List of Excipients in Branded Drug FLUMAZENIL

Generic Drugs Containing FLUMAZENIL

Company	Ingredient	NDC	Excipient
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	ACETIC ACID
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	EDETATE DISODIUM
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	HYDROCHLORIC ACID
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	METHYLPARABEN
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	PROPYLPARABEN
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	SODIUM CHLORIDE
Hikma Pharmaceuticals USA Inc	flumazenil	0143-9683	SODIUM HYDROXIDE

What are the Most Frequently-Used Excipients in FLUMAZENIL?

# Of NDCs	Excipient
30	ACETIC ACID
29	EDETATE DISODIUM
1	EDETATE SODIUM
30	HYDROCHLORIC ACID
30	METHYLPARABEN
30	PROPYLPARABEN
30	SODIUM CHLORIDE

Flumazenil Excipient Strategy and Commercial Opportunities

Last updated: August 4, 2026

Flumazenil is an established benzodiazepine antagonist with limited differentiation at the active-ingredient level. Commercial opportunity is concentrated in formulation engineering, emergency-use convenience, product reliability, pediatric dosing, and hospital supply-chain performance rather than in new chemical-entity protection. The highest-value product concepts are ready-to-administer injectable presentations, stable low-volume dosing systems, and alternative delivery routes that can obtain regulatory differentiation through a 505(b)(2) pathway.

What is the FDA status of flumazenil?

Flumazenil is an FDA-approved benzodiazepine receptor antagonist used to reverse the sedative effects of benzodiazepines after anesthesia and to manage suspected benzodiazepine overdose. The reference product is Romazicon, originally approved by the FDA in 1991 under NDA 019430. Generic flumazenil injection products are approved under abbreviated new drug applications.

Attribute	Current commercial profile
Active ingredient	Flumazenil
Pharmacologic class	Benzodiazepine receptor antagonist
Primary route	Intravenous injection
Common concentration	0.1 mg/mL
Primary users	Hospitals, emergency departments, ambulatory surgery centers, anesthesiology services
FDA pathway for standard generic	ANDA under Section 505(j)
FDA pathway for new route or delivery system	Potentially 505(b)(2)
Biosimilar exposure	None; flumazenil is a chemically synthesized small molecule
Reference product	Romazicon
Commercial setting	Institutional, emergency, low-frequency but high-urgency use

The product is administered intravenously because rapid reversal is clinically important. The labeled indication does not make flumazenil a general treatment for all altered mental-status events. Seizure risk, resedation, mixed-drug overdose, and chronic benzodiazepine dependence constrain use and affect product positioning. [1]

What excipients are used in flumazenil injection?

The standard flumazenil injection formulation uses a simple aqueous system. The Romazicon label identifies edetate disodium, glacial acetic acid, sodium chloride, sodium hydroxide, and water for injection as inactive ingredients. The formulation is acidic, with a labeled pH range of approximately 3.7 to 5.2. [1]

Excipient	Functional role	Commercial relevance
Edetate disodium	Chelating agent	Controls trace-metal effects that can accelerate degradation
Glacial acetic acid	Acidifying agent and buffer component	Establishes the acidic formulation environment
Sodium hydroxide	pH adjustment	Controls final pH and product consistency
Sodium chloride	Tonicity adjustment	Supports intravenous tolerability
Water for injection	Vehicle	Enables parenteral administration

The excipient system is conservative and compatible with an emergency injectable. It avoids unnecessary surfactants, preservatives, and complex solubilization technologies. That simplicity reduces formulation risk but leaves room for differentiated packaging and delivery.

How does the flumazenil formulation create commercial opportunities?

The primary opportunity is to improve administration rather than to change the pharmacology. Hospitals value products that reduce preparation steps, dosing errors, waste, and delays during airway or sedation emergencies.

Ready-to-administer syringes

A prefilled syringe could compete on workflow efficiency. The commercial proposition would include:

• No vial transfer or syringe preparation.
• Lower risk of needlestick exposure.
• Faster administration in emergency departments and procedural areas.
• Reduced drug waste from partially used vials.
• Standardized dose labeling.
• Better compatibility with automated medication cabinets.

