List of Excipients in Branded Drug NAPROXEN SODIUM AND DIPHENHYDRAMINE HCL

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Generic Drugs Containing NAPROXEN SODIUM AND DIPHENHYDRAMINE HCL

Company	Ingredient	NDC	Excipient
TARGET CORPORATION	naproxen sodium and diphenhydramine hcl	11673-819	CELLULOSE, MICROCRYSTALLINE
TARGET CORPORATION	naproxen sodium and diphenhydramine hcl	11673-819	FD&C BLUE NO. 2--ALUMINUM LAKE
TARGET CORPORATION	naproxen sodium and diphenhydramine hcl	11673-819	HYPROMELLOSE 2910

What are the Most Frequently-Used Excipients in NAPROXEN SODIUM AND DIPHENHYDRAMINE HCL?

# Of NDCs	Excipient
1	CARNAUBA WAX
3	CELLULOSE, MICROCRYSTALLINE
1	FD&C BLUE NO. 2

Naproxen Sodium and Diphenhydramine HCl: Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: October 1, 2026

Naproxen sodium and diphenhydramine HCl is an OTC fixed-dose combination for nighttime pain relief. The reference commercial concept combines naproxen sodium, an NSAID analgesic, with diphenhydramine HCl, a sedating antihistamine used as a nighttime sleep aid. The principal commercial opportunity is not new chemical-entity exclusivity. It is differentiated delivery, tolerability, packaging, and compliant labeling.

A successful product must maintain rapid naproxen sodium release, consistent diphenhydramine dissolution, low moisture exposure, acceptable swallowability, and clear warnings about NSAID and sedative risks. The combination is best suited to immediate-release caplets, film-coated tablets, softgels, or other solid oral products that preserve the established OTC dosing framework.

What product contains naproxen sodium and diphenhydramine HCl?

The best-known commercial reference is Aleve PM, which contains naproxen sodium 220 mg and diphenhydramine HCl 25 mg per caplet. The product is marketed for temporary relief of minor aches and pains with nighttime sleep assistance. The label directs adults and children 12 years and older to take two caplets at bedtime, not exceeding two caplets in 24 hours unless directed by a physician. [1]

Attribute	Reference combination
Naproxen sodium	220 mg per caplet
Diphenhydramine HCl	25 mg per caplet
Dosage form	Immediate-release caplet
Primary use	Nighttime relief of minor aches and pains
Primary analgesic	NSAID
Sleep-aid component	First-generation antihistamine
Typical target user	Adults and adolescents 12 years and older
Key risks	Gastrointestinal bleeding, cardiovascular risk, sedation, impaired driving, anticholinergic effects

The fixed-dose combination is governed by the interaction of two OTC regulatory categories: internal analgesic products containing naproxen sodium and nighttime sleep-aid products containing diphenhydramine. FDA monographs establish permitted active ingredients, doses, labeling, and conditions for these categories. [2,3]

What excipients are used in naproxen sodium and diphenhydramine HCl tablets?

Reference labeling identifies a conventional immediate-release tablet system that may include microcrystalline cellulose, croscarmellose sodium, povidone, magnesium stearate, hypromellose, titanium dioxide, sodium lauryl sulfate, and colorants. Exact inactive ingredients vary by manufacturer and product presentation. [1]

Core excipient functions

Excipient category	Typical materials	Function
Diluent	Microcrystalline cellulose	Provides tablet mass and improves compressibility
Superdisintegrant	Croscarmellose sodium	Promotes rapid tablet breakup
Binder	Povidone	Improves granule or tablet strength
Lubricant	Magnesium stearate	Reduces ejection force and tooling adhesion
Film former	Hypromellose	Provides coating and mechanical protection
Surfactant	Sodium lauryl sulfate	Improves wetting of hydrophobic components
Opacifier	Titanium dioxide or equivalent	Controls appearance and light protection
Colorant	Approved FD&C color	Product identification and brand differentiation

The excipient platform is commercially mature. A generic manufacturer is unlikely to obtain meaningful differentiation from substituting one standard diluent for another. Greater value can come from improving dissolution robustness, tablet size, coating performance, moisture protection, or patient acceptability.

How should the excipient system be designed?

The formulation should prioritize immediate release and manufacturing robustness. Naproxen sodium is relatively high dose compared with diphenhydramine HCl, so the product is driven by tablet mass and compression behavior rather than by the antihistamine load.

Direct compression versus wet granulation

Direct compression can reduce processing steps and avoid water exposure. A formulation based on microcrystalline cellulose, mannitol, silicified microcrystalline cellulose, or a comparable compressible diluent may support a cost-efficient manufacturing process.

