List of Excipients in Branded Drug CHLORPROMAZINE

Generic Drugs Containing CHLORPROMAZINE

Company	Ingredient	NDC	Excipient
NCS HealthCare of KY Inc dba Vangard Labs	chlorpromazine hydrochloride	0615-1546	D&C RED NO. 30
NCS HealthCare of KY Inc dba Vangard Labs	chlorpromazine hydrochloride	0615-1546	D&C YELLOW NO. 10
NCS HealthCare of KY Inc dba Vangard Labs	chlorpromazine hydrochloride	0615-1546	FD&C BLUE NO. 2

What are the Most Frequently-Used Excipients in CHLORPROMAZINE?

# Of NDCs	Excipient
1	CELLULOSE, MICROCRYSTALLINE
1	CROSCARMELLOSE SODIUM
2	CROSPOVIDONE

Chlorpromazine Excipient Strategy and Commercial Opportunities

Last updated: August 25, 2026

Chlorpromazine is a mature, off-patent phenothiazine antipsychotic with limited conventional patent protection and low generic-entry barriers. Commercial opportunity is concentrated in formulation execution: palatability, liquid-dose accuracy, photostability, preservative reduction, excipient tolerability, packaging, and supply reliability. The most attractive opportunities are differentiated oral liquids, patient-specific dose formats, and robust injectable presentations rather than new chemical-entity exclusivity.

What is the current FDA and commercial status of chlorpromazine?

Chlorpromazine hydrochloride is marketed in multiple dosage forms, including tablets, oral concentrates or solutions, and injectable products. FDA-approved labeling identifies indications that include schizophrenia, acute manic states, severe behavioral problems, nausea and vomiting, and intractable hiccups, although the exact indication set varies by product and label.[1-4]

Attribute	Chlorpromazine status
Active ingredient	Chlorpromazine hydrochloride
Drug class	First-generation phenothiazine antipsychotic
Original U.S. approval era	1950s
Current U.S. status	Generic and legacy-product market
Common dosage forms	Tablets, oral liquid/concentrate, injection
Reference brand	Thorazine
Biologic status	Not applicable
Biosimilar pathway	Not applicable
Conventional composition patents	Generally expired or commercially immaterial
Main regulatory pathway for new products	ANDA, 505(b)(2), or drug-repurposing pathway depending on product
Primary commercial differentiators	Usability, excipient profile, stability, packaging, supply, and administration convenience

The commercial market is fragmented across manufacturers and dosage strengths. Labels and inactive-ingredient profiles differ by manufacturer, strength, and dosage form. A company evaluating chlorpromazine should therefore analyze each National Drug Code and each approved label separately rather than treat "chlorpromazine" as a single formulation.

When does chlorpromazine lose exclusivity?

Chlorpromazine’s original small-molecule exclusivity has expired. The product does not have a meaningful remaining innovator exclusivity period comparable to a recently approved branded drug.

Chlorpromazine was developed and approved decades before the modern Hatch-Waxman framework. Any original compound, composition, or basic formulation patent protection is no longer a practical barrier to generic development. Current commercial protection depends on manufacturing capability, formulation know-how, regulatory execution, customer contracts, and supply-chain performance.

What is the patent expiration outlook for chlorpromazine?

A single current patent expiration date does not define the market because the original drug and its basic formulations are long off patent. Any active patent found in a contemporary search would more likely concern a narrow formulation, delivery system, manufacturing process, or combination rather than chlorpromazine itself.

Potentially relevant claim categories include:

• Modified-release oral dosage forms.
• Taste-masked or orally disintegrating formulations.
• Transdermal or transmucosal delivery.
• Injectable stabilizer systems.
• Specific particle-size or crystallinity controls.
• Combination products.
• Narrow therapeutic-use claims.

The practical risk is low for standard immediate-release tablets and conventional chlorpromazine hydrochloride injection. Risk rises only where a proposed product copies a currently enforceable narrow formulation or method-of-use claim.

What patents protect chlorpromazine products?

For standard chlorpromazine hydrochloride tablets, oral liquids, and injections, commercial protection is primarily regulatory and operational rather than patent-based.

