List of Excipients in Branded Drug ALLEGRA-D 24 HOUR

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
STAT RX USA LLC	ALLEGRA-D 24 HOUR	fexofenadine hydrochloride and pseudoephedrine hydrochloride	16590-852	ACETONE
STAT RX USA LLC	ALLEGRA-D 24 HOUR	fexofenadine hydrochloride and pseudoephedrine hydrochloride	16590-852	ALUMINUM OXIDE
STAT RX USA LLC	ALLEGRA-D 24 HOUR	fexofenadine hydrochloride and pseudoephedrine hydrochloride	16590-852	CELLULOSE ACETATE
STAT RX USA LLC	ALLEGRA-D 24 HOUR	fexofenadine hydrochloride and pseudoephedrine hydrochloride	16590-852	CELLULOSE, MICROCRYSTALLINE
STAT RX USA LLC	ALLEGRA-D 24 HOUR	fexofenadine hydrochloride and pseudoephedrine hydrochloride	16590-852	COPOVIDONE

Last updated: August 2, 2026

Allegra-D 24 Hour combines fexofenadine hydrochloride 180 mg with pseudoephedrine hydrochloride 240 mg in a once-daily extended-release tablet. Its commercial value is driven less by active-ingredient exclusivity than by controlled release, tablet architecture, pseudoephedrine channel restrictions, brand recognition, and reliable manufacturing. The strongest excipient strategy is a robust matrix or multilayer system that releases pseudoephedrine over approximately 24 hours while preserving rapid fexofenadine availability and tablet integrity.

Allegra-D 24 Hour Excipient Strategy, Patent Position, and Commercial Opportunities

What is the formulation of Allegra-D 24 Hour?

Allegra-D 24 Hour is an oral extended-release combination product containing:

Component	Strength per tablet	Function
Fexofenadine hydrochloride	180 mg	Second-generation antihistamine
Pseudoephedrine hydrochloride	240 mg	Nasal decongestant
Dosage form	One extended-release tablet	24-hour administration

The product is marketed for relief of allergy symptoms and nasal congestion. The high pseudoephedrine load makes the dosage form and release-control system central to product performance. The tablet must deliver a decongestant dose over an extended period without excessive early release or dose dumping.

FDA labeling identifies inactive ingredients used to support tablet formation, coating, lubrication, controlled release, and physical stability. Exact excipient levels and manufacturing process parameters are generally not disclosed in public labeling and can differ among authorized or generic products.[1]

Which excipients are strategically important in Allegra-D 24 Hour?

The commercial formulation strategy should divide excipients into five functional groups.

Release-controlling polymers

The pseudoephedrine component requires a release-control mechanism. Suitable polymer families include:

• Hypromellose, including high-viscosity grades
• Ethylcellulose
• Methacrylate copolymers
• Polyvinyl acetate-based controlled-release systems
• Combination polymer matrices

A hydrophilic hypromellose matrix is commercially attractive because it is widely available, scalable, and compatible with direct compression or wet granulation. The principal risks are variability in gel-layer formation, sensitivity to compression force, and differences in dissolution behavior after storage.

A membrane-coated multiparticulate system can offer tighter release control but normally increases manufacturing complexity, coating cost, and process-validation requirements.

Bulking and compression excipients

Microcrystalline cellulose is a conventional choice for improving tablet compactability and controlling tablet porosity. It can support robust compression at a high total tablet weight.

Lactose, mannitol, dibasic calcium phosphate, and spray-dried carbohydrate systems are alternative fillers. Selection should account for:

• Blend uniformity
• Tablet hardness
• Friability
• Moisture sensitivity
• Compatibility with pseudoephedrine hydrochloride
• Release-rate impact

Because the active load is high, the formulation has limited room for excessive excipient volume. A high-density filler may reduce tablet size, while a porous filler may improve liquid penetration and accelerate release.

Disintegrants and release modifiers

Croscarmellose sodium and sodium starch glycolate can improve breakup of immediate-release portions. In a controlled-release product, their concentration must be tightly managed. Excess disintegrant can create channels through the polymer matrix and increase the initial pseudoephedrine release rate.

For a bilayer or compartmentalized design, disintegrants can be concentrated in the fexofenadine portion while being excluded or minimized in the pseudoephedrine extended-release portion.

Binders and granulation aids

Povidone and hypromellose can improve granule strength and reduce segregation. The binder level affects tablet porosity, dissolution, and mechanical durability. Overbinding can slow liquid penetration and reduce release consistency.

