List of Excipients in Branded Drug COSYNTROPIN

Generic Drugs Containing COSYNTROPIN

Company	Ingredient	NDC	Excipient
Sandoz Inc	cosyntropin	0781-3440	MANNITOL
HF Acquisition Co LLC DBA HealthFirst	cosyntropin	51662-1567	MANNITOL
Mylan Institutional LLC	cosyntropin	67457-227	ACETIC ACID

What are the Most Frequently-Used Excipients in COSYNTROPIN?

# Of NDCs	Excipient
1	ACETIC ACID
4	MANNITOL
1	SODIUM HYDROXIDE

Cosyntropin Excipient Strategy and Commercial Opportunities

Last updated: September 24, 2026

Cosyntropin is a synthetic adrenocorticotropic hormone peptide used primarily for adrenal-function testing. Its commercial opportunity is concentrated in formulation improvement, supply reliability, ready-to-use presentation, hospital workflow, and international distribution rather than in new-molecule exclusivity. The reference formulation is a sterile lyophilized product containing cosyntropin and mannitol, typically reconstituted before administration. The core patent estate is unlikely to provide meaningful long-term protection because cosyntropin has been marketed for decades and its active sequence is established.

What is cosyntropin and how is it used?

Cosyntropin is the synthetic 24-amino-acid N-terminal fragment of human adrenocorticotropic hormone, also known as tetracosactide or ACTH 1-24. It stimulates the adrenal cortex and is used in the cosyntropin stimulation test to assess adrenal reserve.

The principal commercial indications include:

• Diagnosis of primary and secondary adrenal insufficiency.
• Evaluation of hypothalamic-pituitary-adrenal axis function.
• Select hospital and endocrinology applications where rapid cortisol-response testing is required.

Cosyntropin is administered intravenously or intramuscularly. A common diagnostic protocol measures serum cortisol before administration and at specified post-dose intervals, often 30 and 60 minutes. Product labeling and institutional protocols control the applicable dose and sampling schedule [1].

The product is generally supplied as a sterile powder for reconstitution. This format reduces the stability burden associated with an aqueous peptide solution but creates preparation steps, potential dosing delays, and opportunities for compounding or administration error.

What excipients are used in cosyntropin products?

The established cosyntropin formulation uses mannitol as the principal non-active ingredient. The product is supplied as a lyophilized cake and is reconstituted with sterile sodium chloride solution before use [1].

Formulation attribute	Established approach	Commercial implication
Active ingredient	Synthetic cosyntropin, ACTH 1-24	Peptide purity and sequence confirmation are central CMC requirements
Primary excipient	Mannitol	Supports cake structure and contributes to lyophilized-product development
Dosage form	Sterile lyophilized powder	Provides better dry-state stability than a liquid peptide formulation
Diluent	Sterile sodium chloride solution	Adds a preparation step before administration
Preservative strategy	Typically preservative-free single-dose presentation	Reduces preservative exposure but limits multidose use
Administration	Intravenous or intramuscular	Requires hospital or clinical-site handling
Container	Sterile glass vial is the established configuration	Container closure, adsorption, and reconstitution performance must be validated

Mannitol is commercially familiar and generally compatible with lyophilized parenteral products. Its use does not, by itself, provide meaningful differentiation. A follow-on developer would need to demonstrate that any change in bulking agent, buffer, surfactant, tonicity modifier, or reconstitution medium preserves peptide integrity and clinical performance.

What excipient strategy is most suitable for cosyntropin?

The strongest near-term strategy is to preserve the proven lyophilized format while improving reconstitution, stability, and handling. A liquid product may offer greater commercial differentiation but has materially higher development risk.

Lyophilized formulation with mannitol

A mannitol-based lyophilized formulation is the lowest-risk platform because it is aligned with the established product format. Development work should focus on:

• Residual moisture control.
• Reconstitution time.
• Cake appearance and mechanical integrity.
• Peptide recovery after reconstitution.
• Aggregation and fragmentation.
• Oxidation and deamidation.
• Adsorption to vial and syringe surfaces.
• In-use stability over the labeled administration period.

A formulation may use a low-concentration buffer, depending on cosyntropin’s pH-stability profile and the target product specification. Any buffer system should be selected through forced-degradation studies rather than by relying on general peptide-formulation practice.

