List of Excipients in Branded Drug VYLEESI

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Cosette Pharmaceuticals Inc	VYLEESI	bremelanotide	0713-0897	GLYCERIN	2033-11-05
Cosette Pharmaceuticals Inc	VYLEESI	bremelanotide	0713-0897	HYDROCHLORIC ACID	2033-11-05
Cosette Pharmaceuticals Inc	VYLEESI	bremelanotide	0713-0897	SODIUM HYDROXIDE	2033-11-05
Cosette Pharmaceuticals Inc	VYLEESI	bremelanotide	0713-0897	WATER	2033-11-05
AMAG Pharmaceuticals Inc	VYLEESI	bremelanotide	64011-701	GLYCERIN	2033-11-05

VYLEESI Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: August 8, 2026

VYLEESI is a preservative-free, single-dose subcutaneous injection of bremelanotide for acquired, generalized hypoactive sexual desire disorder in premenopausal women. Its excipient system is commercially simple: mannitol in water for injection, with hydrochloric acid and sodium hydroxide used for pH adjustment. The larger commercial opportunity is not a novel excipient itself. It is the development of a stable bremelanotide formulation, alternative delivery device, or lower-cost presentation that can satisfy FDA requirements for a complex peptide injection and device combination.

The principal opportunities are:

• A 505(b)(2) or abbreviated pathway product using the same active ingredient but a differentiated formulation or delivery system.
• A lower-cost prefilled syringe, vial, or alternative autoinjector.
• Improved peptide stability during refrigerated storage and temperature excursions.
• A less painful or easier-to-use subcutaneous presentation.
• Regional licensing and manufacturing of bremelanotide drug product.
• Excipient and container-closure optimization to reduce aggregation, adsorption, particulates, and device losses.

What is the VYLEESI formulation and which excipients does it contain?

VYLEESI contains bremelanotide acetate as the active pharmaceutical ingredient and is supplied in a single-dose autoinjector. Each device delivers 1.75 mg of bremelanotide in 0.3 mL of solution. The product is administered subcutaneously in the abdomen or thigh at least 45 minutes before anticipated sexual activity. The label limits use to one dose in 24 hours and eight doses per month. [1]

Attribute	VYLEESI profile
Active ingredient	Bremelanotide acetate
Delivered dose	1.75 mg
Injection volume	0.3 mL
Route	Subcutaneous
Presentation	Single-dose autoinjector
Preservative	No preservative listed
Primary excipient	Mannitol
Other formulation components	Water for injection; hydrochloric acid and sodium hydroxide for pH adjustment
Storage	Refrigerated before dispensing; product can be kept at room temperature for a limited period under the prescribing information
FDA approval	June 21, 2019
Approved population	Premenopausal women with acquired, generalized HSDD

Mannitol likely provides isotonicity and can affect the physical environment of the peptide during storage. It is not a strong product differentiator because it is widely available, inexpensive, pharmacopeial, and used in injectable products.

The strategic formulation burden sits elsewhere. Bremelanotide is a synthetic cyclic heptapeptide. Development teams must control peptide oxidation, deamidation, aggregation, adsorption to product-contact surfaces, particulate formation, and chemical change during shipping and storage. The formulation must also remain compatible with the autoinjector, syringe barrel, stopper, needle, and adhesive or device materials.

How does the VYLEESI excipient system affect generic and follow-on opportunities?

The excipient system creates a relatively low barrier to composition replication but does not eliminate the technical burden of developing a substitutable product.

A competitor could initially evaluate the following design space:

Formulation variable	Potential commercial purpose	Key development issue
Mannitol concentration	Osmolality and peptide stability control	Must preserve tolerability and stability
Alternative tonicity agent	Differentiate formulation or reduce crystallization risk	Requires comparative stability and safety data
Buffer system	Control pH drift	Buffer species can affect peptide degradation
Surfactant	Reduce adsorption or aggregation	May create injection, immunogenicity, or regulatory concerns
Antioxidant or chelator	Reduce oxidative degradation	Must justify safety and compatibility
Alternative pH	Improve chemical stability or injection tolerability	May affect solubility and local tolerability
Increased concentration	Reduce injection volume	Can increase viscosity, aggregation, or injection force
Preservative-free multidose system	Improve convenience and reduce packaging cost	Requires multidose sterility and in-use stability data

The commercial value of an alternative excipient system depends on whether it produces a measurable advantage. A formulation that merely replaces mannitol with another standard tonicity agent is unlikely to support premium pricing unless it improves shelf life, injection comfort, temperature stability, device performance, or dosing convenience.

