List of Excipients in Branded Drug SODIUM THIOSULFATE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Hope Pharmaceuticals	SODIUM THIOSULFATE	sodium thiosulfate	60267-705	BORIC ACID	2030-07-07
Hope Pharmaceuticals	SODIUM THIOSULFATE	sodium thiosulfate	60267-705	NITROGEN	2030-07-07
Hope Pharmaceuticals	SODIUM THIOSULFATE	sodium thiosulfate	60267-705	POTASSIUM CHLORIDE	2030-07-07
Hope Pharmaceuticals	SODIUM THIOSULFATE	sodium thiosulfate	60267-705	SODIUM HYDROXIDE	2030-07-07

Sodium Thiosulfate Excipient Strategy and Commercial Opportunities

Last updated: August 9, 2026

Sodium thiosulfate is an established active pharmaceutical ingredient with limited composition-of-matter protection and broad generic availability. Commercial value is concentrated in formulation execution: ready-to-use intravenous products, pediatric dosing, container compatibility, stability, differentiated administration, and indication-specific regulatory protection. The strongest opportunity is a low-particulate, low-manipulation product for cisplatin-induced ototoxicity and other hospital uses where preparation errors and infusion logistics affect adoption.

What pharmaceutical products contain sodium thiosulfate?

Sodium thiosulfate is marketed primarily as an intravenous drug for cyanide poisoning and as an otoprotective treatment for pediatric patients receiving cisplatin.

Product or use	Sponsor or market position	Dosage form	Commercial relevance
Pedmark	Fennec Pharmaceuticals	Ready-to-use IV infusion	Pediatric cisplatin-associated ototoxicity
Sodium thiosulfate injection	Multiple generic manufacturers	IV solution or concentrate	Cyanide poisoning and institutional use
Nithiodote	FDA-approved combination product	Sodium nitrite plus sodium thiosulfate injection	Emergency treatment of acute cyanide poisoning
Compounded or hospital-prepared products	Hospitals and compounders	Variable	Lower-cost, higher-preparation-burden alternative

The active ingredient is commonly supplied as sodium thiosulfate pentahydrate. It is highly water-soluble and is administered in relatively large quantities compared with most injectable drugs. That profile makes excipient selection, container compatibility, osmolarity, and infusion volume central commercial issues.

What excipients are used in sodium thiosulfate injections?

Sodium thiosulfate injectable products generally use a minimal excipient system because the active ingredient is itself highly soluble and contributes substantial ionic strength.

Typical formulation components include:

• Water for injection
• Sodium thiosulfate, commonly as the pentahydrate
• pH-adjusting agents, where required
• Sodium chloride or other tonicity agents in selected presentations
• Nitrogen headspace or oxygen-control measures during manufacturing
• Container-closure components selected to minimize extractables, adsorption, and chemical degradation

The exact inactive ingredient profile varies by product and presentation. Pedmark is supplied as a ready-to-use infusion product, while other sodium thiosulfate injections may be supplied in vials requiring dilution or institutional preparation. Product labels and approved prescribing information should control the final excipient and concentration assessment. [1,2]

Why is the excipient list usually short?

Sodium thiosulfate has three formulation characteristics that reduce the need for conventional excipient systems:

1. It dissolves readily in water.
2. It is administered at a high dose, so additional buffer or tonicity materials can materially affect the final osmolality.
3. It has chemical reactivity as a reducing agent, limiting the use of oxidizing or chemically incompatible excipients.

A minimal formulation can improve regulatory simplicity, reduce component risk, and lower the number of variables requiring long-term stability qualification.

What formulation risks affect sodium thiosulfate stability?

The principal risks are oxidation, pH drift, precipitation or crystallization, container interaction, and microbiological contamination after opening or dilution.

