List of Excipients in Branded Drug PHENADOZ

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Generic Drugs Containing PHENADOZ

Company	Ingredient	NDC	Excipient
Actavis Pharma Inc	promethazine hydrochloride	0591-2985	ASCORBYL PALMITATE
Actavis Pharma Inc	promethazine hydrochloride	0591-2985	FAT, HARD
Actavis Pharma Inc	promethazine hydrochloride	0591-2985	GLYCERYL MONOSTEARATE
Actavis Pharma Inc	promethazine hydrochloride	0591-2985	SILICON DIOXIDE
Actavis Pharma Inc	promethazine hydrochloride	0591-2985	WHITE WAX

What are the Most Frequently-Used Excipients in PHENADOZ?

# Of NDCs	Excipient
3	ASCORBYL PALMITATE
3	FAT, HARD
3	GLYCERYL MONOSTEARATE
3	SILICON DIOXIDE
3	WHITE WAX

PHENADOZ Excipient Strategy and Commercial Opportunities

Last updated: October 14, 2026

PHENADOZ is a promethazine hydrochloride rectal suppository marketed in 12.5 mg, 25 mg, and 50 mg strengths. Its commercial value is tied less to active-ingredient exclusivity than to reliable suppository manufacture, controlled melting and drug release, supply continuity, and access to patients who cannot use oral or injectable promethazine. The publicly identified formulation uses a hydrogenated vegetable-oil suppository base. The main commercial opportunities are supply-chain differentiation, hospital and institutional contracts, private-label distribution, shortage mitigation, and improved formulations that address rectal tolerability, leakage, stability, and dose uniformity. [1]

What is PHENADOZ and how is it supplied?

PHENADOZ contains promethazine hydrochloride, a phenothiazine derivative used for allergy symptoms, nausea and vomiting, motion sickness, and sedation-related indications. The product is administered rectally as a suppository when oral administration is impractical or not tolerated. [1]

Attribute	PHENADOZ profile
Active ingredient	Promethazine hydrochloride
Dosage form	Rectal suppository
Marketed strengths	12.5 mg, 25 mg, 50 mg
Therapeutic class	Phenothiazine antihistamine and antiemetic
Primary delivery barrier	Rectal administration
Publicly identified base	Hydrogenated vegetable oil
Regulatory pathway	Generic or legacy prescription product, depending on listed product and applicant
Key safety issue	Serious respiratory depression risk in young children; boxed-warning restrictions apply to promethazine products
Commercial substitutes	Oral tablets, oral solutions, injectable promethazine, and alternative antiemetics

The dosage form has a narrower market than tablets or oral liquids, but it addresses a distinct clinical need. The relevant customers include hospitals, long-term-care facilities, emergency departments, hospice providers, institutional pharmacies, and patients with vomiting, dysphagia, reduced consciousness, or poor gastrointestinal tolerance.

What excipients are used in PHENADOZ suppositories?

The publicly available product information identifies a hydrogenated vegetable-oil base. The public label does not provide the full quantitative composition, grade, particle-size distribution, manufacturing temperature profile, or supplier identity. [1]

Why a hydrogenated vegetable-oil base is commercially relevant

A hydrogenated vegetable-oil base can provide:

• A solid dosage form at room temperature.
• Melting or softening near physiological temperature.
• Compatibility with a lipophilic or partially lipophilic active ingredient.
• Established suppository manufacturing processes.
• A relatively familiar excipient profile for regulators and institutional buyers.

The base determines more than physical shape. It affects drug dispersion, sedimentation during filling, melting time, leakage after administration, storage stability, microbial risk, and dose uniformity.

Promethazine hydrochloride is a salt and has meaningful water solubility. A lipid suppository base may therefore require careful control of drug distribution and wetting. The formulation strategy must prevent sedimentation during filling and avoid localized concentration gradients between the tip, middle, and end of the suppository.

Likely critical formulation variables

Formulation variable	Commercial impact
Base melting range	Controls handling, patient comfort, and release
Drug particle size	Influences suspension uniformity and dissolution
Viscosity during filling	Determines sedimentation and weight variation
Mixing time and temperature	Affects dispersion and polymorphic or thermal behavior
Mold geometry	Affects dose volume, insertion, and packaging
Cooling rate	Influences crystal structure and mechanical strength
Packaging barrier	Controls softening, oxidation, and moisture exposure
Container closure	Affects shelf life and product presentation

An excipient supplier or contract manufacturer can create value by qualifying multiple pharmaceutical-grade hydrogenated vegetable-oil bases with equivalent performance. This would reduce dependence on a single supplier and improve continuity during raw-material disruptions.