The strongest opportunities are likely to involve a combined formulation-device change rather than an excipient substitution alone.

What formulation patents and method-of-use rights may protect VYLEESI?

VYLEESI protection can arise from several separate rights:

1. The bremelanotide molecule and peptide sequence.
2. Pharmaceutical compositions containing bremelanotide.
3. Specific concentration, pH, excipient, or stability ranges.
4. Delivery through an autoinjector or other injection system.
5. Treatment of female sexual dysfunction or HSDD.
6. Dosing schedules, including administration before anticipated sexual activity.
7. Manufacturing and purification processes.

The original molecule is not a new chemical entity in the conventional sense. Palatin developed bremelanotide as a melanocortin receptor agonist, and the commercial value of the VYLEESI estate therefore depends heavily on formulation, delivery, method-of-use, and regulatory exclusivity rights.

The existence of a patent covering a bremelanotide composition does not establish that every mannitol-containing formulation is blocked. A freedom-to-operate review must compare:

• The claimed bremelanotide concentration.
• The claimed pH range.
• The presence and amount of mannitol or another excipient.
• The claimed dosage form.
• The claimed device.
• The claimed therapeutic indication and dosing regimen.
• Patent term adjustment, patent term extension, terminal disclaimers, and family-member status.

Public FDA materials should be used to identify patents listed for the approved product. Patent-family review should then determine whether claims are directed to the marketed formulation, the autoinjector, treatment methods, or broader bremelanotide compositions. The Orange Book remains the controlling source for FDA-listed patents and regulatory exclusivity associated with the NDA. [2]

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

FDA approved VYLEESI under NDA 210557 on June 21, 2019. The product is a drug-device combination because the approved presentation uses a single-dose autoinjector. [1, 3]

The FDA approval established:

• A specific peptide drug substance.
• A sterile injectable drug product.
• A single-dose autoinjector presentation.
• A defined patient population.
• A dose and administration schedule.
• Labeling for acquired, generalized HSDD in premenopausal women.

The original five-year New Chemical Entity exclusivity period would have run from the 2019 approval date, ending in June 2024, subject to the scope of the active ingredient qualification and FDA regulatory records. Any remaining commercial protection must therefore be assessed primarily through patents, device rights, formulation rights, regulatory exclusivities, and market execution.

An ANDA applicant would need to address whether it can demonstrate pharmaceutical equivalence and bioequivalence to the reference product. The autoinjector creates additional complexity. A company may instead consider a 505(b)(2) strategy if it proposes a different device, formulation, strength, concentration, or administration system while relying partly on FDA findings for bremelanotide.

When does VYLEESI lose exclusivity and when could generic entry occur?

VYLEESI’s practical loss of exclusivity is unlikely to be determined by the NCE date alone. It will depend on the latest enforceable patent claims, any pediatric exclusivity, litigation outcomes, settlement terms, and the regulatory pathway selected by a challenger.

Protection category	Strategic relevance
NCE exclusivity	Original five-year period associated with the 2019 approval
Orange Book patents	May delay approval of an ANDA through patent certification and litigation
Formulation patents	Could target peptide stability, concentration, pH, or excipient composition
Device patents	Could cover the autoinjector or drug-device integration
Method-of-use patents	Could cover HSDD treatment, dosing timing, or patient selection
Regulatory exclusivity	Depends on FDA designation and applicable exclusivity period
Trade secrets	May cover manufacturing, filling, inspection, and device assembly

A Paragraph IV certification could trigger patent litigation if an ANDA applicant alleges that listed patents are invalid, unenforceable, or not infringed. The commercial value of such a challenge would depend on the size of the VYLEESI market, the number of potential entrants, and whether the challenger can avoid the device claims through a different presentation.

