DIABINESE Drug Patent Profile

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

Diabinese is a drug marketed by Pfizer and is included in one NDA.

The generic ingredient in DIABINESE is chlorpropamide. There is one drug master file entry for this compound. Additional details are available on the chlorpropamide profile page.

Summary for DIABINESE

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	87
Clinical Trials:	1
Patent Applications:	4,395
DailyMed Link:	DIABINESE at DailyMed

Recent Clinical Trials for DIABINESE

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

Sponsor	Phase
Novartis	Phase 2

See all DIABINESE clinical trials

US Patents and Regulatory Information for DIABINESE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pfizer	DIABINESE	chlorpropamide	TABLET;ORAL	011641-003	Approved Prior to Jan 1, 1982		DISCN	Yes	No
Pfizer	DIABINESE	chlorpropamide	TABLET;ORAL	011641-006	Approved Prior to Jan 1, 1982		DISCN	Yes	No

Diabinese Market Dynamics, Patent Status, FDA Exclusivity, and Financial Trajectory

Last updated: November 8, 2026

Diabinese, the brand name for chlorpropamide, is a legacy first-generation sulfonylurea for type 2 diabetes. It was introduced in 1958 and once held a meaningful position in oral diabetes treatment. Its commercial value declined as metformin, second-generation sulfonylureas, DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 receptor agonists, and insulin products displaced older therapies.

Diabinese has no material current U.S. commercial market. Its composition, formulation, regulatory, and method-of-use exclusivities expired decades ago. No current Orange Book patent position, Paragraph IV dispute, biosimilar issue, or active branded commercial franchise materially affects the product. Pfizer has not publicly reported standalone Diabinese revenue.

What is Diabinese and how was it used?

Diabinese is an oral tablet containing chlorpropamide, a first-generation sulfonylurea that stimulates pancreatic insulin secretion. It was approved for adults with type 2 diabetes when diet alone was inadequate and was used primarily before the widespread adoption of metformin-based treatment [1].

Chlorpropamide has a substantially longer duration of action than many later sulfonylureas. The long pharmacologic effect contributed to prolonged hypoglycemia, particularly in older adults and patients with renal impairment. The product labeling also identifies hyponatremia, alcohol-related reactions, and other adverse effects associated with chlorpropamide therapy [1].

Historical product profile

Attribute	Diabinese
Active ingredient	Chlorpropamide
Drug class	First-generation sulfonylurea
Original U.S. sponsor	Pfizer predecessor operations
Initial U.S. approval	1958
Dosage form	Oral tablet
Primary indication	Type 2 diabetes
U.S. regulatory status	Legacy/discontinued commercial product
Current Orange Book patent position	No meaningful active position identified
Current biosimilar relevance	None
Current commercial position	Minimal to nonexistent in the United States

When did Diabinese lose market exclusivity?

Diabinese lost meaningful market exclusivity many decades ago. The underlying small-molecule composition and early product patents would have expired long before the modern Hatch-Waxman framework became commercially important for this product.

The product has no remaining new chemical entity exclusivity, pediatric exclusivity, or market exclusivity. Modern generic applicants therefore do not face an active brand exclusivity barrier for chlorpropamide.

Diabinese exclusivity timeline

Period	Commercial and regulatory event
1958	U.S. approval of chlorpropamide under the Diabinese brand
1960s-1970s	Expansion of sulfonylurea use in type 2 diabetes
1970s onward	Patent protection and practical market exclusivity expired
1980s-1990s	Increasing substitution by metformin and newer sulfonylureas
2000s	Declining clinical use because of hypoglycemia and tolerability concerns
2010s	Limited availability and decreasing commercial relevance
Current period	No material U.S. branded market

The exact historical patent family is less commercially relevant than the legal outcome: any original Diabinese patent protection expired several decades ago, and no active Orange Book-listed patent now protects the product.

What is the Orange Book status of Diabinese?

