ZYFLO: Pharmaceutical manufacturers, suppliers, and wholesalers

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Applicant	Tradename	Generic Name	Dosage	NDA	NDA/ANDA	Supplier	Package Code	Package	Marketing Start
Chiesi	ZYFLO	zileuton	TABLET;ORAL	020471	NDA	Chiesi USA, Inc.	10122-901-12	120 TABLET in 1 BOTTLE (10122-901-12)	1996-12-06
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>NDA/ANDA	>Supplier	>Package Code	>Package	>Marketing Start

Last updated: June 3, 2026

Zyflo (zileuton) Suppliers: Who Manufactures and Supplies the Drug in the US and What Are the IP and Supply-Chain Constraints?

Zyflo (zileuton) is a branded prescription medicine. For US market supply, the supplier landscape is driven by (1) the approved NDA marketing authorization holder(s), (2) contract manufacturing organizations (CMOs) used to make the drug substance (API) and final tablets, and (3) any authorized generics or licensed supply channels that could shift procurement away from the brand holder over time.

This report maps the supplier picture to the core actionable buckets: marketing authorization, manufacturing/CMO sourcing, and IP barriers that shape who can compete.

Who is the FDA-approved supplier/marketing authorization holder for Zyflo (zileuton) tablets?

The FDA’s current approved “applicant” for a branded drug is the starting point for identifying the legal supplier in the US market supply chain. For Zyflo (zileuton), the marketing authorization is held by the product’s NDA holder listed in FDA systems (Orange Book for listed drugs). The NDA holder is the entity that controls manufacturing site approvals and distribution under FDA permissions.

Where to identify the current US legal supplier

FDA Orange Book (Listed Drugs) entry for Zyflo (zileuton): identifies the applicant and lists patents tied to exclusivity and/or listed drug protection.
FDA labeling (package insert) for Zyflo: identifies the NDA holder and sometimes the distributor.

Procurement implication: buying “Zyflo” in the US market generally flows through the NDA holder’s authorized distribution model, unless an authorized generic or other labeled supply channel is active.

Which companies manufacture Zyflo (zileuton) tablets as contract manufacturers or finished-dose manufacturers?

Supplier identification splits into API manufacturing and finished-dose manufacturing.

API (zileuton drug substance) manufacturers

API suppliers for branded products are often CMOs or integrated chemical manufacturing sites named through:

FDA Drug Master File (DMF) references linked to Orange Book chemistry, manufacturing, and controls (not always public by company at the level of detail procurement teams need).
Public patent assignments that disclose manufacturing routes and intermediates and can correlate to known API producers.
Inspectional and site information that appears in FDA data products tied to facility listings.

Finished-dose (tablets) manufacturers

Finished-dose tablet suppliers are typically:

The NDA holder’s internal manufacturing plants, or
Third-party CMOs that hold US FDA approvals for the specific dosage form and strength.

Procurement implication: the “supplier” procurement teams care about (to qualify supply and audit cGMP) is the manufacturing site, not the marketing brand. Without that, vendor qualification becomes a risk.

Which patents and Orange Book listings control who can supply Zyflo (zileuton) generics or authorized generics?

The competitive supply landscape depends on patent and exclusivity status. Orange Book listings for Zyflo (zileuton) can block or delay generic entry even if a product can be formulated.

What to check in Orange Book for Zyflo

Listed drug entry: applicant
Drug substance / drug product patents
Patent expiration dates
Exclusivity codes (if applicable)

Procurement implication: If patents or exclusivities are still active for a listed drug, procurement options narrow to brand supply and any authorized/licensed supply mechanisms.

When does Zyflo (zileuton) lose exclusivity, and how does that change the supplier pool?

Generic or authorized generic supply typically accelerates when:

Listed patents expire, and
Exclusivity periods end, and
Any Paragraph IV litigation is resolved or settles.

Procurement implication: supplier pool expansion usually follows a predictable inflection: patent/exclusivity expiration and any subsequent generic approval or authorized generic ramp.

What Paragraph IV challenges exist for Zyflo (zileuton), and which companies are signaling generic supply?

A Paragraph IV filing is a high-signal indicator of:

The likely generic applicant(s) that could become suppliers,
The timeline to generic launch,
Where disputes could delay market entry.

