List of Excipients in Branded Drug AMIDATE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Henry Schein Inc	AMIDATE	etomidate	0404-9811	WATER
Hospira Inc	AMIDATE	etomidate	0409-6695	PROPYLENE GLYCOL
Hospira Inc	AMIDATE	etomidate	0409-6695	WATER

AMIDATE Excipient Strategy and Commercial Opportunities for Etomidate Injection

Last updated: August 25, 2026

AMIDATE is an etomidate 2 mg/mL intravenous anesthetic injection. Its core formulation uses propylene glycol as the solvent, with water for injection and pH adjustment. The formulation is commercially established, inexpensive, and protected mainly by regulatory approval rather than active patent rights. The strongest commercial opportunities are reformulations that reduce propylene-glycol exposure, improve injection tolerability, simplify emergency use, or support differentiated presentations for anesthesia and critical-care settings.

What is AMIDATE and how is it formulated?

AMIDATE is the U.S. brand for etomidate injection, an intravenous induction anesthetic. Etomidate produces hypnosis with limited cardiovascular depression relative to many alternative induction agents, which supports its use in patients at risk of hemodynamic instability.[1]

The conventional AMIDATE formulation contains:

Component	Function
Etomidate, 2 mg/mL	Active pharmaceutical ingredient
Propylene glycol, approximately 35% v/v	Solvent and cosolvent
Water for injection	Vehicle
Sodium hydroxide or equivalent pH adjuster	pH control
No antimicrobial preservative	Single-dose injectable presentation

The labeled product has a pH of approximately 6.0 to 7.0 and is supplied as a sterile injectable solution, commonly in a 20 mL vial containing 40 mg of etomidate.[1]

Why is propylene glycol used in AMIDATE?

Etomidate has limited aqueous solubility. Propylene glycol allows the drug to remain in solution at the target concentration without requiring a lipid emulsion or more complex solubilization system.

The excipient performs several commercial functions:

1. It enables a clear, ready-to-use solution.
2. It supports a relatively simple manufacturing process.
3. It avoids the physical instability risks associated with emulsions.
4. It permits room-temperature storage under standard injectable-product conditions.
5. It keeps the product cost structure relatively low.

The tradeoff is that high propylene-glycol content can contribute to injection-site discomfort, hyperosmolarity, and systemic solvent exposure. Repeated or prolonged exposure may create propylene-glycol accumulation concerns, particularly in critically ill patients or those with renal or hepatic impairment. AMIDATE is generally used as a single induction dose, which limits cumulative exposure.

What excipient risks affect AMIDATE commercialization?

The main formulation risk is reliance on a high concentration of propylene glycol.

Injection pain and tolerability

Etomidate injection is associated with pain on injection and myoclonus. Propylene glycol and the solution's osmolality can contribute to local discomfort. A formulation that reduces solvent concentration without compromising solubility could obtain a meaningful commercial advantage in anesthesia and emergency medicine.

Pain reduction is commercially relevant because anesthesiologists can select among several induction agents, including propofol, ketamine, and etomidate. A product that retains etomidate's hemodynamic profile while reducing injection discomfort may compete on clinical usability rather than price.

Solvent-related safety

Propylene glycol is widely used in parenteral medicines, but exposure can produce elevated osmol gap, lactic acidosis, renal dysfunction, and other toxicity signals when administered in high cumulative amounts. These concerns are more relevant to continuous or repeated dosing than to a single induction dose.[2]

A reformulated etomidate product could target:

• Emergency departments treating high-risk patients
• Intensive-care units using repeated procedural sedation
• Pediatric populations
• Patients with renal or hepatic impairment
• Prehospital and military medicine
• Hospitals seeking lower-excipient injectable products

Particulate and physical-stability control

A clear solution has manufacturing advantages over an emulsion, but it requires tight control of:

• Etomidate precipitation
• Container-closure compatibility
• Subvisible particles
• pH drift
• Extractables and leachables
• Freeze-thaw stability
• Light exposure
• Dilution compatibility

A new excipient system would need to preserve the current product's clarity and stability while delivering a measurable clinical or operational benefit.

