List of Excipients in Branded Drug COMPAZINE

Generic Drugs Containing COMPAZINE

Company	Ingredient	NDC	Excipient
PBM Pharmaceuticals Inc	prochlorperazine	66213-200	GLYCERIN
PBM Pharmaceuticals Inc	prochlorperazine	66213-200	GLYCERYL MONOSTEARATE
PBM Pharmaceuticals Inc	prochlorperazine	66213-200	GLYCERYL PALMITATE
PBM Pharmaceuticals Inc	prochlorperazine	66213-200	HYDROGENATED COCONUT OIL
PBM Pharmaceuticals Inc	prochlorperazine	66213-200	PALM KERNEL OIL

What are the Most Frequently-Used Excipients in COMPAZINE?

# Of NDCs	Excipient
1	GLYCERIN
1	GLYCERYL MONOSTEARATE
1	GLYCERYL PALMITATE
1	HYDROGENATED COCONUT OIL
1	PALM KERNEL OIL

Compazine Excipient Strategy and Commercial Opportunities

Last updated: August 2, 2026

Compazine is the historical brand name for prochlorperazine, a phenothiazine dopamine D2 receptor antagonist used primarily for severe nausea and vomiting and, in some formulations, schizophrenia. Its commercial opportunity is not based on active-ingredient exclusivity. Prochlorperazine was approved decades ago, and the current opportunity is concentrated in differentiated generics, excipient-controlled formulations, hospital supply, shortage mitigation, and alternative dosage forms.

The strongest product concepts are preservative-controlled injectables, low-excipient oral tablets, pediatric and geriatric formulations, orally disintegrating tablets, and rectal dosage forms with improved tolerability and supply reliability.

What is Compazine and which dosage forms are commercially relevant?

Compazine contains prochlorperazine, supplied as prochlorperazine maleate in oral products and prochlorperazine edisylate in injectable products. Historical and generic products have included tablets, suppositories, and injectable solutions.

Dosage form	Typical strength range	Primary commercial use	Excipient priority
Oral tablet	5 mg, 10 mg	Nausea, vomiting, selected psychiatric indications	Swallowability, low allergen burden, content uniformity
Rectal suppository	2.5 mg, 5 mg, 25 mg	Nausea and vomiting when oral administration is difficult	Base selection, melting profile, stability
Injectable solution	Commonly 5 mg/mL equivalent	Acute nausea and vomiting, hospital use	Preservative system, container compatibility, particulate control
Orally disintegrating tablet or oral film	Potential lifecycle form	Patients unable to swallow conventional tablets	Taste masking, rapid disintegration, moisture protection

The original Compazine brand is not the principal commercial asset. Generic prochlorperazine products and institutional contracts drive current market access. FDA labeling identifies prochlorperazine products by active moiety, salt form, dosage form, strength, and manufacturer rather than by a single uniform excipient profile (U.S. Food and Drug Administration [FDA], n.d.-a).

What excipients are used in Compazine and generic prochlorperazine?

Excipient composition differs by manufacturer and dosage form. The historical oral tablet platform commonly relies on conventional fillers, binders, disintegrants, lubricants, and coating materials. Injectable and rectal products require materially different excipient strategies.

Oral tablet excipients

Generic prochlorperazine maleate tablets may use combinations of:

• Lactose or a lactose-free filler
• Microcrystalline cellulose
• Corn starch or pregelatinized starch
• Povidone or another binder
• Croscarmellose sodium or sodium starch glycolate
• Magnesium stearate
• Talc
• Film-coating polymers, pigments, and plasticizers

The commercial issue is not whether the excipients are technically conventional. It is whether the formulation delivers consistent dissolution, acceptable tablet robustness, low friability, and broad patient tolerability at low cost.

A lactose-free version has a clear positioning advantage for patients with lactose intolerance or for institutions seeking simplified excipient specifications. The product should not imply that lactose intolerance is equivalent to milk-protein allergy. Those are different clinical issues.

Suppository excipients

Rectal prochlorperazine products historically use fatty suppository bases such as cocoa butter or hard-fat systems. The base controls:

• Melting or softening at body temperature
• Drug dispersion
• Release rate
• Storage stability
• Physical integrity during shipping
• Patient handling

A hard-fat base can improve manufacturing consistency and reduce dependence on cocoa butter variability. A synthetic triglyceride base may also offer better control of polymorphism, melting range, and oxidative stability.

The commercial constraint is patient acceptance. Rectal dosage forms remain useful when vomiting prevents oral administration, but demand is narrower than for tablets or injections.

