List of Excipients in Branded Drug BYFAVO

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Acacia Pharma Ltd	BYFAVO	remimazolam besylate	71390-011	DEXTRAN 40	2027-07-10
Acacia Pharma Ltd	BYFAVO	remimazolam besylate	71390-011	HYDROCHLORIC ACID	2027-07-10
Acacia Pharma Ltd	BYFAVO	remimazolam besylate	71390-011	LACTOSE MONOHYDRATE	2027-07-10
Acacia Pharma Ltd	BYFAVO	remimazolam besylate	71390-011	SODIUM HYDROXIDE	2027-07-10

BYFAVO Excipient Strategy and Commercial Opportunities

Last updated: August 1, 2026

BYFAVO is an injectable remimazolam besylate product whose commercial position depends on rapid reconstitution, short procedural sedation, aseptic manufacturing, and operating-room workflow. Its core excipient system is intentionally simple: glycine and mannitol support the lyophilized 20-mg vial, while hydrochloric acid and sodium hydroxide control pH during manufacture. The most credible commercial opportunities are improved ready-to-use presentations, reduced preparation burden, longer in-use stability, and differentiated packaging rather than cosmetic excipient substitution.

What is BYFAVO and how is it formulated?

BYFAVO contains remimazolam besylate, an ultra-short-acting benzodiazepine approved for induction and maintenance of procedural sedation in adults undergoing procedures lasting 30 minutes or less.[1]

The U.S. product is supplied as a sterile, preservative-free, single-dose lyophilized powder in a 20-mg vial. Healthcare professionals reconstitute the vial with 8.2 mL of sterile water for injection to produce a 2.5-mg/mL solution.[1]

Attribute	BYFAVO specification
Active ingredient	Remimazolam besylate
Dosage form	Lyophilized injectable powder
Strength	20 mg per vial
Reconstituted concentration	2.5 mg/mL
Route	Intravenous
Preservative	None
Key excipients	Glycine and mannitol
pH modifiers	Hydrochloric acid and sodium hydroxide
Indication	Induction and maintenance of procedural sedation in adults
Reconstitution diluent	Sterile water for injection
Administration setting	Procedural and ambulatory care environments

The label identifies glycine and mannitol as inactive ingredients. Their quantities are approximately 15 mg glycine and 198 mg mannitol per vial.[1] Hydrochloric acid and sodium hydroxide are used for pH adjustment rather than as the principal bulking or buffering system.

What excipients protect the BYFAVO formulation?

Glycine and mannitol perform different functions in the lyophilized cake.

Mannitol as a bulking agent

Mannitol provides cake structure and increases the physical bulk of the freeze-dried product. It is widely used in parenteral lyophilization because it can form a visually acceptable cake and is generally compatible with many small-molecule drug substances.

Its principal formulation risks are:

• Crystallization during freezing or storage
• Phase separation from the active ingredient
• Cake collapse if the product temperature exceeds the formulation’s critical temperature during primary drying
• Changes in reconstitution time or cake appearance across manufacturing scale
• Potential impact on remimazolam stability if the active and mannitol segregate during freezing

A commercial reformulator would need to control mannitol polymorphism, freeze rate, nucleation behavior, residual moisture, and vial fill weight. These parameters can affect both reconstitution performance and long-term stability.

Glycine as a stabilizing and matrix-forming excipient

Glycine can contribute to the physical structure of the lyophilized cake and influence the local chemical environment around remimazolam besylate. In the BYFAVO composition, glycine is used at a relatively low mass compared with mannitol.

Glycine-based systems can present formulation-development questions involving:

• pH drift during freezing and drying
• Solid-state interactions with the active ingredient
• Buffer capacity after reconstitution
• Reconstitution clarity
• Residual moisture and storage stability

The commercial value of the glycine-mannitol combination is its simplicity. It limits excipient burden while supporting a small-volume vial intended for rapid use.