Oxidation and chemical degradation

Sodium thiosulfate can oxidize to tetrathionate and other sulfur-containing species. Oxygen exposure, light, elevated temperature, trace metals, and reactive container components can accelerate degradation. Formulation development should evaluate:

• Dissolved oxygen
• Headspace oxygen
• Trace metal contamination
• Light exposure
• Container-closure permeability
• Hold times after dilution
• Freeze-thaw exposure
• Compatibility with infusion sets and secondary containers

The use of conventional antioxidants is not automatically beneficial. An antioxidant may create new impurity pathways, alter pH, or complicate extractables and leachables assessments. A controlled manufacturing environment and an appropriate container may be more effective than adding a reactive stabilizer.

pH control

Sodium thiosulfate solutions require a controlled pH range to maintain chemical stability and product tolerability. Excessively acidic conditions can accelerate decomposition, while excessive alkalinity can create compatibility and administration concerns.

Potential pH-adjusting agents include hydrochloric acid or sodium hydroxide. Phosphate and other buffer systems should be assessed carefully because they can increase ionic load and create compatibility issues in concentrated formulations.

Osmolality and infusion volume

A high sodium thiosulfate load can produce a hypertonic solution. This affects:

• Peripheral versus central-line administration
• Infusion duration
• Local tolerability
• Pediatric fluid burden
• Hospital pharmacy preparation
• Labeling and administration instructions

A formulation that reduces infusion volume without increasing precipitation or tolerability risk could have commercial value, particularly in pediatric oncology and emergency medicine.

Container and closure compatibility

Glass vials, polymer bottles, flexible bags, elastomeric closures, and administration tubing can produce different stability outcomes. Relevant studies should assess:

• Sulfur-containing degradation products
• Metal-ion migration
• Adsorption to polymer surfaces
• Closure permeability
• Particulate formation
• Visible and subvisible particles
• Extractables and leachables
• Delivery-device compatibility

A ready-to-use product may require a more sophisticated container-closure system than a conventional vial because the product remains in contact with the primary container for its full shelf life.

What excipient strategies create commercial differentiation?

Ready-to-use formulation

The clearest opportunity is a ready-to-use IV product that removes reconstitution and dilution steps. Advantages include:

• Lower pharmacy labor
• Fewer calculation errors
• Reduced contamination risk
• Faster administration
• More predictable dose delivery
• Lower waste in high-value hospital settings

Pedmark’s commercial positioning reflects this logic. Its pediatric oncology use requires coordination with cisplatin administration, and a standardized presentation can reduce operational friction. [1]

Low-volume concentrated formulation

A concentrated product could reduce fluid burden and simplify administration. The technical challenge is maintaining acceptable osmolality, stability, particulate control, and infusion-site tolerability.

This strategy is most relevant to:

• Pediatric patients
• Patients receiving multiple concurrent infusions
• Emergency departments
• Ambulance and military medicine
• Hospitals with limited infusion capacity

Flexible-bag presentation

A polymer infusion bag can eliminate transfer steps and may improve pharmacy workflow. The formulation must be tested against the selected polymer, port, tubing, and overwrap. Sulfur-containing compounds and high ionic strength can create a different compatibility profile from conventional small-molecule injectables.

Unit-dose and weight-based presentations

Pediatric dosing creates an opportunity for multiple fixed-dose presentations, such as small-volume bags or vials calibrated to common body-weight bands. The commercial benefit is lower overfill, simpler dose calculation, and less wastage.

A manufacturer could pursue:

• Weight-band dosing
• Single-use bags
• Standardized oncology protocol kits
• Carton configurations for multi-cycle therapy
• Barcode-enabled hospital inventory management

Preservative-free, low-component formulation

A preservative-free formulation is generally preferable for IV oncology and pediatric use. A low-component formula also reduces the number of potential sensitizers and simplifies compatibility analysis.

For multidose containers, preservatives could improve in-use control, but the clinical and regulatory tradeoffs are substantial. Single-dose packaging is more consistent with high-risk injectable use.

What patent opportunities exist for sodium thiosulfate formulations?

The sodium thiosulfate molecule is old and does not support a meaningful new-molecule exclusivity strategy. Patent value is more likely to arise from formulation, use, packaging, manufacturing, and combination claims.

