List of Excipients in Branded Drug AVYCAZ

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Allergan Inc	AVYCAZ	ceftazidime, avibactam	0456-2700	SODIUM CARBONATE	2032-06-15

Last updated: August 15, 2026

ecutive summary: AVYCAZ is an intravenous fixed-dose combination of ceftazidime and avibactam supplied as a sterile powder in a single-dose vial. Its excipient platform is deliberately narrow: arginine supports formulation and reconstitution performance, while the product relies on aseptic manufacturing, validated lyophilized-powder stability, and controlled dilution rather than a complex delivery system. The strongest commercial opportunities are generic sterile powder, ready-to-use or ready-to-administer presentations, hospital workflow products, and excipient or container systems that improve stability and reduce preparation errors. The principal barriers are combination-product equivalence, beta-lactam manufacturing controls, avibactam supply, stability validation, and regulatory requirements for intravenous dosage-form comparability.

AVYCAZ Excipient Strategy, Formulation Patents, Generic Risk, and Commercial Opportunities

What is AVYCAZ and how is it formulated?

AVYCAZ contains ceftazidime and avibactam in a fixed 4:1 dose ratio. The approved vial contains 2 grams of ceftazidime and 0.5 grams of avibactam, supplied as a sterile powder for intravenous infusion.[1]

Attribute	AVYCAZ specification
Active ingredients	Ceftazidime and avibactam
Strength per vial	2 g ceftazidime plus 0.5 g avibactam
Dosage form	Sterile powder for intravenous infusion
Primary excipient	Arginine
Reconstitution	Sterile water for injection
Dilution	Compatible intravenous infusion solution under label conditions
Administration	Intravenous infusion over two hours
Therapeutic area	Serious Gram-negative bacterial infections
U.S. NDA	206494
U.S. commercial holder	Pfizer
FDA pathway	New drug application, not a biologic license application

The product is not a liposomal, depot, sustained-release, or device-assisted formulation. Its commercial value depends on intravenous delivery, broad hospital use, and the activity of avibactam against selected beta-lactamases rather than on a differentiated delivery vehicle.

The label identifies arginine as an inactive ingredient. Arginine is used in the formulation to support pH control and the chemical environment required for the ceftazidime-avibactam powder. The absence of a large excipient system reduces formulation complexity but increases the importance of pH, moisture, reconstitution time, container closure, and aseptic processing controls.[1]

What excipients are used in AVYCAZ?

The principal disclosed excipient is arginine. The active ingredients are present as ceftazidime pentahydrate and avibactam sodium. The formulation is supplied in a single-dose vial as a sterile powder.[1]

Why is arginine commercially important?

Arginine can contribute to:

• pH adjustment and buffering capacity;
• improved chemical stability of beta-lactam antibiotics;
• powder formation and cake structure;
• reconstitution behavior;
• control of solution properties after dilution.

For a generic manufacturer, the challenge is not simply to reproduce the nominal arginine quantity. The applicant must demonstrate that the excipient level, pH, residual moisture, reconstitution profile, particulate burden, and impurity profile remain within acceptable limits through the labeled shelf life.

An excipient substitution may be technically possible, but it creates regulatory and development risk. A different buffer, amino acid, or bulking agent could alter degradation pathways, osmolality, solution clarity, infusion compatibility, or the relative stability of the two active ingredients.

What formulation and manufacturing attributes are protected by AVYCAZ?

The commercially relevant formulation protection is likely to center on the combination of:

1. Ceftazidime and avibactam in a fixed ratio.
2. A sterile powder presentation.
3. The selected excipient environment.
4. Reconstitution and dilution conditions.
5. Stability of both active ingredients in the same vial.
6. Container-closure and moisture-control performance.
7. Manufacturing processes that preserve potency and limit degradation.

The public FDA label establishes the composition and administration requirements, but it does not by itself establish the scope of any formulation patent. A complete freedom-to-operate review must examine issued patents, pending applications, terminal disclaimers, continuations, reexaminations, and litigation records in the relevant jurisdictions.

A key distinction applies to excipient strategy: an excipient may be commercially important without being independently patent-protected. Patent claims may instead be directed to the active combination, a salt or crystal form, a stabilized composition, a method of treating resistant infections, or a manufacturing process.

When does AVYCAZ lose exclusivity?

AVYCAZ does not have biosimilar exclusivity issues because it is a chemically defined small-molecule antibacterial product, not a biologic. Generic competition would proceed through an abbreviated new drug application rather than a biosimilar application.

