List of Excipients in Branded Drug PERPHENAZINE AND AMITRIPTYLINE HYDROCHLORIDE

Generic Drugs Containing PERPHENAZINE AND AMITRIPTYLINE HYDROCHLORIDE

Company	Ingredient	NDC	Excipient
Mylan Pharmaceuticals Inc	perphenazine and amitriptyline hydrochloride	0378-0330	CALCIUM SULFATE
Mylan Pharmaceuticals Inc	perphenazine and amitriptyline hydrochloride	0378-0330	CELLULOSE, MICROCRYSTALLINE
Mylan Pharmaceuticals Inc	perphenazine and amitriptyline hydrochloride	0378-0330	CROSCARMELLOSE SODIUM
Mylan Pharmaceuticals Inc	perphenazine and amitriptyline hydrochloride	0378-0330	HYDROXYPROPYL CELLULOSE

What are the Most Frequently-Used Excipients in PERPHENAZINE AND AMITRIPTYLINE HYDROCHLORIDE?

# Of NDCs	Excipient
1	CALCIUM SULFATE
1	CELLULOSE, MICROCRYSTALLINE
1	CROSCARMELLOSE SODIUM
1	HYDROXYPROPYL CELLULOSE

Perphenazine and Amitriptyline Hydrochloride: Excipient Strategy, Regulatory Status, and Commercial Opportunities

Last updated: August 23, 2026

Perphenazine and amitriptyline hydrochloride is an established fixed-dose combination of a phenothiazine antipsychotic and a tricyclic antidepressant. Its commercial opportunity is primarily a differentiated generic, reformulation, or niche-market opportunity rather than a new-molecule patent opportunity. The strongest product strategy is a low-cost, stable oral tablet with improved swallowability, reliable dose uniformity, and a defensible supply chain for controlled, quality-sensitive excipients.

What is the perphenazine and amitriptyline hydrochloride combination?

Perphenazine and amitriptyline hydrochloride combines:

Component	Drug class	Primary pharmaceutical role
Perphenazine	Phenothiazine antipsychotic	Antipsychotic and antiemetic activity
Amitriptyline hydrochloride	Tricyclic antidepressant	Antidepressant activity and central nervous system effects

The historical branded product was Triavil. U.S. labeling described the combination for depressive symptoms associated with anxiety, agitation, or tension, and for depressive symptoms occurring with schizophrenia or other psychotic disorders. The product was supplied as oral tablets in multiple strength combinations, including combinations based on 2 mg or 4 mg of perphenazine and 10 mg or 25 mg of amitriptyline hydrochloride.[1]

The combination has limited modern treatment-line use because both ingredients carry substantial central nervous system and anticholinergic risks. Its commercial value therefore depends on manufacturing efficiency, institutional demand, continuity of supply, and product differentiation rather than broad first-line prescribing.

What strengths and dosage forms are commercially relevant?

The historical dosage form is an immediate-release tablet. The key commercial strengths are:

Perphenazine	Amitriptyline hydrochloride	Commercial rationale
2 mg	10 mg	Lowest-strength option; potentially useful for cautious titration
2 mg	25 mg	Higher antidepressant component with lower antipsychotic exposure
4 mg	10 mg	Higher antipsychotic component with lower antidepressant exposure
4 mg	25 mg	Highest combined active load; most demanding for content uniformity and tolerability

The strength matrix creates a formulation challenge. The active ingredients are present in relatively small quantities, particularly perphenazine. Low-dose content uniformity, segregation control, and blend homogeneity are therefore more important than tablet mass reduction.

A standard immediate-release tablet is the most practical product for an abbreviated generic strategy. Modified-release, orally disintegrating, liquid, or multiparticulate products could create commercial differentiation, but each would increase development, analytical, stability, and regulatory burden.

What excipient strategy is appropriate for this combination?

A robust excipient strategy should prioritize dose uniformity, chemical stability, manufacturability, and patient acceptability.

