List of Excipients in Branded Drug AMPHOTERICIN B

Generic Drugs Containing AMPHOTERICIN B

Company	Ingredient	NDC	Excipient
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	amphotericin b	23155-594	.ALPHA.-TOCOPHEROL, DL-
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	amphotericin b	23155-594	CHOLESTEROL
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	amphotericin b	23155-594	DISTEAROYLPHOSPHATIDYLGLYCEROL, DL-
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	amphotericin b	23155-594	HYDROCHLORIC ACID
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	amphotericin b	23155-594	HYDROGENATED SOYBEAN PHOSPHATIDYLCHOLINE
Heritage Pharmaceuticals Inc d/b/a Avet Pharmaceuticals Inc	amphotericin b	23155-594	SODIUM HYDROXIDE

What are the Most Frequently-Used Excipients in AMPHOTERICIN B?

# Of NDCs	Excipient
1	.ALPHA.-TOCOPHEROL
1	.ALPHA.-TOCOPHEROL, DL-
1	1,2-DISTEAROYL-SN-GLYCERO-3-(PHOSPHO-RAC-(1-GLYCEROL))
2	CHOLESTEROL
1	DEOXYCHOLIC ACID
1	DISTEAROYLPHOSPHATIDYLGLYCEROL, DL-

Amphotericin B Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: August 12, 2026

Amphotericin B is an off-patent antifungal with a commercially valuable formulation problem: the active ingredient has poor aqueous solubility, dose-limiting nephrotoxicity, and formulation-dependent tolerability. The strongest opportunities are not new-molecule patents. They are lipid composition, particle engineering, route-of-administration, manufacturing, stability, and differentiated clinical-use claims.

Liposomal and lipid-complex products demonstrate that excipient selection can support major price and market segmentation. The commercial opportunity is strongest in lower-cost sterile lipid products, improved generic formulations, oral and pulmonary delivery, topical products, veterinary formulations, and region-specific supply.

What excipients are used in approved amphotericin B products?

Approved amphotericin B products use four main excipient strategies: detergent solubilization, liposomes, lipid complexes, and colloidal dispersions.

Product	Active form	Principal excipients or carrier	FDA product type	Formulation objective
Fungizone	Amphotericin B deoxycholate	Sodium deoxycholate, phosphate buffer	Conventional sterile powder for injection	Solubilize amphotericin B in an injectable complex
AmBisome	Liposomal amphotericin B	Hydrogenated soy phosphatidylcholine, cholesterol, distearoylphosphatidylglycerol, alpha-tocopherol, sucrose	Liposomal sterile powder for injection	Reduce free drug exposure and improve tolerability
Abelcet	Amphotericin B lipid complex	Dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol	Lipid-complex injectable suspension	Alter tissue distribution and reduce acute toxicity
Amphocil	Amphotericin B colloidal dispersion	Cholesteryl sulfate	Colloidal injectable dispersion	Create a stable amphotericin B-cholesterol sulfate complex

The formulation choice changes pharmacokinetics, infusion behavior, renal toxicity, storage requirements, manufacturing cost, and regulatory comparability. The products are not interchangeable on an excipient-by-excipient basis.

How does sodium deoxycholate affect amphotericin B performance?

Sodium deoxycholate forms a solubilizing complex with amphotericin B but does not eliminate the drug's membrane toxicity. Conventional amphotericin B deoxycholate has a higher incidence of infusion-related reactions and nephrotoxicity than liposomal amphotericin B. The formulation is inexpensive and has broad global use, but its safety profile limits prolonged therapy and use in patients with renal risk factors (Burgess & Villamarín, 2012).

The commercial value of deoxycholate products is therefore concentrated in hospital formularies, public-health procurement, veterinary medicine, and markets where acquisition cost outweighs administration and monitoring costs.

What excipients protect AmBisome?

AmBisome uses a multilamellar liposomal system comprising hydrogenated soy phosphatidylcholine, cholesterol, distearoylphosphatidylglycerol, alpha-tocopherol, and sucrose. The phospholipids and cholesterol form the lipid bilayer; the negatively charged phospholipid supports drug association; sucrose provides cryo- and lyoprotection during freeze-drying; alpha-tocopherol supports lipid stability (Gilead Sciences, 2023).

This excipient platform is commercially difficult to reproduce because performance depends on more than the ingredient list. Critical variables include:

• lipid purity and oxidation profile;
• lipid-to-drug ratio;
• vesicle size distribution;
• lamellarity;
• surface charge;
• residual solvent and water content;
• reconstitution time;
• free amphotericin B fraction;
• aggregation during storage;
• sterile filtration and aseptic processing.

