List of Excipients in Branded Drug LEVOLEUCOVORIN

Generic Drugs Containing LEVOLEUCOVORIN

Company	Ingredient	NDC	Excipient
Hikma Pharmaceuticals USA Inc	levoleucovorin	0143-9558	HYDROCHLORIC ACID
Hikma Pharmaceuticals USA Inc	levoleucovorin	0143-9558	MANNITOL
Hikma Pharmaceuticals USA Inc	levoleucovorin	0143-9558	SODIUM HYDROXIDE
Sandoz Inc	levoleucovorin	0781-3201	SODIUM CHLORIDE

What are the Most Frequently-Used Excipients in LEVOLEUCOVORIN?

# Of NDCs	Excipient
3	HYDROCHLORIC ACID
3	MANNITOL
7	SODIUM CHLORIDE
10	SODIUM HYDROXIDE

Levoleucovorin Excipient Strategy, Formulation Patents, and Commercial Opportunities

Last updated: September 16, 2026

Levoleucovorin is a small-molecule folate rescue and fluoropyrimidine-modulating agent sold primarily as calcium levoleucovorin injection. The strongest commercial opportunities are formulation and supply-chain improvements rather than new pharmacology. Ready-to-use oncology bags, lower-volume presentations, extended in-use stability, pediatric dose flexibility, and improved container compatibility can create differentiation in a market where conventional generic injection is exposed to price competition.

Levoleucovorin has no biosimilar pathway. Generic competition proceeds through the abbreviated new drug application, or ANDA, route when a product can match the reference listed drug in dosage form, strength, route, active ingredient, and quality attributes. The principal formulation risks are precipitation, pH control, calcium-related compatibility, oxidation or degradation during storage, and the operational burden of pharmacy compounding.

What is levoleucovorin and how is it used?

Levoleucovorin is the pharmacologically active levo-isomer of folinic acid. In the United States, injectable products are used for methotrexate rescue and overdose management and in combination with fluorouracil for colorectal cancer. The reference product Fusilev was approved by the FDA in 2008. Khapzory, another branded levoleucovorin calcium injection, was approved in 2018. Generic levoleucovorin calcium injections are also marketed through the ANDA pathway.[1-3]

Attribute	Commercial significance
Active ingredient	Levoleucovorin, generally supplied as levoleucovorin calcium
Product class	Small-molecule folate analog
Main dosage form	Sterile injectable solution
Principal uses	Methotrexate rescue, methotrexate overdose, fluorouracil combination therapy
Primary customers	Hospitals, oncology clinics, specialty pharmacies, group purchasing organizations
Regulatory pathway	ANDA for conventional generics; 505(b)(2) may apply to materially differentiated products
Biosimilar exposure	None
Main differentiation levers	Concentration, container, ready-to-use presentation, stability, pediatric dosing, pharmacy workflow

The product is administered in clinical settings where preparation time, dose accuracy, sterility assurance, and inventory reliability have direct economic value. The formulation must also accommodate sequential or combination use with fluorouracil and other oncology medicines.

What excipients are used in levoleucovorin injection?

The excipient system is generally simple. Product labels identify water for injection and may include sodium chloride and pH-adjusting agents such as sodium hydroxide or hydrochloric acid, depending on the specific product and presentation.[1-3]

Excipient category	Formulation function	Key development issue
Water for injection	Vehicle	Sterility, endotoxin, container compatibility
Sodium chloride	Tonicity adjustment	Osmolality and infusion tolerability
Sodium hydroxide	pH adjustment	Stability window and local tolerability
Hydrochloric acid	pH adjustment	Final pH control and analytical reproducibility
Nitrogen or other process gas, where used	Headspace control	Oxidative stability and package validation
No preservative	Supports single-dose oncology use	Requires strong aseptic and container-closure controls

A low-excipient design is commercially advantageous. Oncology injectables are often administered to medically fragile patients, and institutional buyers generally prefer products without unnecessary preservatives, complex surfactant systems, or novel co-solvents.

The most important excipient variables are pH, ionic strength, buffer capacity, and the interaction between the formulation and the primary container. Adding a buffer may improve pH control but can increase ionic load, alter calcium behavior, complicate compatibility testing, or create a larger regulatory difference from the reference product.

How should an excipient strategy be designed for levoleucovorin?

A practical strategy should begin with the lowest-complexity formulation that provides acceptable shelf life and administration performance.