Procurement implication: the existence of Paragraph IV filings often predicts near-term supply network additions, even before commercial rollout.

What patent litigation affects Zyflo (zileuton) generic entry and supplier availability?

For supplier planning, the litigation question is not “whether generic supply exists,” but:

whether entry is blocked by court injunctions or delayed settlement terms,
whether a settlement triggered an agreed launch date.

Procurement implication: a supplier strategy should incorporate the settlement or injunction timeline that determines when competing supply can legally move into the market.

How does Zyflo’s regulatory status (FDA approval pathway) affect sourcing: ANDA vs. NDA vs. authorized generic?

For small-molecule products like zileuton, competitors generally seek an ANDA to manufacture and market a generic version after meeting patent and exclusivity constraints.

Key regulatory sourcing checkpoints

ANDA approval date(s) (if any generics are approved)
Label and bioequivalence basis
Interchangeability status (if applicable)
Launch and distribution agreements

Procurement implication: once an ANDA is approved, new suppliers can enter through multiple approved manufacturing sites, subject to ongoing compliance.

Which companies have the largest commercial supply footprint for Zyflo (zileuton) after generic entry?

If generic competition occurs, supply typically concentrates among:

Large generic manufacturers with broad distribution channels, and
CMOs with multiple FDA-approved sites that reduce raw material and production bottlenecks.

Procurement implication: post-generic, supplier availability becomes a function of portfolio scale and manufacturing network redundancy, not NDA holder control.

What formulation-specific IP barriers could limit generic tablet sourcing for Zyflo?

Even for non-biologics, formulation and manufacturing method patents can matter:

tablet composition improvements,
dissolution profile claims,
manufacturing process claims (granulation, compression, coating),
stability-related specifications.

Procurement implication: supplier candidates must clear both legal and technical barriers tied to the exact dosage-form performance requirements.

Zyflo supplier landscape comparison: brand holder vs. potential generic/authorized-generic suppliers

Supplier category	Who supplies	Typical contract model	Main gating factor
Brand NDA holder	Marketing authorization holder’s distribution	Direct/authorized distributor + internal/CMO manufacturing	Patent/exclusivity status on listed drug
Authorized generic	Licensed entity or contract supplier using brand authorization	Supply + repack/distribution agreements	Agreement scope and court/timeline constraints
Generic ANDA applicants	Generic manufacturers	Multi-site manufacturing + distribution contracts	ANDA approval + legal “carve-outs” for patents

Procurement implication: a supplier plan that targets “Zyflo” specifically should treat brand supply and generic supply as different procurement programs with different qualification requirements.

Key Takeaways

Zyflo’s supply chain is driven by the FDA Orange Book applicant (legal supplier channel) and the approved manufacturing sites (operational supplier channel).
The most material constraints on expanding the supplier pool are Orange Book-listed patents and exclusivity, plus any Paragraph IV litigation/settlement timelines.
As generic supply opens, supplier availability typically broadens rapidly through ANDA-approved manufacturing networks, but formulation and process IP can still constrain which generics can launch cleanly.

FAQs

How do I identify the current manufacturer of Zyflo tablets by strength and dosage form?
Use the Zyflo entry in FDA Orange Book and the approved labeling to determine the applicant and then cross-reference manufacturing site approvals tied to that listed drug.
Do DMFs disclose Zyflo API suppliers publicly?
DMF ownership can be referenced via FDA documentation, but site-level disclosure for API suppliers is not always straightforward in public portals; Orange Book and inspection-related facility information are the primary public starting points.
Can authorized generics supply Zyflo even if the brand is under patent protection?
Yes, authorized generics can exist under licensing arrangements that permit supply despite remaining brand patent protections, but the exact eligibility depends on the legal and settlement framework.
What documents matter for supplier qualification for Zyflo?
For procurement and audit, focus on cGMP compliance at the approved manufacturing sites, plus product-specific documentation tied to the approved label and specifications.
What signals indicate generic launch risk for Zyflo?
Paragraph IV filings, court dockets, and settlement agreements tied to Orange Book patents are the key forward signals that change supplier availability.

References (APA)

FDA. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. US Food and Drug Administration.
FDA. Drugs@FDA: FDA Approved Drug Products. US Food and Drug Administration.

Suppliers and packagers for ZYFLO

ZYFLO