List of Excipients in Branded Drug CORVERT

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Pharmacia & Upjohn Company LLC	CORVERT	ibutilide fumarate	0009-3794	HYDROCHLORIC ACID
Pharmacia & Upjohn Company LLC	CORVERT	ibutilide fumarate	0009-3794	SODIUM ACETATE
Pharmacia & Upjohn Company LLC	CORVERT	ibutilide fumarate	0009-3794	SODIUM CHLORIDE
Pharmacia & Upjohn Company LLC	CORVERT	ibutilide fumarate	0009-3794	WATER

Corvert Excipient Strategy and Commercial Opportunities for Ibutilide Fumarate Injection

Last updated: August 13, 2026

Corvert is the original brand for ibutilide fumarate injection, an intravenous class III antiarrhythmic used for rapid conversion of atrial fibrillation and atrial flutter. Its formulation is commercially simple: a low-concentration, preservative-free, isotonic aqueous solution supplied in a single-use vial. The principal commercial opportunity is not formulation differentiation through complex excipients. It is reliable hospital supply, ready-to-administer presentation, regulatory substitution, and improved workflow around a narrowly used emergency cardiovascular product.

What is Corvert and how is ibutilide supplied?

Corvert contains ibutilide fumarate, equivalent to 0.1 mg/mL of ibutilide. The labeled presentation is a 10 mL single-use vial containing 1 mg of ibutilide equivalent. The product is administered intravenously under continuous ECG monitoring because ibutilide can prolong the QT interval and cause torsades de pointes. Patients require electrolyte correction and post-dose observation under the prescribing information.[1]

Attribute	Corvert formulation
Active ingredient	Ibutilide fumarate
Strength	0.1 mg/mL ibutilide equivalent
Dose presentation	10 mL vial, 1 mg ibutilide equivalent
Route	Intravenous infusion
Dosage form	Sterile aqueous injection
Preservative	None identified in the U.S. product labeling
Tonicity approach	Sodium chloride-containing isotonic vehicle
Primary use	Pharmacologic conversion of atrial fibrillation or atrial flutter
Administration setting	Hospital, emergency department, intensive monitoring environment
Principal safety issue	QT prolongation and ventricular arrhythmia risk

The formulation does not require a lipid vehicle, cosolvent system, surfactant, or complex controlled-release technology. The low dose and salt form permit a straightforward aqueous product.

What excipients are used in Corvert?

The principal excipients are sodium chloride and water for injection. The label identifies sodium chloride at approximately 9 mg/mL, consistent with an isotonic saline vehicle. Hydrochloric acid and sodium hydroxide may be used for pH adjustment during manufacture. The product is supplied as a sterile, preservative-free solution.[1,2]

Excipient or component	Function	Commercial significance
Sodium chloride	Tonicity adjustment	Supports intravenous tolerability and a familiar saline composition
Water for injection	Solvent	Standard parenteral vehicle
Hydrochloric acid or sodium hydroxide	pH adjustment	Supports chemical stability and target pH control
Container closure system	Sterility and product protection	Important for extractables, leachables, particulate control, and shelf life

The excipient profile is strategically favorable for a generic manufacturer. A simple formulation reduces development variables, limits raw-material complexity, and lowers the risk that an excipient change will affect injectability or regulatory comparability.

How should a generic manufacturer approach the Corvert formulation?

A generic ibutilide fumarate injection should generally target a composition close to the reference product rather than pursue unnecessary reformulation. The highest-value development objectives are chemical stability, sterility assurance, particulate control, container compatibility, and dose-delivery accuracy.

Recommended excipient strategy

A commercially efficient formulation strategy has five elements:

1. Use the same active salt and concentration.
   Ibutilide fumarate should be controlled against the labeled ibutilide-equivalent strength of 0.1 mg/mL.

2. Retain a simple aqueous vehicle.
   Sodium chloride and water for injection are sufficient for the established product concept. Adding surfactants, polyols, buffers, or organic cosolvents would create new regulatory and compatibility risks without an obvious clinical benefit.

3. Control pH within a validated range.
   pH affects chemical stability, precipitation risk, container interaction, and injection tolerability. The manufacturer should establish a tight process target rather than rely on broad pharmacopeial acceptance limits.

