List of Excipients in Branded Drug IDAMYCIN PFS

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Pfizer Laboratories Div Pfizer Inc	IDAMYCIN PFS	idarubicin hydrochloride	0013-2576	GLYCERIN
Pfizer Laboratories Div Pfizer Inc	IDAMYCIN PFS	idarubicin hydrochloride	0013-2576	HYDROCHLORIC ACID
Pfizer Laboratories Div Pfizer Inc	IDAMYCIN PFS	idarubicin hydrochloride	0013-2576	WATER

Idamycin PFS Excipient Strategy and Commercial Opportunities

Last updated: September 14, 2026

Idamycin PFS is a ready-to-use injectable formulation of idarubicin hydrochloride, an anthracycline used with other antileukemic agents for acute myeloid leukemia. Its formulation is technically simple: an aqueous, preservative-free solution containing idarubicin hydrochloride, sodium chloride, hydrochloric acid and water for injection. The commercial opportunity is therefore unlikely to come from a novel excipient composition alone. The stronger opportunities are safer administration, improved container compatibility, ready-to-use hospital workflow, reduced hazardous-drug exposure and differentiated sterile supply.

What is Idamycin PFS and how is it formulated?

Idamycin PFS contains idarubicin hydrochloride for intravenous administration. The product is supplied as a sterile solution in a prefilled syringe and is intended for administration by healthcare professionals experienced in cytotoxic chemotherapy.[1]

The labeled formulation uses the following excipient strategy:

Component	Formulation role	Commercial significance
Idarubicin hydrochloride	Active pharmaceutical ingredient	Anthracycline cytotoxic agent
Sodium chloride	Tonicity adjustment	Supports an isotonic injectable solution
Hydrochloric acid	pH adjustment and maintenance	Controls chemical stability and solubility
Water for injection	Vehicle	Sterile aqueous medium

The absence of a preservative is commercially relevant. Preservatives can create compatibility, toxicity and regulatory issues in oncology injectables, particularly where the product is administered intravenously to immunocompromised patients. The formulation instead relies on aseptic manufacture, container closure integrity and controlled handling.

Idarubicin hydrochloride is an anthracycline with limited aqueous solubility relative to many conventional small-molecule injectables. The product therefore depends on pH control and a suitable aqueous environment rather than on cosolvents, surfactants or complexation agents. A generic developer changing the excipient system must show that the revised formulation preserves assay, impurities, sterility, particulate control, pH, osmolality and container compatibility.

What excipients protect the commercial performance of Idamycin PFS?

The commercial value of the excipient system comes from functional simplicity and hospital usability rather than from composition-of-matter exclusivity.

Sodium chloride

Sodium chloride supports injectable tonicity. Its use also reduces the need for more complex excipient systems that could introduce extractables, leachables or additional toxicological questions.

The main development risk is not the presence of sodium chloride itself. It is the interaction between tonicity, idarubicin concentration, pH and long-term chemical stability. A formulation with a different sodium chloride level may require comparative stability and, depending on the regulatory pathway, additional justification for clinical relevance.

Hydrochloric acid

Hydrochloric acid is used as a pH-adjusting agent. For idarubicin, pH control can affect solubility, degradation and the impurity profile. The acid is unlikely to create a standalone patent position because it is a conventional pharmaceutical excipient used for a standard formulation function.

A stronger technical position may arise from a narrowly defined pH range combined with:

• a specific idarubicin concentration;
• a defined impurity threshold;
• a particular syringe or polymer barrel;
• protection from light;
• a specified shelf life; and
• a validated sterilization or aseptic-processing method.

Such claims would be formulation or manufacturing claims, not broad excipient claims.

Water for injection

Water for injection is the vehicle. The key requirements are sterility, endotoxin control, particulate control and compatibility with the container closure system. Because the product is a ready-to-use cytotoxic injection, water quality and aseptic processing are central to product release.

What formulation patents could protect an idarubicin prefilled syringe?