Patent category	Potential claim subject	Commercial value
Formulation	Concentration, pH, osmolality, impurity limits	Moderate if linked to measurable performance
Ready-to-use product	Stable premixed IV composition	Moderate to high
Container closure	Bag, vial, tubing, overwrap, oxygen-control system	Moderate
Method of use	Cisplatin otoprotection, dosing schedule, timing	High when clinically differentiated
Combination therapy	Sodium thiosulfate with cisplatin protocols or other agents	Moderate
Manufacturing	Oxygen reduction, impurity control, sterilization process	Moderate
Pediatric dosing	Weight-based administration and protocol design	Limited to moderate
Kit claims	Product plus administration components or dosing instructions	Limited unless strongly integrated

A formulation patent should establish a clear technical relationship between the claimed excipient system and a measurable improvement, such as improved shelf life, reduced impurity formation, lower particulate levels, or greater compatibility with a specific container.

Broad claims covering “sodium thiosulfate in water” are likely to face validity and obviousness challenges because aqueous injectable sodium thiosulfate products are established. Narrow claims tied to specific concentration ranges, stability data, impurity profiles, and container systems are more defensible.

When does sodium thiosulfate lose exclusivity?

Sodium thiosulfate has no practical new chemical entity exclusivity because the active ingredient has long-standing medical use. Product-level exclusivity depends on the specific brand, indication, formulation, and regulatory pathway.

Pedmark received FDA approval in 2022 for reducing the risk of ototoxicity associated with cisplatin in pediatric patients with localized, nonmetastatic solid tumors. Its commercial protection may derive from a combination of FDA regulatory exclusivity, listed patents, method-of-use claims, and clinical differentiation rather than from the sodium thiosulfate molecule itself. [1,3]

Generic entry analysis should distinguish among:

• Sodium thiosulfate injection for cyanide poisoning
• A ready-to-use pediatric otoprotection product
• A concentrated or low-volume formulation
• A specific dosing schedule used with cisplatin
• A premixed or device-integrated product

These products may contain the same active ingredient but face different regulatory and patent barriers.

What is the FDA regulatory status of sodium thiosulfate products?

FDA-approved sodium thiosulfate products include products for cyanide poisoning and Pedmark for cisplatin-associated ototoxicity reduction. Nithiodote combines sodium nitrite and sodium thiosulfate for acute cyanide poisoning. [1,2]

The regulatory pathway depends on the proposed product:

• A conventional sodium thiosulfate injection may rely on an abbreviated application if it demonstrates pharmaceutical equivalence and bioequivalence or qualifies under the applicable injectable-drug framework.
• A new ready-to-use formulation may require additional chemistry, manufacturing, and controls data.
• A new indication may require clinical evidence, labeling support, and method-of-use protection.
• A pediatric oncology product may obtain commercial advantages from the clinical evidence and regulatory designation associated with the indication.

The Orange Book should be reviewed for current listed patents, use codes, reference-listed drug status, and exclusivity dates for Pedmark and other applicable products. The regulatory status of each listed product can change through supplements, patent-list updates, and exclusivity events. [3]

What generic entry risks exist for sodium thiosulfate?

Generic entry risk is high for conventional injectable sodium thiosulfate because the active ingredient is old, soluble, and relatively uncomplicated to formulate.

Risk is lower for a differentiated product when the brand has:

• A clinically supported indication
• A proprietary ready-to-use presentation
• A narrow pediatric administration protocol
• Stable, low-impurity performance
• A protected container system
• Significant hospital purchasing integration
• Method-of-use patents that withstand Paragraph IV challenges

A generic applicant could pursue a conventional vial or concentrate without duplicating every feature of a ready-to-use branded product. That creates a potential “same active ingredient, different presentation” pathway. The brand’s commercial defense therefore depends on whether prescribers and hospitals value workflow, dosing reliability, and protocol integration enough to support a price premium.

Which companies are positioned to commercialize sodium thiosulfate?

Fennec Pharmaceuticals has the strongest branded position in pediatric cisplatin otoprotection through Pedmark. Generic injectable manufacturers compete in established cyanide-poisoning and hospital markets. Nithiodote occupies a combination-product position rather than a direct equivalent to Pedmark. [1,2]

Potential commercial entrants include:

• Generic injectable manufacturers
• Contract development and manufacturing organizations
• Oncology-focused specialty pharmaceutical companies
• Emergency-medicine suppliers
• Hospital injectable platforms
• Companies with flexible-bag or premix manufacturing capacity

The most attractive partner is likely to have sterile filling, polymer-bag capability, pediatric commercialization, and established hospital distribution.