Hydrochloric acid and sodium hydroxide

The two pH-adjusting agents allow the manufacturer to set the final formulation pH without adding a larger conventional buffer system. This approach can reduce ionic load and simplify the lyophilized formulation.

A reformulator should not assume that pH adjustment is noncritical. Remimazolam stability, degradation products, reconstitution time, visual appearance, and container-closure compatibility may all depend on the final pH range.

Why does BYFAVO use a lyophilized vial instead of a ready-to-use liquid?

The lyophilized vial likely provides a stability advantage for a water-sensitive injectable formulation and reduces the time that remimazolam remains in an aqueous environment during storage. It also allows a compact, single-dose presentation with a relatively simple excipient system.

The tradeoff is preparation burden. Each vial requires:

1. Transfer of sterile water for injection.
2. Gentle mixing or handling to dissolve the cake.
3. Verification of solution clarity.
4. Withdrawal into a syringe or administration system.
5. Use within the labeled in-use period.

This workflow creates commercial value for alternative presentations. In procedural sedation, the cost of a vial is only one part of the economic equation. Preparation time, medication errors, nursing workload, vial waste, and delayed procedure starts can materially affect purchasing decisions.

What excipient strategies could improve BYFAVO?

The most commercially relevant strategies fall into four categories.

Ready-to-use liquid formulation

A ready-to-use remimazolam injection could eliminate reconstitution and reduce manipulation in endoscopy, interventional radiology, ambulatory surgery, and emergency departments.

The formulation would need to solve several technical problems:

• Aqueous chemical stability over the proposed shelf life
• Control of degradation products
• Compatibility with common syringe and IV-bag materials
• Low particulate burden
• Sterility assurance
• Protection from adsorption to administration components
• Acceptable pH and injection tolerability
• Preservation of the intended rapid onset and offset

A ready-to-use product would probably require more than simple excipient substitution. It could involve a different concentration, pH range, cosolvent system, stabilizer, antioxidant, or container-closure configuration. That creates a potential 505(b)(2) or supplemental-application pathway, depending on the scope of the changes and the sponsor’s reference-product strategy.

Higher-concentration vial

The marketed 2.5-mg/mL reconstituted solution may not be optimal for every procedure. A higher-concentration presentation could reduce injection volume and improve compatibility with syringe pumps or constrained procedural workflows.

The main risks include dosing errors, accidental rapid administration, local tolerability, and the need to validate the product’s pharmacokinetic and safety profile if the concentration changes materially.

Premixed syringe or cartridge

A prefilled syringe could target anesthesia departments and high-throughput procedure centers. A cartridge could support an automated drug-delivery device or syringe pump.

The commercial barriers are significant:

• Device-drug combination-product requirements
• Extractables and leachables
• Silicone oil and stopper compatibility
• Needle and syringe dead volume
• Dose accuracy
• Container-closure integrity
• Stability under transport and temperature excursions
• Human-factors validation

This strategy has stronger commercial differentiation than a conventional vial but requires a larger development and regulatory program.

Extended in-use stability

The existing product is designed for preparation and use within a defined period. An excipient or packaging program that extends the post-reconstitution period could reduce wastage and support pharmacy batch preparation.

Potential approaches include:

• Optimized pH control
• Low-oxygen filling or nitrogen overlay
• Light-protective packaging
• Alternative syringe and stopper materials
• Antioxidant screening
• Lower headspace oxygen
• Improved cold-chain handling
• Ready-to-use sterile filling

The sponsor would need to demonstrate chemical, physical, microbiological, and container-closure stability under the proposed use conditions.

What formulation patents could protect a BYFAVO competitor?

A reformulated remimazolam product could obtain patent protection around a narrower technical feature rather than the active ingredient itself.

