Drugs Containing Excipient (Inactive Ingredient) MONOSODIUM CITRATE

Branded drugs containing MONOSODIUM CITRATE excipient, and estimated key patent expiration / generic entry dates

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Mission Pharmacal Company	BINOSTO	alendronate sodium	0178-0101	MONOSODIUM CITRATE
ASCEND Therapeutics	BINOSTO	alendronate sodium	17139-400	MONOSODIUM CITRATE
Rebel Distributors Corp	TAMIFLU	oseltamivir phosphate	42254-092	MONOSODIUM CITRATE
Mayer Laboratories Inc	TODAY VAGINAL CONTRACEPTIVE	nonoxynol-9	44376-100	MONOSODIUM CITRATE

Generic drugs containing MONOSODIUM CITRATE excipient

Company	Ingredient	NDC	Excipient
Teva Pharmaceuticals USA Inc	oseltamivir phosphate	0093-8180	MONOSODIUM CITRATE
Mission Pharmacal Company	alendronate sodium	0178-0101	MONOSODIUM CITRATE
Lannett Company Inc	oseltamivir phosphate	0527-5137	MONOSODIUM CITRATE
Torrent Pharmaceuticals Limited	erythromycin	13668-606	MONOSODIUM CITRATE

Monosodium Citrate Pharmaceutical Excipient Market Dynamics and Financial Trajectory

Last updated: August 23, 2026

Monosodium citrate is a low-volume, price-sensitive pharmaceutical excipient used primarily as a buffering agent, pH adjuster, chelating aid, and formulation stabilizer. The market is fragmented and largely private, with no reliable public revenue series dedicated specifically to monosodium citrate. Its financial trajectory is tied to citric acid, sodium chemicals, energy, water, packaging, analytical testing, and pharmaceutical-grade qualification costs rather than to proprietary intellectual property.

The strongest commercial positions belong to manufacturers that can supply consistent pharmacopeial quality, validated impurity profiles, reliable documentation, and regional regulatory support. The compound has limited standalone patent protection and low switching barriers in applications where other citrate salts or buffer systems are acceptable.

What is monosodium citrate and how is it used in pharmaceuticals?

Monosodium citrate is the monosodium salt of citric acid. It is also referred to as sodium dihydrogen citrate or sodium citrate monobasic. Its molecular formula is C6H7NaO7, and its molecular weight is approximately 214.11 g/mol for the anhydrous form.

Attribute	Monosodium citrate
Primary chemical identity	Sodium dihydrogen citrate
Molecular formula	C6H7NaO7
Approximate molecular weight	214.11 g/mol
Main pharmaceutical functions	Buffer, pH adjuster, chelating aid, stabilizer
Typical dosage-form relevance	Oral liquids, parenterals, reconstitution systems, solid formulations
Commercial classification	Functional excipient and processing ingredient
Patent position	Generally weak at the composition level
Principal cost drivers	Citric acid, sodium source, utilities, purification, testing, packaging

Monosodium citrate is useful where a formulation requires acidic buffering capacity without relying exclusively on citric acid. It may be combined with disodium or trisodium citrate to create a defined citrate buffer system.

The precise commercial identity matters. Buyers must distinguish monosodium citrate from trisodium citrate, sodium citrate dihydrate, citrate buffer blends, and generic "sodium citrate" specifications. These materials are not interchangeable on a weight-for-weight basis because their sodium content, molecular weight, hydration state, pH behavior, and buffering capacity differ.

What pharmaceutical formulations are protected by monosodium citrate?

Monosodium citrate itself generally does not provide meaningful formulation exclusivity. Protection, where it exists, is more likely to attach to a finished dosage form, delivery system, concentration range, combination, or manufacturing process.

Formulation and method-of-use protection

Potentially relevant claim categories include:

• A defined citrate buffer range in an injectable or oral formulation.
• A stability-enhancing excipient combination.
• A specific pH range that improves active pharmaceutical ingredient stability.
• A reconstitution system with a defined concentration of citrate salt.
• A liquid formulation with reduced precipitation, aggregation, oxidation, or degradation.
• A method of administering a drug using a citrate-containing composition.
• A pharmaceutical composition with a defined osmolality, sodium concentration, or preservative system.

These claims usually protect the drug product rather than monosodium citrate as a chemical substance. A supplier of the excipient normally does not control the resulting formulation patent unless it contributed proprietary technology or entered a licensing arrangement.

Patent strength

The composition-of-matter patent position is weak because monosodium citrate is an established chemical compound with long-standing food, pharmaceutical, and industrial use. New patent value would need to arise from a specific manufacturing improvement, particle form, purity profile, application, or formulation combination.

