List of Excipients in Branded Drug ZINC SULFATE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
American Regent Inc	ZINC SULFATE	zinc sulfate	0517-6103	SULFURIC ACID
American Regent Inc	ZINC SULFATE	zinc sulfate	0517-6103	WATER

Generic Drugs Containing ZINC SULFATE

Company	Ingredient	NDC	Excipient
Camber Pharmaceuticals Inc	zinc sulfate	31722-453	SULFURIC ACID
Camber Pharmaceuticals Inc	zinc sulfate	31722-453	WATER
Apotex Corp	zinc sulfate injection	60505-6260	SULFURIC ACID
Apotex Corp	zinc sulfate injection	60505-6260	WATER

What are the Most Frequently-Used Excipients in ZINC SULFATE?

# Of NDCs	Excipient
10	SULFURIC ACID
10	WATER

Zinc Sulfate Excipient Strategy and Commercial Opportunities

Last updated: July 31, 2026

Zinc sulfate is primarily an active pharmaceutical ingredient, not an excipient. Commercial value comes from selecting the correct zinc sulfate form, controlling elemental-zinc content, and designing a dosage form that solves taste, gastrointestinal tolerability, stability, or parenteral compatibility problems. The strongest opportunities are in oral pediatric products, modified-release supplements, hospital parenteral nutrition, and combination products. Patent protection for zinc sulfate itself is generally weak; differentiation depends on formulation, manufacturing controls, regulatory positioning, and distribution.

What is zinc sulfate used for in pharmaceutical products?

Zinc sulfate supplies zinc as a nutritional or therapeutic mineral. It is available in anhydrous and hydrated forms, most commonly zinc sulfate monohydrate and zinc sulfate heptahydrate. The salt form determines the amount of elemental zinc delivered.

Zinc sulfate form	Approximate elemental zinc content	Primary commercial relevance
Zinc sulfate anhydrous	About 40.5% by weight	High-potency formulations and manufacturing standardization
Zinc sulfate monohydrate	About 36.4% by weight	Tablets, capsules, powders, and oral liquids
Zinc sulfate heptahydrate	About 22.7% by weight	Aqueous processing and selected pharmaceutical applications
Zinc sulfate injection	Product-specific concentration	Total parenteral nutrition and hospital use

The label must state elemental zinc rather than only the mass of zinc sulfate when the product is intended to supplement zinc. FDA labeling for parenteral nutrition products expresses zinc dosing in elemental zinc equivalents and identifies zinc sulfate as the source salt. [1]

Zinc sulfate has high water solubility, an acidic aqueous profile, and a metallic, astringent taste. These properties support injectable and oral-liquid products but create formulation challenges for pediatric and chronic-use products.

What excipient strategy works best for zinc sulfate oral products?

The excipient strategy should be selected around taste, dissolution, gastrointestinal exposure, and elemental-zinc dose.

Tablets and capsules

Immediate-release tablets are the lowest-cost platform. Suitable excipient systems can include:

• Microcrystalline cellulose or dibasic calcium phosphate as diluents
• Crospovidone, croscarmellose sodium, or sodium starch glycolate as disintegrants
• Povidone or hydroxypropyl cellulose as binders
• Colloidal silicon dioxide as a glidant
• Magnesium stearate or sodium stearyl fumarate as lubricants
• Film coatings based on hypromellose, polyvinyl alcohol, or methacrylate polymers

Zinc sulfate is hygroscopic enough to require moisture-control planning. The most important commercial controls are low-moisture excipients, validated granulation conditions, protective film coating, and high-barrier packaging. Aluminum-aluminum blisters or high-density polyethylene bottles with desiccants can reduce moisture uptake.

Direct compression may reduce manufacturing cost, but it can produce poor content uniformity when the zinc sulfate dose is low relative to tablet weight. Wet granulation improves blend uniformity but introduces water and can increase degradation or caking risk. Dry granulation is often a practical compromise for products requiring better flow without aqueous exposure.

Oral liquids

Oral liquids offer the clearest product-development opportunity because zinc sulfate is water soluble. The principal barriers are taste, pH, metal-ion compatibility, and preservative performance.

Potential excipient classes include:

Formulation objective	Excipient approach
Mask metallic taste	Flavor systems, sweeteners, bitterness blockers, and polymeric taste-masking agents
Maintain zinc in solution	pH control, chelating-agent minimization, and controlled ionic strength
Improve palatability	Sucrose, sorbitol, xylitol, glycerin, or high-intensity sweeteners
Control microbial growth	Preservative system validated against the final formulation
Reduce oxidation or color change	Low-oxygen filling, compatible antioxidants, and light-protective packaging
Improve dosing accuracy	Oral syringe-compatible viscosity and calibrated dosing adapter

Chelating excipients require particular scrutiny. Citrate, phosphate, EDTA, and some hydrocolloids can alter zinc speciation, solubility, or bioavailability. A formulation can remain visually clear while changing zinc availability or producing precipitation under dilution conditions. Compatibility testing should cover pH drift, dilution into water or juice, temperature cycling, and contact with dosing devices.

