List of Excipients in Branded Drug PAROMOMYCIN SULFATE

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Generic Drugs Containing PAROMOMYCIN SULFATE

Company	Ingredient	NDC	Excipient
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	D&C RED NO. 28
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	D&C YELLOW NO. 10
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	FD&C BLUE NO. 1
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	FD&C BLUE NO. 2
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	FD&C RED NO. 40
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	FERROSOFERRIC OXIDE
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	paromomycin sulfate	23155-038	GELATIN

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

# Of NDCs	Excipient
3	D&C RED NO. 28
3	D&C YELLOW NO. 10
3	FD&C BLUE NO. 1
3	FD&C BLUE NO. 2
3	FD&C RED NO. 40
3	FERROSOFERRIC OXIDE
3	GELATIN

Paromomycin Sulfate Excipient Strategy and Commercial Opportunities

Last updated: October 22, 2026

Paromomycin sulfate is an old aminoglycoside with low oral absorption, established activity against intestinal parasites, and limited conventional patent protection. The strongest commercial opportunities are differentiated oral products, pediatric and liquid formulations, global-health supply, and new delivery systems for leishmaniasis and other infections. Excipient selection should focus on dose uniformity, moisture control, palatability, sulfate-salt compatibility, and scalable manufacturing rather than on novel chemical protection of the active ingredient.

What is the FDA regulatory status of paromomycin sulfate?

Paromomycin sulfate is an FDA-approved aminoglycoside antibiotic marketed in the United States as oral capsules under the Humatin brand and through generic products.

Regulatory attribute	Status
Active ingredient	Paromomycin sulfate
Drug class	Aminoglycoside antibiotic
Main U.S. dosage form	250 mg oral capsule
Primary approved use	Intestinal amebiasis
FDA pathway	Abbreviated New Drug Application for generic products; 505(b)(2) may apply to reformulated or repurposed products
Oral bioavailability	Low, allowing local intestinal activity
U.S. reference product	Humatin capsules
Biosimilar pathway	Not applicable
Orange Book relevance	Relevant for approved drug products and any listed patents or exclusivity
Prescription status	Prescription drug

The commercial value of oral paromomycin comes from its limited gastrointestinal absorption. The drug can reach high intestinal concentrations while producing less systemic exposure than many parenteral aminoglycosides. The same property creates a formulation challenge: the product must disintegrate and release drug reliably in the intestinal lumen without unnecessarily increasing systemic absorption.

Paromomycin sulfate is also used internationally for visceral leishmaniasis, generally by intramuscular injection, although regulatory status varies by country. WHO identifies paromomycin as an important medicine for selected infectious diseases and neglected tropical disease programs. [1]

What excipients are used in paromomycin sulfate capsules?

The Humatin label identifies a conventional hard-gelatin capsule platform. Public labeling has identified excipients including lactose, starch, magnesium stearate, gelatin, and capsule colorants. Exact excipient composition can vary by manufacturer and must be verified against the current product label and approved application. [2]

Core formulation functions

Formulation component	Commercial purpose	Key technical consideration
Lactose or another filler	Provides capsule bulk and improves fill-weight control	Assess lactose intolerance, reducing sugars, and moisture exposure
Pregelatinized starch or corn starch	Improves powder packing and capsule disintegration	Control swelling, flow, and batch-to-batch variability
Magnesium stearate	Reduces sticking and improves encapsulation	Excessive lubrication can slow wetting and dissolution
Colloidal silicon dioxide	Improves flow in high-dose powder blends	Can reduce cohesion but may alter powder density
Gelatin capsule shell	Standard oral presentation	Moisture migration and brittleness require packaging control
Titanium dioxide and colorants	Product identification and branding	Regulatory restrictions differ by jurisdiction
Crospovidone or croscarmellose sodium	Faster disintegration in an enhanced capsule	Useful where dissolution or high-dose compacting is a problem
Mannitol or microcrystalline cellulose	Lactose-free or pediatric-oriented alternative	May improve mouthfeel or powder handling

The active dose is high relative to many oral medicines. A 250 mg paromomycin-equivalent capsule contains a substantially larger mass of sulfate salt than a highly potent small molecule. This makes excipient selection a manufacturing issue, not only a patient-experience issue.

A practical first-generation formula would use a direct-fill blend based on a filler, starch-based disintegrant, glidant, and low-level lubricant. Wet granulation should be reserved for products with inadequate flow, poor content uniformity, or unacceptable capsule-fill variability. Water exposure during granulation requires careful control because the product is a sulfate salt and the finished capsule must remain stable under humid conditions.

