List of Excipients in Branded Drug IBUPROFEN AND DIPHENHYDRAMINE CITRATE

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Generic Drugs Containing IBUPROFEN AND DIPHENHYDRAMINE CITRATE

Company	Ingredient	NDC	Excipient
Better Living Brands LLC	ibuprofen and diphenhydramine citrate	21130-228	CARNAUBA WAX
Better Living Brands LLC	ibuprofen and diphenhydramine citrate	21130-228	CROSCARMELLOSE SODIUM
Better Living Brands LLC	ibuprofen and diphenhydramine citrate	21130-228	FD&C BLUE NO. 2
Better Living Brands LLC	ibuprofen and diphenhydramine citrate	21130-228	GLYCERYL DIBEHENATE
Better Living Brands LLC	ibuprofen and diphenhydramine citrate	21130-228	HYPROMELLOSE 2910
Better Living Brands LLC	ibuprofen and diphenhydramine citrate	21130-228	LACTOSE MONOHYDRATE

What are the Most Frequently-Used Excipients in IBUPROFEN AND DIPHENHYDRAMINE CITRATE?

# Of NDCs	Excipient
3	CARNAUBA WAX
1	CELLULOSE, MICROCRYSTALLINE
3	CROSCARMELLOSE SODIUM
3	FD&C BLUE NO. 2
2	GLYCERYL DIBEHENATE
2	HYPROMELLOSE 2910

Ibuprofen and Diphenhydramine Citrate Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: October 20, 2026

Ibuprofen and diphenhydramine citrate is a mature OTC combination used for nighttime relief of minor aches and occasional sleeplessness. The commercial reference product is Advil PM, generally containing ibuprofen 200 mg and diphenhydramine citrate 38 mg, equivalent to diphenhydramine 25 mg per dosage unit.[1] The active ingredients are off-patent, so commercial value depends mainly on formulation performance, brand positioning, manufacturing cost, regulatory execution, and differentiated delivery formats.

The strongest opportunities are in low-cost solid-dose products, softgels, liquid-filled capsules, pediatric or age-limited formulations, and improved-swallowability products. Excipient selection can create practical product differentiation, but excipients alone rarely provide durable exclusion unless incorporated into a novel formulation with defensible performance data.

What is the composition and regulatory status of ibuprofen and diphenhydramine citrate products?

The combination uses two pharmacologically different active ingredients:

Component	Typical amount per unit	Function
Ibuprofen	200 mg	Analgesic and antipyretic NSAID
Diphenhydramine citrate	38 mg	Equivalent to 25 mg diphenhydramine; nighttime sleep-aid component
Dosage form	Caplet, tablet, or capsule	Oral immediate-release delivery

Advil PM is marketed as an OTC nighttime analgesic and sleep-aid product. The labeling directs adults and children age 12 years and older to take two caplets at bedtime, with a maximum of two caplets in 24 hours.[1]

Ibuprofen is regulated under FDA OTC analgesic requirements, while diphenhydramine is regulated under the OTC sleep-aid framework. The combination product’s labeling must address NSAID gastrointestinal, cardiovascular, renal, bleeding, and pregnancy-related risks, as well as diphenhydramine-related sedation, anticholinergic effects, and next-day impairment.[1][2]

Is ibuprofen and diphenhydramine citrate an FDA-approved product?

The marketed Advil PM product has an FDA regulatory history associated with a drug application, while equivalent OTC products may enter the market through different regulatory routes depending on formulation, labeling, and applicable monograph requirements. A sponsor cannot assume that a new combination, strength, dosage form, or indication is covered by an OTC monograph.

A reformulated product may require one of the following:

• Compliance with applicable OTC monograph conditions.
• An abbreviated pathway where an eligible reference product and regulatory basis exist.
• A new drug application or supplemental application.
• FDA review of a formulation or labeling change if the product departs from established conditions.

What excipient strategy is appropriate for ibuprofen and diphenhydramine citrate?

The preferred strategy is an immediate-release formulation that rapidly disintegrates, minimizes ibuprofen’s poor aqueous solubility, controls diphenhydramine citrate’s hygroscopicity, and remains stable under accelerated storage.