A generic using a vial or prefilled syringe might face a different patent profile from a product using an autoinjector. A 505(b)(2) applicant could have more flexibility but may face additional clinical, device, or human-factors requirements.

What commercial opportunities exist for VYLEESI excipient suppliers?

The direct excipient opportunity is modest because mannitol is a commodity material. The higher-value opportunities are formulation-development and manufacturing services.

Stabilization and analytical services

Specialty suppliers can support:

• Peptide aggregation screening.
• Oxidation and deamidation control.
• Extractables and leachables studies.
• Container-closure compatibility.
• Low-temperature and accelerated stability programs.
• Subvisible particle testing.
• Device-delivery loss studies.
• Forced-degradation method development.

These services can create recurring revenue during formulation selection, scale-up, and post-approval change management.

Alternative excipient platforms

Potential platforms include low-level nonionic surfactants, amino-acid stabilizers, polyols, buffer systems, and antioxidant strategies. Any platform must preserve:

• Sterility.
• Peptide potency.
• Injection-site tolerability.
• Device compatibility.
• Low particulate burden.
• Acceptable viscosity and injection force.
• Shelf life under labeled storage conditions.

An alternative excipient becomes commercially defensible when it is linked to a patentable composition or a validated product advantage.

Contract manufacturing

Bremelanotide drug product requires sterile peptide handling, aseptic filling, inspection, and device assembly. Contract development and manufacturing organizations can compete on:

• Small-batch commercial production.
• Prefilled or cartridge-based presentations.
• Autoinjector assembly.
• Cold-chain management.
• Process analytical technology.
• Low-volume specialty pharmaceutical economics.

For a product with a targeted indication, manufacturing cost control is important. A lower-cost device and simpler supply chain could improve gross margin even without major clinical differentiation.

How strong is the VYLEESI patent estate?

The estate is strategically mixed.

Estate component	Relative strength
Peptide and active ingredient	Limited by age of the molecule and prior-art exposure
Formulation	Potentially stronger if claims cover narrow stability or concentration ranges
Autoinjector	Potentially meaningful if device claims are difficult to design around
Method of use	Commercially useful but vulnerable to non-infringing-label strategies
Manufacturing	Can protect process know-how, but trade-secret enforcement may be preferable
Excipient composition	Strong only if claims are narrow, enabled, and technically differentiated

The most credible barriers are likely to be the integrated product: sterile peptide formulation, validated container closure, and autoinjector presentation. A competitor that changes only the excipient may still face equivalent-product, device, and method-of-use issues.

Patent strength should be assessed claim by claim rather than by patent count. Important indicators include continuation activity, successful claim prosecution, surviving independent claims, terminal disclaimers, patent-term adjustment, inter partes review exposure, and whether the claims read on the marketed product.

Which companies are relevant to VYLEESI licensing and competition?

Palatin Technologies developed bremelanotide and licensed North American commercial rights to AMAG Pharmaceuticals. AMAG was later acquired by Covis Pharma. VYLEESI commercial rights subsequently moved through later ownership transactions, including a transaction involving Cosette Pharmaceuticals. [4-6]

The competitive field includes:

• Branded VYLEESI.
• Addyi, or flibanserin, an oral treatment for premenopausal women with acquired, generalized HSDD.
• Potential bremelanotide follow-on products.
• Telehealth and specialty-pharmacy distributors.
• Manufacturers of sterile peptide injectables and autoinjectors.
• Future products targeting female sexual dysfunction through hormonal, neurologic, or behavioral mechanisms.

VYLEESI differs from Addyi in route, dosing pattern, and adverse-effect profile. VYLEESI is administered as needed but requires injection and carries nausea and blood-pressure warnings. Addyi is taken daily and has central nervous system and alcohol-related restrictions. These differences create commercial space for a product that improves convenience, tolerability, or adherence rather than simply reproducing the existing formulation.

What generic launch scenarios exist for VYLEESI?

Three launch scenarios are commercially plausible.

