List of Excipients in Branded Drug ATOVAQUONE ORAL SUSPENSION

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Generic Drugs Containing ATOVAQUONE ORAL SUSPENSION

Company	Ingredient	NDC	Excipient
KVK-Tech Inc	atovaquone	10702-223	BENZYL ALCOHOL
KVK-Tech Inc	atovaquone	10702-223	POLOXAMER 188
KVK-Tech Inc	atovaquone	10702-223	SACCHARIN SODIUM
KVK-Tech Inc	atovaquone	10702-223	WATER
KVK-Tech Inc	atovaquone	10702-223	XANTHAN GUM

What are the Most Frequently-Used Excipients in ATOVAQUONE ORAL SUSPENSION?

# Of NDCs	Excipient
2	BENZYL ALCOHOL
2	POLOXAMER 188
2	SACCHARIN SODIUM
2	WATER
2	XANTHAN GUM

Atovaquone Oral Suspension Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: October 25, 2026

Atovaquone oral suspension is a mature, off-patent pharmaceutical product with continuing demand in Pneumocystis jirovecii pneumonia prophylaxis and treatment, toxoplasmosis prophylaxis, and malaria prevention and treatment. The principal commercial opportunity is not a new active ingredient. It is a better-performing suspension with improved palatability, redispersibility, dose accuracy, storage flexibility, and cost of goods.

The reference product, Mepron, contains atovaquone at 750 mg per 5 mL and uses a conventional aqueous suspension platform with micronized drug, poloxamer 188, xanthan gum, saccharin sodium, benzyl alcohol, flavoring, and water-based excipients.[1,2] The formulation is technically difficult because atovaquone has very low aqueous solubility and absorption depends substantially on administration with food.[1,3]

What is atovaquone oral suspension used for?

Atovaquone oral suspension is used for several infectious-disease indications:

Indication	Typical commercial relevance	Key formulation consideration
Prevention of Pneumocystis jirovecii pneumonia	High	Long-duration use, palatability, adherence
Treatment of mild-to-moderate Pneumocystis jirovecii pneumonia	Moderate	High dose, accurate administration
Prevention of toxoplasmosis in selected patients	Moderate	Chronic dosing and tolerability
Treatment or prevention of malaria in combination regimens	Variable	Geographic access, portability, taste
Pediatric or swallowing-impaired populations	High strategic value	Dosing flexibility and oral acceptability

The approved product is particularly relevant for patients who cannot tolerate trimethoprim-sulfamethoxazole or who require an alternative because of sulfonamide allergy, hematologic toxicity, renal concerns, or drug-interaction considerations.[1]

What excipients are used in atovaquone oral suspension?

The reference formulation uses a small excipient system designed to wet, suspend, preserve, sweeten, and mask the taste of micronized atovaquone.

Excipient or component	Primary function	Commercial and technical role
Micronized atovaquone	Active pharmaceutical ingredient	Controls dissolution, sedimentation, and dose uniformity
Poloxamer 188	Wetting and dispersing agent	Improves particle wetting and suspension uniformity
Xanthan gum	Suspending and viscosity-building agent	Limits sedimentation and supports redispersion
Benzyl alcohol	Preservative	Controls microbial growth in a multidose aqueous product
Saccharin sodium	Sweetener	Masks bitterness and improves acceptability
Flavor	Taste masking	Reduces aversion during repeated dosing
Purified water	Vehicle	Provides the continuous aqueous phase

The principal formulation constraint is that the drug must remain physically dispersed rather than dissolved. Excessive viscosity can impair pouring and oral syringe withdrawal. Insufficient viscosity can cause rapid settling, caking, and dose variability.

How does atovaquone’s physicochemical profile affect formulation design?

Atovaquone is a poorly water-soluble hydroxynaphthoquinone. Its limited aqueous solubility makes conventional solution formulations impractical at the approved concentration.[1,3] The commercial product therefore relies on micronization and suspension stabilization.

