A morphological study of an amphotericin B emulsion-based delivery system

The structure of an amphotericin B emulsion-based delivery system (AmB-E) was investigated using spectroscopic methods (electronic absorption and circular dichroism (CD)), photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM) at various amphotericin B (AmB) concentrations, in comparison with AmB-deoxycholate micelles, Fungizone(R) (Fungi-SS) and free AmB suspension (AmB-SS). Our results show that AmB-E absorption and CD spectra, mean particle size determination by PCS and morphological examination are only weakly concentration-dependent, between 5.10(-5) and 5.10(-7) M, as compared with Fungizone(R) and free AmB suspension. The only difference observed was at high dilution (5.10(-8) M), where AmB dissociation appeared in spectroscopic studies, together with emulsion droplet fusion observed in PC. These data seem to indicate that AmB could be located in the droplets of the emulsion, preferentially in the phospholipid layer, because AmB is not soluble in the oil inner phase. All these results suggest that AmB-E is a system which has potential applications and merits further evaluation. Copyright (C) 1996 Elsevier Science B.V.