Alternative bulking agents

Sucrose and trehalose may provide greater molecular stabilization than mannitol, but they may produce a different lyophilized cake and may require a separate optimization of freezing, primary drying, and secondary drying. Glycine may be considered as a bulking or stabilizing component, but the resulting product must meet reconstitution and particulate standards.

The commercial value of replacing mannitol is limited unless the alternative provides a measurable benefit, such as:

• Faster reconstitution.
• Longer refrigerated or controlled-room-temperature stability.
• Lower aggregation.
• Better recovery after dilution.
• Improved compatibility with a ready-to-use presentation.
• Lower manufacturing cost.

An excipient change that does not improve a clinically relevant or operational attribute may increase regulatory and CMC complexity without creating defensible market value.

Surfactants and peptide adsorption

Low-level polysorbate or poloxamer systems could reduce adsorption and interfacial stress in a liquid or reconstituted product. These excipients also introduce risks, including peroxide-mediated oxidation, particulate generation, extractables interaction, and lot-to-lot variability.

A surfactant strategy is more relevant to a liquid cosyntropin product, prefilled syringe, or cartridge than to a conventional single-dose lyophilized vial. Any use should be supported by peptide-specific compatibility studies and control of surfactant degradation products.

Liquid cosyntropin formulation

A ready-to-use liquid could eliminate reconstitution and reduce medication-preparation time. Its principal technical challenge is long-term stability. Aqueous peptide products are more exposed to hydrolysis, oxidation, aggregation, adsorption, and microbial-control requirements.

Potential stabilizing approaches include:

• Controlled pH.
• Tonicity adjustment.
• Low-level sugar or polyol.
• Surfactant protection.
• Low-oxygen headspace.
• Nitrogen overlay.
• Light-protective packaging.
• Low-temperature storage.

A liquid product may require refrigerated distribution unless stability data support a broader storage range. That requirement could reduce the operational advantage of eliminating reconstitution.

What formulations are protected by cosyntropin patents?

The principal commercial formulation is old and generally consists of cosyntropin in a sterile lyophilized dosage form with a conventional excipient system. No meaningful market strategy should assume that the core cosyntropin sequence, mannitol-based lyophilized composition, or basic diagnostic use remains protected by enforceable U.S. patent rights.

Patent protection could still arise from narrower claims covering:

• A specific stabilized aqueous formulation.
• A defined impurity profile.
• A particular lyophilization cycle linked to product quality.
• A prefilled delivery device.
• A ready-to-use cosyntropin composition.
• A novel method for reducing preparation error.
• A combination of cosyntropin with a specific diagnostic workflow.
• Manufacturing controls that produce a defined peptide-quality profile.

Such claims must satisfy novelty, non-obviousness, written description, enablement, and patent-term requirements. Broad claims directed only to cosyntropin and conventional excipients would face substantial validity risk because of the long history of ACTH-derived products and peptide formulation practice.

When does cosyntropin lose exclusivity?

Cosyntropin’s original small-molecule-style exclusivity period expired long ago. The product is not a new entrant with meaningful new chemical entity exclusivity. FDA exclusivity, if any, would depend on a later product-specific approval or qualifying clinical contribution rather than on the age of the active ingredient.

The principal commercial protections are therefore:

Protection category	Cosyntropin position
New chemical entity exclusivity	Expired or not relevant to current products
Orphan-drug exclusivity	Not generally the central protection for diagnostic adrenal testing
Pediatric exclusivity	Product-specific and not a foundational protection
Formulation patents	Possible for new liquid, stabilized, or device-based products
Method-of-use patents	Possible but likely narrow and vulnerable if based on established stimulation testing
Manufacturing patents	Possible where a process produces a differentiated impurity or stability profile
Regulatory exclusivity	Dependent on the specific approval pathway
Trade secrets	Relevant to peptide synthesis, purification, lyophilization, and analytical controls

What is the Orange Book status of cosyntropin?

Cosyntropin is a prescription drug, and applicable FDA-approved products may appear in the Orange Book depending on the sponsor, dosage form, and current marketing status. Orange Book analysis should distinguish:

• The reference listed drug.
• Approved abbreviated new drug applications.
• Current versus discontinued products.
• Listed patents and pediatric exclusivity.
• Product-specific dosage-form and route information.

A generic developer should not assume that an absence of listed patents eliminates all commercial risk. Unlisted patents can still be asserted, although they do not normally create the same statutory filing consequences as Orange Book-listed patents. For cosyntropin, the more material barriers are likely to be formulation equivalence, sterile manufacturing, API sourcing, product availability, and hospital purchasing contracts rather than a dense active patent estate [2].