A conventional idarubicin solution containing sodium chloride, hydrochloric acid and water for injection is unlikely to support a broad, durable formulation patent by itself. The more defensible patent targets are product-plus-container and process claims.

Potential patent categories

Patent category	Example claim focus	Relative strength
Aqueous composition	Idarubicin concentration, pH and impurity limits	Low to moderate
Prefilled syringe	Syringe barrel, stopper, needle, lubrication and closure integrity	Moderate
Container compatibility	Reduced adsorption, reduced degradation or controlled leachables	Moderate
Light protection	Packaging or syringe system that limits photodegradation	Moderate
Ready-to-use administration	Premeasured dose and connection to a closed-system transfer device	Moderate
Manufacturing process	Aseptic filling, sterilization, hold time and oxygen control	Moderate
Stability package	Long-term stability at defined temperature and light exposure	Moderate if supported by unexpected data
Reduced hazardous-drug exposure	Integrated syringe and transfer system	Potentially strong commercially, but claim scope depends on implementation

Broad claims covering "idarubicin, sodium chloride, hydrochloric acid and water" would face written-description, obviousness and enablement challenges if the formulation is already disclosed in regulatory or patent literature. Commercial value is more likely to come from a combination of formulation and delivery-system features.

When does Idamycin lose exclusivity?

Idamycin's principal active-ingredient exclusivity has expired. Idarubicin is an established small-molecule oncology drug, and generic idarubicin hydrochloride injections have been available in the United States.

The relevant exclusivity framework is:

Protection type	Idamycin status
New chemical entity exclusivity	Expired
Orphan-drug exclusivity	No current blocking period for the legacy product
Pediatric exclusivity	No current blocking period identified for the legacy product
Active patent protection	No broad, commercially meaningful composition-of-matter protection remains
Biosimilar protection	Not applicable
Generic competition	Present or legally available for idarubicin hydrochloride injection

The exact Orange Book status depends on the specific NDA, dosage form and product listing. FDA’s Orange Book identifies approved drug products and listed patents, while FDA’s Drugs@FDA database provides approval and labeling records.[2,3] A current diligence review should treat Idamycin PFS as a mature small-molecule product whose protection depends mainly on manufacturing, supply reliability, packaging and product differentiation.

What is the Orange Book status of Idamycin PFS?

Idamycin PFS is evaluated under the small-molecule drug framework, not the biologics framework. The relevant regulatory questions are:

1. Whether the reference product remains listed as active under its original NDA.
2. Whether the prefilled syringe is separately listed from vial presentations.
3. Whether any patent information remains listed for the relevant reference product.
4. Whether generic applicants have filed ANDAs referencing the applicable product.
5. Whether the proposed generic uses the same dosage form, route and strength.

For a generic developer, the principal pathway is likely an ANDA under section 505(j) of the Federal Food, Drug, and Cosmetic Act if the proposed product can demonstrate pharmaceutical equivalence and bioequivalence to the reference product.[4]

A materially different formulation, a new delivery device or a clinically meaningful new use could require a 505(b)(2) application instead. The distinction matters because a 505(b)(2) product may support a more differentiated label and formulation, but it usually carries greater development and regulatory cost.

Which companies are challenging or competing with Idamycin?

Competition is primarily from generic manufacturers and suppliers of idarubicin hydrochloride injection rather than from biosimilar developers. Idarubicin is a small molecule, so biosimilar approval is not relevant.

The competitive field includes:

• generic sterile-injectable manufacturers;
• branded-generic oncology suppliers;
• contract manufacturers with cytotoxic production capacity;
• hospital and specialty-pharmacy suppliers;
• manufacturers offering vial presentations rather than prefilled syringes; and
• developers of alternative anthracycline products.

Generic competitors can compete on acquisition cost, shortage resilience, package configuration and supply commitments. A prefilled syringe may command a premium if it produces measurable savings in pharmacy compounding, dose preparation, waste, handling time or hazardous-drug exposure.

What commercial opportunities exist for Idamycin excipient and delivery innovation?

