List of Excipients in Branded Drug VISTARIL

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Pfizer Laboratories Div Pfizer Inc	VISTARIL	hydroxyzine pamoate	0069-5410	D&C RED NO. 33
Pfizer Laboratories Div Pfizer Inc	VISTARIL	hydroxyzine pamoate	0069-5410	D&C YELLOW NO. 10
Pfizer Laboratories Div Pfizer Inc	VISTARIL	hydroxyzine pamoate	0069-5410	FD&C GREEN NO. 3
Pfizer Laboratories Div Pfizer Inc	VISTARIL	hydroxyzine pamoate	0069-5410	FD&C YELLOW NO. 6
Pfizer Laboratories Div Pfizer Inc	VISTARIL	hydroxyzine pamoate	0069-5410	MAGNESIUM STEARATE
Pfizer Laboratories Div Pfizer Inc	VISTARIL	hydroxyzine pamoate	0069-5410	SODIUM LAURYL SULFATE

Vistaril Excipient Strategy and Commercial Opportunities for Hydroxyzine Pamoate

Last updated: September 5, 2026

Vistaril is the branded formulation of hydroxyzine pamoate, an older antihistamine and anxiolytic marketed in oral capsules and injectable form. Its commercial opportunity is driven by formulation differentiation rather than molecule-level exclusivity. The strongest opportunities are dye-free and lactose-free capsules, pediatric and geriatric liquid products, orally disintegrating tablets, and differentiated products that address hydroxyzine’s bitter taste, sedation, and dosing flexibility.

Hydroxyzine pamoate has generic competition, no meaningful biologic exclusivity issue, and limited current patent leverage. A sponsor entering the market should prioritize regulatory simplicity, excipient tolerability, manufacturing economics, and patient-use advantages.

What is Vistaril and which dosage forms contain hydroxyzine pamoate?

Vistaril contains hydroxyzine pamoate, the pamoate salt of hydroxyzine. The product has historically been marketed in oral capsules and intramuscular injection. Hydroxyzine is also available as hydroxyzine hydrochloride in tablets, capsules, and oral solutions.

Attribute	Vistaril
Active ingredient	Hydroxyzine pamoate
Therapeutic class	Antihistamine; anxiolytic; sedative
Principal uses	Anxiety, pruritus, preoperative or postoperative sedation
Oral dosage forms	Capsules; generic oral products
Parenteral dosage form	Intramuscular injection
Regulatory pathway for generic capsules	ANDA, subject to reference-product requirements
New differentiated dosage form	Potentially 505(b)(2), depending on formulation and reliance on existing findings
Biosimilar exposure	None
Core commercial constraint	Mature generic competition and low molecule-level differentiation

The pamoate salt is poorly water-soluble relative to hydroxyzine hydrochloride. That property can support solid oral dosage forms but creates formulation challenges for liquid products, taste masking, suspension uniformity, and dose-volume control.

Vistaril labeling identifies capsule strengths of 25 mg, 50 mg, and 100 mg hydroxyzine pamoate. The injectable product contains hydroxyzine hydrochloride rather than hydroxyzine pamoate, so the two products should not be treated as interchangeable formulation platforms.[1]

What excipients are used in Vistaril capsules?

Vistaril capsule excipients have historically included gelatin, lactose, starch, magnesium stearate, sodium lauryl sulfate, talc, titanium dioxide, and colorants. Exact excipient composition can differ by manufacturer, strength, market, and label revision.

A representative Vistaril capsule excipient profile includes:

Excipient category	Representative function	Commercial implication
Lactose	Diluent and capsule-fill bulking agent	Limits use in lactose-avoidant patients; requires milk-allergen communication controls
Starch	Diluent, disintegrant, or binder	Low cost and familiar manufacturing profile
Magnesium stearate	Lubricant	Excess use can affect dissolution and powder flow
Sodium lauryl sulfate	Wetting agent or surfactant	May improve dispersion but can create tolerability and labeling concerns
Talc	Glidant or processing aid	Useful for flow; requires controlled particulate specifications
Gelatin	Capsule shell	Excludes vegetarian and some religious-use segments
Titanium dioxide	Opacifier and whitening agent	Increasingly relevant to global regulatory and consumer acceptance policies
Synthetic colorants	Capsule identification	Creates an opportunity for dye-free products
Water	Capsule-shell component	Controlled through shell specifications and stability testing

The excipient profile should be confirmed against the target reference listed drug and current FDA labeling before an ANDA formulation is finalized. FDA’s Inactive Ingredient Database is useful for precedent, but it does not establish automatic approval for a new strength, route, or dosage form.[2]

What excipient strategy is most attractive for a Vistaril generic?

