Dimercaprol - Generic Drug Details

What are the generic drug sources for dimercaprol and what is the scope of patent protection?

Dimercaprol is the generic ingredient in one branded drug marketed by Provepharm Sas and is included in one NDA. Additional information is available in the individual branded drug profile pages.

There is one tentative approval for this compound.

Summary for dimercaprol

US Patents:	0
Tradenames:	1
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	87
What excipients (inactive ingredients) are in dimercaprol?	dimercaprol excipients list
DailyMed Link:	dimercaprol at DailyMed

Generic filers with tentative approvals for DIMERCAPROL

Applicant	Application No.	Strength	Dosage Form
		10%	INJECTABLE;INJECTION

The 'tentative' approval signifies that the product meets all FDA standards for marketing, and, but for the patents / regulatory protections, it would approved.

Medical Subject Heading (MeSH) Categories for dimercaprol

Chelating Agents

Anatomical Therapeutic Chemical (ATC) Classes for dimercaprol

V03AB	Antidotes
V03A	ALL OTHER THERAPEUTIC PRODUCTS
V03	ALL OTHER THERAPEUTIC PRODUCTS
V	Various

US Patents and Regulatory Information for dimercaprol

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Provepharm Sas	BAL	dimercaprol	INJECTABLE;INJECTION	005939-001	Approved Prior to Jan 1, 1982		RX	Yes	Yes

Dimercaprol Market Dynamics, Patent Protection, FDA Status, and Financial Trajectory

Last updated: September 12, 2026

Dimercaprol is a mature, low-volume injectable antidote used for arsenic, gold, mercury, and severe lead poisoning. Its commercial market is structurally small, procurement-driven, and exposed to supply interruptions because demand is episodic and manufacturing requires sterile injectable capacity. The product has no meaningful remaining composition-of-matter patent protection, no conventional branded growth strategy, and limited public financial disclosure. Its value lies in medical necessity and scarcity rather than prescription volume.

What is dimercaprol and how is it used?

Dimercaprol, also known as British Anti-Lewisite or BAL, is an intramuscular chelating agent. The U.S. product is generally supplied as a 100 mg/mL injectable solution in oil.

FDA labeling identifies the following uses:

• Arsenic poisoning
• Gold poisoning
• Mercury poisoning
• Severe lead poisoning, in combination with edetate calcium disodium
• Certain heavy-metal poisoning cases in which rapid parenteral chelation is required

Dimercaprol is administered by deep intramuscular injection. Dosing varies by toxicant, severity, time since exposure, and clinical response. Treatment can require repeated injections over several days, creating a high clinical burden and increasing the importance of hospital stock availability.

The product has important limitations. It can cause hypertension, tachycardia, nausea, vomiting, headache, fever, pain at the injection site, and other adverse reactions. It is contraindicated or poorly suited for some patients, including individuals with peanut allergy where peanut oil is used in the formulation. Dimercaprol is not a general-purpose replacement for oral chelators such as succimer or calcium disodium edetate. (U.S. Food and Drug Administration, n.d.-a)

What is the FDA regulatory status of dimercaprol?

Dimercaprol is an FDA-approved prescription drug supplied as an injectable antidote. The product is regulated as a conventional small-molecule drug, not as a biologic.

Regulatory attribute	Dimercaprol
Active ingredient	Dimercaprol
Common name	British Anti-Lewisite, BAL
Dosage form	Intramuscular injectable solution
Typical strength	100 mg/mL
Therapeutic class	Heavy-metal chelating agent
FDA pathway	Legacy NDA and/or generic-equivalent regulatory pathway
Prescription status	Prescription only
Biologic status	Not a biologic
Main institutional users	Hospitals, poison centers, emergency departments, public-health stockpiles
Primary clinical demand	Acute poisoning treatment

Dimercaprol is part of the U.S. emergency antidote supply chain. Procurement is typically handled by hospitals, group purchasing organizations, wholesalers, poison-treatment centers, and government or public-health entities rather than through retail pharmacy demand.

The product is commercially distinct from succimer, edetate calcium disodium, penicillamine, and deferoxamine. Those products address overlapping toxicology markets but do not provide a direct substitute in every poisoning scenario.

What is the Orange Book status of dimercaprol?

Dimercaprol has limited commercial relevance under the FDA Orange Book framework because its original product dates from the pre-modern patent era and its principal market is an established generic injectable.