4. Use a preservative-free single-dose configuration.
   The clinical setting, low dose volume, and sterile intravenous route favor a single-use vial. Multidose packaging would introduce preservative and repeated-entry complications.

5. Optimize the container closure.
   A Type I glass vial with a compatible elastomeric stopper is the conventional starting point. The supplier qualification package should cover tungsten, glass delamination, stopper extractables, particles, and adsorption.

Why complex excipients are unlikely to create value

Corvert’s active concentration is low, and the marketed product already demonstrates that the drug can be delivered in a simple aqueous system. A new solubilization platform would need to improve a measurable commercial attribute, such as shelf life, cold-chain avoidance, administration time, or compatibility with premixed infusion systems. Without that improvement, the added excipient burden would increase development cost and FDA review risk.

What formulation patents protect Corvert?

No current formulation patent barrier is apparent from the basic Corvert product concept and its publicly available U.S. labeling. The original product was approved in 1995, so its five-year new chemical entity exclusivity would have expired in 2000. Any original composition-of-matter or formulation patent protection would ordinarily have expired well before the current generic opportunity.[1,3]

The commercially relevant protection is therefore unlikely to be an active Corvert formulation patent. Risk is more likely to arise from:

• manufacturing process patents not listed in the Orange Book;
• proprietary sterile-filling processes;
• container-closure configurations;
• unpublished supplier arrangements;
• hospital contracting and shortage-driven purchasing;
• regulatory exclusivity associated with a future improved product.

A generic applicant should review the current FDA Orange Book entry for the relevant ibutilide fumarate injection NDA before filing. Orange Book listing status can change independently of the clinical value of the product.[3]

When did Corvert lose exclusivity?

Corvert was approved by the FDA in 1995. The standard five-year NCE exclusivity period associated with an original new chemical entity would have ended in 2000, absent a separate pediatric extension or other statutory extension. The product is now a mature, off-patent injectable opportunity rather than a protected branded asset.[1,3]

Milestone	Timing
FDA approval of Corvert	1995
Expected end of five-year NCE exclusivity	2000
Current opportunity type	Generic or authorized-equivalent injectable
Main commercial barrier	Small market, hospital purchasing, sterile manufacturing
Patent-driven launch restriction	No material current restriction apparent from the basic product record

What is the FDA regulatory status of Corvert?

Corvert is an FDA-approved product for conversion of atrial fibrillation and atrial flutter. The product requires administration in a monitored setting. The label emphasizes ECG monitoring before and after administration, correction of potassium and magnesium abnormalities, and readiness to manage ventricular arrhythmias.[1]

The commercial status of the brand should be distinguished from the regulatory status of the active ingredient. A brand may be discontinued from marketing while the NDA remains listed in FDA databases as approved, discontinued, or otherwise subject to administrative status changes. FDA records and the current Orange Book entry should control any filing, acquisition, or licensing decision.[3,4]

There is no biosimilar pathway for ibutilide. It is a chemically synthesized small molecule, so the relevant competitive pathway is an ANDA under section 505(j), not a 351(k) biosimilar application.

What Paragraph IV challenges and patent litigation affect Corvert?

The principal historical exclusivity period ended decades ago. A modern ibutilide fumarate ANDA would not ordinarily face the same patent barriers associated with newer cardiovascular products. No major, current Corvert patent-litigation event is apparent from the mature product profile.

A Paragraph IV certification would become relevant only if the applicable Orange Book listing contained an unexpired patent. For a 1995 injectable product, the more likely filing posture is a paragraph III certification if an identified patent has not expired, or a paragraph IV certification if the applicant contests the patent’s validity, enforceability, or infringement. The business case should not assume that a Paragraph IV litigation strategy is available without a live review of the Orange Book listing.

The likely launch risk is commercial rather than litigation-driven:

• limited annual demand;
• hospital formulary substitution;
• incumbent generic supply;
• sterile injectable manufacturing capacity;
• low-volume inventory economics;
• purchasing pressure from group purchasing organizations.

What commercial opportunities exist for Corvert excipients and dosage forms?

