List of Excipients in Branded Drug METHOXSALEN

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Oceanside Pharmaceuticals	METHOXSALEN	methoxsalen	68682-065	D&C YELLOW NO. 10
Oceanside Pharmaceuticals	METHOXSALEN	methoxsalen	68682-065	FD&C BLUE NO. 1
Oceanside Pharmaceuticals	METHOXSALEN	methoxsalen	68682-065	FD&C YELLOW NO. 6
Oceanside Pharmaceuticals	METHOXSALEN	methoxsalen	68682-065	GELATIN
Oceanside Pharmaceuticals	METHOXSALEN	methoxsalen	68682-065	GLYCERIN
Oceanside Pharmaceuticals	METHOXSALEN	methoxsalen	68682-065	METHYLPARABEN

Generic Drugs Containing METHOXSALEN

Company	Ingredient	NDC	Excipient
Actavis Pharma Inc	methoxsalen	45963-325	D&C YELLOW NO. 10
Actavis Pharma Inc	methoxsalen	45963-325	FD&C BLUE NO. 1
Actavis Pharma Inc	methoxsalen	45963-325	FD&C RED NO. 40
Actavis Pharma Inc	methoxsalen	45963-325	GELATIN
Actavis Pharma Inc	methoxsalen	45963-325	GLYCERIN
Actavis Pharma Inc	methoxsalen	45963-325	METHYLPARABEN SODIUM

What are the Most Frequently-Used Excipients in METHOXSALEN?

# Of NDCs	Excipient
1	AMMONIA
1	ANHYDROUS CITRIC ACID
1	BUTYL ALCOHOL
2	D&C YELLOW NO. 10
2	FD&C BLUE NO. 1
1	FD&C RED NO. 40

Methoxsalen Excipient Strategy and Commercial Opportunities

Last updated: August 24, 2026

Methoxsalen is an established psoralen used with ultraviolet A exposure and extracorporeal photopheresis. Its commercial value is concentrated in two technically different products: oral capsules and the sterile UVADEX solution used in photopheresis. The main development opportunities are improved solubility, photostability, dose uniformity, sterile manufacturing, packaging, and product-device compatibility rather than new-molecule patenting.

What products contain methoxsalen and how are they regulated?

Methoxsalen products use distinct dosage forms and FDA pathways.

Product or product type	Dosage form	Principal use	Regulatory position	Commercial constraint
UVADEX	Sterile solution, 20 mcg/mL	Adjunct to extracorporeal photopheresis for skin manifestations of cutaneous T-cell lymphoma	FDA-approved prescription product	Requires sterile manufacturing and compatibility with the photopheresis system
Oxsoralen-Ultra	10 mg oral capsule	Psoriasis and other photochemotherapy applications	Historical FDA-approved oral product; commercial availability has been limited	Oral exposure to methoxsalen creates significant photosensitivity-management requirements
Generic oral methoxsalen	Capsule or equivalent oral dosage form	Potential AB-rated substitution where an approved reference product is available	ANDA or other applicable pathway	Bioequivalence and reference-product availability are central risks
New oral, liquid, topical, or device-linked product	Modified dosage form	Potentially improved administration or niche use	Potential 505(b)(2) pathway	Clinical bridging, phototoxicity, CMC, and intellectual-property risk

UVADEX is labeled as methoxsalen 20 mcg/mL in a sterile solution for use with an approved photopheresis system. The product is not a conventional intravenous infusion and is administered as part of an extracorporeal treatment procedure. The FDA label identifies its use in patients with cutaneous T-cell lymphoma who have not responded adequately to other therapy.[1]

Methoxsalen is not a biologic. Biosimilar approval is therefore not relevant. Competition would arise through generic, hybrid, reformulated, or device-linked products.

What excipients are used in methoxsalen products?

The approved oral and sterile products require different excipient strategies because methoxsalen is poorly water soluble and sensitive to light.

