List of Excipients in Branded Drug HYDROXYZINE PAMOATE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Greenstone LLC	HYDROXYZINE PAMOATE	hydroxyzine pamoate	59762-5420	D&C RED NO. 33
Greenstone LLC	HYDROXYZINE PAMOATE	hydroxyzine pamoate	59762-5420	D&C YELLOW NO. 10
Greenstone LLC	HYDROXYZINE PAMOATE	hydroxyzine pamoate	59762-5420	FD&C GREEN NO. 3
Greenstone LLC	HYDROXYZINE PAMOATE	hydroxyzine pamoate	59762-5420	FD&C YELLOW NO. 6
Greenstone LLC	HYDROXYZINE PAMOATE	hydroxyzine pamoate	59762-5420	MAGNESIUM STEARATE

Generic Drugs Containing HYDROXYZINE PAMOATE

Company	Ingredient	NDC	Excipient
Amneal Pharmaceuticals of New York LLC	hydroxyzine pamoate	0115-1670	D&C YELLOW NO. 10
Amneal Pharmaceuticals of New York LLC	hydroxyzine pamoate	0115-1670	FD&C BLUE NO. 1
Amneal Pharmaceuticals of New York LLC	hydroxyzine pamoate	0115-1670	FERROSOFERRIC OXIDE
Amneal Pharmaceuticals of New York LLC	hydroxyzine pamoate	0115-1670	GELATIN
Amneal Pharmaceuticals of New York LLC	hydroxyzine pamoate	0115-1670	MAGNESIUM STEARATE

What are the Most Frequently-Used Excipients in HYDROXYZINE PAMOATE?

# Of NDCs	Excipient
1	ACID YELLOW 3
3	ALCOHOL
4	ALUMINUM OXIDE
18	AMMONIA
14	ANHYDROUS LACTOSE

Hydroxyzine Pamoate Excipient Strategy and Commercial Opportunities

Last updated: August 21, 2026

Hydroxyzine pamoate is an established, low-cost generic antihistamine and anxiolytic with limited active-ingredient patent protection. Commercial value is concentrated in formulation execution: capsule manufacturability, dissolution control, differentiated pediatric or geriatric delivery, excipient tolerability, supply reliability, and regulatory positioning. The strongest opportunities are likely to involve improved oral delivery rather than new chemical patents.

What is the pharmaceutical profile of hydroxyzine pamoate?

Hydroxyzine pamoate is the pamoate salt of hydroxyzine, a first-generation H1 antihistamine. U.S. labeling identifies oral capsules as treatment for anxiety, symptomatic relief of pruritus, and preoperative sedation.[1]

Attribute	Hydroxyzine pamoate
Active ingredient	Hydroxyzine pamoate
Therapeutic class	First-generation antihistamine; anxiolytic
Common brand reference	Vistaril
Typical dosage forms	Hard gelatin capsules; historical oral solid products
Administration	Oral
Primary commercial market	Generic prescription products
Salt characteristics	Poorly water-soluble pamoate salt
Key formulation issue	Uniform dispersion and dissolution of a low-solubility active
Main regulatory route for equivalent capsules	Abbreviated New Drug Application
Biosimilar relevance	None; this is a small-molecule drug
Patent profile	Legacy product with no meaningful active-ingredient patent barrier expected to restrict ordinary generic competition

Hydroxyzine pamoate is distinct from hydroxyzine hydrochloride. The two salts cannot automatically be treated as interchangeable for regulatory, pharmaceutical-equivalence, or labeling purposes. Hydroxyzine hydrochloride is generally more suitable for aqueous liquid development, while hydroxyzine pamoate is commercially established in capsule form.

What excipients are used in hydroxyzine pamoate capsules?

U.S. product labels identify excipient systems that commonly include starches, lactose, magnesium stearate, gelatin, colorants, and other capsule or manufacturing components, depending on the manufacturer and strength.[2,3] Generic formulations vary.

A typical excipient architecture has four functional layers:

Formulation function	Candidate excipient classes	Commercial purpose
Bulking and dose uniformity	Lactose, microcrystalline cellulose, dibasic calcium phosphate, pregelatinized starch	Provides capsule fill mass and improves blend uniformity
Disintegration	Crospovidone, croscarmellose sodium, sodium starch glycolate, starch	Promotes capsule plug breakup and powder dispersion
Lubrication	Magnesium stearate, sodium stearyl fumarate, stearic acid	Supports capsule filling and reduces equipment adhesion
Flow and anti-caking	Colloidal silicon dioxide, talc	Improves powder movement and blend handling
Capsule shell	Gelatin or hydroxypropyl methylcellulose	Provides unit-dose containment and patient acceptability
Appearance	Approved colorants, titanium dioxide where permitted	Supports strength differentiation and product identification

The excipient selection cannot be separated from particle size, crystal form, bulk density, electrostatic behavior, and the target dissolution profile. A formulation that has acceptable assay but poor powder segregation can create content-uniformity risk, particularly at lower strengths.