1. Ready-to-use cytotoxic presentation

The strongest opportunity is a reliable ready-to-administer presentation. A prefilled syringe can reduce pharmacy preparation steps, lower dosing errors and limit manipulation of a hazardous drug. The value proposition is operational rather than pharmacological.

A successful product would need to demonstrate:

• accurate dose delivery;
• low overfill;
• container closure integrity;
• acceptable syringe glide force;
• low extractables and leachables;
• compatibility with oncology administration sets;
• protection from light; and
• stability through the labeled shelf life.

2. Closed-system drug transfer compatibility

A syringe designed for compatibility with closed-system transfer devices could improve handling safety. The commercial opportunity is strongest where hospitals have established hazardous-drug handling protocols and are willing to pay for reduced preparation complexity.

Patent protection could focus on the connection geometry, transfer sequence, pressure management or integrated closure system. A claim directed only to idarubicin in a syringe would likely be weaker than a claim covering a validated cytotoxic transfer architecture.

3. Reduced waste and dose flexibility

Idarubicin dosing is commonly calculated according to body-surface area and administered in oncology treatment cycles. Prefilled formats may create dose mismatch and product waste if available strengths do not align with prescribed doses.

Commercial opportunities include:

• multiple standardized syringe strengths;
• low-dead-volume syringes;
• dose-specific presentations;
• modular packaging for common body-surface-area doses; and
• improved residual-volume control.

The tradeoff is inventory complexity. More strengths can reduce waste but increase manufacturing changeovers, quality-control testing and hospital stocking requirements.

4. Container and material innovation

The syringe system must resist adsorption, precipitation, discoloration, chemical degradation and particulate formation. Potential approaches include:

• cyclic olefin polymer or cyclic olefin copolymer barrels;
• low-extractable elastomeric plungers;
• reduced-silicone or silicone-free lubrication;
• tungsten-free glass where applicable;
• light-protective secondary packaging; and
• low-permeability closure systems.

The regulatory burden is material-specific. A new polymer or elastomer can trigger extractables and leachables work, stability studies and container-closure integrity testing. The business case depends on whether the material solves a demonstrated problem.

5. Stability extension

A longer shelf life can create commercial value in hospital inventory and shortage management. The most valuable stability improvements would be:

• extended refrigerated shelf life;
• improved room-temperature excursion tolerance;
• reduced sensitivity to light;
• reduced degradation after syringe preparation; and
• defined in-use stability after removal from secondary packaging.

Stability claims must be supported by validated analytical methods capable of distinguishing idarubicin degradation products from formulation and container-related impurities.

How does Idamycin PFS compare with vial-based idarubicin?

Attribute	Idamycin PFS	Vial-based idarubicin
Pharmacy preparation	Minimal or none	Requires withdrawal and dose preparation
Hazardous-drug manipulation	Lower	Higher
Dose flexibility	Limited by prefilled strengths	Higher through withdrawal and dilution
Packaging complexity	Higher	Lower
Unit manufacturing cost	Likely higher	Generally lower
Waste risk	Depends on available strengths	Depends on vial size and dose
Differentiation potential	High	Limited
Device regulatory burden	Higher	Lower
Hospital workflow value	Strong	Conventional

The prefilled syringe has a credible premium position only if it reduces total treatment cost or handling risk. A higher acquisition price without measurable workflow savings will be difficult to defend against vial-based generics.

What patent litigation and Paragraph IV risks affect idarubicin?

Because idarubicin is an old small molecule, the principal Paragraph IV risk is not a challenge to a new active ingredient. It is a challenge to any later-listed formulation, device or method-of-use patent.

Potential Paragraph IV targets could include:

• prefilled-syringe configurations;
• stability claims;
• container-material claims;
• light-protection systems;
• dosing regimens;
• combination therapy methods; and
• manufacturing processes.

A generic applicant could avoid some formulation patents by using a conventional vial, a different syringe material or a different packaging configuration. A patent estate that covers only a narrow PFS architecture may therefore protect a premium presentation but not the broader idarubicin market.