Potential claim categories include:

Patent category	Potential protected subject matter
Composition	Remimazolam with a defined excipient ratio, pH, concentration, or stabilizer
Lyophilization	Freeze-drying cycle, cake structure, residual moisture, or crystallinity profile
Liquid formulation	Aqueous stability system, pH range, buffer, antioxidant, or cosolvent
Container closure	Specific vial, syringe, stopper, cartridge, or oxygen-control configuration
Delivery system	Prefilled syringe, automated injector, pump, or procedural sedation kit
Use	Reduced preparation time, specific procedural setting, or dosing regimen
Manufacturing	Sterile filtration, filling, freezing, drying, or scale-up process

The strongest formulation patent claims usually link a composition to measurable performance, such as a defined impurity profile, stability period, reconstitution time, or particulate level. Broad claims covering glycine and mannitol alone would face substantial prior-art exposure because both are established parenteral excipients.

What is the FDA regulatory status and Orange Book position of BYFAVO?

The FDA approved BYFAVO in July 2020 under NDA 212295 for procedural sedation in adults.[2] The product is a small-molecule injectable drug, not a biologic, so biosimilar pathways do not apply.

BYFAVO received new chemical entity exclusivity associated with its initial FDA approval. The five-year NCE period began on the approval date, subject to the statutory rules governing abbreviated applications and patent certifications.[3]

The Orange Book position is relevant to generic entry because listed patents can require an ANDA applicant to make a Paragraph IV certification. Orange Book listings can change through patent listing, delisting, expiration, litigation outcomes, and regulatory updates. Any launch assessment should therefore use the current FDA Orange Book record for NDA 212295 rather than rely on an old patent summary.[4]

When does BYFAVO lose exclusivity?

The principal regulatory exclusivity period began with the July 2020 approval. The five-year NCE period would generally run to approximately July 2025, subject to statutory date calculations and any applicable extensions.[3]

Regulatory exclusivity and patent protection are separate.

Protection type	Commercial effect
NCE exclusivity	Can delay certain ANDA submissions during the protected period
Listed patents	Can trigger Paragraph IV litigation and a potential 30-month stay
Pediatric exclusivity	Could add six months if granted under the applicable program
Orphan exclusivity	Not the primary protection associated with the approved procedural-sedation indication
Formulation patents	Can protect a particular presentation after core exclusivity ends
Method-of-use patents	Can create narrower barriers tied to dosing or procedure type

The expiration of NCE exclusivity does not automatically authorize generic launch. A generic applicant must still address listed patents, demonstrate pharmaceutical equivalence and bioequivalence where applicable, and obtain FDA approval.

What generic entry risks exist for BYFAVO?

BYFAVO has a more complicated generic pathway than a conventional oral tablet because it is a lyophilized injectable that requires reconstitution.

Potential generic strategies include:

Same-formulation ANDA

An applicant could seek an ANDA for a product matching the reference listed drug in active ingredient, strength, dosage form, route, and key inactive ingredients. The applicant would need to address product quality, sterility, reconstitution, container closure, and bioequivalence requirements.

Formulation-focused Paragraph IV challenge

A generic company could challenge listed formulation or manufacturing patents while maintaining the reference product’s essential characteristics. The economic incentive would depend on whether the patent claims cover the commercial vial, reconstituted solution, manufacturing process, or use.

505(b)(2) product

A 505(b)(2) applicant could pursue a differentiated liquid, prefilled syringe, higher-concentration product, or new delivery system while relying partly on FDA findings for remimazolam. This route may offer greater product differentiation but can require additional clinical, human-factors, device, and stability data.

Hospital-use substitution risk

Even without a directly substitutable ANDA, a differentiated remimazolam product could compete for formulary position if it lowers preparation time or reduces waste. That creates commercial pressure before full generic substitution occurs.

Which companies compete with BYFAVO?

BYFAVO competes primarily with other procedural sedation and short-acting anesthetic products, not only with potential remimazolam generics.