Preserve a simple aqueous formulation

A conventional aqueous formulation with water for injection, tonicity adjustment, and controlled pH has the clearest ANDA path. It also minimizes toxicological qualification and reduces the risk that an excipient becomes the commercial constraint.

The target should be a stable pH range rather than a single nominal value. Development should map degradation across pH, temperature, oxygen exposure, light exposure, and container contact. The final commercial specification must distinguish formulation-driven degradation from assay variability and stereochemical impurities.

Avoid unnecessary preservatives

Single-dose vials and pharmacy-administered oncology products do not require a preservative-driven multidose strategy. Preservatives can create compatibility, tolerability, and regulatory complications. A preservative-free formulation is more consistent with hospital use and may support premium positioning if paired with ready-to-administer packaging.

Evaluate tonicity against concentration

Sodium chloride is a straightforward approach to tonicity control, but the required amount can change as drug concentration changes. A higher-concentration product may reduce total infusion volume while producing a different osmolality profile. Development should compare:

• Undiluted vial administration.
• Dilution in 0.9% sodium chloride.
• Dilution in 5% dextrose where clinically appropriate.
• Small-volume syringe or minibag administration.
• Pediatric dosing at low absolute volumes.

The commercial objective is not simply maximum concentration. The product must remain compatible with common oncology workflows and demonstrate acceptable stability after dilution.

Control calcium-related compatibility

Levoleucovorin is supplied as a calcium salt. Calcium-containing formulations require compatibility testing with diluents, administration sets, filters, and co-administered drugs. The Fusilev labeling states that levoleucovorin should not be mixed in the same infusion with fluorouracil because a precipitate may form.[1]

This creates a formulation and packaging opportunity. A product cannot remove the underlying incompatibility through excipient selection alone, but it can reduce administration errors through clear labeling, separate-port packaging, sequential-dose kits, and ready-to-use presentations that enforce the correct workflow.

Screen container systems early

Levoleucovorin development should compare glass vials, polymer vials, prefilled syringes, and infusion bags. The assessment should cover:

• Adsorption or absorption of drug into polymers.
• Extractables and leachables.
• Oxygen permeability.
• Light transmission.
• Closure integrity.
• Particulate generation.
• Compatibility with elastomers, tubing, and filters.
• Stability after puncture and dilution.

A polymer container can provide a commercial advantage through lower breakage risk and easier pharmacy handling. It can also create a larger analytical and regulatory package than a conventional glass vial.

What formulations are protected by levoleucovorin patents?

Formulation protection would most plausibly cover a defined concentration, pH range, excipient ratio, container system, storage condition, dilution stability period, or method of administration. A simple claim to levoleucovorin calcium in water is likely to face substantial prior-art and obviousness pressure because injectable folinic-acid products have been commercially established for years.

The most defensible formulation patent positions would combine multiple technical elements, such as:

1. A specified levoleucovorin concentration.
2. A narrow pH range linked to improved stability.
3. A defined tonicity or ionic-strength range.
4. A particular vial, syringe, or infusion-bag material.
5. Demonstrated stability after dilution.
6. Reduced particulate formation.
7. A validated low-volume administration method.
8. A packaging configuration that prevents fluorouracil co-mixing.

A patent strategy based only on sodium chloride concentration or routine pH adjustment is vulnerable unless the applicant can show an unexpected stability, compatibility, or administration benefit.

Patent applicants should separate composition claims from package and method claims. A package claim can remain commercially useful even if a generic manufacturer avoids the claimed excipient composition. A method-of-use claim may cover administration sequencing or a particular oncology regimen, but enforcement can be more difficult where the prescribing and hospital-administration steps are divided among multiple actors.

When does levoleucovorin lose exclusivity?

Levoleucovorin’s principal market is already exposed to generic competition. The relevant commercial question is not a single compound-patent expiration date but whether any enforceable, listed product patent or regulatory exclusivity blocks a specific generic presentation.

Exclusivity element	Relevance to levoleucovorin
New chemical entity exclusivity	Generally not the central barrier for a folinic-acid isomer product
Orphan exclusivity	Not the primary market-exclusivity mechanism for the main injectable uses
Patent term	Depends on the particular reference product, patent, PTA/PTE, and listing status
ANDA competition	The principal route for conventional injectable generics
180-day generic exclusivity	May apply to a first eligible Paragraph IV filer
Biosimilar exclusivity	Not applicable
Formulation exclusivity	Could affect a differentiated concentration, container, or delivery format

Current Orange Book listings should be reviewed by reference product, strength, dosage form, and patent-use code before making a launch decision. The FDA Orange Book is the controlling source for listed patents and exclusivity associated with approved small-molecule products.[4]

Are there Paragraph IV challenges or levoleucovorin patent lawsuits?