Injectable excipients

Prochlorperazine edisylate injection requires a parenteral-grade formulation with control of pH, tonicity, oxidation, light exposure, and container interaction. Depending on the approved product, excipient categories may include:

• Water for injection
• Sodium chloride or another tonicity agent
• pH-adjusting agents
• Antioxidant or sulfite-based stabilizers in selected products
• Preservative systems in multidose presentations, where permitted

The injectable formulation has the highest technical and regulatory burden. A sulfite-containing product can create labeling and procurement issues for institutions that prefer sulfite-free presentations. A preservative-free single-dose vial can support operating-room, emergency-department, and pediatric use, but it may carry higher packaging and manufacturing costs.

Exact excipient claims must be taken from the current manufacturer label and inactive-ingredient listing. Compazine should not be treated as one fixed formulation across all suppliers.

Which excipient strategies create the strongest commercial opportunities?

The most attractive strategy is to match excipient differentiation with a specific purchasing or administration problem.

1. Preservative-free injectable prochlorperazine

A preservative-free single-dose vial or ready-to-use presentation could target hospitals, emergency departments, ambulatory surgery centers, and pediatric settings. The value proposition would include:

• Reduced preservative exposure
• Simplified dose preparation
• Lower risk of bedside dilution errors
• Compatibility with institutional preservative restrictions
• Improved suitability for single-patient administration

The principal development barriers are container closure integrity, adsorption, extractables and leachables, particulate control, photostability, and aseptic manufacturing. A prefilled syringe could improve workflow but would require device, human-factors, and stability work.

2. Sulfite-free injection

A sulfite-free formulation could address institutions that avoid sulfite-containing products or require clear excipient differentiation. The development challenge is replacing oxidative protection without compromising assay, impurity profile, or shelf life.

This opportunity is commercially credible only if the formulation obtains a stable shelf life in the intended container. A sulfite-free label alone is not enough to displace an established low-price generic.

3. Orally disintegrating tablet

An orally disintegrating tablet could address patients with acute nausea, dysphagia, difficulty accessing water, or limited ability to retain a conventional tablet. The formulation program would focus on:

• Rapid disintegration
• Taste masking
• Low friability
• Moisture resistance
• Minimal packaging volume
• Dose uniformity at low strength

Prochlorperazine can produce central nervous system adverse effects, including sedation and extrapyramidal reactions. An orally disintegrating dosage form should not be marketed as safer merely because it dissolves in the mouth. The differentiation is administration convenience.

A taste-masked ODT could potentially be pursued through an ANDA if it meets the reference product requirements, or through a 505(b)(2) pathway if the dosage form or clinical bridging strategy falls outside standard ANDA conditions. FDA’s regulatory pathway depends on the reference listed drug, dosage form, strength, route, and proposed labeling (FDA, n.d.-b).

4. Low-excipient and lactose-free tablets

A lactose-free tablet is a lower-risk formulation opportunity than an ODT or injectable reformulation. It can support hospital formularies, specialty pharmacies, and patients who avoid lactose-containing medicines.

The product must preserve bioequivalence and acceptable mechanical properties. Removing lactose can alter tablet hardness, disintegration, dissolution, and blend uniformity. A direct-compression platform using microcrystalline cellulose, mannitol, or dibasic calcium phosphate may provide alternatives, but each changes density, mouthfeel, and compression behavior.

5. Improved suppository base

A modern hard-fat suppository can reduce variability associated with natural cocoa butter and improve temperature tolerance during distribution. The strongest positioning would be supply reliability and manufacturing consistency rather than premium pricing.

A suppository remains commercially relevant for acute nausea when oral dosing is impractical. Its market is smaller, but competition may also be less intense than for standard tablets.

What FDA regulatory pathway applies to a differentiated Compazine product?

A conventional generic prochlorperazine tablet would normally be developed through an ANDA referencing the applicable prochlorperazine listed drug. The applicant must demonstrate pharmaceutical equivalence and bioequivalence and meet current chemistry, manufacturing, and controls requirements.

A 505(b)(2) application may be relevant for a materially different formulation, delivery system, route, or dosing presentation that relies in part on FDA’s findings for a previously approved product. Potential examples include:

• Orally disintegrating tablets
• Oral films
• New injectable presentations
• Device-enabled delivery
• Modified excipient systems requiring a bridging rationale

The pathway does not eliminate the need to address safety, clinical pharmacology, product quality, and labeling. A 505(b)(2) product may also face patent certification and regulatory exclusivity issues if relevant listed patents or exclusivity remain associated with the reference product.