A generic manufacturer must demonstrate pharmaceutical equivalence and bioequivalence or therapeutic equivalence under the applicable FDA pathway. For complex liposomal products, conventional analytical similarity may not fully predict clinical behavior.

Which excipients are used in Abelcet and Amphocil?

Abelcet uses dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol to create ribbon-like lipid complexes. Amphocil uses cholesteryl sulfate to create a colloidal dispersion. Both approaches reduce exposure to free amphotericin B, but they differ in particle morphology, tissue distribution, preparation, infusion characteristics, and development risks.

For a competing product, substituting one phospholipid, sterol, or charged lipid for another can change the product's identity. A formulation change may create a new drug product rather than a simple generic alternative, particularly where the carrier is essential to safety and pharmacology.

What patents protect amphotericin B formulations?

The original amphotericin B active ingredient is old and is not protected by a commercially meaningful composition-of-matter patent. The relevant intellectual-property assets historically covered:

1. liposomal amphotericin B compositions;
2. lipid-complex structures;
3. colloidal dispersions;
4. particle-size and manufacturing controls;
5. freeze-dried compositions;
6. reconstitution systems;
7. dosing methods intended to reduce toxicity;
8. delivery through pulmonary, oral, topical, or localized routes.

Most first-generation U.S. formulation patents associated with commercial amphotericin B products have reached the end of their statutory terms. Current protection is more likely to arise from later formulation improvements, manufacturing know-how, trade secrets, regulatory exclusivity, or patents covering a new route or clinical use.

How strong is the current patent estate for amphotericin B?

The estate is weak for the conventional injectable active ingredient and stronger for differentiated delivery systems.

Asset category	Current strategic strength	Main reason
Amphotericin B molecule	Low	Historic active-ingredient protection has expired
Deoxycholate injectable	Low to moderate	Established product with limited formulation differentiation
Liposomal injectable	Moderate	Complex product characterization and manufacturing barriers
Lipid-complex injectable	Moderate	Carrier architecture and process controls can be difficult to copy
Oral amphotericin B	Moderate to high	Bioavailability, absorption, and local gut delivery create new claim space
Inhaled amphotericin B	Moderate to high	Device, particle engineering, and pulmonary-use claims add protection
Topical or transdermal products	Moderate	Localized delivery and penetration-enhancement claims
Manufacturing process	Moderate	Trade secrets and process patents may be more durable than composition claims
Veterinary formulations	Moderate	Species, dosing, route, and palatability claims can create a separate market

A new patent filing cannot normally reclaim the expired composition-of-matter term. The defensible strategy is to claim a genuinely different composition, process, device, route, or therapeutic application.

What patent numbers and expiration dates matter?

Historic U.S. amphotericin B formulation patents include early liposomal and lipid-carrier filings dating from the 1980s and 1990s. Their 20-year terms generally expired between the late 2000s and early 2020s, depending on the earliest effective nonprovisional filing date and any patent-term adjustment or extension.

For diligence, the relevant records are:

• the FDA Orange Book for approved prescription products and listed patents;
• USPTO Patent Center for prosecution history and term calculation;
• FDA approval letters and product labeling;
• assignment records for ownership and licensing;
• court dockets for Paragraph IV litigation.

No current patent number should be treated as blocking without checking its live status, terminal disclaimers, patent-term adjustment, maintenance fees, and jurisdiction. A patent family may contain expired composition claims but unexpired continuation claims directed to a narrower process or use.

What is the Orange Book status of amphotericin B?

Amphotericin B is an approved small-molecule antifungal, not a biologic. Biosimilar regulation therefore does not apply. Follow-on products proceed through generic, hybrid, or new-drug pathways rather than the 351(k) biosimilar pathway.

The Orange Book is relevant for:

• Fungizone and conventional amphotericin B injection;
• liposomal amphotericin B products;
• listed formulation or method-of-use patents;
• approved therapeutic-equivalence codes;
• reference-listed drug status.

The commercial significance differs by product. A conventional amphotericin B injection may be suitable for an ANDA if the proposed product can meet the applicable equivalence requirements. A liposomal product is more complex. Its development may require a detailed analytical package, comparative pharmacokinetics, and potentially additional clinical or immunogenicity-related evidence depending on FDA expectations.

FDA's product-specific guidance and current Orange Book listing should control any launch decision. Historic patent expiry alone does not guarantee an ANDA pathway or therapeutic-equivalence rating.

When does amphotericin B lose exclusivity?

The active ingredient lost meaningful exclusivity decades ago. The relevant exclusivity question now concerns individual products and formulations.