Core excipient functions

Formulation objective	Suitable excipient classes	Main development concern
Improve powder flow	Colloidal silicon dioxide, silicified microcrystalline cellulose	Excess glidant can reduce tablet strength
Support direct compression	Microcrystalline cellulose, mannitol, dibasic calcium phosphate	Density and mouthfeel must match target dosage form
Improve disintegration	Crospovidone, croscarmellose sodium, sodium starch glycolate	Excess levels may affect friability or dissolution
Reduce ibuprofen sticking	Stearic acid, sodium stearyl fumarate, magnesium stearate	Lubricant overuse can slow dissolution
Mask taste	Film coating, polymeric coating, sweeteners, flavor systems	Coating may delay release
Control moisture	Low-moisture fillers, barrier film, desiccant packaging	Diphenhydramine citrate may contribute to moisture sensitivity
Improve capsule fill	Spray-dried mannitol, microcrystalline cellulose, silica	Segregation risk from active-excipient density differences
Enable liquid formulation	Suspending agents, wetting agents, sweeteners, buffers	Ibuprofen solubility and taste are difficult constraints

Ibuprofen presents the principal formulation challenge. It is a weak acid with limited water solubility, and its hydrophobic surface can cause poor wetting, sticking, and variable dissolution. Diphenhydramine citrate is more water-compatible but can be hygroscopic and may alter blend flow and compactability.

Which excipients improve ibuprofen dissolution?

The most commercially practical approach is particle engineering rather than aggressive chemical solubilization. Options include:

1. Micronized ibuprofen to increase surface area.
2. Wetting agents such as sodium lauryl sulfate at controlled levels.
3. Hydrophilic carriers such as povidone or low-viscosity polymeric dispersants.
4. Co-processed excipients that improve compaction and disintegration.
5. Solid-dispersion or amorphous approaches where the sponsor can control recrystallization.

Each approach creates different regulatory and patent implications. Micronization is relatively easy to implement but often has limited exclusionary value. A stable amorphous dispersion or defined co-processed system may support stronger intellectual-property claims but requires substantial stability and scale-up work.

What formulations are protected or commercially differentiated?

The active ingredients themselves are mature. Product differentiation is more likely to arise from formulation architecture than from composition of matter.

Immediate-release caplets

Immediate-release caplets are the lowest-risk commercial format. The formulation can use:

• Microcrystalline cellulose as the principal compression aid.
• Crospovidone or croscarmellose sodium for rapid disintegration.
• Colloidal silicon dioxide for flow.
• Magnesium stearate or sodium stearyl fumarate for lubrication.
• A moisture-protective film coat.

The main opportunity is cost reduction, improved dissolution, reduced tablet weight, or improved appearance. These improvements may support a formulation patent only if linked to a defined composition and measurable performance advantage.

Softgels and liquid-filled capsules

Softgels can improve swallowability and provide a premium format. Ibuprofen is commonly formulated in liquid or semisolid systems using polyethylene glycol, propylene glycol, or lipid vehicles. Diphenhydramine citrate creates compatibility and solubility questions because the salt may behave differently from diphenhydramine free base in nonaqueous vehicles.

A softgel strategy must address:

• Active-vehicle solubility.
• Shell compatibility.
• Migration of plasticizers or water.
• Long-term fill-shell interaction.
• Dose uniformity.
• Leakage and oxygen exposure.
• Sedimentation if one active remains suspended.

Softgels may support a more defensible formulation program than standard tablets, but development costs and manufacturing complexity are higher.

Chewables and orally disintegrating products

Chewables and orally disintegrating tablets offer convenience but create a difficult taste-masking problem. Ibuprofen is bitter and diphenhydramine can produce a strong medicinal taste. These formats require coating, ion-exchange resins, polymeric taste masks, or multiparticulate encapsulation.

Potential excipients include:

• Mannitol for cooling mouthfeel.
• Crospovidone for rapid breakup.
• Sucralose or acesulfame potassium for sweetness.
• Flavor systems with high masking capacity.
• Polymer-coated drug particles.
• Ion-exchange resins where regulatory and performance requirements are satisfied.

A palatable, low-water-activity product could target adult consumers who have difficulty swallowing caplets. Pediatric positioning is more restricted because diphenhydramine labeling and safety concerns limit the appropriate population.

Liquid and suspension products

A liquid combination product has a clear convenience advantage but is technically less attractive. Ibuprofen’s water solubility is limited, while diphenhydramine citrate is relatively water-compatible. A suspension would need controlled particle size, wetting, viscosity, sedimentation, and redispersibility.

Potential excipient systems include:

• Suspending polymers such as xanthan gum or cellulose derivatives.
• Wetting agents.
• Buffers.
• Polyols and sweeteners.
• Preservatives where required.
• Flavor and color systems.
• High-barrier packaging.

The principal commercial risks are taste, sedimentation, dose uniformity, microbial control, and packaging volume. A liquid product is more likely to justify formulation-specific intellectual property if it achieves a stable, palatable, homogeneous suspension without excessive viscosity.

When does ibuprofen and diphenhydramine citrate lose exclusivity?

The active ingredients have no meaningful remaining composition-of-matter exclusivity in the United States. The commercial reference product is therefore exposed primarily to:

• Generic and private-label competition.
• Store-brand nighttime pain products.
• Retailer-specific formulations.
• Softgel and capsule alternatives.
• Products using the same actives under different branding.