The Orange Book identifies approved drug products and, where applicable, patent and regulatory-exclusivity information. A current Orange Book review should be used to confirm the precise listed product, holder, and approval pathway because legacy products can appear under different application histories or commercial sponsors. No commercially meaningful unexpired U.S. patent estate is associated with dimercaprol as an active ingredient. (U.S. Food and Drug Administration, n.d.-b)

Does dimercaprol have active formulation patents?

No significant active U.S. formulation patent position is apparent for the established 100 mg/mL oil-based injection. The formulation is technically simple compared with modern depot injections, liposomes, prefilled delivery systems, or complex biologics.

Potential formulation differentiation could involve:

• Replacement of peanut oil with another vehicle
• Reduced injection pain
• Alternative concentration
• Improved stability
• Ready-to-use emergency packaging
• Autoinjector or other delivery system
• A formulation designed for patients with peanut sensitivity

These changes would require separate FDA development and approval work. They would not automatically create broad protection for the underlying dimercaprol molecule.

When does dimercaprol lose exclusivity?

Dimercaprol lost meaningful molecule-level exclusivity decades ago. Its active ingredient was developed during World War II and has been used clinically for many years. Any original composition-of-matter patent rights have expired.

Exclusivity category	Status
Composition-of-matter patent	Expired
Original clinical exclusivity	Expired
Modern new-drug exclusivity	None of material commercial relevance identified
Pediatric exclusivity	None identified
Orphan-drug exclusivity	None identified for the established product
Formulation patent estate	No material active U.S. estate identified
Method-of-use patent estate	No material active U.S. estate identified
Regulatory market protection	Driven primarily by approval status and supply availability

The commercial barrier is therefore manufacturing and market economics, not patent exclusion.

How many patents cover dimercaprol?

There is no material active U.S. patent estate covering the conventional dimercaprol injection. Historical patents and expired references may appear in patent databases, but they do not prevent generic manufacture or marketing.

A future sponsor could seek patents around:

• A new injectable vehicle
• A non-intramuscular delivery route
• An autoinjector
• A stable premixed emergency kit
• A combination treatment regimen
• A novel manufacturing process

Such patents would protect only the claimed improvement. They would not block conventional dimercaprol products unless the claims were drafted broadly enough to cover the underlying formulation or use, which would face substantial validity and prior-art risks.

Are there Paragraph IV challenges to dimercaprol?

No prominent recent Paragraph IV litigation involving dimercaprol is publicly associated with a commercially important patent dispute. The reason is straightforward: the established product lacks a valuable, unexpired patent portfolio that would justify a major patent challenge.

Generic entry could occur through an ANDA or another applicable abbreviated pathway. A challenger would likely focus on demonstrating pharmaceutical equivalence, bioequivalence where applicable, injectable quality, sterility, container compatibility, and manufacturing compliance rather than defeating patents.

Litigation issue	Commercial assessment
Paragraph IV challenge	No major public dispute identified
Patent-invalidity litigation	Low probability absent a new formulation patent
ANDA competition	Legally feasible
FDA manufacturing review	Material
Patent settlement risk	Low
Supply-based market disruption	High relative to patent risk

What manufacturing and intellectual-property barriers affect dimercaprol?

The principal barriers are operational.

Dimercaprol is an oil-based sterile injectable. A manufacturer must maintain validated aseptic processing, appropriate container-closure systems, reliable raw-material sourcing, stability data, quality-control procedures, and FDA-compliant production capacity. A small market makes it difficult to spread fixed costs across sufficient unit volume.

Key manufacturing risks include:

1. Sterile injectable capacity. Production requires specialized facilities and validated processes.
2. Raw-material controls. Dimercaprol and the oil vehicle must meet pharmaceutical quality specifications.
3. Container compatibility. The formulation must remain stable in its vial or other approved container.
4. Low production frequency. Infrequent campaigns can increase setup and inventory costs.
5. Limited supplier redundancy. Few manufacturers may consider the market economically attractive.
6. Emergency inventory requirements. Hospitals and government agencies may expect product availability even though routine demand is low.

The result is a market in which regulatory and quality systems matter more than patent ownership.

Which companies are challenging or supplying dimercaprol?