Dry granulation is attractive where moisture sensitivity or process simplicity is important. Wet granulation may improve uniformity but introduces additional drying and residual-moisture controls.

Lubricants and glidants

Magnesium stearate is commonly used to improve ejection and reduce tooling friction. Excessive lubrication can create hydrophobic surfaces, weaken tablets, and alter dissolution. Colloidal silicon dioxide can improve flow, especially where the formulation contains high-density active ingredients or a coated release-control fraction.

The lubricant-mixing endpoint is a critical process variable. Overmixing can produce dissolution drift between batches.

What excipient architecture is most suitable for a commercial substitute?

Three architectures are commercially relevant.

Architecture	Advantages	Main risks	Commercial assessment
Single hydrophilic matrix	Simple, low-cost, scalable	Greater sensitivity to compression and excipient grade	Strong first-line approach
Bilayer tablet	Separates fexofenadine and pseudoephedrine functions	More equipment and process controls	Strong differentiation opportunity
Coated multiparticulate or reservoir system	Tight release control and reduced dose-dumping risk	Higher cost and complex validation	Premium or high-performance option

A bilayer tablet may provide the clearest technical advantage. Fexofenadine can be formulated for rapid availability, while pseudoephedrine is placed in a dedicated controlled-release layer. This architecture reduces direct excipient conflict between the antihistamine and decongestant components.

A single-layer matrix remains the most practical generic strategy where development cost and manufacturing simplicity are priorities. The development target should be equivalent dissolution across multiple media and agitation conditions, not merely matching a single nominal dissolution profile.

What formulation patents protect Allegra-D 24 Hour?

The primary commercial protection for Allegra-D 24 Hour is unlikely to depend on a currently enforceable composition-of-matter patent covering fexofenadine or pseudoephedrine. Both active ingredients are long-established small molecules. Product-level protection, where relevant, would more likely involve:

• Extended-release dosage-form architecture
• Polymer combinations
• Release profiles
• Bilayer tablet construction
• Manufacturing methods
• Stability improvements
• Combination therapy claims
• Method-of-use claims

Allegra-D 24 Hour is an over-the-counter product. FDA’s Orange Book primarily covers approved prescription drug products and does not provide the same patent-listing framework for ordinary OTC products marketed under an OTC monograph. As a result, a conventional Orange Book Paragraph IV pathway is not the central entry mechanism for this product.[2]

A developer should evaluate issued and expired U.S. patents covering fexofenadine-pseudoephedrine combinations, controlled-release pseudoephedrine systems, and the specific brand or authorized-generic product history. The relevant legal question is not whether an old patent once covered an extended-release combination, but whether any enforceable claim reads on the proposed formulation, process, or labeling at launch.

When does Allegra-D 24 Hour lose exclusivity?

Allegra-D 24 Hour does not have a conventional new-drug exclusivity profile comparable to a recently approved prescription product. Fexofenadine and pseudoephedrine are established active ingredients, and the product is sold through the OTC market.

Commercial exclusivity therefore depends on:

1. Brand equity and consumer recognition.
2. Retail placement.
3. Pharmacy-counter availability of pseudoephedrine.
4. Manufacturing consistency.
5. State and federal pseudoephedrine sales controls.
6. Any surviving formulation or process patents.
7. The ability to satisfy FDA OTC or abbreviated approval requirements.

Pseudoephedrine products are subject to federal sales controls under the Combat Methamphetamine Epidemic Act, including identification, logbook, purchase limits, and retail storage requirements.[3] These requirements create a barrier to broad convenience-store distribution and favor pharmacies and retailers with compliant inventory systems.

What FDA regulatory pathway applies to generic Allegra-D 24 Hour?

The regulatory pathway depends on the proposed product and its labeling.

OTC monograph pathway

A product using active ingredients, indications, dosage, and labeling consistent with the applicable OTC framework may be marketed under the monograph system, subject to current FDA requirements. The product must also comply with manufacturing, quality, labeling, and facility obligations.

Abbreviated new drug application

A manufacturer seeking approval as a generic of a listed prescription or approved reference product may use an ANDA where the regulatory framework supports that route. Bioequivalence, dissolution, labeling, and product-quality requirements would apply.

New drug application

A product with a materially different formulation, indication, delivery system, or regulatory position may require an NDA or other FDA submission.