The relevant exclusivity analysis must distinguish patent rights from regulatory exclusivity. OTC products can remain commercially protected through trademarks, packaging, distribution, and consumer recognition even when active-ingredient patents have expired.

Exclusivity category	Position for this combination
Active-ingredient patent	Mature and not commercially controlling
Original formulation patent	Requires product-specific patent review
Method-of-use patent	Possible but generally limited by established nighttime analgesic use
Orange Book listing	Must be confirmed against the current FDA Orange Book and product record
Regulatory exclusivity	Depends on the specific application and approval history
Trademark protection	Potentially important for Advil PM and related branding
Trade dress	Relevant to packaging and shelf recognition
Manufacturing know-how	Potentially valuable for softgels, suspensions, and taste-masked formats

What is the Orange Book status of Advil PM?

The Orange Book analysis must be conducted at the application and product level. A sponsor should review:

• The FDA Orange Book listing for the relevant application number.
• Patent submissions associated with the reference product.
• Patent expiration dates and use codes.
• Whether listed patents remain active, expired, delisted, or disputed.
• Whether a proposed generic would need a Paragraph IV certification.

A Paragraph IV challenge would require the applicant to assert that a listed patent is invalid, unenforceable, or not infringed. For a mature OTC combination, the more likely competitive pathway may involve a product relying on monograph conditions or a legally permissible equivalent route rather than a conventional Paragraph IV campaign. The exact path depends on the reference product’s regulatory classification and current listing status.[3]

Which companies are challenging or competing with ibuprofen and diphenhydramine citrate products?

The market is fragmented. Competition can come from:

• Generic manufacturers supplying ibuprofen/diphenhydramine products.
• Private-label retailers.
• Branded OTC companies such as Haleon, Kenvue, and Perrigo.
• Contract manufacturers producing retailer-specific caplets or softgels.
• Alternative nighttime analgesic products containing acetaminophen and diphenhydramine.
• Single-ingredient ibuprofen products used with separate sleep aids.

The primary competitive threat is not biosimilar substitution. Ibuprofen and diphenhydramine citrate are small-molecule drugs, so biosimilar rules do not apply. The relevant risks are generic substitution, private-label erosion, brand switching, and format substitution.

What patent litigation and settlement risks exist?

The patent-litigation profile is generally lower than for recently launched prescription drugs because the actives are old and the dominant products are OTC. Litigation risk can still arise from:

• A novel ibuprofen dispersion.
• A softgel fill composition.
• A taste-masked multiparticulate system.
• A suspension with defined rheological properties.
• A manufacturing process that produces a specified dissolution profile.
• Packaging or moisture-control technology.
• A method-of-use claim directed to a narrow patient population or dosing schedule.

Settlement agreements are more relevant if a branded sponsor has enforceable formulation patents and a generic applicant files a Paragraph IV certification. Any settlement would need review for launch dates, licensed entry, supply rights, authorized-generic provisions, and antitrust restrictions.

How strong is the patent estate for this combination?

The baseline patent estate is weak if it consists only of the active ingredients, conventional tablet excipients, or the general use of the combination for nighttime pain. Patent strength improves when claims cover a specific, reproducible technical feature.

Stronger patent categories

• Defined particle-size distribution for ibuprofen.
• A stable amorphous or co-amorphous composition.
• A particular ibuprofen-to-diphenhydramine ratio with improved dissolution.
• A softgel fill that solubilizes or stabilizes both actives.
• A taste-masked multiparticulate system.
• A suspension with defined sedimentation and redispersibility.
• A moisture-control package integrated with the dosage form.
• A process that reliably produces a non-sticking, high-throughput tablet.

Weaker patent categories

• Broad claims to ibuprofen and diphenhydramine together.
• Conventional excipient combinations without unexpected results.
• Routine tablet coatings.
• Generic claims to analgesic and sleep-aid use.
• Formulations defined only by desired outcomes without structural limitations.

The commercial value of a patent depends on claim scope, freedom to operate, reproducibility at commercial scale, and whether a competing manufacturer can design around the claimed excipients or process.

What manufacturing and IP barriers affect commercialization?

The principal manufacturing barriers are practical rather than chemical:

1. Blend uniformity. The two actives differ in dose, density, particle size, and flow.
2. Ibuprofen sticking. Compression tooling and lubricant selection require optimization.
3. Moisture control. Diphenhydramine citrate and certain excipients may increase sensitivity to humidity.
4. Dissolution. Hydrophobic ibuprofen can produce slow or variable release.
5. Softgel compatibility. Fill composition, shell composition, and water migration require long-term evaluation.
6. Taste. Chewables and liquids require more sophisticated masking.
7. Packaging. High-barrier blister or bottle systems may be needed to preserve stability.
8. Scale-up. A laboratory blend that performs well may segregate or fail compression at commercial batch sizes.

