List of Excipients in Branded Drug DIPRIVAN

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Fresenius Kabi USA LLC	DIPRIVAN	propofol	63323-269	EDETATE DISODIUM ANHYDROUS
Fresenius Kabi USA LLC	DIPRIVAN	propofol	63323-269	EGG PHOSPHOLIPIDS
Fresenius Kabi USA LLC	DIPRIVAN	propofol	63323-269	GLYCERIN
Fresenius Kabi USA LLC	DIPRIVAN	propofol	63323-269	SODIUM HYDROXIDE
Fresenius Kabi USA LLC	DIPRIVAN	propofol	63323-269	SOYBEAN OIL

DIPRIVAN Excipient Strategy and Commercial Opportunities

Last updated: August 22, 2026

Diprivan is a propofol injectable emulsion whose commercial value depends less on active-ingredient exclusivity than on formulation quality, emulsion stability, microbial control, container compatibility, supply reliability, and differentiated presentation. The reference product uses soybean oil, egg lecithin, glycerol, water, sodium hydroxide, and disodium edetate in a 10 mg/mL sterile lipid emulsion.[1] Propofol has long been subject to generic competition, and the principal opportunities now involve hospital supply, preservative-controlled formulations, ready-to-use delivery systems, specialty anesthesia products, and manufacturing efficiency.

What excipients are used in Diprivan?

Diprivan contains propofol at 10 mg/mL in a lipid emulsion. The formulation is designed to solubilize the highly lipophilic active ingredient while permitting intravenous administration.

Component	Function in the formulation	Commercial or technical relevance
Propofol	Active anesthetic	10 mg/mL concentration
Soybean oil	Lipid vehicle and solvent phase	Controls drug solubilization, emulsion structure, and caloric load
Egg lecithin	Emulsifier	Supports oil-in-water emulsion stability
Glycerol	Tonicity-adjusting agent	Helps achieve physiological osmolality
Disodium edetate, or EDTA	Antimicrobial-supporting and chelating excipient	Reduces metal-catalyzed degradation and supports microbial-control strategy
Sodium hydroxide	pH adjustment	Maintains the target pH range
Water for injection	Continuous aqueous phase	Sterile vehicle

The United States label identifies soybean oil, glycerol, egg lecithin, disodium edetate, sodium hydroxide, and water for injection as inactive ingredients. The emulsion has a pH of approximately 6.0 to 8.5 and is supplied as a sterile, white oil-in-water emulsion.[1]

The excipient system is central to product performance. Propofol is poorly water soluble, so a conventional aqueous injection is not practical at the marketed concentration. The lipid phase provides solubilization, while lecithin creates the interfacial film needed to maintain dispersed oil droplets.

How does the Diprivan formulation work?

Diprivan uses a submicron oil-in-water emulsion. Propofol is dissolved in the soybean oil phase, and egg lecithin stabilizes the oil droplets in the aqueous phase. Glycerol adjusts tonicity, while EDTA supports product robustness against trace-metal effects and contributes to the formulation's microbial-control profile.

The key quality attributes are:

• Droplet-size distribution
• Mean droplet diameter
• Large-diameter tail, often evaluated through PFAT5-type measurements
• Propofol assay and impurities
• pH and osmolality
• Emulsion cracking, creaming, or phase separation
• Sterility and bacterial-growth control
• Container closure integrity
• Extractables and leachables
• Particulate matter
• Freeze-thaw and temperature stability

For an injectable emulsion, matching the nominal ingredient list is not enough. A competing product must demonstrate comparable physical characteristics, sterility assurance, stability, and clinical performance under the applicable abbreviated or full application pathway.

What excipient strategy creates the strongest commercial position?

The strongest strategy is usually an equivalent or highly similar emulsion with measurable improvements in handling, microbial control, supply resilience, or administration efficiency.

