An Original Lipid Complex System for Amphotericin

Department of Radiology/Nuclear Medicine, Lucas MRS Imaging Center, Stanford, California, U.S.A. 

Amphotericin B (AmB) is a broad-spectrum antifungal agent that is the antibiotic of choice for disseminated fungal infections, particularly in immunocompromised patients. AmB is also used for the treatment of Leishmaniasis as a second-line treatment. However, its toxicity toward mammalian cells is often dose limiting, whatever its indication. 

AmB has very low bioavailability by the oral route and so has to be given intravenously for the treatment of systemic infections. Due to its insolubility in aqueous media, the traditional formulation is mixed micelles with deoxycholate (Fungizone , Bristol-Myers Squibb). However, the micelles 

The three commercially available AmB formulations differ in their morphology, their composition, and, consequently, their biological activity. AmBisome (developed by Nexstar Pharmaceuticals, commercially available from Gilead Sciences) is a true liposome formulation, consisting of small, unilamellar vesicles (9). Their small size confers a prolonged circulation time 

All three of these new AmB formulations improve the therapeutic index of the drug considerably compared with Fungizone. Larger cumulative doses can be given, leading to cures that were hitherto impossible. However, they are expensive and thus inaccessible in developing countries where their use would be of most benefit (13). 

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