Which excipient properties matter most for hydroxyzine pamoate?

Solubility and dissolution

Hydroxyzine pamoate has limited water solubility relative to more soluble salts. The formulation therefore needs rapid capsule rupture, effective wetting, and adequate dispersion of the active particles. Simply increasing disintegrant concentration may not resolve dissolution if the active remains hydrophobic or agglomerated.

Potential development tools include:

• Reduced active-particle size, subject to agglomeration control.
• Wetting agents at levels compatible with safety and capsule performance.
• Hydrophilic fillers that improve powder penetration by dissolution media.
• Granulation approaches that reduce segregation without creating dense, slow-wetting granules.
• Surfactant-assisted dispersion where justified by compatibility and regulatory precedent.
• Solid-dispersion or lipid-based systems for differentiated products, though these may require a more complex regulatory pathway.

The key commercial point is that dissolution enhancement has value only if it produces a meaningful clinical, regulatory, or manufacturing benefit. A technically superior dissolution profile alone may not justify a premium in a mature generic market.

Blend uniformity and capsule filling

Hydroxyzine pamoate formulations must control:

• Active-to-excipient density differences.
• Particle-size distribution.
• Electrostatic charging.
• Powder cohesion.
• Lubricant overmixing.
• Hopper segregation.
• Fill-weight variation.

Direct blending may be adequate for a robust high-dose formulation but can become less attractive when the active represents a small fraction of the capsule fill. Ordered mixing, dry granulation, or carrier-based dilution may improve uniformity.

Magnesium stearate is widely used but can reduce wetting and slow dissolution when over-lubrication occurs. Sodium stearyl fumarate may offer a different lubrication profile, but substitution requires comparative process and dissolution data.

Capsule-shell moisture

Gelatin capsules are sensitive to environmental moisture and temperature. Hydroxypropyl methylcellulose capsules can provide an alternative for manufacturers seeking:

• Lower dependence on gelatin supply chains.
• Vegetarian positioning.
• Different moisture behavior.
• Reduced interaction with hygroscopic fills.
• Improved alignment with certain global-market requirements.

The shell choice affects disintegration, brittleness, sealing, printing, packaging, and stability. It is not a simple excipient substitution.

Lactose and allergen positioning

Lactose is a common capsule filler, but lactose-free products can target patients with perceived excipient sensitivity, institutional formularies, and certain contract-manufacturing requirements. A lactose-free formulation may use microcrystalline cellulose, mannitol, starch, or dibasic calcium phosphate.

The commercial opportunity is niche rather than mass-market. Patients with true lactose intolerance generally tolerate the small quantities present in many tablets and capsules, but excipient disclosure and customer preference still influence purchasing decisions.

What formulations are protected or commercially differentiated for hydroxyzine pamoate?

Hydroxyzine pamoate has limited opportunity for conventional formulation-patent protection because the molecule and capsule product have been marketed for decades. New intellectual property would more likely cover a specific delivery system, manufacturing process, composition range, or combination of excipients.

Potential formulation concepts include:

Product concept	Technical rationale	Commercial assessment
Rapid-dissolution capsule	Improves wetting and disintegration of the pamoate salt	Moderate value if bioequivalence is achievable and manufacturing remains simple
Sprinkle capsule	Allows administration with soft food	Potential pediatric and geriatric positioning; requires stability and content-uniformity work
Orally disintegrating dosage form	Addresses swallowing difficulty	Formulation complexity is high because the pamoate salt is poorly soluble and may have taste issues
Oral suspension	Enables dose flexibility	Hydroxyzine pamoate is a difficult candidate because of low solubility and sedimentation risk
Lactose-free capsule	Removes a frequently disclosed excipient	Useful for institutional or targeted channels, but unlikely to create broad pricing power
HPMC capsule	Supports vegetarian and supply-chain positioning	Moderate differentiation with manageable technical risk
Modified-release product	Could reduce dosing frequency or sedation peaks	Requires substantial pharmacokinetic and clinical justification; commercial opportunity is uncertain
Unit-dose blister	Improves adherence, portability, and institutional handling	Low technical risk and potentially useful for specialty distribution

A new patent would need more than a list of routine excipients. Stronger protection would require a defined composition and measurable performance, such as a narrow dissolution profile, improved stability, reduced degradation, or a manufacturing step that produces an unexpected result.