What excipient strategy best supports PHENADOZ commercialization?

The strongest strategy is a platform approach built around a validated suppository base rather than a simple substitution of one excipient for another.

1. Maintain a conventional base for regulatory efficiency

A hydrogenated vegetable-oil base is likely the lowest-risk starting point because it aligns with the existing product concept. The development program should prioritize:

• Comparable melting behavior.
• Comparable disintegration and dissolution.
• Equivalent assay and content uniformity.
• Equivalent stability under long-term and accelerated conditions.
• Comparable mechanical strength.
• No increase in rectal irritation.

A close formulation match may support a more efficient generic or line-extension strategy, depending on the regulatory pathway and reference product.

2. Develop a high-performance base as a second platform

A second formulation platform could use a modern hard-fat or semi-synthetic triglyceride system. Possible goals include:

• Reduced leakage.
• Higher resistance to softening during distribution.
• More reproducible release.
• Better performance in warm climates.
• Improved compatibility with automated filling.
• Lower batch-to-batch variability.

This approach could support a differentiated product, but the company would need to establish that changes in excipients do not create clinically meaningful differences in local tolerability, absorption, or pharmacokinetics.

3. Improve suspension stability

The highest technical risk is often not the identity of the base but uniformity of promethazine hydrochloride through the fill mass. Candidate controls include:

• Controlled drug particle-size distribution.
• Optimized wetting.
• Increased bulk viscosity during filling.
• Agitation that prevents settling without introducing air.
• Narrow temperature control.
• In-process sampling at multiple fill locations.
• Validated hold-time limits before filling.

Surfactants and suspending agents may improve dispersion, but they also increase regulatory complexity and can affect irritation, release, and stability. Any new excipient should have a strong pharmaceutical history and a clear justification under FDA inactive-ingredient expectations. [2]

What formulations are protected by PHENADOZ patents?

PHENADOZ has limited apparent patent-based differentiation compared with newer drug-delivery products. The core product is an established promethazine hydrochloride suppository, and the commercial moat is more likely to arise from manufacturing know-how, regulatory approval, supply reliability, and customer contracts than from an extensive composition-of-matter estate.

Potentially protectable improvements include:

Candidate asset	Patent potential
Novel low-leakage suppository base	Moderate if performance is unexpected
Improved dose-uniformity process	Moderate, particularly as a manufacturing method
Heat-stable formulation	Moderate if supported by comparative data
Reduced-irritation formulation	Moderate to high if clinically supported
New packaging system	Moderate
Pediatric or geriatric dosing configuration	Moderate
Novel rectal delivery applicator	Moderate to high
New therapeutic use	Limited by prior art and existing promethazine uses

A patent strategy should focus on measurable performance advantages rather than claiming a generic hydrogenated vegetable-oil base. Broad claims covering a conventional base, promethazine, and a suppository are vulnerable to prior-art challenges.

When does PHENADOZ lose exclusivity?

PHENADOZ is not primarily an exclusivity-driven product. Promethazine hydrochloride is an old active ingredient, and the relevant market has long included multiple dosage forms and manufacturers. The principal risks are therefore generic competition, product discontinuation, manufacturing interruptions, and declining institutional demand.

FDA regulatory exclusivity

The product should not be analyzed like a recently approved new chemical entity. Any remaining regulatory protection would depend on the specific NDA or ANDA, approval history, and listed product status. FDA approval does not itself establish a current market monopoly for an old generic dosage form.

Orange Book status

The Orange Book analysis must distinguish:

• The reference listed drug.
• Approved abbreviated new drug applications.
• Any active patent listings.
• Pediatric exclusivity.
• NDA exclusivity.
• Discontinued or “not therapeutically equivalent” listings.

For an established promethazine suppository, the commercial expectation is a low-exclusivity market unless a specific product has an active formulation or method-of-use listing. FDA’s Orange Book remains the controlling source for current patent and exclusivity entries. [3]

Are there Paragraph IV challenges to PHENADOZ?

