List of Excipients in Branded Drug SAXAGLIPTIN AND METFORMIN HYDROCHLORIDE

Generic Drugs Containing SAXAGLIPTIN AND METFORMIN HYDROCHLORIDE

Company	Ingredient	NDC	Excipient
DrReddys Laboratories Inc	saxagliptin and metformin hydrochloride	43598-620	CELLULOSE, MICROCRYSTALLINE
DrReddys Laboratories Inc	saxagliptin and metformin hydrochloride	43598-620	FERRIC OXIDE RED
DrReddys Laboratories Inc	saxagliptin and metformin hydrochloride	43598-620	FERRIC OXIDE YELLOW
DrReddys Laboratories Inc	saxagliptin and metformin hydrochloride	43598-620	FERROSOFERRIC OXIDE
DrReddys Laboratories Inc	saxagliptin and metformin hydrochloride	43598-620	HYDROCHLORIC ACID

What are the Most Frequently-Used Excipients in SAXAGLIPTIN AND METFORMIN HYDROCHLORIDE?

# Of NDCs	Excipient
1	CELLULOSE, MICROCRYSTALLINE
1	FERRIC OXIDE RED
1	FERRIC OXIDE YELLOW
1	FERROSOFERRIC OXIDE
1	HYDROCHLORIC ACID

Saxagliptin and Metformin Hydrochloride: Excipient Strategy, Patent Position and Commercial Opportunities

Last updated: August 14, 2026

Saxagliptin/metformin hydrochloride is a technically demanding fixed-dose combination because a low-dose, moisture-sensitive DPP-4 inhibitor must be combined with a high-load, high-dose metformin hydrochloride extended-release matrix. The strongest commercial opportunities are generic or differentiated extended-release tablets, lower-pill-burden presentations, improved gastrointestinal tolerability, and manufacturing platforms that reduce tablet size and improve content uniformity.

The reference product is AstraZeneca’s KOMBIGLYZE XR, an oral extended-release tablet containing saxagliptin and metformin hydrochloride. The product was approved by the U.S. Food and Drug Administration in 2010 for adults with type 2 diabetes as an adjunct to diet and exercise [1].

What is the formulation profile of saxagliptin and metformin hydrochloride?

KOMBIGLYZE XR combines saxagliptin, generally administered at 5 mg once daily, with metformin hydrochloride extended release at strengths including 500 mg, 1,000 mg, and 2,000 mg daily through available tablet configurations [1].

Attribute	Saxagliptin	Metformin hydrochloride
Therapeutic class	DPP-4 inhibitor	Biguanide antihyperglycemic
Typical daily dose in combination	5 mg	500-2,000 mg
Formulation challenge	Low-dose content uniformity and stability	High drug loading, poor flow, gastrointestinal tolerability
Release objective	Immediate systemic availability	Extended release
Key risk	Segregation and degradation	Dose dumping, tablet size, variable release
Commercial role	Differentiated active ingredient	Dominant mass of the dosage form

The formulation must deliver saxagliptin consistently while controlling metformin release over the dosing interval. A direct blend of both active ingredients creates risks involving blend segregation, nonuniform saxagliptin distribution, compression variability, and failure of extended-release specifications.

What excipients are used in KOMBIGLYZE XR?

FDA labeling identifies inactive ingredients that include povidone and magnesium stearate, together with film-coating components [1]. The precise excipient architecture of a generic product does not need to replicate the reference formulation. It must demonstrate pharmaceutical equivalence, bioequivalence, quality, and appropriate in vitro performance.

A commercially practical formulation can use the following excipient architecture:

Formulation function	Candidate excipients	Development objective
Extended-release matrix	Hypromellose, polyethylene oxide, hydroxypropyl cellulose	Control metformin diffusion and erosion
Binder	Povidone, copovidone, hydroxypropyl cellulose	Improve granule strength and tablet integrity
Diluent	Microcrystalline cellulose, silicified microcrystalline cellulose	Improve compactability and reduce tablet weight
Flow aid	Colloidal silicon dioxide	Improve flow and reduce segregation
Lubricant	Magnesium stearate, sodium stearyl fumarate	Support ejection without slowing dissolution excessively
Granulation aid	Water or hydroalcoholic solvent system	Improve granule uniformity
Film coat	Hypromellose or polyvinyl alcohol, polyethylene glycol, talc, titanium dioxide	Improve appearance, handling, protection and swallowability
Moisture-control component	Low-moisture excipient grades, protective packaging	Reduce saxagliptin degradation and metformin-related instability

The final selection depends on the manufacturing process. Direct compression may reduce cost but increases segregation and flow risks. High-shear wet granulation improves content uniformity and compressibility but introduces water, which can affect stability. Roller compaction avoids aqueous processing but can produce weaker granules and altered dissolution after milling.