Recommended excipient functions

Formulation function	Suitable excipient classes	Development objective
Diluent	Microcrystalline cellulose, lactose, dibasic calcium phosphate, mannitol	Achieve tablet mass and improve blend handling
Binder	Povidone, copovidone, pregelatinized starch, hydroxypropyl cellulose	Improve granule and tablet strength
Disintegrant	Croscarmellose sodium, crospovidone, sodium starch glycolate	Support rapid immediate-release breakup
Lubricant	Magnesium stearate, sodium stearyl fumarate	Control ejection force without slowing dissolution
Glidant	Colloidal silicon dioxide	Improve powder flow and reduce fill-weight variation
Film former	Hypromellose, polyvinyl alcohol	Improve appearance, handling, and light protection
Opacifier or pigment	Titanium dioxide or permitted colorants	Control appearance and product identification

The final composition must be established through compatibility, dissolution, stability, and process studies. A platform based on microcrystalline cellulose, a superdisintegrant, low-level colloidal silicon dioxide, and magnesium stearate is technically conventional and potentially cost-efficient. Direct compression may be feasible, but wet granulation can offer better control when the low-dose perphenazine fraction produces segregation or poor flow.

How should the formulation address low-dose perphenazine?

Perphenazine is the critical low-dose component in the combination. The principal risks are:

• Blend segregation during transfer or compression.
• Poor assay reproducibility across tablets.
• Content uniformity failures at the 2 mg strength.
• Interaction between particle-size distributions of the two active ingredients.
• Over-lubrication that slows disintegration and dissolution.

A formulation developer should characterize active-ingredient particle size, density, morphology, electrostatic behavior, and moisture sensitivity. Geometric dilution, ordered mixing, co-processing, or wet granulation can reduce segregation risk. A premix or granulated concentrate containing perphenazine may be preferable to direct addition of a small quantity of raw active.

The process should include blend-uniformity sampling at locations that represent hopper, transfer, and compression conditions. Content uniformity should be evaluated separately from assay because a satisfactory batch average does not establish individual-unit consistency.

Is a protective coating commercially useful?

Yes. A film coat can provide four practical benefits:

1. Better tablet identification across four strength combinations.
2. Reduced dusting and improved handling.
3. Improved patient acceptability.
4. Partial protection from light and environmental exposure.

Color-coded strengths can reduce medication-selection errors, but colorants introduce regulatory and supply-chain considerations. A simple white or light-colored film coat may provide the lowest-cost approach. An opaque coating may be valuable if stability studies show light sensitivity or if the tablet appearance is otherwise difficult to distinguish.

A coating should not be used to conceal poor core-tablet performance. Dissolution testing should compare coated and uncoated units across relevant pH conditions.

What excipients could create product differentiation?

The opportunity for excipient differentiation is limited but real.

Taste-masking and swallowability

Amitriptyline hydrochloride and perphenazine can create an unpleasant oral experience if the tablet is chewed or fragments in the mouth. A smooth, low-friction film coat can improve swallowability. An orally disintegrating tablet would require a separate development program and would need careful control of exposure to bitter active ingredients.

Low-allergen and clean-label positioning

A manufacturer could develop a formulation that excludes:

• Lactose, for customers seeking lactose-free products.
• Gluten-containing excipients.
• Artificial colorants.
• Animal-derived materials.
• Propylene glycol or other excipients that complicate certain customer specifications.

These claims would have to match the actual supplier documentation and finished-product controls. They may matter more in institutional purchasing or contract manufacturing than in conventional retail generic demand.

Supply-chain-resilient excipient selection

An excipient strategy should avoid dependence on a single supplier for critical materials. The best commercial formulation is not necessarily the one with the fewest excipients. It is the one that can be manufactured consistently using qualified alternative grades without triggering major regulatory changes.

Critical excipients should have:

• At least two qualified suppliers where feasible.
• Defined particle-size and moisture specifications.
• Stable global availability.
• Compendial compliance.
• Regulatory support files and change-notification commitments.

What is the FDA regulatory status of perphenazine and amitriptyline hydrochloride?

The combination is an old small-molecule oral product. Its regulatory pathway is generally an abbreviated new drug application, provided a reference product and applicable FDA standards are available.

FDA regulatory issues include:

• Identification of the correct reference listed drug.
• Demonstration of pharmaceutical equivalence.
• Strength-by-strength product development.
• Immediate-release dissolution performance.
• Content uniformity for the low-dose perphenazine component.
• Labeling consistency.
• Bioequivalence strategy for the fixed-dose combination.

The manufacturer should not assume that historical availability of the branded product automatically establishes a current, straightforward ANDA pathway. The applicable reference product, dosage-form status, and FDA listing position must be verified in current FDA databases before committing capital.

What is the Orange Book status of the combination?