Wet granulation can improve content uniformity and mechanical strength but introduces moisture and drying variables. It may be less attractive where the active ingredients or selected excipients show moisture sensitivity. A dry-granulation or roller-compaction process can provide an intermediate approach.

The preferred development sequence is:

1. Screen direct compression blends.
2. Measure blend uniformity, flow, tensile strength, friability, and disintegration.
3. Compare dry granulation if direct compression produces capping, lamination, or segregation.
4. Use wet granulation only when it provides a clear quality or manufacturability advantage.

Disintegration and dissolution

Croscarmellose sodium, crospovidone, or sodium starch glycolate can support rapid disintegration. The selection should account for:

• Naproxen sodium dissolution across relevant pH conditions.
• Diphenhydramine HCl release from the same matrix.
• Compression force sensitivity.
• Tablet aging and humidity exposure.
• Potential over-lubrication from magnesium stearate.

A high lubricant concentration or excessive blending time can slow wetting and dissolution. Sodium lauryl sulfate may improve wetting, but its concentration should be controlled because it can affect tablet mouthfeel, gastrointestinal tolerance, and coating behavior.

Moisture and packaging

The product should be developed with moisture control in mind. Practical options include:

• High-barrier HDPE bottles with induction seals.
• Blister packaging using aluminum-based lidding and barrier-forming films.
• Desiccant canisters for bottle presentations.
• Low-water-content excipients.
• Film coatings that reduce surface moisture uptake.
• In-process humidity controls during blending and compression.

Packaging is a potentially stronger commercial differentiator than a minor excipient substitution. A manufacturer that demonstrates longer in-use stability, improved appearance retention, or better protection in humid climates may obtain a meaningful retail and international advantage.

What formulations are protected by the reference product?

The commercial concept is primarily an immediate-release oral combination. Potential formulation differentiation includes:

• Smaller tablets or caplets.
• Softgel capsules.
• Liquid-filled capsules.
• Taste-masked chewables.
• Orally disintegrating tablets.
• Low-sodium or sodium-free naproxen alternatives, subject to regulatory and clinical assessment.
• Unit-dose blister presentations.
• Dual-layer tablets separating the two actives before dissolution.
• Modified-release systems, although these would require substantially greater regulatory support.

A dual-layer tablet could separate naproxen sodium and diphenhydramine HCl during manufacture and storage. The commercial value would depend on demonstrated stability and dissolution benefits. It would also raise manufacturing complexity and may create a new product-specific regulatory package.

Modified release is less attractive for the standard nighttime use case. Naproxen is generally intended to provide analgesic activity over an extended period, while diphenhydramine is used for sleep initiation. A controlled-release design could alter the safety profile, duration of sedation, and labeling. It would likely require more than a simple monograph-based approach.

What is the FDA regulatory status of naproxen sodium and diphenhydramine HCl?

Both active ingredients have established OTC regulatory pathways, but a fixed-dose combination must satisfy the requirements applicable to each active ingredient and the combined labeling.

Naproxen sodium is recognized as an OTC internal analgesic active ingredient at the established 220 mg strength. Diphenhydramine HCl is recognized as an OTC nighttime sleep-aid active ingredient at the established 25 mg unit strength. [2,3]

The regulatory strategy depends on the product design:

Product approach	Likely regulatory burden
Monograph-compliant immediate-release caplet	Lowest
Same actives with minor excipient changes	Generally manageable if monograph conditions are met
New dosage form with unchanged indication	Higher CMC and labeling burden
Modified-release formulation	Potentially substantial
New age group or expanded indication	Clinical and regulatory risk
New combination ratio	May require additional FDA review
Novel delivery system	Likely outside a simple monograph pathway

FDA OTC monograph reform under the CARES Act has changed the procedural structure for nonprescription drugs. Manufacturers must evaluate the applicable OTC monograph order, labeling, quality requirements, and registration obligations rather than relying solely on historical monograph language. [4]

What is the Orange Book status of naproxen sodium and diphenhydramine HCl?

For a monograph-compliant OTC product, the Orange Book is not normally the primary source of market exclusivity. The relevant barriers are formulation know-how, trademarks, regulatory compliance, manufacturing capability, distribution, and brand recognition.

The active ingredients are old small molecules with expired foundational composition-of-matter patent positions. A new manufacturer could still pursue patents on:

• Specific excipient ratios.
• Coated or multilayer tablets.
• Moisture-protective systems.
• Softgel fill compositions.
• Taste-masking systems.
• Manufacturing processes.
• Stability-enhancing packaging.
• Specific dissolution profiles tied to a defined formulation.

A patent would need to satisfy novelty, nonobviousness, written-description, enablement, and claim-construction requirements. Broad claims covering ordinary combinations of naproxen sodium, diphenhydramine HCl, microcrystalline cellulose, croscarmellose sodium, and magnesium stearate would face substantial obviousness risk.