When does hydroxyzine pamoate lose exclusivity?

Hydroxyzine pamoate is already a mature generic product. The relevant commercial question is not the expiration of an active-ingredient patent but the absence of a meaningful remaining exclusivity barrier for standard capsules.

U.S. FDA exclusivity and Orange Book status

The original Vistaril product was approved decades ago. Generic hydroxyzine pamoate capsules have been marketed for many years, and the product is generally treated as an established generic opportunity rather than a protected branded product.[2,4]

The FDA Orange Book remains the controlling source for current reference-listed-drug status, therapeutic-equivalence evaluations, patent listings, and exclusivity entries. Patent listings can change as products are discontinued, transferred, or updated. A commercial filing should therefore rely on the current Orange Book record for the specific strength and dosage form rather than on historical brand claims.[4]

There is no biosimilar exclusivity framework for hydroxyzine pamoate. It is a small-molecule drug regulated through the generic-drug pathway.

Patent expiration and generic entry

For ordinary hydroxyzine pamoate capsules, commercial entry risk is driven primarily by:

• ANDA approval timing.
• Paragraph IV certification, if a listed patent is relevant.
• Bioequivalence results.
• Manufacturing readiness.
• API and excipient supply.
• State and federal purchasing contracts.
• Price erosion after multiple approvals.

Because the product is mature, a new entrant should assume substantial price competition. A routine capsule is unlikely to support durable premium pricing unless it has a distribution advantage, supply reliability, a differentiated label, or a contract-manufacturing niche.

Are Paragraph IV challenges relevant to hydroxyzine pamoate?

Paragraph IV litigation is generally more relevant to recently approved products with unexpired Orange Book patents. For a legacy hydroxyzine pamoate capsule, the probability that a new entrant faces a commercially material patent challenge is lower than for a protected branded medicine.

A Paragraph IV assessment should still examine:

1. The current reference-listed drug.
2. Any active Orange Book patent entries.
3. Whether the proposed product uses the same dosage form and strength.
4. Whether a formulation or method-of-use patent is listed.
5. Whether the applicant relies on a different formulation under a 505(b)(2) pathway.
6. Whether any patent dispute affects launch timing.

The relevant risk is usually regulatory and commercial rather than patent-based. Publicly available information does not establish a current, material nationwide patent injunction affecting standard hydroxyzine pamoate capsules.

What FDA regulatory pathway is most suitable?

ANDA for equivalent capsules

An ANDA is the most direct route for a product that matches the reference drug in dosage form, strength, route of administration, and relevant pharmaceutical characteristics. The applicant must demonstrate bioequivalence and satisfy requirements for chemistry, manufacturing, controls, labeling, and facility compliance.[5]

This route is generally preferable when the commercial objective is a conventional generic capsule.

505(b)(2) for differentiated delivery

A 505(b)(2) application may be considered for a materially different product, such as:

• A novel oral suspension.
• A sprinkle product.
• An orally disintegrating formulation.
• A modified-release system.
• A dosage form with a new administration method.

The regulatory burden is higher because the applicant may need additional bridging, pharmacokinetic, safety, or clinical information. A 505(b)(2) strategy is most defensible where the formulation solves a clear administration problem that the conventional capsule does not address.

Compendial and quality considerations

Development should align with applicable USP requirements for dosage-unit uniformity, dissolution, disintegration, impurities, microbial quality, and capsule performance.[6] The sponsor also needs control strategies for:

• Hydroxyzine-related impurities.
• Pamoate-related degradation or interaction products.
• Residual solvents.
• Water activity and capsule-shell moisture.
• Photostability and packaging compatibility.
• Extractables and leachables where liquid or specialty packaging is used.

How strong is the patent estate for hydroxyzine pamoate?

The patent estate is weak for standard capsules and potentially stronger only for genuinely differentiated products.