1. Preserve the established lipid-emulsion platform

A soybean-oil and lecithin system has the lowest clinical and regulatory risk because it is aligned with the reference product and with extensive clinical use. A reformulated product using alternative lipids, surfactants, or mixed oils may create differentiation but also increases development requirements.

A generic manufacturer should prioritize:

• Comparable emulsion droplet size
• Comparable pH and osmolality
• Consistent propofol loading
• Low peroxide and aldehyde formation
• Low visible and subvisible particulate burden
• Robust terminal sterilization or aseptic-processing controls
• Stable performance across the labeled storage period

The formulation must remain injectable through standard anesthesia workflows. Excessive viscosity, difficult syringe withdrawal, or increased foaming can create hospital-use disadvantages even if the analytical profile is acceptable.

2. Evaluate EDTA and preservative strategy carefully

Propofol emulsions have historically presented microbial-growth concerns because they contain lipid and are administered in high-acuity settings. Diprivan labeling requires strict handling and limits the time that a vial or syringe may remain in use after opening.[1]

EDTA can improve microbial-control performance and bind trace metals, but it does not remove the need for aseptic handling and labeled discard times. A manufacturer considering a preservative-free presentation must generate a stronger microbiological and stability package. A product containing an alternative antimicrobial strategy may face compatibility, toxicity, and regulatory scrutiny.

The commercial opportunity is not simply to add a preservative. It is to deliver a formulation and package combination that reduces contamination risk without creating new clinical restrictions.

3. Consider alternative lipid systems only where the benefit is material

Potential alternatives include:

• Medium-chain triglycerides
• Mixed medium- and long-chain triglycerides
• Structured lipids
• Alternative phospholipids
• Synthetic emulsifiers
• Reduced-lipid or lipid-free systems
• Nanoemulsion or solvent-based approaches

These platforms could reduce dependence on soybean oil or egg-derived components, alter the caloric profile, improve tolerability, or support a novel presentation. They also introduce additional technical risks involving droplet stability, injection-site tolerability, infusion behavior, impurity formation, and regulatory comparability.

A reformulation must produce a clinically relevant benefit. Removing egg or soybean-derived excipients could have commercial value for institutions seeking a differentiated product, but the clinical significance of reported food-allergy concerns must be evaluated against labeling, medical practice, and actual product exposure.

What formulations are protected by Diprivan-related patents?

Diprivan's original formulation and manufacturing exclusivity are historical rather than current commercial barriers. Propofol was approved in the United States in 1989, and generic propofol injectable emulsions have been marketed for many years.[2] The core composition and early process patents associated with Diprivan have expired.

Area	Current commercial significance
Basic propofol injectable emulsion	Core exclusivity expired; generic competition established
Soybean-oil and lecithin composition	Mature formulation technology
EDTA-containing formulation	May be relevant to product identity and development history, but not a practical barrier by itself
Prefilled syringe or ready-to-use presentation	Potentially protectable through device, packaging, process, or combination claims
Alternative lipid emulsion	Possible new patent space if claims cover composition and performance
Microbial-control method	Possible patent space, subject to claim scope and obviousness
Manufacturing process	Potential protection where process parameters create a demonstrated quality advantage
New dosage form or delivery device	Potentially protectable if it provides a non-obvious clinical or operational benefit

The commercially important patent question is therefore not whether Diprivan's original basic formulation remains blocking. It is whether a competitor's improved presentation or formulation is covered by later, independently owned patents. Those risks must be analyzed product by product.

When did Diprivan lose exclusivity?

Diprivan lost practical market exclusivity after the expiration of its original patent and regulatory protections, followed by approval of generic propofol injectable emulsions. The active ingredient is a small molecule, not a biologic, so biosimilar exclusivity does not apply.