When does naproxen sodium and diphenhydramine HCl lose exclusivity?

The combination has no meaningful new-molecule exclusivity because both active ingredients are long-established OTC drugs. The relevant commercial question is whether a competitor can lawfully market a compliant product, not when a basic active-ingredient patent expires.

Exclusivity timeline

Exclusivity category	Position
Naproxen sodium composition-of-matter exclusivity	Expired
Diphenhydramine HCl composition-of-matter exclusivity	Expired
Standard OTC monograph pathway	Available, subject to compliance
Pediatric exclusivity	Not a central commercial barrier for the established product
Orphan exclusivity	Not applicable
Biosimilar exclusivity	Not applicable
Product-specific formulation patents	Possible, claim-dependent
Trademark exclusivity	Potentially important for branded products

There is no biosimilar risk because this is a synthetic small-molecule combination, not a biologic. The competitive threat comes from private-label, generic, store-brand, and alternative branded products.

Which companies are challenging the reference product?

The competitive field consists primarily of OTC manufacturers and private-label suppliers rather than companies pursuing biosimilar entry. Likely competitors include:

• Branded manufacturers selling naproxen-based nighttime products.
• Generic drug companies producing combination caplets.
• Retail pharmacy private-label suppliers.
• Contract manufacturers supplying national retailers.
• Products combining an NSAID or acetaminophen with diphenhydramine or another nighttime ingredient.

The most credible competitive advantage is usually retail execution, not patent exclusion. Shelf placement, retailer relationships, packaging economics, product availability, and promotional spending can materially affect market share.

What patent litigation affects naproxen sodium and diphenhydramine HCl?

No central biologic or small-molecule patent dispute controls this product category. Any litigation risk would more likely involve:

• A formulation patent on a branded combination.
• Trade dress or trademark claims.
• Labeling or advertising claims.
• Manufacturing-process patents.
• Alleged infringement involving a novel softgel or modified-release platform.

Paragraph IV litigation is less likely for a traditional monograph-compliant OTC product because entry does not depend on challenging a listed NDA patent in the same way as a conventional prescription generic. If a sponsor develops an NDA-based formulation, the applicable patent certification and litigation analysis would change.

How strong is the patent estate for this combination?

The baseline patent estate is weak for the active ingredients and conventional immediate-release tablet. The estate can become stronger if it is tied to a technically meaningful formulation result.

Patent target	Commercial strength
Basic naproxen sodium/diphenhydramine combination	Low
Conventional excipient substitution	Low
Defined low-moisture formulation with unexpected stability	Moderate
Novel multilayer tablet with demonstrated separation benefit	Moderate
Novel softgel or liquid-filled system	Moderate to potentially strong
Improved dissolution with reduced tablet mass	Moderate
Packaging-only claims	Narrow but commercially useful
Manufacturing process with measurable yield or quality advantage	Moderate

The strongest patent strategy would combine composition claims with process and packaging claims. Claims should be supported by comparative data showing a measurable advantage over ordinary immediate-release tablets.

What commercial opportunities exist for excipient suppliers?

Excipient suppliers can pursue value in four areas.

Low-moisture direct-compression platforms

A ready-to-use excipient blend that delivers high tabletability, rapid disintegration, and low humidity sensitivity could reduce development time for OTC manufacturers.

Taste and mouthfeel improvement

Diphenhydramine HCl is bitter, while naproxen sodium can produce an alkaline or saline taste. Chewable and orally disintegrating products therefore need taste-masking technology, such as polymeric coating, ion exchange, lipid barriers, or multiparticulate encapsulation.

Coating and appearance systems

A robust film-coating system can reduce chipping, improve color consistency, and support product identification. Color and coating choices must comply with FDA requirements and retailer-specific standards.

Sustainable excipient systems

Manufacturers may seek lower-solvent processes, lower coating weight, recyclable packaging, and excipients sourced from renewable materials. Sustainability claims would need to be supported by supply-chain and lifecycle data.

How does this combination compare with competing nighttime pain products?

Product concept	Analgesic	Nighttime ingredient	Main commercial advantage	Main risk
Naproxen sodium plus diphenhydramine	NSAID	Antihistamine	Long analgesic duration with sleep-aid positioning	NSAID warnings and next-day sedation
Acetaminophen plus diphenhydramine	Analgesic/antipyretic	Antihistamine	Broad consumer familiarity	Liver toxicity concerns with overdose
Ibuprofen plus diphenhydramine	NSAID	Antihistamine	Familiar NSAID brand category	Shorter dosing interval and NSAID risks
Naproxen sodium alone	NSAID	None	Longer-lasting pain relief	No sleep-aid benefit
Diphenhydramine alone	None	Antihistamine	Direct sleep-aid positioning	No analgesic activity

Naproxen sodium provides a differentiated duration profile relative to shorter-acting analgesics. The tradeoff is a more prominent NSAID safety profile, including gastrointestinal bleeding and cardiovascular warnings. Product claims and packaging must avoid encouraging repeated or prolonged use.

