QUALAQUIN Drug Patent Profile

When do Qualaquin patents expire, and what generic alternatives are available?

Qualaquin is a drug marketed by Sun Pharm Industries and is included in one NDA.

The generic ingredient in QUALAQUIN is quinine sulfate. There is one drug master file entry for this compound. Four suppliers are listed for this compound. Additional details are available on the quinine sulfate profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Qualaquin

A generic version of QUALAQUIN was approved as quinine sulfate by TEVA PHARMS on September 28^th, 2012.

Summary for QUALAQUIN

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	30
Clinical Trials:	3
Patent Applications:	2,559
Drug Prices:	Drug price information for QUALAQUIN
What excipients (inactive ingredients) are in QUALAQUIN?	QUALAQUIN excipients list
DailyMed Link:	QUALAQUIN at DailyMed

See drug prices for QUALAQUIN

Recent Clinical Trials for QUALAQUIN

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Mutual Pharmaceutical Company, Inc.	Phase 1

See all QUALAQUIN clinical trials

US Patents and Regulatory Information for QUALAQUIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Sun Pharm Industries	QUALAQUIN	quinine sulfate	CAPSULE;ORAL	021799-001	Aug 12, 2005		DISCN	Yes	No

Qualaquin Market Dynamics, Financial Trajectory, Patent Risk, and Generic Competition

Last updated: September 20, 2026

Qualaquin is quinine sulfate, a legacy antimalarial approved in the United States for uncomplicated Plasmodium falciparum malaria. Its commercial market is narrow because malaria is uncommon in the United States and current treatment guidelines favor artemisinin-based regimens. Qualaquin’s largest historical demand driver outside malaria was off-label treatment of nocturnal leg cramps, but FDA safety actions sharply reduced that use. Public company filings do not disclose standalone Qualaquin revenue, making the drug’s financial trajectory assessable through market structure, regulatory restrictions, and portfolio disclosures rather than audited product-level sales.

What is Qualaquin approved to treat?

Qualaquin is approved for the treatment of uncomplicated P. falciparum malaria. It is not approved for leg cramps, restless leg syndrome, or other muscle-cramp indications. The FDA label states that the drug should not be used to prevent or treat nocturnal leg cramps because the risks outweigh the unproven benefits for that use (FDA, 2013).

Attribute	Qualaquin profile
Active ingredient	Quinine sulfate
U.S. dosage form	324 mg capsule
FDA application	NDA 021799
Original U.S. approval	2005
Approved indication	Uncomplicated P. falciparum malaria
Primary therapeutic class	Antimalarial
U.S. market	Prescription, niche hospital and travel-medicine market
Major safety restrictions	Thrombocytopenia, hemolysis, QT prolongation, hypoglycemia, cinchonism
Leg-cramp status	Not FDA-approved; FDA advises against use

The approved indication is strategically important. Qualaquin does not compete across the broad malaria market. It competes in a limited U.S. segment involving imported malaria cases, situations involving drug resistance, and clinical circumstances in which physicians use quinine based on treatment availability or patient-specific considerations.

How large is the Qualaquin market?

The U.S. Qualaquin market is structurally small and volatile. Demand depends on imported malaria cases, hospital formularies, public-health procurement, travel patterns, and the availability of alternative antimalarial products.

The United States reports thousands of imported malaria cases in typical years, but those cases are distributed among multiple species and treatment regimens. CDC guidance generally prioritizes artemisinin-based combination therapy and other recommended antimalarial regimens over quinine when suitable alternatives are available (CDC, 2024).

Key market drivers

1. Imported malaria cases among travelers, immigrants, military personnel, and visiting populations.
2. Hospital and infectious-disease formulary decisions.
3. Drug shortages or limited access to preferred antimalarial therapies.
4. Resistance patterns and geographic exposure.
5. Public-health and emergency stockpiling requirements.

Key market constraints

The product has several structural disadvantages:

• Quinine has a narrow therapeutic index.
• Adverse events can require hospitalization or treatment discontinuation.
• The FDA warned that quinine is frequently used inappropriately for leg cramps.
• Artemisinin-based therapies have become the preferred treatment in many clinical settings.
• Malaria treatment is episodic rather than chronic.
• U.S. prescription volume is too small to support broad primary-care distribution.

Qualaquin therefore operates as a specialty rescue or alternative product rather than a high-volume outpatient medicine.