Diabinese does not have a commercially meaningful current Orange Book position. FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book, is the principal U.S. reference for active approved products, therapeutic-equivalence evaluations, and listed patents [2].

The relevant distinction is between historical FDA approval and current commercial availability. A product can remain in FDA records while no longer being marketed. Diabinese belongs to that legacy category. Its historical NDA record does not create current patent protection or prevent generic development.

Current Orange Book implications

• No active brand exclusivity protects chlorpropamide.
• No material patent-listed barrier is expected to delay an abbreviated new drug application.
• Any generic applicant would rely on ordinary ANDA requirements, including pharmaceutical equivalence, bioequivalence, manufacturing controls, labeling, and supply capability.
• The principal commercial obstacle is demand, not intellectual property.

Are there Paragraph IV challenges to Diabinese?

No active, commercially significant Paragraph IV dispute involving Diabinese is identified. Paragraph IV litigation typically arises when a generic applicant challenges an Orange Book-listed patent before its expiration. That pathway has little practical relevance for chlorpropamide because the product’s core patent estate expired long ago and the branded market has largely disappeared.

A future chlorpropamide ANDA would more likely face a commercial viability question than a patent litigation question. A generic applicant could potentially file with a Paragraph III certification if any residual listed patent issue existed, but no such barrier appears material to the current product.

What patents protect Diabinese?

No active patent estate materially protects Diabinese in the United States.

Composition patents

Chlorpropamide is an old small molecule. Any original composition-of-matter patents associated with its discovery and commercialization expired decades ago. The product is therefore open to generic competition from an intellectual-property standpoint.

Formulation patents

No commercially important extended-release, controlled-release, abuse-deterrent, or delivery-system patent is associated with the current Diabinese franchise. The product was sold primarily as an immediate-release oral tablet.

Method-of-use patents

No active method-of-use patent is known to create meaningful exclusivity for chlorpropamide in type 2 diabetes. The original indication is established medical use, and the product does not have a modern patented combination, biomarker-selected population, or device-linked indication.

Manufacturing and process protection

Manufacturing know-how may still exist as confidential information, but it does not create meaningful market protection for an old generic small molecule. Chlorpropamide synthesis is not generally viewed as a manufacturing bottleneck comparable with complex biologics, sterile injectables, or highly specialized active pharmaceutical ingredients.

What is the FDA regulatory status of Diabinese?

Diabinese is a legacy FDA-approved product that is no longer a significant U.S. commercial therapy. FDA labeling identifies chlorpropamide’s prolonged hypoglycemic effect and risks in patients with impaired renal function and in older adults [1].

The product’s regulatory decline reflects clinical substitution rather than a new regulatory exclusivity cycle. Modern diabetes guidelines place greater emphasis on therapies with cardiovascular, renal, weight, or hypoglycemia advantages. Sulfonylureas remain available as low-cost glucose-lowering agents, but chlorpropamide is rarely selected because its risk profile is less favorable than that of later alternatives [3].

The FDA’s discontinued-product records should not be interpreted automatically as a finding that the product was withdrawn for safety or lack of effectiveness. Discontinuation can reflect commercial decisions, declining demand, manufacturing economics, or portfolio rationalization.

How did Diabinese compare with competing diabetes drugs?

Diabinese competed first with other sulfonylureas and later with therapies that offered better dosing flexibility and safety characteristics.

Drug or class	Position relative to chlorpropamide
Tolbutamide	Earlier first-generation sulfonylurea with shorter action
Glibenclamide/glyburide	Second-generation sulfonylurea with continued hypoglycemia risk
Glipizide	Shorter-acting sulfonylurea, generally more manageable in older patients
Glimepiride	Later sulfonylurea with broad generic availability
Metformin	Became the dominant low-cost foundational oral therapy
DPP-4 inhibitors	Lower hypoglycemia risk but higher cost
SGLT2 inhibitors	Added cardiovascular and renal outcome benefits
GLP-1 receptor agonists	Added weight and cardiometabolic benefits
Insulin	Remained necessary for advanced beta-cell failure

Metformin’s cost, efficacy, and established safety profile materially reduced the role of first-generation sulfonylureas. Later agents further weakened Diabinese by providing treatment benefits beyond glucose reduction.