What patents protect Compazine and when does prochlorperazine lose exclusivity?

Prochlorperazine is an old small-molecule drug. The original compound, historical formulations, and early use patents are generally far beyond their ordinary patent terms. The commercial risk therefore centers on product-specific patents, regulatory exclusivity, manufacturing know-how, and supply economics rather than core-molecule patent protection.

Protection category	Relevance to prochlorperazine
Original compound patent	Historical and expired
Original use patents	Historical and generally expired
Modern formulation patents	Must be assessed by product and jurisdiction
Device patents	Relevant to prefilled syringes, films, or combination presentations
ANDA regulatory exclusivity	Depends on the specific reference product and approval history
Trade secrets	Potentially relevant to impurity control, sterilization, and scale-up
Manufacturing capacity	High practical importance for injectable supply

The Orange Book should be reviewed for the current reference listed drug, listed patents, patent certifications, and any 30-month stay information. FDA’s Orange Book identifies approved drug products and, where applicable, patent and exclusivity information (FDA, n.d.-c).

What is the Orange Book status of Compazine?

The relevant Orange Book analysis should distinguish the discontinued Compazine brand from currently approved prochlorperazine products. A product may be discontinued commercially while its active ingredient remains available through generic approvals. The key diligence items are:

1. The current reference listed drug for each dosage form.
2. Whether the listed product is marketed.
3. Whether any patents are listed against the reference product.
4. Whether a proposed formulation can use an ANDA or requires 505(b)(2).
5. Whether the proposed product would require a Paragraph IV certification.
6. Whether any regulatory exclusivity remains active.

Because prochlorperazine has been marketed for many years, a new entrant is more likely to face routine ANDA competition than a blocking innovator patent. The risk profile changes for a new dosage form or delivery device.

Which companies are challenging Compazine, and what is the litigation status?

The relevant competitors are generic manufacturers and contract manufacturers of prochlorperazine tablets, suppositories, and injections. Prochlorperazine has no widely recognized current patent dispute comparable to litigation involving recently approved branded drugs.

Paragraph IV litigation would arise only if an ANDA applicant certified that a listed patent was invalid, unenforceable, or not infringed. For an old active ingredient, litigation risk is more likely to attach to a newer formulation, delivery device, or method-of-use patent than to prochlorperazine itself.

A prospective entrant should monitor:

• FDA ANDA approvals
• Orange Book patent additions
• District court complaints following Paragraph IV notices
• Abbreviated new drug application settlements
• Drug shortage listings
• Manufacturer discontinuations
• Warning letters and manufacturing remediation

No settlement should be assumed from the historical brand name alone. The relevant agreements would be product-specific and should be verified through court filings, SEC disclosures, or FDA records.

How strong is the patent estate for Compazine?

The patent estate for the legacy active ingredient is weak as a barrier to ordinary generic entry. A differentiated product can still create a narrower patent position around:

• Specific excipient ratios
• Taste-masking systems
• ODT manufacturing processes
• Stabilized injectable compositions
• Preservative-free container systems
• Suppository base combinations
• Prefilled syringe configurations
• New dosing regimens or administration methods

The strength of these patents would depend on claim breadth, unexpected technical effect, prior-art density, enablement, written description, and ability to obtain meaningful injunctive or settlement leverage. Narrow formulation patents often protect a commercial product but do not block all alternative formulations.

What generic launch risks exist for a new Compazine formulation?

A generic or reformulated product faces five principal launch risks.

Price compression

Standard prochlorperazine tablets are likely to be low-price products with limited room for premium excipient positioning. The business case depends on manufacturing efficiency, supply reliability, and institutional contracts.

Limited market growth

Prochlorperazine competes with ondansetron, metoclopramide, promethazine, and other antiemetics. Prescribing patterns and hospital protocols may limit demand even when the product is technically differentiated.

Safety-related formulary controls

Sedation, orthostatic hypotension, anticholinergic effects, extrapyramidal symptoms, and neuroleptic malignant syndrome warnings affect use. An excipient improvement does not remove active-ingredient safety constraints (DailyMed, n.d.).

Injectable manufacturing complexity

Sterile manufacturing failures can produce recalls, shortages, and regulatory intervention. Injectable prochlorperazine offers more defensible technical differentiation but requires higher capital and quality-system investment.

Reference-product ambiguity

The correct reference listed drug and product-specific labeling must be established before selecting an ANDA or 505(b)(2) strategy. A product that differs in route, strength, presentation, or dosage form may not fit a conventional generic pathway.