Dimercaprol has historically been associated with specialty generic and hospital-product manufacturers rather than large branded pharmaceutical companies. Akorn Pharmaceuticals marketed BAL in Oil in the United States under its legacy hospital-drug portfolio. Akorn filed for bankruptcy protection in 2023 and subsequently underwent a wind-down and asset disposition process, creating uncertainty around products associated with its portfolio. (U.S. Bankruptcy Court, 2023)

Public disclosures do not provide a reliable, product-level ranking of current dimercaprol manufacturers, market shares, or sales. The market should therefore be analyzed through FDA approval records, current labeling, wholesaler availability, hospital purchasing data, and FDA shortage information rather than company-wide revenue releases.

No major innovator company is known to be pursuing a branded, high-growth dimercaprol strategy. No prominent biosimilar competitors exist because dimercaprol is a small molecule, not a biologic.

What patent litigation affects dimercaprol?

No material active patent litigation involving conventional dimercaprol is apparent from the public record. The most relevant legal risks are likely to involve:

• FDA approval disputes
• Manufacturing compliance
• Product-quality investigations
• Contract and supply agreements
• Antitrust or allocation issues if supply becomes concentrated
• Product-liability claims tied to adverse reactions or administration errors

Patent litigation would become more plausible only if a company introduced a new delivery system, alternative formulation, or combination product with a defensible patent position.

How does dimercaprol compare with competing chelation drugs?

Dimercaprol remains differentiated by its parenteral route and role in serious acute poisoning, but competing products can reduce routine demand.

Product	Main use	Route	Commercial effect on dimercaprol
Dimercaprol	Arsenic, gold, mercury, severe lead poisoning	Intramuscular	Core product
Succimer	Lead and selected heavy-metal poisoning	Oral	Reduces use when oral treatment is clinically appropriate
Edetate calcium disodium	Lead poisoning	Intravenous or intramuscular	Used with or instead of dimercaprol in selected cases
Penicillamine	Selected chronic metal toxicities	Oral	Limited acute substitution
Deferoxamine	Iron and aluminum toxicity	Parenteral	Different toxicology indication
Prussian blue	Thallium and radioactive cesium	Oral	Different toxicology indication

Dimercaprol has particular value in severe arsenic and mercury poisoning and in severe lead poisoning with encephalopathy. It is less attractive for outpatient or chronic treatment because of its injection burden and adverse-effect profile.

What drives the dimercaprol market?

The market is driven by clinical necessity rather than disease prevalence.

Demand drivers

• Rare industrial, occupational, environmental, and intentional poisonings
• Hospital emergency preparedness
• Poison-control recommendations
• Government stockpiling
• Limited therapeutic substitutes for specific toxicants
• Requirement for immediate availability in severe cases

Demand constraints

• Very low incidence of eligible poisonings
• Use restricted to acute toxicology events
• Availability of oral or less burdensome chelators in selected cases
• Injection-related adverse events
• Product shelf-life and inventory carrying costs
• Small number of institutional buyers

Demand is highly irregular. A manufacturer can experience long periods of low orders followed by abrupt institutional or emergency demand. That pattern makes forecasting difficult and can produce apparent shortages even when annual consumption is small.

What is the financial trajectory for dimercaprol?

No reliable public source discloses global dimercaprol revenue, U.S. net sales, gross margin, or product-level profitability. Public-company filings generally report hospital or generic portfolios in aggregate.

The likely financial trajectory has four phases:

Period	Market condition	Financial profile
Historical development	Government and military toxicology need	Development and adoption driven by public-health necessity
Mature generic period	Expired patents and established clinical use	Low-volume, low-growth product
Supply-constrained period	Fewer manufacturers and intermittent availability	Potential price increases and higher inventory value
Current strategic period	Specialty antidote procurement	Stable but volatile revenue; limited commercial upside

Unit prices can appear high relative to manufacturing cost because they must support specialized sterile production, regulatory compliance, inventory carrying costs, distribution, and the risk of unsold or expired stock. High price per vial does not imply high total market revenue.

The strongest financial opportunity is usually not volume expansion. It is dependable supply, government contracting, portfolio bundling with other antidotes, and operational control over a scarce sterile product.

What generic launch risks exist for dimercaprol?

A new generic entrant would face low patent risk but meaningful execution risk.

Regulatory risk

The applicant would need to establish equivalence to the reference product and satisfy FDA requirements for injectable quality, sterility, stability, labeling, and manufacturing controls. Legacy products can create complexity when historical approval records, reference standards, or labeling histories are fragmented.