The American Diabetes Association continues to recognize sulfonylureas as glucose-lowering agents but identifies hypoglycemia and weight gain as important limitations. Current treatment selection is increasingly driven by cardiovascular disease, heart failure, chronic kidney disease, obesity, and patient-specific risk factors [3].

What is the financial trajectory of Diabinese?

Diabinese followed a conventional mature-drug decline:

1. Initial expansion: The product benefited from limited competition when oral pharmacologic options for type 2 diabetes were narrow.
2. Patent erosion: Generic competition reduced pricing power after the original exclusivity period ended.
3. Therapeutic substitution: Metformin and later sulfonylureas displaced chlorpropamide in routine practice.
4. Risk-driven contraction: Prolonged hypoglycemia and renal-clearance concerns reduced use among older and medically complex patients.
5. Commercial exit: Low demand and limited strategic value reduced the incentive to maintain branded distribution.

Pfizer does not report Diabinese as a standalone revenue line in its public financial statements. The product’s current revenue contribution is therefore not separately quantifiable from company filings and is not material to Pfizer’s consolidated financial performance.

Revenue exposure assessment

Financial factor	Assessment
Current branded revenue	No material U.S. revenue identified
Pricing power	None
Generic substitution risk	Complete and longstanding
Reimbursement leverage	Minimal
Sales-force value	None
Manufacturing scale	Low
Portfolio strategic value	Negligible
Litigation-driven revenue risk	Negligible
Investor relevance	Historical rather than current

For an acquirer, licensing party, or generic manufacturer, the principal risk is not patent infringement. It is insufficient demand, limited distribution, low reimbursement value, and the possibility that pharmacies and wholesalers will not maintain inventory.

Which companies are challenging or competing with Diabinese?

No company has a meaningful current branded challenge strategy against Diabinese. The competitive field is composed of generic sulfonylurea manufacturers and diabetes companies selling newer therapies.

Potential generic competition historically included manufacturers of chlorpropamide tablets. Those products have not generated a commercially significant market comparable with generic metformin, glipizide, or glimepiride. The absence of a large active market reduces the incentive for manufacturers to launch or maintain chlorpropamide supply.

Current competitive pressure comes primarily from:

• Generic metformin manufacturers.
• Generic glipizide and glimepiride manufacturers.
• Manufacturers of DPP-4 inhibitors.
• SGLT2 inhibitor companies, including AstraZeneca, Boehringer Ingelheim, Eli Lilly, and Johnson & Johnson.
• GLP-1 receptor agonist companies, including Novo Nordisk and Eli Lilly.

These therapies compete for the same type 2 diabetes treatment budget but offer clinical attributes that chlorpropamide cannot match, especially for cardiovascular, renal, and weight-management outcomes.

What generic launch risks exist for chlorpropamide?

A new generic launch would face modest legal risk but substantial commercial risk.

Legal and regulatory risks

The likely legal pathway is straightforward because:

• Original patent protection has expired.
• No meaningful Orange Book patent barrier is apparent.
• Paragraph IV litigation exposure is low.
• No biosimilar pathway applies because chlorpropamide is a small molecule.
• FDA approval would still require pharmaceutical equivalence and bioequivalence.

Commercial risks

The commercial barriers are more significant:

• Very small prescriber demand.
• Limited clinical use in treatment guidelines.
• Safety concerns involving prolonged hypoglycemia.
• Low expected unit volume.
• Potential difficulty securing reliable active-ingredient supply.
• Limited wholesaler and pharmacy stocking.
• Generic price competition if multiple suppliers enter.

