List of Excipients in Branded Drug NAPROXEN SODIUM PM

Generic Drugs Containing NAPROXEN SODIUM PM

Company	Ingredient	NDC	Excipient
Safeway	diphenhydramine hydrochloride, naproxen sodium	21130-639	CELLULOSE, MICROCRYSTALLINE
Safeway	diphenhydramine hydrochloride, naproxen sodium	21130-639	CROSCARMELLOSE SODIUM
Safeway	diphenhydramine hydrochloride, naproxen sodium	21130-639	FD&C BLUE NO. 1 ALUMINUM LAKE
Safeway	diphenhydramine hydrochloride, naproxen sodium	21130-639	FD&C BLUE NO. 2 ALUMINUM LAKE

What are the Most Frequently-Used Excipients in NAPROXEN SODIUM PM?

# Of NDCs	Excipient
4	CARNAUBA WAX
9	CELLULOSE, MICROCRYSTALLINE
5	CROSCARMELLOSE SODIUM
2	FD&C BLUE NO. 1

Naproxen Sodium PM Excipient Strategy and Commercial Opportunities

Last updated: August 22, 2026

Naproxen sodium PM products combine an analgesic and anti-inflammatory ingredient with a nighttime sleep aid. The leading reference model is Aleve PM, which contains naproxen sodium 220 mg and diphenhydramine citrate 38 mg per caplet, equivalent to diphenhydramine hydrochloride 25 mg [1]. The strongest commercial opportunities are differentiated dosage forms, improved swallowability, lower sedation burden, targeted packaging, and private-label or regional OTC expansion rather than new chemical-entity exclusivity.

What is naproxen sodium PM?

Naproxen sodium PM is a combination OTC product intended for nighttime relief of minor aches and pains with occasional sleeplessness associated with those aches. Its two active ingredients have different formulation roles:

Component	Typical amount per unit	Function
Naproxen sodium	220 mg	NSAID analgesic and antipyretic
Diphenhydramine citrate	38 mg	Nighttime sleep aid, equivalent to diphenhydramine HCl 25 mg

Naproxen sodium is the sodium salt of naproxen. It is more water-soluble than naproxen free acid and is commonly used for faster dissolution in immediate-release solid oral products. Diphenhydramine citrate is a sedating antihistamine used in OTC sleep-aid products.

The combination creates a formulation and commercial constraint: the product must deliver adequate naproxen exposure while controlling diphenhydramine-related taste, friability, dissolution, sedation messaging, and tablet size.

What excipients are used in naproxen sodium PM products?

The exact excipient profile depends on the manufacturer and dosage form. A representative naproxen sodium PM caplet may include fillers, binders, disintegrants, lubricants, coating agents, colorants, and polishing materials. Public labeling for branded products identifies inactive ingredients, but does not always disclose the full manufacturing grade, particle-size distribution, process parameters, or supplier qualification data [1].

Typical excipient classes include:

Excipient function	Candidate materials	Formulation purpose
Diluent	Microcrystalline cellulose, lactose, starch, calcium phosphate	Controls tablet mass and compressibility
Binder	Povidone, pregelatinized starch, hydroxypropyl cellulose	Improves granule and tablet strength
Disintegrant	Croscarmellose sodium, sodium starch glycolate, crospovidone	Promotes rapid tablet breakup
Lubricant	Magnesium stearate, sodium stearyl fumarate	Reduces ejection force and tooling adhesion
Glidant	Colloidal silicon dioxide	Improves powder flow
Film former	Hypromellose, polyethylene glycol	Protects the tablet and improves appearance
Opacifier or colorant	Titanium dioxide, iron oxides, approved dyes	Product identification and light protection
Polishing agent	Carnauba wax or equivalent	Surface finish and handling

The most important excipient risks are naproxen sodium’s moisture sensitivity, the high drug load, potential interaction between alkaline sodium naproxen and formulation components, and the need to achieve rapid release from a relatively dense caplet.

