List of Excipients in Branded Drug TRIMIPRAMINE MALEATE

Generic Drugs Containing TRIMIPRAMINE MALEATE

Company	Ingredient	NDC	Excipient
Epic Pharma LLC	trimipramine maleate	42806-802	BUTYL ALCOHOL
Epic Pharma LLC	trimipramine maleate	42806-802	D&C YELLOW NO. 10
Epic Pharma LLC	trimipramine maleate	42806-802	FD&C BLUE NO. 1
Epic Pharma LLC	trimipramine maleate	42806-802	FD&C BLUE NO. 2
Epic Pharma LLC	trimipramine maleate	42806-802	FD&C RED NO. 40
Epic Pharma LLC	trimipramine maleate	42806-802	FERROSOFERRIC OXIDE

What are the Most Frequently-Used Excipients in TRIMIPRAMINE MALEATE?

# Of NDCs	Excipient
6	BUTYL ALCOHOL
5	D&C YELLOW NO. 10
6	FD&C BLUE NO. 1
6	FD&C BLUE NO. 2
5	FD&C RED NO. 40
6	FERROSOFERRIC OXIDE

Trimipramine Maleate Excipient Strategy and Commercial Opportunities

Last updated: August 20, 2026

Trimipramine maleate is an old tricyclic antidepressant with no meaningful remaining regulatory exclusivity in the United States. The commercial opportunity is therefore not patent protection for the active ingredient. It is product differentiation through reliable capsule supply, lower-cost manufacturing, improved swallowability, liquid or orally disintegrating dosage forms, pharmacy-channel products, and specialty formulations for patients who cannot use standard capsules.

The strongest near-term strategy is a robust immediate-release capsule platform using a simple, low-risk excipient system. Higher-value opportunities include a palatable oral liquid, sprinkle-compatible capsules, and potentially an orally disintegrating tablet. Any new dosage form would require a regulatory pathway and clinical or bioequivalence support proportionate to the formulation change.

What is trimipramine maleate and how is it marketed?

Trimipramine maleate is the maleate salt of trimipramine, a tertiary-amine tricyclic antidepressant. It is marketed for depressive illness, particularly where sedation is clinically useful. The drug has anticholinergic, antihistaminic and alpha-adrenergic pharmacology, creating a substantial excipient and dosage-form constraint: the formulation should not increase dosing complexity or worsen tolerability caused by the active ingredient.

Attribute	Trimipramine maleate
Therapeutic class	Tricyclic antidepressant
Drug substance	Trimipramine maleate
Common strengths	25 mg, 50 mg and 100 mg capsules
Legacy brand	Surmontil
Standard dosage form	Immediate-release oral capsule
FDA status	Approved legacy product with generic availability
Core commercial issue	Mature generic market with limited exclusivity
Main formulation risks	Content uniformity, capsule fill consistency, dissolution, moisture control and patient swallowability

The U.S. labeling for trimipramine maleate identifies capsule strengths and dosing instructions but does not create a current exclusivity barrier for competing manufacturers (National Library of Medicine, 2024).

What excipients are used in trimipramine maleate capsules?

Public product labels should be treated as the controlling source for each marketed product because excipient compositions vary by manufacturer. Legacy trimipramine capsule products generally use a conventional hard-gelatin capsule architecture with an active-containing powder blend and standard manufacturing aids.

Typical excipient categories include:

• Diluent to achieve capsule fill weight and improve blend uniformity.
• Binder or dry granulation aid to improve powder cohesion.
• Disintegrant to promote release after capsule shell rupture.
• Glidant to improve flow into capsule bodies.
• Lubricant to reduce tooling and capsule-filling friction.
• Capsule shell gelatin, titanium dioxide or permitted colorants.
• Printing ink for product identification.

A commercial formulation should avoid unnecessary excipient complexity. Trimipramine is an established immediate-release product, so a generic capsule normally benefits from a qualitative and quantitative excipient profile that supports rapid dissolution without introducing novel absorption behavior.

What is the preferred capsule excipient platform?

A practical platform would use a lactose-free or lactose-containing diluent depending on target market, a superdisintegrant, colloidal silicon dioxide and a low-level lubricant. Microcrystalline cellulose can improve powder structure, while mannitol can support a lower-density, more patient-friendly platform and may help future conversion to a sprinkle or orally disintegrating product.