The highest-value strategy is a targeted “clean-label” capsule that preserves bioequivalence while removing excipients with the clearest commercial disadvantages.

Lactose-free and dye-free capsules

A lactose-free capsule can target patients with lactose intolerance, dietary restrictions, or intolerance to specific fillers. A dye-free capsule can address pediatric use, chronic pruritus treatment, and institutional formularies that prefer fewer colorants.

Potential replacement systems include:

• Microcrystalline cellulose
• Pregelatinized starch
• Mannitol
• Dibasic calcium phosphate
• Low-substituted hydroxypropyl cellulose
• Crospovidone or croscarmellose sodium
• Hypromellose capsule shells

Each replacement changes powder flow, compactability, dissolution, capsule fill weight, and moisture behavior. A lactose-free formulation should not be assumed to be therapeutically equivalent without comparative dissolution and bioequivalence work.

Vegetarian or hypromellose capsules

Replacing gelatin with hypromellose can open vegetarian, halal, kosher, and institutional channels. Hypromellose capsules also reduce animal-derived material concerns. The tradeoff is higher shell cost and potentially different moisture transfer during storage.

Hydroxypropyl starch capsules are another option, but the sponsor would need to assess shell brittleness, oxygen permeability, capsule-machine compatibility, and dissolution across pH conditions.

Reduced-surfactant formulation

Sodium lauryl sulfate can improve wetting of hydrophobic drug particles, but it may be viewed negatively by consumers and certain institutional buyers. A formulation using particle-size control, co-processing, or alternative surfactants could reduce or eliminate sodium lauryl sulfate.

The technical risk is dissolution failure. Hydroxyzine pamoate’s low aqueous solubility makes wetting and dispersion important. A reduced-surfactant strategy should use comparative dissolution, particle-size distribution, solid-state characterization, and fed-versus-fasted evaluation.

What liquid formulations are protected or commercially attractive?

Hydroxyzine pamoate oral liquids offer a meaningful differentiation opportunity because pediatric, geriatric, and swallowing-impaired patients may not tolerate capsules. The principal formulation challenge is the active ingredient’s poor aqueous solubility.

Three development approaches are available:

Liquid approach	Technical profile	Commercial position
Aqueous suspension	Uses suspended hydroxyzine pamoate particles	Familiar product format; requires sedimentation, redispersibility, and dose-uniformity control
Hydroxyzine hydrochloride solution	Uses a more soluble salt	May require a separate regulatory strategy and is not the same salt as Vistaril
Taste-masked suspension	Combines particle engineering with sweeteners and flavors	Strong pediatric opportunity but higher development and stability complexity

A hydroxyzine pamoate suspension would need controls for particle size, sedimentation rate, redispersibility, viscosity, microbial limits, preservative effectiveness, and dose withdrawal accuracy. The formulation should avoid excessive viscosity that impairs oral syringes or creates dose variability.

Taste masking is commercially important because hydroxyzine can produce a bitter or unpleasant sensory profile. Suitable tools include polymer coating, ion-exchange resins, lipid barriers, cyclodextrin complexes, and multiparticulate systems. Sweeteners and flavors alone may not adequately mask the active ingredient at clinically useful concentrations.

A preservative-free unit-dose suspension could target pediatric hospitals and specialty pharmacies, but packaging costs would rise. A multidose product with an oral syringe is more commercially scalable.

Can hydroxyzine pamoate be developed as an orally disintegrating tablet?

