List of Excipients in Branded Drug RYVENT

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Generic Drugs Containing RYVENT

Company	Ingredient	NDC	Excipient
Carwin Pharmaceutical Associates LLC	carbinoxamine maleate	15370-130	ANHYDROUS LACTOSE
Carwin Pharmaceutical Associates LLC	carbinoxamine maleate	15370-130	CELLULOSE, MICROCRYSTALLINE
Carwin Pharmaceutical Associates LLC	carbinoxamine maleate	15370-130	MAGNESIUM STEARATE
Carwin Pharmaceutical Associates LLC	carbinoxamine maleate	15370-130	SODIUM STARCH GLYCOLATE TYPE A POTATO

What are the Most Frequently-Used Excipients in RYVENT?

# Of NDCs	Excipient
1	ANHYDROUS LACTOSE
1	CELLULOSE, MICROCRYSTALLINE
1	MAGNESIUM STEARATE
1	SODIUM STARCH GLYCOLATE TYPE A POTATO

RYVENT Excipient Strategy and Commercial Opportunities for Carbinoxamine Maleate

Last updated: October 27, 2026

RYVENT is an immediate-release carbinoxamine maleate tablet used for allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, urticaria, and related allergic manifestations. Its commercial opportunity is primarily formulation-driven. Because carbinoxamine maleate is an established antihistamine, value is more likely to come from improved swallowability, excipient tolerability, pediatric delivery, supply reliability, and differentiated dosage forms than from new active-ingredient protection.

What is RYVENT and which excipients support its formulation?

RYVENT contains carbinoxamine maleate, a first-generation H1 antihistamine. The marketed product is an oral tablet. FDA labeling identifies inactive ingredients used to manufacture the tablet, including conventional tablet fillers, disintegrants, lubricants, and processing aids. The exact excipient composition should be confirmed against the current FDA labeling and DailyMed record before development or regulatory filing. [1,2]

Likely functional excipient architecture

Formulation function	Typical excipient role	Commercial relevance
Dilution and tablet mass	Lactose, microcrystalline cellulose, or another filler	Controls tablet size, hardness, and cost
Disintegration	Crospovidone, croscarmellose sodium, or sodium starch glycolate	Supports rapid breakup after swallowing
Granulation or binding	Povidone or a comparable binder	Improves compressibility and content uniformity
Flow improvement	Colloidal silicon dioxide	Supports high-speed tableting
Lubrication	Magnesium stearate or a lower-lubrication alternative	Reduces punch sticking and ejection force
Appearance	Film coat, colorant, or opacifier where used	Enables product identification and branding

The main formulation challenge is not chemical instability alone. It is balancing rapid disintegration with adequate tablet strength, acceptable mouthfeel, manufacturability, and low unit cost. Carbinoxamine maleate tablets can be positioned as a conventional immediate-release product, but a generic or reformulated competitor can seek differentiation through smaller tablets, lower friability, reduced chalkiness, or better swallowability.

What excipient strategy is most attractive for a RYVENT generic?

The lowest-risk strategy is an immediate-release tablet using established, compendial excipients with a formulation profile close to the reference product. An ANDA strategy would generally require pharmaceutical equivalence and bioequivalence to the reference product, with the regulatory pathway determined by FDA requirements and the product-specific guidance applicable at filing. [3]

Recommended base formulation strategy

A practical formulation platform would use:

1. A direct-compression or dry-granulation process.
2. Microcrystalline cellulose or another robust filler-binder system.
3. A high-efficiency disintegrant at a concentration sufficient to achieve rapid breakup without excessive friability.
4. Colloidal silicon dioxide for flow control.
5. A low concentration of magnesium stearate, with controlled blending time to avoid dissolution impairment.
6. A neutral, low-cost film coat or an uncoated tablet if the reference product and market positioning support that approach.

Direct compression offers the lowest process complexity and can reduce manufacturing cost. Dry granulation is more attractive when powder flow, segregation, or tablet-weight variability creates a risk. Wet granulation may improve compactability but introduces additional process steps and potential moisture exposure.

What excipient risks should a generic developer avoid?

