List of Excipients in Branded Drug IBUPROFEN AND DIPHENHYDRAMINE HCL

Generic Drugs Containing IBUPROFEN AND DIPHENHYDRAMINE HCL

Company	Ingredient	NDC	Excipient
Walgreens	ibuprofen, diphenhydramine hcl	0363-0665	FD&C BLUE NO. 1
Walgreens	ibuprofen, diphenhydramine hcl	0363-0665	FD&C RED NO. 40
Walgreens	ibuprofen, diphenhydramine hcl	0363-0665	GELATIN
Walgreens	ibuprofen, diphenhydramine hcl	0363-0665	POLYETHYLENE GLYCOL

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

# Of NDCs	Excipient
2	D&C RED NO. 33
5	FD&C BLUE NO. 1
3	FD&C RED NO. 40
5	GELATIN

Ibuprofen and Diphenhydramine HCl Excipient Strategy and Commercial Opportunities

Last updated: August 8, 2026

Ibuprofen and diphenhydramine HCl combination products occupy an established OTC segment for nighttime pain relief. The commercial opportunity is primarily formulation-led rather than molecule-led. Ibuprofen provides analgesic and antipyretic activity, while diphenhydramine HCl provides sedating antihistamine activity used in nighttime products. The highest-value opportunities are liquid-filled capsules, fast-dissolving tablets, age-appropriate liquids, lower-sedation positioning, dose convenience, and differentiated packaging.

The combination has limited expected composition-of-matter patent risk because both active ingredients are long-established generic substances. Regulatory execution, excipient compatibility, dissolution, sensory performance, labeling, and manufacturing reliability are more important barriers than active-ingredient exclusivity.

What is the regulatory status of ibuprofen and diphenhydramine HCl combinations?

Ibuprofen and diphenhydramine HCl products are generally regulated as OTC combination products when the formulation and labeling comply with applicable FDA OTC monograph conditions.

Ibuprofen is permitted as an OTC internal analgesic and antipyretic under the FDA analgesic, antipyretic, and antirheumatic monograph framework. Diphenhydramine is permitted as an OTC nighttime sleep-aid active under the FDA nighttime sleep-aid monograph framework, subject to dosage, labeling, and warning requirements. The combination must satisfy the conditions applicable to each active and to the combined indication. [1], [2]

A commercial product may use diphenhydramine citrate rather than diphenhydramine HCl. The salt choice affects dose expression, solubility, taste, hygroscopicity, and labeling. A formulation using 25 mg diphenhydramine HCl is not directly equivalent by mass to one using 38 mg diphenhydramine citrate, even though the products may deliver comparable diphenhydramine activity.

Typical active-ingredient configurations

Product configuration	Typical active profile	Commercial implication
Ibuprofen caplet plus diphenhydramine HCl	Ibuprofen 200 mg; diphenhydramine HCl commonly 25 mg	Lowest-cost solid-dose platform
Liquid-filled softgel	Ibuprofen 200 mg; diphenhydramine salt commonly equivalent to approximately 25 mg diphenhydramine	Premium appearance, rapid disintegration, higher manufacturing complexity
Tablet or caplet	Same active range	Suitable for private-label and mass retail
Oral liquid	Lower dose per measured volume	Pediatric and adult liquid opportunity, but labeling and safety constraints are significant
Powder or sachet	Unit-dose ibuprofen and diphenhydramine	Convenient format, but taste and moisture control are difficult

The well-known Advil PM product uses ibuprofen with diphenhydramine citrate rather than diphenhydramine HCl. A manufacturer developing an HCl-based product should treat salt substitution as a formulation and regulatory design choice, not as a simple copy of the citrate product. [3]

What excipient strategy is appropriate for ibuprofen and diphenhydramine HCl tablets?

A conventional immediate-release tablet should prioritize rapid disintegration, consistent dissolution, low weight variability, and moisture control.

Core excipient functions

Formulation function	Common excipient classes	Key development issue
Dilution and compressibility	Microcrystalline cellulose, lactose, mannitol, dibasic calcium phosphate	Ibuprofen has poor flow and limited compressibility
Binder	Povidone, copovidone, pregelatinized starch, hydroxypropyl cellulose	Excess binder can slow dissolution
Disintegrant	Croscarmellose sodium, crospovidone, sodium starch glycolate	Must overcome hydrophobic ibuprofen behavior
Lubricant	Magnesium stearate, sodium stearyl fumarate	Over-lubrication can impair tablet strength and dissolution
Glidant	Colloidal silicon dioxide	Improves flow but can alter blend segregation
Taste modifier	Sucralose, acesulfame potassium, flavors, film coating	Diphenhydramine HCl is bitter and may produce throat irritation
Film coating	Hypromellose, polyvinyl alcohol, polyethylene glycol, titanium dioxide or permitted colorants	Supports identification, swallowing, and taste masking
Buffer or microenvironment modifier	Citrate, phosphate, carbonate systems	Can influence ibuprofen dissolution and stability

Ibuprofen is a weak acid with low aqueous solubility in its unionized form. The formulation should therefore avoid excessive hydrophobic lubricant and should use a disintegrant system capable of exposing ibuprofen particles rapidly to dissolution media. Crospovidone or croscarmellose sodium can support rapid tablet breakup, while excessive polymeric binder may delay release.

