List of Excipients in Branded Drug PEMETREXED DISODIUM

Generic Drugs Containing PEMETREXED DISODIUM

Company	Ingredient	NDC	Excipient
Dr Reddys Laboratories Inc	pemetrexed disodium	43598-386	HYDROCHLORIC ACID
Dr Reddys Laboratories Inc	pemetrexed disodium	43598-386	MANNITOL
Dr Reddys Laboratories Inc	pemetrexed disodium	43598-386	SODIUM HYDROXIDE
Amneal Pharmaceuticals LLC	pemetrexed	70121-1232	HYDROCHLORIC ACID
Amneal Pharmaceuticals LLC	pemetrexed	70121-1232	MANNITOL
Amneal Pharmaceuticals LLC	pemetrexed	70121-1232	SODIUM HYDROXIDE
Amneal Pharmaceuticals LLC	pemetrexed	70121-1233	HYDROCHLORIC ACID

What are the Most Frequently-Used Excipients in PEMETREXED DISODIUM?

# Of NDCs	Excipient
3	HYDROCHLORIC ACID
3	MANNITOL
3	SODIUM HYDROXIDE

Last updated: August 2, 2026

Executive summary: Pemetrexed disodium is a mature, genericized sterile oncology injectable with limited active-ingredient exclusivity but substantial formulation and supply-chain opportunities. The current commercial baseline is a preservative-free lyophilized powder containing pemetrexed disodium and mannitol, reconstituted with 0.9% sodium chloride before intravenous infusion. The strongest opportunities are ready-to-use presentations, shorter preparation workflows, improved stability, lower waste, global manufacturing, and differentiated hospital economics. Any new product must address injectable-drug regulations, extractables and leachables, container closure, compatibility, and the requirements for an ANDA or 505(b)(2) application.

Pemetrexed Disodium Excipient Strategy and Commercial Opportunities

What is the current formulation of pemetrexed disodium?

Pemetrexed disodium is marketed primarily as a sterile, preservative-free lyophilized powder for intravenous administration. The reference product, Alimta, uses mannitol as the principal bulking agent, with hydrochloric acid and sodium hydroxide used for pH adjustment during manufacture. The product is supplied in single-dose vials containing 100 mg or 500 mg of pemetrexed disodium equivalent [1].

Formulation attribute	Reference-product position
Active ingredient	Pemetrexed disodium
Dosage form	Sterile lyophilized powder
Route	Intravenous infusion
Primary excipient	Mannitol
pH agents	Hydrochloric acid and sodium hydroxide
Preservatives	None
Vial sizes	100 mg and 500 mg
Initial diluent	Preservative-free 0.9% sodium chloride
Typical reconstituted concentration	25 mg/mL
Further dilution	0.9% sodium chloride before infusion
Administration time	Approximately 10 minutes
Handling	Cytotoxic-drug precautions required

The label instructs healthcare professionals to reconstitute the 100-mg vial with 4.2 mL of preservative-free 0.9% sodium chloride and the 500-mg vial with 20 mL. The resulting solution is further diluted before infusion [1].

The formulation is deliberately simple. Mannitol provides cake structure and bulk during lyophilization without introducing a preservative or complex buffer system. The absence of antimicrobial preservatives reduces compatibility and toxicity concerns in an oncology product administered intravenously.

What excipients are most suitable for pemetrexed disodium?

Mannitol remains the lowest-risk commercial excipient because it is established in the reference product and in multiple generic formulations. A developer seeking an ANDA should generally avoid unnecessary excipient changes. A developer pursuing a differentiated presentation can evaluate alternative stabilizers, bulking agents, buffers, and tonicity agents, but each change increases development and regulatory burden.

Mannitol

Mannitol has several advantages:

• Established regulatory precedent in pemetrexed injection.
• Good freeze-drying performance.
• Low chemical reactivity.
• Broad availability from pharmaceutical-grade suppliers.
• Familiarity to contract manufacturers and hospital pharmacies.
• Compatibility with preservative-free injectable products.

Its limitations are also relevant. Mannitol can crystallize in ways that affect cake structure, reconstitution behavior, and long-term stability. The lyophilization cycle must control collapse temperature, residual moisture, vial-to-vial uniformity, and reconstitution time.