Which excipient strategy best supports immediate-release naproxen sodium PM?

A direct-compression or dry-granulation platform is generally commercially attractive because it limits water exposure and reduces process complexity. Naproxen sodium can be incorporated into a high-load tablet with microcrystalline cellulose, a superdisintegrant, colloidal silicon dioxide, and a low-level lubricant.

A practical platform strategy is:

1. Use a low-moisture diluent system.
2. Select a superdisintegrant that maintains performance after compression.
3. Control lubricant concentration and blending time to avoid dissolution retardation.
4. Apply a thin protective film coating rather than a heavy functional barrier.
5. Package in high-barrier blister or bottle systems with desiccant capability where stability data justify it.

The key development target is not simply tablet hardness. It is the balance between mechanical durability, rapid disintegration, dissolution, content uniformity, and acceptable tablet size.

Direct compression versus dry granulation

Attribute	Direct compression	Dry granulation
Water exposure	Low	Low
Capital intensity	Lower	Higher
Blend uniformity risk	Higher for low-dose diphenhydramine component	Lower if granule segregation is controlled
Tablet density	Usually lower	Often higher
Scale-up	Straightforward with robust powder properties	More process steps but greater control
Commercial fit	Attractive for standard caplets	Useful where flow, segregation, or compressibility are limiting

Diphenhydramine citrate is present at a lower mass than naproxen sodium. Blend segregation can therefore affect content uniformity, particularly when the formulation includes multiple particle-size populations. A co-processing approach or controlled premix can reduce this risk.

What formulation patents could protect naproxen sodium PM products?

The active ingredients are old, and broad composition-of-matter protection is unavailable. Commercial protection would need to come from formulation, manufacturing, packaging, or brand rights.

Potentially protectable subject matter includes:

• A specific naproxen sodium and diphenhydramine ratio.
• A defined immediate-release dissolution profile.
• A multilayer or bilayer tablet separating the two actives.
• A taste-masked or orally disintegrating formulation.
• A low-moisture manufacturing process.
• A controlled-release naproxen component with immediate-release diphenhydramine.
• A unit-dose blister system that improves stability.
• A formulation with reduced tablet weight or improved swallowability.

Patentability depends on the claimed excipient levels, process conditions, performance data, and prior-art landscape. A generic combination using conventional excipients and ordinary immediate-release performance would face a weak patent position.

How strong is the patent estate for naproxen sodium PM?

The patent estate is likely weak for the conventional caplet category because:

• Naproxen sodium has been marketed for decades.
• Diphenhydramine sleep-aid products are well established.
• Standard tablet excipients are heavily represented in prior art.
• OTC monograph marketing reduces reliance on product-specific approval exclusivity.
• Product differentiation is more likely to depend on trademarks, shelf placement, manufacturing cost, and consumer recognition.

A stronger estate could arise from a technically differentiated formulation that shows a measurable advantage, such as improved stability under high humidity, a reduced-size caplet, better dissolution after long-term storage, or a distinct pharmacokinetic profile.

What is the FDA regulatory status of naproxen sodium PM?

Naproxen sodium 220 mg is regulated in the United States under the OTC monograph framework for internal analgesic, antipyretic, and antirheumatic products. The relevant framework is codified in 21 C.F.R. Part 343 [2]. Diphenhydramine is also an established OTC nighttime sleep-aid ingredient under the applicable FDA monograph provisions [3].

A compliant product generally requires:

• Permitted active ingredients and strengths.
• Required Drug Facts labeling.
• Applicable warnings for NSAID use.
• Required nighttime sleep-aid warnings.
• Manufacturing under current good manufacturing practice.
• Stability and quality documentation.
• Conformance with applicable excipient and packaging requirements.

The product must communicate important NSAID risks, including stomach bleeding, cardiovascular events, allergic reactions, and use limitations. Diphenhydramine labeling must address sedation and avoid-use warnings involving alcohol, sedatives, tranquilizers, and certain medical conditions.