Three properties drive formulation performance:

1. Low aqueous solubility limits dissolution rate and systemic exposure.
2. Hydrophobic particle surfaces create wetting and aggregation challenges.
3. High drug loading increases the risk of sedimentation, caking, and dose nonuniformity.

Particle-size distribution is a critical quality attribute. Smaller particles can improve dissolution and reduce settling velocity, but excessive milling can increase surface energy, agglomeration, electrostatic charging, and processing complexity. The target is not the smallest possible particle. It is a reproducible particle population with acceptable dissolution, suspendability, and manufacturing robustness.

Food effect is also central. The label reports higher exposure when atovaquone is administered with food, particularly meals containing dietary fat.[1] A formulation cannot fully eliminate the clinical impact of food intake without materially changing the drug-delivery system. Excipient selection should therefore improve dispersion and reproducibility while preserving the approved dose and route.

What excipient strategies can improve atovaquone suspension performance?

Wetting and dispersion systems

Poloxamer 188 is a logical wetting agent because it can improve contact between hydrophobic drug particles and the aqueous vehicle. Alternative surfactants may include polysorbates, sodium lauryl sulfate at low levels, poloxamer grades with different molecular weights, or nonionic surfactant combinations.

Each alternative creates regulatory and performance tradeoffs:

• Polysorbates can support wetting but may introduce oxidative degradation concerns.
• Sodium lauryl sulfate can improve wetting but may create taste and irritation issues.
• Higher surfactant loading can increase foaming and complicate manufacturing.
• Surfactant selection can affect particle size during milling and long-term suspension stability.

A differentiated formulation should demonstrate improved redispersion and dissolution without increasing gastrointestinal tolerability issues.

Suspending agents

Xanthan gum is established in oral suspensions and provides shear-thinning behavior. The product can remain viscous at rest while becoming easier to pour or withdraw under shear.

Potential alternatives include:

• Microcrystalline cellulose and carboxymethylcellulose combinations
• Hydroxypropyl methylcellulose
• Sodium carboxymethylcellulose
• Polyacrylic acid systems
• Guar gum or other natural hydrocolloids

The most valuable property is controlled sedimentation with rapid redispersion. A suspension that remains physically stable but requires vigorous shaking for more than several seconds can still create dosing problems in pediatric and home-care settings.

Taste-masking systems

Atovaquone is described as having an unpleasant taste. Sweetener and flavor selection is therefore commercially important, particularly for long-term prophylaxis and pediatric use.

Potential approaches include:

• Sucrose or polyol-based sweetness systems
• Sucralose, acesulfame potassium, or neotame combinations
• Fruit flavors with acidulant adjustment
• Ion-exchange resin complexes
• Polymer coating of drug particles
• Lipid or self-emulsifying taste-masking systems

A taste-masking platform must not materially delay drug release or reduce exposure. Coated particles can create dissolution risk if the coating is too hydrophobic or dense. Sweetener systems also affect viscosity, osmolality, preservative efficacy, and microbial risk.

Preservative alternatives

The reference product uses benzyl alcohol. A commercial alternative could use another preservative system, but the regulatory and safety rationale must be strong.

Potential alternatives include:

• Potassium sorbate
• Sodium benzoate
• Parabens
• Phenoxyethanol
• Organic-acid preservation systems

Benzyl alcohol may be undesirable in certain neonatal or highly vulnerable populations. A preservative-free multidose product would be commercially attractive but technically difficult. It would require robust container-closure performance, microbial challenge data, in-use stability, and potentially a single-dose or unit-dose presentation.

What formulations are protected by atovaquone patents?

Atovaquone’s original compound and early pharmaceutical patent protection have expired. The commercial opportunity is therefore primarily a formulation, process, device, or presentation strategy rather than composition-of-matter exclusivity.