Trehalose and sucrose

Trehalose and sucrose may provide amorphous stabilization and can be evaluated where the development objective is improved solid-state stability or a more robust lyophilized cake. They may also alter reconstitution time, residual moisture, and osmolality.

The commercial case for replacing mannitol is weak unless the alternative delivers a measurable advantage, such as:

• Longer shelf life.
• Faster reconstitution.
• Better resistance to temperature excursions.
• Lower particulate formation.
• Improved compatibility with a ready-to-use liquid formulation.
• Lower manufacturing cost.

Sucrose and trehalose introduce different moisture and glass-transition profiles. A formulation that performs well in accelerated stability studies may not retain equivalent performance after shipping, storage, or repeated handling in hospital pharmacies.

Polyols and amino acids

Other development candidates may include sorbitol, glycine, or related stabilizing excipients. These materials can influence cake morphology, aggregation, reconstitution, and osmolality. Their use requires a clear technical rationale because the reference formulation already has a relatively narrow excipient profile.

Glycine may improve cake structure in some lyophilized systems but can create crystallization-related behavior that complicates process control. Sorbitol can be useful as a stabilizer or tonicity contributor but may increase sensitivity to moisture and thermal processing.

Buffer systems

A buffer may improve pH control in a liquid or reconstituted product, but it can also create new risks. Candidate systems include phosphate, citrate, histidine, and acetate buffers. The principal evaluation points are:

• Pemetrexed chemical stability across the intended pH range.
• Precipitation after dilution with sodium chloride.
• Interaction with vial glass and elastomer components.
• Compatibility with infusion bags and tubing.
• Risk of phosphate or citrate precipitation.
• Impact on osmolality and patient tolerability.

A buffered formulation may be commercially attractive for a ready-to-use product, but it is less aligned with the reference product and may require a 505(b)(2) pathway rather than a straightforward ANDA.

Which formulation platforms offer the strongest commercial opportunities?

The largest commercial opportunity is not a new excipient by itself. It is a presentation that reduces pharmacy labor, preparation errors, product waste, or hazardous-drug exposure.

Ready-to-use liquid infusion

A ready-to-use pemetrexed solution could eliminate reconstitution and reduce preparation time. Its main technical barriers are chemical stability, oxidation, pH drift, container compatibility, and shelf life.

A liquid product could be supplied in:

• A single-dose vial.
• A pharmacy-ready infusion bag.
• A prefilled syringe for controlled transfer.
• A closed-system-compatible container.

A ready-to-use product must demonstrate stability in the final container, not only in laboratory glassware. The study program should cover container orientation, light exposure, agitation, freeze-thaw stress, shipping vibration, microbial control, particulate matter, and extractables and leachables.

Concentrated solution

A concentrated liquid could reduce vial count and storage volume. It may be useful for hospitals that prepare multiple doses in centralized oncology pharmacies. Concentration increases the risk of precipitation, viscosity changes, local pH effects, and dilution-related incompatibility.

The commercial benefit must be measured against the additional handling burden. If the concentration requires complex dilution instructions or has a narrow compatibility window, it may not improve the hospital workflow.

Dual-chamber or co-packaged system

A dual-chamber vial or bag could combine pemetrexed with the diluent while maintaining a dry-state formulation until use. This approach may preserve the stability benefits of lyophilization and reduce manipulation.

The barriers include device development, combination-product considerations, container-closure validation, manufacturing complexity, and higher unit cost. The value proposition is strongest in markets with centralized oncology preparation and high labor costs.

Alternative vial sizes

The reference product uses 100-mg and 500-mg vials. Additional sizes, such as 50 mg, 250 mg, or 1 g, could reduce wastage depending on dosing patterns and patient body-surface area.

The economic analysis should model:

• Average dose by indication.
• Number of vials per dose.
• Residual drug discarded.
• Stability after reconstitution.
• Hospital purchasing practices.
• Reimbursement and vial-based billing.
• Regional dose-band policies.

A smaller vial can increase manufacturing and packaging cost but reduce wastage. A larger vial may lower the cost per milligram but increase unused product.

What regulatory pathways apply to new pemetrexed disodium products?

ANDA pathway

An ANDA is the most direct route for a conventional generic injectable that matches the reference product in active ingredient, dosage form, strength, route, and key formulation characteristics. The applicant must demonstrate pharmaceutical equivalence and bioequivalence as applicable, along with quality, sterility, container-closure, and manufacturing controls [2].