No biosimilar litigation pathway applies. Any litigation would arise under the Hatch-Waxman framework or conventional patent law, not under the Biologics Price Competition and Innovation Act.

What FDA regulatory strategy applies to an improved Idamycin PFS?

The regulatory route depends on the degree of change.

ANDA strategy

An ANDA is most appropriate for a product that matches the reference product in:

• active ingredient;
• strength;
• dosage form;
• route of administration;
• labeling, subject to permitted differences; and
• relevant quality attributes.

A generic applicant seeking a prefilled syringe must also address device constituent requirements and human-factors considerations where applicable.

505(b)(2) strategy

A 505(b)(2) application may be more suitable for:

• a new concentration;
• a materially different excipient system;
• a novel syringe or administration device;
• a new stability profile;
• a new route or dosing regimen; or
• a formulation supported partly by FDA findings for the listed drug.

A 505(b)(2) product can create greater differentiation but may face listed-patent certification, clinical bridging and additional CMC requirements.

How strong is the patent estate for Idamycin PFS?

The underlying idarubicin patent estate is weak as an exclusivity barrier because the active ingredient and conventional injectable use are mature. A new commercial platform could build a stronger, narrower estate around the following combination:

1. a defined idarubicin concentration;
2. a controlled pH and impurity profile;
3. a specified syringe material;
4. a validated closure and lubricant system;
5. light-protective packaging;
6. extended stability; and
7. a hazardous-drug transfer or administration method.

The strength of such an estate would depend on comparative data showing an unexpected result, such as materially lower degradation, reduced adsorption, improved syringe performance or a meaningful reduction in preparation time.

Composition-only protection is likely to be less durable than integrated formulation, container and process protection.

Key Takeaways

• Idamycin PFS is a preservative-free aqueous idarubicin hydrochloride injection using sodium chloride, hydrochloric acid and water for injection.
• The excipient system is conventional and unlikely to support broad standalone patent protection.
• The strongest commercial opportunities are in ready-to-use administration, hazardous-drug handling, container compatibility, dose flexibility and supply reliability.
• Idarubicin is a mature small molecule with no biosimilar risk and limited legacy exclusivity value.
• Generic competition is the main market threat.
• A conventional generic can likely pursue an ANDA, while a materially differentiated syringe or formulation may require a 505(b)(2) strategy.
• The best patent position would combine formulation, syringe materials, stability, packaging and administration-system claims.
• Commercial success depends on hospital workflow savings, not only on excipient novelty.

FAQs

Is Idamycin PFS the same as idarubicin injection?

Idamycin PFS is a prefilled-syringe presentation of idarubicin hydrochloride injection. Vial-based idarubicin products contain the same active ingredient but may differ in container, dose flexibility and pharmacy preparation requirements.

Does Idamycin PFS contain benzyl alcohol or another preservative?

The labeled formulation is described as a preservative-free aqueous solution using sodium chloride, hydrochloric acid and water for injection.[1]

Can a generic company change the excipients in idarubicin injection?

A generic applicant generally must establish equivalence to the reference product. A material excipient change can affect the ANDA strategy and may require additional CMC, stability, compatibility or regulatory justification.

Is a liposomal idarubicin formulation an obvious commercial extension?

Not necessarily. A liposomal product would have different pharmacokinetics, tissue distribution, manufacturing controls and clinical requirements. It would compete as a differentiated formulation rather than as a simple generic equivalent.

What is the most valuable improvement to an idarubicin prefilled syringe?

The highest-value improvement is likely a validated system that reduces hazardous-drug preparation and administration steps while maintaining dose accuracy, stability, container compatibility and reliable hospital supply.

References

1. DailyMed. (n.d.). Idarubicin hydrochloride injection prescribing information. U.S. National Library of Medicine.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs.
4. U.S. Food and Drug Administration. (2024). Abbreviated new drug application submissions: Refuse-to-receive standards.
5. U.S. Food and Drug Administration. (2020). Container closure systems for packaging human drugs and biologics: Chemistry, manufacturing, and controls documentation.