FDA approval of a generic AVYCAZ-equivalent product depends on the applicable statutory exclusivity and patent framework. The relevant protections can include:

Protection	Relevance to AVYCAZ
New chemical entity exclusivity	Potentially relevant at original approval, subject to the status of each active ingredient and the combination
Five-year NCE exclusivity	Blocks standard ANDA filing during the exclusivity period, subject to Paragraph IV rules
Three-year clinical-investigation exclusivity	May apply to certain new uses or changes supported by required clinical studies
Patent protection	May cover the active combination, formulation, use, salt, crystal form, or manufacturing process
Pediatric exclusivity	Could add six months if awarded
Orphan exclusivity	Generally disease- and indication-specific and not the principal commercial framework for AVYCAZ

The precise loss-of-exclusivity date cannot be inferred from the product label alone. It requires a contemporaneous review of FDA Orange Book listings, patent certifications, court decisions, and any pediatric or statutory exclusivity periods.

What is the Orange Book status of AVYCAZ?

AVYCAZ is an FDA-approved prescription drug subject to the Orange Book framework for approved drug products and listed patents. Orange Book status is commercially important because an ANDA applicant must address listed patents through Paragraph I, II, III, or IV certification, or a section VIII statement for certain method-of-use patents.

The practical issues for a generic applicant are:

• whether AVYCAZ patents are currently listed;
• whether listed patents cover the composition, formulation, method of use, or manufacturing process;
• whether the proposed label overlaps patented indications;
• whether a Paragraph IV certification would trigger litigation;
• whether any listed patent is expired, delisted, or subject to a terminal disclaimer.

A generic product that omits a patented method-of-use indication may reduce litigation exposure if the remaining label is legally and regulatorily adequate. That strategy is more difficult for an antibacterial product where the approved indication, pathogen coverage, and dosing language are closely linked.

Which companies are challenging AVYCAZ?

No company-specific Paragraph IV challenge or settlement should be inferred from FDA labeling materials. The relevant competitive field includes generic injectable manufacturers with:

• ceftazidime manufacturing capability;
• avibactam sourcing or internal synthesis capability;
• sterile powder filling capacity;
• beta-lactam containment infrastructure;
• hospital contracting relationships;
• regulatory experience with complex injectable ANDAs.

Potential competitors are more likely to emerge from established injectable manufacturers than from conventional oral-generic companies. Avibactam adds a second active ingredient with separate impurity, analytical, supply, and stability requirements. That reduces the number of practical entrants compared with a simple ceftazidime generic.

What generic entry risks exist for AVYCAZ?

Generic entry risk is moderate to high from a technical perspective but depends heavily on the remaining patent estate.

Technical barriers

A generic applicant must control:

• equivalent ceftazidime-avibactam ratio;
• sterility and endotoxin levels;
• powder uniformity;
• residual moisture;
• reconstitution time;
• solution clarity and visible particles;
• degradation products;
• container-closure integrity;
• compatibility with infusion solutions;
• stability after reconstitution and dilution.

The applicant also must validate an aseptic process appropriate for a beta-lactam product. Dedicated or segregated facilities may be needed to control cross-contamination and occupational exposure.

Commercial barriers

Hospitals may favor products with:

• ready-to-use packaging;
• fewer preparation steps;
• extended in-use stability;
• barcoded unit-dose presentation;
• compatible premixed infusion bags;
• reliable shortage performance;
• competitive contract pricing.

A lower-cost vial may not displace the branded product if pharmacy labor, preparation waste, inventory complexity, or antimicrobial stewardship requirements offset the acquisition-price advantage.

What commercial opportunities exist for AVYCAZ excipients and delivery systems?

Ready-to-use and ready-to-administer products

The highest-value opportunity is a presentation that reduces pharmacy compounding. A validated premixed bag or extended-stability liquid could reduce reconstitution steps and preparation errors. The principal challenge is maintaining stability of both ceftazidime and avibactam in solution.

A ready-to-use product would require evidence for:

• container compatibility;
• adsorption and extractables;
• solution stability;
• light exposure;
• refrigerated and controlled-room-temperature storage;
• shipping excursions;
• microbial integrity;
• infusion-device compatibility.

Improved single-dose vials

A lower-risk opportunity is an optimized powder vial using the existing excipient concept. Improvements could include:

• more robust cake structure;
• faster reconstitution;
• reduced foaming;
• lower residual moisture;
• improved vial fill accuracy;
• smaller packaging footprint;
• better moisture-barrier closures.

These changes may support differentiated trade dress or formulation claims, although they would not necessarily create strong patent exclusivity.

Excipient and container-closure supply

Specialty suppliers can target:

• pharmaceutical-grade arginine;
• low-endotoxin excipients;
• elastomeric closures with low extractables;
• high-barrier glass vials;
• ready-to-use infusion containers;
• sterile transfer devices;
• closed-system reconstitution components.

The strongest value proposition is supply reliability and validated performance, not merely substitution of one compendial excipient for another.

Hospital workflow products

A co-pack containing the vial, diluent, transfer device, and administration accessories could create value without changing the active formulation. Such a product may improve medication-use safety and reduce pharmacy handling. Its regulatory classification and labeling would depend on whether the package is marketed as a drug presentation, convenience kit, or combination product.