An orally disintegrating tablet, or ODT, is a viable differentiated dosage form if the sponsor controls taste and tablet robustness. Hydroxyzine pamoate’s dose range is suitable for a low-to-moderate-dose ODT platform, particularly at 25 mg.

Potential excipient systems include:

• Mannitol for mouthfeel and cooling sensation
• Crospovidone or croscarmellose sodium for rapid disintegration
• Microcrystalline cellulose for tablet structure
• Colloidal silicon dioxide for flow
• Magnesium stearate at controlled levels
• Sucralose, acesulfame potassium, or other sweeteners
• Flavor systems
• Taste-masking polymers or coated drug particles

A 100 mg ODT could be technically more difficult because of tablet mass, taste burden, and mechanical strength. A 25 mg product is the most commercially defensible starting strength for anxiety, pruritus, and preoperative use.

The ODT route could support a 505(b)(2) strategy if the proposed product differs materially from the reference product in dosage form or administration characteristics. The sponsor would need a regulatory bridge to existing hydroxyzine safety and efficacy findings, together with product-specific clinical or pharmacokinetic data where required.[3]

What patents protect Vistaril and hydroxyzine pamoate?

The original composition-of-matter protection for hydroxyzine is expired. Vistaril is a legacy product, and generic hydroxyzine pamoate products have been marketed for many years.

The current competitive position is therefore based on:

• FDA approval and product-specific regulatory data
• Manufacturing know-how
• Formulation performance
• Trademark rights
• Distribution and contracting
• Potentially narrow formulation or delivery patents for new products

No active composition-of-matter patent should be assumed to protect Vistaril. A new sponsor would need a current patent search covering hydroxyzine pamoate, hydroxyzine hydrochloride, liquid suspensions, ODTs, taste-masked particles, multiparticulates, and therapeutic combinations before committing to a protected product strategy.

What is the Orange Book status of Vistaril?

The FDA Orange Book identifies approved drug products and certain patent and exclusivity information. Legacy Vistaril listings and current generic availability should be reviewed by dosage form and strength. An Orange Book listing does not itself establish that the branded product has commercially active sales or that every historical listing remains relevant to a new formulation.[4]

For a standard hydroxyzine pamoate capsule, the practical expectation is generic competition rather than an unexpired Vistaril patent barrier. A differentiated liquid, ODT, or taste-masked product may have a separate patent estate if the formulation has novel and non-obvious technical features.

When does Vistaril lose exclusivity?

Vistaril has already lost practical market exclusivity. Hydroxyzine pamoate has been available through generic manufacturers, and the product does not have current small-molecule exclusivity comparable to a recently approved branded drug.

Exclusivity category	Vistaril status
New chemical entity exclusivity	Expired
Original composition patent	Expired
Pediatric exclusivity	No current commercial relevance
Orphan exclusivity	Not applicable
Biologic exclusivity	Not applicable
Generic competition	Established
New-product opportunity	Formulation, delivery, packaging, or service differentiation

The absence of molecule-level exclusivity lowers entry barriers but also limits pricing power. A sponsor should not invest in a conventional “me-too” capsule unless it has a cost advantage, a reliable supply position, or a payer and channel strategy.

Are there Paragraph IV challenges or Vistaril patent lawsuits?

Hydroxyzine pamoate is an old genericized product. Paragraph IV litigation is not the primary commercial issue for the conventional capsule market. Any current litigation assessment would need to focus on newly patented formulations, delivery systems, or method-of-use claims rather than the original Vistaril molecule.

A formulation sponsor should monitor:

• ANDA filings referencing a newly listed product
• Paragraph IV certifications against formulation patents
• Declaratory judgment actions
• Hatch-Waxman infringement litigation
• Patent-term adjustments and pediatric extensions
• Settlement agreements restricting launch timing or manufacturing sources

No biosimilar litigation applies because hydroxyzine is a small molecule. A generic applicant would generally face ANDA requirements, not the abbreviated pathway used for biologic products.

What FDA regulatory pathway applies to a new Vistaril formulation?

A standard capsule that is therapeutically equivalent to the reference product would generally pursue an ANDA. A materially different dosage form, route, or formulation may require a 505(b)(2) application.