Oral capsules

Historical methoxsalen capsule formulations use conventional solid-dose excipients, including lactose-based fillers and disintegrant or lubricant systems, depending on the manufacturer and formulation version. The relevant formulation objectives are:

• consistent dissolution across the gastrointestinal tract;
• uniform methoxsalen distribution at low milligram strength;
• protection from light during manufacture and storage;
• acceptable capsule fill weight;
• control of content uniformity;
• avoidance of excipients that materially alter absorption.

For a generic oral capsule, a formulation that uses the same inactive ingredients as the reference product can reduce regulatory friction. A different excipient system may still be acceptable, but it increases the need to demonstrate comparable dissolution, bioequivalence, and absence of clinically meaningful absorption effects.

Methoxsalen is administered before UVA exposure. Changes in dissolution or systemic exposure can alter the timing and intensity of photosensitivity. Excipients that produce rapid release, delayed release, or food-sensitive absorption should therefore be treated as clinically relevant rather than cosmetic formulation changes.

UVADEX sterile solution

The UVADEX product is a low-concentration sterile solution intended for extracorporeal use. The formulation must maintain methoxsalen in solution at approximately 20 mcg/mL while meeting requirements for sterility, particulate control, extractables, leachables, container closure integrity, and photoprotection.

The principal commercial formulation questions are:

1. Which cosolvent system provides sufficient solubility without compromising hemocompatibility?
2. Does the formulation remain stable during storage and during the photopheresis procedure?
3. Does the solution adsorb to tubing, chamber surfaces, or other system components?
4. Does the container protect methoxsalen from ultraviolet and visible light?
5. Can the product be manufactured aseptically at economically viable batch sizes?

The product label identifies alcohol and other solution excipients in the formulation. Exact inactive-ingredient composition should be taken from the current FDA-approved prescribing information and product package because formulation and labeling records can change.[1]

Which excipient technologies create the strongest commercial opportunities?

The most attractive opportunities are platform technologies that solve a measurable product problem without requiring a new therapeutic indication.

Solubility-enhancing systems

Methoxsalen has limited aqueous solubility. Candidate approaches include:

• ethanol or other pharmaceutically acceptable cosolvents;
• propylene glycol-type cosolvent systems;
• cyclodextrin complexes;
• surfactant-assisted solutions;
• amorphous solid dispersions;
• lipid-based oral systems;
• nanosized or particle-engineered suspensions.

For oral capsules, a solubility-enhancing excipient can improve dissolution but may also change exposure. The commercial value is highest when the technology improves batch reproducibility or reduces food effects without increasing phototoxicity.

For sterile products, the excipient must be suitable for parenteral or extracorporeal exposure and compatible with blood-contacting materials. A formulation that performs well in a standard vial may fail after contact with the photopheresis circuit.

Photostabilizing systems

Methoxsalen is intentionally activated by UVA, which creates a difficult formulation balance. The product must resist premature photodegradation during manufacturing, storage, dispensing, and handling while remaining pharmacologically active during controlled treatment.

Commercially relevant measures include:

• amber or ultraviolet-blocking primary containers;
• secondary foil overwraps;
• low-light manufacturing procedures;
• oxygen-control strategies;
• validated light-exposure limits;
• packaging with visible-use instructions;
• photostability-indicating analytical methods.

A packaging innovation may be more commercially practical than a new excipient because it can reduce degradation without introducing a new safety assessment for systemic exposure.

Low-adsorption and device-compatible formulations

For UVADEX or a competing extracorporeal product, device compatibility is a major barrier. Methoxsalen can potentially interact with plastics, elastomers, tubing, filters, or treatment chambers. A formulation developer should evaluate:

• recovery of methoxsalen after circulation through the full system;
• adsorption to polymeric surfaces;
• concentration changes during treatment;
• extractables and leachables;
• precipitation or haze;
• filter retention;
• impact of flow rate and temperature;
• compatibility with sterilization and storage conditions.

A product that is chemically equivalent but performs differently in the photopheresis circuit may face regulatory and commercial resistance from treatment centers.

Dose-uniformity technologies

Oral methoxsalen is administered at a low absolute dose relative to many conventional drugs. Content uniformity is therefore important. Improvements may come from:

• ordered mixing;
• carrier-based blending;
• spray-dried drug-excipient particles;
• liquid-filled hard capsules;
• multiparticulate systems;
• in-process near-infrared testing.