What is the financial trajectory of Qualaquin?

No major public company has consistently reported Qualaquin revenue as a standalone line item. Product-level sales are generally embedded within broader U.S. generic, branded-generic, or specialty portfolios. The available public record supports a declining or constrained commercial profile, but not a precise annual revenue series.

Financial factor	Effect on Qualaquin
Malaria treatment demand	Low and episodic
Historical off-label leg-cramp demand	Material source of volume but legally and medically restricted
Pricing power	Potentially high in a niche market, limited by generic substitution and scrutiny
Gross-margin profile	Potentially attractive at low manufacturing volume, but exposed to inventory and regulatory costs
Revenue visibility	Low because public filings do not isolate product sales
Growth prospects	Limited without a new indication or supply disruption
Downside risk	Generic competition, guideline displacement, safety restrictions, and discontinuation risk

The FDA’s 2010 safety communication was a major commercial inflection point. The agency reported serious hematologic adverse events associated with quinine and stated that the drug should not be used for leg cramps. The agency later required stronger communication of risks and continued to discourage off-label use (FDA, 2010; FDA, 2012).

The financial effect was likely a contraction in non-malaria demand. That contraction reduced the addressable outpatient market and left the product dependent on a small number of malaria-related prescriptions. A niche product can retain pricing power despite low volume, but revenue becomes vulnerable to hospital purchasing decisions, inventory rationalization, and supply interruptions.

When did Qualaquin lose exclusivity?

Qualaquin’s commercial exclusivity has largely expired. The drug was approved in 2005, and its market is no longer protected by a conventional new-drug exclusivity period. FDA approval of the reference product does not prevent later abbreviated new drug applications from entering if applicants satisfy the relevant bioequivalence and labeling requirements.

The principal commercial protection historically came from the branded product’s position as the reference drug, regulatory familiarity, and limited market economics. Those protections are weaker than an active patent estate.

Exclusivity category	Qualaquin status
New chemical entity exclusivity	Expired
Orphan-drug exclusivity	Not the principal protection for the marketed product
Pediatric exclusivity	No durable commercial barrier identified
Patent-based exclusivity	No commercially significant active patent barrier is evident from the core product history
Reference-listed-drug status	Relevant for generic development and substitution
Biosimilar exclusivity	Not applicable

The exact availability of generic competitors depends on current FDA approval records, manufacturing status, and commercial distribution. Quinine sulfate is an established small molecule, so any remaining market protection is more likely to arise from supply, manufacturing, or distribution constraints than from composition-of-matter exclusivity.

What patents protect Qualaquin?

Qualaquin is not protected by biologic exclusivity or a modern platform patent estate. Its active ingredient, quinine sulfate, is an old small molecule. The commercially relevant intellectual-property questions concern the product formulation, manufacturing controls, regulatory status, and any listed patents associated with the NDA.

The main patent-risk assessment is:

• No meaningful composition-of-matter patent protection remains for quinine sulfate.
• Any formulation or manufacturing patents would have limited value if they do not block an equivalent generic capsule.
• Method-of-use patents directed to malaria treatment would face narrow commercial scope because the approved use is already established and the active ingredient is old.
• Patents directed to leg-cramp treatment would have limited commercial value because FDA does not approve Qualaquin for that indication and discourages the use.
• Manufacturing know-how may affect supply quality but generally does not create the same barrier as an Orange Book-listed patent.

What formulation patents are relevant?

The marketed product is a hard gelatin capsule containing quinine sulfate at a 324 mg strength. A formulation patent would need to create a meaningful barrier around the capsule, release profile, stability, or manufacturing process. For an immediate-release quinine sulfate capsule, that barrier is likely narrower than for modified-release, injectable, or complex drug-delivery products.

The commercial importance of any formulation patent depends on whether the patent is listed in the FDA Orange Book, whether it covers the reference product rather than an optional formulation, and whether a generic applicant can design around it.

What is the Orange Book status of Qualaquin?

Qualaquin is an FDA-approved prescription drug associated with NDA 021799. The Orange Book is the relevant source for current reference-listed-drug status, therapeutic-equivalence codes, and any active listed patents or exclusivity entries (FDA, 2025).