A developer should avoid unnecessary changes that create bioequivalence or tolerability risk. Key risks include:

• Excessive lubricant levels that slow dissolution.
• High disintegrant levels that increase friability or produce an unpleasant mouthfeel.
• Lactose use in a product positioned for lactose-sensitive patients.
• Artificial colors that narrow the addressable patient population.
• Novel excipients that increase regulatory burden without a clear commercial benefit.
• Excessive tablet hardness that delays disintegration.
• Inadequate control of polymorphism, particle size, or blend uniformity of carbinoxamine maleate.

The most defensible initial product is a conventional, dye-controlled, rapidly disintegrating tablet with a familiar excipient profile and a reliable supply chain.

What formulation improvements could create commercial opportunities?

The strongest opportunities are dosage-form extensions rather than minor changes to the existing tablet.

Lactose-free and dye-free tablets

A lactose-free formulation could target patients who avoid lactose-containing medicines and simplify positioning against older antihistamine products. A dye-free product could appeal to caregivers and patients seeking fewer nonessential ingredients. These modifications may not create strong patent protection, but they can support retail differentiation and pharmacy substitution strategies.

Smaller or easier-to-swallow tablets

Carbinoxamine products are used by adults and pediatric patients, although dosing and age restrictions depend on the specific product and FDA labeling. A smaller tablet, improved tablet geometry, or scored presentation could address adherence and swallowing concerns. The opportunity is strongest where the formulation maintains the reference product's dissolution and exposure profile.

Orally disintegrating tablets

An orally disintegrating tablet could address patients who have difficulty swallowing conventional tablets. Development issues include:

• Taste masking, because carbinoxamine can produce an undesirable oral sensation.
• Mechanical strength during packaging and transport.
• Moisture protection.
• Rapid disintegration under USP testing conditions.
• Accurate dose delivery at a low tablet mass.

Useful taste-masking tools include polymeric coating, ion-exchange resins, lipid barriers, cyclodextrin complexes, and multiparticulate technologies. Each option increases development cost and may create a more defensible formulation patent position.

Chewable tablets

A chewable product may be more suitable for pediatric or adolescent use than a conventional tablet, but taste masking becomes central. Sweeteners, flavor systems, and mouthfeel modifiers can improve acceptability, but they also introduce stability, dental-health, and excipient-sensitivity considerations.

Oral liquid or extended-release liquid

Carbinoxamine has been commercialized in liquid and extended-release presentations by other manufacturers. A new oral liquid could compete through preservative selection, dosing-device accuracy, sugar-free composition, and reduced sedimentation. An extended-release liquid would have greater differentiation potential but would require more complex pharmacokinetic and product-performance development.

Potential excipient systems include:

• Suspending agents such as cellulose derivatives or xanthan gum.
• Buffer systems for pH control.
• Preservatives compatible with the active ingredient.
• Sweeteners and flavors for pediatric acceptance.
• Wetting agents to improve dispersion.
• Packaging systems that limit oxygen, light, or microbial ingress.

An oral liquid may qualify for a 505(b)(2) strategy if the proposed product differs materially from an approved reference product and relies partly on FDA findings for an existing product. The applicable pathway depends on the proposed dosage form, clinical data package, and reference product. [4]

What patents protect RYVENT and its excipient formulation?

The active ingredient, carbinoxamine, is an old antihistamine and is unlikely to provide meaningful new-molecule exclusivity for RYVENT. The principal IP issues are therefore likely to involve formulation, dosage form, manufacturing process, trademarks, and any product-specific patents listed by FDA.

Patent categories relevant to RYVENT

IP category	Relevance to RYVENT
Composition-of-matter patent	Limited commercial relevance because carbinoxamine is an established active ingredient
Immediate-release tablet patent	Potentially relevant if the sponsor claimed a specific excipient or manufacturing system
Extended-release formulation patent	More relevant to liquid or modified-release competitors
Taste-masking patent	Potentially relevant to ODT and chewable products
Method-of-use patent	May affect treatment claims, but older antihistamine indications are generally crowded
Manufacturing patent	May create barriers if it covers a specific granulation, coating, or release process
Trademark rights	Relevant to the RYVENT brand, but not to generic substitution

FDA's Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book, is the controlling public source for listed patents, exclusivity, and therapeutic-equivalence information for approved small-molecule products. [5] A development decision should distinguish between patents listed for the exact RYVENT product and patents associated with other carbinoxamine products.