The combination is unlikely to present a modern patent barrier comparable to protected small-molecule products launched in the last two decades. The active ingredients and historical combination are old products, and the commercial risk is more likely to involve regulatory reference-product status, manufacturing economics, and market size.

Orange Book analysis should examine:

• Current marketing status of the reference product.
• Whether the relevant strength remains listed.
• Whether any patents or exclusivity codes are shown.
• Whether a discontinued product remains eligible as a reference.
• Whether FDA has identified a petitioned or designated reference product.

For an old product, the absence of meaningful Orange Book patent protection does not eliminate development risk. A sponsor can still face difficulty if the reference product is discontinued, if the product is not currently marketed, or if the FDA pathway requires additional clinical or comparative evidence.

When does perphenazine and amitriptyline lose exclusivity?

The meaningful patent-exclusivity period ended decades ago for the underlying active ingredients and historical combination. The current commercial question is not when basic compound exclusivity expires. It is whether a sponsor can obtain approval and sell a legally compliant product at a cost that supports distribution.

Potential sources of residual exclusivity or market protection would be product-specific:

• A newly approved formulation.
• A new delivery system.
• A qualifying pediatric indication.
• A newly granted method-of-use patent.
• Regulatory exclusivity attached to a newly approved application.

No commercial plan should assume that a new excipient composition alone creates enforceable exclusivity. Ordinary excipient substitutions are generally difficult to protect unless they produce a measurable, non-obvious technical result and support a patentable formulation claim.

What formulation patents could protect a new product?

A meaningful formulation patent would need to claim more than a routine substitution of one diluent, binder, or lubricant for another. Stronger claim themes could include:

Low-dose content-uniformity architecture

Potential claims could focus on:

• A defined perphenazine particle-size distribution.
• A perphenazine premix or granulation method.
• Specified active-to-excipient ratios.
• A controlled blending sequence.
• A narrow content-uniformity profile.
• A dissolution profile tied to the formulation architecture.

Stability-enhancing composition

Potential claims could address:

• Protection against oxidation, hydrolysis, or photodegradation.
• A specific antioxidant or chelating system.
• A moisture-barrier film coat.
• Defined water activity or residual-moisture limits.
• Packaging and formulation combinations that improve shelf life.

Modified-release or abuse-deterrent systems

These would create a larger technical and regulatory opportunity but also greater development costs. A modified-release product would need to demonstrate that the pharmacokinetic profile is clinically appropriate for both components. Because perphenazine and amitriptyline have different pharmacology and tolerability concerns, a single release system may not optimize both drugs.

Combination-specific dissolution control

A patent could potentially cover a formulation that produces a defined release relationship between perphenazine and amitriptyline. Such claims would need strong comparative data, especially if the release profile is not predictable from conventional excipient selection.

What manufacturing and intellectual-property barriers exist?

The principal manufacturing barrier is not raw-material scarcity. It is low-dose combination control.

Technical barriers

• Perphenazine assay at low loading.
• Blend uniformity after scale-up.
• Tablet weight and hardness control.
• Lubricant sensitivity.
• Dissolution consistency across strengths.
• Stability of both actives in a common matrix.
• Cross-contamination controls in shared facilities.

Intellectual-property barriers

A generic immediate-release tablet is likely to have limited freedom-to-operate risk from active-ingredient patents. Risk increases if the product uses:

• A patented modified-release system.
• A proprietary coating technology.
• A branded excipient platform.
• A patented particle-engineering process.
• A licensed formulation or delivery system.

A sponsor should conduct a current worldwide patent search before adopting a differentiated delivery platform. The absence of historical compound patents does not establish freedom to operate for a new manufacturing process.

Which companies are challenging the reference product?

Publicly visible challenge activity for this old combination is likely to be limited. The product does not have the market profile of a high-revenue medicine that attracts multiple Paragraph IV filers.

A commercial review should distinguish among:

• ANDA applicants.
• Approved generic manufacturers.
• Contract manufacturers.
• Repackagers.
• Companies holding discontinued or inactive product listings.
• International suppliers that do not have U.S. approval.

Paragraph IV litigation is generally more likely for new formulation patents than for the historical combination itself. If a sponsor develops a patent-protected modified-release or orally disintegrating product, the litigation profile would change.

What generic launch risks exist?