Pediatric liquids can command higher margins than standard tablets when they provide a measurable advantage in taste, dosing accuracy, sugar reduction, or preservative-free packaging. A 10 mL or 15 mL unit-dose sachet can support institutional and travel markets, while multidose bottles are generally more economical for retail use.

Modified-release and gastroprotective products

Modified-release zinc sulfate products are technically feasible but commercially more difficult. Zinc absorption occurs primarily in the small intestine, while high local concentrations can cause nausea and gastric discomfort. Enteric or delayed-release systems may improve tolerability, but they can also alter absorption and create food-effect issues.

Potential technologies include:

• Enteric polymers such as methacrylic acid copolymers
• Hydrophilic matrix systems using hydroxypropyl methylcellulose
• Multiparticulate pellets in capsules
• Lipid or polymeric taste-masking coatings
• Zinc-containing microcapsules for controlled dissolution

The regulatory value of a modified-release product depends on clinical evidence, not only dissolution data. A sponsor seeking a new drug or abbreviated new drug product must establish bioequivalence or therapeutic performance under the applicable FDA pathway. [2]

What formulations are protected by zinc sulfate patents?

Zinc sulfate itself is an old, widely used mineral salt with limited composition-of-matter patent potential. Patent value is more likely to arise from:

1. Taste-masked zinc sulfate particles.
2. Pediatric oral liquids with specific pH and preservative systems.
3. Modified-release or enteric-coated dosage forms.
4. Zinc sulfate combinations with other minerals or active ingredients.
5. Stable premixes for parenteral nutrition.
6. Low-volume concentrated injectable presentations.
7. Manufacturing processes that improve particle size, flow, purity, or dissolution.
8. Device-linked delivery systems and unit-dose packaging.

A formulation patent is stronger when it claims measurable performance rather than a broad list of conventional excipients. Useful claim elements can include:

• A defined elemental-zinc concentration
• A narrow pH range
• Specific zinc sulfate hydration state
• Particle-size distribution
• Dissolution profile
• Stability after storage
• Taste-panel performance
• Reduced precipitation after dilution
• Compatibility with parenteral nutrition components

Broad claims covering zinc sulfate plus a routine tablet excipient are vulnerable to obviousness and enablement challenges. A stronger estate combines formulation claims with process, packaging, and method-of-use claims.

What is the FDA regulatory status of zinc sulfate products?

Regulatory treatment depends on the product category.

Prescription and hospital products

Zinc sulfate injection is used as a trace element component in parenteral nutrition. FDA labeling identifies dosing by patient age, body weight, and clinical condition. Injectable products must meet requirements for sterility, particulate control, endotoxin limits, container closure integrity, and compatibility with parenteral nutrition admixtures. [1]

The main commercial risks are manufacturing quality and hospital procurement pressure rather than active-ingredient exclusivity. A new entrant needs reliable sterile manufacturing, validated aseptic processing, and supply continuity.

Over-the-counter and dietary supplement products

Oral zinc products may be marketed as dietary supplements when they meet the statutory definition under the Dietary Supplement Health and Education Act. Drug claims, disease-treatment claims, and dosage-form positioning can move a product into a different regulatory framework. FDA regulates dietary supplement labeling, manufacturing, and claims under applicable provisions of the Federal Food, Drug, and Cosmetic Act. [3]

The distinction matters commercially. Supplements can reach retail channels quickly but generally have weaker exclusivity and greater price competition. Drug products can support higher regulatory barriers but require a more demanding approval pathway.

FDA Inactive Ingredient Database

Zinc sulfate should not automatically be treated as an inactive ingredient merely because it appears in a formulation. The FDA Inactive Ingredient Database is relevant only where zinc sulfate is functioning as an excipient in an approved drug product. [4] In most zinc sulfate products, it is the active mineral component.

What is the Orange Book status of zinc sulfate?

The Orange Book is product-specific. It lists approved drug products, therapeutic equivalence information, patents, and regulatory exclusivity where applicable. [5]

Zinc sulfate does not have a single Orange Book status covering all tablets, liquids, supplements, and injections. A sponsor must analyze the specific dosage form, strength, route, applicant, and FDA approval pathway. For commercial planning:

• Do not assume that an oral supplement has Orange Book protection.
• Do not assume that an injectable zinc sulfate product has listed patents.
• Confirm whether the reference product is an approved prescription drug rather than a dietary supplement.
• Check patent listings and regulatory exclusivity for the exact reference product and strength.
• Treat formulation, packaging, and manufacturing differences as separate freedom-to-operate questions.