Diphenhydramine HCl is more water-soluble than ibuprofen and can create a blend-uniformity challenge when combined with a poorly flowing, hydrophobic ibuprofen powder. Granulation, ordered mixing, or carrier-based premixing may improve content uniformity. A formulation should be evaluated for segregation during hopper transfer, compression, dedusting, and packaging.

Direct compression versus granulation

Direct compression offers lower process cost and fewer unit operations. It is attractive for private-label and high-volume products if the active powders have suitable particle-size distribution and flow characteristics.

Wet granulation can improve content uniformity, flow, and tablet strength, but it introduces water exposure and drying requirements. The process must control:

• Ibuprofen polymorphic and particle-size behavior.
• Diphenhydramine HCl migration during drying.
• Residual moisture.
• Granule density and dissolution.
• Interaction with lubricant and coating systems.

Dry granulation is a useful compromise when the blend requires improved flow but the product is moisture-sensitive or when a water-free process is preferred.

What excipients are best for liquid-filled softgels?

Softgels are commercially attractive because they differentiate the product from standard tablets and support a premium retail price. The liquid fill must dissolve or uniformly suspend both active ingredients and remain compatible with the gelatin or non-gelatin shell.

A key technical issue is the different solubility behavior of ibuprofen and diphenhydramine HCl. Ibuprofen is poorly soluble in many aqueous systems, while diphenhydramine HCl is comparatively soluble. A clear solution may require a cosolvent or solubilization system, but aggressive solvents can weaken the shell or accelerate shell migration.

Potential fill components include:

• Polyethylene glycol, commonly used as a hydrophilic vehicle.
• Propylene glycol, subject to concentration and tolerability limits.
• Glycerin, primarily as a plasticizer or cosolvent.
• Polysorbates or other surfactants, where justified by compatibility data.
• Povidone or related solubilizers.
• Buffering agents to control pH.
• Antioxidants where oxidation risk is demonstrated.

The development target should be a stable solution or fine suspension with controlled sedimentation, low fill viscosity variation, and acceptable shell integrity. Gelatin cross-linking, leakage, brittleness, and active migration must be assessed under accelerated and long-term conditions.

A non-gelatin shell based on hypromellose can create a vegan or religious-compliance positioning, but it changes fill compatibility, sealing conditions, oxygen transmission, and manufacturing cost.

What formulations are protected by patents?

The active ingredients have no meaningful modern composition-of-matter exclusivity. Patent value is more likely to arise from:

• Liquid-filled capsule compositions.
• Rapid-release ibuprofen systems.
• Taste-masked diphenhydramine products.
• Bilayer or multilayer tablets.
• Abuse-deterrent or child-resistant delivery systems.
• Stabilized liquid formulations.
• Specific excipient ratios and manufacturing processes.
• Unit-dose packaging and moisture-barrier systems.

OTC monograph products typically do not have the same Orange Book patent-listing profile as prescription NDA products. The FDA Orange Book primarily identifies approved prescription drug products, relevant patents, and regulatory exclusivity. A standard OTC monograph product generally does not receive a conventional Orange Book patent-blocking position merely because its formulation is sold commercially. [4]

A formulation patent can still create commercial litigation risk if it claims a narrow composition, process, dosage form, or physical property. The practical risk depends on claim scope, enforceability, expiration, prosecution history, and whether a competitor’s process actually practices the claims.

When does ibuprofen and diphenhydramine lose exclusivity?

The active ingredients already have generic availability. There is no expected loss-of-exclusivity event comparable to a prescription drug’s patent cliff.

Exclusivity category	Expected position
Ibuprofen composition of matter	Expired
Diphenhydramine HCl composition of matter	Expired
Standard OTC monograph pathway	No product-specific exclusivity comparable to a new NDA
Brand formulation patents	Product-specific and claim-dependent
Trade dress and trademarks	Potentially valuable but separate from pharmaceutical exclusivity
Pediatric exclusivity	Not inherent to a standard adult OTC combination
Orphan exclusivity	Not applicable to the ordinary indication

Generic and private-label entry is therefore commercially feasible. The main barriers are formulation performance, retailer qualification, manufacturing scale, product liability, advertising, and distribution rather than active-ingredient exclusivity.