Are chlorpromazine products listed in the Orange Book?

The FDA Orange Book is the relevant source for approved drug applications, therapeutic equivalence evaluations, patent listings, and exclusivity data.[5] A prospective applicant should verify current listings for the specific dosage form and reference product. Legacy generic chlorpromazine products generally do not present a substantial Orange Book patent barrier.

Orange Book relevance is highest when:

1. An applicant files an ANDA referencing a listed product.
2. The referenced product has an unexpired listed patent.
3. The applicant seeks approval before patent expiry and must address the patent.
4. A Paragraph IV certification creates litigation exposure.

For a mature chlorpromazine product, the expected Paragraph IV exposure is limited. A Paragraph IV strategy would be more plausible for a newly listed narrow formulation than for conventional tablets or injection.

Which companies are challenging chlorpromazine patents?

No major active patent challenge is broadly associated with standard chlorpromazine products. The market is dominated by generic competition and legacy manufacturers rather than active patent litigation.

A diligence review should still examine:

• Current Orange Book patent listings.
• Abbreviated New Drug Application filings.
• Paragraph IV notices.
• FDA approval letters.
• Patent assignments involving formulation or delivery technology.
• District-court and Federal Circuit litigation concerning any listed patent.

Without a current product-specific patent family and listing, a company should not assume that chlorpromazine has enforceable formulation exclusivity.

What excipient strategy is appropriate for chlorpromazine tablets?

Immediate-release tablets are the lowest-risk development path. The formulation objective is usually reliable disintegration, content uniformity, mechanical strength, chemical stability, and low manufacturing cost.

A conventional tablet platform may use:

• A diluent such as lactose, microcrystalline cellulose, or dibasic calcium phosphate.
• A binder such as povidone or pregelatinized starch.
• A disintegrant such as crospovidone, croscarmellose sodium, or sodium starch glycolate.
• A lubricant such as magnesium stearate.
• A glidant such as colloidal silicon dioxide.
• Film-coating polymers, plasticizers, pigments, and opacifiers.

The correct selection depends on the target strength, manufacturing process, dissolution profile, and compatibility data. Chlorpromazine hydrochloride products should be evaluated for light sensitivity and chemical degradation during development. Packaging and coating may be as important as the core excipient system.

Which tablet opportunities are commercially differentiated?

The strongest tablet opportunities are practical rather than pharmacologically novel:

Opportunity	Commercial value	Development consideration
Smaller tablet	High for geriatric and psychiatric patients	Requires dose uniformity and adequate strength
Film-coated tablet	Moderate	Can improve swallowability and light protection
Low-lactose or lactose-free tablet	Moderate	Supports excipient-sensitive patients
Dye-free tablet	Moderate	Reduces colorant exposure and simplifies positioning
Scored tablet	High where dose splitting is clinically appropriate	Must demonstrate splitability and uniformity
Orally disintegrating tablet	Potentially high	Taste masking is the main technical barrier
Abuse-deterrent or modified-release tablet	Uncertain	Requires substantial clinical and regulatory justification

A scored, easy-to-swallow, low-colorant tablet may be more commercially credible than a complex modified-release product. Chlorpromazine’s clinical use often involves dose titration, which creates value for strength breadth, tablet splitting, and packaging clarity.

What excipients are important for chlorpromazine oral liquids?

Oral liquids provide the clearest formulation opportunity because chlorpromazine has a strong, bitter taste and is frequently used in patients who have difficulty swallowing tablets.

An oral liquid or concentrate may include:

• Purified water or another aqueous vehicle.
• A cosolvent such as glycerin or propylene glycol.
• A sweetener such as sucrose, sorbitol, or a high-intensity sweetener.
• A flavor system.
• A buffer or pH-adjusting agent.
• A preservative where the multidose container requires antimicrobial protection.
• A viscosity modifier.
• A chelating agent or antioxidant when supported by stability data.
• A wetting or solubilizing system if needed for concentration and clarity.

How should chlorpromazine liquid taste be managed?