Paragraph IV exposure is possible only where a company files an ANDA with a certification that an Orange Book-listed patent is invalid, unenforceable, or will not be infringed. The practical significance depends on whether active patents are listed against the relevant reference product.

For an old promethazine suppository, the more likely competitive pathway is ordinary generic entry or an ANDA based on an established reference product rather than a high-value Paragraph IV campaign. A meaningful Paragraph IV dispute would require a listed patent covering one of the following:

• The suppository composition.
• A specific excipient ratio.
• A release profile.
• A manufacturing process.
• A method of treating a listed indication.

No commercial assessment should assume a Paragraph IV barrier without a current Orange Book listing and corresponding patent number. [3]

What patent litigation affects PHENADOZ?

The principal litigation risks are formulation and manufacturing disputes rather than active-ingredient patent disputes.

Likely litigation theories

A patent holder could assert:

1. Composition claims covering a specific hard-fat or lipid base.
2. Process claims covering suspension, cooling, or filling conditions.
3. Packaging claims covering heat protection or unit-dose containment.
4. Method-of-use claims involving rectal administration for a defined patient population.
5. Trade-secret claims concerning scale-up, temperature control, or supplier specifications.

Generic applicants could challenge such patents through Paragraph IV litigation or post-grant proceedings. Commercial risk rises when the patent claims include narrow but difficult-to-design-around process parameters that are essential for dose uniformity.

Publicly available regulatory information does not establish a significant, active litigation campaign centered on PHENADOZ itself. The more material risk is a future dispute involving a reformulated or line-extended product with new formulation claims.

What commercial opportunities exist for PHENADOZ excipients?

Supply-chain substitution

The clearest opportunity is qualification of alternative base suppliers. A supplier that can provide pharmaceutical-grade hydrogenated vegetable oil with consistent melting range, low peroxide value, reliable documentation, and global availability can compete on continuity rather than price alone.

Private-label and contract manufacturing

A manufacturer could offer:

• 12.5 mg, 25 mg, and 50 mg presentations.
• Unit-dose packaging.
• Institutional cartons.
• Hospital and long-term-care configurations.
• Private-label products for regional distributors.
• Contract filling and packaging for authorized applicants.

The market is well suited to a small number of qualified manufacturers because suppository production is more specialized than tablet compression.

Shortage-response products

Supply interruptions create an opportunity for an approved alternative with:

• A validated base.
• Existing promethazine API supply.
• Rapid packaging conversion.
• Multiple qualified raw-material vendors.
• Established stability data.
• Institutional purchasing relationships.

FDA’s drug-shortage framework and product listing data should be monitored to identify periods when supply reliability becomes a purchasing priority. [4]

Improved patient-use products

Commercial differentiation could come from:

• Less leakage after insertion.
• Faster softening without excessive melt.
• Reduced rectal irritation.
• Better unit-dose wrapping.
• Clearer strength identification.
• Packaging that improves use by caregivers.
• A smaller suppository volume at equivalent strength.

These improvements are more likely to support market access and customer retention than a minor excipient change with no visible patient benefit.

How does PHENADOZ compare with other promethazine dosage forms?

Product type	Main advantage	Main limitation	Excipient opportunity
Rectal suppository	Useful when oral dosing is impractical	Administration burden and leakage	Base performance, comfort, packaging
Oral tablet	Low manufacturing cost and familiar use	Poor option during vomiting or dysphagia	Disintegration and swallowability
Oral solution	Flexible dosing	Stability, taste, and handling	Solubilization and preservative system
Injection	Rapid delivery in clinical settings	Administration risk and clinical restrictions	Container, preservative, and compatibility
Alternative antiemetic	May offer newer safety or convenience profile	Different clinical and formulary positioning	Delivery-system differentiation

PHENADOZ is unlikely to win on broad outpatient convenience. Its value is concentrated in settings where rectal delivery solves a practical clinical problem.

What generic launch risks exist?

A new entrant faces five principal risks:

1. Demonstrating comparable quality for a dosage form with limited public formulation detail.
2. Maintaining content uniformity during commercial-scale filling.
3. Controlling heat exposure during shipping and storage.
4. Establishing reliable API and base supply.
5. Building demand in a market with modest volume and price pressure.