Commercial risk

The total addressable market may be too small to support multiple manufacturers. A new entrant could gain approval yet fail to reach attractive utilization because hospitals buy infrequently and may prefer a supplier with a proven antidote portfolio.

Supply risk

A single raw-material disruption or sterile manufacturing deviation could remove the product from the market. The low-volume economics may discourage redundant capacity.

Pricing risk

If several suppliers enter, pricing pressure could reduce margins quickly. If only one or two suppliers remain, scarcity could support higher prices but also increase regulatory and reputational scrutiny.

What licensing deals and settlement agreements involve dimercaprol?

No significant publicly disclosed licensing deal or patent settlement focused specifically on conventional dimercaprol has been identified. Commercial rights have primarily followed generic-product ownership, product-line acquisitions, and manufacturer portfolio changes rather than major technology licenses.

A future transaction would more likely involve:

• Acquisition of an approved injectable product
• Transfer of an ANDA or legacy NDA
• Contract manufacturing
• Government supply agreements
• Combination sales with other emergency antidotes

The absence of major licensing activity reflects the product’s limited revenue ceiling and lack of active patent leverage.

What geographic markets are relevant?

The United States is the most visible market because FDA-approved labeling, hospital purchasing, and public-health procurement are documented. Dimercaprol is also used internationally, but product names, strengths, regulatory status, and suppliers differ.

Geographic commercial factors include:

• National poison-control infrastructure
• Industrial exposure patterns
• Government antidote stockpiles
• Local sterile-injectable manufacturing capacity
• Import requirements
• Currency and reimbursement conditions
• National treatment guidelines

The product’s low-volume profile makes country-by-country registration economically selective. Manufacturers are more likely to pursue jurisdictions with centralized procurement or a recognized emergency-antidote program.

Key Takeaways

• Dimercaprol is a mature, small-molecule emergency antidote with no material remaining composition-of-matter exclusivity.
• Its principal U.S. dosage form is a 100 mg/mL oil-based intramuscular injection.
• The market is driven by acute poisoning events, hospital preparedness, and public-health procurement.
• Patent litigation and Paragraph IV risk are low for the conventional product.
• Sterile manufacturing, supply continuity, and regulatory compliance are the main barriers to entry.
• Akorn’s 2023 bankruptcy and wind-down increased concern about supplier continuity for legacy hospital products.
• No reliable public source reports dimercaprol-specific revenue or market share.
• Financial returns depend on scarcity, dependable supply, portfolio economics, and institutional contracts rather than prescription growth.
• Biosimilar competition is irrelevant because dimercaprol is a conventional small molecule.
• A new entrant would face low patent risk but substantial market-size, quality, and manufacturing risk.

FAQs about dimercaprol market and exclusivity

Is dimercaprol still FDA approved?

Yes. Dimercaprol remains an FDA-regulated prescription injectable antidote for selected heavy-metal poisonings.

Is dimercaprol listed in the Orange Book?

The relevant FDA approval and patent status should be confirmed through the current Orange Book and Drugs@FDA records because legacy products can appear under different application histories. No material unexpired patent protection is associated with the conventional active ingredient.

Can a generic company launch dimercaprol without a Paragraph IV challenge?

Potentially. If no relevant unexpired patent blocks approval, an applicant can pursue the applicable abbreviated or conventional FDA pathway without mounting a major Paragraph IV patent challenge.

Is dimercaprol a profitable drug?

It can generate attractive unit economics in a supply-constrained setting, but the total market is small and demand is irregular. Product-level profitability depends heavily on manufacturing utilization, inventory losses, pricing, and institutional contracts.

Does dimercaprol have biosimilar competition?

No. Biosimilars apply to biologic products. Dimercaprol is a conventional small-molecule drug, so competition would come from generic injectable manufacturers.

References

1. U.S. Bankruptcy Court for the District of Delaware. (2023). In re Akorn Operating Company LLC, et al., Chapter 11 bankruptcy proceedings. PACER.

2. U.S. Food and Drug Administration. (n.d.-a). Dimercaprol injection prescribing information. FDA and DailyMed labeling records.

3. U.S. Food and Drug Administration. (n.d.-b). 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

4. Agency for Toxic Substances and Disease Registry. (n.d.). Medical management guidelines for arsenic, lead, mercury, and other heavy-metal exposures. U.S. Department of Health and Human Services.

5. National Library of Medicine. (n.d.). Dimercaprol drug labeling and clinical information. DailyMed. https://dailymed.nlm.nih.gov/