Product or opportunity	Exclusivity position
Conventional amphotericin B deoxycholate	Mature, off-patent market
Liposomal amphotericin B	Historic product exclusivity and patent barriers have largely expired
Lipid-complex amphotericin B	Mature product with formulation and manufacturing barriers
Colloidal dispersion	Commercially mature and less widely used
New oral formulation	Potentially eligible for new-drug exclusivity if approved as a qualifying new product
New inhaled formulation	Potential new chemical delivery, method, or device exclusivity
Pediatric indication	Potential pediatric exclusivity if statutory requirements are met
Orphan indication	Potential orphan-drug exclusivity for a qualifying rare disease use

The most attractive exclusivity strategy is to create a clinically differentiated product rather than rely on the old injectable product. An oral formulation that provides reliable exposure, or a pulmonary product that reduces systemic toxicity, could support new patents and regulatory exclusivity.

What generic entry risks exist for amphotericin B?

Generic entry risk is high for conventional amphotericin B and moderate for complex lipid products.

Conventional injectable risk

The deoxycholate product has limited formulation complexity compared with liposomal products. Competition can focus on:

• low-cost active pharmaceutical ingredient supply;
• sterile fill-finish;
• vial configuration;
• global procurement contracts;
• hospital purchasing agreements;
• supply reliability.

Price compression is likely where multiple approved suppliers exist. Manufacturing failures, sterile-capacity shortages, and API supply interruptions can create temporary pricing power.

Liposomal product risk

Liposomal amphotericin B has a higher technical barrier. Generic or follow-on manufacturers must control:

• particle size and distribution;
• encapsulation efficiency;
• free-drug concentration;
• lipid oxidation;
• reconstitution performance;
• release profile;
• storage stability;
• container-closure compatibility;
• infusion compatibility.

The major risk to the incumbent is not only an identical generic. It is a lower-cost liposomal or lipid-associated product that obtains a favorable regulatory designation or wins tenders through comparable clinical performance.

Paragraph IV challenges

Paragraph IV litigation is most relevant when an ANDA applicant certifies that an Orange Book patent is invalid, unenforceable, or not infringed. The core amphotericin B molecule does not create a meaningful current Paragraph IV barrier. Any active challenge would likely target:

• an unexpired liposomal formulation patent;
• a manufacturing process;
• a reconstitution or stability claim;
• a method-of-use patent;
• a later-improvement patent.

The litigation risk should be assessed patent family by patent family. A single unexpired patent may delay launch only if it is listed, enforceable, and broad enough to cover the proposed product.

Which companies compete in amphotericin B?

The commercial field includes originators, generic injectables manufacturers, lipid and sterile-manufacturing specialists, and developers of next-generation delivery systems.

Company or group	Relevant position
Gilead Sciences	Originator and commercial owner associated with AmBisome
Leadiant-linked commercial operations	Historical association with Abelcet commercialization
Generic sterile injectables manufacturers	Conventional amphotericin B and potential follow-on supply
Specialized lipid-drug developers	Liposomal, lipid-complex, and nanoparticle technologies
Contract development and manufacturing organizations	Sterile fill-finish, lipid processing, lyophilization, and analytical comparability
Academic and biotechnology developers	Oral, inhaled, topical, and targeted amphotericin B platforms

Commercial ownership has changed across products and territories. Licensing, distribution, and local registration rights must be checked by country because the U.S. owner, marketing authorization holder, and manufacturing site may differ.

What formulation patents could protect new amphotericin B products?

The most valuable claim areas are formulation and delivery claims that solve a measurable clinical or manufacturing problem.

Oral delivery

Oral amphotericin B has historically faced poor solubility and limited systemic absorption. This problem creates several claim opportunities:

• self-emulsifying drug-delivery systems;
• amorphous solid dispersions;
• lipid nanoparticles;
• ion-pairing or complexation;
• mucoadhesive systems;
• permeability-enhancing excipients;
• targeted intestinal delivery;
• local treatment of gastrointestinal fungal reservoirs.

An oral product may pursue systemic treatment or local gastrointestinal activity. The regulatory and patent strategies differ substantially.

Inhaled delivery

Pulmonary amphotericin B can target fungal colonization and prophylaxis while reducing systemic exposure. Protection may cover:

• spray-dried particles;
• dry-powder inhalers;
• nebulized liposomes;
• aerodynamic diameter;
• moisture protection;
• device-cartridge combinations;
• pulmonary prophylaxis methods;
• dosing schedules for transplant or immunocompromised patients.

The device can create a second patent layer, but it also increases combination-product and usability requirements.