For a pemetrexed disodium lyophilized vial using mannitol and a closely aligned excipient system, the ANDA pathway is generally the preferred commercial strategy.

505(b)(2) pathway

A 505(b)(2) application may be appropriate for a materially different product, such as:

• A ready-to-use liquid.
• A new concentration.
• A different container or delivery system.
• A new reconstitution method.
• A formulation with a materially different excipient system.
• A presentation with a different administration or storage profile.

The 505(b)(2) pathway can support differentiation but may expose the product to additional clinical, stability, device, and patent requirements. The commercial case should justify the higher development cost through measurable hospital or payer value.

FDA drug master files and excipient controls

Excipient suppliers can support manufacturers through Type IV drug master files, pharmaceutical-grade specifications, impurity controls, and supply continuity. For oncology injectables, the supplier’s ability to provide consistent low-bioburden material, elemental impurity data, endotoxin controls, and change-notification support is commercially important.

What patents protect pemetrexed disodium products?

Pemetrexed’s core composition-of-matter and method-of-use exclusivity has largely expired in the United States. The principal historic patent estate originated with Eli Lilly and covered pemetrexed and its use in cancer treatment. Later litigation focused on patents associated with the vitamin supplementation regimen used with pemetrexed.

Protection category	Commercial relevance
Core pemetrexed composition	Historic protection; no longer the main barrier to U.S. generic entry
Use in mesothelioma and lung cancer	Historic method-of-use protection
Vitamin supplementation regimen	Relevant to historic Paragraph IV litigation and settlement timing
Lyophilized formulation	Potentially relevant where separately claimed and listed
Ready-to-use liquid	Potential new formulation claims
Container or delivery system	Potential device or formulation protection
Manufacturing process	Potential non-Orange Book barrier

The FDA Orange Book remains the controlling source for listed patents and regulatory exclusivity for approved U.S. products [3]. Patent status must be reviewed by product, strength, dosage form, and application. An applicant should not assume that expiration of a core compound patent eliminates every possible formulation or method-of-use risk.

When did pemetrexed lose exclusivity and when can generics launch?

U.S. generic entry began after expiration or settlement of the relevant Alimta patent protections. Multiple generic manufacturers have entered the market, including large injectable-drug companies and specialty generic suppliers. The exact entry date and scope depend on the product, ANDA approval status, Paragraph IV certifications, and settlement terms.

Paragraph IV challenges

Pemetrexed was subject to historic Paragraph IV litigation involving challenges to Eli Lilly patents. The disputes included patents relating to pemetrexed use with folic acid and vitamin B12 supplementation. Settlement agreements affected the timing and conditions of generic entry.

For a new applicant, the current practical issue is less the historical litigation and more the residual risk from:

• Newly listed formulation patents.
• Patent claims directed to a specific liquid presentation.
• Manufacturing-process patents.
• Device claims covering a dual-chamber or ready-to-use system.
• Patent litigation against a differentiated 505(b)(2) product.

Settlement agreements

Settlement terms in the pemetrexed market historically controlled certain generic launch dates and authorized-entry arrangements. Commercial diligence should distinguish between:

1. An ordinary ANDA launch after patent expiration.
2. A settlement-permitted early launch.
3. An authorized generic arrangement.
4. A launch subject to supply, dosage-form, or territory restrictions.

A company entering with the same lyophilized product faces a different legal profile from a company introducing a new liquid formulation. The latter may create its own patent estate but may also attract separate infringement claims.

What is the Orange Book status of pemetrexed disodium?

The Orange Book identifies approved drug products, therapeutic equivalence information, patents submitted by sponsors, and regulatory exclusivity where applicable [3]. Pemetrexed disodium generic products are generally evaluated as injectable equivalents to the relevant reference product.

The key diligence questions are:

• Which reference listed drug is cited by each ANDA?
• Are any patents currently listed for the relevant strength and dosage form?
• Is the product eligible for a therapeutically equivalent rating?
• Does the product have an approved labeling carve-out for a patented method of use?
• Are any exclusivity periods still active for a particular applicant?

A generic product with a standard injectable presentation can compete primarily on price, supply reliability, shortage performance, and contracting. A differentiated formulation may receive less direct Orange Book substitutability and may need to create value through convenience or workflow savings.

How strong is the pemetrexed disodium patent estate?