What formulation strategies could replace or reduce propylene glycol?

Several excipient approaches are technically plausible. Each carries different development, regulatory, and commercial implications.

Lipid emulsion formulations

A lipid emulsion can improve etomidate solubilization and reduce reliance on propylene glycol. Commercial etomidate emulsion products in some markets use oil-in-water systems containing components such as soybean oil, medium-chain triglycerides, egg phospholipids, glycerol, and pH-adjusting agents.[3]

Potential benefits include:

• Lower propylene-glycol exposure
• Potential reduction in injection pain
• Improved local tolerability
• A formulation platform familiar to anesthesia departments

Potential drawbacks include:

• More complex manufacturing
• Emulsion droplet-size control
• Greater sensitivity to shaking, storage, and handling
• Increased risk of microbial growth if container use is not tightly controlled
• Additional labeling requirements for excipient allergies
• Potential incompatibility with standard syringe and infusion practices

An emulsion product would likely be positioned as a premium formulation rather than a direct low-cost generic substitute.

Cyclodextrin-based formulations

Cyclodextrins can improve the apparent aqueous solubility of poorly water-soluble drugs. A hydroxypropyl-beta-cyclodextrin or sulfobutyl ether-beta-cyclodextrin system could reduce or eliminate propylene glycol.

The commercial case depends on several factors:

• Required cyclodextrin concentration
• Renal clearance of the complexing agent
• Compatibility with intravenous administration
• Osmolality
• Toxicology package
• Stability after dilution
• Cost relative to propylene glycol

This approach could be attractive if it produces a clear solution with lower injection pain and standard vial handling. The primary risk is that the excipient may create a new renal or toxicology issue, especially in critically ill patients.

Cosolvent blends

A lower-propylene-glycol formulation could combine ethanol, polyethylene glycol, glycerol, or other pharmaceutical-grade cosolvents. This strategy may be easier to develop than a novel emulsion, but it can shift rather than eliminate solvent-related concerns.

A cosolvent blend must be assessed for:

• Hemolysis
• Local irritation
• Cardiovascular effects
• Osmolality
• Container compatibility
• Precipitation after dilution
• Excipient exposure in pediatric patients

The commercial opportunity is strongest if a blend can reduce injection pain while maintaining a simple, transparent solution.

Lipid-free nanodispersions and advanced solubilization systems

Nanodispersions, amorphous systems, and other advanced delivery technologies may improve solubility and reduce solvent requirements. These systems could support a differentiated injectable product, but they create greater development and manufacturing complexity.

The regulatory burden would likely include extensive characterization of:

• Particle size or colloidal distribution
• Physical stability
• Aggregation
• Sterilization impact
• In-use stability
• Infusion-line compatibility

This strategy is more suitable for a specialty pharmaceutical company with injectable formulation capabilities than for a conventional generic manufacturer.

What excipients are protected by AMIDATE patents?

AMIDATE has limited current patent-based exclusivity. Etomidate is an established active ingredient, and the basic propylene-glycol injection concept is old. The commercial barrier is primarily FDA approval, manufacturing quality, supply reliability, and hospital contracting.

IP category	AMIDATE position	Commercial implication
Etomidate active ingredient	Long off-patent	No meaningful active-ingredient exclusivity
Basic propylene-glycol solution	Mature formulation technology	Limited patent differentiation
Vial presentation	Conventional injectable format	Low barrier to generic substitution
Lipid emulsion formulation	May be protected by separate third-party patents in some jurisdictions	Potential reformulation opportunity
Reduced-pain formulations	Potentially patentable if supported by composition or clinical data	Stronger lifecycle-management option
Premixed syringes or cartridges	Potential device and packaging claims	Operational differentiation
Manufacturing process	Possible process patents	Limited value without cost or quality advantage
Method of use	Existing anesthesia uses are mature	Weak exclusivity unless tied to a specific regimen or patient population

Any current freedom-to-operate assessment must distinguish between U.S. Orange Book patents, non-U.S. formulation patents, abandoned applications, and patents covering unrelated etomidate derivatives. The conventional AMIDATE formulation does not have a strong visible patent moat based solely on its excipient composition.