How does sodium thiosulfate compare with other hospital injectable opportunities?

Attribute	Sodium thiosulfate	Conventional oncology supportive-care drug	New sterile injectable
Active-ingredient novelty	Low	Variable	Variable
Formulation complexity	Low to moderate	Moderate	Moderate to high
Manufacturing burden	High because of sterile dosage form	High	High
Patent leverage	Formulation and use focused	Often broader	Variable
Hospital demand	Indication-specific	Often broader	Product-dependent
Generic risk	High for basic injection	Variable	Variable
Differentiation potential	Strong through presentation	Usually stronger through indication	Strong if device-integrated

Sodium thiosulfate is more attractive as a formulation and delivery opportunity than as a conventional composition-of-matter opportunity.

What commercial opportunities have the highest priority?

The strongest opportunities are:

1. A ready-to-use pediatric oncology infusion with low preparation burden.
2. A lower-volume product designed for weight-based pediatric dosing.
3. A stable flexible-bag presentation with validated tubing compatibility.
4. A cyanide-poisoning product optimized for emergency storage and rapid deployment.
5. A kit containing sodium thiosulfate, administration components, and protocol-specific labeling.
6. A global product with packaging suitable for temperature excursions and decentralized hospitals.
7. A manufacturing process that reduces oxidation-related impurities and extends shelf life.

Revenue exposure depends on the size of the target indication, treatment uptake, product price, and hospital conversion. Publicly available product labeling does not establish a reliable standalone revenue figure for sodium thiosulfate across all manufacturers.

Key Takeaways

• Sodium thiosulfate has limited active-ingredient patent value because the molecule is established and widely available.
• Excipient strategy should prioritize chemical stability, oxygen control, pH, osmolality, particulate control, and container compatibility.
• Ready-to-use and low-volume pediatric products offer the clearest commercial differentiation.
• Formulation patents are strongest when tied to objective stability or compatibility improvements.
• Conventional sodium thiosulfate injections face high generic-entry risk.
• Pedmark’s value is linked to its pediatric cisplatin indication, clinical evidence, presentation, and regulatory position.
• Flexible bags, unit-dose formats, emergency kits, and weight-based presentations are credible commercial extensions.
• The Orange Book and current FDA labeling should be used to confirm live patents, exclusivity, use codes, and product-specific regulatory status.

FAQs

Can sodium thiosulfate be formulated without a buffer?

Yes. A buffer may not be necessary if the formulation maintains an acceptable pH throughout shelf life and administration. Eliminating a buffer can reduce ionic load and compatibility risk, but the decision requires stability and impurity data.

Is sodium thiosulfate suitable for a prefilled syringe?

A prefilled syringe is technically possible but may be commercially less efficient for high-dose administration. Syringe dimensions, delivered volume, extractables, plunger compatibility, and injection time could make a bag or vial more practical.

What manufacturing barrier is most important for sodium thiosulfate?

Sterile manufacturing and control of oxidation-related impurities are the principal barriers. The active ingredient is soluble, but high-dose sterile filling, container compatibility, particulate control, and shelf-life validation remain demanding.

Can an excipient create patent protection for sodium thiosulfate?

Yes, but only if the claimed excipient system produces a non-obvious and measurable technical result. A generic buffer or tonicity agent alone is unlikely to provide strong protection.

Is sodium thiosulfate a biosimilar opportunity?

No. Sodium thiosulfate is a small-molecule drug, not a biologic. Competitive products generally follow generic, hybrid, or new-drug pathways rather than the FDA biosimilar pathway.

References

1. U.S. Food and Drug Administration. (2022). Pedmark (sodium thiosulfate) injection, prescribing information.
2. U.S. Food and Drug Administration. (2023). Nithiodote (sodium nitrite and sodium thiosulfate) injection, prescribing information.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
4. International Council for Harmonisation. (2003). ICH Q1A(R2): Stability testing of new drug substances and products.
5. United States Pharmacopeia. (2024). General chapter <1207>: Package integrity evaluation.