When does RYVENT lose exclusivity and what is the generic entry risk?

RYVENT's generic-entry risk is structurally high because the active ingredient is established and the product is an immediate-release oral tablet. The primary commercial barriers are likely to be market size, manufacturing economics, product-specific regulatory requirements, and distribution access rather than active-ingredient patent protection.

Generic launch scenarios

Scenario	Product concept	Regulatory and commercial profile
Conventional ANDA	6 mg immediate-release tablet	Lowest development complexity and lowest differentiation
Improved tablet	Smaller, dye-free, lactose-free, or faster-disintegrating tablet	Moderate differentiation; limited IP strength
ODT	Taste-masked orally disintegrating tablet	Higher development cost; potential formulation IP
Chewable tablet	Flavored, pediatric-oriented product	Requires robust taste and texture performance
Oral solution	Immediate-release liquid	Useful for patients unable to swallow tablets
Extended-release liquid	Modified-release carbinoxamine product	Greater differentiation; higher clinical and CMC burden

A Paragraph IV certification would be relevant only if the reference product has eligible patents listed in the Orange Book. A generic applicant that challenges a listed patent may trigger patent litigation, a 30-month stay under applicable conditions, and potential first-filer advantages. The risk assessment must be product-specific because the existence, expiration, and enforceability of listed patents can change over time. [5,6]

What is the FDA regulatory status of RYVENT?

RYVENT is an FDA-approved prescription product containing carbinoxamine maleate. FDA labeling identifies the approved dosage form, strengths, indications, warnings, contraindications, and inactive ingredients. The label warns about sedation and other risks associated with first-generation antihistamines. Pediatric use requires particular attention because antihistamines can produce serious adverse effects in young children. [1]

A generic developer should assess:

• Reference-listed drug eligibility.
• Current Orange Book listing.
• Product-specific guidance, if available.
• Strength and dosage-form equivalence.
• Dissolution method and acceptance criteria.
• Inactive-ingredient suitability for the proposed route and population.
• Labeling differences, including warnings and age restrictions.
• Drug-supply and discontinuation status.

How strong is the RYVENT patent estate?

The likely patent estate is moderate to weak for a conventional immediate-release generic and potentially stronger for differentiated delivery systems. A standard tablet using common excipients is difficult to protect broadly because the formulation space is crowded and many excipients are well established.

Relative patent strength by opportunity

Opportunity	Patent strength potential	Main vulnerability
Conventional IR tablet	Low	Routine substitution of known excipients
Lactose-free tablet	Low to moderate	Design-around is straightforward
Dye-free tablet	Low	Easy to replicate
ODT with taste masking	Moderate to high	Formulation performance may be difficult to reproduce
Chewable tablet	Moderate	Taste and texture claims may be narrow
Extended-release liquid	High relative to tablet	Requires robust PK and release-control claims
Manufacturing process	Moderate	Process claims may be difficult to detect and enforce
Pediatric dosing device	Low to moderate	Device and packaging claims may provide limited protection

The strongest defensible IP would likely combine a specific carbinoxamine release profile with defined excipient ranges, particle-size parameters, dissolution criteria, and clinically relevant pharmacokinetic performance. Broad claims covering ordinary fillers and lubricants would face substantial validity and obviousness pressure.

Which companies could compete with RYVENT?

Competition can arise from three groups:

1. Generic manufacturers developing an equivalent carbinoxamine tablet.
2. Existing carbinoxamine suppliers selling oral liquids or extended-release products.
3. Manufacturers of alternative antihistamines, including cetirizine, levocetirizine, loratadine, desloratadine, and fexofenadine.

The competitive issue is therapeutic substitution. Second-generation antihistamines are commonly viewed as less sedating than first-generation products, which can constrain RYVENT's market expansion. A RYVENT competitor therefore needs a clear product proposition, such as pediatric acceptability, liquid dosing, tablet swallowability, or pharmacy-access pricing.