What excipient strategy is best for a differentiated paromomycin product?

The strongest strategy is to select excipients according to the target market rather than to copy the legacy capsule.

Adult oral capsule

For adult intestinal amebiasis, the lowest-risk development path is a hard capsule with:

• lactose-free filler options where required;
• a robust disintegrant system;
• low lubricant concentration;
• high-density powder engineering to reduce capsule size;
• moisture-protective blister packaging;
• visible capsule identification for multi-day dosing.

A lactose-free product could expand procurement eligibility in hospitals and public-health tenders. Mannitol, microcrystalline cellulose, dibasic calcium phosphate, or combinations of these materials can replace lactose, subject to compatibility and dissolution testing.

Pediatric oral suspension

A pediatric product is the clearest unmet formulation opportunity. Capsules are poorly suited to young children, and paromomycin regimens can require multiple daily doses over several days.

A dry powder for reconstitution could provide:

• weight-based dosing;
• improved administration for children;
• lower shipping weight than a ready-to-use suspension;
• longer shelf life before reconstitution;
• compatibility with oral syringes.

The main challenges are the sulfate salt's taste, sedimentation, redispersibility, microbial control after reconstitution, and stability in the presence of water. A suspension would likely require a structured vehicle using a suspending polymer such as xanthan gum, sodium carboxymethylcellulose, or microcrystalline cellulose with carboxymethylcellulose sodium. A sweetener and flavor system would be required, but taste-masking should not compromise dose uniformity.

Enteric or delayed-release dosage form

Enteric coating is not automatically advantageous. Paromomycin is intended to act in the intestinal tract, so delaying release until the ileum or colon could reduce exposure in the upper intestine and may narrow the effective treatment window.

A delayed-release product could have value for targeted colonic delivery, recurrent intestinal infection, or microbiome-directed applications. The commercial case would require clinical evidence that location-specific release improves efficacy, tolerability, or dosing convenience.

Sachets and dispersible tablets

Single-dose powder sachets could support low-resource settings, field deployment, and institutional procurement. Dispersible tablets may offer better portability than liquid products but would need to manage the high mass of paromomycin sulfate per dose.

Effervescent systems are less attractive because moisture sensitivity, high excipient load, and packaging costs can increase complexity without creating a clear therapeutic advantage.

What formulations are protected by paromomycin patents?

The original paromomycin compound is old and is not expected to provide meaningful modern composition-of-matter exclusivity. Commercial protection is more likely to arise from:

1. pediatric suspension technology;
2. taste-masked oral dosage forms;
3. enteric or site-specific delivery;
4. topical delivery for cutaneous or mucosal infection;
5. injectable formulations with improved stability;
6. combination products;
7. manufacturing processes that improve purity or control sulfate stoichiometry;
8. method-of-use claims for diseases outside the legacy label.

A formulation patent must show more than the selection of a routine excipient. Stronger claim positions would require a defined excipient ratio, measurable release profile, stability advantage, improved palatability, reduced dosing burden, or clinical benefit.

U.S. Orange Book exposure should be assessed product by product. For an old generic drug such as paromomycin sulfate, the principal regulatory risk is usually not an active ingredient patent but the possibility that a newly approved reference or reformulated product lists a formulation or method-of-use patent. The Orange Book does not capture every patent relevant to commercial freedom to operate, particularly patents covering manufacturing processes, foreign products, or unapproved uses. [3]

When does paromomycin sulfate lose exclusivity?

Paromomycin sulfate lost practical composition-of-matter exclusivity decades ago. The relevant commercial question is whether a particular branded or reformulated product has current regulatory exclusivity or listed patent protection.

Exclusivity category	Expected position for legacy oral paromomycin
New chemical entity exclusivity	Expired or unavailable
Orphan-drug exclusivity	Product- and indication-specific; not inherent to paromomycin
Pediatric exclusivity	Not inherent to the API
New formulation exclusivity	Possible only for a qualifying new approval
Method-of-use exclusivity	Possible for a newly approved indication
Generic competition	Established or commercially feasible
Biosimilar competition	Not relevant

A developer seeking protection would need to create a new FDA-recognized product or indication. A new oral suspension, long-acting injectable, or targeted delivery product could potentially support regulatory exclusivity if it meets the applicable statutory criteria. The protection would attach to the approved product or indication, not to paromomycin sulfate generally.

What Paragraph IV challenges and patent litigation affect paromomycin?

