List of Excipients in Branded Drug ERY-PED

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Azurity Pharmaceuticals Inc (formerly Arbor Pharmaceuticals)	ERY-PED	erythromycin ethylsuccinate	24338-132	CARAMEL
Azurity Pharmaceuticals Inc (formerly Arbor Pharmaceuticals)	ERY-PED	erythromycin ethylsuccinate	24338-132	POLYSORBATE 80
Azurity Pharmaceuticals Inc (formerly Arbor Pharmaceuticals)	ERY-PED	erythromycin ethylsuccinate	24338-132	SODIUM CITRATE
Azurity Pharmaceuticals Inc (formerly Arbor Pharmaceuticals)	ERY-PED	erythromycin ethylsuccinate	24338-132	SUCROSE

ERY-PED Excipient Strategy and Commercial Opportunities

Last updated: August 24, 2026

ERY-PED is an oral liquid formulation of erythromycin ethylsuccinate intended primarily for pediatric use. Its commercial value is driven less by active-ingredient exclusivity than by formulation performance: taste, dose accuracy, reconstitution stability, storage requirements, preservative system, and access to pediatric-friendly dosage forms. The strongest opportunities are sugar-free liquids, ready-to-use suspensions, improved taste systems, and reliable supply for outpatient and institutional markets.

What is ERY-PED and how is it formulated?

ERY-PED contains erythromycin ethylsuccinate, an orally administered erythromycin prodrug. The product is supplied as granules for oral suspension that are reconstituted with water before dispensing. Commercial strengths have included 200 mg/5 mL and 400 mg/5 mL presentations, although marketed availability can vary by manufacturer and time period.[1]

Erythromycin ethylsuccinate is used because it is more suitable for oral administration than erythromycin base in certain liquid formulations. The formulation must address several technical problems:

• Erythromycin compounds have an intensely bitter taste.
• The active pharmaceutical ingredient has limited aqueous solubility.
• Pediatric suspensions require rapid redispersion after settling.
• The product must remain chemically and microbiologically stable during its in-use period.
• Dosing errors are more likely when concentrations, measuring devices, or reconstitution instructions are unclear.

The core excipient platform generally includes a sweetener, buffer or pH-adjusting system, suspending aid, preservative, flavoring system, and processing excipients such as colloidal silicon dioxide. The exact composition depends on the marketed product and manufacturer’s approved labeling.

What excipients are used in erythromycin ethylsuccinate suspensions?

Typical excipient functions are summarized below.

Excipient category	Primary function	Commercial relevance
Sucrose or alternative sweetener	Masks erythromycin bitterness and improves mouthfeel	Affects pediatric acceptance, diabetic suitability, and tooth-decay concerns
Sodium citrate and citric acid	Controls pH and supports chemical stability	Influences erythromycin degradation and flavor profile
Colloidal silicon dioxide	Improves powder flow and suspension behavior	Supports manufacturing consistency and redispersion
Sodium benzoate or another preservative	Controls microbial growth after reconstitution	Important for multi-dose packaging and in-use shelf life
Flavors	Reduces bitterness and medicinal aftertaste	Affects adherence and repeat dispensing
Colorants	Supports product identification and consumer acceptance	Can create allergy, regulatory, and market-positioning constraints
Suspending polymers	Maintains uniformity and slows sedimentation	Determines dose homogeneity and dosing accuracy

The product’s excipient system must be assessed as a complete formulation. A sweetener change can alter viscosity, water activity, preservative efficacy, taste, and dissolution. A buffer change can affect both erythromycin stability and preservative performance.

What excipient strategy best improves ERY-PED?

The most commercially defensible strategy is a differentiated pediatric suspension platform rather than a simple copy of an existing formulation.

Taste masking is the primary formulation opportunity

Erythromycin is difficult to mask because bitterness can persist after swallowing. A successful taste strategy should combine:

1. A high-intensity sweetener or reduced-sugar base.
2. Fruit flavor selected for aftertaste control rather than initial aroma.
3. A viscosity profile that limits rapid contact with taste receptors.
4. Particle-size control or coating that reduces immediate dissolution in the mouth.
5. A pH range that balances taste, stability, and preservative activity.

Flavor-only reformulation is unlikely to create durable differentiation. The stronger approach is a multi-component system supported by sensory data, dissolution testing, and stability studies.