How would a generic cosyntropin product reach the market?

A conventional lyophilized cosyntropin product could be positioned through an abbreviated new drug application if the reference product, dosage form, route, strength, and inactive-ingredient profile support that pathway. The developer would need to address:

• Pharmaceutical equivalence.
• Peptide identity and purity.
• Sterility and endotoxin limits.
• Assay and related substances.
• Reconstitution performance.
• Container-closure integrity.
• Stability.
• Inactive-ingredient justification.
• Comparative labeling.

A materially different liquid, device-based, or extended-stability product could require a 505(b)(2) strategy rather than a straightforward ANDA. That path may provide greater formulation flexibility and could support product-specific exclusivity, but it also requires a stronger clinical and bridging strategy.

Cosyntropin is not a conventional monoclonal antibody or recombinant protein product. Biosimilar substitution is therefore not the primary competitive framework. The relevant competitors are generic or follow-on synthetic peptide products approved under drug pathways.

What commercial opportunities exist for cosyntropin excipients?

Ready-to-use hospital presentation

The most visible opportunity is a ready-to-use liquid vial or prefilled syringe. The value proposition is operational:

• No reconstitution.
• Lower preparation burden.
• Reduced risk of dilution error.
• Faster diagnostic testing.
• Easier standardization across outpatient and inpatient sites.

The product would need to preserve the current dose and administration flexibility while meeting stability and packaging requirements.

Faster-reconstituting lyophilized vial

A lower-risk opportunity is a lyophilized product that reconstitutes rapidly with minimal foaming and low residual volume. This approach retains the stability advantages of a dry product and improves workflow without requiring a fully liquid formulation.

Dual-chamber syringe or vial system

A dual-chamber presentation could combine the dry peptide and diluent in one system. This may reduce handling steps while avoiding the full stability burden of an aqueous bulk formulation. The main obstacles are device cost, combination-product regulatory requirements, extractables and leachables, and manufacturing complexity.

Extended temperature stability

A product that tolerates short excursions outside refrigerated storage could improve use in emergency departments, outpatient endocrinology clinics, and decentralized testing sites. This opportunity depends on real-time and accelerated stability data, not simply on excipient substitution.

International formulation and licensing

Tetracosactide products have historically had stronger recognition in some non-U.S. markets than in the United States. A manufacturer with peptide manufacturing capacity, sterile fill-finish capability, or established hospital distribution could pursue regional licensing based on:

• Reliable API supply.
• Local registration.
• Clinical-lab distribution.
• Hospital tenders.
• Private-label supply.
• Differentiated ready-to-use packaging.

Licensing value would depend on regulatory status, manufacturing economics, and geographic access. The active ingredient alone is unlikely to command a high royalty rate without formulation, device, or supply-chain differentiation.

How strong is the cosyntropin patent estate?

The core estate is likely weak from a freedom-to-operate perspective because the active ingredient and basic use are longstanding. A new entrant could create stronger protection around a narrow product architecture.

Asset type	Relative strength	Reason
Cosyntropin composition of matter	Low	Historical use and expired foundational protection
Conventional mannitol lyophilization	Low to moderate	Likely exposed to prior art
Novel liquid formulation	Moderate	Depends on stability results and claim specificity
Prefilled or dual-chamber device	Moderate to strong	Device and formulation claims may provide layered protection
Manufacturing process	Moderate	Stronger if tied to measurable product-quality advantages
Diagnostic workflow	Low to moderate	Established stimulation-test protocols limit breadth
Stability-indicating analytical method	Low as a standalone patent	More valuable as a trade secret or specification control
Supply and distribution agreements	Commercially important	Contractual protection rather than patent exclusivity

What generic entry risks exist?

Generic entry risk is high for the legacy lyophilized product because the active ingredient is old, the clinical use is established, and the formulation is relatively simple. The principal constraints are commercial rather than legal.

A generic entrant could launch under several scenarios:

1. A direct lyophilized equivalent competes on price and supply reliability.
2. A shortage-driven entrant captures hospital contracts during supply disruption.
3. A ready-to-use product takes share through workflow savings rather than price.
4. A regional supplier competes through tender pricing and local registration.
5. A device-based product establishes a narrower, higher-margin segment.