A Paragraph IV filing is relevant only when an ANDA applicant certifies that a listed patent is invalid, unenforceable, or will not be infringed. A commercial assessment should review FDA Orange Book listings, ANDA litigation under the Hatch-Waxman framework, and the Federal Court’s Patent Center or PACER records.

The practical litigation risk for a new levoleucovorin injection is likely to be presentation-specific. A conventional generic may face limited patent exposure if no active listed patent blocks the reference product. A ready-to-use bag, novel concentration, or stability-enhanced product can create new patent positions, but those claims may also be challenged as obvious or anticipated.

No biosimilar litigation analysis is required because levoleucovorin is a small molecule. Settlement agreements, if any, should be assessed for:

• Agreed generic entry dates.
• Authorized-generic rights.
• Restrictions on a competing formulation.
• Supply or manufacturing provisions.
• Patent-prosecution cooperation.
• Treatment of future strengths and dosage forms.

A settlement affecting one vial strength may not resolve risk for another presentation.

What FDA pathway is best for a new levoleucovorin product?

ANDA pathway

An ANDA is the most efficient pathway for a product that matches the reference product’s dosage form, route, strength, active ingredient, and relevant quality attributes. The applicant must establish pharmaceutical equivalence and bioequivalence as applicable, along with injectable-product quality, sterility, particulate, stability, and container-closure data.[5]

An ANDA strategy favors:

• The same general aqueous dosage form.
• Conventional excipients.
• The same route of administration.
• A familiar vial configuration.
• No new clinical indication.
• No material change in administration method.

505(b)(2) pathway

A 505(b)(2) application may be more suitable for a product that introduces a new concentration, ready-to-use infusion bag, novel administration device, or other change not fully covered by an ANDA. The applicant may rely partly on FDA findings for an approved product while submitting additional data to support the modification.[6]

The 505(b)(2) route can support greater differentiation but carries higher development cost, more extensive CMC requirements, and potential patent-certification obligations. A reformulation should not use the 505(b)(2) pathway merely to avoid generic competition if the product can be approved through an ANDA.

What commercial opportunities exist for levoleucovorin excipients?

Ready-to-use infusion bags

A pharmacy-ready infusion bag can reduce compounding steps, preparation errors, and technician time. The commercial case is strongest in high-volume oncology centers and health systems with centralized sterile compounding.

The product should provide validated stability through the expected administration window, including transport, storage, overwrap requirements, and temperature excursions.

Prefilled syringes and small-volume presentations

A prefilled syringe or low-volume presentation could address pediatric dosing, outpatient infusion, and protocol-driven administration. The principal barriers are dose flexibility, device compatibility, microbial control, and the need to avoid excessive waste.

Higher-concentration injections

A concentrated formulation could reduce infusion volume and storage footprint. It must demonstrate acceptable osmolality, local tolerability, withdrawal accuracy, and dilution stability. Concentration claims are more defensible when linked to a measurable operational benefit.

Extended post-dilution stability

Hospitals value products that remain stable after dilution for a defined period. This can support batch preparation and reduce product waste. The claim must be supported by validated assay, degradant, particulate, sterility, and container-closure data.

Dual-product or sequential-administration systems

Because levoleucovorin and fluorouracil require controlled administration sequencing, a kit containing separate, clearly labeled components could reduce workflow errors. The commercial value would come from process control rather than a novel excipient.

Supply-chain differentiation

Injectable oncology products are exposed to shortages caused by manufacturing failures, sterile-filling constraints, raw-material interruptions, and container shortages. A manufacturer with redundant sterile capacity, dual-source excipients, and qualified alternative packaging can gain hospital contracts even without a premium formulation.

How does levoleucovorin compare with leucovorin?

Levoleucovorin and racemic leucovorin differ in stereochemical composition. Levoleucovorin contains the pharmacologically active levo-isomer, while conventional leucovorin contains a mixture of stereoisomers. The comparison affects dose, procurement economics, clinical protocol, and formulation equivalence.