Taste masking is a central commercial issue. Chlorpromazine’s bitterness can reduce adherence, especially in pediatric, geriatric, cognitively impaired, and psychiatric populations.

Potential approaches include:

1. Sweetener and flavor optimization. This is the least complex approach but may not adequately mask the active ingredient.
2. Viscosity enhancement. A more viscous vehicle can reduce immediate taste perception but may affect dose withdrawal and swallowing.
3. Ion-pairing or complexation. These methods can reduce free drug at the taste receptors but require careful dissolution and bioavailability testing.
4. Microencapsulation. Polymer coating can improve taste masking but increases process complexity and may affect release.
5. Multiparticulate suspension. Useful when a fully dissolved product is unstable or excessively bitter.
6. Unit-dose packaging. Does not mask taste but improves dose accuracy and may reduce administration errors.

A liquid developer should avoid assuming that a sweetener system alone will create a differentiated product. The commercial claim must be supported by comparative palatability data, stability data, and dose-delivery testing.

Which chlorpromazine liquid formats have the strongest opportunity?

Liquid format	Opportunity
Preservative-free unit-dose solution	Strong in institutional and high-risk patient settings
Sugar-free oral solution	Useful for diabetes-conscious and long-term-use populations
Alcohol-free product	May improve acceptability and institutional use
Ready-to-administer cup or syringe	Reduces dosing errors
Concentrate with calibrated dispenser	Lowers shipping volume but increases dilution risk
Taste-masked suspension	Potentially differentiated but technically complex
Multi-strength liquid platform	Supports titration and formulary contracts

A preservative-free, alcohol-free, sugar-free presentation with an oral syringe would offer a clear positioning strategy if chemical and microbiological stability can be demonstrated.

What excipients are used in chlorpromazine injection?

Chlorpromazine injection is a higher-risk dosage form because excipient selection must address sterility, particulate control, pH, container compatibility, precipitation, light exposure, and injection-site tolerability.

Approved injectable labels commonly identify chlorpromazine hydrochloride with inactive ingredients such as sodium chloride, sodium sulfite or another sulfite-related stabilizing system, and water for injection, although the exact composition varies by manufacturer and strength.[3,4]

Potential injectable formulation elements include:

• Water for injection.
• Sodium chloride for tonicity.
• pH adjusters.
• Antioxidants or sulfite-based stabilizers where justified.
• Chelating agents in selected systems.
• Low-adsorption container and closure components.

The development target should be a clear, stable, sterile solution that maintains potency throughout shelf life and minimizes precipitation or discoloration. The label-specific requirement to protect the product from light must be assessed during formulation and packaging development.[3,4]

What commercial opportunities exist for chlorpromazine injection?

The main opportunities are supply and administration improvements:

• Ready-to-use unit-dose syringes.
• Small-volume parenteral presentations.
• Preservative-reduced or preservative-free formats.
• Improved light-protective packaging.
• Latex-free and low-extractables container systems.
• Clear labeling for route and concentration.
• Institutional presentations with lower medication-preparation burden.

Injectable reformulation carries higher regulatory risk than tablet reformulation. Any change in pH, concentration, antioxidant system, container, or route can affect local tolerability, stability, and comparability. A 505(b)(2) pathway may be relevant for a materially different formulation, while a conventional ANDA may be appropriate where the product can match the reference product’s qualitative and quantitative composition and other requirements.

How strong is the chlorpromazine patent estate?

The patent estate is weak for standard products and potentially stronger only for new delivery or formulation technologies.

Patent category	Expected strength for standard chlorpromazine
Original compound patent	Expired
Basic hydrochloride salt claims	Expired or commercially immaterial
Immediate-release tablet claims	Low
Conventional oral solution claims	Low
Standard injection composition	Low
Taste-masked formulation	Potentially moderate
Orally disintegrating formulation	Potentially moderate
Long-acting delivery	Potentially stronger, but clinical and regulatory burden is high
New combination therapy	Product-specific
Manufacturing process	Potentially enforceable if narrow and non-obvious

A new formulation can generate patentable subject matter, but patentability does not guarantee meaningful commercial exclusivity. The claims must be difficult to design around, supported by comparative performance, and relevant to a product that physicians, hospitals, or payers will adopt.