The main launch scenarios are:

Scenario	Probability driver	Commercial result
Single approved generic	Small market, limited sponsor interest	Potentially attractive pricing but supply concentration
Several low-cost generics	Multiple manufacturers enter	Rapid price compression
Reference-product discontinuation	FDA pathway or market access complications	Delayed development or additional regulatory work
Niche institutional demand	Hospitals, psychiatric facilities, long-term care	Stable but limited volume
Differentiated reformulation	Better handling, strength identification, or delivery	Higher margin with greater development cost

The highest risk is underestimating the cost of regulatory and commercial maintenance. A product with low annual demand can still require stability batches, annual reporting, pharmacovigilance, quality investigations, and customer-service infrastructure.

What commercial opportunities exist?

U.S. generic opportunity

A U.S. generic could benefit from limited competition if the product has few active suppliers. The opportunity is strongest where a manufacturer can provide reliable availability across all historical strengths and avoid backorders.

The sponsor should assess:

• Current prescription volume.
• Wholesale acquisition price and average selling price.
• Medicaid and Medicare reimbursement.
• Pharmacy substitution behavior.
• Hospital and long-term-care purchasing.
• Existing shortage or discontinuation signals.
• Cost of active pharmaceutical ingredients and testing.

Institutional and long-term-care supply

The combination may have a more defensible niche in institutional settings than in broad retail prescribing. Buyers may value:

• Consistent supply.
• Unit-dose packaging.
• Clear strength differentiation.
• Low breakage and dusting.
• Simple inventory management.
• Contract pricing.

Unit-dose blister packaging could be commercially useful even if the underlying tablet is conventional.

International markets

The combination may have stronger commercial relevance in countries where older psychiatric medicines remain widely used and branded-generic substitution is common. Geographic opportunities depend on:

• Local registration requirements.
• National essential-medicine policies.
• Local pharmacovigilance rules.
• Reference-product availability.
• Pricing controls.
• Import restrictions.
• Local manufacturing requirements.

A global program should not assume that U.S. labeling, excipient permissions, or stability data transfer directly to every jurisdiction.

Licensing and contract manufacturing

The most practical licensing structures would involve:

• A finished-dose manufacturer licensing a ready-to-file formulation.
• A regional distributor acquiring commercialization rights.
• An API supplier providing dual-source security.
• A contract development and manufacturing organization supplying tablets and packaging.
• A specialty generic company acquiring rights to a differentiated dosage form.

Because the base product is old, a transaction based solely on historical compound rights is unlikely to command substantial value. Value is more likely to attach to regulatory readiness, manufacturing capacity, market access, or a protected formulation.

How strong is the patent estate?

The underlying patent estate is weak from a modern commercial-protection perspective because the active ingredients and historical fixed-dose product are old. The potentially protectable assets are formulation-specific and process-specific.

Asset	Likely protection strength	Commercial relevance
Perphenazine compound	Very low	Historical product only
Amitriptyline compound	Very low	Historical product only
Historical fixed-dose combination	Low	Supports generic product history, not strong exclusivity
Conventional immediate-release tablet	Low	Difficult to patent broadly
Low-dose uniformity process	Moderate if technically demonstrated	May support manufacturing differentiation
Stability-enhancing formulation	Moderate if unexpected results exist	Potential lifecycle management
Modified-release dosage form	Moderate to high if clinically differentiated	Higher margin, higher regulatory burden
Packaging and unit-dose system	Low to moderate	Commercial rather than core patent value

Patent strength depends on claim scope, prior art, enablement, written description, and evidence of unexpected performance. An excipient list without a demonstrated technical effect is unlikely to create a durable blocking position.

Is there biosimilar risk?

No. Perphenazine and amitriptyline hydrochloride are synthetic small molecules, not biologics. Biosimilar competition and the Biologics Price Competition and Innovation Act pathway are not relevant.

Competition would arise through generic ANDAs, local copies, branded generics, and reformulated products.

What patent litigation and settlement activity affects the product?

There is no widely recognized modern patent-litigation profile comparable to major protected medicines. For the historical immediate-release combination, litigation risk is likely to be low.

Risk would rise if a sponsor introduces:

• A new release profile.
• A patent-protected manufacturing process.
• A proprietary excipient system.
• A new indication.
• A delivery platform with separate patent ownership.

Any Paragraph IV settlement would need to be evaluated against the specific patent claims, first-filer status, 180-day exclusivity consequences, and whether the settlement restricts supply or commercialization. Historical combination status alone does not create a settlement opportunity.

How does this combination compare with competing treatment products?