How does AVYCAZ compare with other resistant Gram-negative antibiotics?

Product	Active ingredients	Dosage form	Excipient opportunity	Competitive distinction
AVYCAZ	Ceftazidime-avibactam	IV sterile powder	Arginine-based powder, premix, reconstitution systems	Avibactam-enabled beta-lactamase coverage
Vabomere	Meropenem-vaborbactam	IV powder	Powder stability and ready-to-use formats	Carbapenem plus boronic acid beta-lactamase inhibitor
Zerbaxa	Ceftolozane-tazobactam	IV powder	Sterile powder and hospital preparation systems	Different cephalosporin-beta-lactamase inhibitor combination
Fetroja	Cefiderocol	IV powder	Powder, dilution, and infusion compatibility	Siderophore cephalosporin mechanism

AVYCAZ has a relatively simple excipient profile compared with complex biologic or controlled-release products. Its differentiation risk is therefore greater if generic manufacturers can reproduce the sterile powder economically.

What patent litigation and settlement issues affect AVYCAZ?

The principal litigation triggers would be:

• a Paragraph IV certification against an Orange Book-listed patent;
• claims directed to the ceftazidime-avibactam combination;
• formulation claims covering arginine or another stabilizing system;
• method-of-use claims covering resistant pathogens;
• process claims involving avibactam manufacture or purification;
• infringement allegations based on a generic label.

Settlement terms could include a delayed generic launch, a license for specific indications, or a covenant not to sue. Without a verified docket and current Orange Book record, no specific active case, settlement date, or launch date should be treated as established.

What is the revenue exposure and investment case?

Pfizer does not generally report AVYCAZ as a separately disclosed product-level revenue line in its consolidated public reporting. Revenue exposure therefore must be assessed through the broader hospital and established-products portfolio rather than a standalone AVYCAZ figure.[4]

Commercial value is supported by:

• serious hospital infections;
• limited treatment alternatives for resistant Gram-negative pathogens;
• infectious-disease specialist use;
• high clinical and stewardship value in targeted patients;
• technical barriers to avibactam-containing generic production.

Downside risk comes from:

• generic sterile injectable entry;
• hospital purchasing pressure;
• antimicrobial stewardship restrictions;
• competing beta-lactamase inhibitor combinations;
• manufacturing shortages;
• lack of a differentiated delivery platform.

Key takeaways

• AVYCAZ uses a narrow excipient platform centered on arginine and a sterile powder presentation.
• The main formulation challenge is preserving the stability and reconstitution performance of two active ingredients in one vial.
• Ready-to-use bags, improved vials, closed-system transfer devices, and validated container-closure systems are the clearest commercial opportunities.
• Generic entry requires more than active-ingredient equivalence. Sterility, moisture, impurity control, reconstitution, dilution, and beta-lactam facility controls are material barriers.
• AVYCAZ is not subject to biosimilar competition.
• The precise patent expiration, Orange Book, Paragraph IV, litigation, and settlement position requires a current patent and FDA-record review.
• Pfizer does not provide a standalone public AVYCAZ revenue figure in its consolidated reporting.

FAQs

Can arginine be replaced in a generic AVYCAZ formulation?

Potentially, but substitution would require formulation, stability, compatibility, and regulatory support. A replacement buffer or amino acid could change pH, degradation, reconstitution, osmolality, and impurity formation.

Is AVYCAZ a lyophilized drug?

AVYCAZ is supplied as a sterile powder for intravenous infusion. Commercial descriptions may refer to it as a powder or lyophilized powder, but the legally controlling description is the FDA-approved dosage-form and manufacturing documentation.

Could a generic AVYCAZ be sold as a premixed infusion bag?

Potentially. A premixed presentation would require demonstration of chemical, physical, microbiological, container, and infusion-device compatibility over the proposed shelf life.

Does AVYCAZ have an excipient patent?

The presence of arginine in the FDA label does not establish an active excipient patent. Any determination would require review of issued and pending patent claims covering the composition, formulation, process, or use.

Which excipient suppliers are best positioned for AVYCAZ-related opportunities?

Suppliers with pharmaceutical-grade arginine, low-endotoxin control, sterile manufacturing support, high-barrier vial systems, elastomeric closures, and validated infusion containers are best positioned. Product-specific qualification remains necessary for beta-lactam injectable use.

References

1. U.S. Food and Drug Administration. (2023). AVYCAZ (ceftazidime and avibactam) for injection: Prescribing information.
2. U.S. Food and Drug Administration. (2015). FDA approves new antibacterial drug Avycaz to treat complicated intra-abdominal and urinary tract infections.
3. National Library of Medicine. (2024). DailyMed: AVYCAZ, ceftazidime and avibactam injection, powder, for solution.
4. Pfizer Inc. (2024). Annual report and Form 10-K.
5. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book.