The active-ingredient patent estate is weak as a barrier to conventional U.S. generic entry because the principal compound and clinical-use protections are mature. The formulation patent estate can be stronger for a new product, but only if the claims cover a technically meaningful feature that competitors cannot easily design around.

Stronger patent targets

Potentially defensible claims may cover:

• A specific liquid concentration with demonstrated stability.
• A defined pH range that prevents precipitation.
• A container-closure system that controls adsorption or leachables.
• A lyophilization cycle linked to a distinctive solid-state profile.
• A dual-chamber delivery system.
• A ready-to-use bag with validated in-use stability.
• A low-waste vial configuration.
• A manufacturing process that improves impurity control or yield.

Weaker patent targets

Claims are less commercially durable when they cover:

• Routine substitution of mannitol with another common bulking agent.
• Broad use of conventional buffers.
• Standard vial configurations.
• Ordinary reconstitution with sodium chloride.
• Formulation ranges that overlap heavily with known products.

Patent value depends on enforceability, freedom to operate, and whether the formulation produces a clinically or operationally relevant advantage.

What manufacturing and IP barriers affect pemetrexed opportunities?

Pemetrexed is a cytotoxic oncology product. Sterile manufacturing capacity, containment, operator protection, and quality systems are significant barriers to entry. A new manufacturer must control:

• Potent-compound exposure.
• Cross-contamination.
• Sterility assurance.
• Endotoxin levels.
• Particulate matter.
• Residual solvents and degradation products.
• Lyophilization uniformity.
• Vial fill accuracy.
• Container-closure integrity.
• Hazardous-drug shipping and handling.

The active pharmaceutical ingredient is commercially available from multiple suppliers, but supplier qualification remains critical. Dual sourcing may protect against shortages and improve negotiating leverage. A supplier with a validated route, reliable impurity profile, and regulatory support can be more valuable than the lowest-cost source.

Geographic expansion is attractive in markets where pemetrexed remains supplied mainly as an imported lyophilized product. Local fill-finish, regional packaging, or hospital-ready presentations can reduce logistics costs. The product must still satisfy country-specific requirements for sterile manufacturing, labeling, pharmacopoeial compliance, and pharmaceutical equivalence.

How does pemetrexed compare with competing oncology injectables?

Pemetrexed competes with other non-small-cell lung cancer therapies, including platinum combinations, docetaxel, gemcitabine, targeted therapies, and immune checkpoint inhibitors. Its commercial demand is linked to treatment guidelines, biomarker-defined populations, combination use, and local reimbursement.

Product characteristic	Pemetrexed disodium	Common generic cytotoxic injectables	Targeted or biologic oncology products
Product type	Small-molecule antifolate	Small-molecule cytotoxics	Small molecules or biologics
Biosimilar exposure	None	None	Often material for biologics
Formulation baseline	Lyophilized vial	Lyophilized or liquid	Liquid, lyophilized, or device-based
Main generic lever	Price, supply, workflow	Price and supply	Clinical differentiation and access
Excipient opportunity	Ready-to-use, stability, reduced waste	Similar	Often greater formulation complexity
Manufacturing barrier	Sterile cytotoxic production	Sterile production	Biologic or complex-device production

There is no biosimilar pathway for pemetrexed because it is a chemically synthesized small molecule. The relevant competitive pathway is generic substitution and, for materially different presentations, the 505(b)(2) route.

What commercial opportunities exist for excipient suppliers?

Excipient suppliers can participate in the pemetrexed market without owning the finished drug product. The most defensible opportunities involve complete technical packages rather than commodity supply alone.

Potential offerings include:

• High-purity mannitol qualified for sterile lyophilization.
• Trehalose or sucrose systems supported by freeze-drying data.
• Low-endotoxin excipients for cytotoxic injectables.
• Ready-to-use liquid stabilization platforms.
• Container-closure compatibility packages.
• Extractables and leachables data.
• Lyophilization cycle development.
• Stability-indicating analytical methods.
• Regulatory documentation and change-control support.
• Dual-source supply agreements.

A supplier that can demonstrate faster reconstitution, lower particulate risk, longer in-use stability, or improved shipping robustness has a stronger basis for premium pricing than one selling a standard excipient at a marginally lower cost.

What revenue exposure and launch scenarios matter?