What is the Orange Book status of naproxen sodium PM?

Naproxen sodium PM OTC products marketed under the FDA monograph pathway generally do not have the same Orange Book patent-listing structure as approved prescription products. The Orange Book primarily identifies approved drug products, therapeutic equivalence evaluations, and patent or exclusivity information associated with approved applications [4].

A manufacturer pursuing a monograph-compliant OTC product normally does not depend on:

• New drug application exclusivity.
• Paragraph IV certification.
• Orange Book-listed formulation patents.
• Abbreviated new drug application substitution mechanics.

If a product is marketed under an approved application rather than solely under the monograph, the regulatory and patent analysis can differ. The commercial opportunity should therefore be evaluated by product pathway, not by the brand name alone.

When does naproxen sodium PM lose exclusivity?

There is no single universal loss-of-exclusivity date for the active ingredient combination. The commercial barriers depend on separate rights:

Barrier	Typical relevance
Naproxen sodium active-ingredient patents	Generally expired
Diphenhydramine active-ingredient patents	Generally expired
Combination patents	May exist but are product-specific
Trademark rights	Continue while maintained and used
OTC monograph compliance	Applies to all compliant competitors
Trade dress	Protects appearance within legal limits
Manufacturing know-how	May remain confidential
Retail contracts	Commercial, not regulatory exclusivity

The reference product can therefore face private-label, store-brand, and branded competition without waiting for a conventional prescription patent cliff.

Are Paragraph IV challenges relevant to naproxen sodium PM?

Paragraph IV litigation is generally not the primary entry mechanism for a standard OTC monograph product. Paragraph IV certifications apply to abbreviated new drug applications referencing listed prescription or approved drug products with relevant Orange Book patents. A monograph-compliant OTC entrant usually reaches the market through compliance with the monograph and general FDA requirements rather than by challenging an Orange Book patent [2,4].

A Paragraph IV strategy could become relevant if a combination product is subject to an approved application with listed patents. That scenario must be analyzed separately from ordinary OTC monograph competition.

What formulation opportunities exist for naproxen sodium PM?

Smaller tablets and improved swallowability

The combination can create a relatively large unit dose. A smaller caplet could support premium positioning among older consumers and patients with dysphagia. Opportunities include:

• Higher-density excipient systems.
• Bilayer compression.
• Optimized particle-size distribution.
• Reduced coating weight.
• Mini-caplets taken as multiple units.
• Softgel or liquid-filled capsule formats.

A smaller unit must still meet dissolution, dose uniformity, hardness, friability, and stability requirements.

Fast-onset nighttime relief

A rapid-release design could target consumers seeking analgesic relief before sleep. The formulation should not imply a pharmacokinetic advantage without comparative data. A fast-disintegrating tablet, effervescent product, or liquid-filled capsule could differentiate the product through consumer experience.

Reduced-sedation positioning

Diphenhydramine is effective as a sedating antihistamine but can cause next-day drowsiness, anticholinergic effects, and impaired alertness. A commercial opportunity exists in a separate product concept combining naproxen sodium with a lower-sedation sleep-support ingredient, but that would require a distinct regulatory and clinical assessment. It would not be a straightforward generic equivalent of naproxen sodium PM.

Age-targeted and accessibility products

A coated tablet with improved swallowability, large-print packaging, unit-dose blistering, and clear contraindication communication could target older consumers. Any product marketed to older adults must handle the safety concerns associated with NSAIDs and sedating antihistamines carefully.

Packaging-led stability differentiation

High-barrier packaging can provide a defensible quality advantage where the product is sensitive to moisture or prolonged heat exposure. Options include:

• Cold-form aluminum blisters.
• High-barrier PVC or PVdC blister systems.
• HDPE bottles with induction seals.
• Desiccant canisters or packets.
• Unit-dose packaging that limits repeated humidity exposure.