What regulatory exclusivity is available for chlorpromazine reformulations?

A conventional generic chlorpromazine product is unlikely to receive meaningful new chemical-entity exclusivity. A reformulated product may qualify for limited regulatory protections depending on the statutory pathway and the nature of the innovation.

Potential mechanisms include:

• Three-year exclusivity for certain applications containing new clinical investigations essential to approval.
• Five-year new chemical entity exclusivity is generally not expected for a previously approved active ingredient.
• Orphan-drug exclusivity only if the product satisfies orphan designation and approval requirements.
• Pediatric exclusivity only through the statutory pediatric-study process.
• Patent protection for novel formulation, delivery, or manufacturing claims.

FDA’s 505(b)(2) pathway can support approval of a modified dosage form or route using information partly derived from existing literature or prior FDA findings, but the sponsor must establish the product’s safety, efficacy, quality, and labeling basis.[6]

What generic entry risks exist for chlorpromazine?

Generic entry risk is already high for standard oral and injectable products because:

• The active ingredient is old and widely known.
• Basic patent protection has expired.
• Manufacturing technology is established.
• Multiple dosage forms have historical regulatory precedents.
• Clinical differentiation is limited for conventional products.
• Institutional buyers often prioritize price and supply continuity.

The main barriers are operational:

• Reliable active pharmaceutical ingredient supply.
• Light-protective packaging.
• Stability in liquid and injectable presentations.
• Sterile manufacturing capacity.
• Low-volume commercial economics.
• Pharmacovigilance and labeling maintenance.
• Consistent supply across multiple strengths.

For a new entrant, shortages or discontinuations by incumbent suppliers may create the most credible commercial opening. FDA drug-shortage data and manufacturer availability should be monitored because a technically ordinary product can gain market share when supply is unreliable.[7]

What manufacturing and intellectual-property barriers affect chlorpromazine?

Manufacturing barriers differ by dosage form.

Tablets

The principal barriers are low-cost scale, dissolution matching, content uniformity, and efficient packaging. These barriers are manageable for established generic manufacturers.

Oral liquids

The principal barriers are taste masking, microbial control, preservative performance, container compatibility, and accurate dose delivery. A calibrated oral syringe and child-resistant packaging can improve product utility but add validation and packaging costs.

Injection

The principal barriers are sterile fill-finish capacity, particulate control, oxygen and light management, container closure integrity, and stability under shipping conditions. These requirements can limit competition even without patent protection.

Trade-secret protection may be more valuable than patents for:

• Taste-masking process parameters.
• Mixing and homogenization conditions.
• Antioxidant and buffer optimization.
• Container-selection data.
• Sterile filling and hold-time controls.
• Stability-indicating analytical methods.

How does chlorpromazine compare with competing antipsychotics?

Chlorpromazine competes with other first-generation antipsychotics such as haloperidol, fluphenazine, and perphenazine, and with newer atypical antipsychotics including risperidone, quetiapine, and olanzapine.

Factor	Chlorpromazine	Newer antipsychotics
Patent position	Largely expired	Product-specific, often stronger
Price	Generally low	Ranges from generic to premium
Sedation and tolerability	Can limit use	Product-dependent
Liquid availability	Commercially relevant opportunity	Often broader or more modern
Institutional use	Established in selected settings	Common across many indications
Formulation differentiation	Underdeveloped relative opportunity	More competitive
Commercial growth potential	Niche and supply-driven	Larger but more crowded

Chlorpromazine’s advantage is established clinical familiarity and low acquisition cost. Its weakness is tolerability and the age of the formulation portfolio. An excipient-led product should target administration reliability and patient acceptance rather than attempt to reposition the active ingredient as a broad modern antipsychotic.

What licensing deals and partnership opportunities exist?

The most credible partnership opportunities are commercial and manufacturing arrangements rather than licenses to foundational chlorpromazine patents.

Potential counterparties include:

• Generic pharmaceutical companies with ANDA capabilities.
• Contract development and manufacturing organizations.
• Sterile injectable manufacturers.
• Hospital and institutional distributors.
• Specialty pharmacies.
• Pediatric and geriatric formulation companies.
• Packaging suppliers with unit-dose and oral-syringe platforms.