These technologies can support a formulation patent if the product has a defined composition, process, and measurable performance advantage. A broad claim covering routine capsule excipients would face a high invalidity risk.

What patents protect methoxsalen formulations?

The original methoxsalen compound and early psoralen photochemotherapy patents are old. The commercial patent opportunity is therefore concentrated in later formulation, packaging, manufacturing, and treatment-system claims.

Patent category	Likely claim subject	Strategic value
Composition of matter	Methoxsalen molecule or basic salts	Low for new U.S. exclusivity; historical rights are generally old
Oral formulation	Solubility enhancement, dissolution control, capsule composition	Moderate if supported by unexpected pharmacokinetic or stability data
Sterile solution	Cosolvent ratio, concentration, pH, sterility, container system	Moderate to high if tied to stability and device performance
Photostable packaging	Light-blocking vial, ampoule, overwrap, dispensing system	Moderate; useful as a lifecycle patent
Manufacturing process	Aseptic preparation, low-light processing, impurity control	Moderate, particularly where process impurities are difficult to reproduce
Treatment method	Methoxsalen dosing with UVA or photopheresis	Limited where method is old or broadly described
Device combination	Methoxsalen formulation used with a defined photopheresis circuit	Potentially significant, but depends on claim scope and device ownership

A patent directed only to the presence of a familiar cosolvent is vulnerable to obviousness and routine-optimization arguments. A stronger patent position would link the excipient system to a quantified technical result, such as:

• reduced methoxsalen loss in the photopheresis circuit;
• improved stability under defined light exposure;
• reduced precipitation at refrigerated conditions;
• improved dissolution without increased peak exposure;
• lower extractables from the treatment system;
• improved sterility assurance or container closure performance.

The FDA Orange Book remains the primary source for current listed patents and regulatory exclusivities for approved drug products.[2] Methoxsalen’s active pharmaceutical ingredient is not eligible for biosimilar protection because it is a small molecule. The relevant U.S. competition questions are generic substitution, 505(b)(2) reformulation, and product-device differentiation.

When does methoxsalen lose exclusivity?

Methoxsalen’s original molecule-level exclusivity has long expired. The principal commercial exclusivity risks now arise from product-specific patents, regulatory exclusivity, manufacturing know-how, and control of the photopheresis platform.

Exclusivity type	Methoxsalen relevance
New chemical entity exclusivity	Not available for the old active ingredient
Five-year NCE period	Expired
Three-year clinical-investigation exclusivity	Possible only for a qualifying new approval supported by new clinical studies
Pediatric exclusivity	Product-specific and dependent on FDA action
Orphan-drug exclusivity	Relevant only if a qualifying orphan indication and approval exist
Listed formulation or method patents	Must be assessed by product and current Orange Book listing
Trade secrets	Potentially important for sterile processing, impurity control, and device compatibility

A reformulated methoxsalen product could seek three-year exclusivity if approval relies on new clinical investigations essential to approval. That protection would not block an ANDA referencing the older product unless the statutory requirements and scope of the exclusivity apply. A new formulation also would not recreate molecule-level exclusivity.

What generic entry risks exist for methoxsalen?

Oral generic entry

The oral product presents the clearest conventional generic opportunity. A potential ANDA sponsor would need to address:

• reference-listed drug availability;
• pharmaceutical equivalence;
• bioequivalence;
• dissolution across relevant media;
• capsule content uniformity;
• photostability;
• labeling for UVA-associated photosensitivity;
• manufacturing controls for a low-dose active.

If the branded reference product is discontinued or difficult to source, an applicant may face a reference-product problem. FDA regulatory status, not simply historical approval, determines whether an ANDA route is practical.

Sterile solution entry

A competing UVADEX-type product faces greater technical and commercial barriers. The sponsor would need to establish:

• sterile solution equivalence;
• concentration and route compatibility;
• container closure integrity;
• photostability;
• extractables and leachables;
• stability after opening or preparation;
• compatibility with the photopheresis device;
• clinical or analytical comparability as required by FDA.