What generic entry risks exist for ibuprofen and diphenhydramine HCl?

Generic entry risk is high for ordinary immediate-release tablets and caplets. A competitor can use the OTC monograph route if its actives, strengths, dosage form, labeling, and manufacturing controls comply with FDA requirements.

The risk is lower for complex delivery systems, including:

• Clear or near-clear softgel fills.
• Taste-masked oral liquids.
• Rapid-release systems with defined dissolution performance.
• Bilayer tablets separating incompatible components.
• Low-moisture or oxygen-sensitive formulations.
• Products with distinctive unit-dose packaging.

A Paragraph IV challenge is generally more relevant to an approved NDA product with listed patents than to a conventional OTC monograph product. If an innovator obtains approval through an NDA or relies on formulation claims associated with an NDA, a Paragraph IV certification may become relevant. For a standard monograph product, market entry usually turns on monograph compliance and product-specific intellectual property rather than an Orange Book certification dispute. [4], [5]

What manufacturing and IP barriers affect the commercial opportunity?

Manufacturing barriers are moderate for tablets and higher for softgels and liquids.

Tablet manufacturing barriers

The primary risks are blend segregation, poor flow, capping, sticking, low dissolution, and content uniformity. Ibuprofen’s hydrophobicity can complicate dissolution, while diphenhydramine HCl can contribute to electrostatic behavior and blend instability.

A robust tablet process should establish:

1. Particle-size control for both actives.
2. A defined premix strategy.
3. Controlled lubricant addition.
4. Dissolution testing at development and release stages.
5. Packaging that limits moisture uptake.
6. Compression-force ranges that preserve rapid disintegration.

Softgel manufacturing barriers

Softgel products require specialized encapsulation equipment, shell and fill compatibility studies, and tighter control of fill weight and seam integrity. Contract manufacturing capacity can be a constraint, particularly for high-volume private-label programs.

Intellectual-property barriers

The strongest defensible positions are likely to involve measurable technical performance, such as:

• A specified dissolution profile.
• A stable liquid fill over a defined shelf life.
• A narrow particle-size or excipient-ratio claim.
• A defined taste-masking system.
• A manufacturing method that reduces degradation or segregation.

Broad claims covering “ibuprofen and diphenhydramine in a tablet” are less likely to provide durable protection because of extensive prior art and long commercial use.

How does ibuprofen and diphenhydramine compare with competing nighttime analgesics?

Product type	Analgesic	Nighttime active	Main advantage	Main weakness
Ibuprofen plus diphenhydramine	NSAID	Sedating antihistamine	Strong OTC familiarity and broad pain utility	NSAID warnings and next-day sedation concerns
Acetaminophen plus diphenhydramine	Acetaminophen	Sedating antihistamine	Broad consumer recognition	Liver-toxicity dose concerns
Naproxen plus diphenhydramine	NSAID	Sedating antihistamine	Longer analgesic duration	Greater NSAID exposure duration
Ibuprofen alone	NSAID	None	No sedating ingredient	Does not address nighttime sleep demand
Diphenhydramine alone	None	Sedating antihistamine	Sleep-aid positioning	Does not treat pain

Ibuprofen-based products can compete on anti-inflammatory positioning, while acetaminophen combinations may have broader perceived suitability among consumers who avoid NSAIDs. Packaging and labeling should make the active ingredients prominent because consumers may otherwise duplicate ibuprofen, acetaminophen, or diphenhydramine through simultaneous use of multiple OTC products.

What commercial opportunities exist for new formulations?

Premium softgels

Liquid-filled softgels can support higher pricing and differentiation from commodity caplets. The opportunity is strongest where the product provides a clear consumer benefit, such as easier swallowing, rapid disintegration, or compact packaging.

Private-label and retailer brands

The category is suitable for retailer-branded products because the actives are familiar, the indication is easy to communicate, and the OTC monograph pathway can reduce development costs. Margin pressure is high, so packaging efficiency and supply-chain reliability are essential.

Unit-dose travel packaging

Blister packs and single-dose sachets can support travel, e-commerce, and convenience channels. A unit-dose system can also reduce accidental repeat dosing, although the labeling must remain compliant and clear.

Age-appropriate products

Adult nighttime products have stronger commercial precedent than pediatric combinations. Diphenhydramine-containing products require careful age labeling and safety review. A children's product would face greater regulatory, clinical, and liability sensitivity than an adult formulation.

Taste-masked liquids

An oral liquid could target consumers who cannot swallow tablets. The primary development risks are bitter taste, ibuprofen suspension stability, dose uniformity, preservative efficacy, and accidental overuse. A suspension is more practical than a fully dissolved system in many cases, but it requires robust redispersibility and dosing-device validation.