What generic launch scenarios exist?

The most likely launch scenarios are:

1. A private-label immediate-release caplet using a conventional excipient system.
2. A lower-cost generic with equivalent active strengths and simplified packaging.
3. A softgel positioned around swallowability and rapid onset.
4. A smaller or easier-to-swallow caplet using higher-density excipients.
5. A premium product using unit-dose blister packaging and enhanced moisture protection.
6. A retailer-exclusive product with differentiated branding rather than technical exclusivity.

The fastest route is a monograph-aligned immediate-release product. A novel dosage form can command higher margins but carries greater development, stability, scale-up, and regulatory risk.

What revenue exposure and market risks matter?

Revenue exposure is concentrated in OTC retail demand rather than prescription reimbursement. The major variables are:

• Seasonal pain and cold-related demand.
• Retailer shelf placement.
• Brand advertising.
• Private-label price competition.
• Consumer sensitivity to NSAID warnings.
• Supply continuity for active ingredients and critical excipients.
• Packaging cost and freight efficiency.
• Product recalls caused by contamination, mislabeling, or stability failures.

The combination also has a usage-risk issue. Consumers may take other diphenhydramine-containing products or additional NSAIDs at the same time. Clear Drug Facts labeling and package design are commercially important because poor comprehension can trigger regulatory action, recalls, or retailer delisting.

Key Takeaways

• Naproxen sodium 220 mg plus diphenhydramine HCl 25 mg is an established OTC nighttime pain-relief combination.
• The most practical dosage form is an immediate-release film-coated caplet.
• Conventional excipients include microcrystalline cellulose, croscarmellose sodium, povidone, magnesium stearate, hypromellose, surfactants, opacifiers, and colorants.
• The strongest formulation opportunities involve moisture protection, dissolution control, tablet-size reduction, taste masking, softgels, and unit-dose packaging.
• Foundational active-ingredient exclusivity has expired, and biosimilar risk is irrelevant.
• A monograph-compliant product generally faces limited Orange Book-driven entry barriers.
• Patent value depends on technically supported formulation, manufacturing, or packaging claims.
• Commercial competition is likely to come from private-label and generic OTC manufacturers.
• The principal safety risks are NSAID-related gastrointestinal and cardiovascular effects and diphenhydramine-related sedation and anticholinergic effects.

FAQs

Can naproxen sodium and diphenhydramine HCl be formulated as a chewable tablet?

Yes, but taste masking is a primary development issue. Polymer-coated particles, lipid barriers, ion-exchange systems, or multiparticulate technology may be required. The product must maintain rapid dissolution after masking.

Is a softgel commercially attractive for this combination?

A softgel could improve swallowability and create a premium product position. Its disadvantages include higher manufacturing cost, fill compatibility constraints, shell stability requirements, and potentially greater packaging sensitivity.

Can excipients reduce the gastrointestinal risk of naproxen sodium?

Excipients can improve dissolution control and tolerability characteristics but do not eliminate the intrinsic NSAID risks of naproxen. Any claim of reduced gastrointestinal injury would require substantial supporting evidence and careful regulatory review.

Would an orally disintegrating tablet improve market access?

It could benefit consumers who have difficulty swallowing tablets. The main technical barriers are the high naproxen sodium dose, bitter taste, tablet friability, moisture sensitivity, and the need to prevent premature dissolution in the mouth.

Is a new fixed-dose ratio likely to obtain patent protection?

A different ratio alone is unlikely to provide strong protection unless it produces an unexpected clinical, pharmacokinetic, stability, or tolerability result. A patent position is more credible when the ratio is part of a novel formulation supported by comparative data.

References

1. Bayer HealthCare LLC. (n.d.). Aleve PM: Drug facts. DailyMed, U.S. National Library of Medicine.

2. U.S. Food and Drug Administration. (2022). 21 CFR Part 343: Internal analgesic, antipyretic, and antirheumatic drug products for over-the-counter human use. Electronic Code of Federal Regulations.

3. U.S. Food and Drug Administration. (2022). 21 CFR Part 338: External analgesic drug products for over-the-counter human use. Electronic Code of Federal Regulations.

4. U.S. Food and Drug Administration. (2023). Over-the-counter monograph drugs. FDA.

5. U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations, 43rd edition. FDA.