List of Excipients in Branded Drug MUSE

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Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Meda Pharmaceuticals Inc	MUSE	alprostadil	0037-8110	POLYETHYLENE GLYCOL 1450

MUSE Excipient Strategy, Formulation Patents, and Commercial Opportunities

Last updated: September 27, 2026

MUSE is an alprostadil urethral suppository for erectile dysfunction. Its formulation uses polyethylene glycol 1450 as the primary excipient in a single-use urethral delivery system. The product’s principal commercial opportunity is no longer basic composition-of-matter protection. It is reformulation, device optimization, geographic expansion, and lower-cost generic or branded-generic supply.

MUSE has a relatively low-complexity excipient profile but a high product-performance burden. Any substitute must preserve rapid dissolution, urethral tolerability, dose uniformity, applicator compatibility, and alprostadil stability. The product’s long market history means that formulation differentiation and regulatory execution are more commercially relevant than broad patent exclusivity.

What is MUSE and how is it administered?

MUSE contains alprostadil, also known as prostaglandin E1, in a medicated urethral suppository. The FDA-approved strengths are 125 micrograms, 250 micrograms, 500 micrograms, and 1,000 micrograms [1].

The system uses a single-use applicator that deposits the suppository into the urethra. Alprostadil is absorbed through the urethral mucosa and produces vasodilation that supports penile erection. MUSE avoids oral absorption and injection but requires a specialized administration technique.

Product characteristic	MUSE profile
Active ingredient	Alprostadil, prostaglandin E1
Dosage form	Urethral suppository
Strengths	125, 250, 500, and 1,000 micrograms
Route	Intraurethral
Primary excipient	Polyethylene glycol 1450
Delivery system	Single-use urethral applicator
Therapeutic area	Erectile dysfunction
Regulatory pathway	FDA-approved new drug application
Reference product	MUSE, NDA 020379
Biosimilar relevance	None; MUSE is a small-molecule drug
Generic pathway	Potential ANDA pathway, subject to current FDA requirements and listed patent status

The FDA label identifies polyethylene glycol 1450 as the inactive ingredient. The product is designed to dissolve after insertion rather than remain as a conventional solid dosage form in the urethra [1].

What excipient does MUSE use?

MUSE uses polyethylene glycol 1450, commonly abbreviated PEG 1450, as its primary excipient. PEG 1450 is a water-soluble, low-molecular-weight polyethylene glycol with melting and dissolution properties suitable for a small urethral dosage form.

Its formulation functions include:

• forming the suppository matrix;
• dispersing a low-dose quantity of alprostadil;
• permitting rapid dissolution in urethral moisture;
• supporting manufacturing of small, dose-specific pellets;
• maintaining compatibility with the applicator and packaging system.

PEG 1450 is commercially available from multiple pharmaceutical excipient suppliers. That reduces supply-chain exclusivity risk but also limits differentiation based solely on raw-material sourcing.

Why PEG 1450 is technically important

The MUSE dose is small relative to the excipient matrix. That creates a dose-uniformity challenge, particularly at the 125-microgram and 250-microgram strengths. The formulation must control:

• alprostadil dispersion throughout the PEG matrix;
• assay and content uniformity;
• pellet dimensions and mass;
• melting or softening during processing;
• moisture uptake;
• oxidation and degradation;
• extraction or migration from packaging;
• mechanical integrity during applicator loading.

Alprostadil is susceptible to degradation under certain environmental conditions. Manufacturing and packaging controls therefore have material importance even though the excipient system is simple. A new excipient platform that improves stability could have greater commercial value than one that merely reduces ingredient cost.

What excipient alternatives could replace PEG 1450 in MUSE?

Several excipient classes could support a MUSE-like product, but each would require formulation and clinical assessment. The most commercially credible alternatives are listed below.

Excipient or platform	Potential benefit	Principal development risk
PEG grades with different molecular weights	Adjusts dissolution, mechanical properties, and processing behavior	May change release rate, irritation, and dose uniformity
PEG blends	Allows tuning of melting point and hardness	Greater process complexity and potential lot variability
Povidone or copovidone	Water solubility and film-forming properties	Hygroscopicity and altered mucosal residence
Polyoxamers	Wetting and solubilization support	Possible changes in drug partitioning and local tolerability
Hydroxypropyl methylcellulose	Mucoadhesion and controlled hydration	May slow dissolution beyond the desired onset
Polycarbophil or carbomer systems	Longer mucosal residence	Increased irritation, swelling, and residual-mass risk
Lipid or wax matrices	Improved handling and possible sustained release	Poorer water dissolution and more complex stability profile
Cyclodextrin-containing systems	Potential alprostadil solubilization	Added regulatory complexity and excipient qualification
Low-molecular-weight hydrophilic polymer blends	Tailored dissolution and manufacturability	Need to establish equivalence to the reference product

A direct replacement of PEG 1450 is unlikely to produce a commercially acceptable product without changes to the applicator, release profile, and clinical instructions. MUSE’s value is created by the combination of drug, matrix, dimensions, applicator, and administration method.