A generic launch is more attractive when the entrant has existing suppository capacity, institutional distribution, and a differentiated packaging or supply proposition. It is less attractive for a company that must build dedicated equipment for a single low-volume product.

How strong is the PHENADOZ patent estate?

The patent estate appears commercially weak relative to modern specialty pharmaceuticals because the active ingredient and dosage form are longstanding. A conventional formulation likely has limited defensibility. The strongest future assets would be narrow patents supported by comparative data showing:

• Superior dose uniformity.
• Better stability under elevated temperature.
• Reduced leakage.
• Lower irritation.
• Improved release consistency.
• A manufacturing process that materially reduces rejection rates.

Trade secrets may provide greater practical protection than patents. Process controls, supplier specifications, mold design, cooling profiles, and validated hold times can be difficult for competitors to replicate even when the final ingredient list is public.

What licensing deals could support PHENADOZ growth?

Potential deal structures include:

• An excipient supplier licensing a validated suppository-base platform.
• A contract manufacturer licensing finished-product technology to a regional marketing company.
• A private-label arrangement with a hospital distributor.
• A co-development agreement for a low-leakage or heat-stable formulation.
• A supply agreement with dual-source API and base commitments.
• A royalty-bearing license for a novel applicator or packaging system.

The strongest licensing asset would combine a regulatory-ready formulation, process validation, stability data, and manufacturing capacity. An excipient alone is unlikely to command substantial royalties unless it delivers a clear performance advantage.

Key Takeaways

• PHENADOZ is a promethazine hydrochloride rectal suppository marketed in 12.5 mg, 25 mg, and 50 mg strengths.
• The publicly identified base is hydrogenated vegetable oil.
• The main technical challenge is uniform dispersion of promethazine hydrochloride through the suppository mass.
• The product has limited apparent active-ingredient exclusivity and is more exposed to generic competition than patent litigation.
• The strongest commercial opportunities are supply continuity, private-label manufacturing, institutional distribution, and improved leakage or heat stability.
• A patent program should target measurable formulation and manufacturing improvements, not a conventional suppository composition.
• Trade secrets and validated process controls may offer more practical protection than broad composition claims.
• Orange Book listings, FDA approval status, and shortage data should determine the current regulatory and commercial risk assessment.

FAQs About PHENADOZ Excipient and Commercial Strategy

What is the primary excipient in PHENADOZ suppositories?

The publicly available product information identifies a hydrogenated vegetable-oil suppository base. The complete quantitative formula and supplier specifications are not generally disclosed in the product label.

Can a different suppository base be used for a PHENADOZ generic?

Yes, but the applicant must establish pharmaceutical equivalence or the applicable regulatory standard, including assay, content uniformity, stability, release, and safety performance. A different base can increase development and regulatory risk.

Is PHENADOZ suitable for a 505(b)(2) reformulation?

A reformulated product could potentially use a 505(b)(2) pathway if it relies on FDA findings for an approved product while introducing a clinically meaningful change. The suitability depends on the proposed formulation, dosage form, claims, and supporting studies. [5]

What is the best patent angle for a new PHENADOZ formulation?

The strongest patent angle is a demonstrated improvement in leakage, thermal stability, rectal tolerability, release consistency, or manufacturing yield. Conventional promethazine-in-lipid suppository claims are likely to face prior-art pressure.

Which customers are most likely to buy a differentiated PHENADOZ product?

Hospitals, long-term-care pharmacies, hospice providers, emergency departments, institutional wholesalers, and regional generic distributors are the most plausible customers. Their purchasing decisions are likely to prioritize supply reliability, unit-dose packaging, and consistent product performance.

References

1. U.S. Food and Drug Administration. (n.d.). PHENADOZ (promethazine hydrochloride) suppository prescribing information. DailyMed.

2. U.S. Food and Drug Administration. (2021). Inactive ingredient database. https://www.accessdata.fda.gov/scripts/cder/iig/index.cfm

3. U.S. Food and Drug Administration. (2024). 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

4. U.S. Food and Drug Administration. (n.d.). Drug shortages. https://www.fda.gov/drugs/drug-safety-and-availability/drug-shortages

5. U.S. Food and Drug Administration. (2022). Applications covered by section 505(b)(2). https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/applications-covered-section-505b2