Exclusivity category	Diprivan status
New chemical entity exclusivity	Expired
Original product patent protection	Expired
Pediatric exclusivity	No current commercial effect
Orphan-drug exclusivity	Not applicable to the core product
Biologic reference-product exclusivity	Not applicable
Generic competition	Established
Current Orange Book blocking position	No material core exclusivity barrier identified

The relevant regulatory route for competitors is the abbreviated new drug application, or ANDA, when the product can meet the applicable requirements for sameness and bioequivalence. A substantially reformulated product may require a different regulatory pathway.

What is the Orange Book status of Diprivan?

Diprivan is a prescription injectable drug listed in FDA drug-product databases. The Orange Book is relevant to identifying reference-listed-drug status, approved strengths, dosage forms, patents, and exclusivity.[3]

For Diprivan, the principal business conclusion is that the reference product does not control the propofol injection market through an active core patent estate. Generic manufacturers compete on price, manufacturing reliability, contract supply, hospital formulary access, and presentation.

Orange Book analysis remains important for:

• Confirming the reference-listed drug
• Reviewing any listed patent information
• Assessing exclusivity codes
• Mapping approved dosage forms and strengths
• Comparing ANDA approvals
• Identifying potential 30-month-stay exposure from a Paragraph IV filing

Which companies are challenging Diprivan with generic propofol?

Generic propofol has been supplied by multiple manufacturers and contract manufacturers over time. The competitive field has included major injectable-drug companies such as Fresenius Kabi, Hikma, Pfizer, Sagent, and other approved ANDA holders or distributors, depending on market and period.[4]

The market is fragmented by:

• Vial size
• Single-dose versus pharmacy-bulk packaging
• Ready-to-use syringe availability
• Hospital-contract status
• Regional manufacturing footprint
• Shortage history
• Purchasing-group relationships
• Formulary and anesthesia-department preferences

Market share can change quickly when one manufacturer experiences a sterile injectable shortage or production interruption. This makes manufacturing resilience a commercial asset even where the molecule is fully genericized.

How do Paragraph IV challenges affect Diprivan?

Paragraph IV litigation has the greatest relevance when a listed patent remains active and an ANDA applicant certifies that the patent is invalid, unenforceable, or not infringed. Because the foundational Diprivan patents are expired, current generic entry is more likely to involve ordinary ANDA competition than litigation over core composition claims.

Potential Paragraph IV exposure could still arise for:

• A later-listed formulation patent
• A new delivery device
• A patented prefilled syringe
• A method-of-use patent
• A process patent that is relevant to an ANDA product
• A later reformulation marketed under a separate product identifier

For a commercial entrant, the litigation risk is likely to be concentrated in device, packaging, or differentiated formulation claims rather than in propofol itself.

What method-of-use patents protect propofol products?

Propofol's major clinical uses include induction and maintenance of general anesthesia and monitored anesthesia care sedation. These uses are well established and have been practiced for decades. Broad method-of-use protection for standard anesthesia administration is unlikely to provide a durable barrier against generic propofol.

Potentially narrower claim areas include:

• Specific dosing regimens
• Sedation protocols
• Patient-selection criteria
• Combination use with other anesthetics or analgesics
• Closed-loop or target-controlled infusion systems
• Recovery-time or adverse-event reduction methods
• Use in specialized procedural settings

A method patent must offer a legally enforceable distinction from established clinical practice. Routine changes in dose, timing, or patient setting may face validity challenges if they lack unexpected technical or clinical results.

What patent opportunities exist for new propofol excipients?

The most credible patent opportunities involve a defined technical problem and measurable performance improvement.

Excipient and composition claims

Potential claim themes include:

• A specified lipid blend
• A defined phospholipid concentration
• A narrow droplet-size distribution
• Reduced large-droplet content
• A non-soybean lipid phase
• A synthetic or recombinant emulsifier
• A formulation with reduced free propofol
• A composition with improved oxidative stability
• A formulation with reduced injection pain
• A formulation compatible with a prefilled syringe

Composition claims are stronger when the excipient combination creates an unexpected result. A simple substitution of one conventional lipid for another may face obviousness challenges.