A licensing transaction would be more defensible if it includes a protected delivery technology, a validated taste-masking platform, or an established sterile product with regulatory history. A license covering only conventional chlorpromazine hydrochloride composition is unlikely to create significant value.

What revenue exposure and commercial scenarios should investors model?

Chlorpromazine revenue is likely to be modest relative to major branded antipsychotics. Exposure depends on dosage form and customer segment.

Scenario	Product strategy	Revenue profile
Commodity tablet entrant	Standard strengths and low price	Low margin, volume-dependent
Institutional liquid supplier	Unit-dose or calibrated liquid	Moderate niche value
Sterile injectable supplier	Reliable injection supply	Higher strategic value during shortages
Premium oral-liquid developer	Taste-masked, sugar-free, alcohol-free	Higher margin but greater development risk
Specialty 505(b)(2) product	New delivery or indication	Potentially higher value, high clinical risk
Platform license	Excipients, taste masking, packaging	Royalty value depends on enforceable claims

The strongest near-term business case is a focused oral-liquid or injectable product supported by reliable supply and differentiated packaging. A broad portfolio of standard tablets is less attractive unless the manufacturer has a cost or distribution advantage.

Key Takeaways

• Chlorpromazine is a mature, off-patent generic drug with no meaningful original exclusivity remaining.
• Standard tablets and conventional injections face high generic-entry risk and limited patent protection.
• Excipient strategy has the greatest commercial value in oral liquids and injectable products.
• Taste masking, sugar-free and alcohol-free vehicles, preservative reduction, and calibrated dosing can support product differentiation.
• Light protection and chemical stability are important formulation and packaging considerations.
• Injectable development has higher technical and regulatory barriers because of sterility, stability, particulate, and container requirements.
• A 505(b)(2) strategy may be relevant for materially differentiated formulations, but it carries greater development cost and clinical risk than a conventional ANDA.
• Manufacturing reliability, shortage mitigation, and institutional supply contracts are more important than legacy patent ownership.
• The most credible licensing targets are delivery, taste-masking, packaging, or sterile-manufacturing platforms.
• Commercial success will depend on usability and supply continuity rather than exclusivity around chlorpromazine itself.

Frequently Asked Questions

Can a new chlorpromazine oral liquid receive patent protection?

Yes. A novel composition, taste-masking system, delivery device, or stability solution may support patent claims if it is new, non-obvious, adequately described, and commercially relevant. Basic chlorpromazine liquid formulations are unlikely to provide strong new protection.

Is chlorpromazine suitable for an orally disintegrating tablet?

It is technically possible, but bitterness, dose loading, mechanical strength, and moisture sensitivity require careful development. Taste masking is the main product risk.

Does chlorpromazine have biosimilar competition?

No. Chlorpromazine is a small-molecule drug, so competing products are generics rather than biosimilars.

Which chlorpromazine dosage form offers the best commercial opportunity?

A differentiated oral liquid or a reliable injectable product generally offers more opportunity than a conventional immediate-release tablet. The preferred format depends on access to sterile manufacturing, institutional customers, and formulation technology.

Can excipient changes support an ANDA for chlorpromazine?

Only within the regulatory limits applicable to the reference product and dosage form. Material differences in composition, route, release profile, or performance may require a 505(b)(2) application or additional regulatory justification rather than a standard ANDA.

References

1. DailyMed. (n.d.). Chlorpromazine hydrochloride tablet, film coated: Prescribing information. U.S. National Library of Medicine.
2. DailyMed. (n.d.). Chlorpromazine hydrochloride oral concentrate: Prescribing information. U.S. National Library of Medicine.
3. DailyMed. (n.d.). Chlorpromazine hydrochloride injection: Prescribing information. U.S. National Library of Medicine.
4. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs.
5. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book.
6. U.S. Food and Drug Administration. (2019). Applications covered by section 505(b)(2).
7. U.S. Food and Drug Administration. (n.d.). Drug shortages.