IP category	Expected strength for conventional capsule	Opportunity for new entrant
Hydroxyzine chemical structure	Low	None for ordinary generic protection
Pamoate salt itself	Low	Limited unless a new solid form or process is identified
Standard capsule composition	Low	Routine substitutions are difficult to protect broadly
Novel excipient ratio	Low to moderate	Possible, but claims may be vulnerable as obvious
Controlled particle-size formulation	Moderate	More defensible with reproducible performance data
Novel suspension or dispersible system	Moderate	Potentially stronger if clinically useful
Manufacturing process	Moderate	Useful for operational protection, subject to ease of design-around
Method of use	Low for established indications	Limited scope unless a genuinely new indication is developed
Packaging or device	Low to moderate	Can support differentiation but rarely blocks all competitors

Patentability is likely to depend on unexpected performance, not merely the selection of known pharmaceutical excipients.

What commercial opportunities exist for hydroxyzine pamoate?

1. Supply-reliable generic capsules

The clearest opportunity is dependable supply of existing strengths. Generic shortages, contract-manufacturing interruptions, API sourcing problems, and customer-service failures can create openings even in low-margin markets.

A supplier should prioritize:

• Multiple qualified API sources.
• Dual-source capsule shells.
• Flexible lactose and lactose-free platforms.
• Robust filling across different production lines.
• Institutional packaging.
• Reliable documentation for pharmacy and hospital buyers.

2. Excipient-restricted products

Lactose-free, gelatin-free, colorant-reduced, or low-allergen products can target selected formularies and pharmacy channels. These products are unlikely to command broad premium pricing, but they may improve contract eligibility.

3. Pediatric and geriatric delivery

The capsule is poorly suited to patients who cannot swallow solid dosage forms. A sprinkle capsule, dispersible powder, or carefully engineered suspension could address this limitation.

The principal technical risks are:

• Dose uniformity after partial administration.
• Taste and mouthfeel.
• Sedimentation or resuspension.
• Chemical stability in water-based systems.
• Preservative compatibility.
• Caregiver handling errors.
• Accurate measurement across dose volumes.

Hydroxyzine hydrochloride may be a more practical starting salt for an aqueous product, but that would create a different regulatory and pharmaceutical-equivalence strategy from hydroxyzine pamoate.

4. Unit-dose and adherence packaging

Blisters, calendar packs, and tamper-evident unit-dose formats could support pharmacy, long-term-care, and travel markets. Packaging differentiation has lower development risk than a novel delivery system but limited exclusionary power.

5. Contract development and manufacturing

Hydroxyzine pamoate can fit a portfolio of mature oral solids requiring:

• Low-cost capsule filling.
• Flexible batch sizes.
• Multiple label and packaging configurations.
• Rapid scale-up.
• Alternate excipient platforms.

The opportunity is operational rather than patent-driven.

What generic launch risks exist for hydroxyzine pamoate?

Risk	Impact	Mitigation
Low market price	Compresses return on formulation investment	Use platform manufacturing and selective strengths
Multiple approved generics	Increases substitution pressure	Compete on supply, packaging, and contract access
Poor dissolution	Can delay approval or create post-approval risk	Develop particle-size, wetting, and disintegration controls early
Blend segregation	Creates content-uniformity failures	Use engineered particle-size distribution and validated blending
Capsule-shell variability	Affects disintegration and stability	Qualify multiple shell suppliers and define incoming controls
Pamoate low solubility	Limits liquid and ODT options	Consider salt, particle engineering, or alternate dosage-form strategy
Sedation and anticholinergic effects	Limits broad consumer positioning	Maintain prescription-channel focus and compliant labeling
QT-prolongation concerns	Can influence prescribing and safety review	Avoid promotional claims that minimize labeled risks
API concentration risk	Can interrupt supply	Establish qualified secondary sources
Formulation overengineering	Raises cost without pricing benefit	Tie each excipient innovation to a measurable commercial outcome

Hydroxyzine labeling includes warnings concerning drowsiness and QT-interval prolongation, among other precautions.[1] Excipient innovation does not remove those active-ingredient risks.

How does hydroxyzine pamoate compare with hydroxyzine hydrochloride?

Factor	Hydroxyzine pamoate	Hydroxyzine hydrochloride
Common commercial use	Capsules and oral solid products	Tablets, capsules, and liquid-oriented development
Aqueous solubility	Lower	Generally more suitable for aqueous systems
Capsule opportunity	Established	Established but less differentiated by salt
Liquid opportunity	Technically difficult as pamoate	More practical starting point
Taste-masking burden	Relevant for dispersible products	Relevant, but salt selection may simplify dissolution
Generic competition	Mature	Mature
Formulation IP opportunity	Particle engineering, capsule systems, specialty delivery	Liquid stability, taste masking, modified delivery
Regulatory strategy	ANDA for equivalent capsules; 505(b)(2) for major innovation	Same general distinction

The salts should not be treated as interchangeable in a development plan. A product designed around hydroxyzine hydrochloride may require a different regulatory comparison, labeling analysis, and bioequivalence strategy.