The preferred choice depends on the physical properties of the drug substance:

Formulation objective	Excipient strategy
Low-cost generic capsule	Lactose or microcrystalline cellulose with a standard disintegrant and lubricant
Improved flow	Colloidal silicon dioxide, optimized particle size and controlled granulation
Lactose-free product	Microcrystalline cellulose, mannitol or dibasic calcium phosphate
Sprinkle-compatible capsule	Non-abrasive multiparticulate or granulated fill with controlled taste exposure
Moisture-sensitive product	Low-water-activity excipients, high-barrier packaging and desiccant
Liquid conversion platform	Solubilizer or suspending system, buffer, preservative and taste-masking system
ODT platform	Mannitol, crospovidone or another fast-disintegrating matrix with flavor and sweetener

The formulation developer should confirm compatibility between trimipramine maleate and aldehyde-containing excipients. Amine-containing drug substances can present chemical stability concerns with reducing sugars under certain conditions. Lactose should therefore be selected only after compatibility, impurity and stability testing. A lactose-free design can reduce this risk and support a differentiated label claim.

What excipient risks affect trimipramine maleate manufacturing?

The key technical risk is not novel delivery technology. It is process control.

Trimipramine maleate capsules require tight control of active distribution because the lower-strength capsule contains a relatively small amount of drug substance. Content uniformity can become a larger risk than assay. Direct compression or direct capsule filling may be viable only if particle size, density and flow are controlled. Wet granulation can improve uniformity but introduces water exposure and additional process steps.

The development program should address:

1. Drug-excipient compatibility under accelerated and long-term stability conditions.
2. Blend segregation during transfer and capsule filling.
3. Potency and content uniformity across commercial-scale batches.
4. Dissolution across the approved pH range.
5. Moisture uptake by the drug substance, blend and capsule shell.
6. Gelatin-shell brittleness or cross-linking under storage conditions.
7. Extractables and leachables from high-barrier blister or bottle packaging.
8. Nitrosamine and elemental impurity risk from raw materials and processing aids.

A dry-granulated blend may offer the best balance between uniformity and moisture control. If the active has adequate flow and compressibility, direct filling can lower cost. The final decision should follow development data rather than an assumption that the legacy product's manufacturing process remains optimal.

What formulations are protected by patents?

Trimipramine's basic compound, maleate salt and standard immediate-release capsule technology are legacy subject matter. U.S. composition patents and original product exclusivities expired many years ago. The current commercial value is therefore unlikely to depend on a surviving active-ingredient patent.

The FDA Orange Book is the primary U.S. source for listed patents and regulatory exclusivity associated with approved drug products. Publicly available Orange Book information does not indicate a current, commercially significant patent barrier for ordinary trimipramine maleate capsules (U.S. Food and Drug Administration, 2024a).

IP category	Commercial assessment
Trimipramine compound patent	Expired
Maleate salt protection	Legacy and expired
Conventional capsule formulation	No meaningful current barrier identified
Method-of-use patents	No significant current Orange Book barrier identified
Manufacturing process patents	Potentially relevant only if a new process is proprietary
Liquid, ODT or sprinkle formulation	Could support new patent filings if technically distinct
Regulatory exclusivity	No current meaningful exclusivity identified for the established capsule

A company developing a new dosage form could seek protection for a specific composition, taste-masking system, stability profile, multiparticulate architecture or manufacturing process. Patentability would depend on novelty, non-obviousness and claim scope. A generic capsule using ordinary excipients would have limited patent value.

When does trimipramine lose exclusivity?

Trimipramine lost the practical benefits of small-molecule market exclusivity decades ago. The remaining barriers are regulatory execution, supply-chain reliability, bioequivalence and commercial scale.

For a conventional capsule, an applicant would generally pursue an abbreviated new drug application using the reference product as the basis for demonstrating pharmaceutical equivalence and bioequivalence. A Paragraph IV certification would have limited relevance if no listed patent blocks the product. A Paragraph III certification could be used where an Orange Book patent has not expired but the applicant accepts delayed launch until expiration. For a mature product without relevant listed patents, the principal route is normally a standard non-infringement and non-applicable-patent strategy rather than a litigation-centered launch.

No significant current Paragraph IV litigation or settlement landscape is associated with standard trimipramine maleate capsules in the public record reviewed through June 2024. That reduces legal complexity but also means a manufacturer cannot rely on a litigation settlement to create market timing or commercial differentiation.

What is the FDA regulatory status of trimipramine maleate?

Trimipramine maleate is an FDA-approved prescription drug, and generic capsule products have been marketed under ANDA pathways. The reference product is associated with the legacy Surmontil product line. Product-specific approval, marketing and availability should be verified against current FDA databases and the manufacturer’s labeling.