What is the FDA and Orange Book status of AMIDATE?

AMIDATE is an FDA-approved etomidate injectable product. The product has historically been associated with Hospira, a Pfizer company, and is identified in FDA drug databases under an approved application for etomidate injection.[1,4]

The principal regulatory characteristics are:

Regulatory element	Status
Active ingredient	Etomidate
Dosage form	Intravenous injection
Strength	2 mg/mL
FDA pathway	Approved new drug application and subsequent generic competition
Orange Book relevance	Listed etomidate products and approved applications may be substitutable depending on application status
Pediatric labeling	Use requires age-specific clinical judgment and labeling review
Preservative status	Conventional product is generally preservative-free
Controlled-substance status	Etomidate is not federally scheduled as a controlled substance in the United States, although institutional controls apply

The key regulatory opportunity is a 505(b)(2) reformulation if the sponsor can rely partly on existing etomidate safety and efficacy data while generating new data for the excipient system, delivery format, or clinical benefit. A conventional generic would generally face lower development costs but would have little basis for premium pricing.

When does AMIDATE lose exclusivity?

AMIDATE's principal exclusivity has expired because etomidate has been marketed for decades and generic etomidate injections are available. The product's commercial status is therefore different from that of a recently approved branded anesthetic.

Generic entry and Paragraph IV risk

A new generic applicant could pursue an ANDA based on pharmaceutical equivalence and bioequivalence. For an injectable solution, the development pathway may be relatively direct if the generic matches:

• Etomidate concentration
• Route of administration
• Qualitative and quantitative excipient profile, where required
• Sterility and endotoxin specifications
• Container-closure system
• Labeling requirements

Paragraph IV certification is less commercially significant for a product without a meaningful current patent estate. The major litigation risk would arise from a later-added formulation patent, delivery-device patent, or method-of-use patent, not from the basic AMIDATE product.

Biosimilar risk

Biosimilar risk is not relevant. Etomidate is a small-molecule drug, not a biologic. Competition comes through generic ANDAs, 505(b)(2) reformulations, and hospital-purchased alternatives.

How strong is the AMIDATE patent estate?

The conventional AMIDATE patent estate is weak from a lifecycle-management perspective.

A commercial assessment should assign the following characteristics:

Factor	Assessment
Composition-of-matter protection	Expired
Basic solution formulation	Low patent strength
Excipient differentiation	Moderate only if a new system is developed
Device protection	Potentially moderate for specialized delivery formats
Method-of-use protection	Limited for established induction anesthesia
Manufacturing protection	Potentially useful for cost, yield, or stability
Geographic strength	Likely strongest opportunity outside the basic U.S. generic market
Litigation leverage	Low for the legacy formulation

A stronger estate could be built around a specific formulation that demonstrates reduced pain, reduced myoclonus, lower solvent exposure, improved stability, or improved administration in emergency settings. Claims would need to cover both composition and clinically meaningful performance.

What formulation patents could protect a new etomidate product?

A lifecycle-management program could pursue claims directed to:

Composition claims

These could cover:

• Etomidate concentration ranges
• Specific lipid systems
• Cyclodextrin-to-etomidate ratios
• Reduced-propylene-glycol formulations
• pH ranges
• Surfactant combinations
• Antioxidant systems
• Preservative-free multidose approaches, if technically supportable

Composition claims generally provide the clearest infringement pathway, but they must be narrow enough to survive prior-art review and broad enough to prevent easy design-around.