Product	Active ingredient	Main commercial distinction
BYFAVO	Remimazolam	Rapid-onset, short-acting benzodiazepine with flumazenil reversibility
Versed	Midazolam	Established benzodiazepine with broad procedural use
Diprivan and generics	Propofol	Rapid onset, widely used, but requires deeper anesthesia monitoring
Precedex	Dexmedetomidine	Sedation product with different hemodynamic and respiratory profile
Ketamine products	Ketamine	Dissociative anesthesia and analgesia, different clinical use profile

The commercial case for BYFAVO is strongest where clinicians value rapid titration, predictable recovery, and benzodiazepine reversibility. The product must still overcome the established purchasing position of generic midazolam and the procedural familiarity of propofol.

How strong is the BYFAVO patent estate?

The commercial strength of the estate depends less on the basic presence of glycine and mannitol than on claim scope around the active compound, pharmaceutical form, formulation, manufacturing process, and approved use.

A practical strength assessment should examine:

1. Whether the claims cover the marketed 20-mg vial.
2. Whether claims cover only a narrow excipient ratio or a broader formulation range.
3. Whether the claims cover the lyophilized product, reconstituted solution, or both.
4. Whether manufacturing claims are difficult to design around.
5. Whether Orange Book-listed patents correspond directly to the approved product.
6. Whether a generic can use a different excipient system without infringing.
7. Whether a 505(b)(2) product can avoid the listed claims through a different dosage form.
8. Whether prior art discloses mannitol-glycine parenteral systems or analogous benzodiazepine formulations.

Excipient patents are most defensible when they claim an unexpected stability or manufacturing result. A claim limited to conventional excipients without a demonstrated technical effect is more vulnerable to obviousness and enablement challenges.

What licensing opportunities exist around BYFAVO?

The most attractive licensing opportunities are likely to involve product presentation and manufacturing rather than a simple copy of the marketed vial.

Potential deal structures include:

• Regional rights for a ready-to-use remimazolam formulation
• Hospital-channel rights for prefilled syringes
• Co-development of a syringe or cartridge presentation
• Contract manufacturing of lyophilized vials
• Licensing of aseptic fill-finish capacity
• Device integration for automated sedation delivery
• Formulation licensing for extended in-use stability
• Distribution agreements in markets where procedural sedation demand is expanding

A licensee would need to evaluate whether the proposed formulation is protected by composition patents, whether the product requires a new clinical package, and whether the device changes convert the product into a combination product.

What manufacturing and IP barriers affect commercial entry?

The principal manufacturing barriers are technical execution and regulatory comparability.

Lyophilized-vial barriers

A competitor must establish:

• Consistent nucleation and freezing
• Uniform cake appearance
• Controlled residual moisture
• Reproducible reconstitution time
• Low particulate levels
• Sterile fill-finish performance
• Container-closure integrity
• Stability through distribution

Small changes in excipient grade, vial geometry, fill volume, shelf temperature, or stoppering conditions can change product performance.

Ready-to-use-liquid barriers

A liquid product faces a different risk profile:

• Faster degradation in water
• Greater sensitivity to oxygen and light
• Higher container-interaction risk
• More demanding sterility and endotoxin controls
• Greater pressure on shelf-life validation
• Potential need for new clinical or bridging studies

These barriers create opportunities for specialized injectable formulation companies, lyophilization contractors, prefilled-syringe manufacturers, and packaging suppliers.

What is the commercial opportunity for excipient suppliers?

Excipient suppliers can create value in BYFAVO-related programs by supplying more than commodity glycine or mannitol.

The strongest opportunities involve:

• Low-endotoxin, parenteral-grade excipients
• Controlled-particle-size mannitol
• Excipient grades optimized for lyophilization
• Stabilizers for aqueous remimazolam
• Oxygen-control and light-protective packaging
• Low-adsorption syringe materials
• Ready-to-use sterile diluent systems
• Integrated vial and reconstitution devices
• Analytical methods for degradation and particulate monitoring

The supplier with the best commercial position will usually be the one that provides formulation support, scale-up data, regulatory documentation, and a reliable supply chain. Price competition is likely to be intense for basic glycine and mannitol.