A manufacturer could obtain regulatory approval yet fail to achieve an economically attractive launch. The product’s low patent risk does not translate into high market opportunity.

What is the geographic coverage of Diabinese?

The historical brand was associated primarily with the U.S. market and Pfizer’s international commercial operations. Current availability is likely jurisdiction-specific and may depend on local registrations, manufacturer decisions, and national reimbursement systems.

No broad, active global commercial franchise is evident. In regulated markets where chlorpropamide remains listed in historical databases, listing does not establish meaningful supply or routine clinical use.

The product’s geographic decline follows the same pattern as its U.S. decline: older oral therapy displaced by metformin and newer agents, with additional pressure from safety and treatment-guideline changes.

What patent litigation or settlement agreements affect Diabinese?

No current patent litigation or settlement agreement materially affects Diabinese. There is no active branded patent campaign, authorized-generic strategy, or settlement structure comparable with those associated with high-revenue medicines.

The historical commercial outcome was determined by ordinary patent expiration and therapeutic substitution rather than a recent Paragraph IV settlement.

How strong is the Diabinese patent estate?

The current patent estate is effectively exhausted.

Patent-estate category	Current strength
Composition of matter	None remaining
Core formulation	None materially identified
Method of use	None materially identified
Pediatric exclusivity	Expired or unavailable
New chemical entity exclusivity	Expired
Manufacturing process	No meaningful market barrier
Orange Book position	No material active protection
Litigation leverage	Very low

Diabinese has no meaningful defensible intellectual-property moat. Its remaining value is limited to historical brand recognition, regulatory records, and any residual know-how associated with manufacturing or distribution.

Key Takeaways

• Diabinese is chlorpropamide, a first-generation sulfonylurea approved in the United States in 1958.
• Its commercial decline resulted from patent expiration, generic substitution, safety limitations, and competition from metformin and newer diabetes therapies.
• No active U.S. patent estate or meaningful Orange Book protection supports the brand.
• No current Paragraph IV litigation, biosimilar risk, or relevant settlement agreement materially affects the product.
• Pfizer does not publicly disclose standalone Diabinese revenue.
• Current U.S. commercial revenue is not material.
• A new generic launch would face low IP risk but weak demand, limited distribution, and unfavorable market economics.
• The product has historical pharmaceutical significance but negligible current strategic or financial value.

FAQs

Is Diabinese still available by prescription?

Diabinese is not a meaningful current U.S. commercial product. Historical FDA records and labeling may remain accessible even when routine commercial supply has ended.

Is chlorpropamide cheaper than metformin?

A legacy generic product could have a low unit price, but limited availability and pharmacy stocking can make actual access less predictable than for widely supplied metformin.

Can a generic company launch chlorpropamide without a patent license?

Because the original patent estate expired decades ago, a current generic applicant would not generally need a license to the historical Diabinese brand patents. FDA approval and manufacturing compliance would still be required.

Why was chlorpropamide replaced by newer sulfonylureas?

Chlorpropamide has a long duration of action and can cause prolonged hypoglycemia. Later sulfonylureas offered more manageable dosing and pharmacologic profiles, while metformin and newer agents offered broader clinical advantages.

Does Diabinese have any biosimilar competition?

No. Biosimilars apply to biological products. Chlorpropamide is a conventional chemically synthesized small molecule, so any competition follows the generic-drug pathway rather than the biosimilar pathway.

References

1. U.S. Food and Drug Administration. (2009). Diabinese (chlorpropamide) tablets: Prescribing information. FDA.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th edition. FDA.
3. American Diabetes Association Professional Practice Committee. (2024). 9. Pharmacologic approaches to glycemic treatment: Standards of care in diabetes-2024. Diabetes Care, 47(Supplement 1), S158-S178. https://doi.org/10.2337/dc24-S009
4. U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs database. FDA.
5. National Library of Medicine. (n.d.). DailyMed: Diabinese and chlorpropamide drug labeling. U.S. National Library of Medicine.