The strongest opportunities fall into four product formats.

1. Standard single-dose vial

This is the lowest-risk path and the closest competitive substitute for Corvert. A manufacturer can target hospital pharmacies that already use vial-based preparation. The formulation can remain preservative-free and saline-based.

Commercial advantage: low development complexity and broad compatibility with existing protocols.

2. Ready-to-use prefilled syringe

A prefilled syringe could reduce dose preparation and handling in emergency settings. The product would need validated syringe materials, low adsorption, accurate delivery of the small dose, and robust stability data.

Commercial advantage: fewer preparation steps and lower pharmacy workload.

Risk: a new container system may require extensive compatibility and human-factors work. The market may not support the added packaging cost unless hospitals identify a meaningful workflow benefit.

3. Pharmacy-ready infusion bag

A premixed bag could eliminate dilution errors and shorten preparation time. It would require a concentration and volume that fit existing administration protocols, as well as stability data in the selected bag film.

Commercial advantage: improved standardization and reduced manipulation.

Risk: the product may have low turnover, creating expiration and inventory losses. A bag format also increases shipping volume and manufacturing cost.

4. Dual-strength or dose-optimized presentation

The label uses weight-based dosing, with a standard initial dose of 1 mg for patients weighing at least 60 kg and 0.01 mg/kg for patients below 60 kg. A second strength could simplify pediatric or low-weight dosing, but the small patient population may not justify separate manufacturing and inventory.[1]

Commercial advantage: reduced calculation and withdrawal errors.

Risk: additional SKUs, labeling complexity, and limited demand.

How strong is the excipient and manufacturing IP opportunity?

The formulation patent position is weak as a standalone investment thesis. The product’s value lies in execution rather than proprietary excipient technology.

IP or operational layer	Relative opportunity
New excipient composition	Low
Simple generic aqueous injection	Moderate
Premixed infusion presentation	Moderate
Prefilled syringe	Moderate, with higher development cost
Sterile manufacturing know-how	High operational relevance
Container-closure optimization	Moderate
Supply reliability and shortage response	High commercial relevance
Method-of-use patenting	Low for the established indication
New indication patenting	Potentially material but clinically uncertain

A company could seek protection for a genuinely improved formulation, such as a stable premix with an extended shelf life or a ready-to-use delivery system. Such protection would need to cover a real technical improvement rather than merely restating the known saline formulation.

What generic entry risks exist for ibutilide fumarate injection?

Generic entry is technically feasible but commercially narrow. The principal risks are:

1. Sterile injectable manufacturing failure.
   A single particulate, sterility, endotoxin, or container-closure problem can interrupt supply and trigger regulatory action.

2. Low-volume economics.
   Demand may be insufficient to support multiple suppliers, especially if hospitals purchase the product only for intermittent use.

3. Clinical monitoring requirements.
   Because ibutilide carries a torsades risk, hospitals may favor suppliers with dependable labeling, packaging, and supply continuity.

4. Substitution by electrical cardioversion or other antiarrhythmics.
   Ibutilide competes with procedural cardioversion and alternative pharmacologic strategies. Its market is therefore constrained by clinical practice, not only by generic price.

5. Inventory expiration.
   Hospitals and distributors may hold limited stock, making shelf life and minimum order quantities important purchasing variables.

6. Regulatory documentation.
   The applicant must demonstrate pharmaceutical equivalence and bioequivalence or otherwise satisfy the applicable injectable-product requirements. The simplicity of the excipient system does not eliminate the need for robust sterility and stability programs.[4]

How does Corvert compare with competing antiarrhythmic products?

Corvert has a different commercial profile from oral amiodarone, sotalol, and dofetilide. It is an acute intravenous conversion product rather than a chronic maintenance therapy.

Product	Route	Primary commercial role	Excipient opportunity
Ibutilide fumarate	IV	Rapid pharmacologic conversion	Vial, syringe, or premix
Amiodarone	IV and oral	Acute management and chronic rhythm control	Complex IV excipient and infusion compatibility
Dofetilide	Oral	Rhythm maintenance	Capsule manufacturing, not injectable excipients
Sotalol	Oral and IV in selected markets	Rate/rhythm management	Oral and injectable platform opportunities
Electrical cardioversion	Procedure	Rapid rhythm conversion	No drug-product opportunity

Ibutilide’s advantage is speed in selected patients. Its limitation is the requirement for cardiac monitoring and the risk of QT-mediated ventricular arrhythmia. This makes the product more valuable as a dependable hospital tool than as a broad outpatient franchise.