Because treatment centers are organized around specific photopheresis systems, a generic solution may need more than a chemically equivalent formulation. The supplier may also need commercial agreements with device operators, distributors, and specialized treatment centers.

505(b)(2) reformulation

A 505(b)(2) product could pursue a new delivery system, concentration, route, or excipient platform. Possible targets include:

• a more stable sterile solution;
• a ready-to-use treatment product;
• a modified oral capsule;
• a liquid oral formulation;
• a photoprotected unit-dose package;
• a formulation designed for a specific extracorporeal circuit.

The pathway is commercially attractive only if the product solves a clear operational or clinical problem. A minor excipient substitution without a meaningful benefit would face weak differentiation and limited pricing power.

Which companies are positioned in the methoxsalen market?

The established product and procedure market is associated with the UVADEX brand and the THERAKOS photopheresis platform. The market is specialized and depends on hematology, oncology, dermatology, transplant, and immune-mediated disease treatment centers.

Potential competitor groups include:

1. generic-drug manufacturers targeting oral methoxsalen;
2. sterile injectable manufacturers with low-volume aseptic capabilities;
3. specialty pharmaceutical companies focused on phototherapy;
4. excipient and drug-delivery companies with cyclodextrin, lipid, or amorphous-dispersion platforms;
5. photopheresis-device companies seeking formulation control;
6. contract development and manufacturing organizations with sterile fill-finish capacity.

Licensing opportunities are strongest where the excipient owner has a validated platform and the methoxsalen sponsor controls regulatory development, photopheresis distribution, or clinical access. A simple excipient supply agreement is less defensible than a package involving formulation know-how, analytical methods, regulatory support, and manufacturing transfer.

How strong is the methoxsalen patent estate?

Methoxsalen has a weak legacy composition-of-matter position but can support targeted lifecycle protection.

Asset type	Patent strength	Reason
Old active ingredient	Low	Long-established small molecule
Conventional oral capsule	Low to moderate	Routine excipients are vulnerable to obviousness challenges
Novel solubility system	Moderate	Stronger if pharmacokinetic or stability benefits are unexpected
Photostable container	Moderate	Claims can be narrow but commercially useful
Device-compatible sterile formulation	Moderate to high	Technical data can establish a meaningful product distinction
Manufacturing impurity-control process	Moderate	Trade-secret protection may be more important than patent scope
Broad method-of-use claim	Low	Photochemotherapy and photopheresis uses are established
Narrow dosing or procedural method	Moderate	Value depends on clinical evidence and enforceability

The best defensible estate would combine composition claims, container claims, manufacturing claims, and narrow method claims. Relying on a single formulation patent would leave the product exposed to design-around strategies.

What commercial opportunities exist in methoxsalen excipients?

Premium sterile formulation

A stabilized, low-adsorption sterile solution could command value if it extends shelf life, reduces waste, improves treatment preparation, or supports more reliable photopheresis dosing. The target customer is the treatment center rather than the individual patient.

Photoprotective packaging

A low-cost package redesign could address light exposure during pharmacy storage, transport, and treatment preparation. This opportunity is easier to implement than a new excipient because it may avoid changes to systemic exposure.

Oral bioavailability control

A formulation that reduces food effects or improves dose consistency could support a 505(b)(2) product. The development burden is higher because changes in exposure may affect UVA treatment safety.

Regional manufacturing and supply resilience

Methoxsalen is a niche product with specialized supply requirements. A second-source sterile manufacturer could create value through:

• domestic fill-finish;
• dual sourcing of critical excipients;
• validated low-volume batches;
• improved inventory availability;
• regional distribution;
• backup container-closure suppliers.

Combination with photopheresis systems

A formulation specifically validated for a photopheresis circuit could create switching costs and a stronger commercial position. The relevant intellectual property would likely involve the formulation, treatment method, and system interface rather than methoxsalen alone.

What litigation and settlement issues affect methoxsalen?

