AmBisome for Injection is a sterile, non-pyrogenic lyophilized product for intravenous infusion.

AmBisome is a true single bilayer liposomal drug delivery system. Liposomes are closed, spherical vesicles created by mixing specific proportions of amphophilic substances such as phospholipids and cholesterol so that they arrange themselves into multiple concentric bilayer membranes when hydrated in aqueous solutions. Single bilayer liposomes are then formed by microemulsification of multilamellar vesicles using a homogenizer.

AmBisome consists of these unilamellar bilayer liposomes with amphotericin B intercalated within the membrane. Due to the nature and quantity of amphophilic substances used, and the lipophilic moiety in the amphotericin B molecule, the drug is an integral part of the overall structure of the AmBisome liposomes. AmBisome contains true liposomes that are less than 100 nm in diameter. A schematic depiction of the liposome is presented below.

Cross Section View of AmBisome® Liposome

Note: Liposomal encapsulation or incorporation into a lipid complex can substantially affect a drug’s functional properties relative to those of the unencapsulated drug or non-lipid associated drug. In addition, different liposomal or lipid-complex products with a common active ingredient may vary from one another in the chemical composition and physical form of the lipid component. Such differences may affect the functional properties of these drug products.

Amphotericin B, the active ingredient of AmBisome, acts by binding to the sterol component of a cell membrane, leading to alterations in cell permeability and cell death.

Amphotericin B is a macrocyclic, polyene, antifungal antibiotic produced from a strain of Streptomyces nodosus. It has a molecular formula of C₄₇H₇₃NO₁₇ and a molecular weight of 924.09. The structure of amphotericin B is shown below:

AmBisome has shown in vitro activity comparable to amphotericin B against the following organisms: Aspergillus species (A. fumigatus, A. flavus), Candida species (C. albicans, C. krusei, C. lusitaniae, C. parapsilosis, C. tropicalis), Cryptococcus neoformans, and Blastomyces dermatitidis. However, standardized techniques for susceptibility testing of antifungal agents have not been established and results of such studies do not necessarily correlate with clinical outcome.

The following links provide information about AmBisome indications, safety, and drug interactions:

• Indications
• Safety and Tolerability
• Drug Interactions