Product concept	Likely pathway	Key development burden
Conventional hydroxyzine pamoate capsule	ANDA	Bioequivalence, CMC, stability, labeling
Lactose-free capsule	ANDA if equivalent and acceptable	Excipient justification and bioequivalence
Hydroxyzine pamoate suspension	Potentially 505(b)(2) or ANDA depending on reference and product history	Dose uniformity, stability, taste, clinical bridge
ODT	Often 505(b)(2) if no suitable reference dosage form	Disintegration, taste, pharmacokinetics, usability
Hydroxyzine hydrochloride solution	Separate product strategy	Salt, concentration, labeling, and clinical bridge
Injectable product	ANDA if matching reference product	Sterility, particulate control, container closure, injection-site data

FDA’s inactive-ingredient rules permit excipients used in approved products, but precedent does not remove the need to justify levels, route, dosage form, and patient population under the applicable regulatory pathway.[2,5]

Which excipient combinations create the strongest commercial opportunity?

The most attractive portfolio is a tiered product line rather than a single reformulation.

Product	Target patient or channel	Commercial rationale
Dye-free, lactose-free capsule	Retail pharmacy and chronic users	Low technical risk and broad patient relevance
Hypromellose capsule	Vegetarian, religious, and institutional segments	Clear excipient differentiation
25 mg ODT	Acute anxiety, pruritus, swallowing difficulty	Convenience and rapid administration
Pediatric suspension	Pediatrics and specialty pharmacy	Dose flexibility and caregiver usability
Preservative-free unit-dose suspension	Hospitals and outpatient clinics	Infection-control and packaging differentiation
High-concentration suspension	Adult and geriatric use	Lower dose volume and reduced administration burden

A sponsor should avoid unnecessary excipient complexity. Each additional flavor, preservative, polymer, or surfactant adds stability, supply, and regulatory work. The best first product is likely a capsule with a simplified excipient profile, followed by a low-dose ODT or taste-masked suspension.

How strong is the patent estate for a new hydroxyzine product?

The patent estate for legacy hydroxyzine is weak. The patent opportunity for a new delivery system can be moderate if the sponsor generates technical data showing an unexpected benefit.

Potentially protectable subject matter includes:

• Specific taste-masking coatings
• Defined particle-size distributions
• Stable hydroxyzine pamoate suspensions
• Preservative-free multidose systems
• ODT compositions with rapid disintegration and acceptable taste
• Multiparticulate capsules
• Combination products with novel release profiles
• Device-linked dosing systems

A broad claim covering “hydroxyzine with pharmaceutical excipients” would face substantial prior-art risk. Stronger claims would specify quantitative ranges, process steps, dissolution profiles, stability results, or sensory performance.

Trade-secret protection may be more valuable than patents for particle engineering, coating parameters, flavor systems, and manufacturing conditions. The commercial value of a patent depends on whether the formulation produces a defensible patient or payer benefit.

What licensing and acquisition opportunities exist?

Licensing opportunities are more likely to involve formulation technology than Vistaril rights. Relevant assets include:

• Taste-masking platforms for bitter drugs
• Spray-dried or fluid-bed-coated particles
• ODT manufacturing technology
• Pediatric suspension platforms
• Hypromellose capsule supply
• Low-shear suspension processing
• Oral syringe and unit-dose packaging systems

A license should be evaluated against hydroxyzine’s low selling price. Royalty-bearing technology is difficult to support unless it enables a premium product, reduces manufacturing cost, or provides regulatory exclusivity.

Acquiring a legacy brand would offer limited strategic value unless the transaction includes distribution contracts, institutional formulary access, or a differentiated formulation. The active ingredient itself is widely available.

What generic launch scenarios exist for Vistaril?

Low-cost conventional capsule

This scenario offers the fastest regulatory route but the weakest margin. Success depends on API sourcing, manufacturing scale, reliable supply, and pharmacy contracting.

Premium clean-label capsule

A lactose-free, dye-free, gelatin-free product could command modest channel value, especially in specialty pharmacy and institutional markets. The product would still face generic substitution pressure.

