piperazine citrate - Profile

What are the generic sources for piperazine citrate and what is the scope of freedom to operate?

Piperazine citrate is the generic ingredient in five branded drugs marketed by Glaxosmithkline, Sanofi Aventis Us, Bluline, Alpharma Us Pharms, Lannett, Luitpold, Solvay, and Impax Labs, and is included in eight NDAs. Additional information is available in the individual branded drug profile pages.

Summary for piperazine citrate

US Patents:	0
Tradenames:	5
Applicants:	8
NDAs:	8

US Patents and Regulatory Information for piperazine citrate

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Glaxosmithkline	ANTEPAR	piperazine citrate	SYRUP;ORAL	009102-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Sanofi Aventis Us	BRYREL	piperazine citrate	SYRUP;ORAL	017796-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Bluline	MULTIFUGE	piperazine citrate	SYRUP;ORAL	009452-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Alpharma Us Pharms	PIPERAZINE CITRATE	piperazine citrate	SYRUP;ORAL	080774-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Lannett	PIPERAZINE CITRATE	piperazine citrate	SYRUP;ORAL	080963-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Luitpold	PIPERAZINE CITRATE	piperazine citrate	SYRUP;ORAL	080671-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Solvay	VERMIDOL	piperazine citrate	SYRUP;ORAL	080992-001	Approved Prior to Jan 1, 1982		DISCN	No	No

Last updated: July 12, 2026

Piperazine Citrate drug investment scenario and IP/regulatory fundamentals analysis (2026)

Executive summary: Piperazine citrate is a small-molecule salt form of piperazine used primarily as an intermediate/actives ingredient and in select therapeutic and chemical applications. An “investment scenario” for piperazine citrate depends less on blockbuster-style clinical pipelines and more on (1) whether the commercial product is sold as a finished pharmaceutical drug with an FDA-approved NDA/ANDA/BLA track, (2) how IP is structured around the salt form, polymorph/solvate, particle size, and manufacturing process, and (3) whether major market channels treat it as a commodity intermediate with limited enforceable patent thickets. Without an identified FDA application and an Orange Book listing for a specific finished dosage product, the practical risk profile trends toward commodity exposure: low margins, high price elasticity, and limited defensibility beyond process know-how and regulatory filings.

The sections below map the investability drivers: regulatory status framing (NDA/ANDA track vs. non-pharma commodity usage), likely patent coverage patterns for salts/formulations/manufacturing, expected exclusivity dynamics, generic/contract-manufacturing risk, and valuation implications for different buyer profiles.

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Is piperazine citrate an FDA-approved finished drug, an intermediate, or a commodity chemical?

Featured snippet answer: Piperazine citrate is commonly marketed and used as a chemical substance and intermediate. Investment-grade fundamentals require confirming whether a specific finished pharmaceutical product has an FDA approval that triggers Orange Book protections and paragraph IV litigation.

What to look for in FDA sources to classify investability

For investment underwriting, the critical determinant is whether piperazine citrate appears as:

• An API for a finished dosage form under an NDA/ANDA (regulatory entry driver).
• A bulk drug substance used in compounding or non-NDA markets (lower price protection).
• A chemical intermediate used in synthesis (commodity economics).

Why this classification drives valuation

• If it is an intermediate, pricing is typically anchored to feedstock costs (piperazine) and downstream synthesis demand, not patent exclusivity.
• If it is a finished FDA-approved drug, value shifts to label-protected indications, exclusivity, and manufacturing IP plus regulatory barriers (CMC, bioequivalence, stability, and controlled manufacturing).

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What patents protect piperazine citrate salt forms, polymorphs, or manufacturing processes?

Featured snippet answer: For salt-form small molecules, enforceable IP often concentrates in process claims, specific polymorph/solvate forms, particle-size/solid-state specifications, and stability/handling methods, not the base structure itself.

Typical patent estate structure for salt forms

For a molecule like piperazine (highly known chemistry), patents that remain litigable years later usually target:

• Salt formation parameters (solvent systems, temperatures, crystallization sequences).
• Isolated solid-state forms (specific polymorphs, hydrate forms, solvate retention).
• Particle engineering (D50/D90 ranges, micronization, morphology control).
• Stability and storage windows (impurity profile control; moisture sensitivity).
• Manufacturing process steps (reactant order, purification/filtration conditions).

What is usually weak for salt-only “me-too” products

• Broad “piperazine citrate” claims without tying to a specific form or process often face validity risk.
• If the market regards it as an established chemical, the base composition is likely prior art, compressing enforceable term.

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How strong is the patent estate for piperazine citrate versus generic and commodity substitutes?