Process claims

Manufacturing claims may cover:

• High-pressure homogenization parameters
• Temperature and shear controls
• Order of ingredient addition
• Deoxygenation procedures
• Nitrogen overlay
• Control of peroxide value
• Sterilization conditions
• Aseptic filling into low-sorption containers

Process patents can create a barrier if the claimed process is necessary to achieve a distinctive quality attribute. They have less value when competing manufacturers can reach the same product profile through alternative processes.

Device and packaging claims

The most commercially practical patent space may be in:

• Ready-to-administer syringes
• Needle-free connectors
• Low-dead-volume systems
• Tamper-evident single-dose packaging
• Syringe systems that limit emulsion disruption
• Automated anesthesia-delivery compatibility
• Packaging that reduces oxygen exposure

These claims can support premium pricing if hospitals obtain measurable workflow or waste-reduction benefits.

What commercial opportunities exist beyond generic Diprivan?

Ready-to-use presentations

Anesthesia departments value products that reduce preparation steps and contamination opportunities. A prefilled syringe or standardized ready-to-administer container could command a premium if it has acceptable stability, labeling, and device compatibility.

The main development constraints are:

• Long-term emulsion stability in the syringe
• Silicone oil and lubricant compatibility
• Plunger and stopper extractables
• Adsorption or absorption of propofol
• Accurate dose delivery
• Sterility assurance
• Human-factors validation

Supply-secure hospital contracts

A manufacturer can compete without patent differentiation by offering dual-site production, validated backup capacity, and reliable allocation during shortages. Propofol is a high-use hospital anesthetic, so procurement departments place substantial value on continuity.

Reduced-waste packaging

Small-volume vials, prefilled syringes, and packaging matched to procedure duration can reduce unused product. The value proposition is strongest where the product decreases waste while maintaining a competitive acquisition price.

Specialty anesthesia formulations

Opportunities include formulations intended to reduce injection pain, improve emulsion stability, or support controlled infusion. These products require clinical evidence and may compete in a narrower premium segment.

International markets

Geographic opportunities vary because regulatory standards, procurement systems, and approved excipients differ. The United States emphasizes FDA quality and ANDA requirements. Europe requires compliance with the applicable marketing-authorization framework and pharmacopoeial standards. Emerging markets may have greater sensitivity to price and supply continuity.

A global strategy should assess:

• Local reference-product status
• Patent and supplementary-protection-certificate history
• Excipient acceptability
• Pharmacopoeial requirements
• Cold-chain or controlled-storage needs
• Hospital tender structure
• Local sterile-manufacturing capacity

How strong is the Diprivan patent estate?

The core Diprivan patent estate is weak as a current barrier because the foundational propofol emulsion technology is mature and genericized. The stronger protection opportunities belong to later products with new compositions, devices, or manufacturing processes.

Patent category	Estimated current strength
Basic propofol composition	Low
Conventional soybean-oil emulsion	Low to moderate, depending on claim scope
EDTA-containing formulation	Low as a standalone barrier
Alternative lipid system	Moderate if supported by unexpected performance
Prefilled syringe	Moderate to high if device claims are specific
Microbial-control system	Moderate if supported by data
Manufacturing process	Moderate, but vulnerable to design-around
New clinical method	Variable and indication-dependent

The key diligence issue is freedom to operate around active third-party patents covering emulsion parameters, packaging materials, prefilled devices, and manufacturing equipment.

What generic launch risks exist for propofol products?

The primary risks are operational rather than molecule-related.