Performance-based claims

A sponsor could seek protection for formulations that demonstrate:

• Lower injection pain scores
• Lower incidence or severity of myoclonus
• Reduced precipitation after dilution
• Longer in-use stability
• Lower osmolality
• Reduced compatibility failures with infusion materials

Clinical-performance claims are more commercially valuable when the benefit is statistically and clinically meaningful.

Container and device claims

Potential protection includes:

• Ready-to-administer prefilled syringes
• Autoinjector-compatible presentations
• Low-dead-space connectors
• Unit-dose emergency kits
• Light-protective packaging
• Dual-compartment systems
• Standardized anesthesia-machine cartridges

These claims may create a practical barrier even when the formulation itself is difficult to protect.

What commercial opportunities exist for AMIDATE reformulation?

The commercial market is divided between low-cost generic supply and differentiated hospital products.

Premium reduced-pain injection

A lower-pain formulation could target operating rooms, emergency departments, and procedural sedation. Etomidate's use is often determined by hemodynamic considerations, so a product that improves administration without sacrificing cardiovascular stability could command a premium.

The value proposition would need direct comparative data against conventional etomidate injection.

Propylene-glycol-reduced formulation

A lower-solvent product could target institutions concerned about cumulative excipient exposure. The most credible positioning would focus on repeated procedural dosing, critical-care use, pediatrics, and patients with impaired solvent clearance.

Ready-to-use emergency presentation

A prefilled syringe or emergency kit could improve speed, reduce preparation steps, and lower medication-error risk. This opportunity depends on:

• Stability in the device
• Syringe adsorption studies
• Needle and connector compatibility
• Tamper evidence
• Label readability
• Automated dispensing cabinet integration

The device may generate stronger differentiation than a standard vial, especially in emergency medicine and prehospital care.

Low-temperature or extended-stability product

A formulation with broader storage conditions or longer in-use stability could reduce pharmacy waste and improve availability in ambulances, military medicine, remote hospitals, and disaster-response stockpiles.

International formulation licensing

Etomidate emulsion technology and alternative solvent systems may offer licensing opportunities where the U.S. market is commoditized. A company with a validated formulation could license regional rights to established injectable manufacturers.

Potential partners include:

• Generic injectable companies
• Hospital-product manufacturers
• Anesthesia-focused specialty pharmaceutical companies
• Emergency-medicine suppliers
• Contract development and manufacturing organizations

The preferred deal structure would likely combine an upfront payment, development milestones, manufacturing supply rights, and territory-specific royalties.

How does AMIDATE compare with competing induction agents?

Product	Main formulation issue	Commercial position
AMIDATE, etomidate solution	Propylene glycol and injection pain	Low-cost, hemodynamically attractive option
Etomidate lipid emulsion	More complex manufacturing and allergy labeling	Premium reformulation opportunity
Propofol emulsion	Emulsion handling and lipid-related considerations	Broad anesthesia use, strong incumbent position
Ketamine injection	Different psychotropic and cardiovascular profile	Emergency and procedural-sedation competitor
Thiopental, where available	Reconstitution and supply limitations	Legacy alternative with narrower use

Etomidate does not compete only on price. Its primary clinical differentiation is the perceived hemodynamic profile during induction. A reformulated product should preserve that attribute while improving tolerability, handling, or excipient exposure.

What generic launch risks exist for AMIDATE?

Generic launch risk is high for the legacy formulation because:

• The active ingredient is off patent.
• The dosage form is technically established.
• Hospital buyers often purchase through contracts.
• Multiple injectable manufacturers can compete on supply and price.
• A conventional vial offers limited brand differentiation.

The principal barriers are manufacturing quality and reliable supply rather than patent litigation. Sterile injectable recalls, shortage events, and manufacturing disruptions can rapidly change market share. A supplier with redundant manufacturing capacity may obtain more value than one with a marginally different excipient profile.

What manufacturing and IP barriers affect new etomidate products?