Packaging claims require stability data and should not be treated as a substitute for formulation optimization.

Which companies are challenging the branded naproxen sodium PM market?

Competition is likely to come from four groups:

1. National OTC brands selling naproxen products.
2. Retailer private-label products.
3. Generic manufacturers supplying store brands.
4. Combination-product specialists and contract manufacturers.

The principal competitive advantages are cost, retailer access, manufacturing reliability, consumer trust, and packaging. Because active ingredients are inexpensive and widely available, the supplier with the lowest total delivered cost can compete effectively unless the brand has strong retail pull.

Private-label products may use the same active ingredients and similar excipient systems while reducing promotional and packaging costs. A differentiated entrant should therefore avoid relying solely on the phrase "naproxen sodium PM." It needs a clear point of difference, such as smaller size, better packaging, faster disintegration, or a lower-cost multipack.

What commercial opportunities exist for naproxen sodium PM?

Private-label and retailer licensing

The most immediate opportunity is retailer-exclusive or regional private-label supply. The product can be manufactured under contract with:

• Retailer-specific labeling.
• Multipack and club-store formats.
• Seasonal sleep and pain merchandising.
• Pharmacy-counter and e-commerce packaging.
• Dual-language labeling where commercially appropriate.

Geographic expansion

Naproxen and diphenhydramine are established ingredients in many markets, but combination products are subject to local rules on OTC status, maximum strengths, labeling, and permissible sleep-aid claims. Expansion opportunities are strongest where:

• Naproxen sodium is accepted for nonprescription use.
• Diphenhydramine is permitted in nighttime products.
• Local regulators accept the combination without a full new-drug development program.
• Retail pharmacy distribution is established.

The product should be assessed separately in the United States, Canada, the European Union, Latin America, and Asia-Pacific because NSAID and sedating-antihistamine controls vary substantially.

Premium dosage forms

A liquid-filled capsule, orally disintegrating tablet, or blister-packed mini-caplet could command a higher price than a standard caplet. Premium pricing must offset development, stability, packaging, and manufacturing costs.

Manufacturing and supply-chain optimization

The most practical margin improvements may come from:

• Reducing tablet weight.
• Increasing compression speed.
• Eliminating wet granulation.
• Consolidating excipient suppliers.
• Using common packaging components across SKUs.
• Improving line yield and reducing coating defects.
• Establishing dual-source API and excipient supply.

A dry process with robust blend uniformity can reduce both capital requirements and batch-cycle time.

What generic launch risks exist for naproxen sodium PM?

Generic and private-label entry risks are high for a conventional formulation. Key risks include:

Risk	Commercial impact
Low-cost private-label supply	Compresses retail price
Retailer substitution	Reduces branded shelf presence
Small formulation differences	Can affect dissolution or stability
Diphenhydramine supply constraints	Delays launch or increases cost
NSAID safety warnings	Limits promotional claims
Sedation concerns	Restricts target population
Packaging failures	Creates stability and recall exposure
Trademark similarity	Creates branding and litigation risk

The product also carries liability exposure because consumers may use it for repeated or chronic pain despite label limitations. Regulatory review should focus on dosing instructions, duplicate NSAID use, alcohol warnings, sedation, and contraindicated populations.

What patent litigation and settlement issues affect naproxen sodium PM?

For a standard OTC monograph product, litigation is more likely to involve trademarks, trade dress, advertising claims, supplier disputes, or formulation-specific patents than Paragraph IV settlements. A company developing a differentiated formulation should conduct a freedom-to-operate review covering:

• Combination patents.
• Drug-delivery patents.
• Softgel and capsule technologies.
• Taste-masking systems.
• Controlled-release naproxen systems.
• Packaging patents.
• Brand names and trade dress.
• Manufacturing process claims.

