List of Excipients in Branded Drug GLIPIZIDE AND METFORMIN HCL

Generic Drugs Containing GLIPIZIDE AND METFORMIN HCL

Company	Ingredient	NDC	Excipient
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	glipizide and metformin hcl	23155-115	FERRIC OXIDE RED
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	glipizide and metformin hcl	23155-115	HYPROMELLOSE 2910
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	glipizide and metformin hcl	23155-115	MAGNESIUM STEARATE
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	glipizide and metformin hcl	23155-115	POLYETHYLENE GLYCOL 6000
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	glipizide and metformin hcl	23155-115	POVIDONE

What are the Most Frequently-Used Excipients in GLIPIZIDE AND METFORMIN HCL?

# Of NDCs	Excipient
5	FERRIC OXIDE RED
6	HYPROMELLOSE 2910
6	MAGNESIUM STEARATE
6	POLYETHYLENE GLYCOL 6000
6	POVIDONE

Glipizide and Metformin HCl Excipient Strategy and Commercial Opportunities

Last updated: August 20, 2026

Glipizide/metformin hydrochloride is an established immediate-release fixed-dose combination for type 2 diabetes. Its commercial value lies in low-cost generic manufacturing, adherence-oriented packaging, regional formulation differentiation, and supply-chain efficiency rather than new chemical-entity exclusivity. The principal technical challenge is combining a low-dose, poorly soluble sulfonylurea with a high-dose, highly soluble but gastrointestinally difficult biguanide in one tablet.

The U.S. reference product, Metaglip, was approved by the FDA as a combination of glipizide and metformin hydrochloride. Current commercial products are primarily generic immediate-release tablets. The product has no meaningful remaining regulatory exclusivity in the United States, and commercial entry depends on abbreviated new drug application approval, bioequivalence, manufacturing cost, and market access rather than patent licensing. [1,2]

What excipient strategy is appropriate for glipizide and metformin HCl tablets?

A robust formulation should control three variables: metformin tablet size, glipizide content uniformity, and rapid but reproducible dissolution of both active ingredients.

Formulation requirement	Technical issue	Preferred excipient strategy
Glipizide dose uniformity	Glipizide is present at a low dose relative to metformin	Pre-dilution with microcrystalline cellulose or lactose; high-shear wet granulation; validated blend uniformity
Metformin loading	Metformin HCl can account for most tablet mass	Direct compression with high-functionality filler or wet granulation with controlled binder addition
Dissolution	Glipizide has low aqueous solubility; metformin dissolves readily	Disintegrant and wetting-agent optimization without creating excessive tablet hardness
Gastrointestinal tolerability	Metformin commonly causes nausea, diarrhea, and abdominal discomfort	Administration with meals; avoid unnecessary high-dose immediate-release exposure; use low friability and rapid disintegration
Chemical stability	Both actives require protection from humidity and process variability	Low-moisture excipients, controlled granulation endpoint, moisture-barrier packaging
Scale-up	Large metformin load can produce segregation and compression defects	Granulation or engineered direct-compression grades; controlled particle-size distribution

Which fillers and binders are commercially suitable?

Microcrystalline cellulose is a strong primary filler because it improves compactibility and supports direct compression. It is especially useful when the formulation must accommodate a relatively large metformin HCl load without excessive tablet weight.

Lactose can improve blend dilution and tabletability, but its use requires compatibility and moisture assessment. Anhydrous lactose is often preferable where moisture control is important. Lactose monohydrate may be acceptable when the manufacturing process has adequate control of water exposure.

Povidone is a conventional binder for wet granulation. Hypromellose can provide binding capacity but may slow disintegration if used at excessive levels. Low-substituted hydroxypropyl cellulose is another option when disintegration and compactibility must be balanced.

Which disintegrants and lubricants should be evaluated?

Croscarmellose sodium, sodium starch glycolate, and crospovidone are the main disintegrant candidates. Crospovidone can provide rapid wicking and is useful where high metformin loading increases tablet density. Croscarmellose sodium can provide strong swelling but may produce variable performance if the tablet is over-compressed.

Magnesium stearate is the standard lubricant, but excessive concentration or over-lubrication can reduce tablet hardness and delay dissolution. Sodium stearyl fumarate is an alternative when dissolution sensitivity to magnesium stearate is identified.

Colloidal silicon dioxide can improve flow in direct-compression systems. Its level should remain low enough to avoid adverse effects on blend uniformity and tablet ejection.

What formulation architecture best supports glipizide/metformin HCl?

The preferred commercial architecture is usually a single-layer immediate-release tablet manufactured by wet granulation or engineered direct compression.