A new capsule strength that matches an approved reference presentation may fit a conventional ANDA strategy. A materially different dosage form, such as an oral solution or ODT, may require a different regulatory approach, including a 505(b)(2) application where the applicant relies partly on published literature or an approved product but introduces a new formulation or route-related characteristic (U.S. Food and Drug Administration, 2023).

Could trimipramine support pediatric or geriatric formulations?

A liquid or dispersible dosage form could support patients with swallowing difficulty, institutional care needs or medication-administration constraints. It would not automatically create a pediatric indication. The label contains safety considerations typical of tricyclic antidepressants, including overdose risk, cardiovascular effects, anticholinergic effects and sedation. Any pediatric positioning would require regulatory and clinical support.

Geriatric use may be commercially relevant because capsule swallowing, polypharmacy and dose titration are common practical problems in older patients. An oral liquid with a calibrated dosing device could improve administration flexibility, but it would also increase risks from dosing errors, accidental exposure and taste-related nonadherence.

What commercial opportunities exist for trimipramine maleate?

The strongest opportunities are niche products rather than broad primary-care substitution.

1. Reliable generic capsule supply

Shortages, discontinuations and limited supplier participation can create value even for old drugs. A manufacturer with dependable active sourcing, redundant capsule capacity and disciplined inventory management could capture institutional and retail contracts.

The commercial model should emphasize:

• Multiple active-ingredient suppliers.
• Dual-source capsule shells and excipients.
• High-barrier packaging.
• Three approved strengths.
• Competitive unit economics.
• Stable wholesaler and group-purchasing contracts.

2. Lactose-free or low-excipient capsules

A clean-label, lactose-free capsule could target pharmacies, hospitals and patients with excipient sensitivities. This is a modest differentiation opportunity, not a premium pharmaceutical franchise. The label must accurately identify all inactive ingredients and avoid unsupported clinical claims.

3. Sprinkle-compatible capsules

A capsule that can be opened and administered with a compatible soft food could address swallowing difficulty. The formulation must maintain dose uniformity, limit powder loss and prevent unacceptable taste exposure. A conventional powder may not be suitable because trimipramine can produce a bitter or pharmacologically active taste. A coated multiparticulate approach would be more defensible technically but would raise development and manufacturing costs.

4. Oral liquid

An oral solution or suspension could support institutional, geriatric and swallowing-impaired use. The formulation would require:

• Taste masking.
• pH and solubility optimization.
• Preservative efficacy.
• Container-closure compatibility.
• A calibrated oral syringe.
• Stability after opening.
• Controls against dosing errors.

An oral solution may be difficult if the active has limited aqueous solubility. A suspension or cosolvent system may be more practical, but both create sedimentation, redispersibility and palatability requirements.

5. Orally disintegrating tablet

An ODT could offer a differentiated product for patients unable to swallow capsules. Mannitol-based systems, crospovidone, flavoring and compression aids are likely candidates. The main barriers are taste, dose loading, friability and rapid drug release. Because trimipramine is sedating and potentially toxic in overdose, unit-dose packaging and child-resistant secondary packaging would be important.

How strong is the patent estate for trimipramine maleate?

The patent estate for ordinary trimipramine maleate capsules is weak from an exclusivity perspective. Its value lies in freedom to operate and low entry barriers, not in proprietary control.

Factor	Assessment
Active-ingredient protection	Weak or expired
Standard capsule protection	Weak
Regulatory exclusivity	None of material current value identified
Formulation patent opportunity	Moderate for technically distinct liquid, ODT or multiparticulate products
Manufacturing know-how	Potentially meaningful for uniformity, yield and stability
Litigation exposure	Low for a standard capsule, subject to product-specific review
Generic entry risk	High
Pricing power	Low to moderate
Supply-based opportunity	Moderate where competitor participation is limited

A new patent filing should focus on a measurable technical advantage: improved stability, reduced impurity formation, improved taste masking, controlled moisture exposure, dose flexibility or a specific patient-use format. Broad claims covering “trimipramine plus conventional excipients” would face substantial validity risk.

How does trimipramine compare with competing antidepressants?

Trimipramine competes against other tricyclic antidepressants, selective serotonin reuptake inhibitors and sedating agents used in overlapping clinical settings. It has a smaller market and weaker commercial momentum than newer antidepressants.