Product category	Advantages over the combination	Disadvantages relative to the combination
Separate perphenazine and amitriptyline tablets	Flexible dose adjustment	More tablets and greater dispensing complexity
Modern atypical antipsychotic plus antidepressant	Current prescribing familiarity and broader guideline use	Higher acquisition cost and different safety profiles
Single-agent antidepressants	Simpler pharmacology and lower antipsychotic exposure	May not address psychotic or severe agitation symptoms
Other fixed-dose psychiatric combinations	Potentially stronger market acceptance	May have competing patent or regulatory barriers
Historical branded-generic combinations	Established product identity	Limited clinical differentiation

The fixed-dose combination’s main advantage is convenience and access to a low-cost older regimen. Its main disadvantage is reduced dose flexibility and the safety burden of two centrally acting ingredients.

What is the revenue exposure?

Revenue exposure is difficult to estimate without current prescription, pricing, payer, and competitor data. The product should be modeled as a low-volume or niche generic unless market evidence shows active institutional demand.

A commercial model should include:

• Unit volume by strength.
• Net price after wholesaler and payer discounts.
• Cost of goods by strength.
• API and excipient cost.
• Batch-size efficiency.
• Packaging and serialization cost.
• Regulatory maintenance expense.
• Expected competitor count.
• Inventory carrying cost.
• Returns and expiry exposure.

The 2 mg/10 mg and 2 mg/25 mg strengths may require more careful manufacturing economics because low active loading increases testing and process-control requirements without necessarily producing higher revenue.

Key Takeaways

• Perphenazine and amitriptyline hydrochloride is an old fixed-dose oral combination with limited modern patent protection.
• The primary opportunity is a reliable generic, institutional product, or differentiated reformulation.
• Low-dose perphenazine creates the central formulation challenge.
• Direct compression may be economical, but granulation or premixing may provide better content-uniformity control.
• Film coating can improve strength identification, handling, and patient acceptability.
• Excipient differentiation is commercially useful only when it produces measurable stability, dissolution, manufacturing, or usability benefits.
• There is no biosimilar risk because both active ingredients are synthetic small molecules.
• The most important commercial risks are reference-product status, limited market size, price compression, and manufacturing scale-up.
• A modified-release or stability-enhanced formulation could create stronger intellectual-property value, but it would require substantially greater development investment.
• Patent value is more likely to reside in a formulation or process than in the historical active ingredients or fixed-dose combination.

FAQs

Can perphenazine and amitriptyline hydrochloride be developed as an orally disintegrating tablet?

Yes, but the product would require taste-masking, mechanical-strength, moisture, dissolution, and bioequivalence development. The opportunity is technically feasible but likely too costly for a conventional low-volume generic unless the product has a clear market-access advantage.

Which excipient is most important for content uniformity?

No single excipient determines content uniformity. The critical variables are active particle-size distribution, premixing or granulation design, blend order, segregation control, and compression-process stability. Colloidal silicon dioxide, a suitable diluent, and a controlled binder system can support the process but cannot replace proper powder engineering.

Could a lactose-free formulation improve commercial positioning?

Yes. A lactose-free formulation could support institutional, pharmacy, and patient-specific procurement requirements. Its commercial value would depend on whether competing products already offer lactose-free compositions and whether the formulation retains acceptable flow, hardness, dissolution, and stability.

Would a new coating create patent protection?

Usually not by itself. A coating patent would require a technically meaningful composition or performance result, such as improved stability, controlled release, reduced degradation, or a reproducible manufacturing advantage that is not an obvious modification of known coating systems.

Is a fixed-dose combination preferable to separate perphenazine and amitriptyline products?

It may improve convenience and reduce pill burden, but it limits independent dose adjustment and can increase the clinical consequences of adverse effects from either active ingredient. The commercial case is strongest where prescribers already use the two drugs together and value simplified dispensing.

References

1. U.S. Food and Drug Administration. (n.d.). Triavil (perphenazine and amitriptyline hydrochloride) tablets: Prescribing information. FDA Drug Label Information.

2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA Orange Book.

3. U.S. Food and Drug Administration. (2013). Guidance for industry: ANDAs for certain highly purified synthetic peptides. FDA.

4. U.S. Food and Drug Administration. (2018). ANDAs for certain highly purified synthetic peptides: Questions and answers. FDA.

5. United States Pharmacopeial Convention. (2023). United States Pharmacopeia and National Formulary. USP Convention.