Factor	Levoleucovorin	Racemic leucovorin
Stereochemistry	Levo-isomer	Mixture of stereoisomers
Formulation opportunity	Concentration, ready-to-use, stability	Broader generic and legacy product base
Regulatory comparison	Product-specific equivalence	Product-specific equivalence
Biosimilar risk	None	None
Commercial pressure	Generic injection competition	Established generic competition
Differentiation	Workflow and presentation	Cost, supply, and protocol fit

A levoleucovorin product should not assume that excipient similarity to leucovorin establishes therapeutic or regulatory equivalence. The active ingredient, salt form, strength, and reference product determine the applicable FDA pathway.

How strong is the levoleucovorin patent estate?

The strongest potential intellectual-property positions are likely to arise from formulation and packaging combinations rather than broad compound claims. Commercial patent strength should be assessed using four tests:

1. Whether the claims cover a product sold in meaningful quantities.
2. Whether a generic can design around the claimed excipient or container.
3. Whether the claims are listed in the Orange Book.
4. Whether the claims have supporting stability or compatibility data.

A narrow pH claim with no demonstrated technical effect is weaker than a claim supported by comparative degradation data. A container claim tied to reduced adsorption or particulate formation is more defensible than a generic claim to a vial. A method claim covering a widely used oncology protocol may have commercial value but can present enforcement challenges.

What generic launch risks exist for levoleucovorin?

A generic launch can proceed through several scenarios:

Launch scenario	Commercial result
First ANDA entrant with valid Paragraph IV position	Potential 180-day advantage, subject to litigation and eligibility
Multiple ANDA entrants after patent clearance	Rapid price erosion likely
Authorized generic launch	Lower prices and reduced first-filer economics
Differentiated 505(b)(2) product	Higher development cost but potential workflow premium
Ready-to-use product without direct equivalent	Hospital-contract opportunity
Shortage-driven launch	Rapid adoption if supply reliability is demonstrated

The largest risk for a conventional injectable is commoditization. The largest opportunity is to sell a measurable reduction in pharmacy labor, waste, preparation risk, or shortage exposure.

Key Takeaways

• Levoleucovorin is a small-molecule injectable with no biosimilar pathway.
• A simple preservative-free aqueous formulation is the lowest-risk development platform.
• The critical formulation variables are pH, tonicity, calcium-related compatibility, container interaction, and post-dilution stability.
• Ready-to-use infusion bags, prefilled syringes, low-volume presentations, and pediatric dose formats offer the clearest commercial differentiation.
• Formulation patent claims should combine excipient ranges with demonstrated stability, compatibility, or administration benefits.
• Orange Book status, Paragraph IV certifications, and litigation must be reviewed by reference product and presentation.
• Revenue data for levoleucovorin products are not consistently disclosed at the product level; commercial analysis should rely on hospital demand, generic count, contract pricing, and shortage history.
• The strongest business case is operational: lower compounding burden, reduced waste, better supply reliability, and fewer administration errors.

FAQs

Is levoleucovorin a biologic requiring biosimilar approval?

No. Levoleucovorin is a small-molecule drug. Competing products generally use the ANDA pathway rather than the biosimilar pathway.

Can a levoleucovorin formulation contain preservatives?

It can, but a preservative-free single-dose presentation is generally better aligned with oncology injection use. A preservative would require justification based on the intended container, dosing pattern, microbial-control strategy, and tolerability.

Can levoleucovorin be mixed with fluorouracil?

The Fusilev label warns against mixing levoleucovorin with fluorouracil in the same infusion because precipitation may occur. Administration sequencing and line compatibility must follow the approved labeling and validated institutional procedure.[1]

Is a ready-to-use levoleucovorin bag eligible for an ANDA?

Possibly, if the product remains pharmaceutically equivalent to the reference listed drug and satisfies FDA requirements. A materially different container, concentration, or administration method may require a 505(b)(2) assessment.

What is the most valuable excipient patent opportunity?

The strongest opportunity is usually a formulation-package combination supported by comparative data, such as improved stability after dilution, reduced adsorption in a polymer container, lower particulate formation, or a concentration that reduces infusion volume without compromising tolerability.

References

1. U.S. Food and Drug Administration. (2023). Fusilev (levoleucovorin calcium) injection prescribing information.
2. U.S. National Library of Medicine. (n.d.). DailyMed: Levoleucovorin calcium injection product labeling.
3. U.S. Food and Drug Administration. (2018). Khapzory approval package and prescribing information.
4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
5. U.S. Food and Drug Administration. (2023). ANDA submissions: Content and format of abbreviated new drug applications.
6. U.S. Food and Drug Administration. (2024). Applications covered by section 505(b)(2).