Pediatric liquid launch

A hydroxyzine pamoate suspension could capture a more defensible niche. The main risks are taste, sedimentation, microbial control, and dose accuracy.

ODT launch

An ODT could support brand differentiation and potentially a 505(b)(2) strategy. Commercial performance would depend on demonstrated convenience and tolerability rather than the active ingredient alone.

Authorized or co-branded generic

A branded-generic structure could use established retail distribution while avoiding the full cost of building a new clinical brand. The product would remain price sensitive.

What revenue exposure does Vistaril create?

Public revenue data for Vistaril as a standalone brand is limited because hydroxyzine is sold through multiple generic manufacturers and dosage forms. The relevant revenue pool is the aggregate hydroxyzine market, not historical Vistaril sales alone.

Commercial exposure is concentrated in:

• Low unit prices
• Multiple generic suppliers
• Retail pharmacy substitution
• Limited prescriber loyalty to the brand
• Low switching costs for standard capsules
• Potential supply volatility for older APIs
• Payer preference for the lowest-cost product

A differentiated formulation can improve margin, but the addressable market is constrained by hydroxyzine’s mature clinical profile and widespread generic availability. The highest-value segment is likely a formulation that solves a specific administration problem, particularly pediatric dosing, swallowing difficulty, or taste intolerance.

Key Takeaways

• Vistaril is hydroxyzine pamoate, an old small-molecule product with expired core exclusivity.
• Generic competition is established; conventional capsules offer limited pricing power.
• The most practical first opportunity is a lactose-free, dye-free, gelatin-free capsule.
• Pediatric suspension and 25 mg ODT products offer stronger differentiation but require greater formulation and regulatory investment.
• Hydroxyzine pamoate’s low aqueous solubility makes taste masking, suspension stability, and dose uniformity central technical issues.
• A standard capsule is generally an ANDA opportunity; a materially different ODT or liquid may require a 505(b)(2) strategy.
• Biosimilar risk is irrelevant because hydroxyzine is a small molecule.
• New patent value would come from narrowly defined formulation, particle-engineering, delivery, or manufacturing claims.
• Licensing is more attractive for enabling formulation technology than for legacy Vistaril brand rights.
• Commercial success depends on channel differentiation, manufacturing cost, and reliable supply rather than molecule-level exclusivity.

FAQs

Is hydroxyzine pamoate the same as hydroxyzine hydrochloride?

No. Both deliver hydroxyzine, but they are different salts with different physicochemical properties. Hydroxyzine pamoate is associated with Vistaril capsules, while hydroxyzine hydrochloride is used in other oral and injectable products.

Which excipient should be removed first from a Vistaril generic?

Lactose and colorants are the clearest commercial targets because lactose-free and dye-free positioning is easy to communicate. Gelatin is another target where vegetarian, religious, or institutional requirements are important.

Is a hydroxyzine pamoate oral solution technically feasible?

A true solution is difficult because hydroxyzine pamoate has limited water solubility. A suspension, taste-masked suspension, or alternative hydroxyzine salt product is generally more practical.

Can a hydroxyzine ODT receive new patent protection?

Yes, if the ODT has patentable technical features such as a defined taste-masking system, particle architecture, excipient ratio, disintegration profile, or stability advantage. Broad claims covering routine ODT excipients would face significant prior-art exposure.

Does Vistaril have biosimilar competition?

No. Vistaril contains a small-molecule active ingredient. Competition occurs through generic drug pathways, not biosimilar approval pathways.

References

1. Pfizer Laboratories. (n.d.). Vistaril (hydroxyzine pamoate) capsules and injection prescribing information. U.S. Food and Drug Administration labeling archive.

2. U.S. Food and Drug Administration. (n.d.). Inactive Ingredient Database. https://www.accessdata.fda.gov/scripts/cder/iig/index.cfm

3. U.S. Food and Drug Administration. (2022). Applications covered by section 505(b)(2). https://www.fda.gov/drugs/biologics-price-competition-and-innovation-act-bpci-act/applications-covered-section-505b2

4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: 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. (2016). Guidance for industry: Size of beads in drug products labeled for sprinkle. U.S. Department of Health and Human Services.