What licensing and acquisition opportunities exist?

A licensing transaction would be most defensible around a complete product package rather than an excipient alone. Attractive assets could include:

• an approved or near-approval ANDA;
• a ready-to-use ibutilide presentation;
• an established sterile injectable manufacturing slot;
• a validated long-shelf-life formulation;
• hospital contracts or distributor access;
• rights in markets where no reliable supplier exists.

There is limited rationale for licensing basic sodium chloride and water-for-injection know-how. The value would come from regulatory status, manufacturing capacity, packaging differentiation, and commercial access.

Revenue exposure should be modeled as a niche hospital product. Public company filings may not report ibutilide revenue separately. A buyer should therefore value the product through unit demand, net price, manufacturing cost, wastage, wholesaler deductions, and hospital contract retention rather than headline cardiovascular-market size.

What geographic markets are most attractive?

The United States is the clearest regulatory reference market because Corvert has an FDA approval history and an Orange Book framework. Other opportunities depend on local registration, pharmacopoeial requirements, and hospital procurement.

Potentially attractive regions have three characteristics:

• established use of pharmacologic cardioversion;
• limited local sterile-injectable competition;
• hospital systems that reward ready-to-use presentations.

A global strategy should not assume that U.S. labeling, excipient specifications, or packaging approvals transfer automatically. European and other jurisdictions may require separate regulatory filings, local pharmacopoeial compliance, and different container-closure documentation.

Key Takeaways

• Corvert is ibutilide fumarate injection, a mature intravenous antiarrhythmic product approved in 1995.
• The formulation uses a simple, preservative-free aqueous vehicle centered on sodium chloride and water for injection.
• The strongest generic strategy is formulation replication with strict control of pH, sterility, particulates, stability, and container compatibility.
• There is no material current patent barrier apparent from the mature Corvert product profile; FDA Orange Book status should govern filing decisions.
• Ibutilide has no biosimilar pathway. Competition proceeds through small-molecule generic regulation.
• Commercial value is concentrated in hospital supply reliability, ready-to-use packaging, sterile manufacturing capacity, and inventory management.
• Prefilled syringes and premixed infusion bags offer the clearest product-differentiation opportunities, but their economics depend on low-volume hospital demand.
• Excipient innovation alone is unlikely to support a strong licensing thesis unless it produces a measurable stability, workflow, or administration benefit.

FAQs

Is Corvert still a protected brand drug?

No material active exclusivity barrier is apparent from the original 1995 approval history. The original five-year NCE exclusivity period would have ended in 2000.

Can ibutilide fumarate be developed as a biosimilar?

No. Ibutilide fumarate is a small-molecule drug. The applicable U.S. pathway is generally an ANDA, not a biosimilar application.

Does Corvert require a preservative?

The labeled injectable product is preservative-free. A single-use vial is consistent with the product’s sterile intravenous administration.

Could a manufacturer patent a premixed ibutilide infusion bag?

Potentially, if the product has a novel and non-obvious formulation, container system, stability profile, or manufacturing process. A basic saline premix would face a weaker patent position than a formulation with a demonstrated technical improvement.

What is the main investment risk in an ibutilide generic?

The main risk is limited and unpredictable hospital demand combined with sterile injectable manufacturing costs. Patent litigation is less likely to be the primary barrier than supply economics, inventory loss, and competition from established generic suppliers.

References

1. U.S. Food and Drug Administration. (1995). Corvert (ibutilide fumarate) injection prescribing information.
2. National Library of Medicine. (n.d.). DailyMed: Ibutilide fumarate injection. U.S. National Library of Medicine.
3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book.
4. U.S. Food and Drug Administration. (2013). ANDAs for certain highly purified synthetic peptide drug products that refer to listed drugs of recombinant origin: Guidance for industry.