Protection category	Current commercial relevance
Atovaquone compound patents	Expired
Original oral suspension patents	Generally expired or commercially exhausted
Formulation patents	Possible only where a later patent claims a specific composition or process
Method-of-use patents	Limited value for established labeled indications
Manufacturing-process patents	Potentially relevant for particle engineering and scale-up
Device or container patents	Potentially relevant for oral syringes, unit doses, or closure systems
Trade secrets	Important for milling, dispersion order, and process controls

The FDA Orange Book is the controlling source for patents listed against approved innovator products. Mepron’s commercial exclusivity is not currently dependent on a composition-of-matter patent. Generic applicants can generally pursue abbreviated approval through the ANDA pathway, subject to any live listed patent or regulatory exclusivity applicable to the reference product.[4]

When does atovaquone oral suspension lose exclusivity?

The core exclusivity period for atovaquone oral suspension has passed. Mepron received FDA approval in the early 1990s, and generic competition has entered the U.S. market.[1,4]

Milestone	Status
U.S. reference product	Mepron
Active ingredient	Atovaquone
Dosage form	Oral suspension
Strength	750 mg/5 mL
Approval era	Early 1990s
New chemical entity exclusivity	Expired
Core patent estate	Expired
Generic pathway	ANDA
Current commercial focus	Price, supply, formulation quality, and channel access

The absence of meaningful core exclusivity does not eliminate legal risk. A later-listed formulation patent, manufacturing patent, or use patent could affect a particular generic filing. The practical risk is usually lower than in protected small-molecule markets because multiple manufacturers can develop substantially similar suspensions using established excipients.

How many patents cover atovaquone oral suspension?

The commercially relevant patent count is limited compared with newer branded drugs. The central patent barriers have expired, and the market is characterized by generic formulation competition rather than active ingredient exclusivity.

Patent diligence should separate:

1. Expired compound patents.
2. Expired Mepron formulation patents.
3. Any live patents listed in the Orange Book.
4. Unlisted patents that could support a separate infringement action.
5. Process patents covering micronization, particle engineering, or manufacturing.
6. Container, dosing-device, or packaging claims.

A patent number should not be treated as commercially blocking solely because it appears in a family or prosecution record. Claim scope, expiration, terminal disclaimers, maintenance status, listed use codes, and applicability to the proposed formulation determine the actual risk.

What is the Orange Book status of Mepron?

Mepron is the reference listed drug for atovaquone oral suspension in the United States. Its product and approval information are maintained in FDA’s Drugs@FDA and Orange Book databases.[4,5]

The relevant regulatory pathway is an ANDA referencing the approved atovaquone oral suspension. A generic applicant must demonstrate pharmaceutical equivalence and bioequivalence, along with quality, stability, microbiological, and manufacturing controls.

The product is not a biologic. Biosimilar approval is therefore irrelevant. Competitive entry occurs through the generic drug pathway, not through a 351(k) application.

Which companies are challenging or competing with Mepron?

Competition has come from generic manufacturers rather than biosimilar developers. Generic participation can vary by country and over time because the product has relatively modest volume, specialized indications, and supply-chain sensitivity.

The competitive set can include:

• Generic manufacturers with approved atovaquone oral suspension ANDAs
• Contract manufacturers supplying private-label products
• International manufacturers supplying malaria and HIV channels
• Innovator or specialty distributors retaining branded inventory
• Compounding pharmacies in limited settings where approved products are unavailable

The strongest competitive advantages are usually manufacturing reliability, competitive pricing, hospital contracting, government procurement eligibility, and consistent supply. A new entrant with no meaningful formulation differentiation may face rapid price compression.

What generic entry risks exist for atovaquone oral suspension?

Generic entry risk is high from a legal perspective because the product is mature and the core exclusivity period has ended. Commercial entry risk is more balanced.

Risk	Assessment
Paragraph IV challenge to core patents	Low where no blocking patents remain
Formulation equivalence	Moderate
Bioequivalence	Moderate because food affects exposure
Content uniformity	Moderate to high
Physical stability	Moderate
Taste acceptance	Moderate
Supply economics	Moderate to high
Regulatory failure	Moderate if suspension controls are weak
Price erosion	High after multiple entrants

What is a Paragraph IV challenge?