Which companies are challenging hydroxyzine pamoate?

Hydroxyzine pamoate is supplied by multiple generic manufacturers and marketing organizations. The competitive set can change by strength, dosage form, channel, and national market. Competition is generally based on price, availability, contract terms, and manufacturing reliability rather than active patent challenges.

A current company-by-company ranking requires live FDA product records, market-share data, and procurement information. Public sources do not provide a single reliable, current market-share table covering all hydroxyzine pamoate manufacturers and private-label distributors.

What revenue exposure does hydroxyzine pamoate create?

Hydroxyzine pamoate is unlikely to create substantial branded-drug revenue exposure because the product is mature and generic. Revenue potential is more relevant at the portfolio level.

Commercial returns can come from:

• High-volume, low-cost capsule manufacturing.
• Contract supply agreements.
• Institutional and long-term-care packaging.
• Reliable availability during competitor shortages.
• Specialty formulations with limited direct competition.
• Bundling with other mature central-nervous-system or allergy products.

A standalone premium formulation must overcome generic substitution and low patient willingness to pay. A manufacturer should model value using contribution margin, approval cost, expected annual volume, price erosion, and supply reliability rather than relying on historical branded sales.

Key Takeaways

• Hydroxyzine pamoate is a mature generic drug with limited practical patent protection for standard capsules.
• The main technical challenge is formulating a poorly water-soluble pamoate salt into a uniform, rapidly disintegrating oral solid.
• Excipients should be selected around blend uniformity, wetting, dissolution, capsule-shell performance, and supply resilience.
• Lactose-free, gelatin-free, unit-dose, and geriatric-friendly products offer targeted commercial opportunities.
• Pediatric and liquid products may be more practical with hydroxyzine hydrochloride, but that would require a distinct regulatory strategy.
• An ANDA is generally the most efficient route for an equivalent capsule. A 505(b)(2) pathway is more suitable for a materially different delivery system.
• The strongest new IP would likely relate to a defined formulation, particle-engineering method, process, or delivery system with measurable unexpected performance.
• Generic launch risk is primarily price erosion, manufacturing execution, supply interruption, and dissolution performance, not patent litigation.
• Hydroxyzine pamoate has no biosimilar risk because it is a small-molecule drug.
• Commercial returns are more likely to arise from manufacturing scale and niche differentiation than from a premium branded strategy.

FAQs About Hydroxyzine Pamoate Formulation and Commercialization

Can hydroxyzine pamoate be developed as an oral liquid?

Yes, but the low aqueous solubility of the pamoate salt creates suspension, sedimentation, redispersibility, preservative, taste, and dose-uniformity challenges. Hydroxyzine hydrochloride may offer a more practical starting point for an aqueous product.

Is a lactose-free hydroxyzine pamoate capsule commercially attractive?

It can serve pharmacy, institutional, and excipient-sensitive channels. The opportunity is targeted because lactose-free status alone is unlikely to support a large price premium in a heavily genericized market.

Can a new hydroxyzine pamoate capsule receive formulation-patent protection?

Potentially, but routine substitution of fillers, lubricants, or disintegrants is unlikely to produce strong broad claims. Patent value would improve if the formulation demonstrates unexpected dissolution, stability, bioavailability, or manufacturing performance.

Does hydroxyzine pamoate have biosimilar competition?

No. Hydroxyzine pamoate is a small-molecule drug. Competition occurs through generic-drug pathways, not biosimilar approval.

What is the most defensible product concept for a new entrant?

A supply-reliable, bioequivalent capsule with a robust excipient platform is the lowest-risk concept. A sprinkle or geriatric-friendly product offers greater differentiation but carries materially higher formulation and regulatory risk.

References

1. U.S. Food and Drug Administration. (2024). Vistaril (hydroxyzine pamoate) prescribing information. FDA labeling database.

2. Pfizer Laboratories. (n.d.). Vistaril hydroxyzine pamoate capsules prescribing information. Product labeling.

3. DailyMed. (n.d.). Hydroxyzine pamoate capsule: Product labeling and inactive ingredients. U.S. National Library of Medicine.

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. Orange Book.

5. U.S. Food and Drug Administration. (2024). Abbreviated new drug application submissions: Content and format. FDA guidance and regulatory resources.

6. United States Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary. USP.