The Orange Book analysis should focus on four issues:

1. Whether NDA 021799 remains active.
2. Whether Qualaquin remains designated as the reference listed drug.
3. Whether any patent expiration date is currently listed.
4. Whether approved ANDA products have an AB rating against the reference product.

Because Orange Book listings can change with application status, patent certifications, and marketing discontinuation records, the commercial interpretation should be based on the current FDA entry rather than historical labeling alone.

Which companies are challenging Qualaquin with generic products?

The relevant challengers are manufacturers of quinine sulfate capsules and distributors able to supply hospitals and pharmacies. The market is not defined by a single high-profile Paragraph IV campaign. It is defined by the economics of generic entry into a low-volume, safety-sensitive product.

A generic applicant would generally assess:

• Bioequivalence against the reference product.
• Capsule content uniformity and dissolution.
• Stability and impurity controls.
• Labeling consistency.
• Ability to maintain supply despite low annual demand.
• Pharmacovigilance obligations.
• Commercial reimbursement and wholesaler access.

What Paragraph IV challenges affect Qualaquin?

No major, commercially material Paragraph IV litigation campaign is established as a defining feature of Qualaquin’s market history. For an old drug with limited sales, a Paragraph IV challenge may offer less upside than a standard abbreviated new drug application, particularly if the market has limited volume and no active blocking patent.

If no relevant listed patent remains, generic applicants would not need to use a Paragraph IV certification to enter. They could rely on a Paragraph III certification, a section viii statement for nonprotected uses, or an application pathway consistent with the current Orange Book record.

Is there biosimilar risk for Qualaquin?

No. Qualaquin is a chemically synthesized small-molecule drug, not a biologic. Biosimilar pathways under the Public Health Service Act do not apply. Competitive risk comes from generic quinine sulfate products, therapeutic substitutes, and shifts in malaria treatment guidelines.

The more relevant substitutes include:

• Artemisinin-based combination therapies.
• Atovaquone/proguanil.
• Mefloquine in selected circumstances.
• Chloroquine where susceptibility remains appropriate.
• Intravenous artesunate for severe malaria.

These products reduce Qualaquin’s strategic importance even when they do not directly compete as interchangeable capsule products.

What litigation and settlement agreements affect Qualaquin?

Qualaquin’s primary legal exposure has involved regulatory and safety actions rather than patent litigation. The FDA issued safety communications concerning improper use for leg cramps and serious adverse events, including thrombocytopenia and hemolysis (FDA, 2010).

No settlement agreement is widely recognized as the central commercial event governing Qualaquin generic entry. The absence of a major settlement-driven delayed-entry framework limits the likelihood of a large, litigation-defined launch event.

The principal legal risks are instead:

• Product-liability claims involving bleeding or hemolysis.
• Failure-to-warn allegations related to off-label use.
• Manufacturing or supply-quality violations.
• False-marketing or promotion risk if the product is promoted for leg cramps.
• Pharmacy and payer substitution disputes involving generic availability.

What generic launch scenarios exist for Qualaquin?

Scenario 1: Stable niche supply

Qualaquin or an equivalent generic remains available for malaria treatment. Pricing stays relatively firm because volume is low and suppliers have limited incentives to compete aggressively.

Scenario 2: Generic price erosion

Multiple suppliers enter, creating reimbursement pressure and reducing brand sales. The market remains available, but the reference product loses formulary and pharmacy share.

Scenario 3: Supply disruption

One or more manufacturers exit because annual volume cannot support production, leaving hospitals dependent on a small supplier base. Prices may rise temporarily, but the total market remains small.

Scenario 4: Clinical displacement

Guideline-preferred therapies continue to displace quinine. Qualaquin remains available as a backup option but loses strategic value and may become commercially marginal.

The most probable long-term scenario is continued niche availability with low and irregular revenue, subject to generic supply and antimalarial procurement conditions.

How strong is the Qualaquin patent estate?

The patent estate is weak as a long-term commercial defense. Qualaquin’s value is based on regulatory approval, product familiarity, supply reliability, and niche pricing rather than exclusionary patent rights.

Patent-estate factor	Assessment
Active composition-of-matter protection	Weak or absent
Formulation protection	Limited commercial significance
Method-of-use protection	Narrow
Orange Book leverage	Dependent on current listing status
Manufacturing trade secrets	Possible but difficult to quantify
Litigation leverage	Low
Generic entry barrier	Primarily regulatory and economic

The manufacturing barrier may be more important than the patent barrier. Quinine sulfate requires controlled sourcing, consistent assay, impurity management, and reliable capsule production. Those factors can deter entry into a low-volume market, but they do not create durable exclusivity if a supplier decides the market is commercially viable.