For an extended-release combination, the critical development package includes pharmacokinetic comparability, in vitro release testing, stability, dose-dumping assessment, and evaluation under fed and fasted conditions where applicable. FDA’s extended-release product guidance treats formulation performance and in vitro-in vivo relationships as important elements of development and review.[4]

Which excipients create the greatest development risk?

Polymer-grade variability

Different viscosity grades of hypromellose or other release-control polymers can change pseudoephedrine release. Supplier qualification must include particle size, substitution type, viscosity, moisture, and lot-to-lot dissolution impact.

Alcohol-induced dose dumping

The formulation should be evaluated in hydroalcoholic media. A matrix that appears robust in standard aqueous dissolution may release pseudoephedrine too quickly when exposed to ethanol.

Food effects

High-fat meals can alter gastrointestinal transit and drug release. The formulation must be tested under relevant fed conditions to identify excessive exposure or early release.

Tablet splitting or crushing

Extended-release products should be designed and labeled to discourage manipulation. A formulation that releases a large portion of pseudoephedrine after crushing may create safety and regulatory concerns.

Moisture and coating stability

Moisture uptake can change matrix hydration, tablet hardness, and release rate. Packaging may require high-barrier bottles, desiccants, or protective blister systems.

Chemical compatibility

Fexofenadine hydrochloride and pseudoephedrine hydrochloride must remain chemically and physically stable in the selected matrix. Compatibility screening should cover polymer interaction, residual moisture, lubricant exposure, and accelerated storage.

What commercial opportunities exist for excipient innovation?

Smaller tablets

A high-density, high-load matrix could reduce tablet size and improve swallowing. This is commercially relevant because once-daily decongestant tablets can be large.

Improved release robustness

A bilayer or coated multiparticulate system could reduce variability caused by compression force, food effects, or polymer-grade changes.

Abuse-resistant design

Pseudoephedrine is not an opioid, but its diversion history creates a commercial rationale for formulations that are harder to extract, crush, or convert into illicit manufacturing inputs. Abuse-deterrent claims would require careful regulatory and evidentiary support.

Lower-cost generic supply

A formulation using broadly available excipients, direct compression, and standard coating equipment could compete on manufacturing cost. The principal opportunity is operational rather than patent-driven.

Alternative dosage forms

Potential extensions include:

• Smaller tablets
• Pharmacy-dispensed unit-dose packaging
• Pediatric or lower-strength products, subject to regulatory approval
• Orally disintegrating antihistamine-plus-decongestant products
• Combination products with modified antihistamine release

Each alternative must address pseudoephedrine’s high dose, taste, regulatory controls, and the need to preserve extended-release performance.

How does Allegra-D 24 Hour compare with competing allergy products?

Product category	Antihistamine	Decongestant	24-hour format	Main competitive issue
Allegra-D 24 Hour	Fexofenadine	Pseudoephedrine	Yes	Strong brand and established combination
Claritin-D 24 Hour	Loratadine	Pseudoephedrine	Yes	Direct antihistamine combination competitor
Zyrtec-D	Cetirizine	Pseudoephedrine	Extended-release	Sedation perception and brand competition
Antihistamine alone	Various	None	Often yes	Avoids pseudoephedrine restrictions
Intranasal decongestant or steroid	Various	Local or none	Variable	Different delivery route and symptom profile

The main technical differentiator is not the antihistamine molecule alone. It is the integration of a 24-hour pseudoephedrine release system with a tolerable tablet size, stable dissolution profile, and acceptable pharmacy-channel economics.

What generic launch risks exist?

Generic entry risks are primarily technical and commercial:

• Failure to match extended-release pharmacokinetics
• Excessive initial pseudoephedrine release
• Food-effect differences
• Dissolution divergence after storage
• Large or difficult-to-swallow tablets
• Retailer restrictions on pseudoephedrine inventory
• Limited shelf space behind the pharmacy counter
• Brand loyalty among seasonal allergy consumers
• Lower margins caused by controlled distribution and compliance costs

A successful entrant should prioritize bioequivalence and manufacturing reproducibility before adding novel excipients. Novel excipients may increase regulatory burden and create supplier dependency without delivering a commercially meaningful benefit.

What is the revenue exposure and market opportunity?

The addressable market includes consumers seeking simultaneous relief from allergic symptoms and nasal congestion. Revenue potential is strongest during seasonal allergy periods and in pharmacy-led channels.