A prefilled syringe would need robust extractables and leachables data, container-closure integrity, syringe-device compatibility, and stability through shipping and storage. The acidic formulation may affect elastomer components, lubricants, needle adhesives, and syringe barrels. Device selection is therefore a material-science issue, not only a packaging decision.

Unit-dose ampoules and low-waste presentations

Small-volume unit doses can improve use in anesthesia and emergency medicine. The product must balance dose flexibility against inventory complexity. A 0.1 mg/mL solution requires careful calculation because clinical doses may be titrated in increments smaller than the full vial or syringe content.

A commercial portfolio could include:

Presentation	Target setting	Main advantage
Single-dose vial	General hospital stock	Lowest manufacturing complexity
Glass ampoule	Emergency and anesthesia carts	Compact, familiar packaging
Prefilled syringe	Emergency department and procedural care	Faster administration
Dual-pack or kit	Overdose response and sedation reversal	Combines flumazenil with workflow materials
Low-volume syringe	Pediatric or titrated dosing	Reduces waste and improves dose control

Kit products require careful regulatory analysis. A kit containing only the drug and administration accessories may remain within a conventional drug-device combination strategy. A kit containing diagnostic components, rescue medicines, or clinical decision tools may trigger additional regulatory and reimbursement complexity.

Preservative-free positioning

An injectable flumazenil product can be positioned as preservative-free if the selected container, manufacturing process, and stability package support that claim. The reference formulation does not rely on a conventional antimicrobial preservative. A preservative-free claim is commercially relevant for single-dose emergency use and for institutional procurement standards.

The claim should not be treated as a major clinical differentiator by itself. Its value is operational: it simplifies use in sensitive populations and aligns with single-dose parenteral practice.

Stability and cold-chain reduction

Improved stability could create a meaningful hospital value proposition. A formulation that maintains specification across a broader temperature range could reduce product loss during ambulance transport, emergency-cart storage, and disaster response.

Potential development approaches include:

• Optimizing pH within the clinically acceptable range.
• Tightening control of trace metals and oxygen exposure.
• Evaluating nitrogen headspace or low-oxygen filling.
• Screening container materials for adsorption and leachables.
• Assessing light-protective packaging.
• Comparing standard glass, polymer vials, and cyclic olefin polymer systems.
• Establishing in-use stability after vial entry or syringe activation.

A stability claim must be supported by real-time and accelerated data under the final container-closure configuration. It cannot be inferred from the active ingredient or from an unrelated benzodiazepine product.

What formulation patents protect flumazenil?

The original flumazenil product and core injectable formulation are mature technologies. The principal commercial barrier is regulatory execution and supply reliability, not a prominent active patent estate.

Core product and composition protection

The original composition, manufacturing, and use patents associated with flumazenil are generally old relative to the drug’s 1991 FDA approval. Standard flumazenil injection is therefore exposed to generic competition. Any current patent position would need to be confirmed against the FDA Orange Book, relevant national registers, and the specific product’s labeling.

For a conventional 0.1 mg/mL injectable using broadly known excipients, new patent claims would face a high obviousness risk. A defensible patent strategy would focus on a technical result, such as:

• Unexpected stability under defined conditions.
• A specific container-closure combination.
• Reduced adsorption or degradation.
• A novel ready-to-administer device.
• A new nonintravenous delivery route.
• A defined pediatric dosing system.
• A manufacturing process that materially improves purity or shelf life.

A patent covering only the use of standard sodium chloride, acetate, edetate, and water in a conventional flumazenil injection would likely provide limited commercial strength unless supported by unexpected performance data.

Method-of-use patents

Potential method-of-use claims could address benzodiazepine reversal in defined clinical populations or dosing protocols. However, many core uses are already established. Narrow claims may be possible for selected patient groups, titration regimens, or administration systems, but enforceability and freedom-to-operate value would depend on claim scope and clinical adoption.