Patent category	Likely strength for monosodium citrate
Composition of matter	Very low
Conventional manufacture	Low, absent a novel process
High-purity production	Moderate only if the process is genuinely differentiated
Particle engineering	Potentially moderate
Drug-specific formulation	Moderate to strong, depending on claim scope
Method of use	Application-specific
Trade secrets	Often more relevant than patents for process control

Publicly visible patent activity should therefore be screened around the finished pharmaceutical product and its formulation, not only by searching for "monosodium citrate." A narrow excipient reference in a patent does not necessarily create an enforceable barrier to sourcing the material from another qualified manufacturer.

How large is the monosodium citrate pharmaceutical excipient market?

No authoritative public source reports a standalone global market size for pharmaceutical-grade monosodium citrate. Market research reports that group "sodium citrate," "citrate salts," or "pharmaceutical excipients" do not isolate monosodium citrate reliably enough to support a defensible revenue estimate.

The addressable market is likely small relative to major excipients such as microcrystalline cellulose, lactose, starch, povidone, polyethylene glycol, magnesium stearate, and polysorbates. Monosodium citrate is a functional ingredient with targeted use rather than a high-volume universal excipient.

The market has three overlapping segments:

1. Pharmaceutical-grade material sold under compendial or customer-specific specifications.
2. Food-grade monosodium citrate used in less demanding applications.
3. Technical or industrial citrate material used outside regulated drug manufacturing.

Pharmaceutical volume is limited by formulation-specific demand, but unit economics are higher because of qualification, testing, quality systems, audit support, and documentation.

What drives monosodium citrate excipient pricing?

Pricing is driven less by chemical scarcity than by compliance and supply reliability.

Raw materials and manufacturing

Citric acid is the main upstream input. Citric acid production depends on fermentation capacity, carbohydrate feedstocks, utilities, labor, logistics, and regional operating costs. Sodium hydroxide or another sodium source contributes a smaller portion of the direct cost, but caustic soda prices and supply conditions can affect conversion economics.

Manufacturing costs also include:

• Purified water and controlled process systems.
• Crystallization and drying.
• Milling and particle-size control.
• Heavy-metal, elemental impurity, microbial, and endotoxin testing where applicable.
• Packaging in pharmaceutical-grade bags or drums.
• Batch release and retain-sample management.
• Audit, regulatory, and change-control support.

For pharmaceutical buyers, the cost of failure is often higher than the purchase price. A low-cost supplier that triggers requalification, deviation investigations, or a regulatory filing may be commercially unattractive.

Pricing structure

Monosodium citrate is likely to follow a tiered pricing model:

Purchase profile	Commercial characteristics
Food or industrial grade	Lowest price, limited pharmaceutical documentation
Standard pharmaceutical grade	Higher price, compendial testing and quality documentation
Customer-qualified grade	Premium pricing, audits, change notification and supply commitments
Custom particle size or low-impurity grade	Highest pricing, smaller production runs and added testing

Price competition is strongest when the buyer can qualify multiple suppliers and when the formulation can use another citrate salt. Pricing power improves when a supplier is embedded in a validated drug product and changing sources would require regulatory notification or comparability work.

What is the financial trajectory for monosodium citrate suppliers?

The financial trajectory is likely to be steady rather than high-growth. Revenue expansion depends on pharmaceutical production volumes, new formulation approvals, geographic qualification, and conversion of food-grade or industrial customers into regulated accounts.

Base-case trajectory

The base case has low-single-digit nominal growth in mature markets, supported by:

• Continued use of oral and liquid formulations.
• Growth in generic and contract pharmaceutical manufacturing.
• Expansion of regulated production in Asia-Pacific and emerging markets.
• Demand for reliable buffer systems in biologic and injectable development.
• Higher documentation and quality requirements that favor established suppliers.

Upside case

An upside scenario would require one or more of the following:

• Adoption in a high-volume injectable or biologic product.
• Qualification as part of a large contract development and manufacturing organization network.
• Demand for low-endotoxin or low-elemental-impurity material.
• Supply disruption affecting incumbent suppliers.
• Expansion into prequalified formulation systems or ready-to-use buffer blends.

Downside case

Downside risks include:

• Substitution by trisodium citrate, disodium citrate, citric acid, phosphate, acetate, or other buffer systems.
• Reduced demand for a drug product using the excipient.
• Customer consolidation and centralized procurement.
• Excess citric acid and citrate-salt capacity.
• Falling freight and commodity costs that intensify price competition.
• Failure to maintain pharmacopeial compliance or change-control discipline.

Because major manufacturers generally do not disclose monosodium citrate sales separately, company-level revenue exposure cannot be calculated from public filings. Public financial statements usually report broad food ingredients, specialty ingredients, pharmaceutical excipients, or industrial chemicals rather than individual citrate salts.