How does BYFAVO compare with competing sedation products?

BYFAVO’s excipient strategy supports a specialized injectable product rather than a broad hospital commodity.

Factor	BYFAVO	Midazolam generic	Propofol generic
Dosage form	Lyophilized powder requiring reconstitution	Usually ready-to-use liquid	Ready-to-use emulsion
Preparation burden	Higher than a liquid	Lower	Lower
Reversal agent	Flumazenil	Flumazenil	No specific routine reversal agent
Formulation complexity	Moderate lyophilized system	Generally simple solution	Complex emulsion
Main differentiation	Procedural sedation profile	Cost and familiarity	Rapid onset and established workflow
Excipient opportunity	Ready-to-use and device presentations	Limited	Emulsion and container optimization
Generic substitution pressure	Emerging	High	High

The excipient opportunity is therefore linked to workflow economics. A product that removes reconstitution or reduces waste may compete effectively even if its ingredient cost is higher.

Key Takeaways

• BYFAVO is a 20-mg lyophilized remimazolam besylate injection supplied with glycine and mannitol as its principal excipients.
• The current product requires reconstitution with sterile water to produce a 2.5-mg/mL solution.
• The strongest formulation opportunities are ready-to-use liquid products, prefilled syringes, higher-concentration presentations, and extended in-use stability.
• Glycine and mannitol alone offer limited differentiation because both are established parenteral excipients.
• Patent value is more likely to arise from defined formulation ranges, stability results, lyophilization processes, container systems, or delivery devices.
• BYFAVO’s NCE exclusivity began with its July 2020 FDA approval and was generally expected to run for five years, while patent-based barriers may extend beyond that period.
• Generic entry faces sterile injectable, reconstitution, bioequivalence, Orange Book, and potential Paragraph IV hurdles.
• Commercial opportunity is strongest for products that reduce preparation time and medication waste in high-volume procedural settings.

FAQs

Can BYFAVO be reformulated as a premixed IV bag?

Potentially, but a premixed bag would require demonstration of aqueous stability, container compatibility, sterility, particulate control, dose uniformity, and an appropriate FDA regulatory pathway. The product’s short procedural use period may make a premixed syringe more practical than a large IV bag.

Are glycine and mannitol patentable excipients for remimazolam?

They can form part of a patentable formulation only when combined with a sufficiently specific claim and a defensible technical result. Glycine and mannitol individually are conventional excipients and would rarely provide strong standalone exclusivity.

Would a remimazolam ready-to-use liquid qualify for an ANDA?

The answer depends on whether the proposed product is pharmaceutically equivalent and therapeutically equivalent to the reference listed drug. A materially different dosage form, formulation, concentration, or delivery system may require a 505(b)(2) application instead.

Does BYFAVO have biosimilar competition risk?

No. Remimazolam is a small molecule, so competitors would pursue generic or 505(b)(2) pathways rather than the biosimilar pathway under the Public Health Service Act.

Which BYFAVO presentation has the highest commercial value?

A ready-to-use prefilled syringe has the clearest differentiation because it can reduce reconstitution steps, preparation errors, and workflow time. Its value depends on achieving adequate stability and device compatibility without creating excessive manufacturing cost.

References

1. U.S. Food and Drug Administration. (2024). BYFAVO (remimazolam besylate) prescribing information. FDA.
2. U.S. Food and Drug Administration. (2020, July 1). FDA approves new drug for use in procedural sedation. FDA.
3. U.S. Food and Drug Administration. (n.d.). New chemical entity exclusivity. FDA, Center for Drug Evaluation and Research.
4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA.
5. U.S. Food and Drug Administration. (2017). Guidance for industry: ANDAs for certain highly purified synthetic peptide drug products that refer to listed drugs of recombinant origin. FDA.
6. U.S. Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary. USP.