Method-of-use protection is more commercially credible when paired with a product that makes the claimed protocol easier to execute, such as a calibrated syringe or a low-dose pediatric presentation.

When does flumazenil lose exclusivity?

Flumazenil’s core U.S. market exclusivity expired long ago. The reference product’s regulatory exclusivity period has also expired, allowing ANDA competition. The commercial question is therefore not when the molecule loses exclusivity, but whether a new presentation can obtain independent regulatory or patent protection.

Exclusivity category	Flumazenil position
New chemical entity exclusivity	Expired
Core composition patents	Generally expired or commercially exhausted
Standard injectable generic pathway	Available
Biosimilar exclusivity	Not applicable
New formulation patent	Possible if technically novel and non-obvious
New route 505(b)(2) exclusivity	Potentially available if statutory requirements are met
Pediatric exclusivity	Product- and study-specific; no general current assumption
Orphan-drug exclusivity	Not the general basis of the established flumazenil market

The 505(b)(2) route could be relevant for intranasal, buccal, autoinjector, or other delivery systems that rely partly on existing flumazenil data while requiring new clinical, pharmacokinetic, device, or usability evidence. Any exclusivity would attach to the qualifying new product, not to flumazenil as a molecule.

What alternative delivery systems could compete with injectable flumazenil?

Intranasal flumazenil

Intranasal delivery is the clearest product-concept opportunity because it could avoid venous access. Potential target settings include emergency medical services, outpatient procedural facilities, and situations where IV access is delayed.

The main technical challenges are substantial:

• Flumazenil dose delivery through the nasal mucosa.
• Adequate bioavailability and rapid onset.
• Nasal irritation.
• Variability from congestion, bleeding, or secretions.
• Need for repeated doses.
• Device reliability during emergency use.
• Clinical management of resedation after an apparently successful response.

Intranasal flumazenil would likely need a new clinical and device-development package. It would not be a routine ANDA substitution for an intravenous injection.

Buccal or sublingual systems

Buccal and sublingual products could provide systemic delivery without IV access. Flumazenil’s low dose is favorable for compact dosage forms, but taste, mucosal absorption, onset time, and dose uniformity would determine feasibility.

These systems may be more suitable for controlled reversal or supervised procedural settings than for severe overdose cases requiring immediate titration.

Autoinjectors

An autoinjector could improve field deployment, but the product must deliver a precise small volume. Low-volume delivery creates engineering challenges involving dead volume, needle penetration, dose accuracy, and accidental activation.

An autoinjector could be positioned for emergency kits, but institutional protocols would need to address airway management, seizure risk, and repeat dosing. The device would need human-factors validation under stressful conditions.

Oral dosage forms

An oral flumazenil product is commercially less attractive for rapid reversal because onset and absorption may not match emergency requirements. Oral delivery could have investigational value in controlled settings, but it would not directly replace injectable rescue therapy.

What manufacturing and excipient barriers affect flumazenil products?

The manufacturing process is relatively straightforward compared with biologics, liposomal products, or complex depot injections. The main barriers are quality control and sterile supply execution.

Key manufacturing risks include:

1. Sterile fill-finish capacity and validated aseptic processing.
2. Control of particulate matter in a low-volume injectable.
3. Container-closure compatibility with acidic solution.
4. Stability after terminal processing, if terminal sterilization is considered.
5. Assay and impurity control over shelf life.
6. Consistent pH and osmolality.
7. Prevention of adsorption to delivery-device components.
8. Reliable supply of approved pharmaceutical-grade excipients.

Edetate disodium is used at low concentration, but its chelating function makes raw-material quality and trace-metal control relevant. Acetic acid and sodium hydroxide are common excipients, so they are unlikely to create a durable supply barrier. The stronger manufacturing differentiator is validated sterile packaging at commercial scale.

What is the Orange Book and Paragraph IV status of flumazenil?

Flumazenil is a genericized small molecule, not a biosimilar product. Standard ANDA applicants may face ordinary patent-certification requirements, but the historic product’s core exclusivity does not block generic entry.