The principal litigation risks are likely to arise from:

• Paragraph IV challenges to listed formulation or method patents;
• patent disputes involving photopheresis systems;
• product liability claims related to severe photosensitivity or burns;
• excipient incompatibility and device-performance disputes;
• manufacturing failures involving sterility or particulate contamination;
• trade-secret disputes over sterile processing and impurity control.

A generic applicant must evaluate Orange Book certifications and potential patent litigation before launch. A settlement could include a delayed-entry date, supply arrangement, authorized-generic structure, or license to a formulation patent. The economic value of settlement depends on the size of the treated population, the availability of alternative photochemotherapy products, and the ability of the incumbent to maintain control of the photopheresis procedure.

What geographic markets offer the best opportunity?

The United States offers the clearest regulatory framework through FDA approval, Orange Book listings, ANDA litigation, and 505(b)(2) development. Europe and other markets may offer opportunities through national marketing authorizations, hospital procurement, and specialty distribution, but the regulatory and patent analysis must be performed country by country.

Geographic differentiation can arise from:

• local availability of sterile fill-finish;
• hospital reimbursement;
• photopheresis-center concentration;
• import requirements for controlled or light-sensitive products;
• local patent term and SPC status;
• reference-product availability;
• national substitution rules.

A company pursuing international commercialization should avoid assuming that U.S. FDA approval, Orange Book listings, or U.S. patent outcomes determine foreign market access.

Key Takeaways

• Methoxsalen is an old small molecule with limited molecule-level exclusivity opportunity.
• The strongest commercial targets are sterile solution stability, photoprotection, device compatibility, and oral dose uniformity.
• UVADEX-type development is more technically difficult than oral-capsule development because the product is used with an extracorporeal photopheresis system.
• Excipient patents are strongest when tied to measured improvements in stability, recovery, dissolution, or device performance.
• A 505(b)(2) strategy may support a differentiated reformulation but will not recreate new-chemical-entity exclusivity.
• Biosimilar competition is irrelevant; generic and hybrid competition are the material threats.
• The most valuable licensing packages would combine excipient technology, analytical methods, sterile manufacturing, and regulatory support.
• Commercial success depends on specialty distribution and photopheresis-center access as much as on formulation performance.

FAQs

Can methoxsalen be reformulated as a topical product?

A topical product could be developed, but it would require a new regulatory strategy addressing dermal absorption, local phototoxicity, dose control, stability, and UVA-treatment instructions. A topical formulation would not automatically be substitutable for an oral or extracorporeal product.

Is cyclodextrin suitable for methoxsalen?

Cyclodextrin may improve apparent aqueous solubility, but suitability depends on complex stability, concentration, route of administration, hemocompatibility, toxicity, container interaction, and the effect on methoxsalen exposure. A sterile cyclodextrin formulation would require extensive CMC and compatibility data.

Does methoxsalen have biosimilar competition?

No. Methoxsalen is a chemically synthesized small molecule. Competition would proceed through generic, hybrid, reformulated, or device-linked products rather than the FDA biosimilar pathway.

Can a new excipient create three years of FDA exclusivity?

A new excipient alone does not guarantee exclusivity. Three-year exclusivity generally requires approval supported by new clinical investigations essential to the approved change. The exclusivity would be product- and indication-specific.

What is the largest manufacturing barrier for UVADEX alternatives?

The largest barriers are sterile low-concentration solution manufacture, photostability control, container-closure qualification, and validated compatibility with the photopheresis circuit. These requirements can be more difficult to reproduce than the basic methoxsalen chemistry.

References

1. U.S. Food and Drug Administration. (n.d.). UVADEX (methoxsalen) sterile solution 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). Application of human factors engineering principles for combination products: Questions and answers.
4. International Council for Harmonisation. (2009). ICH Q8(R2): Pharmaceutical development.
5. International Council for Harmonisation. (2023). ICH Q9(R1): Quality risk management.
6. United States Pharmacopeia. (2024). General chapter <790>: Visible particulates in injections.
7. U.S. Food and Drug Administration. (1997). Q1B photostability testing of new drug substances and products.