Potential flavor systems include cherry, grape, berry, and mixed fruit profiles. Grape and cherry are established pediatric liquid profiles, but a product owner should select the flavor based on comparative sensory testing in the target age group rather than adult preference data.

Sugar-free and low-sugar formulations address a clear market need

A sucrose-based suspension may be acceptable for many pediatric patients, but sugar-free products can target children with diabetes, repeated antibiotic exposure, dental-risk concerns, or caregiver preference for reduced sugar.

Candidate sweetener systems include:

• Sucralose
• Acesulfame potassium
• Saccharin sodium
• Sorbitol
• Xylitol
• Maltitol or other polyols

Each option has tradeoffs. Polyols can cause gastrointestinal effects at higher exposure levels. High-intensity sweeteners may leave a lingering aftertaste. Some systems can alter viscosity and preservative efficacy. A sugar-free formulation also requires careful evaluation of water activity and microbial control.

A reduced-sugar product may be easier to commercialize than a fully sugar-free product if the existing formulation already relies on sucrose for taste and bulk. A fully sugar-free product, however, offers clearer product differentiation.

Ready-to-use suspension could command a commercial premium

Granules for reconstitution reduce shipping weight and can improve long-term stability, but they create pharmacy and caregiver friction. Reconstitution errors can produce incorrect concentration, incomplete dosing, or shortened shelf life.

A ready-to-use suspension could compete on:

• No pharmacy reconstitution
• Lower caregiver error
• Faster dispensing
• Improved adherence to dosing instructions
• Potential compatibility with oral syringes
• Better suitability for emergency departments and urgent-care clinics

The main technical barriers are chemical stability, preservative performance, viscosity control, and shipping durability. A ready-to-use product may require a more advanced suspension system, oxygen-control strategy, light protection, or single-dose packaging.

Unit-dose and stick-pack presentations can reduce dosing errors

Pediatric antibiotic dosing is often weight-based. A unit-dose approach could package a measured volume corresponding to a common dose range or provide a concentrated formulation for use with an oral syringe.

Possible formats include:

• Unit-dose oral syringes
• Sachets for pharmacy reconstitution
• Small-volume bottles with calibrated syringes
• Dual-chamber bottles
• Powder-filled bottles with an integrated water mark
• Single-use cups for institutional dispensing

These features may support device, packaging, or combination-product protection even where the active ingredient has no meaningful composition-of-matter exclusivity.

What regulatory pathway applies to an improved ERY-PED formulation?

A conventional generic suspension would normally be pursued through an abbreviated new drug application if a suitable reference product and bioequivalence pathway are available. A materially different formulation may require a 505(b)(2) application, particularly when the sponsor relies on published literature or an approved reference product while introducing a new formulation, dosage form, concentration, or delivery system.[2]

ANDA opportunities

An ANDA strategy is most suitable for a formulation that matches the reference product in:

• Active ingredient
• Strength
• Dosage form
• Route of administration
• Labeling, subject to permitted differences
• Pharmaceutical equivalence
• Bioequivalence

Excipient differences may be acceptable, but they cannot compromise bioequivalence, stability, safety, or labeling requirements. Taste improvements alone do not automatically create a new regulatory pathway.

505(b)(2) opportunities

A 505(b)(2) approach may be more practical for:

• Ready-to-use suspension
• New concentration
• New container-closure system
• Sugar-free formulation with clinically relevant differentiation
• Extended in-use stability
• Novel taste-masking technology
• Unit-dose or device-integrated presentation

The sponsor would need to establish the clinical and pharmaceutical basis for the differences from the reference product. The commercial benefit is potentially greater, but development cost, regulatory review, and patent exposure can also increase.

What FDA quality issues are most important?

FDA review is likely to focus on suspension uniformity, assay, impurities, reconstitution, microbial limits, preservative effectiveness, extractables and leachables, container-closure integrity, and in-use stability.[3]

For a pediatric suspension, the development package should include:

• Shake-time and redispersion testing
• Dose uniformity across the bottle
• Pourability and syringe withdrawal studies
• Reconstitution volume tolerance
• Stability at refrigerated and room-temperature conditions
• Microbial challenge testing
• Taste and mouthfeel assessment
• Compatibility with common oral syringes
• Transport and freeze-thaw evaluation

What patents protect ERY-PED and its formulation?