Paromomycin does not have the high-profile Paragraph IV litigation profile associated with newer specialty drugs. Generic applicants could use an ANDA certification strategy if an Orange Book-listed patent covered a reference product. In the absence of an unexpired listed patent, the principal barriers are product development, bioequivalence, manufacturing validation, and market economics.

Risk area	Assessment
Paragraph IV litigation	Low for legacy capsules unless a current listed patent is identified
ANDA filing risk	Moderate from a technical and commercial standpoint
Formulation patent risk	Higher for novel suspensions, delayed-release products, and delivery systems
Process patent risk	Relevant where a supplier relies on a proprietary purification or crystallization process
Product-liability risk	Relevant because aminoglycosides can cause nephrotoxicity and ototoxicity under systemic exposure
Supply-chain risk	Material because the market is relatively small and supplier concentration can affect continuity

No major settlement framework comparable to high-value branded products should be assumed for legacy paromomycin capsules. Any settlement involving a particular product would need to be verified through court records, FDA records, and the relevant patent docket.

How strong is the paromomycin sulfate patent estate?

The patent estate is weak for the unmodified API and potentially moderate for engineered products.

Weak protection areas

• conventional 250 mg capsules;
• standard lactose-starch-magnesium stearate blends;
• routine powder filling;
• ordinary packaging changes;
• broad claims to treating intestinal amebiasis with known paromomycin.

Stronger protection areas

• stable pediatric liquid formulations;
• demonstrated taste masking;
• site-specific release with clinical support;
• novel topical or transdermal delivery;
• long-acting injectable depots;
• combination regimens with defined synergistic effects;
• manufacturing processes that solve a reproducible impurity or crystallinity problem.

The best intellectual-property strategy is a layered portfolio. One patent should not carry the entire commercial case. A developer would seek composition claims for the dosage form, process claims for manufacture, method-of-use claims for a differentiated indication, and regulatory exclusivity where available.

What commercial opportunities exist for paromomycin sulfate?

Generic oral capsules

The capsule market is a low-price, low-growth opportunity. Its advantages are simple manufacturing and established clinical use. Its disadvantages are limited differentiation, price competition, small demand, and potential procurement concentration.

Pediatric products

A pediatric suspension or dispersible dosage form has stronger commercial logic. Hospitals, tropical-medicine programs, and international procurement agencies may value accurate weight-based administration and reduced dependence on capsule manipulation.

Neglected tropical disease supply

Paromomycin has commercial relevance in visceral leishmaniasis programs, particularly in countries where intramuscular therapy is used. The opportunity is often tender-driven rather than retail-driven. Winning factors include:

• WHO or national-program acceptance;
• stable supply;
• low unit cost;
• reliable cold-chain independence;
• multilingual labeling;
• pharmacovigilance capability;
• local registration.

Leishmaniasis delivery systems

An improved injectable product could target reduced injection burden, improved storage stability, or better tolerability. Depot formulations and combination products have greater technical and regulatory risk than conventional injection, but they offer more defensible intellectual property.

Topical and mucosal products

Topical paromomycin has been investigated for cutaneous leishmaniasis and other localized infections. A cream, gel, or mucoadhesive formulation could create a separate product category. The main challenges are local tolerability, penetration into infected tissue, treatment duration, and proof that the formulation improves outcomes over existing therapy.

Veterinary applications

Paromomycin has potential veterinary relevance, but regulatory requirements, residue controls, antimicrobial-stewardship policies, and market fragmentation can reduce attractiveness. A veterinary product requires a separate assessment of target species, food-animal restrictions, withdrawal periods, and local approvals.

How does paromomycin compare with competing anti-infective opportunities?

Product opportunity	Patent potential	Clinical differentiation	Commercial attractiveness
Generic paromomycin capsule	Low	Low	Low to moderate
Pediatric oral suspension	Moderate	Moderate	Moderate to high
Dispersible tablet	Moderate	Moderate	Moderate
Delayed-release capsule	Moderate to high	Moderate	Moderate
Long-acting injectable	High	High	High but technically difficult
Topical leishmaniasis product	Moderate to high	High in selected markets	Moderate
Combination product	Moderate	High if clinically validated	Moderate to high
Veterinary formulation	Moderate	Variable	Market-specific

What generic launch scenarios exist?

Scenario 1: Conventional generic capsule

The launch would rely on ANDA approval, supply reliability, and competitive pricing. The likely market share would depend heavily on wholesaler access and public-sector purchasing.