How does Compazine compare with competing antiemetics?

Product	Main opportunity	Excipient differentiation potential	Competitive pressure
Prochlorperazine	Low-cost antiemetic and hospital supply	Moderate to high in injection, ODT, and suppository forms	High
Ondansetron	Broad use and strong prescriber familiarity	ODT, film, and taste masking	High
Promethazine	Oral, rectal, and injectable use	Formulation and preservative strategy	High
Metoclopramide	Nausea and gastrointestinal indications	Oral liquid and ODT opportunities	High
Dimenhydrinate or meclizine	Motion sickness and vestibular indications	Chewable and liquid forms	Moderate

Prochlorperazine’s advantage is established clinical familiarity and multiple administration routes. Its disadvantage is a less favorable adverse-effect profile than several newer antiemetic options, limiting premium commercial positioning.

What licensing deals and manufacturing partnerships are relevant?

The most practical partnership models are:

• Contract development and manufacturing for sterile injection
• Licensing of ODT or oral-film technology
• Suppository-base technology licensing
• Regional distribution agreements
• Hospital group purchasing contracts
• Authorized generic arrangements
• Dual-source supply agreements

A licensee should seek rights covering the formulation, manufacturing process, regulatory dossier, trademarks, and geographic territories. For injectable products, the agreement should allocate responsibility for aseptic validation, stability commitments, pharmacovigilance, recalls, and shortage response.

Compazine itself is not a strong platform for a broad brand licensing strategy. The higher-value asset is a differentiated prochlorperazine product with a defensible regulatory position and reliable supply.

What geographic opportunities exist for prochlorperazine?

The United States offers an ANDA-driven opportunity with strong competition and price pressure. Europe and other regulated markets may offer opportunities through national generic registrations, hospital tenders, or hybrid applications, but requirements differ by jurisdiction.

Geographic differentiation may be strongest where:

• Injectable antiemetic supply is constrained
• Rectal products remain clinically accepted
• Hospital procurement favors dual sourcing
• Preservative-free products are preferred
• Local competitors have limited sterile capacity

A global program should not assume that the same salt form, excipient package, labeling, or reference product can be used in every market.

Key Takeaways

• Compazine is the historical brand for prochlorperazine, an old small-molecule antiemetic and antipsychotic.
• Core active-ingredient patent protection is not the principal barrier to entry.
• Commercial value is concentrated in differentiated generics, sterile supply, and alternative dosage forms.
• Preservative-free or sulfite-free injections offer the strongest technical opportunity but carry the highest manufacturing burden.
• ODTs, oral films, lactose-free tablets, and improved suppository bases offer more targeted lifecycle opportunities.
• Conventional tablets are likely to face substantial price competition.
• Orange Book, DailyMed, FDA approval records, and current manufacturer labels must be reviewed by dosage form and reference product.
• Formulation and device patents may protect a new product even though legacy prochlorperazine patents have expired.
• Hospital contracts and supply reliability may be more important than brand recognition.
• Biosimilar risk is not relevant because prochlorperazine is a chemically synthesized small molecule, not a biologic.

FAQs

Is Compazine still a branded drug or only a generic opportunity?

Compazine is primarily a historical brand reference. Current commercial activity is centered on generic prochlorperazine products and potential differentiated formulations.

Can a lactose-free prochlorperazine tablet obtain FDA approval through an ANDA?

Yes, if it references the appropriate listed drug and meets pharmaceutical equivalence, bioequivalence, quality, and labeling requirements. A novel formulation or delivery feature may require a 505(b)(2) application instead.

Is prochlorperazine suitable for an orally disintegrating film?

Potentially. The key technical issues are taste masking, dose uniformity, moisture control, disintegration time, packaging, and bioequivalence or clinical bridging.

Are biosimilars a competitive threat to Compazine?

No. Prochlorperazine is a synthetic small molecule. Competition comes from generic drug manufacturers, not biosimilar developers.

Which Compazine formulation has the greatest commercial defensibility?

A sterile, preservative-controlled injectable product has the highest potential technical defensibility. Its value depends on validated stability, reliable aseptic manufacturing, and hospital purchasing demand.

References

1. DailyMed. (n.d.). Prochlorperazine maleate and prochlorperazine edisylate prescribing information. U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/

2. U.S. Food and Drug Administration. (n.d.-a). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/

3. U.S. Food and Drug Administration. (n.d.-b). 505(b)(2) applications. https://www.fda.gov/drugs/types-applications/abbreviated-new-drug-application-anda

4. U.S. Food and Drug Administration. (n.d.-c). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

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