Featured snippet answer: The more the market treats piperazine citrate as an established salt without an FDA exclusivity tied to a finished product, the more the effective patent value becomes “process-defensive,” not “market-exclusionary.”

Commercial defensibility hierarchy

1. Finished drug protections (indications, dosage form, formulation, use) give the strongest exclusionary value.
2. CMC-specific protections can block some generic entries even if composition is known.
3. Process patents protect manufacturing but do not necessarily stop sale if alternative processes exist.
4. Salt identity alone usually yields limited long-lived defensibility.

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When does piperazine citrate lose exclusivity?

Featured snippet answer: Exclusivity loss is driven by the specific FDA approval governing the product’s label and its reference listed drug (RLD). For piperazine citrate as a commodity chemical, there is no FDA exclusivity framework in the usual sense.

If a finished drug NDA exists

Exclusivity timing depends on:

• New chemical entity (NCE) exclusivity (5 years).
• Orphan exclusivity (7 years, if applicable).
• Pediatric exclusivity extensions (up to 6 months).
• Orphan designation and pediatric plans.
• Patent expiration schedule per Orange Book listings.

If piperazine citrate is an intermediate/API

There is no FDA-driven exclusivity loss; the limiting factor becomes:

• patent strength around form/process,
• downstream customer switching costs,
• qualification requirements at customer sites.

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What Orange Book status exists for piperazine citrate products?

Featured snippet answer: Orange Book status is product-specific. Investment underwriting requires identifying whether piperazine citrate appears as the active ingredient in an FDA-approved finished dosage product with listed patents.

Why Orange Book drives investability

Orange Book listings typically define:

• listed patents tied to drug product,
• expiration dates relevant to generic entry,
• risk of paragraph IV certifications.

What “absence” usually means commercially

If no Orange Book listing exists for piperazine citrate as the active ingredient in a finished drug:

• expect fewer legal barriers for new entrants,
• anticipate pricing pressure from qualified suppliers,
• treat differentiation as CMC and quality systems rather than exclusivity.

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Are there paragraph IV filings or patent litigation related to piperazine citrate?

Featured snippet answer: Paragraph IV frameworks require an ANDA referencing an FDA-approved RLD. If piperazine citrate functions as an intermediate, paragraph IV litigation is generally not the main risk channel.

Litigation channels that still matter

Even without paragraph IV:

• process patent disputes,
• trade secret/CIC (customer qualification) conflicts,
• quality incidents that trigger customer bans,
• regulatory holds linked to impurity or stability failures.

Litigation mapping for salt-form products

When litigation does occur for salt forms, claims often cluster around:

• specific crystalline forms (polymorph),
• impurity specifications (e.g., residual solvents/amines),
• drying conditions and residual water.

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What generic entry risks exist for piperazine citrate?

Featured snippet answer: The generic risk resembles a supplier substitution risk more than a label substitution risk, unless piperazine citrate is part of a finished FDA product with Orange Book-listed patents.

Key entry risks for suppliers

• Qualification lag: customers requalify lots and can delay switching 6 to 18 months depending on regulatory regime and internal SOPs.
• Quality systems as barrier: GMP documentation, microbial/impurity control, and reproducible crystallization are switching costs.
• Specs and compliance: customers often demand tighter specs than basic chemical standards.

Batch-to-batch defensibility

Competitors can match endpoints if they can reproduce:

• solid-state form,
• particle-size distribution,
• impurity profile and moisture content,
• stability under real-world shipping.

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How does piperazine citrate compare with competing piperazine salts or alternative APIs?

Featured snippet answer: Competitive position is typically determined by:

• solubility and handling,
• stability and shelf life,
• downstream compatibility with finished drug manufacturing,
• cost-to-spec ratio.

What typically differentiates salts in procurement

• Crystallization yield and scalability during production.
• Moisture uptake and caking behavior.
• Residual solvent management to meet customer specs.
• Consistency of solid form affecting downstream dissolution and formulations.

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What formulations or dosage forms use piperazine citrate and how does that affect IP?

Featured snippet answer: IP shifts from “salt identity” to “formulation and method-of-use” if piperazine citrate is used as a therapeutic component in a finished product with clinical labeling.

Formulation patent leverage points

If piperazine citrate is incorporated into finished dosage forms:

• sustained-release or controlled-release solid-state systems,
• specific excipient compatibility enabling stability,
• dissolution-rate targeting.

Where IP is usually thin

If use is limited to:

• simple aqueous solutions,
• non-proprietary tablets/capsules,
• common compounding contexts, then formulation IP is more likely to be expired or non-existent.

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Which companies are likely major suppliers or competitors for piperazine citrate?

Featured snippet answer: Major players tend to be chemical manufacturers and API/specialty chemical suppliers with solid-state capabilities and regulatory documentation. The competitor set is typically broad and global.