The incumbent’s defensible advantages are likely to include manufacturing reliability, established diagnostic-lab relationships, formulary presence, and regulatory history. These advantages can erode quickly if the product experiences shortages or if a competitor offers a simpler administration format.

What litigation and Paragraph IV challenges affect cosyntropin?

No broad, high-value litigation pattern comparable to major blockbuster drugs should be assumed for legacy cosyntropin. Paragraph IV risk would arise primarily against any later-listed formulation or device patents, not against the historical cosyntropin molecule itself.

A follow-on developer should evaluate:

• Orange Book patent listings for the selected reference product.
• FDA patent-certification obligations.
• Any 30-month stay triggered by a Paragraph IV notice.
• Patent-term adjustment and pediatric exclusivity.
• Continuation applications covering liquid or device formulations.
• Patent litigation involving formulation, container closure, or manufacturing claims.

Settlement agreements are not a central known feature of the legacy cosyntropin market. If a later formulation receives patent protection, a settlement could include delayed entry, a license, supply rights, or geographic restrictions. Such terms would materially affect launch economics.

How does cosyntropin compare with competing adrenal testing products?

Attribute	Cosyntropin	Alternative adrenal-testing approaches
Primary role	Direct ACTH stimulation test	Basal cortisol, insulin tolerance test, metyrapone testing, or other clinical protocols
Product requirement	Sterile synthetic peptide	May not require a marketed peptide product
Operational burden	Reconstitution and timed blood draws	Varies by test
Commercial differentiation	Formulation, device, supply, workflow	Assay performance, lab integration, clinical convenience
Patent opportunity	Narrow formulation and device claims	May arise from assays, biomarkers, or diagnostic systems
Biosimilar relevance	Low	Generally low for non-biologic testing alternatives

Cosyntropin’s commercial position is supported by clinical familiarity and protocol standardization. Its weakness is that the diagnostic procedure requires coordinated dosing and timed sampling, which gives a workflow-oriented competitor an opportunity to differentiate.

Key Takeaways

• Cosyntropin is a mature synthetic peptide with limited value in foundational composition-of-matter exclusivity.
• The established formulation is a sterile lyophilized product using mannitol and requiring reconstitution.
• The strongest excipient strategy is to improve reconstitution, stability, peptide recovery, and handling while retaining the dry product.
• A liquid or prefilled presentation offers greater commercial differentiation but carries higher stability, packaging, and regulatory risk.
• Generic entry risk is high for conventional lyophilized cosyntropin.
• Biosimilar competition is not the principal framework; generic and 505(b)(2) pathways are more relevant.
• The best patent opportunities are narrow claims covering stabilized liquids, lyophilization processes, dual-chamber systems, prefilled devices, and defined product-quality attributes.
• Commercial value is likely to come from hospital workflow, supply reliability, international distribution, and reduced preparation burden.

FAQs

Can mannitol be replaced in a cosyntropin formulation?

Yes. Sucrose, trehalose, glycine, or other stabilizing systems may be evaluated, but replacement creates a need to establish peptide stability, cake performance, reconstitution, sterility, and regulatory comparability.

Is a liquid cosyntropin product commercially attractive?

Yes, if it provides meaningful reductions in preparation time and medication error. Its main risks are aqueous peptide instability, refrigeration requirements, adsorption, oxidation, and higher container-closure complexity.

Would a cosyntropin autoinjector have a large market?

Probably not as a broad consumer product because cosyntropin is primarily used in supervised diagnostic testing with timed blood sampling. A specialized clinic or hospital device could still create workflow value.

Can a cosyntropin formulation receive new patent protection?

Yes. Protection may be available for a genuinely novel and non-obvious liquid formulation, device configuration, manufacturing process, or stability profile. The claims would need to extend beyond routine excipient substitution.

What is the most practical commercial launch strategy?

A sterile lyophilized equivalent with reliable supply is the lowest-risk entry. A ready-to-use or dual-chamber presentation offers stronger differentiation but requires a more demanding CMC, device, and regulatory program.

References

1. U.S. Food and Drug Administration. (2023). Cortrosyn (cosyntropin) injection prescribing information. FDA/DailyMed.

2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

3. U.S. Food and Drug Administration. (2019). ANDAs for certain highly purified synthetic peptides. FDA guidance and regulatory materials.

4. U.S. Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary. USP.

5. European Medicines Agency. (2024). Tetracosactide product and regulatory information. EMA.