For many zinc sulfate opportunities, the market barrier is abbreviated approval, manufacturing validation, and contracting rather than an active Orange Book patent estate.

When does zinc sulfate lose exclusivity?

Zinc sulfate has no meaningful salt-level exclusivity comparable to a newly approved small-molecule drug. Any exclusivity is likely to attach to a specific approved product, formulation, pediatric study, orphan indication, or delivery technology.

Relevant exclusivity categories may include:

Protection type	Relevance to zinc sulfate
New chemical entity exclusivity	Generally not applicable to zinc sulfate
New clinical investigation exclusivity	Possible for a qualifying approved indication
Pediatric exclusivity	Possible if FDA requirements are satisfied
Orphan-drug exclusivity	Possible only for a qualifying rare-disease indication
Formulation patents	Most commercially relevant
Method-of-use patents	Relevant for defined deficiency or disease-treatment uses
Manufacturing patents	Relevant where purity, particle size, or sterile production is differentiated
Trade secrets	Important for taste masking, process controls, and stability packages

Patent term generally runs 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, terminal disclaimers, and possible patent-term extension. [6] For an old mineral salt, newly filed patents will typically protect a later-developed formulation or use rather than zinc sulfate itself.

What generic entry risks exist for zinc sulfate products?

Generic entry risk is high for conventional immediate-release products and lower for technically differentiated products.

High-risk products

• Standard tablets and capsules
• Unflavored oral powders
• Simple zinc sulfate solutions
• Products using broadly available excipients
• Products sold primarily through commodity hospital contracts

Moderate-risk products

• Sugar-free pediatric liquids
• Low-volume unit-dose liquids
• Products with validated taste masking
• Zinc sulfate in combination with other minerals
• Stable concentrated parenteral presentations

Lower near-term substitution risk

• Complex multiparticulate systems
• Clinically supported modified-release products
• Products with device integration
• Sterile products requiring specialized filling
• Products with difficult-to-reproduce stability or compatibility performance

Paragraph IV challenges are most relevant where an approved prescription reference product has listed patents. A challenger can contest listed patents by certifying that the patent is invalid, unenforceable, or will not be infringed. [5] For zinc sulfate, the practical value of a Paragraph IV strategy depends on whether the reference product has meaningful listed patents and whether the proposed generic copies the protected formulation.

Which companies are challenging zinc sulfate products?

The zinc sulfate market is fragmented across generic-drug manufacturers, hospital suppliers, dietary supplement companies, contract manufacturers, and mineral-ingredient producers. Unlike major branded medicines, the market does not generally center on a single innovator with a large, visible patent litigation program.

Competitive analysis should segment companies by product type:

Segment	Competitive basis
Injectable suppliers	Sterile manufacturing, hospital contracts, shortage resilience
Generic oral-drug manufacturers	Cost, ANDA execution, scale, wholesaler access
Supplement manufacturers	Retail distribution, claims compliance, branding
Pediatric formulation specialists	Taste masking, dosing systems, clinical usability
Ingredient suppliers	Purity, hydration state, particle size, documentation
Contract development and manufacturing organizations	Formulation know-how and regulatory support

Public litigation searches should cover the FDA Orange Book, PACER, district court dockets, PTAB proceedings, and patent-family databases. The most relevant disputes are likely to concern formulation or manufacturing claims rather than ownership of zinc sulfate as a chemical substance.

How strong is the patent estate for zinc sulfate?

The core patent estate is weak. The opportunity lies in building a layered, product-specific estate.

A commercially useful portfolio could include:

1. Composition claims covering a taste-masked zinc sulfate particle.
2. Dosage-form claims covering a pediatric liquid with defined pH, viscosity, and stability.
3. Process claims covering granulation, coating, or sterile filling.
4. Packaging claims covering moisture-protective or unit-dose delivery.
5. Method claims directed to a defined deficiency population.
6. Continuation applications preserving claim scope across dosage forms.

Patent strength depends on comparative data. A sponsor should generate evidence showing improved palatability, lower nausea, reduced precipitation, longer shelf life, better content uniformity, or superior manufacturing yield against conventional zinc sulfate products.

Trade-secret protection can be more valuable than patent protection for flavor systems, coating parameters, blending order, and sterile manufacturing controls. The trade-off is that process secrets may be difficult to enforce if the final product does not reveal the method.

What are the largest commercial opportunities for zinc sulfate?

Pediatric oral liquids

Taste-masked, sugar-free, alcohol-free zinc sulfate liquids can address administration barriers in children. Product value increases with dosing accuracy, stable shelf life, and compatibility with oral syringes.