Single-layer immediate-release tablet

A single-layer tablet offers the lowest manufacturing cost, the simplest regulatory package, and the broadest generic-market applicability. It is suitable for strengths such as:

• Glipizide 2.5 mg/metformin HCl 250 mg
• Glipizide 2.5 mg/metformin HCl 500 mg
• Glipizide 5 mg/metformin HCl 500 mg

The principal risk is segregation because glipizide represents a small fraction of total tablet mass. Separate granulation of glipizide with a portion of the filler can improve content uniformity before blending with the metformin granulation.

Bilayer tablet

A bilayer design can physically separate glipizide and metformin and permit independent optimization of each layer. It can also support differentiated release profiles. The disadvantages are higher equipment cost, more complex process validation, greater risk of layer-weight variation, and a less attractive cost structure for a mature generic product.

A bilayer tablet becomes more commercially relevant when the sponsor is developing a modified-release product, pursuing a regional premium, or seeking a 505(b)(2) pathway based on a clinically differentiated release profile. It is generally less attractive for a standard immediate-release ANDA.

Modified-release combination

Metformin extended-release products are commercially established, but combining extended-release metformin with immediate-release glipizide requires careful pharmacokinetic and clinical justification. The product would need to demonstrate that the release profile does not produce excessive glipizide exposure or inadequate metformin control.

This approach could reduce dosing frequency and improve gastrointestinal tolerability, but it would involve greater formulation, clinical, and regulatory cost. It is a product-development opportunity rather than a straightforward generic substitution.

What excipients are listed in commercial glipizide/metformin products?

Inactive ingredients vary by manufacturer, strength, and jurisdiction. Representative U.S. labels for glipizide/metformin tablets identify excipient classes such as microcrystalline cellulose, povidone, croscarmellose sodium, colloidal silicon dioxide, magnesium stearate, and coating components where applicable. Product-specific DailyMed labeling must be used for the final composition because excipients are not uniform across suppliers. [3]

A practical target composition would typically contain:

Excipient class	Commercial purpose
Microcrystalline cellulose or anhydrous lactose	Filler and compression aid
Povidone or hydroxypropyl cellulose	Wet-granulation binder
Crospovidone, croscarmellose sodium, or sodium starch glycolate	Tablet disintegration
Colloidal silicon dioxide	Flow aid
Magnesium stearate or sodium stearyl fumarate	Lubrication
Hypromellose, titanium dioxide, and colorants	Film coating, identification, and light protection
Polyethylene glycol	Coating plasticizer

The strategy should minimize the number of excipients while preserving dissolution, content uniformity, tablet integrity, and acceptable swallowability.

What manufacturing and intellectual-property barriers exist?

The active ingredients are off-patent small molecules. The primary barriers are operational and regulatory.

Content uniformity

Glipizide is present at a much lower dose than metformin. Poor segregation control can cause out-of-specification assay or content-uniformity results. The strongest process controls are:

1. Narrow particle-size distributions for both actives.
2. Pre-blending or granulating glipizide with a carrier.
3. Controlled transfer distances and hopper residence time.
4. In-process blend and tablet testing.
5. Packaging and handling controls that prevent segregation after compression.

Metformin loading and tablet size

Metformin HCl has a high dose burden. A standard tablet can become large, hard to swallow, and commercially unattractive. High-density grades, optimized granulation, and higher tabletability fillers can reduce tablet volume.

A smaller tablet can provide a market advantage in jurisdictions where swallowing difficulty affects adherence, but size reduction cannot compromise dissolution or mechanical strength.

Humidity and packaging

Metformin formulations can be sensitive to process moisture and storage conditions. Blister packaging with a high moisture barrier or high-density polyethylene bottles with appropriate closure systems should be evaluated. Stability studies should track assay, degradation products, dissolution, hardness, friability, and appearance.

Patent barriers

The original combination-product patents and regulatory exclusivity periods are expired or no longer commercially material. No active-ingredient patent barrier is expected to prevent conventional U.S. generic development. Patent risk is more likely to arise from a later-developed modified-release profile, coating system, manufacturing process, or combination regimen than from the core immediate-release tablet.

What is the FDA regulatory status and Orange Book position?

Metaglip was approved under NDA 021178 as an oral combination product containing glipizide and metformin hydrochloride. The FDA Orange Book is the controlling source for current reference-product, therapeutic-equivalence, patent-listing, and exclusivity information. [1]

For a conventional immediate-release generic, the expected pathway is an ANDA demonstrating pharmaceutical equivalence and bioequivalence to the reference listed drug. Key requirements include:

• Same active ingredients and dosage form.
• Same strength or strengths.
• Equivalent route of administration.
• Comparative dissolution.
• Fed and fasting bioequivalence where required.
• Manufacturing controls suitable for commercial-scale production.
• Labeling consistent with the reference product, subject to permitted differences.

A sponsor seeking a materially different release profile, dosage regimen, or clinical use may require a 505(b)(2) application rather than an ANDA. FDA guidance on ANDA bioequivalence and product-specific recommendations should govern study design. [4,5]

When does glipizide/metformin lose exclusivity?

