Suppliers and packagers for BUSULFEX

BUSULFEX

Listed suppliers include manufacturers, repackagers, relabelers, and private labeling entitities.

Applicant	Tradename	Generic Name	Dosage	NDA	NDA/ANDA	Supplier	Package Code	Package	Marketing Start
Otsuka Pharm	BUSULFEX	busulfan	INJECTABLE;INJECTION	020954	NDA	Otsuka America Pharmaceutical, Inc.	59148-070-91	8 CARTON in 1 CARTON (59148-070-91) / 1 VIAL in 1 CARTON (59148-070-90) / 10 mL in 1 VIAL	1999-02-04

Suppliers and packagers for BUSULFEX

Last updated: June 8, 2026

Busulfex (busulfan) Supplier Landscape: Who Makes It, Who Supplies It, and What IP/Regulatory Constraints Matter

Busulfex is the brand name for intravenous busulfan (busulfan injection) used in conditioning regimens prior to hematopoietic stem cell transplantation (HSCT). The relevant supply question is operational: which companies manufacture the finished drug product, which firms supply key components, and where regulatory and patent status can block substitution.

Who supplies Busulfex (busulfan injection) in the US market?

Busulfex is sold as a sterile, IV busulfan product. In practice, “suppliers” typically map to:

1. the marketing authorization holder / label holder in the US,
2. the manufacturer of record for the finished drug product (DMF/CTD section),
3. contract manufacturers and sterile fill-finish vendors,
4. suppliers of active pharmaceutical ingredient (API) and critical excipients (solvents, diluents, stoppered vial components).

Label holder and finished-product manufacturer

The supplier chain for a specific branded sterile injectables product is anchored to the FDA label and Orange Book listing. For Busulfex, the operational supply decision for procurement and contracting depends on the FDA-registered manufacturer addresses tied to the product label and approval package.

How to map “suppliers” to procurement-relevant entities

For any Busulfex purchase, procurement should treat “supplier” as separate categories:

• Brand/label channel supplier: the company shipping labeled units under NDA ownership.
• Finished drug product manufacturer of record: the specific FDA-registered site(s).
• Fill-finish and sterile manufacturing site(s): often different from API.
• API supplier(s): where busulfan is manufactured (often via DMF-referenced inputs).
• Packaging components supplier: vial, stopper, cap, and any coated parts affecting extractables/leachables.

What active ingredient suppliers make busulfan API used in Busulfex?

Busulfex uses busulfan as the API. In the US, busulfan API for branded and generic busulfan injection is supplied by a limited set of manufacturers that can support:

• injectable-grade specifications,
• tight residual solvent and impurity controls,
• DMF coverage for regulatory filings,
• sterile-compatible excipient compatibility (indirectly via formulation work).

API supply constraints that matter for busulfan IV

For busulfan injectable products, API supply is constrained by:

• impurity profiles and batch consistency for IV use,
• scaling to sterile drug substance requirements,
• ability to support regulatory filings (DMFs) that referencing suppliers can use.

Which companies supply Busulfex excipients and sterile packaging components?

Sterile injectables like Busulfex require consistent supply of:

• sterile aqueous formulation ingredients (solvents, diluents, buffers where used),
• glass vials and compatible closures,
• packaging systems that maintain stability and prevent container closure integrity failures.

Procurement-relevant packaging risks

For HSCT conditioning drugs, supply interruptions often arise from:

• vial/closure shortages,
• container closure integrity issues,
• sterile fill-finish scheduling and aseptic processing capacity constraints.

How does FDA Orange Book status affect sourcing and alternative suppliers for Busulfex?

If Busulfex has active patents listed in the Orange Book for IV busulfan and its specific formulation/method claims, sourcing alternatives can be delayed even if API exists.

What Orange Book status typically governs

• Drug product patent coverage (formulation, stability, or manufacturing process claims)
• Method-of-use coverage (conditioning regimen use)
• Exclusivity periods tied to the NDA approval or supplements

Procurement substitution risk rises sharply when Orange Book protection expires or is vulnerable to challenge.

What patent estate and litigation risks can block new Busulfex suppliers?

Busulfex is a specialized IV oncology conditioning product. IP barriers can block:

• direct generic busulfan injection substitution,
• 505(b)(2) bridges that attempt to use a different formulation route,
• new labeling for dosing schedules.

Where sourcing breaks

Even with manufacturing capacity, new entrants can be blocked by:

• patent injunction risk,
• FDA labeling and interchangeability constraints,
• settlement timelines after Paragraph IV challenges.

What generic or biosimilar entry risks exist for Busulfex?

Busulfex is a small-molecule chemotherapy drug. It does not fall under biosimilar frameworks. The relevant entry risk is generic competition for busulfan injection.

Generic competition gating factors for IV busulfan

• ability to match the reference product’s bioequivalence for IV systemic exposure,
• injectable manufacturing controls,
• stability and impurity control across the shelf-life,
• regulatory acceptance of comparable composition and performance.

Which procurement strategies reduce Busulfex supply disruption risk?

A supplier strategy for Busulfex should focus on operational continuity rather than label-name substitution alone.

Procurement actions that map to supply chain reality

• Contracting for manufacturer-of-record continuity at the lot level.
• Reserving capacity with sterile fill-finish vendors where possible.
• Dual sourcing of compatible injectable presentation components (where label allows).
• Monitoring manufacturing site inspection cadence and sterile aseptic production timelines.

Key Takeaways

• “Suppliers for Busulfex” is best modeled as a chain: label holder, finished drug product manufacturer, sterile fill-finish site, busulfan API supplier, and packaging/excipient suppliers.
• FDA and Orange Book status drives whether additional suppliers can legally and practically compete.
• For IV busulfan conditioning drugs, supply interruptions often come from sterile manufacturing capacity and packaging component availability more than from API alone.

FAQs

1. What is Busulfex’s active ingredient and why does that constrain supplier lists?
2. Can hospitals switch from Busulfex to another IV busulfan product without protocol changes?
3. How do sterile fill-finish capacity constraints affect busulfan injection availability?
4. Do Orange Book patents on IV busulfan delay generic entry and create supplier bottlenecks?
5. What elements of injectable packaging most often disrupt supply for busulfan IV products?

References

1. U.S. Food and Drug Administration. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. (Orange Book).
2. U.S. Food and Drug Administration. Drug Approval Reports and Drug Labels (Busulfex product label).