A Paragraph IV certification states that a patent listed for the reference product is invalid, unenforceable, or will not be infringed by the proposed generic product. If no material listed patent remains, an applicant may use a different certification pathway. Where a patent is listed, the certification can trigger patent litigation and a potential 30-month stay under the Hatch-Waxman framework.[6]

For atovaquone oral suspension, Paragraph IV risk is more likely to concern a later formulation or process patent than the active ingredient itself.

What manufacturing and intellectual-property barriers matter?

The main barriers are process and quality barriers rather than patent barriers.

Particle engineering

Micronization must produce a controlled distribution at commercial scale. The process must avoid heat buildup, contamination, uncontrolled agglomeration, and batch-to-batch changes in dissolution.

Suspension process order

The order of addition affects wetting and dispersion. A typical process may require separate preparation of the vehicle, hydration of the suspending agent, pre-wetting of atovaquone, controlled incorporation, homogenization, deaeration, and filling.

Microbial control

Aqueous multidose products require validated preservative efficacy, microbial limits, container-closure integrity, and in-use stability. Any change to benzyl alcohol concentration or preservative system requires a complete microbiological justification.

Packaging

A child-resistant bottle with a calibrated oral syringe can improve dose accuracy. Unit-dose sachets or stick packs could reduce microbial exposure and improve portability, but they may increase packaging costs and create fill-weight and dose-uniformity challenges.

How strong is the patent estate for atovaquone oral suspension?

The patent estate is weak as a barrier to conventional generic entry and potentially stronger for genuinely differentiated delivery systems.

Asset	Patent strength	Commercial value
Atovaquone molecule	Low because core protection expired	Low
Standard aqueous suspension	Low	Low to moderate
Novel taste-masked particles	Moderate if claims are narrow and reproducible	Moderate
Improved bioavailability platform	Moderate to high if clinically demonstrated	High
Preservative-free multidose system	Moderate	Moderate
Unit-dose packaging	Moderate	Moderate
Particle-engineering process	Moderate	Moderate
Pediatric dosing device	Moderate	Moderate

A new formulation patent should claim measurable technical advantages, such as improved redispersibility, reduced particle growth, enhanced dissolution, improved taste scores, reduced preservative exposure, or improved exposure under fed and fasted conditions. Broad claims covering “atovaquone in a suspension” are less likely to provide durable protection.

What commercial opportunities exist for improved atovaquone suspension?

Pediatric and swallowing-impaired patients

A more acceptable flavor, lower foaming, and calibrated oral syringe could improve adherence. Pediatric development would require careful dose-volume design and age-appropriate excipient justification.

Preservative-reduced or preservative-free products

A unit-dose presentation could address concerns about benzyl alcohol and reduce in-use contamination. The tradeoff is higher packaging and distribution cost.

Global malaria markets

A stable product that tolerates temperature excursions, has clear dosing instructions, and is available in smaller pack sizes could support public-sector and international procurement. Cost of goods remains decisive.

Improved food-independence

A formulation that reduces the food effect would have high clinical and commercial value, but it would require substantial pharmaceutical development and likely comparative pharmacokinetic evidence. A simple excipient change is unlikely to eliminate the underlying absorption limitations.

Oral syringe and adherence platform

A product bundled with a low-dead-space oral syringe, bottle adapter, and dose markings could differentiate the product without changing the drug substance. Device integration may create separate regulatory and intellectual-property opportunities.

Contract manufacturing and licensing

Licensing opportunities are more likely to involve:

• A proprietary micronized atovaquone supply process
• A taste-masked particle platform
• A preservative-free unit-dose suspension
• A pediatric delivery system
• Regional rights for malaria or HIV procurement channels
• A private-label product supplied by a specialized oral-liquid manufacturer

How does atovaquone compare with alternative Pneumocystis prophylaxis products?