Autoinjector-equivalent ANDA

This route would seek a product closely matching the reference drug product and device. It may offer the clearest substitution pathway but creates the highest device-equivalence burden.

Alternative presentation

A prefilled syringe, vial, cartridge, or different autoinjector could reduce device cost or improve usability. This approach may fit a 505(b)(2) strategy and could avoid some device claims, but it may require additional human-factors and clinical evidence.

Reformulated bremelanotide product

A longer-stability, lower-volume, or temperature-tolerant formulation could seek differentiation. The commercial value would depend on whether the improvement supports a new label, pricing premium, or licensing position.

What geographic opportunities exist?

North American rights were historically separated from broader Palatin rights through licensing arrangements. Geographic opportunities should be evaluated independently because patent term, regulatory approval, reimbursement, and sexual-health prescribing practices differ by country.

Priority markets may include:

• United States, because of the established FDA label and specialty-pharmacy infrastructure.
• European markets, subject to separate regulatory requirements and commercial positioning.
• Japan and other advanced pharmaceutical markets with demand for women’s health products.
• Selected emerging markets where cold-chain and autoinjector costs may favor a vial or prefilled syringe.

The most attractive regional strategy may be a local-license model combining peptide drug substance, a simplified presentation, and specialty distribution.

Key Takeaways

• VYLEESI uses a simple excipient system centered on mannitol, water for injection, and pH adjustment agents.
• Mannitol itself is unlikely to provide a durable commercial moat.
• The principal technical barriers are peptide stability, sterile manufacturing, container compatibility, and autoinjector performance.
• The original FDA NCE exclusivity period began in 2019 and would generally have expired in 2024.
• Remaining protection depends on Orange Book patents, formulation and device claims, method-of-use rights, and litigation or settlement outcomes.
• A 505(b)(2) product using a different device or improved formulation may be more commercially practical than a direct autoinjector-equivalent generic.
• The strongest excipient opportunity is a validated stability or tolerability improvement that supports patent protection or a differentiated label.
• Commercial competition includes Addyi, future bremelanotide entrants, specialty pharmacies, telehealth platforms, and sterile peptide manufacturers.
• Low-volume, low-cost manufacturing and device assembly may offer more value than commodity excipient supply.

FAQs About VYLEESI Excipient and Commercial Strategy

Is VYLEESI preservative-free?

Yes. The approved single-dose autoinjector formulation does not list a preservative. Its inactive ingredients include mannitol, water for injection, and agents used to adjust pH. [1]

Could a company replace mannitol in a VYLEESI follow-on product?

Potentially, but the replacement would require compatibility, stability, sterility, safety, and regulatory data. Replacing mannitol alone would not necessarily create meaningful market differentiation.

Is VYLEESI eligible for an ordinary generic drug application?

A conventional ANDA may be difficult because the reference product is a peptide injection supplied in an autoinjector. The applicant would need to evaluate pharmaceutical equivalence, device sameness or substitutability, bioequivalence, and listed patent barriers.

Does VYLEESI have biosimilar risk?

No traditional biosimilar pathway applies because bremelanotide is a synthetic peptide drug rather than a biologic licensed under the Public Health Service Act. Follow-on competition would more likely use an ANDA, 505(b)(2), or another applicable drug pathway.

What is the best commercial differentiation strategy for a VYLEESI competitor?

The strongest strategy is likely an integrated formulation-device improvement, such as lower injection volume, improved temperature stability, reduced injection force, longer shelf life, or a simpler presentation. An isolated excipient substitution is less likely to justify premium pricing.

References

1. U.S. Food and Drug Administration. (2019). VYLEESI (bremelanotide injection) prescribing information.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Food and Drug Administration. (2019, June 21). FDA approves new treatment for hypoactive sexual desire disorder in premenopausal women.
4. Palatin Technologies, Inc. (2017). Annual report and disclosures regarding the license agreement for bremelanotide with AMAG Pharmaceuticals.
5. AMAG Pharmaceuticals, Inc. (2020). Corporate transaction disclosures regarding the acquisition by Covis Pharma.
6. Cosette Pharmaceuticals. (2021-2022). Corporate announcements regarding VYLEESI commercial rights.