Which companies compete in the monosodium citrate supply chain?

Competition is likely to include large citrate producers, specialty excipient manufacturers, regional chemical companies, and distributors that repackage or qualify material for pharmaceutical customers.

The relevant competitive groups are:

• Integrated citric acid and citrate producers.
• Specialty pharmaceutical excipient suppliers.
• Regional manufacturers with pharmacopeial production.
• Contract manufacturers and distributors.
• Formulation companies producing premixed citrate buffers.

A supplier’s competitive position should be assessed using the following criteria:

Evaluation factor	Commercial relevance
USP-NF, Ph. Eur., BP or equivalent conformity	Determines regulatory acceptability
GMP status	Required for pharmaceutical supply chains
DMF or regulatory support	Reduces customer filing burden
Dual-site manufacturing	Reduces interruption risk
Batch-to-batch consistency	Supports validated formulations
Elemental impurity control	Important for injectable and sensitive products
Microbial and endotoxin control	Critical for sterile or high-risk applications
Change-notification policy	Limits requalification risk
Regional inventory	Reduces lead times
Audit history	Affects supplier approval

Supplier concentration may be higher in pharmaceutical-grade material than in food-grade material because qualification is costly and buyers are reluctant to change an approved source.

What is the FDA regulatory status of monosodium citrate?

The FDA regulates excipients through the finished drug approval process, the applicable monographs, inactive-ingredient information, and manufacturing controls. A substance may have a history of use without receiving independent FDA approval as a drug.

FDA’s Inactive Ingredient Database is the primary public tool for reviewing excipient precedent by route and dosage form. The database does not establish universal approval for every concentration, route, or product type. The relevant question is whether the proposed use falls within established precedent and whether the finished product is adequately justified in its regulatory filing (U.S. Food and Drug Administration, n.d.-a).

Sodium citrate is also listed in FDA food regulations as a substance generally recognized as safe for specified uses. Food-use status does not automatically establish pharmaceutical suitability or sterile-product acceptability (U.S. Food and Drug Administration, n.d.-b).

Pharmaceutical buyers should verify:

• Exact chemical form and hydration state.
• Applicable USP-NF, Ph. Eur., BP, or JP monograph.
• Route-specific precedent in the FDA Inactive Ingredient Database.
• Residual solvent and elemental impurity controls.
• Microbial limits and endotoxin requirements.
• Container-closure compatibility.
• Nitrosamine and extractables/leachables risk where relevant.
• Supplier GMP and change-control systems.

What is the Orange Book status of monosodium citrate?

Monosodium citrate is not expected to have an independent Orange Book listing because the Orange Book lists approved drug products, their active ingredients, dosage forms, patent information, and exclusivity status rather than standalone excipients.

The relevant Orange Book analysis concerns drug products that contain monosodium citrate. A listed patent may cover the active ingredient, formulation, method of treatment, dosing regimen, or delivery technology. The excipient’s presence does not by itself create Orange Book exclusivity.

For a product-specific review, the analyst must examine:

• Approved drug product and dosage form.
• Listed patents under the product’s reference listing.
• Pediatric, orphan, new chemical entity, or other exclusivity.
• Paragraph IV certifications from abbreviated new drug applicants.
• Litigation under the Hatch-Waxman framework.
• Settlement terms affecting generic launch.

When does monosodium citrate lose exclusivity?

Monosodium citrate has no meaningful standalone regulatory exclusivity period. It is an established excipient, not a new chemical entity with independent drug exclusivity.

Exclusivity risk attaches to the finished product using the excipient. The relevant dates are therefore product-specific:

Exclusivity or barrier	Relevance to monosodium citrate
New chemical entity exclusivity	Applies to the active drug, not the excipient
Orphan-drug exclusivity	Applies to the designated drug indication
Pediatric exclusivity	Adds six months to qualifying protections
Patent term	Depends on the finished-product patent
Formulation patent	May delay generic substitution
Method-of-use patent	May affect labeled indication or carve-out strategy
Regulatory exclusivity	Depends on the approved product and pathway

A generic applicant can usually use the same excipient or a functionally equivalent excipient unless a valid product patent or regulatory restriction limits the formulation.

What generic entry risks exist for products containing monosodium citrate?

The excipient creates limited generic-entry risk. Generic competition is more likely to be affected by:

• Active-ingredient patent expiry.
• Drug-device integration.
• Complex liquid or injectable formulation requirements.
• Stability and impurity-control specifications.
• Demonstration of bioequivalence.
• Manufacturing process complexity.
• Limited availability of qualified pharmaceutical-grade suppliers.

Monosodium citrate may create technical work if the reference product depends on a narrow buffer capacity, pH, osmolality, or stability profile. Those technical requirements can increase development cost without creating a durable legal barrier.

