals and imaging networks.
• Product liability and pharmacovigilance performance.

The Orange Book remains the controlling source for current U.S. listed patents and exclusivity. A developer evaluating an abbreviated new drug application should review the live Orange Book record for Eovist and any approved generic entries before selecting a Paragraph IV position.[3]

Does Eovist have method-of-use patent protection?

Method-of-use protection is less likely to be commercially decisive than active-ingredient and regulatory protection. Eovist's use in hepatobiliary MRI is central to its product identity, but a generic applicant can generally seek approval for non-patented uses while carving out protected indications if a relevant listed method-of-use patent remains enforceable.

The main legal issues are:

• Whether any method-of-use patent remains listed for the reference product.
• Whether the proposed label includes the patented liver-imaging indication.
• Whether a Paragraph IV certification is necessary.
• Whether a section viii statement can remove a protected use from the label.
• Whether the innovator can establish induced-infringement liability based on the proposed labeling.

When does Eovist lose exclusivity?

Eovist lost its original regulatory exclusivity years ago. Its commercial exclusivity is now primarily market-based rather than dependent on NCE exclusivity.

Milestone	Eovist status
U.S. approval	2008
Original NCE exclusivity	Expired
Original product patent life	Historical protection largely expired
Current competition	Governed by FDA approvals, supply, contracting, and any live listed patents
Biosimilar pathway	Not applicable
Generic pathway	ANDA pathway may be available, subject to FDA requirements and Orange Book review

The absence of biologic status is important. Eovist is a small-molecule chemical drug, not a biologic. A competitor does not need to develop a biosimilar under the Public Health Service Act. The relevant route is an ANDA or, where equivalence cannot be established through an ANDA, a full or hybrid application.

What is the FDA regulatory status of Eovist?

Eovist is an FDA-approved prescription diagnostic radiopharmaceutical-adjacent contrast product, although it is regulated as a drug rather than as a biologic. Its active ingredient is a gadolinium-based contrast agent with hepatobiliary uptake.

The FDA-approved use is intravenous contrast enhancement during MRI of the liver in adults, including detection and characterization of liver lesions.[1] Pediatric use has also been addressed in labeling and regulatory materials.

The regulatory package for a generic product would focus on:

• Pharmaceutical equivalence.
• Active-ingredient identity and strength.
• Sterility and endotoxin control.
• Elemental and organic impurity controls.
• Gadolinium complexation and free-gadolinium limits.
• Stability and degradation products.
• Container closure integrity.
• Comparative physicochemical performance.
• Labeling and administration compatibility.

The FDA Inactive Ingredient Database can support excipient precedent analysis, but it does not eliminate the need to demonstrate product-specific safety and quality.[4]

How strong is the patent estate for Eovist?

The patent estate is likely weak as a standalone barrier compared with newer specialty drugs. The more durable barriers are technical and operational.

Barrier	Relative significance	Commercial assessment
Original active-ingredient patents	Low	Historical protection has aged
NCE exclusivity	None remaining	Expired
Excipient composition	Low	Simple, conventional excipient system
Manufacturing process	Medium to high	Complex metal-chelate chemistry can be difficult to reproduce
Sterile injectable production	High	Requires qualified facilities and inspection readiness
Clinical positioning	Medium	Hepatobiliary imaging expertise and physician familiarity matter
Hospital contracting	Medium to high	Price and supply reliability influence formulary placement
Safety monitoring	Medium	Gadolinium-related warnings and adverse-event management remain material
Device compatibility	Medium	Injector and vial/syringe integration can differentiate suppliers

The strongest defensible intellectual property for a follow-on product would likely concern a process, impurity-control method, novel container closure, prefilled delivery system, or improved formulation stability. A simple substitution of trometamol concentration or hydrochloric acid quantity would have limited patent value unless linked to a measurable technical advantage.

What commercial opportunities exist for Eovist excipients?

The excipient opportunity is narrow but commercially actionable. It is better understood as a platform for manufacturing and product differentiation than as a conventional excipient-licensing opportunity.

1. Generic finished-product supply

A manufacturer can produce a compositionally similar product using established parenteral excipients. The opportunity is strongest in markets where Eovist pricing is high, supply is concentrated, or hospitals seek a second source.