Product category	Competitive advantage over trimipramine	Trimipramine opportunity
SSRIs	Larger prescribing base and generally simpler safety profile	Niche use where sedation or historical response matters
Other TCAs	More established use in pain or migraine for some products	Differentiation through formulation and supply
Sedating antidepressants	Familiar alternatives for sleep-associated symptoms	Liquid or low-dose administration
Compounded products	Custom strengths and dosage forms	FDA-approved, quality-controlled alternative
Generic capsules	Low price and broad availability	Contract supply and reliable distribution

The principal commercial risk is therapeutic substitution. A formulation improvement will not eliminate the need to compete with drugs that have broader indications, larger prescriber familiarity or lower monitoring burden.

What generic launch scenarios exist?

Low-investment capsule launch

The applicant files a conventional ANDA for one or more approved strengths, using a standard powder-fill capsule. This is the lowest-cost path but has the highest price competition and the weakest differentiation.

Moderate-investment differentiated capsule

The applicant launches a lactose-free, stability-optimized or supply-secured product. This may improve contracting prospects but is unlikely to command a large premium.

Higher-investment oral liquid

The product targets long-term-care facilities, specialty pharmacies and patients with swallowing difficulty. Development, packaging and regulatory costs increase, but the product may face less direct competition.

Specialty ODT or multiparticulate product

This offers the strongest potential differentiation and patent opportunity. It also carries the highest risk because of taste, dose loading, bioequivalence and commercial demand uncertainty.

What licensing deals and partnerships are relevant?

No major current licensing transaction is central to trimipramine maleate commercialization. Partnership value is more likely to arise from:

• Contract manufacturing of hard-gelatin capsules.
• Active-ingredient supply agreements.
• Specialty pharmacy distribution.
• Institutional and long-term-care contracting.
• Development partnerships for oral liquid or ODT products.
• Licensing of taste-masking or multiparticulate technology.

A licensing transaction would be most defensible where the partner owns a validated dosage-form platform or a patent family covering a specific formulation. A license for ordinary capsule excipients would add cost without creating meaningful exclusivity.

Key Takeaways

• Trimipramine maleate is a mature, off-patent tricyclic antidepressant with generic capsule availability.
• The conventional 25 mg, 50 mg and 100 mg capsule market is price-sensitive and has limited patent protection.
• A simple immediate-release capsule remains the lowest-risk product strategy.
• Lactose-free formulation, improved supply reliability and institutional packaging offer modest differentiation.
• Oral liquid, sprinkle-compatible and ODT products offer higher commercial upside but require greater formulation and regulatory investment.
• A new patent position would need to cover a technically specific formulation, stability improvement, taste-masking system or manufacturing process.
• Paragraph IV litigation, settlement leverage and Orange Book exclusivity are not expected to materially shape a standard capsule launch.
• The main commercial risks are therapeutic substitution, low pricing power, limited market size and overdose-related safety concerns.
• The most attractive opportunity is a regulated, reliable dosage form directed to swallowing-impaired, geriatric and institutional patients.

FAQs

Can trimipramine maleate be reformulated as an oral solution?

Yes, but the formulation would need to resolve solubility, taste, pH, preservation, dosing accuracy and container-closure stability. A suspension may be more practical than a true solution if aqueous solubility is inadequate.

Is trimipramine maleate suitable for an orally disintegrating tablet?

Potentially. The principal technical barriers are bitterness, dose loading, tablet friability and rapid uniform disintegration. Taste-masked granules or coated particles may be required.

Can a lactose-free trimipramine capsule support a patent?

A lactose-free composition alone would usually provide limited patent strength. Patent value would improve if the formulation delivered a non-obvious stability, dissolution, impurity or manufacturing benefit.

Would a new trimipramine liquid obtain new market exclusivity?

A new dosage form may qualify for regulatory exclusivity only if the applicable statutory requirements are met. A formulation change does not automatically create exclusivity or block competing capsule products.

Which packaging is best for trimipramine maleate capsules?

High-barrier blister packaging or a tightly closed bottle with desiccant should be evaluated. The selection should follow moisture, stability, transport and in-use testing rather than packaging convention.

References

National Library of Medicine. (2024). Trimipramine maleate capsule: Drug labeling. DailyMed. https://dailymed.nlm.nih.gov/

U.S. Food and Drug Administration. (2023). Applications covered by section 505(b)(2). https://www.fda.gov/

U.S. Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations. Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/

U.S. Food and Drug Administration. (2024b). Abbreviated new drug application submissions: Regulatory requirements and considerations. https://www.fda.gov/

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