What manufacturing and intellectual-property barriers apply?

The principal barriers are operational rather than patent-based.

Manufacturing barriers

A supplier must control neutralization, crystallization, drying, particle size, moisture, and contamination. Pharmaceutical customers may require validated cleaning, controlled environmental conditions, traceability, and formal deviation management.

Intellectual-property barriers

Potentially defensible IP may cover:

• A low-impurity manufacturing route.
• A defined crystalline or hydrated form.
• A particle-size distribution optimized for dissolution.
• A high-purity grade for parenteral formulations.
• A proprietary buffer blend.
• A drug-specific formulation using monosodium citrate.

These rights are narrower than a basic composition patent and may be vulnerable if the claimed process or formulation can be designed around.

How does monosodium citrate compare with other citrate excipients?

Excipient	Primary role	Relative substitution risk	Commercial distinction
Monosodium citrate	Acidic citrate buffer component	Moderate to high	Useful for pH and sodium balance
Disodium citrate	Buffer and pH adjustment	Moderate	Different sodium-to-citrate ratio
Trisodium citrate	Buffer, anticoagulant, chelating agent	Moderate	Common in liquid and blood-related applications
Citric acid	Acidulant and buffer component	High in some formulations	Lower pH and different ionic profile
Phosphate salts	Buffer system	Moderate	Different compatibility and precipitation profile
Acetate salts	Buffer system	Moderate	Alternative pH and metabolic profile

Substitution depends on pH target, buffer capacity, sodium load, solubility, compatibility, taste, osmolality, route of administration, and regulatory precedent.

Key Takeaways

• Monosodium citrate is a mature, low-volume pharmaceutical excipient with limited standalone pricing power.
• No reliable public source isolates global pharmaceutical monosodium citrate revenue.
• Financial performance is linked to citric acid economics, pharmaceutical qualification, and supplier reliability.
• Composition-of-matter patent protection is generally weak or absent.
• Formulation and method-of-use patents may protect finished drug products that use monosodium citrate.
• The FDA regulatory analysis is product-specific and should use the Inactive Ingredient Database, applicable monographs, and finished-product filings.
• Orange Book listings apply to drug products, not to monosodium citrate as an independent excipient.
• Generic-entry risk comes primarily from active-drug patents, formulation complexity, manufacturing controls, and supplier qualification.
• The strongest suppliers compete through quality systems, documentation, regulatory support, dual sourcing, and consistent batch performance.
• The base-case financial trajectory is stable, with limited growth unless the material is adopted in a high-volume injectable, biologic, or platform formulation.

FAQs

Is monosodium citrate the same as trisodium citrate?

No. Monosodium citrate and trisodium citrate have different sodium content, molecular weights, pH behavior, and buffering characteristics. Substitution requires formulation and regulatory assessment.

Can monosodium citrate be used in injectable drugs?

It may be used when the specific grade meets the formulation’s quality, microbial, endotoxin, elemental impurity, and stability requirements. Injectable use must be justified in the finished-product regulatory submission.

Does monosodium citrate have a drug master file?

A supplier may maintain a drug master file or equivalent regulatory package, but DMF availability is manufacturer-specific. A chemical name alone does not establish that a DMF exists.

Is monosodium citrate a high-margin pharmaceutical excipient?

Usually not at the chemical level. Margins improve when the supplier provides validated pharmaceutical-grade material, regulatory support, customized particle properties, dual-site supply, or a proprietary buffer system.

What is the main investment risk in monosodium citrate?

The main risk is commoditization. Customers can often qualify alternative citrate salts or buffer systems, while large chemical producers can compete on scale. The most defensible value lies in qualified supply, documentation, and integration into regulated drug products.

References

1. European Commission. (n.d.). Commission Regulation (EU) No 231/2012 laying down specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008. https://eur-lex.europa.eu/

2. Food and Agriculture Organization of the United Nations & World Health Organization. (n.d.). Compendium of food additive specifications: Sodium dihydrogen citrate. Joint FAO/WHO Expert Committee on Food Additives. https://www.fao.org/food-safety/scientific-advice/jecfa/

3. U.S. Food and Drug Administration. (n.d.-a). Inactive Ingredient Database. https://www.accessdata.fda.gov/scripts/cder/iig/index.cfm

4. U.S. Food and Drug Administration. (n.d.-b). 21 CFR § 182.1751: Sodium citrate. Electronic Code of Federal Regulations. https://www.ecfr.gov/current/title-21/section-182.1751

5. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th edition. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book-data-files

6. United States Pharmacopeial Convention. (n.d.). USP-NF: United States Pharmacopeia and National Formulary. https://www.usp.org/compounding/general-chapter-