Erythromycin and erythromycin ethylsuccinate are old active ingredients. The principal commercial risk is therefore unlikely to come from basic active-ingredient patents. It is more likely to involve formulation, manufacturing, packaging, delivery-device, or method-of-use rights.

A product-specific patent assessment should examine:

IP category	Potential scope	Commercial impact
Taste-masking composition	Coated particles, flavor systems, polymer matrices	May block a differentiated pediatric product
Suspension formulation	pH, viscosity, preservative, particle-size ranges	Can affect ANDA or 505(b)(2) design-around strategy
Ready-to-use formulation	Liquid stability and packaging	May support market exclusivity if technically narrow
Manufacturing process	Granulation, drying, milling, blending	Can create manufacturing barriers
Container-closure system	Integrated syringe, unit-dose package, dual chamber	Can support product differentiation
Method of use	Pediatric dosing or administration method	Usually narrower commercial value for an antibiotic
Trade secrets	Flavor ratios, process parameters, sensory optimization	Can protect know-how without public patent disclosure

The Orange Book should be checked for current patents and exclusivity listings associated with the specific reference product and active ingredient. Older erythromycin ethylsuccinate products may have no meaningful remaining patent protection, but the absence of an active-ingredient patent does not eliminate the risk of later formulation or device patents.[4]

When does ERY-PED lose exclusivity?

There is no single exclusivity date that applies to every ERY-PED presentation. Erythromycin ethylsuccinate is an established drug, and any remaining exclusivity would depend on the specific approved product, sponsor, formulation, and listing history.

The practical commercial conclusion is that ERY-PED should be evaluated as a mature generic or branded-generic opportunity. Market entry is more likely to depend on FDA approval, manufacturing reliability, product differentiation, and contracting than on protection from molecule-level generic competition.

Are Paragraph IV challenges relevant to ERY-PED?

A Paragraph IV certification is relevant only if an ANDA applicant identifies an unexpired Orange Book-listed patent for the reference product and certifies that the patent is invalid, unenforceable, or will not be infringed.[5]

For an old erythromycin ethylsuccinate suspension, the more likely scenarios are:

1. No listed patent remains, allowing a standard certification pathway.
2. A formulation or device patent remains, requiring a Paragraph IV analysis.
3. A new differentiated product receives later-listed patents that create a separate challenge window.
4. The applicant designs around the listed claims and files with a Paragraph III or non-infringement position where appropriate.

Any Paragraph IV strategy would require claim-by-claim analysis of particle size, excipient ranges, pH, concentration, reconstitution characteristics, packaging, and manufacturing steps. A broad challenge to the active ingredient would generally have limited value because the chemistry is longstanding.

Which companies could compete with an improved ERY-PED?

The competitive field includes manufacturers of erythromycin suspensions, broader pediatric antibiotic suppliers, and branded-generic companies with established pharmacy distribution.

Relevant competitor groups include:

• Suppliers of erythromycin ethylsuccinate oral suspensions
• Manufacturers of azithromycin and clarithromycin pediatric liquids
• Generic amoxicillin and amoxicillin-clavulanate suppliers
• Specialty pharmaceutical companies focused on pediatric dosage forms
• Contract manufacturers with oral-liquid capabilities
• Companies offering taste-masking or multiparticulate delivery technologies

Azithromycin is a major therapeutic competitor because it is dosed less frequently and is often perceived as easier to administer. Amoxicillin remains a stronger competitor in many pediatric indications because of cost, familiarity, and broad primary-care use. ERY-PED can compete where erythromycin’s spectrum, indication, allergy considerations, or clinical history supports prescribing.

What commercial opportunities exist for ERY-PED?

Pediatric specialty positioning

A differentiated product could target pediatricians, urgent-care providers, hospital discharge pharmacies, and specialty pharmacies. The value proposition should focus on reliable dosing and acceptability rather than broad antibiotic promotion.

Potential positioning includes:

• Sugar-free formulation
• Improved taste
• Ready-to-use packaging
• Oral-syringe compatibility
• Longer post-reconstitution shelf life
• Reduced reconstitution burden
• Consistent supply during generic disruptions

Institutional and hospital demand

Hospitals may value unit-dose presentations and products that reduce pharmacy preparation time. A ready-to-use product can support emergency departments, neonatal and pediatric wards, outpatient surgery centers, and discharge programs.