The commercial case depends on:

• Cost of gadoxetate disodium.
• Yield and batch failure rate.
• Sterile fill-finish costs.
• Vial and packaging costs.
• Regulatory filing fees.
• Distribution and cold-chain requirements.
• Discount demanded by hospital purchasing groups.

2. Contract manufacturing

Specialized sterile manufacturers can offer fill-finish services to active-ingredient suppliers or regional generic companies. Eovist's simple excipient system is suitable for a contract model, provided the facility can handle:

• High-value gadolinium chelates.
• Low particulate specifications.
• Small-volume sterile filling.
• Nitrogen or controlled-atmosphere processes if required by stability data.
• Vial, syringe, or cartridge formats.
• Extractables and leachables testing.

3. Prefilled syringe products

A prefilled syringe could reduce preparation steps in radiology departments and improve dose standardization. The product would need to demonstrate:

• Chemical compatibility between solution and syringe components.
• Low tungsten and silicone-related particulate risk where applicable.
• Closure integrity.
• Needle or connector compatibility.
• Device accuracy across the labeled dose range.
• Stability during shipping and storage.

The prefilled format may support a device or combination-product strategy, although it would not automatically create strong exclusivity.

4. Lower-waste packaging

Eovist is administered in imaging departments where dose preparation and residual drug disposal affect cost. A manufacturer could evaluate smaller presentations, dose-optimized packaging, or ready-to-use formats that reduce unused product.

The economic benefit depends on dosing practice and local procurement rules. Packaging innovation is more likely to create a contracting advantage than a broad patent moat.

5. Regional manufacturing and supply security

Gadolinium contrast shortages have shown that hospitals value dependable supply. A second-source strategy can be commercially attractive even with modest price discounts if it provides:

• Local or regional production.
• Dual-source raw materials.
• Redundant sterile filling.
• Shorter lead times.
• Emergency inventory.
• Regulatory support for hospital tenders.

Which companies are challenging Eovist?

The relevant competitive field includes Bayer, the original Eovist/Primovist sponsor, generic injectable manufacturers, contrast-agent specialists, and hospital-focused sterile suppliers. Competition is not limited to products containing gadoxetate disodium. Radiology departments also compare Eovist with other liver-imaging contrast agents and with extracellular gadolinium products.

Direct competitors may include products based on:

• Gadoxetate disodium.
• Gadobenate dimeglumine.
• Gadobutrol.
• Gadoterate meglumine.
• Gadoteridol.

These products are not clinically interchangeable in every liver-imaging use. Eovist's hepatobiliary uptake gives it a differentiated clinical position, while other agents may compete on price, broader MRI use, supply, or institutional preference.

What Paragraph IV challenges and litigation affect Eovist?

A Paragraph IV challenge would require a generic applicant to certify that a listed patent is invalid, unenforceable, or not infringed. The commercial consequences would depend on the current Orange Book record and the timing of any notice letter.

The typical sequence is:

Stage	Commercial effect
ANDA filing	Establishes potential generic entry
Paragraph IV notice	Triggers patent-litigation risk
Innovator lawsuit within statutory period	May trigger 30-month stay
Settlement or dismissal	Can alter launch timing
FDA approval	Does not necessarily remove patent risk
Commercial launch	May occur at risk if litigation remains unresolved

No biosimilar litigation pathway applies because Eovist is not a biologic. Any settlement agreement would be evaluated for launch date, supply terms, authorized-generic provisions, and antitrust risk.

Publicly disclosed licensing arrangements are not a central part of Eovist's commercial history. The principal strategic value lies in product approval, manufacturing capability, and distribution rather than in a visible excipient license portfolio.

How does Eovist compare with other liver MRI contrast agents?

Product type	Hepatobiliary uptake	Excipient complexity	Main competitive strength
Eovist, gadoxetate disodium	Yes	Low	Strong liver-specific imaging profile
Gadobenate-based agents	Partial or delayed uptake	Low to moderate	Broad MRI use with some hepatobiliary utility
Extracellular agents	No meaningful hepatobiliary uptake	Low	Broad availability and often lower cost
Macrocyclic agents	Primarily extracellular	Low	Stability profile and institutional familiarity

Eovist's commercial differentiation is clinical rather than excipient-based. A follow-on product should preserve the hepatobiliary imaging performance and match administration characteristics. A cheaper product with altered pH, osmolality, viscosity, or injector compatibility could lose adoption even if it satisfies formal pharmaceutical equivalence.