How should the excipient strategy address saxagliptin stability?

Saxagliptin is present at a low dose relative to metformin. The central development problem is therefore not simply chemical stability. It is uniform distribution of a small quantity of active ingredient throughout a tablet containing a large mass of metformin.

A robust strategy uses:

1. Geometric dilution or ordered mixing. Saxagliptin should be preblended with a compatible carrier before incorporation into the metformin phase.
2. Controlled particle-size distribution. Large differences between saxagliptin and metformin particle size can cause segregation during transfer and compression.
3. Low-moisture excipient grades. Water activity and residual moisture should be controlled during granulation, storage and packaging.
4. Protective packaging. High-barrier aluminum-aluminum blisters or tightly controlled high-density polyethylene packaging can reduce moisture exposure.
5. Segregation testing. Blend uniformity should be evaluated after hopper discharge, transfer, tablet compression and packaging-line handling.

Povidone is useful as a binder, but excessive binder levels can reduce porosity and slow metformin release. Magnesium stearate can improve tablet ejection but may create hydrophobic dissolution effects if overmixed. Lubrication time and lubricant concentration require tight process control.

What formulations are protected by the main technical barriers?

The key technical barriers are formulation and process performance rather than the simple combination of two known active ingredients.

Extended-release matrix systems

Metformin hydrochloride is highly water soluble. A hydrophilic polymer matrix must prevent rapid tablet disintegration and control drug diffusion. Hypromellose is a common platform, but polymer viscosity grade, concentration, particle size and hydration behavior materially affect dissolution.

The primary design variables are:

• Polymer concentration and viscosity grade
• Tablet porosity and compression force
• Metformin particle size
• Granule density
• Tablet shape and dimensions
• Coating weight
• Dissolution medium and agitation sensitivity

A matrix that passes a single dissolution profile can still fail under altered pH, agitation or fed-state conditions. Development should therefore include discriminatory dissolution methods rather than relying only on a routine release test.

Bilayer or multilayer tablets

A bilayer tablet can separate the saxagliptin-containing layer from the metformin extended-release layer. This approach may improve segregation control and permit independent optimization of each active ingredient.

Its disadvantages include:

• Higher compression complexity
• Risk of layer adhesion failure
• More demanding weight and hardness controls
• Increased equipment and validation costs
• Potentially larger tablet dimensions

A bilayer design has commercial value when a conventional monolithic matrix cannot achieve content uniformity and release performance simultaneously.

Multiparticulate systems

Pellets, granules or mini-tablets could provide more flexible release control and reduce sensitivity to single-tablet matrix defects. They can also support sprinkle or capsule presentations. The trade-off is higher manufacturing complexity, more extensive process validation and a potentially higher cost of goods.

What FDA regulatory pathway applies to generic products?

A generic saxagliptin/metformin hydrochloride product would generally be developed under an Abbreviated New Drug Application, provided the applicant can establish pharmaceutical equivalence and bioequivalence to the relevant reference product [2].

The major regulatory workstreams are:

Regulatory issue	Relevance
Strength equivalence	Each approved strength may require separate justification
Dosage-form equivalence	Extended-release tablet characteristics must match the reference product
Bioequivalence	Pharmacokinetic studies must address fasting and fed conditions where required
Alcohol-dose-dumping risk	Extended-release performance must be assessed in alcohol-containing media
In vitro dissolution	Profiles should be discriminatory and comparable
Impurity control	Degradation products and process impurities require qualification
Manufacturing controls	Blend uniformity, granule density, compression and coating require validated control
Labeling	Renal contraindications, lactic acidosis warnings and hypoglycemia information must be addressed

Metformin labeling includes renal function restrictions and lactic acidosis warnings. Saxagliptin has dose considerations in renal impairment and drug-interaction considerations, including strong CYP3A4/5 inhibitors [1].

When does saxagliptin and metformin lose exclusivity?

Saxagliptin’s original U.S. new chemical entity exclusivity has expired. The commercial protection period for the combination has therefore shifted from basic regulatory exclusivity toward patent listings, formulation claims, method-of-use claims and generic litigation outcomes.