Hospital parenteral nutrition

Injectable zinc sulfate is a supply-chain product. Opportunities include ready-to-use presentations, standardized concentrations, low-volume containers, and reliable availability during injectable shortages. FDA drug-shortage data and hospital purchasing records should guide target presentations. [7]

Combination mineral products

Zinc sulfate can be combined with copper, selenium, magnesium, or other nutrients. The technical challenge is preventing precipitation, oxidation, and dose nonuniformity. Combination products can reduce pill burden but require broader stability and interaction testing.

Modified-release supplements

A formulation that reduces gastrointestinal discomfort while maintaining zinc absorption can command a premium. Clinical support is important because delayed dissolution alone does not establish a consumer or therapeutic advantage.

High-purity pharmaceutical-grade ingredients

Manufacturers can differentiate through low heavy-metal content, controlled hydration state, tight particle-size distribution, low endotoxin levels, and stronger regulatory documentation. These attributes matter most for injectable and pediatric applications.

How does zinc sulfate compare with other zinc salts?

Zinc salt	Approximate elemental zinc content	Formulation profile
Zinc sulfate monohydrate	About 36%	Low cost, water soluble, metallic taste
Zinc sulfate heptahydrate	About 23%	Water soluble, lower elemental-zinc density
Zinc gluconate	About 14%	Common supplement salt, generally better consumer familiarity
Zinc acetate	About 30%	Water soluble, used in selected oral products
Zinc oxide	About 80%	High elemental zinc, low water solubility
Zinc picolinate	Product-dependent	Premium supplement positioning, higher ingredient cost

Zinc sulfate is strongest where water solubility, low raw-material cost, and injectable use matter. Zinc oxide is stronger for high elemental-zinc loading but is poorly soluble. Zinc gluconate and zinc acetate may be easier to position in consumer products where taste and market familiarity are priorities.

Key Takeaways

• Zinc sulfate is usually the active ingredient, not the excipient.
• The best excipient opportunities involve taste masking, moisture control, pH management, and parenteral compatibility.
• Conventional zinc sulfate tablets have high generic and price-substitution risk.
• Pediatric liquids, sterile injections, modified-release products, and combination minerals offer stronger commercial differentiation.
• Zinc sulfate has limited composition-of-matter patent value.
• Formulation, process, packaging, and method-of-use patents are the principal intellectual-property routes.
• Orange Book and Paragraph IV analysis must be performed for the exact approved product, strength, route, and applicant.
• Manufacturing reliability and regulatory documentation can create more commercial value than a broad patent claim.
• Zinc sulfate monohydrate is generally more attractive for oral solid products; injectable products require product-specific control of concentration, purity, sterility, and compatibility.
• A differentiated product should generate comparative data on taste, stability, dissolution, precipitation, content uniformity, or clinical tolerability.

FAQs

Is zinc sulfate an active ingredient or an excipient?

In most pharmaceutical and supplement products, zinc sulfate is the active mineral ingredient. It is an excipient only when used for a nontherapeutic formulation function in another product.

Which zinc sulfate form is best for oral tablets?

Zinc sulfate monohydrate is often practical because it combines meaningful elemental-zinc content with good water solubility and broad formulation utility. The final selection depends on assay, moisture sensitivity, particle size, and supplier controls.

Can zinc sulfate be used in pediatric oral suspensions?

Yes. Zinc sulfate can be formulated as an oral solution or suspension, but taste masking, dose uniformity, preservative efficacy, pH, and compatibility with dosing devices require validation.

Are zinc sulfate products eligible for Paragraph IV litigation?

Only an approved drug product with relevant listed patents creates a conventional Paragraph IV pathway. Many zinc sulfate supplements and commodity products do not provide that litigation structure.

What is the most defensible zinc sulfate patent strategy?

The strongest approach combines claims directed to a measurable formulation benefit with process, packaging, and method-of-use claims. Taste masking, stability, controlled release, and sterile compatibility are more defensible than broad claims covering zinc sulfate with routine excipients.

References

1. U.S. Food and Drug Administration. (n.d.). Zinc sulfate injection prescribing information. DailyMed. https://dailymed.nlm.nih.gov/

2. U.S. Food and Drug Administration. (2013). Guidance for industry: Bioequivalence studies with pharmacokinetic endpoints for drugs submitted under an ANDA. https://www.fda.gov/

3. U.S. Food and Drug Administration. (n.d.). Dietary supplements. https://www.fda.gov/food/dietary-supplements

4. U.S. Food and Drug Administration. (n.d.). Inactive ingredient database. https://www.accessdata.fda.gov/scripts/cder/iig/

5. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book

6. United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term. https://www.uspto.gov/

7. U.S. Food and Drug Administration. (n.d.). Drug shortages. https://www.fda.gov/drugs/drug-safety-and-availability/drug-shortages