What formulation strategy offers the strongest commercial opportunity?

The strongest opportunities are reformulations that improve one of four measurable attributes: onset, tolerability, convenience, or stability.

Faster-dissolving formulation

A lower-viscosity or more rapidly hydrating matrix could reduce the time required for dissolution. The commercial benefit would be limited unless the improvement produces a clinically meaningful reduction in time to erection or improves patient adherence.

Lower-irritation formulation

Urethral pain and burning are recognized limitations of intraurethral alprostadil. A formulation that reduces local irritation could compete with the existing product even if its pharmacodynamic effect is similar. Candidate approaches include:

• reducing local drug concentration spikes;
• using a more rapidly dispersing matrix;
• adjusting pH and osmolality;
• incorporating a validated mucosal lubricant;
• modifying pellet geometry;
• controlling the surface area exposed immediately after insertion.

A local anesthetic or other active tolerability modifier would create a substantially more complex regulatory program and could affect safety, sensation, and sexual function.

Improved stability formulation

A higher-stability product could reduce cold-chain or moisture-control requirements, extend shelf life, and lower wastage. Commercial development should evaluate:

• oxygen exposure;
• moisture transmission;
• light protection;
• antioxidant compatibility;
• container-closure integrity;
• applicator polymer interaction;
• stability after warehouse temperature excursions.

Improved stability is particularly attractive for international markets with challenging distribution conditions.

Higher-convenience delivery system

The applicator is part of MUSE’s product profile. A shorter, more discreet, easier-to-grip, or more intuitive device could address administration barriers without changing the active ingredient. Device changes may require human-factors validation and could create a separate patent position.

Combination or co-delivery system

A co-formulated vasodilator, lubricant, or absorption enhancer could increase efficacy or reduce dose. This route has the highest potential differentiation but also the greatest clinical and regulatory risk. A new active ingredient would generally require a new drug development strategy rather than a simple generic or reformulation pathway.

What patents protect MUSE and when does MUSE lose exclusivity?

MUSE’s early formulation and urethral-delivery patent estate is old relative to the product’s launch. The core product was approved in the 1990s, and the principal commercial opportunity has moved beyond original formulation exclusivity.

Exclusivity category	MUSE assessment
Alprostadil active ingredient	Long expired
Original urethral delivery concepts	Early patents generally expired based on ordinary statutory terms
PEG-based suppository formulation	Early patent protection is not a durable current barrier
Applicator design	Protection depends on individual patent claims and jurisdiction
Method-of-use patents	Any surviving claims would require current patent-database review
FDA regulatory exclusivity	Original approval exclusivity has expired
Current generic risk	High from an exclusivity perspective, subject to product-specific FDA requirements

A precise current Orange Book conclusion depends on the live listing for NDA 020379 and any later supplements. The commercial conclusion is clear: MUSE does not have the profile of a recently launched product protected by a long remaining exclusivity period.

What is the Orange Book status of MUSE?

MUSE is associated with FDA NDA 020379. The Orange Book is the relevant FDA source for determining whether the reference product has listed patents or exclusivity that could affect an ANDA applicant [2].

For a generic applicant, the key questions are:

1. whether the reference product remains listed as a prescription drug;
2. whether any patents are currently listed;
3. whether listed patents cover the drug, formulation, method of use, or delivery system;
4. whether the proposed ANDA must include a Paragraph IV certification;
5. whether the applicant can design around any listed claims;
6. whether the reference product’s labeling and dosage-form requirements create additional bioequivalence work.

Because MUSE is a locally administered urethral dosage form, an ANDA applicant may face more complex equivalence questions than an ordinary oral tablet. The FDA may focus on product quality, dose uniformity, release, device performance, and clinical usability rather than relying solely on conventional systemic pharmacokinetic measurements.

What Paragraph IV challenges and generic launch risks exist?