U.S. market exclusivity has already expired for the original immediate-release combination. The commercial product is therefore exposed to generic competition and price compression.

Exclusivity category	Status for conventional glipizide/metformin
New chemical entity exclusivity	Expired
Orphan exclusivity	Not applicable
Pediatric exclusivity	Not commercially material to current entry
Core composition patents	Expired or no longer blocking conventional entry
Formulation patents	Potentially relevant only to differentiated modified-release or delivery systems
Method-of-use patents	Limited practical value for a mature, widely established diabetes regimen
Biosimilar exclusivity	Not applicable

Are Paragraph IV challenges likely for glipizide/metformin?

Paragraph IV litigation risk is low for the conventional product because the original combination is mature and generic products have already entered the market. A new ANDA applicant would generally focus on whether any currently listed patent remains relevant to the reference product.

The more realistic legal risks relate to:

• A later-listed formulation patent.
• A modified-release combination.
• A proprietary manufacturing process.
• A patent covering a specific tablet architecture.
• A branded product with a newly developed indication or delivery system.

For a standard immediate-release tablet, the main launch risk is FDA review timing and commercial viability, not patent litigation.

What generic launch scenarios exist?

Low-cost high-volume generic

The sponsor uses a simple immediate-release formulation, limited strengths, contract manufacturing, and standard bottle packaging. This model competes on price and pharmacy availability. It is the lowest-risk development path but produces limited margins.

Authorized or branded generic

A manufacturer supplies a distributor, health system, or regional brand with consistent packaging and supply. This approach can improve contracting access and reduce direct retail price competition.

Adherence-focused product

The sponsor markets a smaller tablet, calendar blister, once-daily regimen where clinically appropriate, or coordinated diabetes pack. The opportunity depends on whether the dosage schedule and labeling support the claim. Packaging differentiation is less exposed to formulation patent risk than a new release system.

Regional product

In emerging markets, a locally manufactured product with reliable supply and a broad strength range can compete against separate glipizide and metformin prescriptions. Registration requirements, reference-product selection, and local bioequivalence standards vary by jurisdiction.

Modified-release product

A sustained-release metformin component with glipizide could command a higher price if it demonstrates lower gastrointestinal burden or improved dosing convenience. Development costs and regulatory risk are materially higher than for a standard generic.

How strong is the patent estate for glipizide/metformin?

The core patent estate is weak from a blocking perspective because both active ingredients and the original combination have been commercially established for decades.

Patent estate component	Relative strength	Commercial interpretation
Glipizide composition	Low	Mature generic active ingredient
Metformin HCl composition	Low	Mature generic active ingredient
Immediate-release combination	Low	Conventional formulation is readily substitutable
Modified-release combination	Moderate	Potentially protectable through formulation and pharmacokinetic claims
Tablet-size or compression process	Low to moderate	May support narrow process protection
Coating or moisture-barrier system	Low to moderate	Usually avoidable by alternative excipients or packaging
New indication or treatment regimen	Moderate	Depends on claim scope and enforceability

A sponsor should not rely on formulation patents alone to support a premium unless the product has a clinically relevant performance difference that is difficult to design around.

Which companies are challenging or competing with glipizide/metformin?

Competition comes primarily from generic manufacturers and from alternative diabetes therapies rather than from biosimilar developers.

Relevant competitor groups include:

• Manufacturers of generic glipizide/metformin tablets.
• Suppliers of separate glipizide and metformin tablets.
• Metformin immediate-release and extended-release products.
• Sulfonylurea combinations involving glyburide or glimepiride.
• DPP-4 inhibitors, SGLT2 inhibitors, GLP-1 receptor agonists, and insulin products.

Biosimilar risk is zero because glipizide and metformin are synthetic small molecules, not biologics. The principal substitution risk comes from therapeutic switching to newer diabetes medicines with stronger cardiovascular, renal, weight, or hypoglycemia positioning.

What commercial opportunities remain?

The largest opportunity is not molecule exclusivity. It is a cost-efficient, quality-consistent product that addresses practical prescribing and supply needs.

Opportunity assessment

Opportunity	Revenue potential	Investment need	Risk
U.S. standard generic	Low to moderate	Low	High price competition
Emerging-market generic	Moderate	Moderate	Registration and supply-chain variation
Smaller tablet	Moderate	Moderate	Must preserve bioequivalence and dissolution
Calendar blister packaging	Low to moderate	Low	Limited reimbursement premium
Modified-release combination	Moderate to high	High	Clinical and regulatory complexity
Contract manufacturing/private label	Moderate	Low to moderate	Customer concentration
Hospital and public-sector tenders	Moderate volume	Low	Margin pressure
Combination product with newer agent	High potential	High	New clinical and patent burden

Revenue exposure

The immediate-release market should be modeled as a mature generic category with declining unit prices and concentration among low-cost suppliers. Revenue depends on volume, channel access, manufacturing yield, and supply reliability.