Non-gelatin and clean-label positioning

Hypromellose capsules, reduced-color formulations, and excipient-minimized tablets can address dietary, religious, and consumer-preference segments. These claims have marketing value but do not by themselves create strong pharmaceutical exclusivity.

What is the FDA and Orange Book status of these products?

The relevant FDA framework is the OTC monograph system for internal analgesics and nighttime sleep aids. The FDA’s Drug Facts labeling rules, active-ingredient requirements, warnings, directions, and manufacturing obligations apply to the finished product. [1], [2], [6]

A standard OTC monograph combination should not be assumed to have an Orange Book listing or an Orange Book patent dispute. The Orange Book should be checked for any specific NDA-approved product, while FDA monograph compliance and the USPTO patent database should be used for broader product and formulation analysis. [4], [7]

How strong is the patent estate for ibuprofen and diphenhydramine HCl products?

The estate is weak at the molecule level and potentially moderate at the formulation level.

Patent layer	Expected strength
Active-ingredient patents	Very weak or expired
Basic tablet combination claims	Weak because of prior art
Specific softgel or liquid-fill claims	Moderate if technically narrow
Taste-masking claims	Moderate where supported by objective performance
Manufacturing-process claims	Moderate, depending on process evidence
Packaging and delivery claims	Usually narrow and easy to design around
Brand trademarks and trade dress	Potentially stronger commercially than the drug patent estate

A freedom-to-operate review should focus on live formulation patents, continuation applications, international equivalents, and patents owned by branded OTC manufacturers or specialty delivery companies. Patent expiration dates must be evaluated family by family because continuation claims can expire later than the earliest filing only within statutory limits and may have different enforceability profiles.

Key Takeaways

• Ibuprofen and diphenhydramine HCl have expired active-ingredient exclusivity and are suitable for generic and private-label development.
• The principal regulatory route is OTC monograph compliance, provided the formulation and labeling satisfy FDA requirements.
• Immediate-release tablets have high generic-entry risk and low formulation defensibility.
• Softgels, taste-masked liquids, bilayer tablets, and specialized packaging offer stronger commercial differentiation.
• Ibuprofen’s poor aqueous solubility and hydrophobic behavior are the central excipient and dissolution challenges.
• Diphenhydramine HCl creates taste, blend-uniformity, sedation-labeling, and age-positioning considerations.
• Orange Book and Paragraph IV issues are generally less central for standard OTC monograph products than for NDA-approved products.
• Commercial value is most likely to come from dosage form, retailer access, manufacturing scale, packaging, and consumer positioning.
• The strongest patent opportunities involve narrow formulation, dissolution, stability, or manufacturing claims rather than broad combination claims.

FAQs

Can ibuprofen and diphenhydramine HCl be combined in one OTC tablet?

Yes, provided the active ingredients, strength, dosage form, labeling, warnings, directions, and manufacturing controls comply with applicable FDA requirements.

Is diphenhydramine HCl interchangeable with diphenhydramine citrate?

The salts are not interchangeable by weight. The formulation must account for salt molecular weight, active diphenhydramine equivalent, solubility, taste, and labeling.

Which dosage form offers the best commercial opportunity?

Liquid-filled softgels generally provide the strongest differentiation, while standard caplets offer the lowest manufacturing cost and the highest private-label competition.

Can a new ibuprofen and diphenhydramine product obtain drug exclusivity?

A conventional OTC monograph product normally does not receive prescription-style exclusivity. A novel NDA-approved formulation could create a different regulatory and patent position, depending on the product’s innovation and approval basis.

What is the main technical risk in developing the combination?

The main technical risk is achieving rapid, reproducible ibuprofen dissolution while maintaining blend uniformity, tablet integrity, acceptable taste, and stability of diphenhydramine HCl.

References

1. U.S. Food and Drug Administration. (2024). OTC monograph M013: Internal analgesic, antipyretic, and antirheumatic drug products. https://www.accessdata.fda.gov
2. U.S. Food and Drug Administration. (2024). OTC monograph M010: Sleep aid drug products for over-the-counter human use. https://www.accessdata.fda.gov
3. Haleon. (2024). Advil PM drug facts label. https://www.advil.com
4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book
5. U.S. Food and Drug Administration. (2024). Abbreviated new drug application approvals and patent certifications. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda
6. U.S. Food and Drug Administration. (2024). Over-the-counter drug product labeling requirements. https://www.fda.gov/drugs/drug-approvals-and-databases/over-counter-otc-drug-monograph-system
7. United States Patent and Trademark Office. (2024). Patent Public Search. https://ppubs.uspto.gov/pubwebapp/