A Paragraph IV filing would be commercially relevant only if an applicant challenged a listed, unexpired patent associated with a specific reference product or later formulation. For a conventional flumazenil injection, the main competitive risks are more likely to involve:

• Product approval timing.
• Manufacturing-site readiness.
• Drug-shortage conditions.
• Hospital contracting.
• Wholesaler access.
• Device differentiation.
• State and institutional formulary adoption.

The Orange Book should be reviewed at the specific product and patent-listing level before launch or litigation decisions. Patent listings can differ by product, and an absence of a meaningful core patent barrier does not eliminate regulatory or commercial execution risk. [2]

Which companies are competing in flumazenil?

Competition has historically included the reference-product sponsor and multiple generic injectable manufacturers, including large hospital-supply companies and injectable specialists. The competitive field is characterized by low brand loyalty and institutional purchasing.

Competitor type	Product strategy	Competitive strength
Reference-product sponsor	Branded injectable	Historical clinical recognition
Large generic manufacturer	Standard vial or ampoule	Scale and contracting
Injectable specialist	Sterile presentation and supply reliability	Hospital-channel expertise
Device-focused entrant	Prefilled syringe or autoinjector	Workflow differentiation
Specialty 505(b)(2) sponsor	Intranasal or other novel route	Potential exclusivity and new channel access

A new entrant is more likely to win through dependable supply, a differentiated presentation, or a new route than through price alone.

What licensing deals could support a flumazenil product?

Licensing opportunities are most relevant to delivery technology and sterile manufacturing. A sponsor could license:

• Intranasal spray platforms.
• Prefilled syringe systems.
• Autoinjector technology.
• Low-volume drug-delivery devices.
• Sterile fill-finish capacity.
• Regional hospital distribution rights.
• Emergency-medicine commercial infrastructure.

A conventional flumazenil injection has limited standalone licensing value unless the product includes a differentiated device, an approved market position, or manufacturing capacity in a constrained region. The strongest transaction structure would likely combine formulation or device intellectual property with regulatory development rights and commercial supply.

How strong is the flumazenil patent estate?

The core flumazenil patent estate is weak for blocking purposes because the molecule and standard injection are mature. A new product can still create a stronger, narrower estate around delivery, packaging, stability, or clinical use.

Patent category	Expected strategic strength
Core flumazenil composition	Low
Conventional aqueous injection	Low
Standard excipient combination	Low to moderate
Specific stability-enhancing formulation	Moderate if supported by data
Prefilled syringe and container system	Moderate
Intranasal delivery system	Moderate to high if clinically differentiated
Autoinjector configuration	Moderate, subject to device prior art
Narrow dosing method	Variable
Manufacturing process	Moderate if difficult to design around

Patent strength will depend on claim breadth, reproducibility of the claimed benefit, freedom to operate around device components, and whether competitors can use the same active ingredient in a different presentation.

What are the generic launch scenarios for flumazenil?

Scenario 1: Standard injectable entry

This is the lowest-risk pathway. The product competes on price, supply continuity, vial configuration, and hospital contracting. Margins are likely to be pressured by multiple suppliers.

Scenario 2: Ready-to-use injectable

A prefilled syringe can command a premium if it reduces labor, preparation time, and waste. The product must demonstrate reliable shelf life and device performance. The commercial target is hospitals that value emergency workflow and medication safety.

Scenario 3: New-route 505(b)(2) product

An intranasal or autoinjector product could expand use outside IV-equipped facilities. Development costs and clinical requirements are higher, but the product may obtain differentiated labeling, device protection, and potentially regulatory exclusivity.

Scenario 4: Supply-constrained market entry

A manufacturer with reliable sterile capacity can capture share during shortages or supplier withdrawals. This strategy depends on FDA manufacturing compliance, inventory depth, and rapid institutional onboarding.

How does flumazenil compare with naloxone?