How does Qualaquin compare with competing antimalarial drugs?

Product or class	Primary advantage over Qualaquin	Commercial effect
Artemisinin-based therapies	Guideline preference and strong efficacy for many malaria cases	Reduces first-line demand
Atovaquone/proguanil	Convenient oral dosing and broad travel-medicine use	Competes for uncomplicated malaria
Mefloquine	Established use in selected prophylaxis and treatment settings	Limits quinine’s role
Intravenous artesunate	Preferred treatment for severe malaria	Restricts quinine to alternative or special-use settings
Generic quinine sulfate	Lower price and potential therapeutic equivalence	Erodes brand share

Qualaquin’s competitive position is strongest when a physician needs quinine specifically, when preferred products are unavailable, or when clinical circumstances constrain alternatives. Its position is weak in routine travel medicine and standard first-line malaria treatment.

What is the geographic coverage of Qualaquin?

Qualaquin’s strongest commercial market is the United States because the product is FDA approved and tied to U.S. prescribing, hospital procurement, and Orange Book status. International markets are fragmented. Other countries may use quinine sulfate, quinine hydrochloride, or different antimalarial formulations under local approvals.

Geographic expansion is limited by:

• Different malaria species and resistance patterns.
• National treatment guidelines.
• Local registration requirements.
• Availability of artesunate and artemisinin combinations.
• Public-health procurement preferences.
• Local pricing and reimbursement controls.

The product does not have the geographic growth profile of a global chronic-care medicine.

Key Takeaways

• Qualaquin is quinine sulfate approved for uncomplicated P. falciparum malaria.
• The U.S. market is small, episodic, and driven by imported malaria rather than chronic use.
• FDA warnings against leg-cramp treatment materially reduced the historical off-label demand base.
• Standalone Qualaquin revenue is not disclosed in public filings.
• New-drug exclusivity has expired, and the long-term patent estate is weak.
• Generic competition, alternative antimalarials, and treatment guidelines are the main commercial pressures.
• Biosimilar risk does not apply because Qualaquin is a small-molecule drug.
• The strongest remaining commercial defenses are supply reliability, regulatory familiarity, and niche procurement relationships.
• The most likely financial trajectory is low, volatile revenue with limited growth and periodic exposure to supply shortages or generic price erosion.

FAQs

Is Qualaquin still available in the United States?

Qualaquin’s availability depends on the current NDA status, manufacturer distribution, wholesaler inventory, and generic supply. FDA approval and commercial availability are separate questions.

Why is Qualaquin not recommended for leg cramps?

FDA identified serious risks, including thrombocytopenia, hemolysis, QT prolongation, and hypoglycemia, while finding inadequate evidence of benefit for routine leg-cramp treatment (FDA, 2010).

Does Qualaquin have an AB-rated generic?

An AB rating depends on the current FDA Orange Book record and approved ANDA status. The rating can change as applications are approved, withdrawn, or discontinued.

Can a company obtain exclusivity for a new Qualaquin formulation?

A genuinely novel formulation could potentially receive patent protection or regulatory exclusivity if it satisfies statutory requirements. That protection would cover the claimed formulation, not necessarily all quinine sulfate products.

Is Qualaquin a high-value acquisition target?

Its value is more likely to arise from niche cash flow, supply positioning, or portfolio fit than from patent exclusivity or high growth. The absence of disclosed standalone revenue makes a product-level valuation dependent on verified prescription, pricing, and supply data.

References

Centers for Disease Control and Prevention. (2024). Treatment of malaria: Guidelines for clinicians. U.S. Department of Health and Human Services.

U.S. Food and Drug Administration. (2010). FDA drug safety communication: New risk management plan and medication guide for Qualaquin (quinine sulfate). U.S. Department of Health and Human Services.

U.S. Food and Drug Administration. (2012). FDA approves labeling changes for Qualaquin to address serious safety risks. U.S. Department of Health and Human Services.

U.S. Food and Drug Administration. (2013). Qualaquin (quinine sulfate) capsules prescribing information. U.S. Department of Health and Human Services.

U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book. U.S. Department of Health and Human Services.