The relevant U.S. exclusivity sources are:

• FDA Orange Book patent listings
• FDA exclusivity records
• Public ANDA Paragraph IV notices
• Federal district-court litigation
• Settlement agreements and launch licenses
• Any pediatric exclusivity attached to listed patents

The Orange Book must be reviewed by strength and dosage form because listed patents and certification obligations can differ between saxagliptin products, metformin extended-release products and the fixed-dose combination [3].

What patents protect the combination?

The protection landscape historically has involved several claim categories:

1. Saxagliptin compound and pharmaceutical composition patents.
2. Extended-release metformin formulation patents.
3. Fixed-dose combination patents.
4. Method-of-use patents for treating type 2 diabetes.
5. Manufacturing and solid-dosage-form claims.
6. Crystalline, particle-size or excipient-specific claims, where applicable.

A generic applicant is most exposed when a patent claims the specific extended-release architecture or a method of administering saxagliptin with metformin. A formulation that uses a different polymer system, granulation process or tablet structure may reduce infringement risk, but it still requires a claim-by-claim analysis.

Which companies are challenging saxagliptin/metformin exclusivity?

Generic competition has focused on saxagliptin, saxagliptin/metformin extended release and related DPP-4 inhibitor products. The relevant competitive set includes large generic manufacturers, regional suppliers and contract-development organizations capable of extended-release oral solid-dose manufacturing.

Company-specific Paragraph IV activity, tentative approvals and settlement terms change over time. Current status should be determined from the FDA Orange Book, FDA approval databases, court dockets and public company filings rather than inferred from commercial availability alone [3,4].

A first-filer or licensed launch partner may obtain a material timing advantage if it resolves patent litigation before other applicants. The value of that position depends on whether the applicant has:

• A final approval rather than a tentative approval
• Approval for all commercially important strengths
• A reliable supply chain for saxagliptin API
• A scalable extended-release process
• A settlement-based launch date
• Sufficient manufacturing capacity at launch

What generic launch risks exist for saxagliptin/metformin?

The principal launch scenarios are:

Scenario	Commercial effect
Single approved generic after patent resolution	Rapid price erosion with possible temporary share concentration
Multiple simultaneous launches	Steep discounting and rapid substitution
Authorized generic or licensed launch	Lower legal risk but weaker gross margin
Strength-limited approval	Reduced formulary and pharmacy substitution potential
Delayed launch caused by dissolution or bioequivalence failure	Loss of first-mover advantage
Non-infringing formulation with later approval	Potentially durable entry after listed patent expiry

The most important technical launch risks are failure under fed-state bioequivalence, excessive variability in metformin exposure, dissolution mismatch, saxagliptin content-uniformity failures and tablet-size limitations.

How strong is the patent estate for the product?

The patent estate is strongest where claims cover a specific extended-release combination, a defined polymer matrix or a validated method of use with commercially important strengths. It is weaker where protection relies only on broad combination concepts involving two established active ingredients.

Patent strength should be scored across five dimensions:

Dimension	Strong position	Weak position
Claim scope	Covers composition, process and use	Covers narrow formulation detail
Remaining term	Multiple years after approval	Near-term expiration
Validity	Supported by robust prosecution history	Vulnerable written-description or obviousness issues
Design-around difficulty	Requires major process change	Easily replaced excipient system
Commercial relevance	Covers high-volume strengths	Covers limited or discontinued configurations

Excipient patents can support lifecycle management, but they rarely create durable protection by themselves unless they produce a clear, reproducible performance advantage and claim scope that is difficult to design around.

What commercial opportunities exist in excipient development?

The most attractive opportunity is a lower-weight, lower-cost extended-release platform that preserves bioequivalence while reducing manufacturing variability.

Lower tablet burden

Metformin contributes most of the tablet mass. Higher-strength tablets can reduce the number of daily units, but tablet size may become unacceptable. A high-density matrix using silicified microcrystalline cellulose, optimized granulation and controlled compression can improve portability and swallowing characteristics.

Gastrointestinal tolerability

Metformin-associated gastrointestinal effects remain a barrier to adherence. A smoother release profile may support tolerability, although the clinical benefit must be demonstrated and cannot be assumed from dissolution data alone.

Flexible manufacturing

A common platform that supports 500 mg, 1,000 mg and higher total daily doses can reduce development and manufacturing costs. The platform should maintain consistent matrix behavior as metformin loading changes.