A differentiated product may support higher gross margins, but the addressable population is constrained by current treatment guidelines and the declining use of sulfonylureas in patients who can access newer therapies. The product remains commercially relevant where affordability, availability, and established clinical use dominate treatment selection. [6]

How does glipizide/metformin compare with newer diabetes combinations?

Product type	Main advantage	Main limitation	Competitive effect
Glipizide/metformin IR	Low cost and established use	Hypoglycemia and gastrointestinal effects	Strong in price-sensitive markets
Metformin ER	Lower dosing frequency and better tolerability for some patients	Does not provide sulfonylurea effect	Direct substitution risk
Metformin plus DPP-4 inhibitor	Lower hypoglycemia risk	Higher price	Moderate to strong substitution
Metformin plus SGLT2 inhibitor	Cardiovascular and renal benefits in selected populations	Higher price and class-specific adverse effects	Strong in guideline-driven markets
Metformin plus GLP-1 receptor agonist	Weight and glycemic benefits	Injectable or high-cost oral options	Strong in premium segments
Metformin plus insulin	Potent glucose lowering	Hypoglycemia and administration burden	Relevant in advanced disease

What licensing deals and settlement agreements affect the product?

No licensing deal is required to commercialize a conventional glipizide/metformin generic where the relevant patents and exclusivities have expired. A commercial agreement may still be useful for:

• Regional distribution.
• Contract manufacturing.
• Private-label supply.
• Public-sector tenders.
• Technology transfer for high-density metformin granulation.
• Access to a differentiated modified-release platform.

Settlement agreements are unlikely to be central to a mature immediate-release launch. If a sponsor develops a new modified-release product, patent litigation and launch settlements could become relevant, but those issues would attach to the new formulation rather than the established combination.

Key Takeaways

• Glipizide/metformin HCl is an off-patent, immediate-release generic opportunity.
• The main formulation challenge is uniform distribution of low-dose glipizide within a high-dose metformin tablet.
• Microcrystalline cellulose, controlled granulation, crospovidone or croscarmellose sodium, and limited magnesium stearate are practical starting points.
• A single-layer tablet is usually the lowest-cost development strategy.
• Bilayer and modified-release products offer differentiation but require higher development and regulatory investment.
• U.S. Paragraph IV and biosimilar risks are limited for the conventional product.
• Commercial success depends on manufacturing cost, supply reliability, tablet size, packaging, and emerging-market access.
• The strongest premium opportunity is a clinically differentiated modified-release or adherence-oriented product, not a conventional immediate-release tablet.
• Newer diabetes therapies create substantial therapeutic substitution risk, especially in markets with broad reimbursement.

FAQs

Is glipizide/metformin HCl eligible for an ANDA?

A conventional immediate-release generic can generally use the ANDA pathway if it matches the reference product in active ingredients, strength, dosage form, route, and release characteristics and demonstrates bioequivalence.

What is the main excipient risk in a glipizide/metformin tablet?

The principal risk is blend segregation and inadequate glipizide content uniformity. Excessive lubricant can create a second risk by slowing dissolution.

Can a smaller glipizide/metformin tablet be patented?

A smaller tablet may be patentable only if it satisfies applicable novelty and non-obviousness standards. Tablet size alone is unlikely to provide durable protection without a technically unexpected result or novel formulation architecture.

Does glipizide/metformin have biosimilar competition?

No. Glipizide and metformin are synthetic small molecules. Competition comes from generic drugs and therapeutic alternatives, not biosimilars.

Is extended-release glipizide/metformin commercially attractive?

It can be attractive if it improves dosing convenience, tolerability, or pharmacokinetic performance. The opportunity carries higher formulation, clinical, bioequivalence, and regulatory costs than a standard immediate-release generic.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

2. U.S. Food and Drug Administration. (2002). Metaglip prescribing information: Glipizide and metformin hydrochloride tablets.

3. National Library of Medicine. (2024). DailyMed: Glipizide and metformin hydrochloride tablet labeling. https://dailymed.nlm.nih.gov/

4. U.S. Food and Drug Administration. (2024). ANDA submissions: Content and format. https://www.fda.gov/drugs/guidance-compliance-regulatory-information/guidances-drugs

5. U.S. Food and Drug Administration. (2024). Product-specific guidances for generic drug development. https://www.accessdata.fda.gov/scripts/cder/psg/

6. American Diabetes Association Professional Practice Committee. (2024). 9. Pharmacologic approaches to glycemic treatment: Standards of care in diabetes. Diabetes Care, 47(Supplement 1). https://doi.org/10.2337/dc24-S009