Manufacturing and quality risks

• Emulsion instability during scale-up
• Batch-to-batch droplet-size variation
• Oxidative degradation
• Sterility failures
• Particulate contamination
• Container closure failures
• Inadequate hold-time validation
• Shortage of pharmaceutical-grade phospholipids or oils

Regulatory risks

• Failure to demonstrate equivalent product quality
• Inadequate characterization of the emulsion
• Incomplete extractables and leachables assessment
• Unsupported preservative or microbial-control claims
• Inconsistent labeling for single-dose handling
• Device compatibility failures for prefilled presentations

Commercial risks

• Low generic pricing
• Dependence on group purchasing organizations
• Hospital contract concentration
• Competition from established injectable manufacturers
• Limited differentiation between vial products
• Rapid margin erosion after launch

The most defensible launch model combines a standard ANDA product with a differentiated package, multiple manufacturing sites, and a supply agreement targeted at hospitals or anesthesia distributors.

What FDA regulatory status applies to Diprivan and new propofol products?

Diprivan is an FDA-approved propofol injectable emulsion. Generic competitors generally pursue the ANDA route when they can demonstrate pharmaceutical equivalence, bioequivalence, and adequate chemistry, manufacturing, and controls data.[1,2]

A new excipient strategy can change the regulatory path. A product that materially changes the formulation, delivery system, or clinical use may require more extensive clinical or comparative data. FDA expectations will center on:

• Identity and strength
• Emulsion characterization
• Sterility
• Stability
• Container closure integrity
• In-use handling
• Comparative performance
• Labeling of excipient-related risks
• Manufacturing-process control

Because propofol emulsions are complex sterile products, formulation development and process validation are likely to determine approval timing and launch reliability.

Key Takeaways

• Diprivan is a 10 mg/mL propofol oil-in-water emulsion containing soybean oil, egg lecithin, glycerol, EDTA, sodium hydroxide, and water for injection.
• The core product is long genericized, and original Diprivan exclusivity is no longer a material market barrier.
• The most valuable excipient strategies involve stability, microbial control, reduced injection pain, alternative lipid systems, and ready-to-use delivery.
• EDTA supports the established formulation strategy but does not eliminate aseptic handling requirements.
• Prefilled syringes and low-waste packaging offer stronger commercial differentiation than a conventional vial.
• Patent opportunities are concentrated in new compositions, emulsion-process controls, packaging, devices, and narrow clinical methods.
• Biosimilar risk does not apply because propofol is a small-molecule drug.
• Generic-launch risk is driven mainly by sterile manufacturing, emulsion quality, supply reliability, hospital contracting, and price pressure.
• The strongest business case is a supply-secure propofol product with a validated presentation that reduces pharmacy or anesthesia workflow burden.

FAQs

Can a propofol product avoid soybean oil and egg lecithin?

Yes. A developer can pursue an alternative lipid or surfactant system, but the change increases formulation, toxicology, stability, and regulatory requirements. The commercial value depends on demonstrating a clinically or operationally meaningful benefit.

Does EDTA make Diprivan multidose?

No. EDTA supports antimicrobial control, but the product remains subject to strict single-dose or in-use handling requirements in the FDA labeling.[1]

Is a propofol prefilled syringe patentable?

Potentially. Patentability may arise from the syringe configuration, emulsion stability, low-dead-volume delivery, oxygen-control system, or compatibility between the formulation and device. Broad claims covering only the concept of a prefilled propofol syringe may be vulnerable.

Are propofol products exposed to biosimilar competition?

No. Propofol is a chemically synthesized small molecule. Competition occurs through generic drug applications, not the biosimilar pathway.

What is the highest-value formulation improvement for propofol?

A stable, ready-to-administer presentation that reduces contamination risk, preparation time, and product waste has the clearest commercial potential. A new excipient alone is less valuable unless it produces measurable clinical or manufacturing advantages.

References

1. U.S. Food and Drug Administration. (2023). Diprivan (propofol) injectable emulsion prescribing information. FDA.
2. U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs, Diprivan and propofol injectable emulsion records. FDA.
3. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: The Orange Book. FDA.
4. DailyMed. (2024). Propofol injectable emulsion product labeling. National Library of Medicine.