These barriers can create trade-secret value even when they do not produce patentable claims. Process controls, supplier qualification, coating parameters, and packaging specifications can reduce manufacturing cost and support consistent product quality.

What commercial opportunities are most attractive?

Opportunity	Market logic	IP potential	Development risk
Low-cost generic caplet	Large, established demand	Low	Low
Premium softgel	Better swallowability and consumer differentiation	Medium	Medium
Fast-dissolving caplet	Convenience and performance positioning	Medium	Medium
Taste-masked chewable	New user experience	Medium to high	High
Oral suspension	Liquid-format differentiation	Medium	High
High-barrier travel pack	Stability and convenience	Low to medium	Low
Private-label retailer product	Distribution and price advantage	Low	Low
Novel ibuprofen dispersion	Dissolution and dose-form innovation	High	High

The most balanced opportunity is a softgel or fast-dissolving caplet with a clear consumer benefit and a controlled manufacturing platform. A standard compressed tablet is easier to launch but has limited pricing power and weak patent differentiation.

How does this combination compare with acetaminophen and diphenhydramine?

Ibuprofen/diphenhydramine and acetaminophen/diphenhydramine products compete for the same nighttime-relief consumer but have different formulation and safety profiles.

Factor	Ibuprofen plus diphenhydramine	Acetaminophen plus diphenhydramine
Analgesic class	NSAID	Non-NSAID analgesic
Main formulation issue	Poor ibuprofen wetting and dissolution	Acetaminophen solubility and high dose load
Major safety messaging	Gastrointestinal, renal, cardiovascular, bleeding risks	Liver toxicity and maximum daily dose
Premium-format opportunity	Strong for softgels and rapid dissolution	Strong for liquids and caplets
Generic competition	High	High
Biosimilar relevance	None	None

Product positioning should avoid implying that either combination is universally safer. Labeling, contraindications, and consumer communication remain central to regulatory risk.

Key Takeaways

• Ibuprofen and diphenhydramine citrate is a mature OTC combination with limited active-ingredient exclusivity.
• The reference dosage is commonly 200 mg ibuprofen plus 38 mg diphenhydramine citrate, equivalent to 25 mg diphenhydramine.
• Formulation value centers on ibuprofen dissolution, moisture control, blend uniformity, taste masking, and softgel compatibility.
• Standard caplets offer the lowest development risk but limited patent strength.
• Softgels, rapid-dissolving products, taste-masked systems, and stable suspensions offer stronger commercial differentiation.
• Biosimilar risk does not apply. Generic, private-label, and format-substitution risks are the relevant threats.
• Patent strength depends on a specific formulation or process supported by unexpected performance and commercial-scale reproducibility.
• Orange Book listings, patent expiration dates, and Paragraph IV exposure must be confirmed against the current FDA product and patent records before launch or litigation decisions.
• The strongest near-term business case is a differentiated softgel or fast-dissolving caplet supported by formulation know-how, high-barrier packaging, and targeted consumer positioning.

FAQs

Can ibuprofen and diphenhydramine citrate be formulated in one liquid product?

Yes, but the product would likely require a suspension or specialized solubilization system because ibuprofen has limited water solubility. Taste, sedimentation, dose uniformity, and preservative strategy are major development constraints.

Is diphenhydramine citrate interchangeable with diphenhydramine hydrochloride?

They are different salts and should not be treated as automatically interchangeable for formulation, equivalence, stability, or regulatory purposes. The labeled amount must be evaluated against diphenhydramine base equivalence.

Can a new excipient combination obtain a patent?

Potentially, but routine combinations of known excipients are vulnerable to obviousness challenges. Patentability is stronger when the composition produces an unexpected dissolution, stability, taste, or manufacturing result.

Is a softgel automatically faster acting than a caplet?

No. A softgel can improve wetting or solubilization, but onset depends on the fill formulation, drug release, dissolution, gastric conditions, and pharmacokinetic performance.

What is the largest commercial risk for a new ibuprofen and diphenhydramine product?

The largest risk is weak differentiation. A conventional caplet may face immediate price competition from generic and private-label products unless it has a measurable performance, convenience, packaging, or brand advantage.

References

1. U.S. Food and Drug Administration. (n.d.). Advil PM: Drug facts label and labeling information. Drugs@FDA and product labeling database.

2. U.S. Food and Drug Administration. (2022). OTC monograph M013: Internal analgesic, antipyretic, and antirheumatic drug products. FDA.

3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. 44th ed. Orange Book. FDA.

4. U.S. Food and Drug Administration. (2023). OTC monograph M012: Nighttime sleep-aid drug products. FDA.