Regional supply and licensing

Commercial opportunities exist for:

• Localized generic supply in markets with limited DPP-4 availability
• Technology licensing to manufacturers with metformin capacity but no saxagliptin platform
• Contract manufacturing of extended-release tablets
• Private-label supply for pharmacy and health-plan channels
• Alternate packaging for hot and humid climates
• Combination products positioned for adherence programs

Excipient supplier opportunity

Excipient suppliers can differentiate through low-moisture grades, controlled particle-size materials, high-density direct-compression excipients and polymers with reproducible hydration profiles. The commercial proposition must be supported by comparative dissolution, tabletability, stability and scale-up data.

How does saxagliptin/metformin compare with competing combinations?

Product class	Main advantage	Main commercial weakness
Saxagliptin/metformin XR	Established DPP-4 plus metformin combination	Mature market and patent-driven price pressure
Sitagliptin/metformin	Large clinical and commercial footprint	Strong generic competition
Linagliptin/metformin	Reduced renal dose-adjustment burden for linagliptin	Different clinical positioning and market competition
Dapagliflozin/metformin	SGLT2 cardiovascular and renal positioning	Higher safety-monitoring and reimbursement complexity
Empagliflozin/metformin	Strong cardiometabolic positioning	More complex clinical value proposition
GLP-1-based therapy plus metformin	Greater efficacy in many patients	Injectable or higher-cost oral options

Saxagliptin/metformin is most commercially defensible where the product offers dependable once-daily dosing, competitive price, strong supply continuity and a smaller adherence burden than separate tablets.

What manufacturing and intellectual-property barriers matter most?

The largest barriers are process reproducibility and regulatory evidence. A manufacturer must control:

• Saxagliptin dispersion through the metformin matrix
• Granule size and density
• Lubrication and compression conditions
• Extended-release dissolution across pH and agitation conditions
• Moisture exposure during processing
• Long-term stability in commercial packaging
• Scale-up from pilot batches to commercial production

The strongest lifecycle-management strategy combines a technically differentiated matrix with data showing improved robustness, manufacturability or patient usability. A new excipient alone is unlikely to support premium pricing without a measurable product advantage.

Key Takeaways

• Saxagliptin/metformin hydrochloride is a high-dose, extended-release fixed-dose combination with a difficult low-dose uniformity problem.
• The reference product is KOMBIGLYZE XR, approved by FDA in 2010.
• Hypromellose or related hydrophilic polymers, controlled binders, low-moisture excipients and protective packaging are central formulation tools.
• Bilayer and multiparticulate systems provide alternatives when a monolithic matrix cannot meet uniformity and dissolution requirements.
• Generic opportunity depends on ANDA strategy, bioequivalence performance, strength coverage, patent certifications and supply reliability.
• The main commercial opportunities are lower tablet burden, improved process robustness, flexible strength platforms, regional licensing and cost-efficient extended-release manufacturing.
• Excipient-based patent value is highest when the excipient system is linked to measurable dissolution, stability, manufacturing or adherence benefits.

FAQs

Can saxagliptin and metformin hydrochloride be formulated as an immediate-release tablet?

Yes, but the commercial reference product uses extended-release metformin. An immediate-release formulation would require a separate regulatory and clinical development strategy and would not automatically be therapeutically or pharmaceutically equivalent to KOMBIGLYZE XR.

Which excipient is most important for metformin extended release?

The hydrophilic matrix polymer is usually the most influential excipient because its viscosity, concentration and hydration behavior control metformin release. Manufacturing variables can be equally important at commercial scale.

Is a bilayer tablet commercially superior to a single-layer tablet?

Not automatically. A bilayer tablet can improve separation and independent control of the two actives, but it adds equipment, validation and mechanical-integrity risks. It is most valuable when a single-layer design cannot achieve uniformity and dissolution targets.

Does a different excipient composition avoid all patent risk?

No. Patent risk depends on the claims. A different excipient may avoid a narrow formulation claim but still fall within broader composition, process or method-of-use claims.

What is the most attractive contract-manufacturing opportunity?

The strongest opportunity is a validated extended-release platform that can produce multiple metformin strengths with consistent saxagliptin content uniformity, robust dissolution and low moisture exposure. Such a platform can support generic, private-label and regional licensing programs.

References

1. U.S. Food and Drug Administration. (2010). KOMBIGLYZE XR (saxagliptin and metformin hydrochloride extended-release) prescribing information.
2. U.S. Food and Drug Administration. (2013). Guidance for industry: Bioequivalence studies with pharmacokinetic endpoints for drugs submitted under an ANDA.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs database.
5. International Council for Harmonisation. (2009). ICH Q8(R2): Pharmaceutical development.