Pemetrexed is a mature product, so revenue exposure is concentrated in volume, price, and contract position rather than exclusivity. The principal launch scenarios are:

Low-cost lyophilized generic

This is the lowest-risk entry strategy. It requires limited formulation differentiation and competes on manufacturing cost, supply reliability, and hospital contracts. Margin compression is likely once several suppliers qualify.

Premium low-waste presentation

A smaller vial or optimized strength may reduce discarded drug. The product can command a premium if the savings from lower waste exceed the acquisition-price increase.

Ready-to-use liquid

This has the largest potential workflow value but also the highest technical and regulatory risk. Commercial success depends on proving a meaningful reduction in pharmacy preparation time and hazardous-drug manipulation.

Regional contract manufacturing

A manufacturer can target countries or hospital systems with limited access to reliable pemetrexed supply. Local fill-finish and institutional contracts may produce better economics than competing globally on commodity price.

Authorized or co-branded supply

A high-quality generic manufacturer may pursue licensing, co-development, or supply arrangements with a branded oncology company, hospital distributor, or injectable specialist. The strongest deal structure would link territory rights or preferred supply to a differentiated presentation rather than an undifferentiated vial.

What should an excipient and formulation development plan prioritize?

A commercially disciplined program should follow this sequence:

1. Establish the reference-product composition, reconstitution profile, stability, and packaging.
2. Confirm whether the target is an ANDA-equivalent product or a differentiated 505(b)(2) product.
3. Screen mannitol-based formulations first because they have the lowest regulatory and technical risk.
4. Evaluate liquid and dual-chamber concepts only if they produce measurable workflow or waste reduction.
5. Test compatibility with sodium chloride infusion bags, tubing, filters, and closed-system transfer devices.
6. Build an extractables, leachables, particulate, and container-closure program early.
7. Model vial waste and pharmacy labor by dose distribution and market.
8. Conduct a product-specific Orange Book and freedom-to-operate review before finalizing the formulation.
9. Secure dual-source excipient and active-ingredient supply.
10. Protect any genuine formulation advantage with composition, process, container, and use claims.

Key Takeaways

• The reference pemetrexed disodium product is a preservative-free lyophilized powder based primarily on mannitol.
• A conventional mannitol-based generic has the lowest regulatory risk but faces intense price competition.
• Ready-to-use liquid, dual-chamber, and low-waste vial presentations offer the strongest commercial differentiation.
• There is no biosimilar opportunity because pemetrexed is a chemically synthesized small molecule.
• Core composition and historic use patents are mature; new formulation and delivery-system claims are more relevant to future exclusivity.
• Pemetrexed products require sterile cytotoxic manufacturing, strong containment, and reliable container-closure controls.
• Excipient suppliers can create value through formulation support, stability data, regulatory files, and supply security rather than commodity pricing alone.

FAQs

Can pemetrexed disodium be formulated without mannitol?

Yes. Alternative bulking agents or stabilizers can be evaluated, but the change may increase development risk and move the product away from the reference formulation. A replacement should deliver a documented advantage in stability, reconstitution, manufacturability, or storage.

Is a liquid pemetrexed product automatically eligible for an ANDA?

No. A materially different liquid formulation may require a 505(b)(2) application, depending on the reference product, formulation differences, bioequivalence approach, and FDA requirements.

What is the best excipient for a ready-to-use pemetrexed solution?

No single excipient is established as universally best. The selection must balance pH control, chemical stability, precipitation risk, osmolality, container compatibility, and shelf life. Mannitol is the established reference excipient for the lyophilized product, not necessarily for a liquid presentation.

Does pemetrexed have biosimilar competition?

No. Pemetrexed is a small-molecule drug and competes through generic-drug pathways, not the biosimilar pathway.

Can a new pemetrexed formulation obtain patent protection?

Yes, if it contains a novel and non-obvious composition, concentration, container system, manufacturing process, or use. Routine excipient substitution or standard injectable packaging is less likely to produce strong enforceable protection.

References

1. U.S. Food and Drug Administration. (2024). Alimta (pemetrexed for injection) prescribing information.
2. U.S. Food and Drug Administration. (2024). Abbreviated new drug application (ANDA) process.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. U.S. Food and Drug Administration. (2024). Drug products approved under section 505(b)(2) of the Federal Food, Drug, and Cosmetic Act.
5. DailyMed. (2024). Pemetrexed for injection prescribing information. National Library of Medicine.