Scenario 2: Differentiated pediatric product

A 505(b)(2) or equivalent reformulation strategy could support a liquid or dispersible product. The developer would need comparative stability, dosing accuracy, palatability, and clinical or regulatory justification for the new presentation.

Scenario 3: Global-health tender product

A manufacturer could target procurement agencies with a low-cost capsule or injection. The product would need regulatory approvals in endemic markets and a manufacturing platform capable of maintaining supply during tender cycles.

Scenario 4: Specialty delivery product

A topical, depot, or targeted intestinal product could pursue higher pricing and stronger patent protection. This scenario carries the highest development and clinical risk.

What manufacturing and IP barriers affect paromomycin sulfate?

The main manufacturing barriers are process consistency and economics rather than access to a rare chemical structure.

Key technical controls include:

• sulfate stoichiometry;
• water content;
• related substances;
• microbiological quality;
• powder flow;
• capsule-fill weight;
• dissolution and disintegration;
• residual solvents from API manufacture;
• extractables and leachables from packaging;
• stability under high humidity.

The supply chain should include qualified API suppliers, dual-source risk analysis, and controls for aminoglycoside impurity profiles. For global-health products, packaging must tolerate high-temperature and high-humidity distribution.

What are the revenue opportunities and exposure?

Public revenue data for paromomycin are limited because sales are distributed across generic manufacturers, tenders, hospital channels, and international programs. The commercial exposure is generally modest compared with large branded anti-infectives.

The most defensible revenue pools are:

1. pediatric formulations with limited direct competition;
2. institutional and public-health tenders;
3. approved injectable supply for visceral leishmaniasis;
4. specialty topical products;
5. combination therapies with differentiated clinical positioning.

A conventional capsule is unlikely to support significant premium pricing. A formulation that reduces dosing errors, improves adherence, or removes the need for capsule opening has a clearer value proposition.

Key Takeaways

• Paromomycin sulfate has little remaining composition-of-matter value but retains formulation and delivery opportunities.
• The strongest near-term excipient opportunity is a lactose-free pediatric suspension or dispersible product.
• A conventional capsule should use a simple, moisture-controlled powder blend with reliable disintegration and low lubricant loading.
• Enteric coating requires clinical justification because the drug already acts in the intestinal tract.
• Global-health and visceral-leishmaniasis markets are procurement-driven and depend on supply reliability, registration, and price.
• Biosimilar risk is irrelevant; generic and reformulation competition are the relevant threats.
• Patent strength is likely to be low for standard capsules and higher for validated taste masking, site-specific delivery, depot injection, topical systems, and combination products.
• Revenue potential is limited for undifferentiated capsules but can improve materially with pediatric, specialty, or tender-focused products.

FAQs

Is paromomycin sulfate suitable for an oral liquid?

Yes. A dry powder for reconstitution is more practical than a ready-to-use liquid because it can improve shelf life and reduce microbial-stability problems. Taste masking, sedimentation control, and post-reconstitution stability are the principal development issues.

Can paromomycin sulfate be formulated as an enteric-coated capsule?

Yes, but the commercial rationale must be demonstrated. Enteric coating may support targeted colonic delivery, but it can also delay release in a way that reduces therapeutic exposure.

Does paromomycin sulfate have biosimilar competition?

No. Paromomycin sulfate is a conventional small-molecule drug. Competition occurs through generic drugs, reformulations, and potentially new drug applications, not biosimilar applications.

Is a paromomycin sulfate topical product commercially viable?

Potentially, particularly for localized leishmaniasis or other infections where local drug delivery could reduce systemic exposure. The product would need clinical evidence of penetration, tolerability, and improved treatment performance.

What is the best patent strategy for a new paromomycin product?

The strongest strategy combines a defined dosage-form composition, manufacturing claims, method-of-use claims, and regulatory exclusivity where available. Claims limited to routine excipient substitution are less defensible.

References

1. World Health Organization. (2023). WHO model list of essential medicines: 23rd list. Geneva, Switzerland: World Health Organization.

2. DailyMed. (n.d.). Humatin and paromomycin sulfate capsule prescribing information. U.S. National Library of Medicine.

3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. Silver Spring, MD: U.S. Food and Drug Administration.

4. U.S. Food and Drug Administration. (2023). Approved drug products and abbreviated new drug application regulatory requirements. Silver Spring, MD: U.S. Food and Drug Administration.

5. U.S. Food and Drug Administration. (2017). Guidance for industry: ANDAs for certain highly purified synthetic peptides. Silver Spring, MD: U.S. Food and Drug Administration.