A Paragraph IV challenge would be relevant only if a currently listed patent blocks approval or launch. The fundamental generic opportunity is more likely to arise through a conventional ANDA strategy, an authorized generic arrangement, or a branded-generic relaunch than through litigation over a strong remaining composition patent.

Potential launch scenarios include:

Scenario	Commercial implication
No blocking listed patent	ANDA applicant can pursue approval subject to FDA requirements
Listed formulation patent	Paragraph IV or Paragraph III certification may be required
Device-related patent	Applicant may need a redesigned applicator
Reference shortage or discontinuation	Opportunity for rapid market entry if FDA substitution rules permit
Authorized generic	Lower litigation risk but potentially lower margin
505(b)(2) reformulation	Useful for a differentiated excipient or device product
Branded reformulation	Preserves pricing power but requires clinical and commercial investment

The main generic risks are not likely to be basic alprostadil patent rights. They are manufacturing reproducibility, low-dose content uniformity, urethral tolerability, device reliability, and FDA expectations for locally acting products.

What FDA regulatory pathway applies to an improved MUSE formulation?

The regulatory pathway depends on the degree of change.

ANDA

An ANDA is the most efficient route for a product that can demonstrate sameness or acceptable equivalence to the reference product. A change in inactive ingredients may still be possible, but the applicant must establish that the change does not alter safety, efficacy, performance, or bioequivalence.

505(b)(2) application

A 505(b)(2) application is more suitable for:

• a new excipient system;
• a modified applicator;
• a new strength or dosing regimen;
• an altered release profile;
• a new indication;
• a clinically meaningful change in tolerability or onset.

The applicant may rely partly on FDA findings for MUSE while providing new nonclinical, clinical, and CMC data for the changed formulation.

Supplemental NDA

The current sponsor could pursue formulation, manufacturing, packaging, or device changes through a supplemental NDA when the product remains sufficiently within the approved product framework.

For a new excipient in a urethral product, FDA scrutiny would likely focus on local safety, mucosal irritation, impurity profile, extractables and leachables, and comparative performance.

How strong is the MUSE patent estate?

The original MUSE patent estate is commercially weak by current pharmaceutical standards because the product and its core technology are mature. The strongest remaining protection would more likely come from narrow claims covering:

• a specific applicator geometry;
• a defined excipient ratio;
• a stability-enhancing package;
• a particular alprostadil particle or dispersion state;
• a dose-uniformity manufacturing process;
• a differentiated combination product;
• a new method of treating erectile dysfunction.

Such claims can support incremental exclusivity but are vulnerable to design-around strategies. A new entrant should avoid copying protected applicator architecture and should build independent evidence around formulation composition, manufacturing controls, and device operation.

Which companies are challenging or competing with MUSE?

MUSE competes with both pharmacologic and nonpharmacologic erectile-dysfunction products.

Competitor	Active or technology	Competitive advantage
Viagra and generic sildenafil	PDE5 inhibitor	Established oral use and low generic cost
Cialis and generic tadalafil	PDE5 inhibitor	Longer duration of action
Levitra/Staxyn and generic vardenafil	PDE5 inhibitor	Oral alternative
Caverject and generic injectable alprostadil	Injectable alprostadil	High efficacy but injection burden
Edex	Injectable alprostadil	Established intracavernosal delivery
Compounded intracavernosal mixtures	Alprostadil combinations	Dose customization, lower consistency
Vacuum erection devices	Mechanical therapy	Drug-free option
Penile implants	Surgical device	Durable efficacy for selected patients

MUSE’s differentiation is needle-free local administration. Its disadvantages are administration complexity, urethral discomfort, variable response, and competition from inexpensive oral generics.

What licensing deals and commercial ownership affect MUSE?

MUSE was developed and commercialized through the Vivus and Meda commercial history. Meda acquired U.S. rights to MUSE from Vivus, and Mylan later acquired Meda. Mylan became part of Viatris in 2020 [3, 4].

Product-specific revenue is not generally disclosed separately in public company reporting. MUSE is therefore more useful as a portfolio, licensing, or niche-commercialization asset than as a transparent standalone revenue opportunity.

Potential transaction structures include:

• regional licensing for markets where intraurethral therapy has limited competition;
• acquisition of branded rights with a low-cost manufacturing strategy;
• authorized-generic supply;
• co-development of a new applicator;
• 505(b)(2) reformulation licensing;
• contract manufacturing of the PEG-alprostadil suppository;
• bundle agreements with urology clinics or specialty pharmacies.

What are the geographic opportunities for MUSE?