Product	Dosage form	Main commercial distinction
Atovaquone suspension	Oral liquid	Alternative for patients unable to use sulfonamides; taste and food effect are limitations
Trimethoprim-sulfamethoxazole	Tablets, liquid, injectable	Lower cost and strong efficacy; tolerability limits use in some patients
Dapsone	Oral solid	Lower formulation complexity; hemolysis and G6PD considerations
Aerosolized pentamidine	Inhaled	Device and administration burden
Primaquine plus clindamycin	Oral combination	Alternative regimen with safety and adherence considerations

Atovaquone’s commercial position depends on clinical substitution value. It can command a premium over low-cost generic prophylaxis when patients need an alternative, but it is vulnerable to price pressure where tolerability does not justify the premium.

What revenue exposure does atovaquone create for manufacturers?

Revenue exposure is generally modest compared with protected specialty drugs because the product is generic and mature. The opportunity is strongest for manufacturers with:

• Existing oral-liquid manufacturing capacity
• Established infectious-disease distribution
• Government or hospital contracts
• Reliable micronization and suspension-processing capabilities
• A differentiated package or excipient platform
• Low-cost access to atovaquone API

Profitability may be constrained by low market volume, specialized quality requirements, and competing generic prices. A formulation improvement is more commercially attractive when it enables premium pricing, procurement preference, or durable differentiation rather than merely duplicating the reference product.

Key Takeaways

• Atovaquone oral suspension is a mature, genericized product with expired core exclusivity.
• The reference product uses micronized atovaquone, poloxamer 188, xanthan gum, benzyl alcohol, saccharin sodium, flavor, and water-based excipients.
• The main technical challenges are low solubility, particle wetting, sedimentation, caking, taste, and food-dependent absorption.
• The strongest formulation opportunities involve taste masking, improved redispersibility, preservative reduction, unit-dose packaging, pediatric dosing, and improved bioavailability.
• Patent value is more likely to arise from process, particle-engineering, device, or presentation claims than from the active ingredient.
• Biosimilar risk does not apply. Competition occurs through ANDA-based generic entry.
• Paragraph IV risk is limited for expired core patents but can arise from later formulation or process patents.
• Commercial success depends on supply reliability, cost of goods, procurement access, and measurable formulation differentiation.

FAQs

Can atovaquone oral suspension be reformulated without changing the approved indication?

Yes. A generic formulation can use different inactive ingredients if it satisfies FDA requirements for pharmaceutical equivalence, bioequivalence, safety, stability, and quality. Major formulation changes may require additional comparative studies.

Is benzyl alcohol essential in atovaquone suspension?

No. Benzyl alcohol is part of the reference formulation’s preservative system, but alternative preservative systems or unit-dose packaging may be possible. Each approach requires microbiological, stability, and regulatory support.

What is the most valuable excipient change for atovaquone suspension?

Taste masking has the clearest commercial value because poor palatability can impair adherence. A successful change must preserve dissolution, exposure, physical stability, and dose uniformity.

Can a new atovaquone suspension obtain new patent protection?

Yes, if it contains a novel and non-obvious formulation, particle architecture, manufacturing process, delivery device, or packaging system. Patent value depends on claim scope, enforceability, and demonstrated technical performance.

Does atovaquone suspension require administration with food?

The product label recommends administration with food because food increases atovaquone exposure.[1] A new formulation designed to reduce food dependence would require comparative pharmacokinetic evidence and could support meaningful commercial differentiation.

References

1. U.S. Food and Drug Administration. (2023). Mepron (atovaquone) oral suspension prescribing information.
2. National Library of Medicine. (n.d.). DailyMed: Atovaquone oral suspension, inactive ingredients and labeling.
3. U.S. Food and Drug Administration. (2019). Atovaquone oral suspension product quality and bioequivalence information.
4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book.
5. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: Mepron application and approval history.
6. U.S. Congress. (1984). Drug Price Competition and Patent Term Restoration Act, 21 U.S.C. § 355.