What licensing and partnering opportunities exist?

Licensing opportunities are more credible in formulation technology than in the carbinoxamine active ingredient. Potential partners include:

• Excipient companies with co-processed direct-compression systems.
• Taste-masking technology providers.
• Oral thin-film or ODT developers.
• Pediatric liquid-formulation specialists.
• Contract development and manufacturing organizations with antihistamine experience.
• Generic manufacturers seeking a low-cost ANDA platform.
• Regional distributors with established allergy and pediatric channels.

A licensing package would be more valuable if it included a demonstrated formulation, comparative dissolution data, accelerated stability, scalable manufacturing, and an enforceable patent position. A simple excipient substitution without measurable clinical or manufacturing benefit would have limited licensing value.

What manufacturing and IP barriers affect RYVENT opportunities?

Manufacturing barriers are manageable for a conventional tablet but increase sharply for ODT, chewable, and extended-release products.

Critical CMC controls include:

• Assay and content uniformity at low tablet strength.
• Powder segregation during blending.
• Lubrication time and dissolution impact.
• Moisture control.
• Tablet friability and packaging robustness.
• Stability of carbinoxamine maleate under heat and humidity.
• Microbial control for liquid products.
• Dose-delivery accuracy for pediatric liquids.
• Taste-masking durability throughout shelf life.

Geographic opportunities are strongest in the United States, where FDA approval and Orange Book status determine substitution. Other markets require separate assessments of national formularies, trademark rights, local patent registers, and regulatory pathways. A global strategy should avoid assuming that U.S. patent or exclusivity status controls Europe, Canada, Japan, or emerging markets.

Key Takeaways

• RYVENT is an established carbinoxamine maleate immediate-release tablet.
• The most practical generic strategy is a conventional tablet using established compendial excipients.
• Commercial differentiation is more promising through ODT, chewable, liquid, lactose-free, dye-free, or improved-swallowability products.
• Taste masking is the central technical issue for ODT and chewable formats.
• A conventional tablet is likely to have limited formulation-patent strength.
• Extended-release liquids and pediatric formulations offer stronger differentiation but require greater CMC and regulatory investment.
• Orange Book patents, exclusivity, and reference-product status must be verified for the specific RYVENT listing before a Paragraph IV or ANDA strategy is selected.
• Excipient suppliers and formulation technology companies are potential partners, while active-ingredient licensing is unlikely to be the principal value driver.

FAQs

Is RYVENT available as a generic?

Carbinoxamine maleate products may be available from multiple manufacturers, but generic availability depends on the specific strength, dosage form, FDA approval status, and current market supply. RYVENT-specific substitution should be confirmed through the current Orange Book and FDA-approved product listings.

Which excipient is most important in a RYVENT ODT?

The taste-masking system is likely to be the most commercially important excipient technology. The disintegrant, filler, and lubricant affect manufacturability, but patient acceptance will depend heavily on bitterness control and mouthfeel.

Can a lactose-free RYVENT tablet receive patent protection?

A lactose-free formulation can be patented only if it includes a novel and non-obvious formulation or process combination. Lactose removal alone is unlikely to provide broad, durable protection.

Is an extended-release carbinoxamine product a 505(b)(2) opportunity?

It may be, depending on the proposed formulation, reference product, clinical data, and FDA pathway determination. An extended-release product would require evidence supporting its release profile, exposure, safety, and labeling.

What is the highest-value commercial opportunity around RYVENT?

A differentiated pediatric or swallowing-friendly product is likely to have greater commercial value than another conventional immediate-release tablet, particularly if it combines acceptable taste, reliable dose delivery, low excipient burden, and defensible formulation IP.

References

1. U.S. Food and Drug Administration. (n.d.). RYVENT (carbinoxamine maleate) tablet prescribing information.
2. National Library of Medicine. (n.d.). DailyMed: RYVENT carbinoxamine maleate tablet.
3. U.S. Food and Drug Administration. (2024). Generic drug facts and ANDA requirements.
4. U.S. Food and Drug Administration. (2024). 505(b)(2) applications.
5. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
6. U.S. Code, 21 U.S.C. § 355(j). Abbreviated applications for new drugs.