Topical and localized delivery

Topical products may target cutaneous, mucosal, ocular, or vaginal fungal infections. Excipient opportunities include:

• bioadhesive gels;
• nanoemulsions;
• creams and ointments;
• thermosensitive gels;
• ocular suspensions;
• vaginal tablets or films;
• wound dressings;
• sustained-release implants.

The main commercial advantage is reduced systemic toxicity and lower development complexity than an intravenous product, although clinical differentiation must be clear.

How should a company build an amphotericin B excipient strategy?

A practical strategy should separate the excipient platform from the finished dosage form.

1. Select excipients with a defensible supply chain

Priority excipients include pharmaceutical-grade phospholipids, hydrogenated phosphatidylcholine, phosphatidylglycerols, cholesterol, cholesteryl sulfate, sucrose, antioxidants, buffers, and surfactants.

Supplier qualification should examine:

• compendial status;
• residual solvent profile;
• peroxide and aldehyde levels;
• animal-origin status;
• lot-to-lot lipid composition;
• sterile processing capability;
• global regulatory files;
• capacity for commercial-scale supply.

A formulation that depends on a single specialty lipid supplier creates a material launch risk.

2. Use quality-by-design controls

Critical quality attributes should include particle size, polydispersity, morphology, encapsulation, free drug, potency, sterility, endotoxin, residual moisture, and reconstitution time.

Critical process parameters may include lipid hydration temperature, homogenization energy, solvent-removal conditions, filtration, freeze-drying cycle, and vial sealing. These parameters are difficult to reconstruct from public patent documents, making process know-how commercially important.

3. Design around the regulatory pathway

A conventional injectable may fit an ANDA pathway. A materially different liposomal, oral, inhaled, or topical product may require a 505(b)(2) NDA or a full NDA, depending on the proposed formulation, route, clinical claims, and reference product.

The strongest commercial cases are products that can demonstrate one of the following:

• lower nephrotoxicity;
• shorter infusion time;
• improved room-temperature stability;
• lower cold-chain dependence;
• reduced dosing frequency;
• improved pulmonary targeting;
• lower cost than AmBisome;
• improved access in low- and middle-income countries.

What licensing and partnership opportunities exist?

The most valuable partnership opportunities are concentrated in technology transfer and manufacturing rather than in the old active ingredient.

Potential deal structures include:

• licensing a liposomal or nanoparticle platform;
• regional rights for an approved product;
• co-development with a sterile CDMO;
• supply agreements for specialty phospholipids;
• formulation licensing for oral or inhaled delivery;
• government or nonprofit procurement partnerships;
• veterinary distribution agreements;
• technology transfer to emerging-market manufacturers.

A company with excipient know-how but no sterile capacity may license its formulation to a fill-finish manufacturer. A generic injectable company may acquire a validated lipid platform to move from conventional amphotericin B into higher-margin complex products.

What manufacturing and IP barriers affect commercial entry?

The principal barriers are technical rather than molecule-level patent barriers.

Manufacturing barriers

• sterile lipid handling;
• high-shear or high-pressure processing;
• aseptic lyophilization;
• control of lipid oxidation;
• scale-up without changing particle morphology;
• analytical characterization of complex carriers;
• container-closure compatibility;
• validated reconstitution and infusion performance.

IP and know-how barriers

• carrier composition;
• process sequence;
• lipid purity specifications;
• particle-size control;
• lyophilization cycle;
• formulation stability;
• device integration;
• clinical dosing schedules.

Trade secrets can remain valuable after patents expire. A competitor may design around a composition claim but still face a long development program to reproduce commercial quality and clinical performance.

How does amphotericin B compare with competing antifungals?

Amphotericin B remains differentiated by broad antifungal activity and use in severe, invasive infections. Its principal disadvantages are intravenous administration, nephrotoxicity, infusion reactions, and manufacturing complexity.

Product class	Main advantage	Main disadvantage	Commercial implication
Amphotericin B deoxycholate	Low cost and broad activity	Renal toxicity and infusion reactions	Price-sensitive institutional markets
Liposomal amphotericin B	Better tolerability and established efficacy	High acquisition cost and complex manufacture	Premium hospital and transplant markets
Triazoles	Oral options and convenient dosing	Resistance, interactions, and narrower activity in some settings	Strong outpatient competition
Echinocandins	Favorable safety profile	Intravenous administration and limited pathogen coverage	Hospital alternative for selected infections
Newer antifungals	Potentially improved safety or convenience	Higher development and launch costs	Competitive pressure on premium amphotericin products

The best commercial positioning for a new amphotericin formulation is a specific clinical advantage, not a broad claim of improved convenience.