What generic launch risks exist for Eovist?

The principal launch risks are:

• Difficulty reproducing gadoxetate disodium quality attributes.
• Failure to control free gadolinium or metal-related impurities.
• Sterility or particulate failures.
• Incomplete compatibility data for MRI injectors.
• Hospital reluctance to switch contrast products.
• Supply interruptions during launch.
• Regulatory questions about formulation differences.
• Patent or regulatory exclusivity identified in the current Orange Book.
• Low market size relative to development and validation costs.

Revenue exposure for the innovator is concentrated in hepatobiliary MRI use. Generic entry would likely produce price erosion, but the pace would depend on the number of approved suppliers and the strength of hospital contracting. The product's specialized indication may limit automatic substitution compared with high-volume, multisource injectable drugs.

What geographic opportunities exist for Eovist competitors?

The commercial opportunity is strongest in jurisdictions with:

• Established MRI utilization.
• High use of contrast-enhanced liver imaging.
• Centralized hospital procurement.
• Limited local supply of gadoxetate products.
• Reimbursement that recognizes liver-specific imaging value.
• Regulatory pathways for abbreviated chemical-drug applications.

The United States offers an ANDA-based opportunity if the reference-product and Orange Book requirements are satisfied. Europe and other regulated markets may offer decentralized or national opportunities through generic or hybrid applications, but naming, device, pack-size, and pharmacovigilance requirements differ. Emerging markets may present a larger price-sensitive opportunity, but local registration, tender qualification, and supply reliability often determine success.

Key Takeaways

• Eovist contains a simple injectable excipient system: trometamol, hydrochloric acid, and water for injection.
• The active ingredient is gadoxetate disodium at approximately 0.25 mmol/mL.
• Excipient innovation is unlikely to create substantial value unless it improves stability, packaging, administration, or waste reduction.
• The original regulatory and patent exclusivity has expired or is no longer the main commercial barrier.
• Generic opportunities depend more on active-ingredient manufacturing, sterile filling, quality control, and hospital contracting.
• Eovist is a small-molecule drug, so biosimilar risk is not applicable.
• Prefilled syringes, regional supply, dual-source manufacturing, and dose-optimized packaging offer the clearest commercial opportunities.
• A current Orange Book review is necessary before relying on a Paragraph IV or section viii strategy.
• Eovist competes clinically with other liver MRI contrast agents, but its hepatobiliary uptake remains its main product differentiator.

FAQs

Is trometamol in Eovist patent-protected?

Trometamol is a conventional parenteral buffer and is not, by itself, a meaningful exclusivity barrier for Eovist. Its concentration, pH impact, and compatibility with gadoxetate disodium must still be controlled in a generic product.

Can Eovist be reformulated without hydrochloric acid?

A reformulation may be technically possible if another approved pH-adjustment approach produces equivalent quality and stability. The regulatory burden would increase because the applicant would need to justify the change and establish comparability.

Is there a preservative-free commercial opportunity for Eovist?

Yes, but the reference product already uses a single-use injectable design without a conventional preservative. The opportunity is therefore in packaging, dosing, and supply rather than in removing preservatives.

Could an Eovist competitor use a different buffer?

A different buffer could be used only with adequate evidence that it does not alter chelate stability, pH, osmolality, impurity formation, injection compatibility, or clinical performance. A reference-matched buffer is the lower-risk strategy.

Does Eovist require a biosimilar application?

No. Gadoxetate disodium is a chemically synthesized small-molecule drug. A competing product would generally pursue an ANDA or another applicable drug-approval pathway, not a biosimilar application.

References

1. U.S. Food and Drug Administration. (2023). Eovist (gadoxetate disodium) injection: Prescribing information. Bayer HealthCare Pharmaceuticals Inc.

2. U.S. Food and Drug Administration. (2008). Drugs@FDA: Eovist, NDA 022090. Center for Drug Evaluation and Research.

3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. Center for Drug Evaluation and Research.

4. U.S. Food and Drug Administration. (2024). Inactive Ingredient Database. Center for Drug Evaluation and Research.

5. European Medicines Agency. (2024). Primovist: Summary of product characteristics. Bayer AG.