Institutional adoption depends on more than unit price. Important purchasing criteria include contract supply, back-order performance, barcode compatibility, packaging waste, storage requirements, and compatibility with medication-administration systems.

Geographic expansion

The active ingredient is established internationally, but pediatric formulations and regulatory requirements differ by jurisdiction. Opportunities may exist in markets where:

• Pediatric oral liquids are preferred over tablets.
• Erythromycin remains clinically relevant.
• Local supply is concentrated among few manufacturers.
• Sugar-free or alcohol-free formulations are underdeveloped.
• Pharmacies routinely compound or reconstitute products.

Any international strategy must address country-specific excipient restrictions, colorant rules, preservative limits, pediatric labeling, and stability requirements.

How strong is the patent estate for an ERY-PED reformulation?

The underlying molecule provides limited exclusivity leverage. A new product would need to build protection around formulation engineering and commercial execution.

Patent strength would be highest where claims cover:

• Narrow but defensible excipient ratios
• A defined taste-masking mechanism
• Improved chemical stability demonstrated across storage conditions
• A technically necessary particle-size or coating range
• A proprietary container-closure or dosing system
• A manufacturing process that is difficult to reproduce

Patent strength would be weaker where claims rely only on routine flavor substitution, common sweeteners, or broad functional language such as "improved taste" without a defined composition or measurable performance threshold.

Trade-secret protection may be valuable for flavor ratios, granulation conditions, coating parameters, and sensory-screening methods. The strongest commercial model may combine narrow formulation patents with confidential manufacturing know-how and a reliable pediatric supply chain.

Key Takeaways

• ERY-PED is an erythromycin ethylsuccinate oral suspension product designed for pediatric administration.
• Excipient strategy should prioritize bitterness control, suspension uniformity, preservative performance, and accurate dosing.
• Sugar-free, ready-to-use, and unit-dose presentations offer the clearest commercial differentiation.
• The active ingredient is mature, so formulation, packaging, device, manufacturing, and trade-secret protection are more relevant than molecule-level patents.
• An ANDA may fit a conventional equivalent product; a materially differentiated formulation may support a 505(b)(2) strategy.
• Azithromycin, clarithromycin, amoxicillin, and amoxicillin-clavulanate are important competitive products.
• Commercial success will depend on taste acceptance, supply reliability, pharmacy workflow, contracting, and regulatory execution.
• Patent value will be strongest when the formulation solves a measurable technical problem and is difficult to design around.

FAQs

Can ERY-PED be reformulated without sucrose?

Yes. A sugar-free ERY-PED formulation could use high-intensity sweeteners, polyols, or a combination system. The reformulation would require new evaluations of taste, viscosity, microbial control, preservative efficacy, stability, and dose uniformity.

Is erythromycin ethylsuccinate suitable for a ready-to-use liquid?

It can be considered for a ready-to-use suspension, but the formulation must establish adequate chemical and physical stability throughout the labeled shelf life and in-use period. The key development risks are degradation, sedimentation, redispersion, preservative performance, and taste.

Could an oral syringe be patented with an ERY-PED formulation?

Potentially. Patentable subject matter may include an integrated dosing system, dose-marking configuration, bottle-and-syringe combination, unit-dose package, or administration method. Patentability would depend on novelty, nonobviousness, claim scope, and prior art.

Does an improved ERY-PED formulation automatically receive new FDA exclusivity?

No. A formulation change does not automatically create regulatory exclusivity. Exclusivity depends on the approval pathway, the nature of the innovation, applicable statutory provisions, and FDA determinations.

What is the largest commercial risk for a new ERY-PED product?

The largest risk is weak differentiation against low-cost generic antibiotics and competing pediatric liquids. A new product must provide a measurable advantage in acceptability, dosing, supply reliability, or pharmacy efficiency to support premium pricing or preferred formulary placement.

References

1. U.S. Food and Drug Administration. (n.d.). DailyMed: Erythromycin ethylsuccinate oral suspension labeling. National Library of Medicine.

2. U.S. Food and Drug Administration. (2019). Applications covered by section 505(b)(2). FDA.

3. U.S. Food and Drug Administration. (1994). Approved drug products with therapeutic equivalence evaluations. FDA.

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

5. U.S. Food and Drug Administration. (2009). Submitting patent information and certifications in connection with an abbreviated new drug application. FDA.