A settlement agreement could restrict launch timing or territory if a formulation patent is asserted. No broad settlement assumption should be built into valuation without identifying the specific patent, claimant, jurisdiction, claims, and settlement terms.

How does naproxen sodium PM compare with ibuprofen PM products?

Factor	Naproxen sodium PM	Ibuprofen PM
NSAID duration	Generally longer-acting	Generally shorter-acting
Typical nighttime positioning	Longer overnight analgesia	Flexible pain-relief positioning
Sleep-aid component	Often diphenhydramine	Often diphenhydramine
Consumer tradeoff	Longer duration, NSAID safety considerations	Shorter duration, different NSAID risk profile
Formulation opportunity	High-dose compact caplet and stability	Lower-dose tablet and rapid-release formats
Patent strength	Usually weak for conventional OTC products	Usually weak for conventional OTC products

The comparison is commercially relevant because consumers may select on duration, price, brand familiarity, tablet size, and morning alertness rather than active ingredients alone.

Key Takeaways

• Naproxen sodium PM is generally a nighttime combination of naproxen sodium and diphenhydramine.
• The strongest excipient platform is a low-moisture immediate-release tablet using robust flow, compression, disintegration, and stability controls.
• Conventional active-ingredient and formulation protection is likely weak because both actives and standard excipients are established.
• OTC monograph compliance, rather than Orange Book exclusivity, is the central U.S. regulatory pathway for ordinary products.
• Paragraph IV litigation is usually not the principal entry mechanism for a monograph-compliant OTC product.
• The best commercial opportunities are private label, retailer licensing, premium packaging, smaller tablets, softgels, and supply-chain cost reduction.
• A differentiated formulation needs measurable performance advantages to support patent protection or premium pricing.
• Regulatory and commercial diligence should focus on NSAID warnings, diphenhydramine sedation, formulation stability, packaging, and trademark clearance.

FAQs

Can naproxen sodium PM be formulated as a softgel?

Yes. A softgel can improve swallowability and support a liquid-filled dosage form, but compatibility, fill homogeneity, shell stability, leakage, and dissolution must be established. The formulation may require suspension or solution technology because naproxen sodium and diphenhydramine citrate have different solubility and stability characteristics.

Is a sustained-release naproxen sodium PM product commercially attractive?

It can be, particularly for overnight pain duration, but sustained release increases development and regulatory complexity. The sleep-aid component may remain immediate release while naproxen is released over a longer period. This creates potential formulation differentiation but also raises dose-dumping, safety, and claim-substantiation issues.

Which excipient is most important for rapid naproxen sodium PM dissolution?

The superdisintegrant system is usually central, but performance depends on the complete formulation. Compression force, lubricant level, tablet porosity, particle size, and coating weight can materially change dissolution.

Can a naproxen sodium PM product use a proprietary excipient?

Yes. A proprietary co-processed excipient or delivery system can support differentiation if it improves manufacturing or product performance. Its commercial value depends on supply security, regulatory acceptability, cost, and whether the formulation claims are difficult to design around.

Is naproxen sodium PM suitable for chronic insomnia or chronic pain?

No. The combination is positioned for occasional nighttime use associated with minor aches and pains. Repeated use raises safety concerns from both naproxen and diphenhydramine and conflicts with the product’s OTC labeling framework [1-3].

References

1. Bayer HealthCare LLC. (n.d.). Aleve PM: Drug Facts label. DailyMed. https://dailymed.nlm.nih.gov/

2. U.S. Food and Drug Administration. (2024). 21 C.F.R. Part 343: Internal analgesic, antipyretic, and antirheumatic drug products for over-the-counter human use. Electronic Code of Federal Regulations. https://www.ecfr.gov/

3. U.S. Food and Drug Administration. (2024). 21 C.F.R. Part 329: Over-the-counter drug products intended for oral ingestion. Electronic Code of Federal Regulations. https://www.ecfr.gov/

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA, Center for Drug Evaluation and Research. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book