The strongest geographic opportunities are markets where:

• injectable alprostadil has limited patient acceptance;
• PDE5 inhibitor use is constrained by contraindications or drug interactions;
• specialty urology channels can support patient training;
• prescription prices support a branded or differentiated product;
• local manufacturing reduces import and distribution cost.

A regional strategy should account for differing requirements for device registration, excipient standards, local clinical evidence, pharmacovigilance, and prescription classification. PEG 1450 is broadly recognized as a pharmaceutical excipient, but local compendial and quality requirements still apply.

What manufacturing and IP barriers affect a new MUSE-like product?

Manufacturing barriers are moderate but execution-sensitive. The main issues are:

• uniform dispersion of microgram-level alprostadil doses;
• controlled pellet formation;
• prevention of drug degradation;
• applicator filling and sealing;
• container-closure integrity;
• low moisture exposure;
• reproducible dissolution;
• supplier qualification for PEG and device polymers.

The most defensible IP position would combine formulation and device claims with process controls that are difficult to replicate. A simple PEG substitution is unlikely to create durable protection. A platform integrating a stabilized alprostadil dispersion, improved mucosal tolerability, and a redesigned applicator would have stronger licensing value.

How does MUSE compare with oral PDE5 inhibitors and injectable alprostadil?

Attribute	MUSE	Oral PDE5 inhibitors	Injectable alprostadil
Administration	Intraurethral	Oral	Intracavernosal injection
Needle-free	Yes	Yes	No
Generic competition	Likely or increasing	Extensive	Present
Onset	Local, generally within minutes	Typically requires lead time	Rapid
Local discomfort	Material risk	Usually lower local burden	Injection pain possible
Systemic interactions	Lower systemic exposure than oral therapy, but not absent	Important drug-interaction profile	Lower systemic exposure, local effects
Device dependence	Yes	No	Syringe/device
Formulation complexity	Moderate	Low for tablets	Moderate
Differentiation opportunity	Excipient, device, stability	Limited	Combination and delivery

MUSE is most commercially attractive where patients reject injections and cannot use or do not respond adequately to oral PDE5 inhibitors.

Key Takeaways

• MUSE is an alprostadil urethral suppository using PEG 1450 as its principal excipient.
• The product has four FDA-approved strengths: 125, 250, 500, and 1,000 micrograms.
• Core MUSE and alprostadil patent protection is mature, making current exclusivity relatively weak.
• The main development opportunities are improved tolerability, faster dissolution, better stability, and a more convenient applicator.
• PEG blends, polyoxamers, povidone systems, mucoadhesive polymers, and lipid matrices are technically plausible alternatives, but each changes regulatory and clinical risk.
• A conventional ANDA may be possible for a close generic; a materially changed formulation is more suitable for a 505(b)(2) application.
• MUSE has no biosimilar risk because alprostadil is a small molecule.
• Public company filings generally do not isolate MUSE revenue, limiting standalone valuation precision.
• The strongest commercial strategy is a differentiated formulation-device platform rather than an unmodified PEG-based copy.

FAQs

Can PEG 1450 in MUSE be replaced without new clinical trials?

A replacement may be possible under an ANDA or supplemental NDA if the new formulation demonstrates equivalent quality, performance, safety, and efficacy. A material change in dissolution, local exposure, tolerability, or device performance could require additional clinical evidence.

Is MUSE eligible for a biosimilar application?

No. MUSE contains alprostadil, a chemically synthesized small molecule. The relevant abbreviated pathway is an ANDA, while a materially different product may require a 505(b)(2) application.

What is the most valuable MUSE formulation improvement?

A formulation that reduces urethral discomfort without slowing onset is likely to have the clearest commercial value. Stability improvement and applicator redesign are also attractive because they can improve distribution and adherence.

Can a company launch a generic MUSE with a different applicator?

Potentially. The applicant must demonstrate that the alternative applicator delivers the product reliably and does not create clinically meaningful differences in dose delivery, administration, or safety. Device changes can also create separate regulatory and patent issues.

Does MUSE still have meaningful patent-based pricing power?

The original product has limited remaining exclusivity leverage compared with newer specialty drugs. Pricing power is more likely to come from brand recognition, physician familiarity, distribution access, device convenience, and differentiated tolerability than from broad patent protection.

References

1. U.S. Food and Drug Administration. (n.d.). MUSE (alprostadil) urethral suppository prescribing information.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. Meda AB. (2016). Annual report 2015.
4. Viatris Inc. (2021). Annual report 2020.