Competitive landscape considerations for investors

• Capacity concentration lowers pricing power.
• Regional logistics and shipping risk matter due to bulk chemical handling.
• Customer qualification favors suppliers with established pharma-grade QA and CMO relationships.

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What manufacturing/IP barriers protect piperazine citrate pricing?

Featured snippet answer: In a commodity-like market, the barriers are operational: crystallization control, reproducibility of the solid form, and stable impurity control rather than long-lived patent exclusivity.

CMC bottlenecks that create quasi-barriers

• validated crystallization and drying profiles to maintain form and residual moisture,
• impurity profile management (process-related amines/byproducts),
• scaling robustness to avoid form conversion.

Where patents can still matter

If patents exist on:

• specific polymorphs or solvate control,
• process parameters with narrow ranges tied to yield,
• purification sequences, they can create “prove-it” barriers to replication even when chemistry is known.

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Commercial fundamentals: is piperazine citrate an attractive margin product or a pass-through commodity?

Featured snippet answer: In most practical investment scenarios for established salts, piperazine citrate acts as a margin-thin commodity unless tied to an FDA-approved finished drug supply chain.

Margin drivers

• Feedstock costs (piperazine and citric acid availability).
• Energy and solvent costs for crystallization.
• Yield and losses during filtration and drying.
• Compliance overhead (GMP/DMF-style documentation vs. chemical grade).

Revenue stability drivers

• Long-term supply agreements with pharmaceutical customers.
• Ability to meet tight specs and consistent form.
• Low incidence of quality excursions.

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Investment scenario framework: how to underwrite piperazine citrate

Featured snippet answer: Underwrite the business as either (A) a regulated finished-drug supplier with IP-driven defensibility, or (B) a specialty chemical/commodity supplier with CMC-driven qualification defensibility.

A. If tied to an FDA-approved finished product

Key diligence items:

• Orange Book patent list and expiration schedule for the specific finished dosage product.
• Risk of generic substitution (Paragraph IV if ANDA exists).
• CMC transfer and equivalence risk (ability for entrants to match solid-state specs).
• Market concentration and procurement terms.

B. If a chemical intermediate or non-exclusivity active

Key diligence items:

• customer qualification requirements and typical switching time,
• validated impurity specs and reproducibility metrics,
• capacity and cost curve position,
• long-term contracts and pricing formulas.

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Key Takeaways

• Investability for piperazine citrate turns on whether it is part of an FDA-approved finished drug with Orange Book-listed patents and defined exclusivity timelines, or instead traded as an intermediate/commodity.
• For salt-form chemicals, enforceable IP, when available, usually clusters around solid-state form and manufacturing process controls, not broad composition coverage.
• Generic and price competition risk is typically supplier substitution, unless a specific finished product creates regulatory exclusivity and patent-driven barriers.
• The strongest “defensibility” in commodity-like markets usually comes from CMC reproducibility: crystallization outcomes, impurity profiles, and moisture/handling stability.
• Pricing power is most durable when coupled with long-term supply agreements, tight specs, and customer qualification lock-in.

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FAQs

1) What is the main business risk for investing in piperazine citrate production?
The main risk is that piperazine citrate behaves like a substitutable commodity chemical, so margins compress under capacity expansion unless tied to regulated finished-drug supply chains.

2) What patents matter most for piperazine citrate if it is sold as a salt with controlled solid-state properties?
Patents that claim specific polymorph/solvate forms, particle-size ranges, or validated crystallization and drying parameters tied to impurity and stability profiles.

3) Does piperazine citrate typically face paragraph IV ANDA litigation?
Paragraph IV frameworks generally require an ANDA tied to an FDA-approved RLD. If piperazine citrate is not the active ingredient in an Orange Book-listed finished drug, paragraph IV is not the principal risk channel.

4) What CMC capabilities most reduce competitive switching for piperazine citrate?
Demonstrated reproducibility of solid-state form, moisture control, and impurity specifications across scaled batches, supported by validated quality systems.

5) How do feedstock costs influence investor returns for piperazine citrate?
Returns are highly sensitive to piperazine and citric acid supply dynamics, plus energy/solvent costs tied to crystallization and drying yields.

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References (APA)

1. U.S. Food and Drug Administration. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. https://www.accessdata.fda.gov/scripts/cder/daf/
2. U.S. Food and Drug Administration. Drug Approval Reports / Drugs@FDA. https://www.accessdata.fda.gov/scripts/cder/daf/
3. U.S. Food and Drug Administration. Patent and Exclusivity Information for Drugs. https://www.fda.gov/drugs/therapeutic-biologics-applications/patent-and-exclusivity-information-drugs