What revenue exposure does amphotericin B create?

Revenue exposure varies sharply by product type.

• Conventional deoxycholate products have high unit-volume potential but low gross margins.
• Liposomal products have lower volume but substantially higher revenue per treatment course.
• Oral formulations could expand treatment into outpatient and chronic-use settings.
• Inhaled products could create prophylaxis markets in transplant and immunocompromised populations.
• Topical and veterinary products offer lower regulatory barriers and diversified demand.
• Specialty excipients and lipid intermediates can generate recurring B2B revenue independent of a finished-drug brand.

The most attractive business model may combine a mature injectable with a proprietary excipient platform. The injectable provides near-term sales, while the platform supports follow-on products and licensing.

What geographic opportunities exist for amphotericin B?

Geographic strategy should distinguish premium markets from access-driven markets.

United States and Europe

The commercial focus is on liposomal products, hospital contracting, supply reliability, and differentiated delivery. Regulatory comparability and sterile manufacturing are the key barriers.

Latin America, Asia, and Africa

Demand is more sensitive to price, supply continuity, and public procurement. Lower-cost deoxycholate and locally manufactured lipid formulations may have strong potential. WHO procurement and national registration requirements can materially affect market access.

Emerging-market manufacturing

Technology transfer for lyophilized conventional products, lipid complexes, and sterile suspensions can create licensing revenue. Local production also reduces freight, cold-chain, and supply interruption risks.

Key Takeaways

• Amphotericin B's active ingredient is long off patent; commercial value lies in formulation, delivery, manufacturing, and supply-chain control.
• Sodium deoxycholate supports low-cost products but does not solve amphotericin B's renal and infusion toxicity.
• Liposomal, lipid-complex, and colloidal formulations create higher technical barriers and premium pricing.
• AmBisome's excipient system depends on lipid composition, particle attributes, lyophilization, and process controls, not merely the listed ingredients.
• Current Paragraph IV risk is product-specific and concentrated in any unexpired formulation, process, or method-of-use patents.
• Amphotericin B is a small molecule, so biosimilar regulation does not apply.
• Oral, inhaled, topical, and localized products offer the clearest new patent and exclusivity opportunities.
• Specialty lipid supply, sterile CDMO services, and emerging-market technology transfer are actionable commercial opportunities.
• The strongest product concept combines measurable toxicity reduction or route-of-administration improvement with a scalable excipient platform.

FAQs

Can amphotericin B be reformulated with polysorbates or cyclodextrins?

Yes, but the excipient must improve solubility or delivery without increasing toxicity, hemolysis, instability, or tissue exposure. A simple solubilizer substitution is unlikely to create durable differentiation unless it produces a clinically meaningful performance advantage.

Are liposomal amphotericin B products interchangeable?

No. Liposomal products may differ in lipid composition, particle structure, free-drug fraction, stability, and pharmacokinetics. Regulatory interchangeability depends on the approved product, equivalence evidence, and applicable FDA requirements.

Is there a commercial opportunity for generic AmBisome?

Yes, but the opportunity has a higher technical and regulatory barrier than conventional amphotericin B deoxycholate. The value depends on demonstrating equivalence, securing specialty lipid supply, and achieving a cost structure below the originator product.

Can an amphotericin B excipient patent block a generic product?

Yes, if the patent is unexpired, enforceable, properly listed where required, and broad enough to cover the proposed composition or process. Expired historical patents do not create a current blocking right.

Which amphotericin B route has the strongest growth potential?

Oral and inhaled delivery have the highest potential for creating new markets and patent estates. Topical and veterinary products may reach commercialization faster, while injectable lipid products offer the clearest near-term hospital opportunity.

References

1. Burgess, B. L., & Villamarín, R. (2012). Liposomal amphotericin B: A review of the current status of the drug. Expert Opinion on Pharmacotherapy, 13(6), 857-866.

2. Gilead Sciences, Inc. (2023). AmBisome (amphotericin B) liposome for injection: Prescribing information. U.S. Food and Drug Administration.

3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

4. U.S. Food and Drug Administration. (2023). Fungizone amphotericin B for injection: Prescribing information. FDA.

5. U.S. Food and Drug Administration. (2023). Abelcet amphotericin B lipid complex injection: Prescribing information. FDA.

6. U.S. Food and Drug Administration. (2023). Amphocil amphotericin B colloidal dispersion: Prescribing information. FDA.

7. World Health Organization. (2023). WHO fungal priority pathogens list to guide research, development and public health action. WHO.