Naloxone has a larger public-health market, broader community distribution, and stronger commercial momentum because opioid overdose treatment has expanded beyond hospitals. Flumazenil remains more specialized and is used mainly in supervised clinical settings.

Factor	Flumazenil	Naloxone
Reversal target	Benzodiazepines	Opioids
Dominant setting	Hospital and procedural care	Hospital, EMS, community
IV use	Common	Common but not required
Intranasal opportunity	Significant but clinically complex	Established
Public distribution	Limited	Broad
Safety considerations	Seizure and withdrawal risk	Acute withdrawal and renarcotization
Commercial scale	Smaller	Larger
Main differentiation	Workflow and route	Access, speed, device, distribution

The naloxone market provides a useful development benchmark for emergency delivery systems, but its larger market size should not be assumed for flumazenil.

What is the revenue exposure of a flumazenil product?

Flumazenil is unlikely to support a large branded market through conventional injectable sales alone. Revenue depends on channel selection:

• Standard generic injection: volume-driven, price-sensitive.
• Prefilled syringe: lower volume but potentially higher unit economics.
• Intranasal product: broader addressable setting and greater development cost.
• Specialty hospital kit: premium workflow positioning but limited unit volume.
• Regional supply contract: predictable institutional revenue with procurement pressure.

A commercial model should separate annual unit demand from emergency-stock requirements. Hospitals may hold inventory that is used infrequently but must remain available. That creates a market where supply reliability and expiration management can matter as much as prescription volume.

Key Takeaways

• Flumazenil is a mature, genericized small molecule with no biosimilar issue.
• The standard injectable formulation uses a simple aqueous excipient system: edetate disodium, acetic acid, sodium chloride, sodium hydroxide, and water for injection.
• Core composition and conventional injectable patent protection provide limited blocking value.
• The strongest commercial opportunities are prefilled syringes, low-waste unit doses, stable emergency presentations, and alternative delivery routes.
• Intranasal flumazenil has the greatest potential for market expansion but also the highest clinical and regulatory burden.
• A conventional 505(j) generic is easier to develop but faces price and contracting pressure.
• A 505(b)(2) product could obtain differentiation through route, device, dosing system, or clinical-use claims.
• Manufacturing reliability, sterile fill-finish capacity, container compatibility, and hospital distribution are central competitive factors.

FAQs

Can flumazenil be formulated as a nasal spray?

Yes, but an intranasal product would require evidence of dose delivery, absorption, onset, repeat dosing, device performance, and clinical effectiveness. It would likely require a new-product regulatory strategy rather than a routine ANDA.

Is edetate disodium essential in flumazenil injection?

It is part of the labeled Romazicon excipient system and functions as a chelating agent. A new formulation could evaluate alternative stabilization strategies, but any change would require comparative stability and injectable safety data.

Does flumazenil have meaningful pediatric formulation potential?

Yes. Pediatric opportunity is more likely to involve low-volume syringes, calibrated dosing devices, and reduced waste than a fundamentally different excipient system. Pediatric labeling and dosing evidence would be central to the product strategy.

Could a flumazenil autoinjector obtain patent protection?

Potentially. Protection would likely focus on the device configuration, low-volume dose delivery, drug-device compatibility, and emergency-use performance rather than on flumazenil itself.

Is flumazenil vulnerable to biosimilar competition?

No. Flumazenil is a chemically synthesized small-molecule drug. Competition occurs through generic drug applications, reformulated products, and potentially 505(b)(2) products, not through the biosimilar pathway.

References

1. U.S. Food and Drug Administration. (2018). Romazicon (flumazenil) injection prescribing information. FDA.

2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

3. U.S. Food and Drug Administration. (2023). Applications covered by Section 505(b)(2). FDA.

4. U.S. Food and Drug Administration. (2024). Abbreviated new drug application process for generic drugs. FDA.

5. European Medicines Agency. (n.d.). Flumazenil and benzodiazepine antagonist product information. EMA.

6. DailyMed. (n.d.). Flumazenil injection, solution: labeling and inactive ingredients. U.S. National Library of Medicine.