The product’s economics are shaped by:

• OTC price premiums for branded combination products
• Seasonal demand
• Retailer and pharmacy placement
• Pseudoephedrine purchase controls
• Generic price erosion
• Manufacturing yield
• Packaging and compliance costs
• Availability of competing antihistamine-only products

A branded reformulation could support premium pricing only if it offers a visible consumer benefit, such as smaller size, improved tolerability, longer shelf life, or more reliable all-day congestion control. An undifferentiated generic matrix would compete mainly through supply reliability and cost.

What patent litigation and Paragraph IV risks affect Allegra-D 24 Hour?

No conventional Paragraph IV litigation analysis should be assumed solely because the product has a brand name. Paragraph IV litigation is tied to patents listed for an applicable reference drug in the Orange Book. An OTC combination product may instead face patent disputes involving formulation, process, trade dress, labeling, or proprietary technology.

A launch assessment should examine:

• U.S. patents assigned to the brand owner and formulation developers
• Patent family status in the United States, Canada, Europe, and other major markets
• Continuations and divisionals
• Terminal disclaimers
• Maintenance-fee status
• Patent expiration and abandonment records
• FDA product approvals and OTC monograph status
• Litigation involving extended-release pseudoephedrine products

The practical freedom-to-operate risk is likely to be concentrated in claim scope around controlled-release architecture rather than the active ingredients.

What licensing opportunities exist?

Licensing opportunities are most likely in the following areas:

• High-load extended-release matrix technology
• Bilayer tablet manufacturing
• Alcohol-resistant release systems
• Coated multiparticulate platforms
• High-speed compression and coating processes
• Packaging and pharmacy-compliance systems
• Regional rights for OTC allergy products

A licensee should prefer technology with demonstrated performance in high-dose, water-soluble actives. Generic controlled-release platforms may perform well with one drug but fail when transferred to pseudoephedrine because of rapid aqueous solubility and high dose loading.

Key Takeaways

• Allegra-D 24 Hour contains fexofenadine hydrochloride 180 mg and pseudoephedrine hydrochloride 240 mg.
• The key formulation challenge is 24-hour control of a high, water-soluble pseudoephedrine dose.
• Hypromellose matrices offer the best balance of cost, availability, and manufacturing scalability.
• Bilayer and coated multiparticulate systems provide stronger technical differentiation but raise cost and validation requirements.
• The product’s commercial exclusivity is driven primarily by brand, channel access, formulation know-how, and pseudoephedrine controls.
• Orange Book Paragraph IV litigation is not the default framework for an OTC Allegra-D product.
• The most attractive commercial opportunities are smaller tablets, improved release robustness, compliant pharmacy distribution, and lower-cost generic production.
• The main freedom-to-operate risk lies in extended-release formulation and manufacturing claims.

Frequently Asked Questions

Can Allegra-D 24 Hour be reformulated with a different release polymer?

Yes, provided the reformulated product satisfies applicable FDA requirements for quality, dissolution, pharmacokinetics, labeling, and stability. Polymer substitution can materially change release behavior and requires comparative development work.

Is pseudoephedrine the main excipient-development constraint?

No. Pseudoephedrine is an active ingredient, not an excipient. Its high dose and high aqueous solubility create the principal formulation constraint because the excipient system must control its release over 24 hours.

Does Allegra-D 24 Hour have biologic or biosimilar competition?

No. Allegra-D 24 Hour contains small-molecule active ingredients. Biosimilar pathways do not apply. Competition comes from OTC combinations, generic extended-release products, antihistamine-only products, and alternative nasal therapies.

Can a generic manufacturer use the same excipients as the branded product?

A generic manufacturer can generally use the same excipient classes, subject to FDA requirements and product performance. Matching the exact qualitative and quantitative formula is not always required, but the final product must meet applicable safety, quality, bioequivalence, and release specifications.

Which geographic markets offer the strongest licensing potential?

The United States offers the largest commercial opportunity but has strict pseudoephedrine controls. Canada, Europe, and Asia-Pacific markets may offer licensing opportunities, but product availability, decongestant restrictions, OTC classification, and formulation requirements differ by jurisdiction.

References

1. DailyMed. (n.d.). Allegra-D 24 Hour: Fexofenadine hydrochloride and pseudoephedrine hydrochloride extended-release tablet labeling. U.S. National Library of Medicine.
2. U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Drug Enforcement Administration. (n.d.). Retail sales of scheduled listed chemical products and pseudoephedrine requirements.
4. U.S. Food and Drug Administration. (2001). Guidance for industry: Extended release solid oral dosage forms: Development, evaluation, and application of in vitro/in vivo correlations.