The main manufacturing barriers are:

1. Sterile filtration or aseptic processing validation.
2. Control of precipitation during filling and storage.
3. Container-closure compatibility.
4. Emulsion droplet-size control, where applicable.
5. Particulate and endotoxin compliance.
6. Compatibility with syringes, needles, and infusion lines.
7. Stability after opening or dilution.
8. Commercial-scale reproducibility.

For an emulsion or advanced solubilization system, the critical quality attributes may be more complex than those of the conventional solution. That can increase regulatory review time and create supply-chain dependence on specialized excipients.

The strongest IP strategy would combine:

• Composition claims
• Process claims
• Device claims
• Stability claims
• Clinical-performance claims
• Geographic filings in major anesthesia markets

What is the revenue exposure for AMIDATE?

Public product-level revenue for AMIDATE is not generally disclosed separately from broader injectable anesthetic portfolios. The legacy product should be treated as a mature, price-sensitive hospital product rather than a high-growth branded asset.

Revenue exposure is most sensitive to:

• Generic price erosion
• Hospital contracting
• Injectable shortages
• Operating-room procedure volumes
• Emergency-department use
• Availability of competing etomidate products
• Supply reliability
• Adoption of lipid or lower-solvent alternatives

A reformulated product could expand revenue per unit, but only if it demonstrates a clear benefit over generic etomidate. Without comparative clinical evidence, hospitals are likely to treat the product as therapeutically substitutable and resist a premium.

Key Takeaways

• AMIDATE is a 2 mg/mL etomidate injection using propylene glycol as the principal solvent.
• The legacy formulation has weak patent protection and faces generic competition.
• Propylene glycol creates the clearest excipient-based opportunity because of injection pain, osmolality, and cumulative-exposure concerns.
• Lipid emulsions, cyclodextrins, and lower-solvent cosolvent systems are the leading reformulation paths.
• A 505(b)(2) strategy may support a differentiated product with new clinical or handling benefits.
• Prefilled syringes, emergency kits, and improved storage stability may provide stronger commercial differentiation than a simple excipient substitution.
• Biosimilar risk does not apply because etomidate is a small molecule.
• The main commercial barriers are sterile manufacturing, supply reliability, hospital contracting, and proof of clinical benefit.
• A new product should seek composition, process, device, stability, and performance claims across the United States, Europe, Japan, and other major injectable markets.

FAQs

Can propylene glycol be removed completely from AMIDATE?

Yes, in principle. A lipid emulsion, cyclodextrin complex, or alternative solubilization system could replace it, but the new formulation would require separate stability, safety, compatibility, and regulatory evaluation.

Would a lower-pain etomidate formulation receive new market exclusivity?

Potentially. A novel formulation supported by clinical evidence could qualify for patent protection and may be submitted through a 505(b)(2) application. Regulatory exclusivity would depend on the approval pathway and the specific data package.

Is an etomidate emulsion commercially superior to AMIDATE solution?

Not automatically. An emulsion may reduce solvent exposure or injection discomfort, but it has higher manufacturing complexity, greater packaging requirements, and potential excipient-allergy considerations.

Can a generic manufacturer copy AMIDATE's excipients?

A generic applicant may be able to use the same or substantially equivalent excipient system, subject to FDA requirements for injectable products. The applicant must establish pharmaceutical equivalence, quality, sterility, and bioequivalence or the applicable waiver standard.

What is the best licensing opportunity around AMIDATE?

The strongest licensing opportunity is a validated, ready-to-use or reduced-propylene-glycol etomidate formulation with comparative evidence showing lower injection pain, lower excipient exposure, improved stability, or faster emergency administration.

References

1. U.S. Food and Drug Administration. (2023). AMIDATE (etomidate injection, USP) prescribing information. Hospira, Inc.

2. U.S. Food and Drug Administration. (2011). Safety assessment of propylene glycol when used as an excipient in pharmaceuticals. FDA.

3. B. Braun Melsungen AG. (2023). Etomidate-Lipuro 2 mg/mL emulsion for injection: Summary of product characteristics. European Medicines Agency and national product information.

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA.